Sample records for barium copper iron

  1. Barium and iron abundances in red giants

    SciTech Connect

    Fernandez-Villacanas, J.L.; Rego, M.; Cornide, M. (Madrid Universidad Complutense (Spain))

    1990-06-01

    An intermediate-dispersion abundance analysis has been carried out on a sample of 21 barium and 14 comparison stars. The excess of barium over iron has been used as the most representative indicator of peculiarity. These excesses are higher in the peculiar stars than in the nonpeculiar stars. Particularly interesting is the case of HD 67447, included in the comparison stars, with an excess Ba/Fe abundance = 1.61, probably a new barium star. A trend indicating a possible anticorrelation between barium overabundance and metallicity favors the suggestion that the barium strong group is older than the barium weak one. 36 refs.

  2. Minimizing iron and copper deposition

    Microsoft Academic Search

    1975-01-01

    A major cause of tube failures in high-pressure subcritical boilers is uncontrolled deposition of corrosion products in internal tube surfaces. The predominant corrosion products are iron oxides, copper, and copper oxides. A water treatment program that controls corrosion products can increase availability and reliability by reducing tube failures and acid cleaning frequency. Such a program includes corrosion product dispersion in

  3. Molecular mediators governing iron-copper interactions.

    PubMed

    Gulec, Sukru; Collins, James F

    2014-01-01

    Given their similar physiochemical properties, it is a logical postulate that iron and copper metabolism are intertwined. Indeed, iron-copper interactions were first documented over a century ago, but the homeostatic effects of one on the other has not been elucidated at a molecular level to date. Recent experimental work has, however, begun to provide mechanistic insight into how copper influences iron metabolism. During iron deficiency, elevated copper levels are observed in the intestinal mucosa, liver, and blood. Copper accumulation and/or redistribution within enterocytes may influence iron transport, and high hepatic copper may enhance biosynthesis of a circulating ferroxidase, which potentiates iron release from stores. Moreover, emerging evidence has documented direct effects of copper on the expression and activity of the iron-regulatory hormone hepcidin. This review summarizes current experimental work in this field, with a focus on molecular aspects of iron-copper interplay and how these interactions relate to various disease states. PMID:24995690

  4. Metabolic crossroads of iron and copper

    PubMed Central

    Collins, James F; Prohaska, Joseph R; Knutson, Mitchell D

    2013-01-01

    Interactions between the essential dietary metals, iron and copper, have been known for many years. This review highlights recent advances in iron-copper interactions with a focus on tissues and cell types important for regulating whole-body iron and copper homeostasis. Cells that mediate dietary assimilation (enterocytes) and storage and distribution (hepatocytes) of iron and copper are considered, along with the principal users (erythroid cells) and recyclers of red cell iron (reticuloendothelial macrophages). Interactions between iron and copper in the brain are also discussed. Many unanswered questions regarding the role of these metals and their interactions in health and disease emerge from this synopsis, highlighting extensive future research opportunities. PMID:20384844

  5. Absorbing properties and structural design of microwave absorbers based on carbonyl iron and barium ferrite

    Microsoft Academic Search

    Y. B. Feng; T. Qiu; C. Y. Shen

    2007-01-01

    Carbonyl iron and barium ferrite powder (BaZn1.5Co0.5Fe16O27) were prepared in this work. The complex permittivity and permeability spectra for rubber radar absorbing materials employing carbonyl iron and barium ferrite powders were measured. A database describing the frequency dependence of the permittivities and permeabilities of the carbonyl iron and barium ferrite microwave absorbers with various powder percentage compositions in 2–18GHz was

  6. Absorbing properties and structural design of microwave absorbers based on carbonyl iron and barium ferrite

    Microsoft Academic Search

    Y. B. Feng; T. Qiu; C. Y. Shen

    2007-01-01

    Carbonyl iron and barium ferrite powder (BaZn1.5Co0.5Fe16O27) were prepared in this work. The complex permittivity and permeability spectra for rubber radar absorbing materials employing carbonyl iron and barium ferrite powders were measured. A database describing the frequency dependence of the permittivities and permeabilities of the carbonyl iron and barium ferrite microwave absorbers with various powder percentage compositions in 2 18

  7. Electrolytic Corrosion of Iron and Copper

    Microsoft Academic Search

    W. F. Higgins

    1954-01-01

    IT is generally accepted that if cast iron and copper are coupled together in a brine solution, the iron, being the less noble member, is likely to suffer corrosion. The copper, on the other hand, will be made `more negative' by contact with the iron and will be prevented in greater or less degree from corroding. The classical work on

  8. Nanoscale inhomogeneities in yttrium-barium-copper-oxide (YBCO) superconductors

    NASA Astrophysics Data System (ADS)

    Islam, Zahirul; Sinha, S. K.; Lang, J. C.; Liu, X.; Haskel, D.; Moss, S. C.; Srajer, G.; Veal, B. W.; Wermeille, D.; Lee, D. R.; Haeffner, D. R.; Welp, U.; Wochner, P.

    2004-03-01

    X-ray diffraction studies at the Advanced Photon Source reveal that nanoscale inhomogeneities, electronic or structural in origin, form in yttrium-barium-copper-oxide (YBa_2Cu_3O_6+x) superconductors and coexist with the superconducting (SC) state. Diffuse scattering from these inhomogeneous superstructures is due to atomic displacements with respect to equilibrium lattice sites (Z. Islam et al. Phys. Rev. B 66, 92501 (2002)), that are characterized by a wavevector of the form q=(q_x,0,0), where qx varies with hole doping from 2 unit cells (along shorter Cu-O-Cu direction) for very low doping to 4 unit cells at optimal doping. Interestingly, while these superstructures are 3-dimensionally ordered when the SC state is weakened (e.g., at x=0.4), as the doping increases, they become quasi 1D with correlation lengths comparable to SC coherence lengths in these cuprates. Recent first-principles calculations (D. de Fontaine et al., to be published) for the x=0.63 compound show that atomic displacements consistent with experimental data can be the result of ordering of O vacancies in YBCO. Models for various superstructures and their role in the phase diagram will be discussed.

  9. Infrared Study of Superconductivity: Grating Coupled Plasmons in Yttrium BARIUM(2) COPPER(3) OXYGEN(7) and Gap Features in BARIUM(1-X) Potassium(x) Bismuth OXYGEN(3)

    Microsoft Academic Search

    Franklin John Dunmore

    1995-01-01

    The electrodynamic properties of two different superconductors, Barium Potassium Bismuth Oxide (BKBO) and Yttrium Barium Copper Oxide (YBCO) have been studied using the technique of transmission Fourier transform spectroscopy with liquid helium temperature bolometric detection. Plasmon resonances have been observed in far infrared transmission measurements on superconducting YBCO films. An Aluminum\\/Nichrome grating is used to couple infrared radiation to collective

  10. Fabrication, characterization and microwave properties of polyurethane nanocomposites reinforced with iron oxide and barium titanate

    E-print Network

    Guo, John Zhanhu

    with iron oxide and barium titanate nanoparticles Z. Guo a,*, S.-E. Lee a , H. Kim a , S. Park a , H.T. Hahn titanate nanoparticles fabricated by the surface-initiated-polymerization approach were investigated the introduction of the dielectric barium titanate nanoparticle into Fe2O3/PU nanocomposites. The permeability

  11. Verification of d-wave pairing symmetry by microwave intermodulation distortion measurements in yttrium barium copper oxide

    E-print Network

    Park, Sang-Hoon, Ph. D. Massachusetts Institute of Technology

    2004-01-01

    We report measurements of the temperature and power dependence of the microwave frequency intermodulation distortion (IMD) in high quality pulsed laser deposition (PLD) Yttrium Barium Copper Oxide (YBCO) on LaAlO3 substrate. ...

  12. Preparation and characterization of isotopic oxygen-enriched yttrium barium copper oxide

    SciTech Connect

    Ott, K.C.; Smith, J.L.

    1988-01-01

    The preparation of labeled superconducting yttrium barium copper oxides from the labeled metal nitrates is described. The materials were characterized by a variety of physical techniques, and their superconducting properties were measured. Trends are seen in the structural parameters of the materials obtained by the nitrate route and also in isotopically enriched materials prepared via gas-phase exchange. These structural changes are accompanied by changes in superconducting properties. The /sup 18/O-enriched yttrium barium copper oxide prepared via the nitrate route has a T/sub c/depressed by 33/degree/K to 59/degree/K, whereas a /sup 17/O sample has a T/sub c/ between the /sup 18/O material and similarly prepared /sup 16/O sample. 15 refs., 1 fig., 3 tabs.

  13. Dielectric Properties and Conductivity of Iron Oxide-Barium Titanate Composites

    Microsoft Academic Search

    A. Kupreviciute; J. Banys; T. Ramoska; R. Sobiestianskas; F. M. M. Alawneh; N. Gharbi; D. C. Lupascu

    2011-01-01

    Sintered composites of iron oxide plus barium titanate in form of core-shell structures are investigated by impedance spectroscopy. The measurements were performed in the frequency and temperature ranges 20 Hz to 1 MHz and 150 K to 510 K, respectively. The composites exhibit strong low-frequency dispersion of electrical modulus and dielectric permittivity which is caused by different mechanisms of electron

  14. Copper Substituted Iron Telluride: A Phase Diagram

    NASA Astrophysics Data System (ADS)

    Valdivia, Patrick; SSRL Beamline 2-1 Collaboration; NIST Bt-1 Collaboration; Birgeneau Group Team

    2014-03-01

    Investigations of superconductivity in the FeCh family (Ch =S,Se,Te) have produced rich physics and notable materials challenges despite the ostensible simplicity of thE system. We have studied the effects of copper substitution in iron-telluride. We map out basic physical parameters of this phase diagram and invesitgate structure-property relationships through a variety of transport and diffraction measurements.

  15. Q factor of dual-tunable microwave resonators based on yttrium iron garnet and barium strontium titanate layered structures

    E-print Network

    Srinivasan, Gopalan

    Q factor of dual-tunable microwave resonators based on yttrium iron garnet and barium strontium of dual-tunable ferrite-ferroelectric hybrid wave microwave resonator was studied as a function of bias 500 m plate of ceramic barium strontium titanate having similar in-plane sizes. A frequency spectrum

  16. Iron and copper release in drinking-water distribution systems.

    PubMed

    Shi, Baoyou; Taylor, James S

    2007-09-01

    A large-scale pilot study was carried out to evaluate the impacts of changes in water source and treatment process on iron and copper release in water distribution systems. Finished surface waters, groundwaters, and desalinated waters were produced with seven different treatment systems and supplied to 18 pipe distribution systems (PDSs). The major water treatment processes included lime softening, ferric sulfate coagulation, reverse osmosis, nanofiltration, and integrated membrane systems. PDSs were constructed from PVC, lined cast iron, unlined cast iron, and galvanized pipes. Copper pipe loops were set up for corrosion monitoring. Results showed that surface water after ferric sulfate coagulation had low alkalinity and high sulfates, and consequently caused the highest iron release. Finished groundwater treated by conventional method produced the lowest iron release but the highest copper release. The iron release of desalinated water was relatively high because of the water's high chloride level and low alkalinity. Both iron and copper release behaviors were influenced by temperature. PMID:17886579

  17. Fabrication, characterization and microwave properties of polyurethane nanocomposites reinforced with iron oxide and barium titanate nanoparticles

    Microsoft Academic Search

    Z. Guo; S.-E. Lee; H. Kim; H. T. Hahn; A. B. Karki; D. P. Young

    2009-01-01

    Polyurethane (PU) nanocomposites reinforced with magnetic iron oxide nanoparticles and\\/or dielectric barium titanate nanoparticles fabricated by the surface-initiated-polymerization approach were investigated. The polymer matrix incorporated with different nanoparticles shows different presenting status surrounding the nanoparticles, i.e., chemical bonding, physical entanglement and bulk polymer chain. The nanoparticles have a different effect on the thermal stability of the polymer nanocomposites. By embedding

  18. Dielectric properties and structural features of barium-iron phosphate glasses

    Microsoft Academic Search

    P. Bergo; S. T Reis; W. M Pontuschka; J. M Prison; C. C Motta

    2004-01-01

    The dielectric constant of barium-iron phosphate glasses with the general composition (40?x)BaO·xFe2O3·(60?x)P2O5 has been investigated at two fixed frequencies (100 kHz and 9.0 GHz). The dielectric constant measured using microwave technique, and the ratio O\\/P of these glasses increase with increasing Fe2O3 content. The structure and valence states of the iron ions in these glasses were investigated using Mössbauer spectroscopy,

  19. The crystallization and structure features of barium-iron phosphate glasses.

    PubMed

    Lu, Mingwei; Wang, Fu; Chen, Kuiru; Dai, Yunya; Liao, Qilong; Zhu, Hanzhen

    2015-09-01

    The crystallization and structure features of xBaO·(90-x)(60P2O5-40Fe2O3)·10CaF2 glasses, where x=0, 5, 10, 15 and 20mol%, are investigated in details by using X-ray diffraction analysis, Fourier transform infrared spectroscopy, Raman spectroscopy and differential thermal analysis. It is found that the major crystalline phase of barium iron phosphate glasses annealed between 650°C and 850°C is FePO4, and the crystallization is restrained by barium. The predominant infrared absorption band is attributed to the antisymmetric stretching vibrations of (PO3)(2-) in Q(1) units. Raman and Fourier transform infrared spectra reveal that the glasses' main structural networks are Q(1) and Q(0) tetrahedrons connected by P-O-P linkages. Moreover, the glass transition temperature increases with BaO content, which suggests that barium can strengthen the thermal stability of the iron phosphate glass. PMID:25863453

  20. Combustion Synthesis of Yttrium BARIUM(2) COPPER(3) OXYGEN(6+X) Superconductor.

    NASA Astrophysics Data System (ADS)

    Lin, Sy-Chyi

    YBa_2Cu_3 O_{rm 6 + x} was produced from copper, barium peroxide, and yttrium oxide by Self-propagating High-temperature Synthesis (SHS) and thermal explosion methods. The SHS process was conducted in two modes: a horizontal combustion and a vertical combustion. The influence of copper particle size on the stability of the reaction front was studied. In contrast to previous studies, a stable reaction front could be maintained even when relatively large copper particles (smaller than 325 mesh) were used. In the horizontal SHS process, large diameter pellets (larger than 22 mm in diameter) enabled stable combustion at room temperature. Elevated ambient temperatures (400 {~} 500^circ C) were needed to stabilize the combustion front movement in small diameter pellets. The product had an average concentration of 84 wt% YBa_2Cu _3O_{rm 6 + x}. In the vertical SHS process, with the aid of a booster, the combustion front moved more rapidly and smoothly than that in the horizontal SHS process and gave a product concentration of about 90 wt% YBa _2Cu_3O_ {rm 6 + x}. High quality product (above 95 wt% YBa_2Cu_3 O_{rm 6 + x}) may be obtained by sintering/calcining the SHS product in an oxygen atmosphere. Three different sintering/calcining processes were studied and the required temperature and the time for each process were determined. The temperature at the center of the pellet in a vertical SHS was measured by thermocouples. The pellet temperature rise is a two step process. The first temperature rise is caused by the oxidation of the copper and the second is caused by the reaction between yttrium oxide and barium cuprate. A reaction mechanism is proposed to explain this behavior. A thermal explosion process was conducted in a continuous rotary kiln. In this mode a pellet was introduced suddenly into a heated rotary kiln causing it to be combusted. After the combustion, the pellet was sintered at 900 to 980 ^circC and a product containing about 95 wt% YBa_2Cu_3 O_{rm 6 + x} was obtained. The impacts of the thermal explosion temperature and the sintering conditions on the product quality were studied. The best temperature was found to be 800 ^circC and 100 minutes was sufficient for the pellet to reach equilibrium.

  1. Iron Nanoparticles in Severe-plastic-deformed Copper

    Microsoft Academic Search

    A. A. Rempel; S. Z. Nazarova; A. I. Gusev

    1999-01-01

    Superparamagnetic iron nanoparticles with a size of a few nanometers were produced in copper by severe plastic deformation. In a isochronal annealing experiment near a temperature of 450?K, which corresponds to the temperature of structural relaxation and the first step of grain growth (from 128 to 150?nm) of submicrocrystalline copper, an abrupt increase in the magnetic susceptibility is detected. This

  2. Reduction of copper sulphate with elemental iron for preparation of copper nanoparticles

    NASA Astrophysics Data System (ADS)

    Nazim, Muhammad

    Reduction of copper sulphate with elemental iron also known as cementation is a well known process used for the recovery of copper for a long time. In this study, the kinetics of the reaction of copper sulphate with iron wire and iron powder has been investigated. The reaction kinetics was studied as a function of different process parameters such as initial concentration, temperature and pH. In this research work, the effects of the above three parameters were studied for both types of iron substrates. It was found that with the iron wire the reaction obeys first order kinetics with respect to copper concentration whereas with the iron powder the order was found to be 1.5. The initial concentration was found to have considerable effect on the reaction kinetics of copper sulphate with elemental iron. The rate of reaction increases with an increase in the initial copper concentration up to a certain level and then decreases for the case of iron wire. However, for the reaction of copper sulphate with iron powder, the reaction rate decreases with an increase in the initial copper concentration. The effect of temperature on the reaction rate of copper sulphate for both types iron substrates (iron wire and iron powder) has also been studied in the temperature range of 23-54ºC. In both the cases, the reaction rate increases with an increase in temperature according to Arrhenius law. The activation energy for the reactions of copper sulphate with iron wire and iron powder was found to be 25.36 kJ/mol and 26.32 kJ/mol, respectively. The copper cementation reaction was found to be suitable to operate at a pH of 2.5-3 for iron wire and a pH of 3-4 for iron powder considering possible inhibition by copper hydroxyl complex formation at higher pH and the possible excess iron consumption by hydrogen reduction at lower pH. The copper particles were produced by the reduction of copper sulphate with elemental iron. The produced copper particles were obtained in the micro to nano range. Nowadays, nano sized particles has potential applications in different engineering and industrial fields. In this research work, emphasis was given to produce copper nano-particles. The reaction of copper sulphate solution with iron wire was studied in the presence of different organic solvents to verify the size and purity of the produced copper particles. 1-butanol proved to be a competent solvent in producing nearly nano sized copper particles with particles size as small as 165 nanometers in the form of clusters and purity as high as 93.67 weight% of copper. In order to determine the copper particles with the smallest size (nano range) and copper purity to a considerable level, characterization was done with the produced copper particles. For this purpose, the effect of sonication, addition of surfactant and chelation by adding EDTA were studied. It can be concluded that nano size copper particles with size less than 100 nm with copper purity of 100% were produced by reaction of 5% copper sulphate solution in the presence of 2 ml surfactant with iron wire and sonication. These copper nano particles have potential applications as catalysts for different industrial organic reactions. Finally, optimization studies of the process parameters effect on the reaction yield of copper sulphate with both types of iron substrates (wire and powder) were carried out using MATLAB 7.0 software. In this study, the relationship between three process variables namely the initial concentration of copper, temperature and pH of solution with reaction yield of copper cementation reaction was investigated for both the cases. Cubic mixture models were developed by using three levels full factorial design to find out the main effects and interactions of these process variables on the reaction yields of copper. The validity of the cubic mixture regressed models have been verified with high regression coefficients and through normal probability curves for residuals. Finally, response surface methodology was used to determine the optimum operating conditions of the cementation re

  3. Effect of zinc on copper and iron bioavailability as influenced by dietary copper and fat source

    SciTech Connect

    Magee, A.C.; Jones, B.P.; Lin, F.; Sinthusek, G.; Frimpong, N.A.; Wu, S.

    1986-03-05

    In a number of experiments, they have observed that liver copper levels of young male rats fed low zinc diets were essentially the same as liver copper levels of rats fed adequate zinc. Liver iron levels of rats fed low zinc diets, however, tended to be markedly higher than liver iron levels of rats fed adequate zinc. Increases in dietary zinc (up to 200 ppm) were generally associated with decreases in liver iron deposition, but had little effect on liver copper deposition. Iron bioavailability appeared to be enhanced when fat sources high in saturated fatty acids were used, and there was evidence that the type of dietary fat influenced the effect of zinc on iron bioavailability. Liver copper deposition, however, did not appear to be markedly affected by the type of dietary fat suggesting that copper bioavailability is less affected by fat source. Increases in dietary copper were associated with increases in liver copper levels and decreases in liver iron levels of rats fed increasing levels of zinc. These data suggest that potential interrelationships between dietary factors not being considered as experimental variables could have significant effects on results and on the interrelationships between dietary variables which are being studied.

  4. New Aspects of Copper and Iron Metabolism in the Myelodysplastic Syndromes

    Microsoft Academic Search

    Judit Várkonyi; Terézia Szabó; Piroska Sebestyén; Attila Tordai; Hajnalka Andrikovics; Géza Kollai; István Karádi

    2006-01-01

    Background: Myelodysplastic syndrome (MDS) is an iron overload condition. Copper deficiency itself might induce dysplastic changes and iron overload. The relationship between the iron and copper metabolism is analyzed in MDS patients. Methods: Copper, iron and ceruloplasmin levels were established, and transferrin saturation determination and HFE mutation analysis were performed in 32 MDS patients. Results: Eleven of 32 MDS patients

  5. The effect of copper on iron reduction and its application to the determination of total iron content in iron and copper ores by potassium dichromate titration.

    PubMed

    Hu, Hanjun; Tang, Yang; Ying, Haisong; Wang, Minghai; Wan, Pingyu; Jin Yang, X

    2014-07-01

    The International Standard Organization (ISO) specifies two titrimetric methods for the determination of total iron content in iron ores using potassium dichromate as titrant after reduction of the iron(III) by tin(II) chloride and/or titanium(III) chloride. These two ISO methods (ISO2597-1 and ISO2597-2) require nearly boiling-point temperature for iron(III) reduction and suffer from copper interference and/or mercury pollution. In this study, potassium borohydride was used for reduction of iron(III) catalyzed by copper ions at ambient temperatures. In the absence of copper, iron(III) reduction by potassium borohydride was sluggish while a trace amount of copper significantly accelerated the reduction and reduced potassium borohydride consumption. The catalytic mechanism of iron(III) reduction in sulfuric acid and hydrochloric acid was investigated. Potassium borohydride in sodium hydroxide solution was stable without a significant degradation within 24h at ambient conditions and the use of potassium borohydride prepared in sodium hydroxide solution was safe and convenient in routine applications. The applicability of potassium borohydride reduction for the determination of total iron content by potassium dichromate titration was demonstrated by comparing with the ISO standard method using iron and copper ore reference materials and iron ore samples. PMID:24840467

  6. Defects, Flux Pinning, and Changes of Copper Stoichiometry in Superconducting Yttrium Barium Copper Oxide

    NASA Astrophysics Data System (ADS)

    Fendorf, Mark John

    1992-01-01

    The purpose of this research is to understand the mechanism by which phase changes related to CuO plane (Cu-O chain layer) occupation initiate and propagate in superconducting YBaCuO. Phase changes of this type, where only the number of CuO layers in a unit cell changes, lead to a family of related crystal structures with stoichiometries Y_2Ba_4Cu _{rm 6 + x}O _{14 + x}, where the number of CuO planes per Ba-Y-Ba sequence is (x + 2) /2. Three superconducting phases, corresponding to x = 0 (single CuO layer), x = 1 (alternating single and double CuO layers), and x = 2 (double CuO layer), are known to exist in this system. A barrier to the development of high-Tc superconductor devices is limited current carrying capacity, and so synthesis of YBaCuO with enhanced critical current density is an important practical development. Because the above microstructure is associated with the 1-2-4/1-2-3 (x = 2 to x = 0) phase transformation, mixed-phase YBaCuO material was synthesized by "partially converting" pure YBa_2Cu _4O_8 to structures of lower copper content under a variety of temperature and pressure conditions. Micrographs reveal dislocations and stacking faults associated with the diffusion of copper and oxygen as transformation progresses. Based on these experimental images, as well as published studies of diffusion in YBa_2Cu_3O _7, an atomic mechanism involving the intercalation and removal of extra CuO planes by partial dislocation climb is developed for changes in the layered YBaCuO crystal structure. An intercalation model is consistent with the known path for oxygen diffusion in YBa_2 Cu_3O_7, and explains observed transformation behavior without invoking diffusion along the c-axis of the crystal structure. The size of the strain fields surrounding stacking faults in YBaCuO suggests that such structures may arise as a result of relatively long-range (~100A interactions), which would make them equilibrium phases in an appropriate temperature range. Investigation of YBaCuO thin films also reveals the presence of many CuO stacking faults, and numerous other crystallographic defects as well. A type of screw dislocation is seen which indicates the films have grown via a spiral growth mechanism. Both the screw dislocations and CuO stacking faults have favorable geometry for flux pinning, and this would explain high critical current values found in most YBaCuO films. (Abstract shortened by UMI.).

  7. Aes, Leed, and UPS Studies of Fcc Iron Epitaxially Grown on COPPER(110) and COPPER(111)

    Microsoft Academic Search

    Hang-Gi. Min

    1988-01-01

    AES, LEED, and, UPS were used to investigate the growth mode, diffusion effect, diffraction pattern, work function, and electronic structure of iron deposited on copper (100) and (111) surfaces. Initially iron grows epitaxially in the fcc structure in an almost layer-by -layer mode for the first 17 layers on the Cu(100) face and 4 ~ 5 layers on the Cu(111)

  8. Effect of oxygen, methyl mercaptan, and methyl chloride on friction behavior of copper-iron contacts

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1978-01-01

    Sliding friction experiments were conducted with an iron rider on a copper disk and a copper rider on an iron disk. The sputter cleaned iron and copper disk surfaces were saturated with oxygen, methyl mercaptan, and methyl chloride at atmospheric pressure. Auger emission spectroscopy was used to monitor the surfaces. Lower friction was obtained in all experiments with the copper rider sliding on the iron disk than when the couple was reversed. For both iron and copper disks, methyl mercaptan gave the best surface coverage and was most effective in reducing friction. For both iron and copper disks, methyl chloride was the least effective in reducing friction. With sliding, copper transferred to iron and iron to copper.

  9. The effects of copper and iron deficiencies in the chick 

    E-print Network

    McGhee, Flin Cameron

    1964-01-01

    THE EFFECTS OF COPPER AND IRON DEFICIENCIES IN THE CHICK A Thesis By Flin C. McGhee Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1964... Major Subject: Biochemistry and Nutrition THE EFFECTS OF COPPER AND IRON DEFICIENCIES IN THE CHICK A Thesis By Flin C. McGhee Appro ed as o style and content by: UC C. M. Lym n, P . D M. Ferguso Ph. D. N. C, Rose, P . D. , . ~p...

  10. Copper Nqr and NMR Study of Metal-Substituted Yttrium BARIUM(2) COPPER(3) OXYGEN(7) and Yttrium BARIUM(2) COPPER(4) OXYGEN(8)

    NASA Astrophysics Data System (ADS)

    Cheng, Show-Jye

    Pulsed nuclear quadrupole resonance (NQR) and nuclear magnetic resonance (NMR) have been used to investigate the effect of metal-substitution for copper in YBa_2Cu_3O_7 (YBCO123) and YBa_2Cu_4O_8 (YBCO124). Among many metal substitutions, Zn has an especially dramatic effect in suppressing the superconducting temperature T_{c}, and hence superconductivity. More interesting is that Zn and Fe have the same T_{c} suppression effect in YBCO124. This study focuses on the Zn substitutions in YBCO123 and Zn, Fe, and Co substitutions in YBCO124. In Zn doped YBCO123, Cu(2), plane site, NQR spectra and the frequency dependence of the spin-lattice relaxation rates have been measured over a temperature range from 77 K to 300 K to study the correlation of the suppression of the relaxation rate with the distance between the probe Cu nuclei and the impurity. It is found that the relaxation rate is insensitive to the variation of the NQR resonance frequency. However, by comparing the results of the Zn doped YBCO124 with those of YBCO123, it can be concluded that the suppression of the relaxation rate for both YBCO compounds in the normal state is caused by destruction of short-range antiferromagnetic correlation with substitution of nonmagnetic ion Zn on the Cu(2) sites. NQR and NMR measurements were carried out on both Cu(2), plane, and Cu(1), chain sites, for various concentrations of Zn, Fe, and Co dopants in YBCO124 over a temperature range from 77 K to 300 K. A strong correlation of the enhancement of Cu(2) spin lattice relaxation rate and suppression of superconductivity by impurities was found. The temperature dependence of the Cu(2) NMR linewidth exhibits a strong RKKY type exchange interaction below 225 K for Zn and Fe doped samples, which indicates the formation of the local magnetic moment. The enhancement of the relaxation rate is caused by the local magnetic moment Fe^ {+3} ion and the moments on Cu(2) neighbors when Zn^{+2} is substituted on Cu(2). This study gives us a clear picture of the spin pseudogap behavior in the high temperature superconductor cuprates. It also suggests that the magnetic moment on the CuO_2 plane may relate to the suppression of T_{c} in metal-substituted YBCO124.

  11. Genotoxicity and mutagenicity of iron and copper in mice

    Microsoft Academic Search

    Daniel Prá; Silvia Isabel Rech Franke; Raquel Giulian; Maria Lúcia Yoneama; Johnny Ferraz Dias; Bernardo Erdtmann; João Antonio Pêgas Henriques

    2008-01-01

    The toxicity of trace metals is still incompletely understood. We have previously shown that a single oral dose of iron or\\u000a copper induces genotoxic effects in mice in vivo, as detected by single cell gel electrophoresis (comet assay). Here, we report\\u000a the effect of these metals on subchronic exposure. Mice were gavaged for six consecutive days with either water, 33.2 mg\\/kg\\u000a iron,

  12. Multiple mechanisms account for lower plasma iron in young copper deficient rats

    PubMed Central

    Pyatskowit, Joshua W.

    2009-01-01

    Copper deficiency lowers brain copper and iron during development. The reduced iron content could be due to hypoferremia. Experiments were conducted to evaluate plasma iron and “ferroxidase” hypotheses by determining copper and iron status of Holtzman albino rats following gestational/lactational copper deficiency. Copper deficient (Cu?) dams on treatment for 5 weeks, two of gestation and three of lactation, had markedly lower copper content of milk and mammary tissue, and lower milk iron. Newborn pups from Cu? dams had lower copper and iron concentrations. Compared to Cu+ pups, Cu? pups, analyzed between postnatal age (P) 0 and P26, were smaller, anemic, had lower plasma iron, cardiac hypertrophy, and near zero ceruloplasmin activity. Liver copper in Cu+ pups increased then decreased during development and major reductions were evident in Cu? pups. Liver iron in Cu+ pups decreased with age while nursing but increased after eating solid food. Liver iron was lower in Cu? pups at P0 and P13 and normal at P20 and P26. Small intestinal copper decreased with age in Cu+ pups and was lower in Cu? pups. Intestinal iron levels in Cu- pups were higher than Cu+ pups postweaning in some experiments. Reduction in plasma iron in Cu? pups is likely due to a decreased “ferroxidase” function leading to lower placental iron transport, a lower milk iron diet, and partial block in iron uptake from intestine but is not due to failure to mobilize hepatic iron, in contrast to older rats eating diet with adequate iron. PMID:18038202

  13. Infrared Study of Superconductivity: Grating Coupled Plasmons in Yttrium BARIUM(2) COPPER(3) OXYGEN(7) and Gap Features in BARIUM(1-X) Potassium(x) Bismuth OXYGEN(3)

    NASA Astrophysics Data System (ADS)

    Dunmore, Franklin John

    1995-01-01

    The electrodynamic properties of two different superconductors, Barium Potassium Bismuth Oxide (BKBO) and Yttrium Barium Copper Oxide (YBCO) have been studied using the technique of transmission Fourier transform spectroscopy with liquid helium temperature bolometric detection. Plasmon resonances have been observed in far infrared transmission measurements on superconducting YBCO films. An Aluminum/Nichrome grating is used to couple infrared radiation to collective two-dimensional plasma modes. The plasmon dispersion is measured by using different grating periods. The strength of the plasma resonances weaken, then disappear as the temperature approaches the critical temperature. The results are analyzed using a grating coupler theory that includes the hybridization of the plasmons with the diffraction modes. Data taken in a magnetic field of up to 12 Tesla are characteristic of the real part of the conductivity of the YBCO film increasing with field, behavior similar to that with increasing of temperature. These results are consistent with the inducement of vortices in the YBCO film. The far infrared transmission of BKBO thin films, grown on Magnesium Oxide (MgO) substrates, was measured in the frequency range from 15 to 200 wavenumbers, and temperature range from 9 to 100 Kelvin. There is a BCS -like peak in the transmission spectrum. The strong coupling Eliashberg theory gives a better description of the optical data than the weak coupling Mattis-Bardeen theory. For an 18 Kelvin critical temperature (T_{c }) sample the Eliashberg model extrapolated to zero temperature gives a London penetration depth of 5500+/-100A and an energy gap of 6.2 meV (50.1 wavenumbers, or 4.0 kT_{c }). Because BKBO is in the dirty limit, the strong coupling characteristics in the optical conductivity is adequately described by the Allen-Dynes parameter only, as opposed to the full Holstein structure due to the electron -phonon interaction alpha^2F(omega). .

  14. Copper-substituted iron telluride: A phase diagram

    NASA Astrophysics Data System (ADS)

    Valdivia, Patrick N.; Kim, Min Gyu; Forrest, Thomas R.; Xu, Zhijun; Wang, Meng; Wu, Hui; Harringer, Leland W.; Bourret-Courchesne, Edith D.; Birgeneau, Robert J.

    2015-06-01

    We have studied the structure, magnetic, and transport properties of copper-substituted iron telluride. Our results extend the range of copper substitution to 60% substitution per formula unit, which is far beyond previously stated solubility limits. Substitution of copper into antiferromagnetic iron telluride is found to suppress the signatures of the low-temperature transitions in susceptibility and resistance measurements, giving rise to an insulating, spin-glass state. Upon increasing the copper substitution from 4% to 6%, short-range antiferromagnetic order appears followed by the combined magnetic and structural transition at a lower temperature, although the magnetic order is ultimately not resolution limited with a correlation length of 250 Å in the 6% Cu-substituted sample, in contrast to the magnetic order of the 4% copper-substituted sample, which is resolution limited. Upon warming the 6% Cu-substituted sample in the presence of a 5 T magnetic field oriented along the b axis, magnetic and structural phase transitions are observed at a temperature much lower than those of the magnetic and structural transitions which occur in zero field. Furthermore, these transitions are absent upon cooling in this field. We discuss the field results in the most general terms possible, including possible random field effects.

  15. Identification of the man-made barium copper silicate pigments among some ancient Chinese artifacts through spectroscopic analysis

    NASA Astrophysics Data System (ADS)

    Li, Q. H.; Yang, J. C.; Li, L.; Dong, J. Q.; Zhao, H. X.; Liu, S.

    2015-03-01

    This article describes the complementary application of non-invasive micro-Raman spectroscopy and energy dispersive X-ray fluorescence spectrometry to the characterization of some ancient Chinese silicate artifacts. A total of 28 samples dated from fourth century BC to third century AD were analyzed. The results of chemical analysis showed that the vitreous PbO-BaO-SiO2 material was used to sinter these silicate artifacts. The barium copper silicate pigments including BaCuSi4O10, BaCuSi2O6 and BaCu2Si2O7 were widely identified from colorful areas of the samples by Raman spectroscopy. In addition, other crystalline phases such as Fe2O3, BaSi2O5, BaSO4, PbCO3 and quartz were also identified. The present study provides very valuable information to trace the technical evolution of man-made barium copper silicate pigments and their close relationship with the making of ancient PbO-BaO-SiO2 glaze and glass.

  16. Identification of the man-made barium copper silicate pigments among some ancient Chinese artifacts through spectroscopic analysis.

    PubMed

    Li, Q H; Yang, J C; Li, L; Dong, J Q; Zhao, H X; Liu, S

    2015-03-01

    This article describes the complementary application of non-invasive micro-Raman spectroscopy and energy dispersive X-ray fluorescence spectrometry to the characterization of some ancient Chinese silicate artifacts. A total of 28 samples dated from fourth century BC to third century AD were analyzed. The results of chemical analysis showed that the vitreous PbO-BaO-SiO2 material was used to sinter these silicate artifacts. The barium copper silicate pigments including BaCuSi4O10, BaCuSi2O6 and BaCu2Si2O7 were widely identified from colorful areas of the samples by Raman spectroscopy. In addition, other crystalline phases such as Fe2O3, BaSi2O5, BaSO4, PbCO3 and quartz were also identified. The present study provides very valuable information to trace the technical evolution of man-made barium copper silicate pigments and their close relationship with the making of ancient PbO-BaO-SiO2 glaze and glass. PMID:25541398

  17. 1. Introduction Copper, along with iron active sites dominate the field of

    E-print Network

    Chen, Peng

    #12;1. Introduction Copper, along with iron active sites dominate the field of biological oxygen chemistry[1] and play important roles in homogeneous[2] and heterogeneous catalysis.[3, 4] Copper pro- teins heme ± iron centers).[8] The known copper proteins which are involved in dioxygen binding, activation

  18. A three-dimensional hydrodynamical line profile analysis of iron lines and barium isotopes in HD 140283

    NASA Astrophysics Data System (ADS)

    Gallagher, A. J.; Ludwig, H.-G.; Ryan, S. G.; Aoki, W.

    2015-07-01

    Context. Heavy-elements, i.e. those beyond the iron peak, mostly form via two neutron capture processes: the slow (s-) and the rapid (r-) process. Metal-poor stars should contain fewer isotopes that form via the s-process, according to currently accepted theory. It has been shown in several investigations that theory and observation do not agree well, raising questions on the validity of either the methodology or the theory. Aims: We analyse the metal-poor star HD 140283, for which we have a high quality spectrum. We test whether a three-dimensional (3D) local thermodynamic equilibrium (LTE) stellar atmosphere and spectrum synthesis code permits a more reliable analysis of the iron abundance and barium isotope ratio than a one-dimensional (1D) LTE analysis. Methods: Using 3D hydrodynamical model atmospheres, we examine 91 iron lines of varying strength and formation depth. This provides us with the star's rotational speed. With this, we model the barium isotope ratio by exploiting the hyperfine structure of the singly ionised 4554 Å resonance line, and study the impact of the uncertainties in the stellar parameters. Results: The star's rotational speed was found to be 1.65 ± 0.05 km s-1. Barium isotopes under the 3D paradigm show a dominant r-process signature as 77 ± 6 ± 17% (fodd = 0.38 ± 0.02 ± 0.06) of barium isotopes form via the r-process, where errors represent the assigned random and systematic errors, respectively. We find that 3D LTE fits reproduce iron line profiles better than those in 1D, but do not provide a unique abundance (within the uncertainties). However, we demonstrate that the isotopic ratio is robust against this shortcoming. Conclusions: Our barium isotope result agrees well with currently accepted theory regarding the formation of the heavy-elements during the early Galaxy. The improved fit to the asymmetric iron line profiles suggests that the current state of 3D LTE modelling provides excellent simulations of fluid flows. However, the abundances they provide are not yet self-consistent. This may improve with non-LTE considerations and higher resolution models. Based on observations taken using the Subaru Telescope High Dispersion Spectrograph (HDS), operated by the National Astronomical Observatory of Japan.

  19. Iron, Copper, and Zinc Distribution of the Cerebellum

    Microsoft Academic Search

    Bogdan F. Gh. Popescu; Christopher A. Robinson; Alex Rajput; Sheri L. Harder; Helen Nichol

    2009-01-01

    Synchrotron rapid-scanning X-ray fluorescence (RS-XRF) is employed for the first time to simultaneously map iron, copper,\\u000a and zinc in the normal cerebellum. The cerebellum is a major repository of metals that are essential to normal function. Therefore,\\u000a mapping the normal metal distribution is an important first step towards understanding how multiple metals may induce oxidative\\u000a damage, protein aggregation, and neurotoxicity

  20. Copper, iron and zinc in Alzheimer's disease senile plaques

    Microsoft Academic Search

    M. A Lovell; J. D Robertson; W. J Teesdale; J. L Campbell; W. R Markesbery

    1998-01-01

    Concentrations of copper (Cu), iron (Fe) and zinc (Zn) were measured in the rims and cores of senile plaques (SP) and in the neuropil of the amygdala of nine Alzheimer's disease (AD) patients and in the neuropil of the amygdala of five neurologically normal control subjects using micro particle-induced X-ray emission (micro-PIXE). Comparison of SP rim and core values revealed

  1. Methods for making a supported iron-copper catalyst

    DOEpatents

    Dyer, Paul N. (Allentown, PA); Pierantozzi, Ronald (Macungie, PA)

    1986-01-01

    A catalyst is described for the synthesis of hydrocarbons from CO+H.sub.2 utilizing a porous Al.sub.2 O.sub.3 support impregnated with iron and copper and optionally promoted with an alkali metal. The use of an Al.sub.2 O.sub.3 support results in the suppression of heavy waxes (C.sub.26 + hydrocarbons), particularly in slurry phase operation, when compared to unsupported or co-precipitated catalysts.

  2. The effect of copper precipitation on hydrogen embrittlement in iron

    Microsoft Academic Search

    N. Takano; Y. Yokka; F. Terasaki

    2004-01-01

    On the hydrogen embrittlement of Fe–1.0mol% Cu and Fe–1.5mol% Cu alloys, the effect of the copper precipitation hardening was studied. The hydrogen diffusivity in the solution treated Fe–Cu alloy is smaller than that in pure iron, and approaches it as the strength increases by aging. On the contrary, the hydrogen concentration in the solution treated Fe–Cu alloy is larger than

  3. Role of Surface Precipitation in Copper Sorption by the Hydrous Oxides of Iron and Aluminum

    E-print Network

    Chorover, Jon

    Role of Surface Precipitation in Copper Sorption by the Hydrous Oxides of Iron and Aluminum K. G precipitation; sorption; isotherms; X-ray diffraction; hydrous iron oxide; hydrous aluminum oxide; copper. INTRODUCTION Hydrous oxides of iron (HFO) and aluminum (HAO) are important mineral components of natural

  4. Copper, ceruloplasmin, superoxide dismutase and iron parameters in Parkinson's disease.

    PubMed

    Tórsdóttir, G; Kristinsson, J; Sveinbjörnsdóttir, S; Snaedal, J; Jóhannesson, T

    1999-11-01

    In a previous study we found copper dyshomeostasis in patients with Alzheimer's disease. In this study, levels of copper in plasma, of ceruloplasmin in serum and ceruloplasmin oxidative activity as well as superoxide dismutase (SOD) activity in erythrocytes were determined in 40 patients with Parkinson's disease and their healthy age- and gender-matched controls. Copper concentrations did not differ significantly in the two groups, whereas both ceruloplasmin concentrations and ceruloplasmin oxidative activity were significantly lower in the patients, also relative to ceruloplasmin mass. SOD activity was not significantly different in the two groups but decreased significantly with the duration of disease. The same was found for ceruloplasmin oxidative activity. Ceruloplasmin oxidative activity and SOD activity did not decrease with age. Levels of serum iron, serum ferritin and total iron binding capacity were determined in about 30 of the patients and an equal number of controls and were not found to differ. Transferrin levels were significantly lower in the patients than in their controls but, conversely, the transferrin saturation was significantly higher in the patients. The results indicate that patients with Alzheimer's disease and Parkinson's disease have defective ceruloplasmin and SOD activities in common and that these defects are not necessarily associated with major disturbances in iron homeostasis. PMID:10608487

  5. Influences of water treatment process on iron and copper release in distribution system.

    PubMed

    Shi, Baoyou; Xiao, Weizhong; Taylor, James S

    2006-01-01

    A pilot study was conducted to assess the effect of water quality changes on iron and copper release in distribution systems. Three finished waters were prepared from groundwater source by conventional treatment, lime softening and reverse osmosis (RO). To mimic desalinated seawater, sea salts were added to RO treated water. Both lime softening and RO treatment significantly decreased the calcium concentration and alkalinity of groundwater. During a yearlong investigation, the impact of seasonal changes on iron and copper release was also evaluated. The results showed that groundwater after lime softening slightly increased iron release potential but significantly decreased copper release. Desalination water caused much higher iron release but lower copper release than conventionally treated groundwater. Blended water with conventional groundwater and desalination water resulted in intermediate iron release but much high copper release. Both iron and copper release could be accelerated by temperature increase. PMID:16835119

  6. Nuclear magnetic resonance of iron and copper disease states

    SciTech Connect

    Runge, V.M. (Vanderbilt Univ., Nashville, TN); Clanton, J.A.; Smith, F.W.; Hutchison, J.; Mallard, J.; Partain, C.L.; James, A.E. Jr.

    1983-11-01

    The tissue levels of paramagnetic ions are an important factor in the determination of T/sub 1/ values as observed by nuclear magnetic resonance (NMR) imaging. The increased levels of iron present in human disease states such as hemochromatosis lead to decreased T/sub 1/ values. The mean liver T/sub 1/ of three patients with iron storage disease was determined to be 130 msec, significantly different from the value of 154 msec, the mean for 14 normal controls. Whether NMR will be able to detect the increased copper levels in liver and brain in Wilson disease remains for further clinical trials to evaluate. NMR imaging, however, does serve as a noninvasive method for the diagnosis of states of iron overload and as a technique to follow progression of disease or response to medical therapy.

  7. A three-dimensional hydrodynamical line profile analysis of iron lines and barium isotopes in HD140283

    E-print Network

    Gallagher, A J; Ryan, S G; Aoki, W

    2015-01-01

    Heavy-elements, i.e. those beyond the iron peak, mostly form via two neutron capture processes: the s- and r-process. Metal-poor stars should contain fewer isotopes that form via the s-process, according to currently accepted theory. It has been shown in several investigations that theory and observation do not agree well, raising questions on the validity of either the methodology or the theory. We analyse the metal-poor star HD140283, for which we have a high quality spectrum. We test whether a 3D LTE stellar atmosphere and spectrum synthesis code permits a more reliable analysis of the iron abundance and barium isotope ratio than a 1D LTE analysis. Using 3D model atmospheres, we examine 91 iron lines of varying strength and formation depth. This provides us with the star's rotational speed. With this, we model the barium isotope ratio by exploiting the hyperfine structure of the singly ionised 4554 resonance line, and study the impact of the uncertainties in the stellar parameters. HD140283's vsini = 1.65 ...

  8. Phytoplankton copper requirement under iron limited condition in the coastal Bay of Bengal

    NASA Astrophysics Data System (ADS)

    Biswas, H.; Bandyopadhyay, D.; Kumar, P. P.

    2012-04-01

    Copper, a redox reactive transition metal, plays a vital role in many cellular redox reactions. Recent investigations show that many eukaryotic microorganisms including marine and coastal diatom utilize copper to perform a high affinity iron acquisition mechanism and the requirement of copper increases with decreasing iron concentrations. However, very less information is available about the role of copper in diatom physiology. Here we report for the first time about the copper utilization by coastal diatom during iron limited condition in the Bay of Bengal coast. The diatom Chaetoceros gracilis was isolated from the Visakhapatnam coast and was grown in different copper concentrations (15nM -1000nM). The concentration of total chlorophyll, the growth rate, the concentration of biogenic silica, the ratio of biogenic silica to particulate organic carbon and the ratio of total chlorophyll to particulate organic carbon were found to be increased with increasing copper concentration up to 125nM and decreased thereafter reaching a minimum value at 1000nM. 13C of Particulate organic carbon varied inversely with increasing copper concentrations indicating the signature of enhanced carbon fixation which is in agreement with the enhanced biomass and growth rate. However, to get a better understanding about the role of copper behind the enhanced growth, we had incubated the cells simultaneously in iron replete, copper replete and in varying copper concentration in presence of 200nM of iron. Surprisingly, in all cases significant enhancement in growth and biomass production was observed. The cells grown in only iron and added with copper showed very similar increase whereas, in presence of iron increasing copper concentration did not show any enhancement effect. Increased growth and biomass production in response to iron addition shows that phytoplankton growth is limited by iron in the study area. Furthermore, this observation indicates that in case of iron limitation the coastal diatom perform a high affinity iron acquisition mechanism where copper plays a vital role. Down regulation of high affinity iron acquisition mechanism was indicated by unaltered growth when copper was added in presence of iron. Collectively, our present study shows that copper likely plays an important role in the physiology of coastal diatom apart from the toxicological studies conducted earlier. A detailed investigation is needed to understand the high affinity iron acquisition mechanism existing in coastal diatom from the study area.

  9. Synthesis and characterization of rare earth doped barium fluoride nanoparticles and derivatized copper phthalocyanine nanoparticles

    Microsoft Academic Search

    Christopher Mark Bender

    1998-01-01

    Nanoparticles of neodymium doped barium fluoride (Nd:BaFsb2) were synthesized for use as the inorganic component of an optical amplifier composite. Microemulsions were used to maintain domain size in the nano-regime (˜100 nm), and decreasing the volume fraction of the aqueous content, while simultaneously increasing the volume fraction of the cosurfactant (methanol), gave a linear relationship between decreasing domain size and

  10. Raman Studies of Yttrium BARIUM(2) (COPPER(1-X) NICKEL(X)(3) OXYGEN(7-DELTA) and (yttrium BARIUM(2) COPPER(3) OXYGEN(7))(M)(PRASEODYMIUM BARIUM(2) COPPER(3) OXYGEN(7))(N) Superlattices

    NASA Astrophysics Data System (ADS)

    Ham, Kyungmin

    Raman measurements on YBa_2(Cu _{1-x}Ni_{x})O_ {7-delta} and (YBa _2Cu_3O_7)_{m}(PrBa _2Cu_3O_7)_{n} superlattices have been performed. The unusual softening of the B_{1g} -like phonon of YBa_2Cu_3O _7 is studied as a function of T _{c} by substituting up to 6 atomic percent nickel for Cu. The abrupt onset and small temperature range over which the softening occurs in undoped YBa_2Cu_3O_7 are modified upon doping with the softening occurring well above T_{c} and continuing smoothly to 10K when T_{ c} is reduced to 71K. The phonon linewidth in the doped films shows no anomalies, regardless of Ni concentration. In contrast, the self-energies of the A_{g} modes associated with the plane copper (Cu(2)) and apical oxygen (O4) atoms reveal normal thermal behavior for all films. We conclude that an additional mechanism, besides strong coupling of phonons to superconducting electrons, contributes to the B_{1g} phonon anomalies in the Ni-doped samples. The Raman spectra from artificial structures of c- and a-axis oriented superlattices (YBa _2Cu_3O_7)_{m}(PrBa _2Cu_3O_7)_{n} with 1 < m, n < 15 are, in general, similar to those obtained from samples of the individual constituents. The observed Raman active vibrations of the superlattice are readily identified through comparison with spectra from the bulk components. The dependence of the phonon frequencies on m and n shows a significant softening of the vibration associated with the apical oxygen atom (O(4)) in PrBa_2Cu_3O _7 with reductions in the Pr-layer thickness (d_{Pr}). The modifications to the self energy of this phonon for both superlattice orientations only occur when d_{Pr} < 25A and therefore establish the primary importance of the Pr-layer thickness in affecting the observed softening. These phonon renormalizations are consistent with charge redistribution in the immediate vicinity (~10A) of the interface arising from the unequal Fermi energies associated with the alternating layers. The degree of inter-diffusion between Pr and Y sites is shown to be negligible with no detectable interfacial alloying. Reminiscent of behavior in bulk YBa_2Cu_3O _7, the out-of-phase O(2)-O(3) phonon confined to Y-layers as small as two unit cells softens below the superconducting transition temperature T_ {c}. The corresponding phonon localized to the Pr layers shows no softening down to n = 1 and therefore suggests the absence of proximity induced superconductivity in the rm PrBa_2Cu _3O_7 layers.

  11. Recovery of iron from copper slag by deep reduction and magnetic beneficiation

    NASA Astrophysics Data System (ADS)

    Li, Ke-qing; Ping, Shuo; Wang, Hong-yu; Ni, Wen

    2013-11-01

    Aiming at recovering iron from high-iron-content copper slag, this article introduced a combination technology of deep reduction and magnetic beneficiation, investigated the iron recovery efficiency and optimized the technical conditions. When coke powder with 86wt% fixed carbon was used as a reductant, iron was successfully extracted from the copper slag. Under the optimized condition of the coke powder content of 14wt%, the calcium-to-silicon mass ratio (Ca/Si) of 0.2, the roasting temperature of 1300°C, the roasting time of 3 h, the grinding time of 20 min, and the magnetic field intensity of 61 kA·m-1, the iron recovery rate of the copper slag can reach 91.82%, and the extracted iron powder has an iron grade of 96.21%. With the characteristics of high iron grade and low impurity content, the extracted iron powder can be used as high-quality raw materials of weathering steel.

  12. Beneficial Effect of Goat Milk on Nutritive Utilization of Iron and Copper in Malabsorption Syndrome

    Microsoft Academic Search

    M. Barrionuevo; M. J. M. Alferez; I. Lopez Aliaga; M. R. Sanz Sampelayo; M. S. Campos

    2002-01-01

    The search for diets that improve the digestive and metabolic use of iron and copper in malabsorption syn- drome led us to study goat milk for particular nutri- tional characteristics and compare it with cow milk, which is usually supplied. We studied the metabolism of iron and copper in transected rats (control) and in resected rats (resection of 50% of

  13. Iron and copper transport in yeast and its relevance to human disease

    Microsoft Academic Search

    Candice Askwith; Jerry Kaplan

    1998-01-01

    Recent progress in the field of copper and iron metabolism has resulted from a convergence of human and yeast genetics. The mechanisms of iron and copper transport are remarkably conserved between yeast and humans. Studies of the yeast homologs of human disease genes involved in metal homeostasis have shed light on the pathophysiology of these disorders.

  14. Hepatic iron overload may contribute to hypertriglyceridemia and hypercholesterolemia in copper-deficient rats.

    PubMed

    Fields, M; Lewis, C G

    1997-04-01

    The present study was conducted in order to determine whether hepatic iron retention in rats fed a copper-deficient diet containing fructose is associated with hypertriglyceridemia and hypercholesterolemia, and whether a reduction of iron intake will prevent elevation of blood triglycerides and cholesterol. Rats were fed from weaning either a copper-deficient (0.6 microgram Cu/g) or copper-adequate (6.0 micrograms Cu/g) diet for 4 weeks. Half the rats consumed either an adequate level of iron (50 micrograms Fe/g) or a low level (17 micrograms Fe/g). Reduction of iron intake reduced blood levels of both triglycerides and cholesterol in rats fed a copper-deficient diet containing fructose. In addition, hepatic lipid peroxidation was also decreased. The combination of high iron, low copper, and fructose may be responsible for increased levels of risk-factor metabolites associated with heart disease. PMID:9109839

  15. Effect of copper and iron on the oxidative flavor deterioration of ice cream 

    E-print Network

    Miah, Md. Abdul Hamid

    1961-01-01

    , . TQliv OF CO?TEKTS IRTRODICTI( R, , . . . , , , , . . . . , . . . ~ Ri'VIEW OF LITERATURE Copper and Iron in FdIR . Oxidised Flavor Defects . 3 3 7 EXFERIV& NTPI WTHCDS ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Souroe of Samples . . Determination cf Copper cnd... Iron Thiobarbituric Acid Test (TRA) preparation oi' Ios Cream Elth and Vithcut Added Copper or Iren, WEanoleptic Examination Determination of Fet in Ioe Cream. . . . . . ~ ~ ~ ~ ~ 15 15 15 18 20 21 21 P ~ EIFERIRE?TAL RFNCLTS...

  16. 77 FR 36980 - Migratory Bird Hunting; Application for Approval of Copper-Clad Iron Shot as Nontoxic for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-20

    ...Hunting; Application for Approval of Copper-Clad Iron Shot as Nontoxic for Waterfowl...applied for our approval of shot composed of copper and iron as nontoxic for waterfowl hunting...shot contains a maximum of 44.1 percent copper by weight, with iron composing the...

  17. Composite nanoplatelets combining soft-magnetic iron oxide with hard-magnetic barium hexaferrite

    NASA Astrophysics Data System (ADS)

    Primc, D.; Makovec, D.

    2015-01-01

    By coupling two different magnetic materials inside a single composite nanoparticle, the shape of the magnetic hysteresis can be engineered to meet the requirements of specific applications. Sandwich-like composite nanoparticles composed of a hard-magnetic Ba-hexaferrite (BaFe12O19) platelet core in between two soft-magnetic spinel iron oxide maghemite (?-Fe2O3) layers were synthesized using a new, simple and inexpensive method based on the co-precipitation of Fe3+/Fe2+ ions in an aqueous suspension of hexaferrite core nanoparticles. The required close control of the supersaturation of the precipitating species was enabled by the controlled release of the Fe3+ ions from the nitrate complex with urea ([Fe((H2N)2C&z.dbd;O)6](NO3)3) and by using Mg(OH)2 as a solid precipitating agent. The platelet Ba-hexaferrite nanoparticles of different sizes were used as the cores. The controlled coating resulted in an exclusively heterogeneous nucleation and the topotactic growth of the spinel layers on both basal surfaces of the larger hexaferrite nanoplatelets. The direct magnetic coupling between the core and the shell resulted in a strong increase of the energy product |BH|max. Ultrafine core nanoparticles reacted with the precipitating species and homogeneous product nanoparticles were formed, which differ in terms of the structure and composition compared to any other compound in the BaO-Fe2O3 system.By coupling two different magnetic materials inside a single composite nanoparticle, the shape of the magnetic hysteresis can be engineered to meet the requirements of specific applications. Sandwich-like composite nanoparticles composed of a hard-magnetic Ba-hexaferrite (BaFe12O19) platelet core in between two soft-magnetic spinel iron oxide maghemite (?-Fe2O3) layers were synthesized using a new, simple and inexpensive method based on the co-precipitation of Fe3+/Fe2+ ions in an aqueous suspension of hexaferrite core nanoparticles. The required close control of the supersaturation of the precipitating species was enabled by the controlled release of the Fe3+ ions from the nitrate complex with urea ([Fe((H2N)2C&z.dbd;O)6](NO3)3) and by using Mg(OH)2 as a solid precipitating agent. The platelet Ba-hexaferrite nanoparticles of different sizes were used as the cores. The controlled coating resulted in an exclusively heterogeneous nucleation and the topotactic growth of the spinel layers on both basal surfaces of the larger hexaferrite nanoplatelets. The direct magnetic coupling between the core and the shell resulted in a strong increase of the energy product |BH|max. Ultrafine core nanoparticles reacted with the precipitating species and homogeneous product nanoparticles were formed, which differ in terms of the structure and composition compared to any other compound in the BaO-Fe2O3 system. Electronic supplementary information (ESI) available: Synthesis (ESI #1) and properties (ESI #2) of the barium hexaferrite core nanoparticles, TEM of the nanoparticles synthesized under an excessive supersaturation (ESI #3), and magnetic properties of physical mixtures of the hard-magnetic hexaferrite and the soft-magnetic spinel ferrite (ESI #4). See DOI: 10.1039/c4nr05854b

  18. Copper tolerance in iron-reducing bacteria: Implications for copper mobilization in sediments

    SciTech Connect

    Markwiese, J.T.; Meyer, J.S.; Colberg, P.J.S. [Univ. of Wyoming, Laramie, WY (United States)

    1998-04-01

    Iron-reducing bacteria enriched from a Cu-contaminated sediment were more tolerant of Cu adsorbed to hydrous ferric oxide (HFO) than were pristine-sediment bacteria. Tolerance was enhanced by increasing the Cu concentration in the culture medium over time, enabling the bacteria to begin reducing Cu-contaminated HFO sooner and at a faster rate than Cu-intolerant bacteria. Copper tolerance confers a greater ability to reduce contaminated HFO and may result in a greater potential for Cu mobilization in sediments.

  19. Mössbauer Evidence for Ferromagnetic Ordering in Copper-Iron Cyanometallates

    NASA Astrophysics Data System (ADS)

    Xia, Yuan-Fu; Yu, Zhi; Song, Yong; Huang, Hong-Bo; You, Xiao-Zeng; Zhou, X. Z.; Li, Z. W.; Kunkel, H. P.; Williams, Gwyn

    2002-04-01

    A novel member of the Prussian blue family, Cu3II[ FeIII(CN)6]2.3NH3.6H2O, was synthesized, in which NH3 ligands are in stochastic distribution. We present x-ray diffraction data, zero-field-cooled magnetization and field-cooled magnetization curves, Mössbauer spectra with/without an external field of 5 T and a structural model. This Prussian blue analogue displays considerable magnetic hardness below the magnetic transition temperature Tc, which is about 19.8 K. The coercive field determined from the magnetization hysteresis loop at 5 K was 2.76 kOe. The copper-iron cyanometallates have potential applications in the design of novel magnetic systems.

  20. Hyperfine Field and Hyperfine Anomalies of Copper Impurities in Iron

    E-print Network

    V. V. Golovko; F. Wauters; S. Cottenier; M. Breitenfeldt; V. De Leebeeck; S. Roccia; G. Soti; M. Tandecki; E. Traykov; S. Van Gorp; D. Zákoucký; N. Severijns

    2011-07-29

    A new value for the hyperfine magnetic field of copper impurities in iron is obtained by combining resonance frequencies from experiments involving {\\beta}-NMR on oriented nuclei on 59-Cu, 69-Cu, and 71-Cu with magnetic moment values from collinear laser spectroscopy measurements on these isotopes. The resulting value, i.e., Bhf(CuFe) = -21.794(10) T, is in agreement with the value adopted until now but is an order of magnitude more precise. It is consistent with predictions from ab initio calculations. Comparing the hyperfine field values obtained for the individual isotopes, the hyperfine anomalies in Fe were determined to be 59{\\Delta}69=0.15(9)% and 71{\\Delta}69=0.07(11)%.

  1. Removal of copper from carbon-saturated steel with an aluminum sulfide/iron sulfide slag

    SciTech Connect

    Cohen, A.; Blander, M.

    1995-12-01

    Scrap iron and steel has long been considered a resource in the steel-making industry, and its value is largely determined by its impurity content. As the mini-mills, the major consumers of scrap iron and steel, expand into producing flat-rolled sheet, the demand for high-quality scrap will increase. Of the impurities present in scrap, copper is particularly troublesome because of its role in causing hot shortness. Therefore, the copper content of scrap should be kept below {approx} 0.1 wt%. A method for removing copper from steel could be used to improve the quality of scrap and make it more available for use by mini-mills. To determine the effectiveness of a binary slag consisting of aluminum sulfide and iron sulfide on the removal of copper from steel and iron, the distribution coefficient of copper between the slag and a carbon-saturated iron melt was investigated at 1,365 C. The composition of the slag was varied from nearly pure aluminum sulfide to pure iron sulfide. A maximum distribution coefficient of 30 was found, and the copper level in the iron melt was reduced to as low as 0.07 wt.% with a 4:1 ratio of iron to slag.

  2. Kinetic lattice Monte Carlo simulations of cascade aging in iron and dilute iron-copper alloys

    SciTech Connect

    Wirth, B.D.; Odette, G.R.

    1999-07-01

    Neutron hardening and embrittlement of pressure vessel steels is due to a high density of nm scale features, including copper-manganese-nickel rich precipitates and what are generally believed to be defect cluster-solute complexes. It has been postulated that the sub nanometer defect cluster-solute complexes form directly in displacement cascades. Cluster-complexes that are thermally unstable mediate the effect of flux on embrittlement kinetics. Larger cluster-complexes, that are relatively thermally stable for irradiation times up to 1 Gs, cause embrittlement in low copper steels. Robust characterization of these two types of so-called matrix defects has been an elusive goal. In this work, Kinetic Lattice Monte Carlo (KLMC) simulations of the long term evolution of the vacancy-rich cascade core regions were carried out for both pure iron and dilute iron-copper alloys at the nominal irradiation temperature of 563 K up to times when the vacancy clusters completely dissolve. Energetics were based on lattice embedded atom method potentials, Special time scaling and pulse annealing techniques were used to deal with the enormous range of inherent time scales involved, viz., rapid free vacancy jumps to slow emission from large complexes. Three-dimensional clusters rapidly form, containing a wide range of vacancies, as well as copper atoms in alloys. Small complexes are very mobile and growth takes place primarily by coalescence. The vacancy clusters ultimately dissolve at times from less than 0.1 to more than 100 MS. These simulations support the hypotheses that cascade cluster-complexes constitute both thermally stable and unstable matrix defect features.

  3. Q factor of dual-tunable microwave resonators based on yttrium iron garnet and barium strontium titanate layered structures

    NASA Astrophysics Data System (ADS)

    Ustinov, A. B.; Kalinikos, B. A.; Tiberkevich, V. S.; Slavin, A. N.; Srinivasan, G.

    2008-03-01

    Q factor of dual-tunable ferrite-ferroelectric hybrid wave microwave resonator was studied as a function of bias electric voltage U and bias magnetic field H. The resonator consisted of a thin (7?m) ferromagnetic resonator made of a single-crystal yttrium iron garnet film and a dielectric resonator made of relatively thick (500?m) plate of ceramic barium strontium titanate having similar in-plane sizes. A frequency spectrum of the resonator consisted of two hybridized modes: a quasiferromagnetic mode and a quasidielectric mode. Maximum electric tuning band of 5% of the resonance frequency has been observed for H values corresponding to maximum hybridization of the modes. The Q factor of the resonator was varied from 30-300 depending on both U and H. In general, Q factor decreases with increasing level of modes' hybridization and electric tuning interval. Thus, Q factor and electric tunability are competing characteristics of hybrid ferrite-ferroelectric microwave resonators.

  4. Copper and Iron are Mobilized Following Myocardial Ischemia: Possible Predictive Criteria for Tissue Injury

    Microsoft Academic Search

    Mordechai Chevion; Yandong Jiang; Ronit Har-El; Eduard Berenshtein; Gideon Uretzky; Nachum Kitrossky

    1993-01-01

    Direct evidence for substantial mobilization of copper in the coronary flow immediately following prolonged, but not short, cardiac ischemia is presented. In the first coronary flow fraction (CFF) of reperfusion (0.15 ml), after 35 min of ischemia, the level of copper (as well as of iron) was 8- to 9-fold higher than the preischemic value. The levels in subsequent CFFs

  5. Crystal structure and related properties of copper-doped barium titanate ceramics

    NASA Astrophysics Data System (ADS)

    Langhammer, Hans Theo; Müller, Thomas; Böttcher, Rolf; Abicht, Hans-Peter

    2003-07-01

    The influence of copper on the crystallographic phase and the microstructure of ceramics with a nominal composition of BaTiO 3+0.02 BaO+ x CuO (0? x?0.02) was investigated. Systematic studies of X-ray diffraction and electron paramagnetic resonance (EPR) with varying doping level and sintering temperature were performed. The EPR data show that Cu 2+ is incorporated into the BaTiO 3 lattice at Ti-sites. Like in the case of other 3d transition elements as, e.g., Mn, Fe or Ni, also Cu decreases the phase transition temperature cubic-hexagonal and stabilizes the hexagonal phase at room temperature. At Cu concentrations ?0.3 mol% and at a sintering temperature of 1400 °C hexagonal phase occurs and the microstructure exhibits exaggerated, plate-like grains with grain sizes ?200 ?m which is typical for hexagonal BaTiO 3 ceramics. Compared to the doping with manganese, copper is more effective to stabilize the hexagonal phase, but its solubility into the BaTiO 3 lattice is significantly lower. Depending on doping level and sintering temperature the EPR data exhibit in the whole temperature range between 40 and 450 K a superposition of two spectra of Cu Ti2+ which are attributed to tetragonally distorted CuO 6 octahedra in a tetragonal and hexagonal crystal surrounding, respectively. Analogous to the case of Ti Ti3+ (d 1), Mn Ti3+ (d 4), Fe Ti2+ (d 6) or Ni Ti3+ (d 7), the Jahn-Teller distortion caused by the d 9 electron configuration of Cu Ti2+ is proposed as the driving force for the phase transition cubic to hexagonal.

  6. Rat brain iron concentration is lower following perinatal copper deficiency

    PubMed Central

    Prohaska, Joseph R.; Gybina, Anna A.

    2009-01-01

    Experiments performed with Holtzman rats demonstrated that brain iron (Fe) was lower by postnatal day 13 (P13) in pups born and nursed by dams that began copper-deficient (?Cu) treatment at embryonic day 7. Transcardial perfusion of P24– P26 males and females to remove blood Fe contamination revealed that brain Fe was still 20% lower in ?Cu than +Cu rats. Estimated blood content of brain for ?Cu rats was greater than for +Cu rats; for all groups, values ranged between 0.43 and 1.03%. Using group-specific data and regression analyses, r = 0.99, relating blood Fe to hemoglobin, brain Fe in non-perfused rats in a replicate study was lower by 33% at P13 and 39% at P24 in ?Cu rats. Brain extracts from these rats and from P50 rats from a post-weaning model were compared by immunobloting for transferrin receptor (TfR1). P24 brain ?Cu/+Cu TfR1 was 3.08, suggesting that brains of ?Cu rats were indeed Fe deficient. This ratio in P13 rats was 1.44, p < 0.05. No change in P50 ?Cu rat brain TfR1 or Fe content was detected despite a 50% reduction in plasma Fe. The results suggest that brain Fe accumulation depends on adequate Cu nutriture during perinatal development. PMID:15836628

  7. Iron, Manganese and Copper Release from Synthetic Hydroxyapatite

    NASA Technical Reports Server (NTRS)

    Sutter, B.; Hossner, L. R.; Ming, Douglas W.

    1999-01-01

    Kinetic stir-flow dissolution experiments were performed on iron- (Fe-SHA), manganese- (Mn-SHA), and copper- (Cu-SHA) containing synthetic hydroxyapatites. Solution treatments consisted of de-ionized water, citric acid and DTPA. Initially, Mn concentrations were higher than Cu concentrations and Fe concentrations were the lowest in all treatments. At later times Mn and Cu concentrations dropped in the DTPA treatment while Fe rose to the concentration similar to Mn and Cu. At all times, metal release concentrations in the water and citric acid treatments followed the trend of Mn>Cu>Fe. Rietveld analysis of x-ray diffraction data and ^31P NMR indicated that the metals substituted for Ca in the SHA structure. However, EPR data suggested that a metal (hydr)oxide phase existed either on the SHA surface or between the SHA crystallites. The metal concentration trend of Mn>Cu>Fe suggested that the initial solution metal concentrations are dependent on the dissolution of (hydr)oxides from SHA surfaces or between SHA crystallites. Similar metal concentrations at later times in the DTPA experiments suggests that metal concentrations were controlled by the release of Mn, Cu, or Fe from the SHA structure.

  8. Iron and copper as virulence modulators in human fungal pathogens.

    PubMed

    Ding, Chen; Festa, Richard A; Sun, Tian-Shu; Wang, Zhan-You

    2014-07-01

    Fungal pathogens have evolved sophisticated machinery to precisely balance the fine line between acquiring essential metals and defending against metal toxicity. Iron and copper are essential metals for many processes in both fungal pathogens and their mammalian hosts, but reduce viability when present in excess. However, during infection, the host uses these two metals differently. Fe has a long-standing history of influencing virulence in pathogenic fungi, mostly in regards to Fe acquisition. Numerous studies demonstrate the requirement of the Fe acquisition pathway of Candida, Cryptococcus and Aspergillus for successful systemic infection. Fe is not free in the host, but is associated with Fe-binding proteins, leading fungi to develop mechanisms to interact with and to acquire Fe from these Fe-bound proteins. Cu is also essential for cell growth and development. Essential Cu-binding proteins include Fe transporters, superoxide dismutase (SOD) and cytochrome c oxidase. Although Cu acquisition plays critical roles in fungal survival in the host, recent work has revealed that Cu detoxification is extremely important. Here, we review fungal responses to altered metal conditions presented by the host, contrast the roles of Fe and Cu during infection, and outline the critical roles of fungal metal homeostasis machinery at the host-pathogen axis. PMID:24851950

  9. Impairment of Interrelated Iron- and Copper Homeostatic Mechanisms in Brain Contributes to the Pathogenesis of Neurodegenerative Disorders

    PubMed Central

    Skjørringe, Tina; Møller, Lisbeth Birk; Moos, Torben

    2012-01-01

    Iron and copper are important co-factors for a number of enzymes in the brain, including enzymes involved in neurotransmitter synthesis and myelin formation. Both shortage and an excess of iron or copper will affect the brain. The transport of iron and copper into the brain from the circulation is strictly regulated, and concordantly protective barriers, i.e., the blood-brain barrier (BBB) and the blood-cerebrospinal fluid (CSF) barrier (BCB) have evolved to separate the brain environment from the circulation. The uptake mechanisms of the two metals interact. Both iron deficiency and overload lead to altered copper homeostasis in the brain. Similarly, changes in dietary copper affect the brain iron homeostasis. Moreover, the uptake routes of iron and copper overlap each other which affect the interplay between the concentrations of the two metals in the brain. The divalent metal transporter-1 (DMT1) is involved in the uptake of both iron and copper. Furthermore, copper is an essential co-factor in numerous proteins that are vital for iron homeostasis and affects the binding of iron-response proteins to iron-response elements in the mRNA of the transferrin receptor, DMT1, and ferroportin, all highly involved in iron transport. Iron and copper are mainly taken up at the BBB, but the BCB also plays a vital role in the homeostasis of the two metals, in terms of sequestering, uptake, and efflux of iron and copper from the brain. Inside the brain, iron and copper are taken up by neurons and glia cells that express various transporters. PMID:23055972

  10. Biochemical Evolution of Iron and Copper Proteins, Substances Vital to Life

    ERIC Educational Resources Information Center

    Frieden, Earl

    1974-01-01

    Summarizes studies in the area of biochemical evolution of iron, copper, and heme proteins to provide an historical outline. Included are lists of major kinds of proteins and enzymes and charts illustrating electron flow in a cytochrome electron transport system and interconversion of jerrous to ferric ion in iron metabolism. (CC)

  11. Flux Pinning Phenomena in Electron Irradiated Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA) Single Crystals

    NASA Astrophysics Data System (ADS)

    Giapintzakis, John Konstantinos

    1992-01-01

    It has been shown that 1 MeV electron irradiation to a typical dose Phi~ 1times 10^{19} cm^{ -2} results in an enhancement of the critical current density in twinned and untwinned YBa_2 Cu_3O_{7 -delta} single crystals. Values up to two times the preirradiation J_{c} at 10 K and 1 T are observed. The J _{c} enhancement is accompanied by a dramatic increase of the irreversibility field. A threshold incident electron energy (E_{ t}~ 0.5 MeV) is found above which flux pinning enhancement is observed. The data indicated that the electron radiation-induced defects are effective pinning centers only for the orientation H parallel c-axis. In-situ TEM studies in the HVEM suggest that the pinning centers must be smaller than 20 A. A comparison of the electron irradiation results with those of proton irradiation experiments indicate a lower magnitude of enhancement of J_{c} at 10 K and 2 T for the electron case. The probable explanation is the difference in the energy spectra of the PKAs produced by the two types of irradiation. GdBa_2Cu_3O_{7-delta } and EuBa_2Cu_3O _{7-delta} single crystals irradiated with 0.6 MeV electrons displayed similar flux pinning enhancements as YBa_2Cu _3O_{7-delta} crystals, indicating that Y displacements are not primary flux pinners. The evidence from annealing studies suggests that the primary pinning center produced by the electron irradiation is not associated with the oxygen in the Cu-O chains. Instead, a consistent interpretation of the data suggests that the primary pinning defect is most likely based on the displacement of a copper atom from the CuO_2 plane. In order to account for the complete enhancement of J_{c} other pinning mechanisms aside from point defects, such as small point defect clusters, should be considered.

  12. Bovine hemoglobin as the sole source of dietary iron does not support adequate iron status in copper-adequate or copper-deficient rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This experiment was designed to determine whether hemoglobin as the sole source of dietary iron (Fe) could sustain normal Fe status in growing rats. Because adequate copper (Cu) status is required for efficient Fe absorption in the rat, we also determined the effects of Cu deficiency on Fe status of...

  13. IN-HOUSE CORROSION RESEARCH EMPHASIZING LEAD, COPPER AND IRON

    EPA Science Inventory

    Lead and copper are directly regulated via the "Lead and Copper Rule;" however, water suppliers must balance all water treatment processes in order to simultaneously comply with all regulations. Specific research needs for copper and lead chemistry still exist, as applications o...

  14. An experimental study for enhancing the catalytic effects of various copper forms on the oxidation of ferrous iron.

    PubMed

    Babak, Manizhe Moradi Shahre; Goharrizi, Ataallah Soltani; Mirzaei, Mohammad; Roayaei, Emad

    2013-01-01

    In this research the catalytic effect of copper compounds (ionic, oxide and oxide nanopowder) on the oxidation of ferrous iron by aeration was studied experimentally. When copper exists in solution, the oxidation rate of iron(II) will increase. The experimental results showed that the oxidation rate increases with an increasing copper concentration. From the experimental data it can be determined that the copper oxide nanopowder is the most effective for the oxidation reaction among the used copper forms. Aeration is the most economical oxidation method when water exhibits a high ferrous iron concentration. PMID:23530309

  15. Evolution of Microstructures During Austempering of Ductile Irons Alloyed with Manganese and Copper

    NASA Astrophysics Data System (ADS)

    Dasgupta, Ranjan Kumar; Mondal, Dipak Kumar; Chakrabarti, Ajit Kumar

    2013-03-01

    The influences of relatively high manganese (0.45 through 1.0 wt pct) and copper (0.56 through 1.13 wt pct) contents on microstructure development and phase transformation in three austempered ductile irons have been studied. The experimental ductile irons alloyed with copper and manganese are found to be practically free from intercellular manganese segregation. This suggests that the positive segregation of manganese is largely neutralized by the negative segregation of copper when these alloying elements are added in appropriate proportions. The drop in unreacted austenite volume (UAV) with increasing austempering temperature and time is quite significant in irons alloyed with copper and manganese. The ausferrite morphology also undergoes a transition from lenticular to feathery appearance of increasing coarseness with the increasing austempering temperature and time. SEM micrographs of the austempered samples from the base alloy containing manganese only, as well as copper plus manganese-alloyed irons, clearly reveal the presence of some martensite along with retained austenite and ferrite. X-ray diffraction analysis also confirms the presence of these phases. SEM examination further reveals the presence of twinned martensite in the copper plus manganese-alloyed samples. The possibility of strain-induced transformation of austenite to martensite during austempering heat treatment is suggested.

  16. Urinary excretion of copper, zinc and iron with and without D-penicillamine administration in relation to hepatic copper concentration in dogs.

    PubMed

    Fieten, H; Hugen, S; van den Ingh, T S G A M; Hendriks, W H; Vernooij, J C M; Bode, P; Watson, A L; Leegwater, P A J; Rothuizen, J

    2013-08-01

    Hereditary copper-associated hepatitis in dogs resembles Wilson's disease, a copper storage disease in humans. Values for urinary copper excretion are well established in the diagnostic protocol of Wilson's disease, whereas in dogs these have not been evaluated. The objectives of this study were to characterize both basal and D-penicillamine induced urinary copper, zinc and iron excretion in dogs in relation to hepatic copper concentration. Beagles, Beagle-Bedlington terrier cross-breeds homozygous for the COMMD1 gene mutation that causes copper toxicosis, and Labrador retrievers with normal or increased hepatic copper concentrations were investigated. The hepatic copper phenotype was determined by histological evaluation of liver biopsies and measurement of the hepatic copper concentration by instrumental neutron activation analysis. Urinary excretion of copper, iron and zinc was measured via inductively coupled plasma optical emission spectrometry under basal conditions and after oral administration of a single dose (20mg/kg bodyweight) of the chelator D-penicillamine. There was a rapid increase in urinary excretion of copper and zinc, but not iron after D-penicillamine administration. This increase was not different between dogs with high or normal hepatic copper concentrations. D-penicillamine-induced urinary copper excretion and the copper/creatinine ratio did not correlate with hepatic copper concentrations in the dogs studied, although basal urinary copper/zinc ratios did correlate with hepatic copper concentrations in Labrador retrievers. The latter parameter may be useful in diagnostic and follow-up protocols for copper-associated hepatitis in Labrador retrievers. PMID:23583003

  17. The iron-sulfur clusters of dehydratases are primary intracellular targets of copper toxicity

    PubMed Central

    Macomber, Lee; Imlay, James A.

    2009-01-01

    Excess copper is poisonous to all forms of life, and copper overloading is responsible for several human pathologic processes. The primary mechanisms of toxicity are unknown. In this study, mutants of Escherichia coli that lack copper homeostatic systems (copA cueO cus) were used to identify intracellular targets and to test the hypothesis that toxicity involves the action of reactive oxygen species. Low micromolar levels of copper were sufficient to inhibit the growth of both WT and mutant strains. The addition of branched-chain amino acids restored growth, indicating that copper blocks their biosynthesis. Indeed, copper treatment rapidly inactivated isopropylmalate dehydratase, an iron-sulfur cluster enzyme in this pathway. Other enzymes in this iron-sulfur dehydratase family were similarly affected. Inactivation did not require oxygen, in vivo or with purified enzyme. Damage occurred concomitant with the displacement of iron atoms from the solvent-exposed cluster, suggesting that Cu(I) damages these proteins by liganding to the coordinating sulfur atoms. Copper efflux by dedicated export systems, chelation by glutathione, and cluster repair by assembly systems all enhance the resistance of cells to this metal. PMID:19416816

  18. Iron and copper in progressive demyelination - New lessons from Skogholt's disease.

    PubMed

    Aspli, Klaus Thanke; Flaten, Trond Peder; Roos, Per M; Holmøy, Trygve; Skogholt, Jon H; Aaseth, Jan

    2015-07-01

    The pathophysiological mechanisms of progressive demyelinating disorders including multiple sclerosis are incompletely understood. Increasing evidence indicates a role for trace metals in the progression of several neurodegenerative disorders. The study of Skogholt disease, a recently discovered demyelinating disease affecting both the central and peripheral nervous system, might shed some light on the mechanisms underlying demyelination. Cerebrospinal fluid iron and copper concentrations are about four times higher in Skogholt patients than in controls. The transit into cerebrospinal fluid of these elements from blood probably occurs in protein bound form. We hypothesize that exchangeable fractions of iron and copper are further transferred from cerebrospinal fluid into myelin, thereby contributing to the pathogenesis of demyelination. Free or weakly bound iron and copper ions may exert their toxic action on myelin by catalyzing production of oxygen radicals. Similarities to demyelinating processes in multiple sclerosis and other myelinopathies are discussed. PMID:25563774

  19. Chronic administration of iron and copper potentiates adipogenic effect of high fat diet in Wistar rats.

    PubMed

    Tinkov, Alexey A; Polyakova, Valentina S; Nikonorov, Alexandr A

    2013-06-01

    The primary objective of this research project is explore a possible adipogenic effect of iron and/or copper in albino Wistar rats kept on standard (STD) and high-fat (HFD) diets. The female Wistar rats in the study were divided into eight experimental groups (n = 6). Rats maintained on STD and HFD received 3 mg/l FeSO??7H?O, 4.88 mg/l CuSO? and a combination of 1.5 mg/l FeSO??7H?O and 2.44 mg/l CuSO? with drinking water. Control groups were kept on STD and HFD and received pure water without metal salts. Consumption of iron and copper in the groups of rats maintained on an STD did not produce a significant increase in weight, adipose tissue content or body mass index. However, the adipocyte size and infiltration were increased in the adipose tissue of STD-fed rats receiving a mixture of iron and copper with drinking water. The rats fed iron and copper and, especially, their combination on a HFD background had a significantly higher weight gain, adipose tissue content, morphometric parameters values and adipocyte size compared to STD- and HFD-fed controls. Iron and copper consumption produced their accumulation in the rats' adipose tissue. Moreover, the studied metals reduced adipose tissue concentration of chromium and vanadium. The lipoprotein profile and serum oxidative stress biomarkers were affected in the rats receiving the metals and STD. Hyperglycemia was observed in the rats receiving the studied metals on HFD-background. Based on the analysis of the test subjects, the study suggests that iron and copper administration, especially combined, may potentiate adipogenic effect of HFD. PMID:23657865

  20. 77 FR 59158 - Migratory Bird Hunting; Application for Approval of Copper-Clad Iron Shot and Fluoropolymer Shot...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-26

    ...51.1 tungsten, 44.4 copper, Rare Earth Magnet. 3.9 tin, and 0.6 iron...10-37 iron, Hot Shot[supreg] or Rare Earth Magnet. 9-16 copper, and 5-7...any proportions of Rare Earth Magnet. tungsten, tin, and...

  1. Copper, iron, and zinc interactions with chlorophyll in extracts of photosynthetic pigments studied by VIS spectroscopy

    NASA Astrophysics Data System (ADS)

    Zvezdanovi?, J.; Markovi?, D.

    2009-09-01

    Interactions of copper, iron and zinc with chlorophyll, the major photosynthesis pigment, were studied by VIS spectrophotometry in extracts of photosynthetic pigments (in vitro). Copper predominantly forms Cu-Chl complexes in all studied systems (Cu-, Cu/Fe-, Cu/Zn- and Cu/Fe/Zn-incubated pigment solutions). It is not clear whether iron forms Fe-Chl complexes or produces pheophytin. It’s effect is dominant over zinc (Fe/Zn-system) but highly minor compared to Cu-effect when all three metals are present (Cu/Fe/Zn-Chl system) in the same concentrations.

  2. Integration of nonlinear dielectric barium strontium titanate with polycrystalline yttrium iron garnet

    NASA Astrophysics Data System (ADS)

    Jia, Q. X.; Groves, J. R.; Arendt, P.; Fan, Y.; Findikoglu, A. T.; Foltyn, S. R.; Jiang, H.; Miranda, F. A.

    1999-03-01

    Biaxially oriented nonlinear dielectric Ba0.6Sr0.4TiO3 (BST) films have been grown on polycrystalline ferrite yttrium iron garnet (YIG) substrates. We use a structurally and chemically compatible MgO buffer to improve the crystallinity of the BST on polycrystalline YIG substrates, where the biaxially oriented MgO is deposited by an ion-beam assisted-deposition technique. The biaxially oriented BST has a dielectric loss of less than 0.01 and a capacitance tunability of greater than 25% at a direct current bias voltage of 40 V at room temperature.

  3. Hepatic zinc, copper, and iron in the developing turkey embryo and newly hatched poult.

    PubMed

    Richards, M P; Weinland, B T

    1985-06-01

    The ontogeny of hepatic tissue growth and trace metal deposition was examined in the developing turkey embryo and newly hatched poult. Hepatic concentrations of zinc and iron in the embryo declined by about twofold between day 16 of incubation and hatching. Hepatic copper concentration increased approximately fourfold by day 23 of incubation and then declined rapidly through hatching. During the post-hatching period, hepatic zinc concentration increased twofold by day 10, whereas a small increase in hepatic iron concentration occurred just prior to hatching and continued through the third day post-hatching. A significant positive correlation existed between hepatic zinc and iron concentrations in the developing embryo. The concentrations of both these metals were inversely correlated with hepatic copper concentration during the same time. Total hepatic zinc and iron content increased throughout the entire time studied, whereas total copper content increased up to hatching and then declined during the first week post-hatching. The most rapid phase of hepatic metal accretion differed for each metal, with zinc being rapidly accumulated during the post-hatching period, copper during the last half of incubation and iron at about the time of hatching and the first few days post-hatching. Each of these metals demonstrated a specific relationship to hepatic tissue growth that changed between the embryonic and neonatal periods of development. PMID:24259162

  4. Simultaneous third-derivative spectrophotometric determination of copper and nickel in iron alloys and aluminium alloy.

    PubMed

    Wang, N; Liang, W; Qi, P

    1993-06-01

    A method is proposed for the simultaneous determination of copper and nickel by third-derivative spectrophotometry based on the absorption spectra of their complexes with cyanide ion in the ultraviolet range. The method allows the determination of 0.55-5.8 mug/ml of copper and 0.55-6.8 mug/ml of nickel. The relative standard deviation for 11 determinations of 1.5 mul/ml of copper and nickel were 0.78 and 0.72%, respectively. The detection limits were 0.10,mug/ml for nickel and 0.13 mug/ml for copper. The method has been applied to direct determination of copper and nickel in iron alloys and an aluminium alloy without any separation. PMID:18965724

  5. Effect of hydrothermal synthesis environment on the particle morphology, chemistry and magnetic properties of barium hexaferrite

    Microsoft Academic Search

    A. Ataie; M. R. Piramoon; I. R. Harris; C. B. Ponton

    1995-01-01

    Barium nitrate and iron nitrate have been used as precursors in the hydrothermal synthesis of barium hydroxide, iron oxide and barium hexaferrite sols under specified standard synthesis conditions (temperature, time, stirring, alkali concentration, amount of water and heating rate) as a function of the base species used during synthesis. The hydrothermal synthesis of barium hydroxide and iron oxide has been

  6. Inhibitory effect of ethanolamine plasmalogen on iron- and copper-dependent lipid peroxidation

    Microsoft Academic Search

    Mohsen Zommara; Nobuhiko Tachibana; Kosuke Mitsui; Noriaki Nakatani; Masanobu Sakono; Ikuo Ikeda; Katsumi Imaizumi

    1995-01-01

    The effect of ethanolamine plasmalogen (EtnPm) on lipid peroxidation was investigated in liposomal suspension of egg yolk phosphatidylcholine. EtnPm inhibited iron- and copper-dependent peroxidation in the presence of preformed hydroperoxides, although it was not effective for radical initiator mediated lipid peroxidation. EtnPm resulted in complete binding of iron to liposomal lipids, suggesting that EtnPm exerts its inhibitory effect on lipid

  7. Lenticular nucleus hyperechogenicity in Wilson's disease reflects local copper, but not iron accumulation.

    PubMed

    Walter, Uwe; Skowro?ska, Marta; Litwin, Tomasz; Szpak, Gra?yna Maria; Jab?onka-Salach, Katarzyna; Skoloudík, David; Bulska, Ewa; Cz?onkowska, Anna

    2014-10-01

    In patients with Wilson's disease (WD) transcranial brain sonography typically reveals areas of increased echogenicity (hyperechogenicity) of the lenticular nucleus (LN). Correlation with T2-hypointensity on magnetic resonance images suggested that LN hyperechogenicity in WD is caused by trace metal accumulation. Accumulation of both, copper and iron, in the brain of WD patients has been reported. The present study was designed to elucidate whether LN hyperechogenicity in WD reflects accumulation of copper or iron. Post-mortem brains of 15 WD patients and one non-WD subject were studied with ultrasonography in an investigator-blinded fashion. LN hyperechogenicity was measured planimetrically by manual tracing as well as using digitized image analysis. The putaminal copper content was determined in samples of 11 WD brains and the non-WD brains using inductively coupled plasma mass spectrometry, and iron content was assessed using flame atomic absorption spectroscopy. LN was normal on ultrasonography only in the non-WD brain, but abnormal (hyperechogenic) in all WD brains. Digitized image analysis measures of LN hyperechogenicity and, by trend, manual measures correlated with putaminal copper content (Pearson test; digitized: r = 0.77, p = 0.04; manual: r = 0.57, p = 0.051) but not with iron content (each, p > 0.18). LN hyperechogenicity measures were unrelated to age at death of patients, age at onset of WD, WD duration, age of brain specimen, serum copper or serum ceruloplasmin (each, p > 0.1). We conclude that LN hyperechogenicity in WD reflects copper, but not iron accumulation. Further studies are warranted to elucidate the use of transcranial brain sonography for monitoring therapeutic effects of chelating agents in WD patients. PMID:24615184

  8. Integration of nonlinear dielectric barium strontium titanate with polycrystalline yttrium iron garnet

    SciTech Connect

    Jia, Q.X.; Groves, J.R.; Arendt, P.; Fan, Y.; Findikoglu, A.T.; Foltyn, S.R. [Superconductivity Technology Center, Mail Stop K763, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Superconductivity Technology Center, Mail Stop K763, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Jiang, H. [NZ Applied Technologies, 150-C New Boston Street, Woburn, Massachusetts 01801 (United States)] [NZ Applied Technologies, 150-C New Boston Street, Woburn, Massachusetts 01801 (United States); Miranda, F.A. [NASA Lewis Research Center, 21000 Brookpark Road, MS 54-5, Cleveland, Ohio 44135 (United States)] [NASA Lewis Research Center, 21000 Brookpark Road, MS 54-5, Cleveland, Ohio 44135 (United States)

    1999-03-01

    Biaxially oriented nonlinear dielectric Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} (BST) films have been grown on polycrystalline ferrite yttrium iron garnet (YIG) substrates. We use a structurally and chemically compatible MgO buffer to improve the crystallinity of the BST on polycrystalline YIG substrates, where the biaxially oriented MgO is deposited by an ion-beam assisted-deposition technique. The biaxially oriented BST has a dielectric loss of less than 0.01 and a capacitance tunability of greater than 25{percent} at a direct current bias voltage of 40 V at room temperature. {copyright} {ital 1999 American Institute of Physics.}

  9. Iron and copper accumulation in the brain of coxsackievirus-infected mice exposed to cadmium

    Microsoft Academic Search

    N.-G.. Ilbaeck; U. Lindh; R. Minqin; G. Friman; F. Watt

    2006-01-01

    Cadmium (Cd) is a potentially toxic metal widely distributed in the environment and known to cause adverse health effects in humans. During coxsackievirus infection, the concentrations of essential and nonessential trace elements (e.g., iron (Fe), copper (Cu), and Cd) change in different target organs of the infection. Fe and Cu are recognized cofactors in host defence reactions, and Fe is

  10. THE ELECTROCHEMICAL SYNTHESIS OF ETHYLXANTHATE AND DIMETHYLDITHIOCARBAMATE COMPLEXES OF IRON, COBALT, NICKEL AND COPPER

    Microsoft Academic Search

    Allan T. Casey; Angelica M. Vecchio

    1988-01-01

    An electrochemical synthetic method has been developed to effect the one-step preparation of transition metal xanthates and dithiocarbamates by oxidation of the metal in an acetone solution of ethyl dixanthogen or tetramethylthiuram disulphide. Results are presented for O-ethylxanthate and N,N?-dimethyldithio-carbamate complexes of iron(III), cobalt(III), nickel(II) and copper(I, II).

  11. Metal passivity as mechanism of metal carcinogenesis: Chromium, nickel, iron, copper, cobalt, platinum, molybdenum

    Microsoft Academic Search

    Cornelia Richardson-Boedler

    2007-01-01

    For the transition metals chromium, nickel, iron, copper, cobalt, platinum, and molybdenum, mechanisms of stable bonding in biochemistry (emphasis on carcinogenic mechanisms), chemistry, industrial chemistry, as well as epidemiological, occupational, orthopedic (implant devices) effects related to carcinogenesis, were reviewed. Hypothetically, the propensity to stable bonding (inertness), which ensures the metals’ performance capacity for consumers and industrial application, relates to their

  12. Numerical simulation of plastic collapse of copper-cast iron canister for spent nuclear fuel

    Microsoft Academic Search

    Oliver Martin; Karl-Fredrik Nilsson; Nikola Jakši?

    2009-01-01

    This paper describes a finite element simulation of a spent fuel canister for geological disposal loaded in iso-static pressure until plastic collapse. The canister consists of a copper overpack and a ductile cast iron insert with steel cassettes where the spent fuel is placed. The highly non-linear finite element analysis is based on the explicit formulation and includes large deformations,

  13. Iron(II) and Copper(I) Coordination Polymers: Electrochromic Materials with and without Chiroptical Properties

    E-print Network

    Bernhard, Stefan

    Iron(II) and Copper(I) Coordination Polymers: Electrochromic Materials with and without Chiroptical of deterioration over 150 switching cycles. Additionally, in an effort to assemble an electrochromic device with chiroptical properties, the electrochromism of films generated from the enantiomerically pure CTPCT[FeII CTPCT

  14. Microelectrodes Based investigation of the Impacts of Water Chemistry on Copper and Iron Corrosion

    EPA Science Inventory

    The effect of bulk drinking water quality on copper and iron pipe corrosion has been extensively studied. Despite past research, many have argued that bulk water quality does not necessarily reflect water quality near the water-metal interface and that such knowledge is necessary...

  15. Oxidative stress-mediated hepatotoxicity of iron and copper: Role of Kupffer cells

    Microsoft Academic Search

    Luis A. Videla; Virginia Fernández; Gladys Tapia; Patricia Varela

    2003-01-01

    Iron- or copper-mediated catalysis leads to the generation of reactive oxygen species (ROS) that can attack biomolecules directly, with the consequent enhancement in membrane lipid peroxidation, DNA damage, and protein oxidation. Reactive nitrogen species (RNS) can also be formed, leading to nitration of aromatic structures in addition to the oxidative deterioration of cellular components. Kupffer cells, the resident macrophages of

  16. Influence of vegetative cycle of asparagus ( Asparagus officinalis L.) on copper, iron, zinc and manganese content

    Microsoft Academic Search

    M. A. Amaro-Lopez; G. Zurera-Cosano; R. Moreno-Rojas; R. M. Garcia-Gimeno

    1995-01-01

    The essential elements copper (Cu), iron (Fe), zinc (Zn) and manganese (Mn) were analyzed in fresh asparagus to determine the effects of the vegetative cycle of the plant on the micronutrient content. Asparagus samples were classified in two groups by diameter (14 mm). Asparagus from a sample group with the same diameter were divided into two portions (apical and basal)

  17. Composite nanoplatelets combining soft-magnetic iron oxide with hard-magnetic barium hexaferrite.

    PubMed

    Primc, D; Makovec, D

    2015-02-14

    By coupling two different magnetic materials inside a single composite nanoparticle, the shape of the magnetic hysteresis can be engineered to meet the requirements of specific applications. Sandwich-like composite nanoparticles composed of a hard-magnetic Ba-hexaferrite (BaFe12O19) platelet core in between two soft-magnetic spinel iron oxide maghemite (?-Fe2O3) layers were synthesized using a new, simple and inexpensive method based on the co-precipitation of Fe(3+)/Fe(2+) ions in an aqueous suspension of hexaferrite core nanoparticles. The required close control of the supersaturation of the precipitating species was enabled by the controlled release of the Fe(3+) ions from the nitrate complex with urea ([Fe((H2N)2C=O)6](NO3)3) and by using Mg(OH)2 as a solid precipitating agent. The platelet Ba-hexaferrite nanoparticles of different sizes were used as the cores. The controlled coating resulted in an exclusively heterogeneous nucleation and the topotactic growth of the spinel layers on both basal surfaces of the larger hexaferrite nanoplatelets. The direct magnetic coupling between the core and the shell resulted in a strong increase of the energy product |BH|max. Ultrafine core nanoparticles reacted with the precipitating species and homogeneous product nanoparticles were formed, which differ in terms of the structure and composition compared to any other compound in the BaO-Fe2O3 system. PMID:25583312

  18. Electric field tunable 60 GHz ferromagnetic resonance response in barium ferrite-barium strontium titanate multiferroic heterostructures

    E-print Network

    Patton, Carl

    Electric field tunable 60 GHz ferromagnetic resonance response in barium ferrite-barium strontium barium strontium titanate films on Nb-doped strontium titanate substrates were capped with an unbonded comprised of a nominal 7 m thick yttrium iron garnet YIG film in contact with a 500 m thick barium strontium

  19. MD description of damage production in displacement cascades in copper and ?-iron

    NASA Astrophysics Data System (ADS)

    Bacon, D. J.; Osetsky, Yu. N.; Stoller, R.; Voskoboinikov, R. E.

    2003-12-01

    Molecular dynamics computer simulation was applied for an extensive study of primary damage creation in displacement cascades in copper and ?-iron. Primary knock-on atom energy, Ep, of up to 25 keV in copper and 100 keV in iron was considered for irradiation temperatures in the range 100-900 K. Special attention was paid to comprehensive statistical treatment of the number and type of defects created in cascades by conducting multiple simulations for each value of energy and temperature. The total number of point defects per cascade is significantly lower than that predicted by the NRT model and rather similar in the two metals. The fraction of self-interstitial atoms (SIAs) and vacancies that agglomerate in clusters in the cascade process was analysed in detail. The clustered fraction of SIAs increases with temperature increase and is larger in copper than iron. SIA clusters have a variety of forms in both metals and, although most are glissile clusters of parallel crowdions, a significant fraction are sessile. The latter include Frank dislocation loops in copper. Tightly packed arrangements of vacancies do not form in iron, and so the fraction of clustered vacancies depends strongly on the range within which point defects are defined to be near-neighbours. Arrangements of vacancies in first-neighbour sites are common in copper. Most are irregular stacking fault tetrahedra (SFTs). In 53 simulations of cascades with Ep=25 keV at 100 K, the largest cluster formed contained 89 vacancies. The size spectrum of SFT-like clusters is similar to that found experimentally in neutron-irradiated copper, suggesting that the SFTs observed in experiment are formed directly in the cascade process.

  20. MD description of damage production in displacement cascades in copper and ?-iron.

    SciTech Connect

    Bacon, David J [University of Liverpool; Osetskiy, Yury N [ORNL; Stoller, Roger E [ORNL; Voskoboinikov, Roman E [University of Liverpool

    2003-01-01

    Molecular dynamics computer simulation was applied for an extensive study of primary damage creation in displacement cascades in copper and {alpha}-iron. Primary knock-on atom energy, E{sub p}, of up to 25 keV in copper and 100 keV in iron was considered for irradiation temperatures in the range 100-900 K. Special attention was paid to comprehensive statistical treatment of the number and type of defects created in cascades by conducting multiple simulations for each value of energy and temperature. The total number of point defects per cascade is significantly lower than that predicted by the NRT model and rather similar in the two metals. The fraction of self-interstitial atoms (SIAs) and vacancies that agglomerate in clusters in the cascade process was analysed in detail. The clustered fraction of SIAs increases with temperature increase and is larger in copper than iron. SIA clusters have a variety of forms in both metals and, although most are glissile clusters of parallel crowdions, a significant fraction are sessile. The latter include Frank dislocation loops in copper. Tightly packed arrangements of vacancies do not form in iron, and so the fraction of clustered vacancies depends strongly on the range within which point defects are defined to be near-neighbours. Arrangements of vacancies in first-neighbour sites are common in copper. Most are irregular stacking fault tetrahedra (SFTs). In 53 simulations of cascades with E{sub p} = 25 keV at 100 K, the largest cluster formed contained 89 vacancies. The size spectrum of SFT-like clusters is similar to that found experimentally in neutron-irradiated copper, suggesting that the SFTs observed in experiment are formed directly in the cascade process.

  1. Zinc Pyrithione Inhibits Yeast Growth through Copper Influx and Inactivation of Iron-Sulfur Proteins?†

    PubMed Central

    Reeder, Nancy L.; Kaplan, Jerry; Xu, Jun; Youngquist, R. Scott; Wallace, Jared; Hu, Ping; Juhlin, Kenton D.; Schwartz, James R.; Grant, Raymond A.; Fieno, Angela; Nemeth, Suzanne; Reichling, Tim; Tiesman, Jay P.; Mills, Tim; Steinke, Mark; Wang, Shuo L.; Saunders, Charles W.

    2011-01-01

    Zinc pyrithione (ZPT) is an antimicrobial material with widespread use in antidandruff shampoos and antifouling paints. Despite decades of commercial use, there is little understanding of its antimicrobial mechanism of action. We used a combination of genome-wide approaches (yeast deletion mutants and microarrays) and traditional methods (gene constructs and atomic emission) to characterize the activity of ZPT against a model yeast, Saccharomyces cerevisiae. ZPT acts through an increase in cellular copper levels that leads to loss of activity of iron-sulfur cluster-containing proteins. ZPT was also found to mediate growth inhibition through an increase in copper in the scalp fungus Malassezia globosa. A model is presented in which pyrithione acts as a copper ionophore, enabling copper to enter cells and distribute across intracellular membranes. This is the first report of a metal-ligand complex that inhibits fungal growth by increasing the cellular level of a different metal. PMID:21947398

  2. Precipitation of copper in iron under swift ion irradiations

    NASA Astrophysics Data System (ADS)

    Barbu, A.; Pareige, P.; Jacquet, V.

    1998-12-01

    After irradiation was carried out on the Fe1.34 at% Cu supersaturated solution with 2.5 MeV electrons and 188 MeV oxygen ions at 290°C, we report new results about copper precipitation under 5.07 GeV krypton irradiation. The precipitation observed on line by electrical resistivity and after irradiation by tomographic atom probe experiments and microhardness measurements, shows that the kinetics of copper precipitation (in term of dpa calculated using the modified Kinchin-Pease model) is hundred times larger with GeV krypton ions than with MeV electrons and is the same under oxygen and electron irradiations. We show that such a behaviour can be explained only by assuming that the energy deposited in electronic excitations along the path of swift ions is actually able to induce precipitation in metallic supersaturated solid solutions.

  3. Copper, nickel, and iron in plumage of three upland gamebird species from non-contaminated environments

    SciTech Connect

    Parker, G.H.

    1985-12-01

    High levels of atmospheric contamination and particulate fallout characterizing the Industrial Basin of the copper-nickel smelting operations at Sudbury, Ontario, were shown to be reflected in the feather chemistry of resident ruffed grouse populations. Of considerable concern, however, is the paucity of information on background concentrations of elemental metals that could be considered normal for non-contaminated environments. The present report examines concentrations of copper, nickel and iron in the plumage of three tetraonid species collected from remote and undisturbed areas in Northern Ontario and Quebec.

  4. Fabrication of a nanocomposite from in situ iron nanoparticle reinforced copper alloy

    NASA Astrophysics Data System (ADS)

    Wang, Zidong; Wang, Xuewen; Wang, Qiangsong; Shih, I.; Xu, J. J.

    2009-02-01

    In situ iron nanoparticle reinforced Cu-3Sn-8Zn-6Pb alloy has been fabricated by centrifugal casting in a vacuum chamber with a medium frequency electrical furnace. The microstructure of this alloy was analyzed with a scanning electron microscope (SEM) and a high-resolution transmission electron microscope (HRTEM), and the results show that the grains of Cu-3Sn-8Zn-6Pb alloy without iron have a typical dendrite structure with dimensions from 500 to 1500 µm, and the grains of the alloy with the addition of 1% iron are small and equiaxed, with dimensions from 20 to 60 µm. Then, the relatively uniform dispersed particles in the copper matrix were identified with the HRTEM to be pure iron with dimensions in the order of 2-20 nm. The mechanical properties of the alloys were measured and the results show a significant increase in the tensile strength of the alloy with iron nanoparticles and a slight increase of the elongation compared to that without iron. The mechanism of formation of the iron nanoparticles was analyzed by thermodynamic and dynamic theories, and the results indicate that the in situ iron nanoparticles of Cu-3Sn-8Zn-6Pb alloy can reasonably form during solidification in the centrifugal casting technique.

  5. Fabrication of a nanocomposite from in situ iron nanoparticle reinforced copper alloy.

    PubMed

    Wang, Zidong; Wang, Xuewen; Wang, Qiangsong; Shih, I; Xu, J J

    2009-02-18

    In situ iron nanoparticle reinforced Cu-3Sn-8Zn-6Pb alloy has been fabricated by centrifugal casting in a vacuum chamber with a medium frequency electrical furnace. The microstructure of this alloy was analyzed with a scanning electron microscope (SEM) and a high-resolution transmission electron microscope (HRTEM), and the results show that the grains of Cu-3Sn-8Zn-6Pb alloy without iron have a typical dendrite structure with dimensions from 500 to 1500 microm, and the grains of the alloy with the addition of 1% iron are small and equiaxed, with dimensions from 20 to 60 microm. Then, the relatively uniform dispersed particles in the copper matrix were identified with the HRTEM to be pure iron with dimensions in the order of 2-20 nm. The mechanical properties of the alloys were measured and the results show a significant increase in the tensile strength of the alloy with iron nanoparticles and a slight increase of the elongation compared to that without iron. The mechanism of formation of the iron nanoparticles was analyzed by thermodynamic and dynamic theories, and the results indicate that the in situ iron nanoparticles of Cu-3Sn-8Zn-6Pb alloy can reasonably form during solidification in the centrifugal casting technique. PMID:19417426

  6. Copper Cofire X7R Dielectrics and Multilayer Capacitors Based on Zinc Borate Fluxed Barium Titanate Ceramic

    Microsoft Academic Search

    Tae-Ho Song; Clive A. Randall

    2003-01-01

    Copper cofired dielectrics may give new opportunities for high temperature capacitors. To demonstrate feasibility, BaTiO3 has been formulated into X7R dielectrics with copper inner electrodes. This requires the development of a formulation that permits sintering at temperatures below 1000°C, and then firing in a reducing environment in atmospheres pO2 ~ 10-8 atms. ZnO—B2O3 chemistries were explored with additional dopants to

  7. Electronic structure of face-centered-tetragonal iron in ferromagnetic iron-copper multilayers S. J. Lloyd and R. E. Dunin-Borkowski*

    E-print Network

    Dunin-Borkowski, Rafal E.

    Electronic structure of face-centered-tetragonal iron in ferromagnetic iron-copper multilayers S. J are shown to depend on Fe-layer thickness, with the Fe expanded by up to 7% over its cubic lattice parameter. S0163-1829 99 05903-2 I. INTRODUCTION The properties of synthetic multilayers with individual layer

  8. Kinetics and deposit morphology of gold cemented on magnesium, aluminum, zinc, iron and copper from ammonium thiosulfate–ammonia solutions

    Microsoft Academic Search

    M. Karavasteva

    2010-01-01

    The kinetics of gold cementation by magnesium aluminum, zinc, iron and copper at equal conditions as well as the morphology of cementation products and the dissolution of cementing agents were investigated. Both the effect of cementing agents on gold cementation rate and the dissolution of metals decrease in order Cu>Zn>Mg>Fe>Al. High dissolution of magnesium, zinc, iron and copper per mol

  9. Concentration of Copper, Iron, Zinc, Cadmium, Lead, and Nickel in Boar Semen and Relation to the Spermatozoa Quality

    Microsoft Academic Search

    Peter Massányi; Jozef Trandžík; Pavol Nad; Beáta Koréneková; Magdaléna Skalická; Robert Toman; Norbert Luká?; Peter Strapák; Marko Halo; Ján Tur?an

    2003-01-01

    The concentration of copper, iron, zinc, cadmium, lead, and nickel as well as its relation to spermatozoa quality was investigated. The semen samples were analyzed by atomic absorption spectrophotometry (AAS). The concentration of copper in boar semen was 1.64 ± 0.28 mg kg and of iron 16.14 ± 10.35 mg kg. The concentration of zinc in boar semen reached an average value of 171.74 ± 64.72 mg kg and the level of

  10. Serum ceruloplasmin protein expression and activity increases in iron-deficient rats and is further enhanced by higher dietary copper intake

    PubMed Central

    Ranganathan, Perungavur N.; Lu, Yan; Jiang, Lingli; Kim, Changae

    2011-01-01

    Increases in serum and liver copper content are noted during iron deficiency in mammals, suggesting that copper-dependent processes participate during iron deprivation. One point of intersection between the 2 metals is the liver-derived, multicopper ferroxidase ceruloplasmin (Cp) that is important for iron release from certain tissues. The current study sought to explore Cp expression and activity during physiologic states in which hepatic copper loading occurs (eg, iron deficiency). Weanling rats were fed control or low iron diets containing low, normal, or high copper for ? 5 weeks, and parameters of iron homeostasis were measured. Liver copper increased in control and iron-deficient rats fed extra copper. Hepatic Cp mRNA levels did not change; however, serum Cp protein was higher during iron deprivation and with higher copper consumption. In-gel and spectrophotometric ferroxidase and amine oxidase assays demonstrated that Cp activity was enhanced when hepatic copper loading occurred. Interestingly, liver copper levels strongly correlated with Cp protein expression and activity. These observations support the possibility that liver copper loading increases metallation of the Cp protein, leading to increased production of the holo enzyme. Moreover, this phenomenon may play an important role in the compensatory response to maintain iron homeostasis during iron deficiency. PMID:21768302

  11. In-situ formation of barium ferrite in iron doped "tetragonal tungsten bronze": Elaboration of room temperature multiferroic composites

    E-print Network

    Paris-Sud XI, Université de

    of room temperature multiferroic composites E. Castel, , M. Josse* , F. Roulland, D. Michau, L. Raison their room temperature multiferroics properties to the occurrence of barium ferrite parasitic phases in TTB multiferroic composites and thus modulate their magnetic response. Key words Multiferroics

  12. A STUDY on the OPTIMUM CONDITIONS of the CEMENTATION of COPPER in CHLORINATION SOLUTION of CHALCOPYRITE CONCENTRATE by IRON SCRAPS

    Microsoft Academic Search

    Hakan TEMUR; M. Muhtar KOCAKERIM

    Present study aims an experimental design based on the approach of Taguchi method to optimize of cementation of copper in chlorination solutions of chalcopyrite concentrate neutralized with oxidized copper ore by iron scraps. The concentrations of Fe3+, Cu2+, H+, SO4 2- and Cl- ions in the chlorination solution obtained

  13. 78 FR 65573 - Migratory Bird Hunting; Application for Approval of Copper-Clad Iron Shot and Fluoropolymer Shot...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-01

    ...51.1 tungsten, 44.4 Rare Earth copper, 3.9 tin, and Magnet...supreg] iron, 9-16 copper, or Rare Earth and 5-7 nickel. Magnet. Tungsten-matrix...any proportions of Rare Earth tungsten, tin, and Magnet....

  14. Response of a copper(II) and iron(III) ion-selective electrode bielectrode array in saline media.

    PubMed

    De Marco, Roland; Martizano, Jay

    2008-06-15

    A bielectrode array comprising a jalpaite membrane (i.e., Ag(1.5)Cu(0.5)S) copper(II) ion-selective electrode (ISE) and chalcogenide glass membrane (i.e., Fe(2.5)(Se(60)Ge(28)Sb(12))(97.5)) iron(III) ISE has been assembled by individually wiring each solid-state sensor into a single electrode body. Furthermore, a dual metal ion buffer calibration standard incorporating copper(II) and iron(III) coordinating ligands to regulate the levels of free copper(II) and iron(III) in the buffer has been developed to enable simultaneous calibration of the bielectrode ISE array. In this work, the bielectrode ISE array has been employed in the continuous flow analysis (CFA) of free copper(II) and iron(III) in seawater media. It is shown that the individual electrodes displayed Nernstian response in the metal ion buffer calibration standard over a wide dynamic range (viz., 10(-15) to 10(-5) M aCu(2+) and 10(-21) to 10(-11) M aFe(3+)), and the results of repetitive CFA analyses of free copper(II) and iron(III) in seawater are commensurate with the typical values found in coastal seawater samples. Clearly, the bielectrode ISE array may be used in the simultaneous analysis of free copper(II) and iron(III) in seawater without fear of cross-interference between the solid-state sensors. PMID:18585207

  15. Generation of oxidant response to copper and iron nanoparticles and salts: Stimulation by ascorbate

    PubMed Central

    Rice, Robert H.; Vidrio, Edgar A.; Kumfer, Benjamin M.; Qin, Qin; Willits, Neil H.; Kennedy, Ian M.; Anastasio, Cort

    2009-01-01

    The present work describes a two-stage approach to analyzing combustion-generated samples for their potential to produce oxidant stress. This approach is illustrated with the two commonly encountered transition metals, copper and iron. First, their abilities to generate hydroxyl radical were measured in a cell-free, phosphate-buffered saline solution containing ascorbate and/or citrate. Second, their abilities to induce heme oxygenase-1 in cultured human epidermal keratinocytes were assessed in cell culture. Combustion-generated copper oxide nanoparticles were active in both assays and were found to be soluble in culture medium. Depletion of glutathione in the cells or loading the cells with ascorbate greatly increased heme oxygenase-1 induction in the presence of copper. By contrast, iron oxide nanoparticles were active in the phosphate buffered saline but not in cell culture, and they aggregated in culture medium. Soluble salts of copper and iron exhibited the same contrast in activities as the respective combustion-generated particles. The results suggest that the capability of combustion-generated environmental samples to produce oxidant stress can be screened effectively in a two step process, first in phosphate buffered saline with ascorbate and subsequently in epithelial cell culture for those exhibiting activity initially. The results also point to an unanticipated interaction in cells of oxidant stress-generating metals with an anti-oxidant (ascorbate) that is usually missing in culture medium formulations. Thus, ascorbate supplementation of cultured human cells is likely to improve their ability to model the in vivo effects of particulate matter containing copper and other redox-active metals. PMID:19683516

  16. Zinc, copper, iron, and selenium levels in brain and liver of mice exposed to acrylonitrile.

    PubMed

    Rongzhu, Lu; Suhua, Wang; Guangwei, Xing; Chunlan, Ren; Fangan, Han; Junjie, Jing; Aschner, Michael

    2009-07-01

    The mechanism of toxicity of acrylonitrile (AN) has not been fully defined. The research described herein was undertaken to investigate the possible effects of AN on the levels of metallic elements in liver and brain of mice. Thirty-two mice were randomly assigned to four separate groups and treated intraperitoneal (i.p.) once daily for 1 week. Mice in the control group received normal saline, and mice in the three exposure groups received 5, 10, or 20 mg AN/kg b.w. Samples of brain and liver were collected immediately after decapitation. Tissue levels of trace elements (zinc, copper, iron) were determined with flame atomic absorption spectrophotometer or double channel atomic fluorescence absorption spectrophotometer (selenium). Mean brain weights of AN-treated mice were increased as a function of dose compared to controls, but there was no significant change in the ratio of liver/body weight in the four groups. While mean brain zinc decreased as a function of AN dosage, mean liver zinc of the low-dose group significantly increased (p < 0.05); mean liver copper in the medium-dose AN group was significantly higher compared to controls (p < 0.05); however, mean brain copper was increased, but the difference did not attain statistical significance in the three AN groups when compared with the controls (p > 0.05). Mean brain iron levels were significantly decreased in the middle-dose AN group (p < 0.05), but there were no consistent changes in liver iron. Tissue levels of selenium in brain and liver were similar for the control and AN treatment groups. AN induces significant and differential changes in the levels of zinc, copper, and iron in brain and liver. These changes likely play a pivotal role in mediating AN toxicity, most likely via changes in cellular redox status. PMID:19165426

  17. Spectrophotometric determination of iron with 1,10-phenanthroline in the presence of copper

    Microsoft Academic Search

    Zhenpu Wang; K. L. Cheng

    1982-01-01

    Summary Cupric ion forms a very stable complex with triethylenetetramine (trien). It has a very weak absorption at 400–460 nm, however, the ferroin shows a very strong absorption at 480–520 nm. The use of trien-tartrate as duel masking agents for copper has been proved to be successful, and is superior to EDTA or citrate-EDTA in the determination of iron with

  18. Intracellular iron, but not copper, plays a critical role in hydrogen peroxide-induced DNA Damage

    Microsoft Academic Search

    Alexandra Barbouti; Paschalis-Thomas Doulias; Ben-Zhan Zhu; Balz Frei; Dimitrios Galaris

    2001-01-01

    The role of intracellular iron, copper, and calcium in hydrogen peroxide-induced DNA damage was investigated using cultured Jurkat cells. The cells were exposed to low rates of continuously generated hydrogen peroxide by the glucose\\/glucose oxidase system, and the formation of single strand breaks in cellular DNA was evaluated by the sensitive method, single cell gel electrophoresis or “comet” assay. Pre-incubation

  19. Semimicro determination of solubility constants: Copper(II) carbonate and iron(II) carbonate

    Microsoft Academic Search

    F. Reiterer; W. Johannes; H. Gamsjiiger

    1981-01-01

    Summary A semimicro technique for the determination of solubility constants of metal oxides, hydroxides, carbonates and sulphides has been developed and successfully applied to copper(II) and iron(II) carbonate. All experimental data can be interpreted according to the heterogeneous equilibria\\u000a$$\\\\begin{gathered} CuCO_{3(s)} + 2H_{(l)}^ + \\\\rightleftharpoons Cu_{(l)}^{2 + } + CO_{2(g)} + H_2 O_{(l)} ; \\\\hfill \\\\\\\\ ^* K_{ps0} (CuCO_3 )

  20. Influence of orange juice in the levels and in the genotoxicity of iron and copper.

    PubMed

    Franke, Silvia Isabel Rech; Prá, Daniel; Giulian, Raquel; Dias, Johnny Ferraz; Yoneama, Maria Lúcia; da Silva, Juliana; Erdtmann, Bernardo; Henriques, João Antonio Pêgas

    2006-03-01

    World consumption of natural juices is increasing as a consequence of the human search for a healthier life. The juice production industry, especially for orange juice, is expanding in several countries and particularly in Brazil. Despite scientific data reporting beneficial properties derived from juice consumption, some components of juices have been identified as mutagenic or carcinogenic. Carcinogenic or genotoxic effects may be mediated by the interaction of juice components with transition metals or by sub-products of juice auto-oxidation. In this study, the mutagenic potential of orange juice and two metallic agents used in dietary supplementation, FeSO(4) and CuSO(4), were investigated using the comet assay in mouse blood cells (in vivo). Both metal compounds were genotoxic for eukaryotic cells after 24h treatment at the doses used. Significant damage repair was observed after 48h of treatment with the same compounds. Orange juice had a modulating effect on the action of metallic sulfates. In the case of iron treatment, the presence of the orange juice had a preventive, but not restorative, effect. On the other hand, in the case of copper treatment, the effects were both preventive and restorative. PIXE (particle induced X-ray emission) analysis indicated a positive correlation between DNA damage and the hepatic levels of iron and a negative correlation between whole blood copper and DNA damage. A negative correlation between hepatic iron and whole blood copper content was also seen in the treatment with both ferrous and cupric sulfates. PMID:16263202

  1. A chemical potentiator of copper-accumulation used to investigate the iron-regulons of Saccharomyces cerevisiae

    PubMed Central

    Foster, Andrew W; Dainty, Samantha J; Patterson, Carl J; Pohl, Ehmke; Blackburn, Hannah; Wilson, Clare; Hess, Corinna R; Rutherford, Julian C; Quaranta, Laura; Corran, Andy; Robinson, Nigel J

    2014-01-01

    The extreme resistance of Saccharomyces cerevisiae to copper is overcome by 2-(6-benzyl-2-pyridyl)quinazoline (BPQ), providing a chemical-biology tool which has been exploited in two lines of discovery. First, BPQ is shown to form a red (BPQ)2Cu(I) complex and promote Ctr1-independent copper-accumulation in whole cells and in mitochondria isolated from treated cells. Multiple phenotypes, including loss of aconitase activity, are consistent with copper-BPQ mediated damage to mitochondrial iron–sulphur clusters. Thus, a biochemical basis of copper-toxicity in S. cerevisiae is analogous to other organisms. Second, iron regulons controlled by Aft1/2, Cth2 and Yap5 that respond to mitochondrial iron–sulphur cluster status are modulated by copper-BPQ causing iron hyper-accumulation via upregulated iron-import. Comparison of copper-BPQ treated, untreated and copper-only treated wild-type and fra2? by RNA-seq has uncovered a new candidate Aft1 target-gene (LSO1) and paralogous non-target (LSO2), plus nine putative Cth2 target-transcripts. Two lines of evidence confirm that Fra2 dominates basal repression of the Aft1/2 regulons in iron-replete cultures. Fra2-independent control of these regulons is also observed but CTH2 itself appears to be atypically Fra2-dependent. However, control of Cth2-target transcripts which is independent of CTH2 transcript abundance or of Fra2, is also quantified. Use of copper-BPQ supports a substantial contribution of metabolite repression to iron-regulation. PMID:24895027

  2. [Spectroscopic analysis of substituted tetraphenylporphyrin iron, manganese, cobalt, copper and zinc complexes].

    PubMed

    Wang, Lan-zhi; She, Yuan-bin

    2008-10-01

    A full IR, UV-Vis, FIR, spectroscopic analysis on substituted porphyrin iron, manganese, cobalt, copper and Zinc complexes was performed, and the spectroscopic patterns were found for the metalloporphyrin compounds with various structures. Base on molecular structures theory, the reasons for the spectroscopic patterns were discussed deeply. Considering the inconsistency of the far-infrared spectra of the Fe-Cl axial bonds in chloro-iron tetraphenylporphyrins reported in the literature. Their far-infrared absorptions were investigated by using both theoretical analysis and experimental determination, and the results showing that their vibrational frequencies of the Fe--Cl bonds in different substitution chloro-iron tetraphenylporphyrins were associated with their structures, and were linearly related to the length of Fe--Cl bonds. PMID:19123396

  3. Responses of seedling growth and antioxidant activity to excess iron and copper in Triticum aestivum L.

    PubMed

    Li, Xiaoning; Ma, Haizhen; Jia, Pengxiang; Wang, Juan; Jia, Lingyun; Zhang, Tengguo; Yang, Yingli; Chen, Haijian; Wei, Xia

    2012-12-01

    The purpose of this study was to analyze phytotoxicity mechanism involved in root growth and to compare physiological changes in the leaves of wheat seedlings exposed to short term iron (Fe) and copper (Cu) stresses (0, 100, 300 and 500?M). All applied Fe or Cu concentrations reduced root and shoot lengths, but seed germination was inhibited by Cu only at 500?M. Analyses using fluorescent dye 2',7'-dichlorodihydrofluorescein diacetate indicated enhanced H(2)O(2) levels in seedling roots under Fe and Cu treatments. Cu stress at the same concentration induced a great reduction in cell viability and a strong damage on membrane lipid in the roots with respect to Fe treatment. Significant increases in the total chlorophyll (chl) content including chl a and chl b were observed in response to higher Fe concentrations, whereas the highest Cu concentration (500?M) led to significant decreases in the total chl content including chl a. Additionally, leaf peroxidase (POD) and ascorbate peroxidase (APX) were stimulated by Fe stress, but the highest Fe concentration exhibited inhibitory effect on leaf APX activity. In contrast, copper treatment resulted in an elevation in leaf catalase and POD activities. Therefore, H(2)O(2) content in the leaves associated with copper was significantly lower than that with iron at the same concentration. PMID:23025893

  4. Interactions of hydroxycarbamide (hydroxyurea) with iron and copper: implications on toxicity and therapeutic strategies.

    PubMed

    Konstantinou, Eleni; Pashalidis, Ioannis; Kolnagou, Annita; Kontoghiorghes, George J

    2011-01-01

    Presented at the 19th International Conference on Chelation, London, UK, 13-16 November 2009 Preliminary spectrophotometric and potentiometric studies have shown that hydroxycarbamide or hydroxyurea (HU) can interact with copper(II) [Cu(II)], iron(II) [Fe(II)] and Fe(III) ions and form complexes, for example, a ratio of 1 HU:1 metal at pH 5. The affinity for Cu (log ?1 = 3.1) and Fe (log ?1 = 5) by HU is much lower than that of the Fe and Cu chelating drug deferiprone (L1), which is used for the treatment of iron overload. It is anticipated that under certain conditions of high concentrations of these metal ions such as in transfusional iron overload, the therapeutic, pharmacological and toxicological properties of HU could be affected. It is also suggested that excess chelatable and labile forms of Fe or Cu ions, such as non transferrin-bound iron (NTBI) or intracellular low molecular weight labile iron, are among the main factors that may cause variations in the therapeutic response to HU in cancer, sickle cell anemia, thalassemia intermedia and other groups of patients. Further studies are needed to clarify the interaction mechanisms of HU with metal ions in vitro, in vivo and in clinical conditions. PMID:21599436

  5. Zebrafish in the sea of mineral (iron, zinc, and copper) metabolism

    PubMed Central

    Zhao, Lu; Xia, Zhidan; Wang, Fudi

    2014-01-01

    Iron, copper, zinc, and eight other minerals are classified as essential trace elements because they present in minute in vivo quantities and are essential for life. Because either excess or insufficient levels of trace elements can be detrimental to life (causing human diseases such as iron-deficiency anemia, hemochromatosis, Menkes syndrome and Wilson's disease), the endogenous levels of trace minerals must be tightly regulated. Many studies have demonstrated the existence of systems that maintain trace element homeostasis, and these systems are highly conserved in multiple species ranging from yeast to mice. As a model for studying trace mineral metabolism, the zebrafish is indispensable to researchers. Several large-scale mutagenesis screens have been performed in zebrafish, and these screens led to the identification of a series of metal transporters and the generation of several mutagenesis lines, providing an in-depth functional analysis at the system level. Moreover, because of their developmental advantages, zebrafish have also been used in mineral metabolism-related chemical screens and toxicology studies. Here, we systematically review the major findings of trace element homeostasis studies using the zebrafish model, with a focus on iron, zinc, copper, selenium, manganese, and iodine. We also provide a homology analysis of trace mineral transporters in fish, mice and humans. Finally, we discuss the evidence that zebrafish is an ideal experimental tool for uncovering novel mechanisms of trace mineral metabolism and for improving approaches to treat mineral imbalance-related diseases. PMID:24639652

  6. Electrodeposition of iron-cobalt-nickel-copper quaternary system

    NASA Astrophysics Data System (ADS)

    Huang, Qiang

    Electrodeposition is a cost-effective method to produce thin film materials, which have been used widely in the microelectronic industry, and is advantageous to fabricate metal deposits into recessed and curved areas. In this dissertation, a FeCoNiCu quaternary alloy system was investigated, both experimentally and theoretically, for fabrication of multilayers, grating structures, and nanowires. Multilayer structures are composed of alternating ferromagnetic and nonmagnetic nanometric layers, and are of interest due to the giant magnetoresistance (GMR) property it possesses, a change in electric resistance in the presence of an external magnetic field. In addition, the compositional modulation, or the composition contrast, in multilayer structures can be used to develop a grating structured mold for the development of a novel nanoimprinting process. FeCoNiCu was investigated as a more general alloy system containing iron-group metals and a nonmagnetic element, Cu, which can be simplified and adapted to any binary or ternary systems. With a dilute tartrate sulfate bath nanometric multilayers were successfully fabricated with pulse plating and GMR value was reported for this electrodeposited system for the first time. A value of -6% was achieved on rotating disk electrode (RDE) and this maximum occurred when the structure had no preferred crystal phase. Over 40% GMR has been achieved when the multilayer was plated onto a polycrystalline Cu foil. A mathematical model was developed to tailor the deposition process on RDE, and both steady state and nonsteady state cases were simulated. A compositional gradient, which is inherent to a nonsteady state deposition process when the layer size is of nanometer scale was predicted. The quaternary system was explored for other applications. Selective etching of electrodeposited multilayer structures was investigated for different etching solutions. A diluted K2Cr2O 7/H2SO4 solution was successfully developed to produce grating structures for a nanoimprinting mold, which was demonstrated with a simple cast molding process. In addition, nanowire plating was explored with different plating schemes. Nanowires of multilayers were successfully fabricated, and the nanometric layer structure was verified. A deviation was observed in the layer thickness from DC plating, as a result of the nonsteady state plating process, consistent with the model developed.

  7. Effect of dietary calcium and phosphorus levels on the utilization of iron, copper, and zinc by adult males.

    PubMed

    Snedeker, S M; Smith, S A; Greger, J L

    1982-01-01

    Iron, copper, and zinc utilization were examined in nine adult males fed a moderate calcium-moderate phosphorus diet (MCaMP), a moderate calcium-high phosphorus diet (MCaHP), and a high calcium-high phosphorus diet (HCaHP) during a 39-day balance study. The moderate and high calcium diets contained 780 mg and 2382 mg calcium daily, respectively. The moderate and high phosphorus diets contained 843 and 2442 mg phosphorus daily, respectively. The calcium supplements were fed as calcium gluconate, while the phosphorus supplements were fed as glycerol phosphate. Subjects lost more iron and copper in their feces and apparently retained less iron and copper when fed the HCaHP diet than when fed the other two diets, but these effects were not statistically significant. Urinary iron and copper excretion were significantly affected by the dietary treatments. Dietary treatments had no effect on subjects' fecal and urinary losses of zinc nor on their apparent retention of zinc. Plasma iron, zinc, copper, and transferrin levels and serum ferritin levels were not affected by the dietary treatments. PMID:7054462

  8. Arabidopsis Copper Transport Protein COPT2 Participates in the Cross Talk between Iron Deficiency Responses and Low-Phosphate Signaling1[C][W

    PubMed Central

    Perea-García, Ana; Garcia-Molina, Antoni; Andrés-Colás, Nuria; Vera-Sirera, Francisco; Pérez-Amador, Miguel A.; Puig, Sergi; Peñarrubia, Lola

    2013-01-01

    Copper and iron are essential micronutrients for most living organisms because they participate as cofactors in biological processes, including respiration, photosynthesis, and oxidative stress protection. In many eukaryotic organisms, including yeast (Saccharomyces cerevisiae) and mammals, copper and iron homeostases are highly interconnected; yet, such interdependence is not well established in higher plants. Here, we propose that COPT2, a high-affinity copper transport protein, functions under copper and iron deficiencies in Arabidopsis (Arabidopsis thaliana). COPT2 is a plasma membrane protein that functions in copper acquisition and distribution. Characterization of the COPT2 expression pattern indicates a synergic response to copper and iron limitation in roots. We characterized a knockout of COPT2, copt2-1, that leads to increased resistance to simultaneous copper and iron deficiencies, measured as reduced leaf chlorosis and improved maintenance of the photosynthetic apparatus. We propose that COPT2 could play a dual role under iron deficiency. First, COPT2 participates in the attenuation of copper deficiency responses driven by iron limitation, possibly to minimize further iron consumption. Second, global expression analyses of copt2-1 versus wild-type Arabidopsis plants indicate that low-phosphate responses increase in the mutant. These results open up new biotechnological approaches to fight iron deficiency in crops. PMID:23487432

  9. Iron and Copper Act Synergistically To Delay Anaerobic Growth of Bacteria

    PubMed Central

    Bird, Lina J.; Coleman, Maureen L.

    2013-01-01

    Transition metals are known to cause toxic effects through their interaction with oxygen, but toxicity under anoxic conditions is poorly understood. Here we investigated the effects of iron (Fe) and copper (Cu) on the anaerobic growth and gene expression of the purple phototrophic bacterium Rhodopseudomonas palustris TIE-1. We found that Fe(II) and Cu(II) act synergistically to delay anaerobic growth at environmentally relevant metal concentrations. Cu(I) and Cu(II) had similar effects both alone and in the presence of ascorbate, a Cu(II) reductant, indicating that reduction of Cu(II) to Cu(I) by Fe(II) is not sufficient to explain the growth inhibition. Addition of Cu(II) increased the toxicity of Co(II) and Ni(II); in contrast, Ni(II) toxicity was diminished in the presence of Fe(II). The synergistic anaerobic toxicity of Fe(II) and Cu(II) was also observed for Escherichia coli MG1655, Shewanella oneidensis MR-1, and Rhodobacter capsulatus SB1003. Gene expression analyses for R. palustris identified three regulatory genes that respond to Cu(II) and not to Fe(II): homologs of cueR and cusR, two known proteobacterial copper homeostasis regulators, and csoR, a copper regulator recently identified in Mycobacterium tuberculosis. Two P-type ATPase efflux pumps, along with an FoF1 ATP synthase, were also upregulated by Cu(II) but not by Fe(II). An Escherichia coli mutant deficient in copA, cus, and cueO showed a smaller synergistic effect, indicating that iron might interfere with one or more of the copper homeostasis systems. Our results suggest that interactive effects of transition metals on microbial physiology may be widespread under anoxic conditions, although the molecular mechanisms remain to be more fully elucidated. PMID:23563938

  10. Contact Killing of Bacteria on Copper Is Suppressed if Bacterial-Metal Contact Is Prevented and Is Induced on Iron by Copper Ions

    PubMed Central

    Mathews, Salima; Hans, Michael

    2013-01-01

    Bacteria are rapidly killed on copper surfaces, and copper ions released from the surface have been proposed to play a major role in the killing process. However, it has remained unclear whether contact of the bacteria with the copper surface is also an important factor. Using laser interference lithography, we engineered copper surfaces which were covered with a grid of an inert polymer which prevented contact of the bacteria with the surface. Using Enterococcus hirae as a model organism, we showed that the release of ionic copper from these modified surfaces was not significantly reduced. In contrast, killing of bacteria was strongly attenuated. When E. hirae cells were exposed to a solid iron surface, the loss of cell viability was the same as on glass. However, exposing cells to iron in the presence of 4 mM CuSO4 led to complete killing in 100 min. These experiments suggest that contact killing proceeds by a mechanism whereby the metal-bacterial contact damages the cell envelope, which, in turn, makes the cells susceptible to further damage by copper ions. PMID:23396344

  11. Thermodynamic and Structural Aspects of Equilibrium and Mechanically Milled Yttrium BARIUM(2) COPPER(3) OXYGEN(6+DELTA) Powder

    NASA Astrophysics Data System (ADS)

    Lee, David Soong-Hua

    The equilibrium relationships between partial pressure of oxygen, temperature, lattice parameters and oxygen content in the YBa_2Cu_3O _{6+delta} superconductor were examined by differential scanning calorimetry, high -temperature x-ray diffraction, thermogravimetric analysis and measurement of pressure versus concentration isotherms. Oxygen pressures ranged from 1 mbar to 1013 mbar and temperatures ranged from 400^circC to 750 ^circC. Lattice parameters as a function of temperature and partial pressure of oxygen were measured. P(c) isotherms and TGA were used to measure oxygen content as a function of temperature. A phase line separating the low temperature orthorhombic phase and the high temperature tetragonal phase was determined. No evidence of a miscibility gap between the two phases was found in the range of temperatures and oxygen pressures explored. From the data, the excess enthalpy and entropy through the orthorhombic to tetragonal phase transition was calculated. It was found that the excess entropy is less than the entropy of mixing for an ideal solution. DSC was used to measure enthalpies for the transition and to calculate activation energies for the process. High temperature x-ray diffraction and differential scanning calorimetry were used to study the effect of high energy mechanical deformation on the structural and thermal characteristics of YBa_2Cu_3O _{6+delta} powder. Broadening of Bragg peaks due to the reduction of grain size makes the distinction between orthorhombic and tetragonal phases of YBa_2Cu _3O_{6+delta} difficult after only one hour of ball milling. The equilibrium orthorhombic to tetragonal phase transition may occur within the first hour of ball-milling. Longer milling times (> 5hrs) produce a cationic disorder on the yttrium and barium sites. A metastable cubic (Y_ {1/3}Ba_{2/3} )CuO_{2+delta} structure with a = 3.86A is formed. Further mechanical deformation does not induce the formation of an amorphous phase; rather, an eventual decomposition into the constituent oxides Y_2O_3 and BaCuO_2 is observed. Annealing of the metastable cubic (Y_{1/3} Ba_{2/3})CuO _{2+delta} phase in relatively low pressures of oxygen (>=100mbar) and at moderate temperatures (~400 -600^circC) produces an as yet unidentified cubic phase which is unstable in air and has a lattice constant of a = 5.47A.

  12. Effect of adsorbed chlorine and oxygen on shear strength of iron and copper junctions

    NASA Technical Reports Server (NTRS)

    Wheeler, D. R.

    1975-01-01

    Static friction experiments were performed in ultrahigh vacuum at room temperature on copper, iron, and steel contacts selectively contaminated with oxygen and chlorine in submonolayer amounts. The concentration of the adsorbates was determined with Auger electron spectroscopy and was measured relative to the saturation concentration of oxygen on iron (concentration 1.0). The coefficient of static friction decreased with increasing adsorbate concentration. It was independent of the metal and the adsorbate. The results compared satisfactorily with an extension of the junction growth theory to heterogeneous interfaces. The reduction in interfacial shear strength was measured by the ratio sub a/sub m where sub a is the shear strength of the interface with an adsorbate concentration of 1.0, and sub m is the strength of the clean metal interface. This ratio was 0.835 + or - 0.012 for all the systems tested.

  13. Different Mechanisms Between Copper and Iron in Catecholamines-Mediated Oxidative DNA Damage and Disruption of Gene Expression In Vitro

    Microsoft Academic Search

    Yoshihiko Nishino; Motozumi Ando; Rena Makino; Koji Ueda; Yoshinori Okamoto; Nakao Kojima

    2011-01-01

    Catechols produce reactive oxygen species (ROS) and induce oxidative DNA damage through reduction–oxidation reactions with\\u000a metals such as copper. Here, we examined oxidative DNA damage by neurotransmitter catecholamines in the presence of copper\\u000a or iron and evaluated the effects of this damage on gene expression in vitro. Dopamine induced strand breaks and base oxidation\\u000a in calf thymus DNA in the

  14. Copper and iron concentrations in Ascophyllum nodosum (Fucales, Phaeophyta) from different sites in Ireland and after culture experiments in relation to thallus age and epiphytism

    Microsoft Academic Search

    Dagmar B. Stengel; Matthew J. Dring

    2000-01-01

    In laboratory experiments, copper concentrations in plants of Ascophyllum nodosum (L.) Le Jolis (Fucales, Phaeophyta) increased with the concentrations in the culture media and were highest in younger, meristematic thallus parts. After initial accumulation in high-copper medium and subsequent transfer to clean seawater for 5 days, no release of copper could be detected. Iron concentrations in A. nodosum tissue were

  15. SOURCE ASSESSMENT: MAJOR BARIUM CHEMICALS

    EPA Science Inventory

    This report summarizes data on air emissions from the production of major barium chemicals. Compounds studied include barium sulfide, barium carbonate, barium chloride, barium hydroxide, and barium sulfate. In order to evaluate potential environmental effects the source severity,...

  16. Phase relations of bismuth-barium-strontium oxides and copper L x-ray spectroscopy of cuprates including YBCO

    NASA Astrophysics Data System (ADS)

    Muller, Karoline

    Three studies are presented. In the first, phase relations are determined for the Bi-Ba oxide pseudobinary (<50% BaO) in oxygen at 640-1000 °C. Essentially no BaO dissolves in alpha-Bi2O3. The other phases are solid solutions. The delta-Bi2O3 polymorph, stable at 730-825 °C, belongs to a face-centered cubic phase (FCC SS). BaO-saturated FCCSS and BiO1.5-saturated rhombohedral phase (beta) melt eutectically at 753 °C. BaO-saturated beta coexists with Bi3BaO5.5. The eutectic between beta and Bi3BaO5.5, is at 775+/-6 °C. At T<815 °C, Bi3BaO5.5 coexists with BiBaO3. A tetragonal phase (T4) forms by reaction of Bi3BaO 5.5 and BiBaO3. Bi3BaO5.5 melts incongruently at 820 °C to liquid and T4. T4 melts incongruently to liquid and BiBaO3. delta-Bi2O3 and beta, both anion conductors, have structures based on that of fluorite. Other oxides have perovskite-like structures. Bi in BiBaO3 is half pentavalent and half trivalent; other oxides have all Bi3+. Phase relations of the Bi-Ba-Sr oxide ternary were investigated at 725 °C (alkaline earth oxide <50%). The oxygen ion conducting beta phase and BaBiO3 do not coexist in a binary system. (Ba,Sr)O-containing beta is in equilibrium with the electronic conductor BaBiO3. Cu L-spectra of superconductors and related materials were determined to investigate the atomic environment of Cu. Spectra may be micron-scale probes of copper valence because Lalpha- and Lbeta x-rays result from 3d valence band?2p transitions. Energies of Cu Lalpha and Lbeta x-rays are ?940 eV and reproducible to 0.15 eV. Pure emission L spectra of Cu phases are similar; measured differences largely result from absorption. Cu self-absorption spectra are ratios of L emission spectra obtained with different accelerating potentials of primary electrons. CuO and Cu2O have identical Lalpha and Lbeta energies but differ in Lbeta-Lalpha intensity ratio. Greater self-absorption of Lbeta x-rays than Lalpha in Cu2O compared with CuO is due to shifts in L absorption edge energies. Different YBCO samples differ slightly in Lbeta-Lalpha ratio according to oxygen content; again a result of changes in self-absorption. Different Cu2+-bearing phases have slight differences in absorption edge positions so Lbeta-Lalpha ratio depends on bulk composition as well as copper valence.

  17. Iron(III) extraction by LIX 860 and its influence on copper(II) extraction from sulphuric solutions

    Microsoft Academic Search

    J. Simpson; P. Navarro; F. J. Alguacil

    1996-01-01

    Solvent extraction of iron(III) by means of the commercial salicylaldoxime LIX 860 and its influence on copper(II) extraction from sulphuric solutions has been studied. Extraction experiments were carried out varying the equilibration time, temperature, extractant concentration, aqueous pH and the ferric and cupric ions concentrations. Iron(III) extraction by LIX 860 can be represented by the reaction: Fe3aq+3HRorg?FeR3org+3H+aq in which HR

  18. Content of iron, copper and zinc in white sugar samples from Polish and other European sugar factories

    Microsoft Academic Search

    M. Wojtczak; B. Król

    2002-01-01

    White sugar is a very pure food product, even though it contains very small, significant amounts of soluble and insoluble impurities. The content of these impurities has nutritional significance and determines the usefulness of sugar for various industrial applications. The aim was to evaluate the content of iron, copper and zinc in samples of white sugar from Polish factories compared

  19. Uptake of iron, zinc, manganese, and copper by seedlings of hybrid and traditional rice cultivars from different soil types

    Microsoft Academic Search

    X. Yang; V. Römheld; H. Marschner

    1994-01-01

    In pot experiments, uptake of zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn) by hybrid rice from different soil types was compared with a traditional rice (Oryza sativa L.) cultivar. The concentration and total uptake of Fe in the shoots of hybrid rice grown in Oxisol and Ultisol were lower than those of the traditional cultivar. The concentration and

  20. Structure of self-interstitial atom clusters in iron and copper

    SciTech Connect

    Takahashi, Akiyuki [Department of Mechanical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510 (Japan); Ghoniem, Nasr M. [Department of Mechanical and Aerospace Engineering, University of California-Los Angeles, Los Angeles, California 90095 (United States)

    2009-11-01

    The dislocation core structure of self-interstitial atom (SIA) clusters in bcc iron and fcc copper is determined using the hybrid ab initio continuum method of Banerjee et al. [Philos. Mag. 87, 4131 (2007)]. To reduce reliance on empirical potentials and to facilitate predictions of the effects of local chemistry and stress on the structure of defects, we present here a hybrid extension of the Peierls-Nabarro continuum model, with lattice resistance to slip determined separately from ab initio calculations. A method is developed to reconstruct atomic arrangements and geometry of SIA clusters from the hybrid model. The results are shown to compare well with molecular-dynamics simulations. In iron, the core structure does not show dependence on the size of the self-interstitial cluster, and is nearly identical to that of a straight edge dislocation. However, the core structure of SIA clusters in Cu is shown to depend strongly on the cluster size. Small SIA clusters are found to have nondissociated compact dislocation cores, with a strong merging of Shockley partial dislocations and a relatively narrow stacking fault (SF) region. The compact nature of the SIA core in copper is attributed to the strong dependence of the self-energy on the cluster size. As the number of atoms in the SIA cluster increases, Shockley partial dislocations separate and the SF region widens, rendering the SIA core structure to that of an edge dislocation. The separation distance between the two partials widens as the cluster size increases, and tends to the value of a straight edge dislocation for cluster sizes above 400 atoms. The local stress is found to have a significant effect on the atomic arrangements within SIA clusters in copper and the width of the stacking faults. An applied external shear can delocalize the core of an SIA cluster in copper, with positive shear defined to be on the (111) plane along the [112] direction. For an SIA cluster containing 1600 atoms, a positive 1 GPa shear stress delocalizes the cluster and expands the SF to 30b, while a negative shear stress of 2 GPa contracts the core to less than 5b, where b is the Burgers vector magnitude.

  1. Structure of self-interstitial atom clusters in iron and copper

    NASA Astrophysics Data System (ADS)

    Takahashi, Akiyuki; Ghoniem, Nasr M.

    2009-11-01

    The dislocation core structure of self-interstitial atom (SIA) clusters in bcc iron and fcc copper is determined using the hybrid ab initio continuum method of Banerjee [Philos. Mag. 87, 4131 (2007)]. To reduce reliance on empirical potentials and to facilitate predictions of the effects of local chemistry and stress on the structure of defects, we present here a hybrid extension of the Peierls-Nabarro continuum model, with lattice resistance to slip determined separately from ab initio calculations. A method is developed to reconstruct atomic arrangements and geometry of SIA clusters from the hybrid model. The results are shown to compare well with molecular-dynamics simulations. In iron, the core structure does not show dependence on the size of the self-interstitial cluster, and is nearly identical to that of a straight edge dislocation. However, the core structure of SIA clusters in Cu is shown to depend strongly on the cluster size. Small SIA clusters are found to have nondissociated compact dislocation cores, with a strong merging of Shockley partial dislocations and a relatively narrow stacking fault (SF) region. The compact nature of the SIA core in copper is attributed to the strong dependence of the self-energy on the cluster size. As the number of atoms in the SIA cluster increases, Shockley partial dislocations separate and the SF region widens, rendering the SIA core structure to that of an edge dislocation. The separation distance between the two partials widens as the cluster size increases, and tends to the value of a straight edge dislocation for cluster sizes above 400 atoms. The local stress is found to have a significant effect on the atomic arrangements within SIA clusters in copper and the width of the stacking faults. An applied external shear can delocalize the core of an SIA cluster in copper, with positive shear defined to be on the (111) plane along the [1¯1¯2] direction. For an SIA cluster containing 1600 atoms, a positive 1 GPa shear stress delocalizes the cluster and expands the SF to 30b , while a negative shear stress of 2 GPa contracts the core to less than 5b , where b is the Burgers vector magnitude.

  2. COPPER

    EPA Science Inventory

    The report is a review of current knowledge of the distribution of copper in the environment and living things. Metabolism and the effects of copper in the biosphere are also considered. Copper compounds are common and widely distributed in nature. They are also extensively mined...

  3. Selective nucleation of iron phthalocyanine crystals on micro-structured copper iodide.

    PubMed

    Rochford, Luke A; Ramadan, Alexandra J; Heutz, Sandrine; Jones, Tim S

    2014-12-14

    Morphological and structural control of organic semiconductors through structural templating is an efficient route by which to tune their physical properties. The preparation and characterisation of iron phthalocyanine (FePc)-copper iodide (CuI) bilayers at elevated substrate temperatures is presented. Thin CuI(111) layers are prepared which are composed of isolated islands rather than continuous films previously employed in device structures. Nucleation in the early stages of FePc growth is observed at the edges of islands rather than on the top (111) faces with the use of field emission scanning electron microscopy (FE-SEM). Structural measurements show two distinct polymorphs of FePc, with CuI islands edges nucleating high aspect ratio FePc crystallites with modified intermolecular spacing. By combining high substrate temperature growth and micro-structuring of the templating CuI(111) layer structural and morphological control of the organic film is demonstrated. PMID:25340949

  4. Predicting copper-, iron-, and zinc-binding proteins in pathogenic species of the Paracoccidioides genus

    PubMed Central

    Tristão, Gabriel B.; Assunção, Leandro do Prado; dos Santos, Luiz Paulo A.; Borges, Clayton L.; Silva-Bailão, Mirelle Garcia; Soares, Célia M. de Almeida; Cavallaro, Gabriele; Bailão, Alexandre M.

    2015-01-01

    Approximately one-third of all proteins have been estimated to contain at least one metal cofactor, and these proteins are referred to as metalloproteins. These represent one of the most diverse classes of proteins, containing metal ions that bind to specific sites to perform catalytic, regulatory and structural functions. Bioinformatic tools have been developed to predict metalloproteins encoded by an organism based only on its genome sequence. Its function and the type of metal binder can also be predicted via a bioinformatics approach. Paracoccidioides complex includes termodimorphic pathogenic fungi that are found as saprobic mycelia in the environment and as yeast, the parasitic form, in host tissues. They are the etiologic agents of Paracoccidioidomycosis, a prevalent systemic mycosis in Latin America. Many metalloproteins are important for the virulence of several pathogenic microorganisms. Accordingly, the present work aimed to predict the copper, iron and zinc proteins encoded by the genomes of three phylogenetic species of Paracoccidioides (Pb01, Pb03, and Pb18). The metalloproteins were identified using bioinformatics approaches based on structure, annotation and domains. Cu-, Fe-, and Zn-binding proteins represent 7% of the total proteins encoded by Paracoccidioides spp. genomes. Zinc proteins were the most abundant metalloproteins, representing 5.7% of the fungus proteome, whereas copper and iron proteins represent 0.3 and 1.2%, respectively. Functional classification revealed that metalloproteins are related to many cellular processes. Furthermore, it was observed that many of these metalloproteins serve as virulence factors in the biology of the fungus. Thus, it is concluded that the Cu, Fe, and Zn metalloproteomes of the Paracoccidioides spp. are of the utmost importance for the biology and virulence of these particular human pathogens. PMID:25620964

  5. Regulation of Brain Iron and Copper Homeostasis by Brain Barrier Systems: Implication in Neurodegenerative Diseases

    PubMed Central

    Zheng, Wei; Monnot, Andrew D.

    2011-01-01

    Iron (Fe) and copper (Cu) are essential to neuronal function; excess or deficiency of either is known to underlie the pathoetiology of several commonly known neurodegenerative disorders. This delicate balance of Fe and Cu in the central milieu is maintained by the brain barrier systems, i.e., the blood-brain barrier (BBB) between the blood and brain interstitial fluid and the blood- cerebrospinal fluid barrier (BCB) between the blood and cerebrospinal fluid (CSF). This review provides a concise description on the structural and functional characteristics of the brain barrier systems. Current understanding of Fe and Cu transport across the brain barriers is thoroughly examined, with major focuses on whether the BBB and BCB coordinate the direction of Fe and Cu fluxes between the blood and brain/CSF. In particular, the mechanism by which pertinent metal transporters in the barriers, such as the transferrin receptor (TfR), divalent metal transporter (DMT1), copper transporter (CTR1), ATP7A/B, and ferroportin (FPN), regulate metal movement across the barriers is explored. Finally, the detrimental consequences of dysfunctional metal transport by brain barriers, as a result of endogenous disorders or exogenous insults, are discussed. Understanding the regulation of Fe and Cu homeostasis in the central nervous system aids in the design of new drugs targeted on the regulatory proteins at the brain barriers for the treatment of metal’s deficiency or overload-related neurological diseases. PMID:22115751

  6. Separation of iron(III), copper(II) and zinc(II) from a mixed sulphate\\/chloride solution using TBP, LIX 84I and Cyanex 923

    Microsoft Academic Search

    K. Sarangi; P. K. Parhi; E. Padhan; A. K. Palai; K. C. Nathsarma; K. H. Park

    2007-01-01

    Separation of iron(III), copper(II) and zinc(II) from a mixed sulphate\\/chloride leach liquor bearing 11.8kg\\/m3 iron, 24.8kg\\/m3 copper, 0.23kg\\/m3 zinc, 3.8kg\\/m3 cobalt, 35.2kg\\/m3 nickel, 176.3kg\\/m3 chloride and 48.9kg\\/m3 sulphate was carried out using solvent extraction. Iron, copper and zinc extraction studies were carried out using TBP, LIX 84I and Cyanex 923 in kerosene, respectively. The extraction studies were carried out for

  7. Hepatic and hippocampus iron status is not altered in response to increased serum ceruloplasmin and serum "free" copper in Wistar rat model for non-Wilsonian brain copper toxicosis.

    PubMed

    Pal, Amit; Vasishta, Rakesh kumar; Prasad, Rajendra

    2013-09-01

    Copper and iron dyshomeostasis has been implicated directly or indirectly in the pathogenesis of neurodegenerative diseases. Previously, we have shown the first in vivo evidence of significant increase in the hippocampus copper and zinc content with spatial memory impairments, astrocytes swelling (Alzheimer type-II cells) coupled with increase in the number of astrocytes, copper deposition in the choroid plexus, and degenerated neurons in copper-intoxicated Wistar rats. In continuation with our previous study, the aim of this study was to further investigate the effects of intraperitoneally injected copper lactate (0.15 mg Cu/100 g body weight) daily for 90 days on serum "free" copper levels, iron levels in the liver, and hippocampus by atomic absorption spectrophotometry and histopathological study of the liver and brain tissues of Wistar rats using Perls' Prussian blue (PPB) stain. A massive significant increase in serum "free" copper (79.48% increase) along with strong correlation (r = 0.978) was found between serum copper and serum "free" copper in copper-intoxicated rats. No significant difference was detected in hepatic and hippocampus iron levels between control and copper-intoxicated rats. PPB stain demonstrated very few scattered grade 1 haemosiderin deposits within sinusoidal cells predominantly Kupffer cells; however, brain sections were negatively stained with PPB stain. In conclusion, the current study demonstrates that chronic copper toxicity causes increase in serum "free" copper, which may serve as predisposing factor for the development of neurodegeneration and memory deficits, and grade 1 haemosiderin deposition in Kupffer cells without altering hepatic and hippocampus iron levels in male Wistar rats. PMID:23872735

  8. Copper deficient rats and mice both develop anemia but only rats have lower plasma and brain iron levels

    PubMed Central

    Pyatskowit, Joshua W.; Prohaska, Joseph R.

    2008-01-01

    Iron homeostasis depends on adequate dietary copper but the mechanisms are unknown. Mice (Mus musculus) and rat (Rattus norvegicus) offspring were compared to determine the effect of dietary copper deficiency (Cu-) on iron status of plasma, liver, brain and intestine. Holtzman rat and Hsd:ICR (CD-1) outbred albino mouse dams were fed a Cu- diet and drank deionized water or Cu supplemented water. Offspring were sampled at time points between postnatal ages 13 and 32. Cu- rat and mouse pups were both anemic, but only rat pups had lower plasma and brain iron levels. Plasma iron was lower throughout the suckling period in Cu- rats but not Cu-mice. Cu- mice derived from dams restricted of Cu only during lactation were also severely anemic without hypoferremia. Intestinal metal analysis confirmed that Cu- pups had major reductions in intestinal concentration of Cu, increased Fe, and normal Zn. However, whole mouse (less the intestine) analysis demonstrated normal content of Fe indicating that the limitation in iron transport by intestinal hephaestin had no consequence to total iron reserves of the mouse. Further research will be needed to determine the reason Cu- mice were anemic since the “ferroxidase” hypothesis does not explain this phenotype. PMID:18178529

  9. The Work Function of Copper

    Microsoft Academic Search

    Paul A. Anderson

    1949-01-01

    The work functions and aging characteristics of fourteen copper surfaces have been determined by measurement of their contact differences of potential with respect to barium reference surfaces of known work function. Measurement was by the retarding potential method in tubes sealed from the pumps and gettered with vaporized barium. The copper surfaces were prepared by subjecting Hilger's \\

  10. Molecular bases of copper and iron deficiency-associated dyslipidemia: a microarray analysis of the rat intestinal transcriptome.

    PubMed

    Tosco, Alessandra; Fontanella, Bianca; Danise, Rosa; Cicatiello, Luigi; Grober, Olì M V; Ravo, Maria; Weisz, Alessandro; Marzullo, Liberato

    2010-03-01

    As essential cofactor in many proteins and redox enzymes, copper and iron are involved in a wide range of biological processes. Mild dietary deficiency of metals represents an underestimated problem for human health, because it does not cause clear signs and clinical symptoms, but it is associated to long-term deleterious effects in cardiovascular system and alterations in lipid metabolism. The aim of this work was to study the biological processes significantly affected by mild dietary deficiency of both metals in rat intestine, in order to better understand the molecular bases of the systemic metabolic alterations, as hypercholesterolemia and hypertriglyceridemia observed in copper-deficient rats. A gene-microarray differential analysis was carried out on the intestinal transcriptome of copper- and iron-deficient rats, thus highlighting the biological processes significantly modulated by the dietary restrictions. The gene array analysis showed a down-regulation of genes involved in mitochondrial and peroxisomal fatty acids beta-oxidation and an up-regulation of genes involved in plasmatic cholesterol transport (apoprotein E and lecithin:cholesterol acyltransferase) in copper deficiency. Furthermore, a severe down-regulation of ApoH was pointed out in iron-deficient animals. PMID:19821111

  11. Cytotoxic analogs of the iron(III) chelator pyridoxal isonicotinoyl hydrazone: effects of complexation with copper(II), gallium(III), and iron (III) on their antiproliferative activities.

    PubMed Central

    Richardson, D R

    1997-01-01

    This study examined if complexation with metals increased the antiproliferative activities of chelators of the pyridoxal isonicotinoyl hydrazone (PIH) class. Addition of iron(III) to some PIH analogs markedly depressed their activities, whereas it had little effect on others. The gallium(III) complex of PIH, but not its copper(II) complex, was more efficient than the apochelator at inhibiting [3H]thymidine incorporation. PMID:9303419

  12. Doping effect on the Janus-like structure of a copper-iron bimetallic nanocluster and its solid-liquid phase transition

    NASA Astrophysics Data System (ADS)

    Taherkhani, Farid; Seresht, Pegah Freshteh

    2015-04-01

    A molecular dynamics simulation with a new-application potential model has been explored for melting temperature, radial distribution of iron-copper bimetallic nanoclusters, and their bulk for the first time. At low copper weight percentages, the melting temperature changes a little for the bulk structures; however, for nanostructures, the variation of melting temperature is significant. At medium copper-doping values, there is a melting-temperature plateau in bimetallic nanoclusters. For many catalysis applications, Janus-like structures are considered, which occur at around 53% iron weight in copper at room temperature, when copper-iron bimetallic nanoclusters clearly consist of two distinct faces. Our result for the melting temperature of the bulk alloy confirms the experimental result.

  13. Determination of copper, iron, and nickel in oils and fats by direct graphite furnace atomic absorption spectrometry: summary of collaborative study.

    PubMed

    Capar, S G

    1990-01-01

    A collaborative study of a method for the determination of copper, iron, and nickel in edible oils and fats by direct graphite furnace atomic absorption spectrometry was recently conducted by the International Union of Pure and Applied Chemistry. The quantitation limits of the method are 5 micrograms/kg for copper and 10 micrograms/kg for iron and nickel. The method has been adopted official first action as an IUPAC-AOAC method. PMID:2324041

  14. The distribution of copper, manganese, zinc, and iron in antarctic waters and the relation of the concentrations of these metals to biological primary productivity 

    E-print Network

    Arhelger, Martin Edward

    1967-01-01

    THE DISTRIBUTION OF COPPER, MANGANESE, ZINC, AND IRON IN ANTARCTIC WATERS AND THE RELATION OF THE CONCENTRATIONS OF THESE METALS TO BIOLOGICAL PRIMARY PRODUCTIVITY A Thesis By MARTIN EDWARD ARHELGER Submitted to the Graduate College... of the Texas A& 1 University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August I967 Major Subj ect: CHEMICAL OCEANOGRAPHY THE DISTRIBUTION OF COPPER, MANGANESE, ZINC, AND IRON IN ANTARCTIC WATERS AND THE RELATION...

  15. The Menkes\\/Wilson Disease Gene Homologue in Yeast Provides Copper to a Ceruloplasmin-Like Oxidase Required for Iron Uptake

    Microsoft Academic Search

    Daniel S. Yuan; Robert Stearman; Andrew Dancis; Teresa Dunn; Troy Beeler; Richard D. Klausner

    1995-01-01

    The CCC2 gene of the yeast Saccharomyces cerevisiae is homologous to the human genes defective in Wilson disease and Menkes disease. A biochemical hallmark of these diseases is a deficiency of copper in ceruloplasmin and other copper proteins found in extracytosolic compartments. Here we demonstrate that disruption of the yeast CCC2 gene results in defects in respiration and iron uptake.

  16. An intrusion-related origin for Cu–Au mineralization in iron oxide–copper–gold (IOCG) provinces

    Microsoft Academic Search

    Peter J. Pollard

    2006-01-01

    Major Cu–Au deposits of iron oxide–copper–gold (IOCG) style are temporally associated with oxidized, potassic granitoids similar to those linked to major porphyry Cu–Au deposits. Stable and radiogenic isotope evidence indicates fluids and ore components were likely sourced from the intrusions. IOCG deposits form over a range of crustal levels because CO2-rich fluids separate from the magmas at higher pressures than

  17. Molecular bases of copper and iron deficiency-associated dyslipidemia: a microarray analysis of the rat intestinal transcriptome

    Microsoft Academic Search

    Alessandra Tosco; Bianca Fontanella; Rosa Danise; Luigi Cicatiello; Olì M. V. Grober; Maria Ravo; Alessandro Weisz; Liberato Marzullo

    2010-01-01

    As essential cofactor in many proteins and redox enzymes, copper and iron are involved in a wide range of biological processes.\\u000a Mild dietary deficiency of metals represents an underestimated problem for human health, because it does not cause clear signs\\u000a and clinical symptoms, but it is associated to long-term deleterious effects in cardiovascular system and alterations in lipid\\u000a metabolism. The

  18. Iron, zinc and copper levels in brain, serum and liver of neonates exposed to 2,4-dichlorophenoxyacetic acid

    Microsoft Academic Search

    Alejandro Ferri; Ricardo Duffard; Nelson Stürtz; Ana Mar??a Evangelista de Duffard

    2003-01-01

    The effects of 2,4-dichlorophenoxyacetic acid (2,4-D, 70 or 100 mg\\/kg dam's body weight) on iron (Fe), zinc (Zn) and copper (Cu) in brain, liver and serum of well-nourished and undernourished pups exposed through dam's milk were determined. Undernourishment produced a high Fe decrease (serum and brain) and a delay in weight gain similar to that produced by the highest dose

  19. MULTIPLE MENKES COPPER ATPASE (ATP7A) TRANSCRIPT AND PROTEIN VARIANTS ARE INDUCED BY IRON DEFICIENCY IN RAT DOUDENAL ENTEROCYTES

    PubMed Central

    Lu, Yan; Kim, Changae; Collins, James F.

    2013-01-01

    The Menkes copper ATPase (Atp7a) pumps copper into the trans-Golgi for cuproenzyme synthesis, and translocates to the basolateral membrane of enterocytes for copper export. Recent studies demonstrated that three 5’ end splice variants of the Atp7a transcript exist in rat duodenum, all of which are strongly induced during iron deprivation. To explore a possible role for Atp7a (and copper) in intestinal iron absorption, the current studies were undertaken to test the hypothesis that multiple Atp7a transcript and protein variants exist in intestinal epithelial cells. Northern blot analyses using probes generated from the full-length Atp7a cDNA revealed several specific hybridization bands, all of which were more intense in RNA samples extracted from duodenal enterocytes isolated from iron-deficient rats. A PCR-based approach, using forward primers specific for the alternative 5’ end splice variants and a reverse primer in exon 23, demonstrated that 3 full-length transcripts exist in rat IEC-6 cells. To identify possible Atp7a protein variants, three distinct polyclonal antisera were utilized. The specificity of the antisera was first established by western blotting and immunoprecipitation studies using samples derived from isolated rat enterocytes and Atp7a knockdown IEC-6 cells. Several specific immunoreactive bands were documented, and a unique Atp7a protein distribution in cytosolic vesicle-like structures was noted. In conclusion, multiple Atp7a transcript and protein variants exist in rodent intestinal epithelial cells and are induced by dietary iron deprivation. Further studies will be designed to determine the subcellular distribution of Atp7a protein variants and possible unique functions of each. PMID:22579041

  20. The effect of malathion, diazinon, and various concentrations of zinc, copper, nickel, lead, iron, and mercury on fish

    Microsoft Academic Search

    M. K. Alam; O. E. Maughan

    1992-01-01

    Acute and chronic toxicity tests for malathion, diazinon, copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), nickel (Ni), and\\u000a iron (Fe) were conducted. Mortalities ofBarilius vagra andCyprinus carpio (common carp) were variable but LC50-96 hr were similar for pesticides. AdultB. vagra seem to be more sensitive to malathion than juvenile carp. Both juvenile carp and adultB. vagra were extremely sensitive

  1. Impact of selenium, iron, copper and zinc in on\\/off Parkinson’s patients on L-dopa therapy

    Microsoft Academic Search

    G. A. Qureshi; A. A. Qureshi; S. A. Memon; S. H. Parvez

    We have quantitated CSF and serum levels of Selenium, iron, copper and zinc by Atomic absorption spectrophotometer in 36 patients\\u000a with parkinson’s disease all on L-dopa therapy. Out of these 19 showed on or positive response to L-dopa where as 21 patients\\u000a showed on and off response. These data were compared with 21 healthy controls. The results showed that serum

  2. Acyloxylation of 1,4-Dioxanes and 1,4-Dithianes Catalyzed by a Copper-Iron Mixed Oxide.

    PubMed

    García-Cabeza, Ana Leticia; Marín-Barrios, Rubén; Moreno-Dorado, F Javier; Ortega, María J; Vidal, Hilario; Gatica, José M; Massanet, Guillermo M; Guerra, Francisco M

    2015-07-01

    The use of a copper-iron mixed oxide as a heterogeneous catalyst for the efficient synthesis of ?-acyloxy-1,4-dioxanes and 1,4-dithianes employing t-butyl peroxyesters is reported. The preparation and characterization of the catalyst are described. The effect of the heteroatoms and a plausible mechanism are discussed. The method is operationally simple and involves low-cost starting materials affording products in good to excellent yields. PMID:26035339

  3. Structure and reactivity of copper iron pyrophosphate catalysts for selective oxidation of methane to formaldehyde and methanol

    Microsoft Academic Search

    Róbert Polnišer; Magdaléna Štolcová; Milan Hronec; Milan Mikula

    2011-01-01

    The structure of copper iron pyrophosphate catalysts prepared with various atomic ratios of metals and different pretreatment conditions was studied by using XRD, FT-IR, DR UV–vis and H2-TPR techniques. The preparation methods modify the phase composition, oxidation state and reducibility of the patterns. The catalytic properties in the selective oxidation of methane to formaldehyde and methanol were examined in both,

  4. Aluminium, iron and copper in human brain tissues donated to the Medical Research Council's Cognitive Function and Ageing Study.

    PubMed

    House, Emily; Esiri, Margaret; Forster, Gill; Ince, Paul G; Exley, Christopher

    2012-01-01

    Aluminium, iron and copper are all implicated in the aetiology of neurodegenerative diseases including Alzheimer's disease. However, there are very few large cohort studies of the content of these metals in aged human brains. We have used microwave digestion and TH GFAAS to measure aluminium, iron and copper in the temporal, frontal, occipital and parietal lobes of 60 brains donated to the Cognitive Function and Ageing Study. Every precaution was taken to reduce contamination of samples and acid digests to a minimum. Actual contamination was estimated by preparing a large number of (170+) method blanks which were interspersed within the full set of 700+ tissue digests. Subtraction of method blank values (MBV) from tissue digest values resulted in metal contents in all tissues in the range, MBV to 33 ?g g(-1) dry wt. for aluminium, 112 to 8305 ?g g(-1) dry wt. for iron and MBV to 384 ?g g(-1) dry wt. for copper. While the median aluminium content for all tissues was 1.02 ?g g(-1) dry wt. it was informative that 41 brains out of 60 included at least one tissue with an aluminium content which could be considered as potentially pathological (> 3.50 ?g g(-1) dry wt.). The median content for iron was 286.16 ?g g(-1) dry wt. and overall tissue iron contents were generally high which possibly reflected increased brain iron in ageing and in neurodegenerative disease. The median content for copper was 17.41 ?g g(-1) dry wt. and overall tissue copper contents were lower than expected for aged brains but they were commensurate with aged brains showing signs of neurodegenerative disease. In this study we have shown, in particular, the value of carrying out significant numbers of method blanks to identify unknown sources of contamination. When these values are subtracted from tissue digest values the absolute metal contents could be considered as conservative and yet they may still reflect aspects of ageing and neurodegenerative disease in individual brains. PMID:22045115

  5. JOURNAL DE PHYSIQUE Colloque C2, suppl6ment au no3, Tome 40, mars 1979, page C2-608 MOSSBAUER S?ECTROSCO?Y OF IRON IMPLANTED COPPER, S I LVER AND GOLD ALLOYS

    E-print Network

    Boyer, Edmond

    -anneals to study the migration of iron atoms within and away from the implanted layer is mentioned. Introduction?ECTROSCO?Y OF IRON IMPLANTED COPPER, S I LVER AND GOLD ALLOYS G. Longworth and R. aid Nuclear Physics Division (8 co ositions of copper-, siluer- and gold-iron alloys produced by 17pe implantation at a dose of 2x10

  6. The Variations of Glycolysis and TCA Cycle Intermediate Levels Grown in Iron and Copper Mediums of Trichoderma harzianum.

    PubMed

    Tavsan, Zehra; Ayar Kayali, Hulya

    2015-05-01

    The efficiency of optimal metabolic function by microorganism depends on various parameters, especially essential metal supplementation. In the present study, the effects of iron and copper metals on metabolism were investigated by determination of glycolysis and tricarboxylic acid (TCA) cycle metabolites' levels with respect to the metal concentrations and incubation period in Trichoderma harzianum. The pyruvate and citrate levels of T. harzianum increased up to 15 mg/L of copper via redirection of carbon flux though glycolysis by suppression of pentose phosphate pathway (PPP). However, the ?-ketoglutarate levels decreased at concentration higher than 5 mg/L of copper to overcome damage of oxidative stress. The fumarate levels correlated with the ?-ketoglutarate levels because of substrate limitation. Besides, in T. harzianum cells grown in various concentrations of iron-containing medium, the intracellular pyruvate, citrate, and ?-ketoglutarate levels showed positive correlation with iron concentration due to modifying of expression of glycolysis and TCA cycle enzymes via a mechanism involving cofactor or allosteric regulation. However, as a result of consuming of prior substrates required for fumarate production, its levels rose up to 10 mg/L. PMID:25805013

  7. Mixed messages in iron oxide–copper–gold systems of the Cloncurry district, Australia: insights from PIXE analysis of halogens and copper in fluid inclusions

    Microsoft Academic Search

    Timothy Baker; Roger Mustard; Bin Fu; Patrick J. Williams; Guoyi Dong; Louise Fisher; Geordie Mark; Chris G. Ryan

    2008-01-01

    Proterozoic rocks of the Cloncurry district in NW Queensland, Australia, are host to giant (tens to hundreds of square kilometers)\\u000a hydrothermal systems that include (1) barren regional sodic–calcic alteration, (2) granite-hosted hydrothermal complexes with\\u000a magmatic–hydrothermal transition features, and (3) iron oxide–copper–gold (IOCG) deposits. Fluid inclusion microthermometry\\u000a and proton-induced X-ray emission (PIXE) show that IOCG deposits and the granite-hosted hydrothermal complexes

  8. Reactivity of food phenols with iron and copper ions: binding, dioxygen activation and oxidation mechanisms.

    PubMed

    Nkhili, Ezzohra; Loonis, Michèle; Mihai, Simona; El Hajji, Hakima; Dangles, Olivier

    2014-06-01

    In this work, the affinity of common dietary phenols (gallic acid, caffeic acid, catechin, and rutin) for iron and copper ions was quantitatively investigated in neutral phosphate buffer as well as the reactivity of the complexes toward dioxygen. Contrasting behaviors were observed: because of the competing phosphate ions, Fe(III) binding is much slower than Fe(II) binding, which is rapidly followed by autoxidation of Fe(II) into Fe(III). With both ions, O2 consumption and H2O2 production are modest and the phenolic ligands are only slowly oxidized. By contrast, metal-phenol binding is fast with both Cu(I) and Cu(II). With Cu(I), O2 consumption and H2O2 production are very significant and the phenolic ligands are rapidly oxidized into a complex mixture of oligomers. The corresponding mechanism with Cu(II) is hampered by the preliminary rate-determining step of Cu(II) reduction by the phenols. The consequences of these findings for the stability and antioxidant activity of plant phenols are discussed. PMID:24700074

  9. Assessing Plasma Levels of Selenium, Copper, Iron and Zinc in Patients of Parkinson’s Disease

    PubMed Central

    Cheng, Xing; Wang, Jian-Yong; Hu, Bei-Lei; Zhang, Yan; Zhang, Xiong; Zhu, Jian-Hong

    2013-01-01

    Trace elements have been recognized to play an important role in the development of Parkinson’s disease (PD). However, it is difficult to precisely identify the relationship between these elements and the progression of PD because of an insufficient number of patients. In this study, quantifications of selenium (Se), copper (Cu), iron (Fe) and zinc (Zn) by atomic absorption spectrophotometry were performed in plasma from 238 PD patients and 302 controls recruited from eastern China, which is so far the largest cohort of PD patients and controls for measuring plasma levels of these elements. We found that plasma Se and Fe concentrations were significantly increased whereas Cu and Zn concentrations decreased in PD patients as compared with controls. Meanwhile, these four elements displayed differential changes with regard to age. Linear and logistic regression analyses revealed that both Fe and Zn were negatively correlated with age in PD patients. Association analysis suggests that lower plasma Se and Fe levels may reduce the risk for PD, whereas lower plasma Zn is probably a PD risk factor. Finally, a model was generated to predict PD patients based on the plasma concentrations of these four trace elements as well as other features such as sex and age, which achieved an accuracy of 80.97±1.34% using 10-fold cross-validation. In summary, our data provide new insights into the roles of Se, Cu, Fe and Zn in PD progression. PMID:24340079

  10. Timing of multiple hydrothermal events in the iron oxide-copper-gold deposits of the Southern Copper Belt, Carajás Province, Brazil

    NASA Astrophysics Data System (ADS)

    Moreto, Carolina P. N.; Monteiro, Lena V. S.; Xavier, Roberto P.; Creaser, Robert A.; DuFrane, S. Andrew; Melo, Gustavo H. C.; Delinardo da Silva, Marco A.; Tassinari, Colombo C. G.; Sato, Kei

    2015-06-01

    The Southern Copper Belt, Carajás Province, Brazil, hosts several iron oxide-copper-gold (IOCG) deposits, including Sossego, Cristalino, Alvo 118, Bacuri, Bacaba, Castanha, and Visconde. Mapping and U-Pb sensitive high-resolution ion microprobe (SHRIMP) IIe zircon geochronology allowed the characterization of the host rocks, situated within regional WNW-ESE shear zones. They encompass Mesoarchean (3.08-2.85 Ga) TTG orthogneiss, granites, and remains of greenstone belts, Neoarchean (ca. 2.74 Ga) granite, shallow-emplaced porphyries, and granophyric granite coeval with gabbro, and Paleoproterozoic (1.88 Ga) porphyry dykes. Extensive hydrothermal zones include albite-scapolite, biotite-scapolite-tourmaline-magnetite alteration, and proximal potassium feldspar, chlorite-epidote and chalcopyrite formation. U-Pb laser ablation multicollector inductively coupled mass spectrometry (LA-MC-ICP-MS) analysis of ore-related monazite and Re-Os NTIMS analysis of molybdenite suggest multiple Neoarchean (2.76 and 2.72-2.68 Ga) and Paleoproterozoic (2.06 Ga) hydrothermal events at the Bacaba and Bacuri deposits. These results, combined with available geochronological data from the literature, indicate recurrence of hydrothermal systems in the Southern Copper Belt, including 1.90-1.88-Ga ore formation in the Sossego-Curral ore bodies and the Alvo 118 deposit. Although early hydrothermal evolution at 2.76 Ga points to fluid migration coeval with the Carajás Basin formation, the main episode of IOCG genesis (2.72-2.68 Ga) is related to basin inversion coupled with Neoarchean (ca. 2.7 Ga) felsic magmatism. The data suggest that the IOCG deposits in the Southern Copper Belt and those in the Northern Copper Belt (2.57-Ga Salobo and Igarapé Bahia-Alemão deposits) do not share a common metallogenic evolution. Therefore, the association of all IOCG deposits of the Carajás Province with a single extensive hydrothermal system is precluded.

  11. Copper in diet

    MedlinePLUS

    Diet - copper ... Copper works with iron to help the body form red blood cells. It also helps keep the ... organ meats (kidneys, liver) are good sources of copper. Dark leafy greens, dried fruits such as prunes, ...

  12. Fractionation of fulvic acid by iron and aluminum oxides: influence on copper toxicity to Ceriodaphnia dubia

    USGS Publications Warehouse

    Smith, Kathleen S.; James F. Ranville; Emily K. Lesher; Daniel J. Diedrich; Diane M. McKnight; Ruth M. Sofield

    2014-01-01

    This study examines the effect on aquatic copper toxicity of the chemical fractionation of fulvic acid (FA) that results from its association with iron and aluminum oxyhydroxide precipitates. Fractionated and unfractionated FAs obtained from streamwater and suspended sediment were utilized in acute Cu toxicity tests on ,i>Ceriodaphnia dubia. Toxicity test results with equal FA concentrations (6 mg FA/L) show that the fractionated dissolved FA was 3 times less effective at reducing Cu toxicity (EC50 13 ± 0.6 ?g Cu/L) than were the unfractionated dissolved FAs (EC50 39 ± 0.4 and 41 ± 1.2 ?g Cu/L). The fractionation is a consequence of preferential sorption of molecules having strong metal-binding (more aromatic) moieties to precipitating Fe- and Al-rich oxyhydroxides, causing the remaining dissolved FA to be depleted in these functional groups. As a result, there is more bioavailable dissolved Cu in the water and hence greater potential for Cu toxicity to aquatic organisms. In predicting Cu toxicity, biotic ligand models (BLMs) take into account dissolved organic carbon (DOC) concentration; however, unless DOC characteristics are accounted for, model predictions can underestimate acute Cu toxicity for water containing fractionated dissolved FA. This may have implications for water-quality criteria in systems containing Fe- and Al-rich sediment, and in mined and mineralized areas in particular. Optical measurements, such as specific ultraviolet absorbance at 254 nm (SUVA254), show promise for use as spectral indicators of DOC chemical fractionation and inferred increased Cu toxicity.

  13. Perinatal iron and copper deficiencies alter neonatal rat circulating and brain thyroid hormone concentrations.

    PubMed

    Bastian, Thomas W; Prohaska, Joseph R; Georgieff, Michael K; Anderson, Grant W

    2010-08-01

    Copper (Cu), iron (Fe), and iodine/thyroid hormone (TH) deficiencies lead to similar defects in late brain development, suggesting that these micronutrient deficiencies share a common mechanism contributing to the observed derangements. Previous studies in rodents (postweanling and adult) and humans (adolescent and adult) indicate that Cu and Fe deficiencies affect the hypothalamic-pituitary-thyroid axis, leading to altered TH status. Importantly, however, relationships between Fe and Cu deficiencies and thyroidal status have not been assessed in the most vulnerable population, the developing fetus/neonate. We hypothesized that Cu and Fe deficiencies reduce circulating and brain TH levels during development, contributing to the defects in brain development associated with these deficiencies. To test this hypothesis, pregnant rat dams were rendered Cu deficient (CuD), FeD, or TH deficient from early gestation through weaning. Serum thyroxine (T(4)) and triiodothyronine (T(3)), and brain T(3) levels, were subsequently measured in postnatal d 12 (P12) pups. Cu deficiency reduced serum total T(3) by 48%, serum total T(4) by 21%, and whole-brain T(3) by 10% at P12. Fe deficiency reduced serum total T(3) by 43%, serum total T(4) by 67%, and whole-brain T(3) by 25% at P12. Brain mRNA analysis revealed that expression of several TH-responsive genes were altered in CuD or FeD neonates, suggesting that reduced TH concentrations were sensed by the FeD and CuD neonatal brain. These results indicate that at least some of the brain defects associated with neonatal Fe and Cu deficiencies are mediated through reductions in circulating and brain TH levels. PMID:20573724

  14. Perinatal Iron and Copper Deficiencies Alter Neonatal Rat Circulating and Brain Thyroid Hormone Concentrations

    PubMed Central

    Bastian, Thomas W.; Prohaska, Joseph R.; Georgieff, Michael K.; Anderson, Grant W.

    2010-01-01

    Copper (Cu), iron (Fe), and iodine/thyroid hormone (TH) deficiencies lead to similar defects in late brain development, suggesting that these micronutrient deficiencies share a common mechanism contributing to the observed derangements. Previous studies in rodents (postweanling and adult) and humans (adolescent and adult) indicate that Cu and Fe deficiencies affect the hypothalamic-pituitary-thyroid axis, leading to altered TH status. Importantly, however, relationships between Fe and Cu deficiencies and thyroidal status have not been assessed in the most vulnerable population, the developing fetus/neonate. We hypothesized that Cu and Fe deficiencies reduce circulating and brain TH levels during development, contributing to the defects in brain development associated with these deficiencies. To test this hypothesis, pregnant rat dams were rendered Cu deficient (CuD), FeD, or TH deficient from early gestation through weaning. Serum thyroxine (T4) and triiodothyronine (T3), and brain T3 levels, were subsequently measured in postnatal d 12 (P12) pups. Cu deficiency reduced serum total T3 by 48%, serum total T4 by 21%, and whole-brain T3 by 10% at P12. Fe deficiency reduced serum total T3 by 43%, serum total T4 by 67%, and whole-brain T3 by 25% at P12. Brain mRNA analysis revealed that expression of several TH-responsive genes were altered in CuD or FeD neonates, suggesting that reduced TH concentrations were sensed by the FeD and CuD neonatal brain. These results indicate that at least some of the brain defects associated with neonatal Fe and Cu deficiencies are mediated through reductions in circulating and brain TH levels. PMID:20573724

  15. Iron and copper accumulation in the brain of coxsackievirus-infected mice exposed to cadmium

    SciTech Connect

    Ilbaeck, N.-G. [Section of Infectious Diseases, Department of Medical Sciences, Uppsala University Hospital, S-751 85 Uppsala (Sweden) and Toxicology Division, National Food Administration, Uppsala (Sweden)]. E-mail: nils-gunnar.ilback@slv.se; Lindh, U. [Research in Metal Biology, Rudbeck Laboratory, Uppsala University, Uppsala (Sweden); Minqin, R. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore (Singapore); Friman, G. [Section of Infectious Diseases, Department of Medical Sciences, Uppsala University Hospital, S-751 85 Uppsala (Sweden); Watt, F. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore (Singapore)

    2006-11-15

    Cadmium (Cd) is a potentially toxic metal widely distributed in the environment and known to cause adverse health effects in humans. During coxsackievirus infection, the concentrations of essential and nonessential trace elements (e.g., iron (Fe), copper (Cu), and Cd) change in different target organs of the infection. Fe and Cu are recognized cofactors in host defence reactions, and Fe is known to be associated with certain pathological conditions of the brain. However, whether nonessential trace elements could influence the balance of essential trace elements in the brain is unknown. In this study the brain Fe, Cu, and Cd contents were measured through inductively coupled plasma mass spectrometry and their distributions determined by nuclear microscopy in the early phase (day 3) of coxsackievirus B3 (CB3) infection in nonexposed and in Cd-exposed female Balb/c mice. In CB3 infection the brain is a well-known target that has not been studied with regard to trace element balance. The brain concentration of Cu compared with that of noninfected control mice was increased by 9% (P<0.05) in infected mice not exposed to Cd and by 10% (not significant) in infected Cd-exposed mice. A similar response was seen for Fe, which in infected Cd-exposed mice, compared to noninfected control mice, tended to increase by 16%. Cu showed an even tissue distribution, whereas Fe was distributed in focal deposits. Changes in Cd concentration in the brain of infected mice were less consistent but evenly distributed. Further studies are needed to define whether the accumulation and distribution of trace elements in the brain have an impact on brain function.

  16. Biochemical lesions in copper-deficient rats caused by secondary iron deficiency. Derangement of protein synthesis and impairment of energy metabolism

    PubMed Central

    Weisenberg, Emil; Halbreich, Avraham; Mager, Jacob

    1980-01-01

    Severe copper deficiency was induced in rats by rearing nursing dams and their offsprings on a semisynthetic diet comprising all the requisite nutrients and trace metals except copper. The copper-deprived rats exhibited growth retardation, severe anaemia, loss of caeruloplasmin, decrease of cytochrome oxidase, accumulation of salt-soluble collagen and a drastic decrease in iron in plasma and liver. Apart from these characteristic signs of deficiency, a marked inhibition of protein synthesis was found to occur both in vivo and in cell-free liver preparations. The curtailed ability to carry out endogenously coded amino acid incorporation into protein contrasted with the unimpaired poly(U)-acid-directed phenylalanine polymerization. This inhibition pattern, as well as the attendant disaggregation of the liver polyribosomes, suggested that the primary biosynthetic lesion was located at the stage of peptide-chain initiation. Concurrently with this alteration there was a pronounced depletion of the hepatic ATP content, associated with a parallel depression of mitochondrial respiration and an enhancement of ATPase activity. Supplementation of the copper-deficient diet with a 2–4-fold excess of iron (relative to the standard diet) prevented growth retardation and anaemia and restored normal energy metabolism, as well as unimpaired protein-synthesizing capacity. The conclusion that these disturbances were primarily determined by the secondary iron deficiency was also borne out by the finding that similar alterations occurred in rats maintained on a copper-sufficient but iron-deficient diet. On the other hand, the iron-fortified diet failed to reverse the other signs of copper deficiency, namely the loss of caeruloplasmin, the diminished rate of cytochrome oxidase and the increase of soluble collagen. The interrelations between the various biochemical lesions induced by deprivation of copper or iron are discussed and the possible role of ATP depletion in determining the derangement of protein synthesis is considered. PMID:6258558

  17. Preconcentration of iron (III), cobalt (II) and copper (II) nitroso-R complexes on tetradecyldimethylbenzylammonium iodide-naphthalene adsorbent

    Microsoft Academic Search

    Bal K. Puri; Sanjay Balani

    1995-01-01

    Iron, cobalt and copper form coloured water soluble anionic complexes with disodium 1-nitroso-2-naphthol-3-6-disulphonate (nitroso R-salt). The anionic complex is retained quantitatively as a water insoluble neutral ion associated complex (M-nitroso R-TDBA) on tetradecyldimethylbenzylammonium iodide on naphthalene (TDBA+I?-naphthalene) packed column in the pH range of: Fe(III): 3.1–6.5, Co: 3.4–8.5 and Cu 5.9–8.0 when their solutions are passed individually over this adsorbent

  18. Auger electron spectroscopy study of surface segregation in the binary alloys copper-1 atomic percent indium, copper-2 atomic percent tin, and iron-6.55 atomic percent silicon

    NASA Technical Reports Server (NTRS)

    Ferrante, J.

    1973-01-01

    Auger electron spectroscopy was used to examine surface segregation in the binary alloys copper-1 at. % indium, copper-2 at. % tin and iron-6.55 at. % silicon. The copper-tin and copper-indium alloys were single crystals oriented with the /111/ direction normal to the surface. An iron-6.5 at. % silicon alloy was studied (a single crystal oriented in the /100/ direction for study of a (100) surface). It was found that surface segregation occurred following sputtering in all cases. Only the iron-silicon single crystal alloy exhibited equilibrium segregation (i.e., reversibility of surface concentration with temperature) for which at present we have no explanation. McLean's analysis for equilibrium segregation at grain boundaries did not apply to the present results, despite the successful application to dilute copper-aluminum alloys. The relation of solute atomic size and solubility to surface segregation is discussed. Estimates of the depth of segregation in the copper-tin alloy indicate that it is of the order of a monolayer surface film.

  19. Effects of sulfur, zinc, iron, copper, manganese, and boron applications on sunflower yield and plant nutrient concentration

    SciTech Connect

    Hilton, B.R.; Zubriski, J.C.

    1985-01-01

    Sulfur, zinc, iron, copper, manganese, and boron application did not affect the seed yield or oil percentage of sunflower (Helianthus annuus L.) on both dryland and irrigated soils in North Dakota in 1981. Field averages indicated significant Zn, Mn, and B uptake by sunflower at the 12-leaf stage as a result of fertilization with these elements. Increased Zn uptake was also observed in the uppermost mature leaf at anthesis from zinc fertilization. Although sunflower yield from boron fertilization was not significantly different from the check, a trend was observed in which boron fertilization seemed to decrease sunflower yield. Sunflower yields from the boron treatment were the lowest out of seven treatments in three out of four fields. Also, sunflower yield from the boron treatment was significantly lower than both iron and sulfur treatments when all fields were combined.

  20. Maternal iron supplementation attenuates the impact of perinatal copper deficiency but does not eliminate hypotriiodothyroninemia nor impaired sensorimotor development.

    PubMed

    Bastian, Thomas W; Lassi, Katie C; Anderson, Grant W; Prohaska, Joseph R

    2011-11-01

    Copper, iron and iodine/thyroid hormone (TH) deficiencies disrupt brain development. Neonatal Cu deficiency causes Fe deficiency and may impact thyroidal status. One purpose of these studies was to determine the impact of improved iron status following Cu deficiency by supplementing the diet with iron. Cu deficiency was produced in pregnant Holtzman [Experiment 1 (Exp. 1)] or Sprague-Dawley [Experiment 2 (Exp. 2)] rats using two different diets. In Exp. 2, dietary Fe content was increased from 35 to 75 mg/kg according to NRC guidelines for reproduction. Cu-deficient (CuD) Postnatal Day 24 (P24) rats from both experiments demonstrated lower hemoglobin, serum Fe and serum triiodothyronine (T3) concentrations. However, brain Fe was lower only in CuD P24 rats in Exp. 1. Hemoglobin and serum Fe were higher in Cu adequate (CuA) P24 rats from Exp. 2 compared to Exp. 1. Cu- and TH-deficient rats from Exp. 2 exhibited a similar sensorimotor functional deficit following 3 months of repletion. Results suggest that Cu deficiency may impact TH status independent of its impact on iron biology. Further research is needed to clarify the individual roles for Cu, Fe and TH in brain development. PMID:21239157

  1. Maternal iron supplementation attenuates the impact of perinatal copper deficiency but does not eliminate hypotriiodothyroninemia nor impaired sensorimotor development

    PubMed Central

    Bastian, Thomas W.; Lassi, Katie C.; Anderson, Grant W.; Prohaska, Joseph R.

    2012-01-01

    Copper (Cu), iron (Fe), and iodine/thyroid hormone (TH) deficiencies disrupt brain development. Neonatal Cu deficiency causes Fe deficiency and may impact thyroidal status. One purpose of these studies was to determine the impact of improved iron status following Cu deficiency by supplementing the diet with iron. Cu deficiency was produced in pregnant Holtzman (Exp. 1) or Sprague Dawley (Exp. 2) rats using two different diets. In Exp. 2, dietary Fe content was increased from 35 to 75 mg/kg according to NRC guidelines for reproduction. Cu deficient (CuD) postnatal day 24 (P24) rats from both experiments demonstrated lower hemoglobin, serum Fe, and serum triiodothyronine (T3) concentrations. However, brain Fe was lower only in CuD P24 rats in Exp. 1. Hemoglobin and serum Fe were higher in Cu adequate (CuA) P24 rats from Exp. 2 compared to Exp. 1. Cu and TH deficient rats from Exp. 2 exhibited a similar sensorimotor functional deficit following three months of repletion. Results suggest that Cu deficiency may impact TH status independent of its impact on iron biology. Further research is needed to clarify the individual roles for Cu, Fe, and TH in brain development. PMID:21239157

  2. Bosonics in the copper and iron based high transition temperature superconductors

    NASA Astrophysics Data System (ADS)

    Niestemski, Francis Charles

    It has been long established that the phenomenon of superconductivity is administered by lattice deformations (phonons) which act to pair electrons into spinless bosons free to condense into a coherent ground state. This superconducting phase is protected up to a critical temperature above which thermal fluctuations are potent enough to destroy the resistance free phase. The strength of this phonon mediation has been calculated by strong coupling theory and found to be capable of accommodating pairing up to near 40 K. So with the advent of copper-oxide (cuprate) superconductors boasting transitions temperatures exceeding 90 K it was clear that these material represented a new breed of superconducting physics. More than twenty years after the initial discovery of these high-transition temperatures the most basic questions are yet to be answered, the most fundamental of which is by what mechanism does pairing occur? The field splits between those who feel that a boson mediator is still necessary to act as the virtual glue which binds electrons into cooper pairs while others insist that really the Coulomb force alone is enough to induce pairing physics. Even within the boson-seeker community there is no consensus on what particular type of boson is contained in this system whether it be a lattice excitation or spin excitation. This answer has been clouded by previous experimental results on the hole-doped cuprates which have made strong cases for every scenario rendering them largely inconclusive. For this answer though it is possible to explore materials that have not yet been clouded by conflicting results by performing the first high resolution ultra-high-vacuum low-temperature scanning tunneling microscopy (STM) study of an electron-doped cuprate. A distinct and unambiguous bosonic mode is found at energy near 10.5 meV. Through comparison with other experimental data it is found that this mode does not fit the characteristics of a phonon. It is found, through comparison with neutron scattering experiments on the same sample, that this mode is consistent with a spin collective mode. Further more it is found that this mode is linked with the strength of superconductivity nominating it as the possible electron pairing mechanism. Doping and temperature dependence studies are performed to investigate this possibility. Finally the same procedures developed can be applied to the newly discovered iron based superconductors which may represent yet another type of new superconductor physics. Initial results on the first bosonic mode STM study of SrFe 2-xCoxAs 2 and BaFe2-xCo xAs2 are presented.

  3. Copper and Iron Determination with [ N , N ?Bis(salicylidene)-2,2?-dimethyl-1,3-propanediaminato] in Edible Oils Without Digestion

    Microsoft Academic Search

    Eda Köse Baran; Sema Ba?dat Ya?ar

    2010-01-01

    A new method for the determination of copper(II) and iron(III) in liquid edible oils which does not require a digestion step\\u000a was developed. The suggested method involves extraction of metals with [N,N?-bis(salicylidene)-2,2?-dimethyl-1,3-propanediaminato] (LDM) followed by flame atomic absorption spectrometry measurement.\\u000a As a first step, metal complexes of copper(II) and iron(III) ions with LDM were investigated spectrophotometrically. After\\u000a the analytical properties

  4. Effect of excessive dietary fluoride on nutrient digestibility and retention of iron, copper, zinc, and manganese in growing pigs.

    PubMed

    Tao, X; Xu, Z R; Wang, Y Z

    2005-11-01

    Ninety-six crossbred growing pigs were used to evaluate the effects of fluoride levels on growth performance, nutrient digestibility, and the retention of minerals in tissues. Four dietary treatments were formulated by supplementing fluorine (as NaF) to a corn-soybean basal diet (39.75 mg/kg F) to provide the following added fluorine levels: 0, 50, 100, and 150 mg/kg fluorine. The results showed pigs of the 100 and 150 mg/kg fluorine-added groups had decreased average daily gain (ADG) and increased feed gain ratio (F/G) compared to the control (p < 0.05). Apparent digestibility of protein and calcium in 100 and 150 mg/kg fluorine-treated groups was significantly lower than that of the control (p < 0.05). On the other hand, iron, copper, zinc, and manganese levels in most tissues of the 100 and 150 mg/kg fluorine groups were markedly changed compared to the control (p < 0.05). However, growth performance, nutrient digestibility, and mineral concentrations in all tissues of pigs were not significantly affected by the addition of 50 mg/kg fluorine (p > 0.05). Thus, this study suggested that excess fluoride levels could decrease growth performance and change the retention of iron, copper, zinc, and manganese in pigs. PMID:16217139

  5. Concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium, and lead in the liver and kidneys of dogs according to age, gender, and the occurrence of chronic kidney disease

    PubMed Central

    Mainzer, Barbara; Lahrssen-Wiederholt, Monika; Schafft, Helmut; Palavinskas, Richard; Breithaupt, Angele; Zentek, Jürgen

    2015-01-01

    This study was conducted to measure the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se), and lead (Pb) in canine liver, renal cortex, and renal medulla, and the association of these concentrations with age, gender, and occurrence of chronic kidney disease (CKD). Tissues from 50 dogs were analyzed using inductively coupled plasma mass spectrometry. Cu, Zn, and Mn levels were highest in the liver followed by the renal cortex and renal medulla. The highest Sr, Cd, and Se concentrations were measured in the renal cortex while lower levels were found in the renal medulla and liver. Female dogs had higher tissue concentrations of Sr (liver and renal medulla), Cd (liver), Zn (liver and renal cortex), Cr (liver, renal cortex, and renal medulla), and Pb (liver) than male animals. Except for Mn and Sb, age-dependent variations were observed for all element concentrations in the canine tissues. Hepatic Cd and Cr concentrations were higher in dogs with CKD. In conclusion, the present results provide new knowledge about the storage of specific elements in canine liver and kidneys, and can be considered important reference data for diagnostic methods and further investigations. PMID:25234328

  6. Determination of iron and copper in seawater at pH 1.7 with a new commercially available chelating resin, NTA Superflow

    Microsoft Academic Search

    Maeve C. Lohan; Ana M. Aguilar-Islas; Robert P. Franks; Kenneth W. Bruland

    2005-01-01

    The use of a commercially available chelating resin with NTA-type functional groups for concentration of trace metals from seawater is described. Trace metal recoveries from this NTA Superflow chelating resin are pH dependent. At a pH of ?2 only iron(III) and copper are quantitatively recovered from the resin. Iron(II) cannot be quantitatively recovered from this resin below a pH of

  7. Origin of fluids in iron oxide–copper–gold deposits: constraints from ? 37 Cl, 87 Sr\\/ 86 Sr i and Cl\\/Br

    Microsoft Academic Search

    Massimo Chiaradia; Dave Banks; Robert Cliff; Robert Marschik; Antoine de Haller

    2006-01-01

    The origin of the hypersaline fluids (magmatic or basinal brine?), associated with iron oxide (Cu–U–Au–REE) deposits, is controversial. We report the first chlorine and strontium isotope data combined with Cl\\/Br ratios of fluid inclusions from selected iron oxide–copper–gold (IOCG) deposits (Candelaria, Raúl–Condestable, Sossego), a deposit considered to represent a magmatic end member of the IOCG class of deposit (Gameleira), and

  8. Iron

    MedlinePLUS

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  9. Copper and iron isotope fractionation during weathering and pedogenesis: Insights from saprolite profiles

    NASA Astrophysics Data System (ADS)

    Liu, Sheng-Ao; Teng, Fang-Zhen; Li, Shuguang; Wei, Gang-Jian; Ma, Jing-Long; Li, Dandan

    2014-12-01

    Iron and copper isotopes are useful tools to track redox transformation and biogeochemical cycling in natural environment. To study the relationships of stable Fe and Cu isotopic variations with redox regime and biological processes during weathering and pedogenesis, we carried out Fe and Cu isotope analyses for two sets of basalt weathering profiles (South Carolina, USA and Hainan Island, China), which formed under different climatic conditions (subtropical vs. tropical). Unaltered parent rocks from both profiles have uniform ?56Fe and ?65Cu values close to the average of global basalts. In the South Carolina profile, ?56Fe values of saprolites vary from -0.01‰ to 0.92‰ in the lower (reduced) part and positively correlate with Fe3+/?Fe (R2 = 0.90), whereas ?65Cu values are almost constant. By contrast, ?56Fe values are less variable and negatively correlate with Fe3+/?Fe (R2 = 0.88) in the upper (oxidized) part, where large (4.85‰) ?65Cu variation is observed with most samples enriched in heavy isotopes. In the Hainan profile formed by extreme weathering under oxidized condition, ?56Fe values vary little (0.05-0.14‰), whereas ?65Cu values successively decrease from 0.32‰ to -0.12‰ with depth below 3 m and increase from -0.17‰ to 0.02‰ with depth above 3 m. Throughout the whole profile, ?65Cu positively correlate with Cu concentration and negatively correlate with the content of total organic carbon (TOC). Overall, the contrasting Fe isotopic patterns under different redox conditions suggest redox states play the key controls on Fe mobility and isotope fractionation. The negative correlation between ?56Fe and Fe3+/?Fe in the oxidized part of the South Carolina profile may reflect addition of isotopically light Fe. This is demonstrated by leaching experiments, which show that Fe mineral pools extracted by 0.5 N HCl, representing poorly-crystalline Fe (hydr)-oxides, are enriched in light Fe isotopes. The systematic Cu isotopic variation in the Hainan profile reflects desorption and downward transport of isotopically heavy Cu, leaving the organically-bound Cu enriched in light isotope as supported by the negative correlation of ?65Cu with TOC (R2 = 0.88). The contrasting (mostly positive vs. negative) Cu isotopic signatures in the upper parts of these two profiles can be attributed to the different climatic conditions, e.g., high rainfall at a tropical climate in Hainan favors desorption and the development of organism, whereas relatively dry climate in South Carolina favors Cu re-precipitation from soil solutions and adsorption onto Fe (hydr)-oxides. Our results highlight the potential applications of Fe and Cu isotopes as great tracers of redox condition, ancient climate and biological cycling during chemical weathering and pedogenic translocation.

  10. Iron, copper, zinc and bromine mapping in cirrhotic liver slices from patients with hemochromatosis studied by microscopic synchrotron radiation X-ray fluorescence analysis in continuous scanning mode

    Microsoft Academic Search

    W. Osterode; G. Falkenberg; R. Höftberger; F. Wrba

    2007-01-01

    Iron (Fe) and copper (Cu) are essential metals in physiological cell metabolism. While Fe is easy to determine biochemically in histological slices, Cu and zinc (Zn) distribution is frequently critical in confirming the presence of an overload in disturbed Fe\\/Cu metabolism. To analyze Fe, Cu and Zn in a near histological resolution, energy dispersive microscopic synchrotron radiation X-ray fluorescence was

  11. Sulfur dioxide removal from flue gases by supported copper and iron absorbents

    SciTech Connect

    Melson, G.A.

    1988-01-01

    This project was initiated in response to a need to address the problem of attrition for copper oxide/alumina sorbents for the PETC fluidized bed copper oxide process. The attrition problem is a major drawback to the economic feasibility of the process. Previous attempts to reduce sorbent attrition focused on engineering modifications; however, it was proposed that the method of impregnation and pre-treatment of a copper oxide/alumina sorbent may have a significant effect on the reactivity and stability of the sorbent and thus the attrition rate. Prepared sorbents would be characterized by a variety of techniques. Sorption of sulfur dioxide from simulated flue gas mixtures and regeneration of the sorbents with hydrogen and methane would be studied, particularly by thermogravimetric techniques. Evaluation of the rate of attrition for the prepared sorbents would be made. 5 refs., 9 figs.

  12. Insight into bio-metal interface formation in vacuo: interplay of S-layer protein with copper and iron.

    PubMed

    Makarova, Anna A; Grachova, Elena V; Neudachina, Vera S; Yashina, Lada V; Blüher, Anja; Molodtsov, Serguei L; Mertig, Michael; Ehrlich, Hermann; Adamchuk, Vera K; Laubschat, Clemens; Vyalikh, Denis V

    2015-01-01

    The mechanisms of interaction between inorganic matter and biomolecules, as well as properties of resulting hybrids, are receiving growing interest due to the rapidly developing field of bionanotechnology. The majority of potential applications for metal-biohybrid structures require stability of these systems under vacuum conditions, where their chemistry is elusive, and may differ dramatically from the interaction between biomolecules and metal ions in vivo. Here we report for the first time a photoemission and X-ray absorption study of the formation of a hybrid metal-protein system, tracing step-by-step the chemical interactions between the protein and metals (Cu and Fe) in vacuo. Our experiments reveal stabilization of the enol form of peptide bonds as the result of protein-metal interactions for both metals. The resulting complex with copper appears to be rather stable. In contrast, the system with iron decomposes to form inorganic species like oxide, carbide, nitride, and cyanide. PMID:25736576

  13. Optimized photorefractive barium titanate

    NASA Astrophysics Data System (ADS)

    Warde, Cardinal; Jenssen, Hans P.

    1992-03-01

    The goal of this research program was to investigate new and modified crystal-growth techniques that would lead to high-optical-quality BaTiO3 with increased photorefractive speed and sensitivity. The research program consisted of four parts: (1) feed material purification; (2) crystal growth by the top-seeded-solution technique as well as by a barium borate flux technique; (3) new furnace design studies; and (4) photorefractive characterization experiments. Iron and nickel-doped BaTiO3 crystals were grown under the program. BaTiO3 is a promising photorefractive material due to its large electrooptic coefficient and excellent self-pumped phase conjugation. Our furnaces were limited by certain design and operating characteristics, and crystals grown in these furnaces were easily contaminated by the furnace itself. Two new furnaces, cylindrical and octagonal furnaces, were developed with commercially available parts that are cleaner, more mechanically reproducible, more uniform in temperature and more responsive to control action through reduced thermal mass. The two furnaces are equipped with precise computer control of the pulling and rotation system. The cylindrical furnace was found to be susceptible to cracking due to expansion when heated and to shrinkage after heating. To prevent cracking, expansion joints were provided and the insulation set was made of flat plates set up in an octagonal pattern.

  14. Iron, copper, and manganese complexes with in vitro superoxide dismutase and/or catalase activities that keep Saccharomyces cerevisiae cells alive under severe oxidative stress.

    PubMed

    Ribeiro, Thales P; Fernandes, Christiane; Melo, Karen V; Ferreira, Sarah S; Lessa, Josane A; Franco, Roberto W A; Schenk, Gerhard; Pereira, Marcos D; Horn, Adolfo

    2015-03-01

    Due to their aerobic lifestyle, eukaryotic organisms have evolved different strategies to overcome oxidative stress. The recruitment of some specific metalloenzymes such as superoxide dismutases (SODs) and catalases (CATs) is of great importance for eliminating harmful reactive oxygen species (hydrogen peroxide and superoxide anion). Using the ligand HPClNOL {1-[bis(pyridin-2-ylmethyl)amino]-3-chloropropan-2-ol}, we have synthesized three coordination compounds containing iron(III), copper(II), and manganese(II) ions, which are also present in the active site of the above-noted metalloenzymes. These compounds were evaluated as SOD and CAT mimetics. The manganese and iron compounds showed both SOD and CAT activities, while copper showed only SOD activity. The copper and manganese in vitro SOD activities are very similar (IC50~0.4 ?mol dm(-3)) and about 70-fold higher than those of iron. The manganese compound showed CAT activity higher than that of the iron species. Analyzing their capacity to protect Saccharomyces cerevisiae cells against oxidative stress (H2O2 and the O2(•-) radical), we observed that all compounds act as antioxidants, increasing the resistance of yeast cells mainly due to a reduction of lipid oxidation. Especially for the iron compound, the data indicate complete protection when wild-type cells were exposed to H2O2 or O2(•-) species. Interestingly, these compounds also compensate for both superoxide dismutase and catalase deficiencies; their antioxidant activity is metal ion dependent, in the order iron(III)>copper(II)>manganese(II). The protection mechanism employed by the complexes proved to be independent of the activation of transcription factors (such as Yap1, Hsf1, Msn2/Msn4) and protein synthesis. There is no direct relation between the in vitro and the in vivo antioxidant activities. PMID:25511255

  15. Removal of copper and iron by polyurethane foam column in FIA system for the determination of nickel in pierced ring.

    PubMed

    Vongboot, Monnapat; Suesoonthon, Monrudee

    2015-01-01

    Polyurethane foam (PUF) mini-column was used to eliminate copper and iron for the determination of nickel in pierced rings. The PUF mini-column was connected to FIA system for on-line sorption of copper and iron in complexes form of CuSCN(+) and FeSCN(2+). For this season, the acid solution containing a mixture of Ni(II), Fe(III), Cu(II) and SCN(-) ions was firstly flew into the PUF column. Then, the percolated solution which Fe(III) and Cu(II) ions is separated from analysis was injected into FIA system to react with 4-(2-pyridylazo) resorcinol (PAR) reagent in basic condition which this method is called pH gradient technique. The Ni-PAR complexes obtained were measured theirs absorbance at 500 nm by UV visible spectrophotometer. In this study, it was found that Cu(II) and Fe(III) were completely to form complexes with 400 mmol/L KSCN and entirely to eliminate in acidic condition at pH 3.0. In the optimum condition of these experiments, the method provided the linear relationship between absorbance and the concentration of Ni(II) in the range from 5.00 to 30.00 mg/L. Linear equation is y=0.0134x+0.0033 (R(2)=0.9948). Precision, assessed in the term of the relative standard deviation, RSD, and accuracy for multiple determinations obtained in values of 0.77-1.73% and 97.4%, respectively. The level of an average amount of Ni(II) in six piercing rings was evaluated to be 14.78 mg/g. PMID:25281109

  16. Selective elution of copper and iron cyanide complexes from ion exchange resins using saline solutions

    Microsoft Academic Search

    G. C Lukey; J. S. J van Deventer; D. C Shallcross

    2000-01-01

    Numerous reagents for the elution of metal cyanide complexes from ion exchange resins have been proposed previously. However, a simple and cost-effective elution procedure has not been developed that is able to selectively strip metal cyanide complexes from the resin. The results of the current study show that highly saline solutions can be used to selectively elute copper cyanide and

  17. Interactions of free copper (II) ions alone or in complex with iron (III) ions with erythrocytes of marine fish Dicentrarchus labrax.

    PubMed

    Labieniec, Magdalena; Milowska, Katarzyna; Balcerczyk, Aneta; Rucinska, Agata; Sadowska, Magdalena; Jokiel, Marta; Brichon, Gerard; Gabryelak, Teresa

    2009-09-01

    As a consequence of human activity, various toxicants - especially metal ions - enter aquatic ecosystems and many fish are exposed to considerable levels. As the free ion and in some complexes, there is no doubt that copper promotes damage to cellular molecules and structures through radical formation. Therefore, we have investigated the influence of copper uptake by the red blood of the sea bass (Dicentrarchus labrax), and its oxidative action and effects on cells in the presence of complexed and uncomplexed Fe3+ ions. Erythrocytes were exposed to various concentrations of CuSO4, Fe(NO3)3, and K3Fe(CN)6 for up to 5h, and the effects of copper ions alone and in the combination with iron determined. The results show that inside the cells cupric ion interacts with hemoglobin, causing methemoglobin formation by direct electron transfer from heme Fe2+ to Cu2+. Potassium ferricyanide as a source of complexed iron decreases Met-Hb formation induced by copper ions unlike Fe(NO3)3. We also found that incubation of fish erythrocytes with copper increased hemolysis of cells. But complexed and uncomplexed iron protected the effect of copper. CuSO4 increased the level of lipid peroxidation and a protective effect on complexed iron was observed. Incubation of erythrocytes with copper ions resulted in the loss of a considerable part of thiol content at 10 and 20 microM. This effect was decreased by potassium ferricyanide and Fe(NO3)3 only after 1 and 3h of incubation. The level of nuclear DNA damage assayed by comet assay showed that 20 microM CuSO4 as well as 20 microM Fe(NO3)3 and 10 mM K3Fe(CN)6 induce single- and double-strand breaks. The lower changes were observed after the exposure of cells to K3Fe(CN)6. The data suggest that complexed iron can act protectively against copper ions in contrast to Fe(NO3)3. PMID:19524693

  18. Structure, insertion electrochemistry, and magnetic properties of a new type of substitutional solid solutions of copper, nickel, and iron hexacyanoferrates/hexacyanocobaltates.

    PubMed

    Widmann, Antje; Kahlert, Heike; Petrovic-Prelevic, Irena; Wulff, Harm; Yakhmi, J V; Bagkar, Nitin; Scholz, Fritz

    2002-11-01

    Substitutional solid solutions of metal hexacyanometalates in which low-spin iron(III) and cobalt(III) ions populate the carbon-coordinated sites were synthesized and studied by powder diffraction including Rietveld refinement, cyclic voltammetry of immobilized microparticles, diffuse reflection vis-spectrometry, and magnetization techniques. The continuous solid solution series of potassium copper(II), potassium nickel(II), and iron(III) [(hexacyanoferrate(III))(1-x)(hexacyanocobaltate(III))(x)] show that the substitution of low-spin iron(III) by cobalt(III) in the hexacyanometalate units more strongly affects the formal potentials of the nitrogen-coordinated copper(II) and high-spin iron(III) ions than those of the remaining low-spin iron(III) ions. In the case of copper(II) and iron(III) [(hexacyanoferrate(III))(1-x)(hexacyanocobaltate(III))(x)] the peak currents decrease much more than can be explained by stoichiometry, indicating that the charge propagation is slowed by the substitution of low-spin iron(III) by cobalt(III). The Rietveld refinement of all compounds confirmed the structure initially proposed by Keggin for Prussian blue and contradicts the structure described later by Ludi. The dependencies of lattice parameters on composition exhibit in all series of solid solutions studied similar, although small, deviations from ideality, which correlate with the electrochemical behavior. Finally, a series of solid solutions of the composition KNi(0.5)(II)Cu(0.5)(II)[Fe(III)(CN)(6)](1-x)[Co(III)(CN)(6)](x), where both the nitrogen- and carbon-coordinated metal ions are mixed populated and were synthesized and characterized. These are the first examples of solid solutions of metal hexacyanometalates with four different metal ions, where both the nitrogen- and the carbon-coordinated sites possess a mixed population. PMID:12401075

  19. The determination of aluminum, copper, iron, and lead in glycol formulations by atomic absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Initial screening tests and the results obtained in developing procedures to determine Al, Cu, Fe, and Pb in glycol formulations are described. Atomic absorption completion was selected for Cu, Fe and Pb, and after comparison with emission spectroscopy, was selected for Al also. Before completion, carbon, iron, and lead are extracted with diethyl dithio carbamate (DDC) into methyl isobutyl ketone (MIBK). Aluminum was also extracted into MIBK using 8-hydroxyquinoline as a chelating agent. As little as 0.02 mg/l carbon and 0.06 mg/l lead or iron may be determined in glycol formulations. As little as 0.3 mg/l aluminum may be determined.

  20. Laser-initiated combustion studies of selected aluminum, copper, iron, and nickel alloys

    NASA Technical Reports Server (NTRS)

    Bransford, J. W.; Clark, A. F.

    1981-01-01

    The results of combustion studies at atmospheric pressure on ten metal alloys are presented. The alloys studied were aluminum alloys 1100, 2219, 6061, and tensile-50; 304, 347 and 21-6-9 stainless steel; inconel 600; beryllium copper and a bronze. It was found that once ignition was achieved all alloys would generally burn to completion. The overall combustion process appears to obey a first order rate process. Preliminary conclusions are presented along with recommendations for future work.

  1. Rosette iron deficiency transcript and microRNA profiling reveals links between copper and iron homeostasis in Arabidopsis thaliana

    PubMed Central

    Waters, Brian M.; Stein, Ricardo J.

    2012-01-01

    Iron (Fe) is an essential plant micronutrient, and its deficiency limits plant growth and development on alkaline soils. Under Fe deficiency, plant responses include up-regulation of genes involved in Fe uptake from the soil. However, little is known about shoot responses to Fe deficiency. Using microarrays to probe gene expression in Kas-1 and Tsu-1 ecotypes of Arabidopsis thaliana, and comparison with existing Col-0 data, revealed conserved rosette gene expression responses to Fe deficiency. Fe-regulated genes included known metal homeostasis-related genes, and a number of genes of unknown function. Several genes responded to Fe deficiency in both roots and rosettes. Fe deficiency led to up-regulation of Cu,Zn superoxide dismutase (SOD) genes CSD1 and CSD2, and down-regulation of FeSOD genes FSD1 and FSD2. Eight microRNAs were found to respond to Fe deficiency. Three of these (miR397a, miR398a, and miR398b/c) are known to regulate transcripts of Cu-containing proteins, and were down-regulated by Fe deficiency, suggesting that they could be involved in plant adaptation to Fe limitation. Indeed, Fe deficiency led to accumulation of Cu in rosettes, prior to any detectable decrease in Fe concentration. ccs1 mutants that lack functional Cu,ZnSOD proteins were prone to greater oxidative stress under Fe deficiency, indicating that increased Cu concentration under Fe limitation has an important role in oxidative stress prevention. The present results show that Cu accumulation, microRNA regulation, and associated differential expression of Fe and CuSOD genes are coordinated responses to Fe limitation. PMID:22962679

  2. Elevated copper in the amyloid plaques and iron in the cortex are observed in mouse models of Alzheimer’s disease that exhibit neurodegeneration

    PubMed Central

    Bourassa, Megan W.; Leskovjan, Andreana C.; Tappero, Ryan V.; Farquhar, Erik R.; Colton, Carol A.; Van Nostrand, William E.; Miller, Lisa M.

    2014-01-01

    BACKGROUND In Alzheimer’s disease (AD), alterations in metal homeostasis, including the accumulation of metal ions in the plaques and an increase of iron in the cortex, have been well documented but the mechanisms involved are poorly understood. OBJECTIVE In this study, we compared the metal content in the plaques and the iron speciation in the cortex of three mouse models, two of which show neurodegeneration (5xFAD and Tg-SwDI/NOS2?/? (CVN) and one that shows very little neurodegeneration (PSAPP). METHODS The Fe, Cu, and Zn contents and speciation were determined using synchrotron X-ray fluorescence microscopy (XFM) and X-ray absorption spectroscopy (XAS), respectively. RESULTS In the mouse models with reported significant neurodegeneration, we found that plaques contained ~25% more copper compared to the PSAPP mice. The iron content in the cortex increased at the late stage of the disease in all mouse models, but iron speciation remains unchanged. CONCLUSIONS The elevation of copper in the plaques and iron in the cortex is associated with AD severity, suggesting that these redox-active metal ions may be inducing oxidative damage and directly influencing neurodegeneration. PMID:24926425

  3. Flow-injection determination of copper(II) based on its catalysis on the redox reaction of cysteine with iron(III) in the presence of 1,10-phenanthroline

    Microsoft Academic Search

    Norio Teshima; Hideyuki Katsumata; Makoto Kurihara; Tadao Sakai; Takuji Kawashima

    1999-01-01

    A redox reaction of cysteine with iron(III) proceeds slowly in the presence of 1,10-phenanthroline (phen). However, this reaction is accelerated in the presence of copper(II) as a catalyst, producing an iron(II)–phen complex (?max=510 nm). A sensitive spectrophotometric flow-injection method is proposed for the determination of copper(II) based on its catalytic action on this redox reaction. The dynamic range was 0.1–10

  4. Bioaccumulation of lead, copper, iron, and zinc by fish in a transect of the Santa Catarina River in Cadereyta Jimenez, Nuevo Leon, Mexico

    SciTech Connect

    Not Available

    1986-09-01

    Changes have been observed in the ichthyic species community, upriver in the San Juan River in Nuevo Leon, Mexico. A disappearance of Notropis amabilis, Notropis stramineus, Dionda episcopa and Campostoma anomalum and an increased mortality of Astyanax mexicanus, Lepomis macrochirus and Cichlasoma cyanoguttatum have been found. These changes were probably due to industrial and domestic discharges which produced high levels of lead, copper, iron and detergents in the water. The investigation reported here was done in order to detect the possible presence of lead, copper, iron and zinc in the river waters and also, to determine a probable bioaccumulation of these metals in fish species of the Santa Catarina River in the state of Nuevo Leon in northeastern Mexico, since this river transports domestic and industrial wastes of urban and suburban zones.

  5. Effect of lactose, copper and iron on manganese retention and tissue distribution in rats fed dextrose-casein diets.

    PubMed

    King, B D; Lassiter, J W; Neathery, M W; Miller, W J; Gentry, R P

    1980-03-01

    The effect of iron, lactose and copper on manganese retention was studied in rats fed two diets. Thirty-six male albino rats (75 to 100 g) were allotted to six groups of six rats each. Three groups received a purified manganese-free dextrose-casein diet, and three groups received the same purified diet with 17% lactose added at the expense of dextrose. One group fed each of the above diets received either a manganese-free mineral mixture, the mineral mixture with 5 ppm supplemental Cu or the same mineral mixture with Fe removed. After 7 days on the diets, each rat was given, by gavage, 10 muCi of 54Mn activity as 54MnCl2 in a sodium acetate buffer. On the third day after dosing, the rats were sacrificed and samples of liver, kidneys, semitendinosus muscle, spleen and tibia were taken for stable and radioactive manganese analysis. Lactose added to the purified diet depressed 54Mn retention in all tissues studied. Lactose addition also decreased specific activities of the livers and kidneys but tended to increase stable manganese values. Copper apparently had little direct effect on 54Mn retention but tended to reduce the effect of lactose on 54Mn retention. Omission of Fe greatly increased 54Mn retention values in all tissues studied with or without added lactose. Fe omission also significantly increased the specific activities and stable Mn values of livers and the specific activity of kidneys. The results indicate that low dietary Fe may be a contributing factor to the increased manganese retention observed in this study and a previous study. PMID:7364681

  6. Comparative study of alloxan effects in copper-loaded and iron-loaded rats: lipid peroxidation, protein oxidation, proteasome and antioxidant enzyme activities

    Microsoft Academic Search

    Albena Alexandrova; Almira Georgieva; Lubomir Petrov; Elina Tsvetanova; Margarita Kirkova

    2006-01-01

    The in-vivo effects of alloxan on protein oxidation and lipid peroxidation, as well as on proteasome and antioxidant enzyme activities\\u000a in liver and kidney of copper-loaded and iron-loaded rats, were studied. In control animals, a single alloxan dose (120 mg\\/kg,\\u000a i.p.) increased blood-glucose concentration at the 24th hr and 48th hr and, especially, on the 5th day. For these periods

  7. Neutron activation cross sections for copper, europium, hafnium, iron, nickel, silver, terbium and titanium from the Argonne, Los Alamos and Jaeri collaboration

    Microsoft Academic Search

    J. W. Meadows; D. L. Smith; L. R. Greenwood; R. C. Haight; Y. Ideda; C. Konno

    1995-01-01

    Several fast-neutron activation reactions for copper, europium, hafnium, iron, nickel, silver, terbium and titanium that are important to fusion energy have been investigated in three distinct neutron fields generated by accelerators at Argonne National Laboratory and Los Alamos National Laboratory, USA, and Japan Atomic Energy Research Institute, Tokai, Japan. Final differential cross-sections at 14.7 MeV and integral cross sections for

  8. Identification of Negative cis-Acting Elements in Response to Copper in the Chloroplastic Iron Superoxide Dismutase Gene of the Moss Barbula unguiculata

    Microsoft Academic Search

    Miwa Nagae; Masaru Nakata; Yohsuke Takahashi

    2008-01-01

    Superoxide dismutases (SODs) are ubiquitous metalloenzymes that catalyze the dismutation of superoxide radicals. Chloroplasts have two isozymes, copper\\/zinc SOD (Cu\\/ZnSOD) and iron SOD (FeSOD), encoded by nuclear genes. Because bryophytes are considered as the earliest land plants, they are one of the most interesting plant models for adaptation against oxidative stress. In a previous study, we found that the FeSOD

  9. Influence of Copper, Iron, Zinc and Fe 3 + Haemoglobin Levels on the Etiopathogenesis of Chronic Calcific Pancreatitis—A Study in Patients with Pancreatitis

    Microsoft Academic Search

    Geetha Arumugam; Monika Padmanaban; Dhanya Krishnan; Saranya Panneerselvam; Surendran Rajagopal

    2011-01-01

    Chronic pancreatitis is a serious condition associated with severe abdominal pain, and a significant percentage of patients\\u000a progresses to irreversible calcification in pancreas. The present study evaluates the degree to which the levels of trace\\u000a elements, copper, iron, selenium, zinc and haemoglobin-Fe3+, in blood, serum and pancreas have any role to play in the calcification process associated with fibrosis in

  10. Effects of Dietary Nickel and Protein on Growth, Nitrogen Metabolism and Tissue Concentrations of Nickel, Iron, Zinc, Manganese and Copper in Calves1

    Microsoft Academic Search

    JERRY W. SPEARS; R. W. HARVEY

    Thirty male calves were used in a 2 x 3 factorial arrangement of treatments to determine the effects of dietary nickel and protein on performance, urease activity and tissue concentrations of nickel, iron, zinc, copper and manganese Protein levels evaluated were 10.0, 12.25 and 14.5%, and nickel was supplemented at a level of 0 or 5 mg\\/kg of diet. Nickel

  11. Coumarin-based fluorescent probes for dual recognition of copper(II) and iron(III) ions and their application in bio-imaging.

    PubMed

    García-Beltrán, Olimpo; Cassels, Bruce K; Pérez, Claudio; Mena, Natalia; Núñez, Marco T; Martínez, Natalia P; Pavez, Paulina; Aliaga, Margarita E

    2014-01-01

    Two new coumarin-based "turn-off" fluorescent probes, (E)-3-((3,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS1) and (E)-3-((2,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS2), were synthesized and their detection of copper(II) and iron(III) ions was studied. Results show that both compounds are highly selective for Cu²? and Fe³? ions over other metal ions. However, BS2 is detected directly, while detection of BS1 involves a hydrolysis reaction to regenerate 3-amino-7-hydroxycoumarin (3) and 3,4-dihydroxybenzaldehyde, of which 3 is able to react with copper(II) or iron(III) ions. The interaction between the tested compounds and copper or iron ions is associated with a large fluorescence decrease, showing detection limits of ca. 10?? M. Preliminary studies employing epifluorescence microscopy demonstrate that Cu²? and Fe³? ions can be imaged in human neuroblastoma SH-SY5Y cells treated with the tested probes. PMID:24419164

  12. Coumarin-Based Fluorescent Probes for Dual Recognition of Copper(II) and Iron(III) Ions and Their Application in Bio-Imaging

    PubMed Central

    García-Beltrán, Olimpo; Cassels, Bruce K.; Pérez, Claudio; Mena, Natalia; Núñez, Marco T.; Martínez, Natalia P.; Pavez, Paulina; Aliaga, Margarita E.

    2014-01-01

    Two new coumarin-based “turn-off” fluorescent probes, (E)-3-((3,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS1) and (E)-3-((2,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS2), were synthesized and their detection of copper(II) and iron(III) ions was studied. Results show that both compounds are highly selective for Cu2+ and Fe3+ ions over other metal ions. However, BS2 is detected directly, while detection of BS1 involves a hydrolysis reaction to regenerate 3-amino-7-hydroxycoumarin (3) and 3,4-dihydroxybenzaldehyde, of which 3 is able to react with copper(II) or iron(III) ions. The interaction between the tested compounds and copper or iron ions is associated with a large fluorescence decrease, showing detection limits of ca. 10?5 M. Preliminary studies employing epifluorescence microscopy demonstrate that Cu2+ and Fe3+ ions can be imaged in human neuroblastoma SH-SY5Y cells treated with the tested probes. PMID:24419164

  13. Iron

    MedlinePLUS

    ... disease and restless leg syndrome. Taking iron with levothyroxine can reduce this medication’s effectiveness. Levothyroxine (Levothroid®, Levoxyl®, Synthroid®, Tirosint®, and Unithroid®) is used ...

  14. Synthesis and properties of ternary GIC with iron or copper chlorides

    Microsoft Academic Search

    O. N. Shornikova; A. V. Dunaev; N. V. Maksimova; V. V. Avdeev

    2006-01-01

    The variety of graphite intercalation compounds (GIC) is provided by the possibility to obtain ternary intercalation (TGIC) compounds containing two or more intercalates. A wide range of metal chlorides (FeCl3, AlCl3, CuCl2, NiCl2) and Brönsted acids (HNO3, CH3COOH, H2SO4) are generally used as intercalates. Iron chloride intercalation into the graphite leads to the formation of binary GIC with composition C6nFeCl3.

  15. Barium bright and heavy

    NASA Astrophysics Data System (ADS)

    Fromm, Katharina M.

    2013-02-01

    Katharina M. Fromm relates how barium and its ores went from a magical, glowing species that attracted witches and alchemists to components in a variety of compounds that are key parts of modern life.

  16. Redox-activity and self-organization of iron-porphyrin monolayers at a copper/electrolyte interface.

    PubMed

    Phan, Thanh Hai; Wandelt, Klaus

    2015-03-14

    The electrochemical behaviour and molecular structure of a layer of water-soluble 5,10,15,20-Tetrakis-(N-methyl-4-pyridyl)-porphyrin-Fe(III) pentatosylate, abbreviated as FeTMPyP, on a chloride modified Cu(100) electrode surface were investigated by means of cyclic voltammetry (CV) and in-situ electrochemical scanning tunneling microscopy. Voltammetric results of HOPG in an electrolyte containing FeTMPyP molecules indicate three distinguishable redox steps involving both the central iron metal and the ?-conjugated ring system. However, only the first two reduction steps are observable within the narrow potential window of CVs of Cu(100) measured in the same electrolyte. In the potential range below the first reduction peak, at which the [Fe(III)TMPyP](5+) molecules are reduced to the corresponding [Fe(II)TMPyP](4+) species, in-situ scanning tunneling microscopy (STM) images revealed, for the first time, a highly ordered adlayer of this reduced porphyrin species on the chloride terminated Cu(100) surface. The ordered adlayer exhibits a (quasi)square unit cell with the lattice vectors |a?2|=|b?2|=1.53±0.1 nm and an angle of 93° ± 2° between them. A model is proposed based on the STM observation illustrating the arrangement of the [Fe(II)TMPyP](4+) molecules at the electrolyte/copper interface. PMID:25770506

  17. Effect of dietary phytic acid and cadmium on the availability of cadmium, zinc, copper, iron, and manganese to rats

    SciTech Connect

    Turecki, T.; Ewan, R.C.; Stahr, H.M. [Iowa State Univ., Ames, IA (United States)

    1995-05-01

    The main route of cadmium intake for general population, both human and animal, is via ingestion. The intestinal absorption of cadmium is relatively low, 6% of a single oral dose for humans and less than 2% for various animal species. However, due to poor excretion, accumulation of cadmium occurs, primarily in kidney. The chronic exposure even to low levels of dietary cadmium can lead to the development of renal disturbances. Fox (1988) suggests that phytic acid might be a dietary component capable to influence the intestinal absorption of cadmium. Phytic acid naturally occurs as the major phosphorus storage constituent of most cereals, legumes, and oilseeds. At physiological pH, phytic acid is ionized and has a strong affinity for divalent cations. The potential of phytic acid to decrease the availability of Zn has been for long time of concern for nutritionists. Phytic acid has also been reported to decrease the availability of other trace metals. For nonessential elements, reduced availability of lead has been observed. The experimental data concerning the effect of dietary phytic acid on the availability of dietary cadmium are limited to the work of Rose and Quarterman (1984). The objective of this experiment was to examine: (1) the effect of dietary phytic acid on the availability of cadmium under conditions of chronic dietary exposure of rats to cadmium, and (2) the effect of dietary phytic acid and of chronic dietary exposure to cadmium on the availability of zinc, copper, iron, and manganese to rats. 19 refs., 4 tabs.

  18. Fabrication of superhydrophobic surfaces with hierarchical structure through a solution-immersion process on copper and galvanized iron substrates.

    PubMed

    Xu, Wenguo; Liu, Hongqin; Lu, Shixiang; Xi, Jinming; Wang, Yanbin

    2008-10-01

    Superhydrophobic surfaces were obtained on copper and galvanized iron substrates by means of a simple solution-immersion process: immersing the clean metal substrates into a methanol solution of hydrolyzed 1H,1H,2H,2H-perfluorooctyltrichlorosilane (CF3(CF2)5(CH2) 2SiCl3, FOTMS) for 3-4 days at room temperature and then heated at 130 degrees C in air for 1 h. Both of the resulting surfaces have a high water contact angle (CA) of larger than 150.0 degrees as well as a small sliding angle (SA) of less than 5 degrees . The formation and structure of the superhydrophobic surfaces were characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectrometry (EDX). SEM images showed that both of the resulting surfaces exhibited special hierarchical structure. The special hierarchical structure along with the low surface energy leads to the high surface superhydrophobicity. PMID:18774835

  19. Copper stable isotopes as tracers of metal-sulphide segregation and fractional crystallisation processes on iron meteorite parent bodies

    NASA Astrophysics Data System (ADS)

    Williams, Helen M.; Archer, Corey

    2011-06-01

    We report high precision Cu isotope data coupled with Cu concentration measurements for metal, troilite and silicate fractions separated from magmatic and non-magmatic iron meteorites, analysed for Fe isotopes (? 57Fe; permil deviation in 57Fe/ 54Fe relative to the pure iron standard IRMM-014) in an earlier study ( Williams et al., 2006). The Cu isotope compositions (? 65Cu; permil deviation in 65Cu/ 63Cu relative to the pure copper standard NIST 976) of both metals (? 65Cu M) and sulphides (? 65Cu FeS) span much wider ranges (-9.30 to 0.99‰ and -8.90 to 0.63‰, respectively) than reported previously. Metal-troilite fractionation factors (? 65Cu M-FeS = ? 65Cu M - ? 65Cu FeS) are variable, ranging from -0.07 to 5.28‰, and cannot be explained by equilibrium stable isotope fractionation coupled with either mixing or reservoir effects, i.e. differences in the relative proportions of metal and sulphide in the meteorites. Strong negative correlations exist between troilite Cu and Fe (? 57Fe FeS) isotope compositions and between metal-troilite Cu and Fe (? 57Fe M-FeS) isotope fractionation factors, for both magmatic and non-magmatic irons, which suggests that similar processes control isotopic variations in both systems. Clear linear arrays between ? 65Cu FeS and ? 57Fe FeS and calculated Cu metal-sulphide partition coefficients (D Cu = [Cu] metal/[Cu] FeS) are also present. A strong negative correlation exists between ? 57Fe M-FeS and D Cu; a more diffuse positive array is defined by ? 65Cu M-FeS and D Cu. The value of D Cu can be used to approximate the degree of Cu concentration equilibrium as experimental studies constrain the range of D Cu between Fe metal and FeS at equilibrium to be in the range of 0.05-0.2; D Cu values for the magmatic and non-magmatic irons studied here range from 0.34 to 1.11 and from 0.04 to 0.87, respectively. The irons with low D Cu values (closer to Cu concentration equilibrium) display the largest ? 57Fe M-FeS and the lowest ? 65Cu M-FeS values, whereas the converse is observed in the irons with large values D Cu that deviate most from Cu concentration equilibrium. The magnitudes of Cu and Fe isotope fractionation between metal and FeS in the most equilibrated samples are similar: 0.25 and 0.32‰/amu, respectively. As proposed in an earlier study ( Williams et al., 2006) the range in ? 57Fe M-FeS values can be explained by incomplete Fe isotope equilibrium between metal and sulphide during cooling, where the most rapidly-cooled samples are furthest from isotopic equilibrium and display the smallest ? 57Fe M-FeS and largest D Cu values. The range in ? 65Cu M-FeS, however, reflects the combined effects of partial isotopic equilibrium overprinting an initial kinetic signature produced by the diffusion of Cu from metal into exsolving sulphides and the faster diffusion of the lighter isotope. In this scenario, newly-exsolved sulphides initially have low Cu contents (i.e. high D Cu) and extremely light ? 65Cu FeS values; with progressive equilibrium and fractional crystallisation the Cu contents of the sulphides increase as their isotopic composition becomes less extreme and closer to the metal value. The correlation between ? 65Cu M-FeS and ? 57Fe M-FeS is therefore a product of the superimposed effects of kinetic fractionation of Cu and incomplete equilibrium between metal and sulphide for both isotope systems during cooling. The correlations between ? 65Cu M-FeS and ? 57Fe M-FeS are defined by both magmatic and non-magmatic irons record fractional crystallisation and cooling of metallic melts on their respective parent bodies as sulphur and chalcophile elements become excluded from crystallised solid iron and concentrated in the residual melt. Fractional crystallisation processes at shallow levels have been implicated in the two main classes of models for the origin of the non-magmatic iron meteorites; at (i) shallow levels in impact melt models and (ii) at much deeper levels in models where the non-magmatic irons represent metallic melts that crystallised within the in

  20. Manganese(II), iron(II), cobalt(II), and copper(II) complexes of an extended inherently chiral tris-bipyridyl cage

    PubMed Central

    Perkins, David F.; Lindoy, Leonard F.; McAuley, Alexander; Meehan, George V.; Turner, Peter

    2006-01-01

    Manganese(II), iron(II), cobalt(II), and copper(II) derivatives of two inherently chiral, Tris(bipyridyl) cages (L and L?) of type [ML]-(PF6)2(solvent)n and [FeL?](ClO4)2 are reported, where L is the hexa-tertiary butyl-substituted derivative of L?. These products were obtained by using the free cage and metal template procedures; the latter involved the reductive amination of the respective Tris-dialdehyde precursor complexes of iron(II), cobalt(II), or nickel(II). Electrochemical, EPR, and NMR studies have been used to probe the nature of the individual complexes. X-ray structures of the manganese(II), iron(II), and copper(II) complexes of L and the iron(II) complex of L? are presented; these are compared with the previously reported structures of the corresponding nickel(II) complex and metal-free cage (L). In each complex the metal cation occupies the cage's central cavity and is coordinated to six nitrogens from the three bipyridyl groups. The cations [MnL]2+ and [FeL]2+ are isostructural but both exhibit a different arrangement of the bound cage to that observed in the corresponding nickel(II) and copper(II) complexes. The latter have an exo-exo arrangement of the bridgehead nitrogen lone pairs, with the metal inducing a triple helical twist that extends ?22 Å along the axial length of each complex. In contrast, [MnL]2+ and [FeL]2+ have their terminal nitrogen lone pairs directed endo, causing a significant change in the configuration of the bound ligand. In [FeL?]2+, the cage has both bridgehead nitrogen lone pairs orientated exo. Semiempirical calculations indicate that the observed endo-endo and exo-exo arrangements are of comparable energy. PMID:16407129

  1. Inductively coupled plasma atomic fluorescence spectrometric determination of cadmium, copper, iron, lead, manganese and zinc

    USGS Publications Warehouse

    Sanzolone, R.F.

    1986-01-01

    An inductively coupled plasma atomic fluorescence spectrometric method is described for the determination of six elements in a variety of geological materials. Sixteen reference materials are analysed by this technique to demonstrate its use in geochemical exploration. Samples are decomposed with nitric, hydrofluoric and hydrochloric acids, and the residue dissolved in hydrochloric acid and diluted to volume. The elements are determined in two groups based on compatibility of instrument operating conditions and consideration of crustal abundance levels. Cadmium, Cu, Pb and Zn are determined as a group in the 50-ml sample solution under one set of instrument conditions with the use of scatter correction. Limitations of the scatter correction technique used with the fluorescence instrument are discussed. Iron and Mn are determined together using another set of instrumental conditions on a 1-50 dilution of the sample solution without the use of scatter correction. The ranges of concentration (??g g-1) of these elements in the sample that can be determined are: Cd, 0.3-500; Cu, 0.4-500; Fe, 85-250 000; Mn, 45-100 000; Pb, 5-10 000; and Zn, 0.4-300. The precision of the method is usually less than 5% relative standard deviation (RSD) over a wide concentration range and acceptable accuracy is shown by the agreement between values obtained and those recommended for the reference materials.

  2. Acute and subacute response of iron, zinc, copper and selenium in pigs experimentally infected with Actinobacillus pleuropneumoniae.

    PubMed

    Humann-Ziehank, Esther; Menzel, Anne; Roehrig, Petra; Schwert, Barbara; Ganter, Martin; Hennig-Pauka, Isabel

    2014-10-01

    This study was performed to characterise the response of iron (Fe), zinc (Zn), copper (Cu) and selenium (Se) in bacterial-induced porcine acute phase reaction (APR). Twenty piglets were challenged by aerosolic infection with Actinobacillus pleuropneumoniae (A.pp.) serotype 2, ten piglets serving as controls. Blood sampling was done initially and at day 4 and 21 after infection, collection of liver tissue was done at day 21 (autopsy). A.pp.-infection caused fever and respiratory symptoms. APR at day 4 after infection was marked by an increase in total white blood cells, granulocytes and monocytes in whole blood samples and an increase in globulin/albumin ratio (G/A), ?2-globulins, C-reactive protein, haptoglobin, ceruloplasmin (Cp), Cu and Se in serum. Concurrently, there was a decrease in haemoglobin (Hb) and packed cell volume (PCV) in whole blood as well as a decrease in albumin, transferrin, total iron binding capacity and Fe in serum and Zn in plasma. The subacute stage at day 21 was characterised by progressively increased concentrations of G/A, ?-globulins and ?-globulins reflecting the specific immune reaction. Hb and PCV showed further decreases, all other parameters returned to the initial concentrations. Glutathione peroxidase activity in plasma and liver tissue remained unaffected by A.pp.-infection. The liver concentration (day 21) of Zn was found to be higher, that of Se was lower in the A.pp.-group, whereas hepatic concentrations of Cu and Fe were not affected by A.pp.-infection. In summary, the acute and subacute stages of A.pp.-infection were accurately characterised by the APR-related parameters. Se was only marginally affected by the A.pp.-infection. The elevated plasma Cu concentration may be a side effect of the transient hepatic induction of Cp synthesis. Zn responded, being distinctly reduced in plasma and probably having been sequestered in the liver tissue. Reduction in serum Fe can be regarded as an unspecific defence mechanism in A.pp.-infection to withdraw Fe from bacterial acquisition systems. PMID:25100437

  3. Iron(II) and copper(I) coordination polymers: electrochromic materials with and without chiroptical properties.

    PubMed

    Bernhard, Stefan; Goldsmith, Jonas I; Takada, Kazutake; Abruña, Héctor D

    2003-07-14

    The electrochemical and optical properties of films prepared from two different Fe(II) coordination polymers (TPT[Fe(II)TPT](n)(PF(6))(2)(n) (TPT = terpyridine-phenyl-terpyridine) and CTPCT[Fe(II)CTPCT](n)(PF(6))(2)(n) (CTPCT = chiral terpyridine-phenyl-chiral terpyridine)) and a coordination polymer based on Cu(I) metal centers (PDP[Cu(I)PDP](n)(BF(4))(n)) (PDP = phenanthroline-dodecane-phenanthroline) have been studied. The oxidation of a PDP[Cu(I)PDP](n)(BF(4))(n) film coated on an indium-tin oxide (ITO) electrode by stepping the potential from 0.0 to +1.4 V vs Ag/AgCl led not only to the complete bleaching of the absorption in the visible region of the spectrum within 5 min but also to a redox-induced dissociation and dissolution of the polymer. The reverse reaction of binding and reassembling the polymer at the electrode surface, upon stepping the potential back to 0.0 V, occurred with a rate which was at least 1 order of a magnitude slower. In contrast, the bis(2,2':6',2' '-terpyridine)iron(II)-based redox polymers TPT[Fe(II)TPT](n)(PF(6))(2)(n) and CTPCT[Fe(II)CTPCT](n)(PF(6))(2)(n), during similar spectroelectrochemical experiments, not only exhibited a dramatically enhanced switching rate but also displayed symmetric switching kinetics. The films did not show signs of deterioration over 150 switching cycles. Additionally, in an effort to assemble an electrochromic device with chiroptical properties, the electrochromism of films generated from the enantiomerically pure CTPCT[Fe(II)CTPCT](n)(PF(6))(2)(n) polymer was studied through circular dichroism. PMID:12844311

  4. Selenium, copper, zinc, iron and manganese content of seven meat cuts from Hereford and Braford steers fed pasture in Uruguay.

    PubMed

    Cabrera, M C; Ramos, A; Saadoun, A; Brito, G

    2010-03-01

    Tenderloin (T), eye of rump (E), striploin (S), eye round (ER), tri-tip (TT), rib-eye roll (RR) and three rib plate-flank on (RP) meat cuts were evaluated. Selenium contents ranged between 0.42 and 1.20 mg/kg wet tissue (wt) in Hereford (H) breed and between 0.49 and 1.3 mg/kg wt in Braford (B) breed. In H and B breeds, T, TT and RP, and TT and RP were the richest cuts in selenium, respectively. Copper contents ranged between 0.25 and 1.04 mg/kg wt in H, and between 0.19 and 1.09 mg/kg wt in B. In H breed, RP had significantly more Cu than ER, TT, and RR. In B breed, ER and RR show a significant lower Cu level in comparison to the other meat cuts. Zinc contents ranged between 23 and 72.7 mg/kg wt in H, and between 23 and 63.9 mg/kg wt in B. RP is the richest cut in Zn compared to the other cuts in the two breeds. Iron contents ranged between 16.4 and 48.2 mg/kg wt in H, and between 14.2 and 47.9 mg/kg wt in B. In H breed, RR shows a lower content compared to the other cuts, except RP and S. In B breed, RR had the lowest level of Fe compared to the other cuts, except RP and T. Manganese contents ranged between 0.05 and 0.17 mg/kg wt in H, and between 0.04 and 0.48 mg/kg wt in B. In H no differences were detected between cuts. In B breed, ER cut shows the highest level of Mn. PMID:20374819

  5. Copper and Copper Proteins in Parkinson's Disease

    PubMed Central

    Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology. PMID:24672633

  6. Plasma deposition of thin layers containing titanium and barium with the use of DBD

    NASA Astrophysics Data System (ADS)

    Majdak, Ma?gorzata; Opali?ska, Teresa; Wn?k, Bart?omiej; Konarski, Piotr

    2013-02-01

    Two different methods of deposition of thin layers containing titanium and barium with the use of dielectric barrier discharge were investigated. The first was carried out in two stages. The first stage consisted in transferring compounds containing titanium and barium from the vapor of the organic precursor to the copper substrate, while the second stage involved the etching of the organic layer in oxygen. The second method consisted in transferring titanium and barium to the copper substrate from the ceramic plate made of barium titanate, which was one of the electrodes during the plasma process. The results of analysis obtained by SIMS showed directly that both methods gave a positive result in the deposition of the thin layers containing a certain amount of titanium and barium on the surface of the copper plate. However, more effective method was that involving the properties of reaction with the metallorganic precursor. FTIR study of the layers prepared from the organic precursor indirectly showed that layers deposited on the copper plate contained compounds of barium and titanium. FTIR study also revealed that during the process of etching in oxygen, the organic layer was decreased, but it was not completely removed. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.

  7. Kinetics and mechanism of the oxidation of (. cap alpha. -hydroxyalkyl)chromium complexes by copper(II) and iron(III) ions

    SciTech Connect

    Bakac, A.; Espenson, J.H.

    1981-05-20

    Copper(II) and iron(III) ions react with (..cap alpha..-hydroxyalkyl)chromium(2+) complexes (alkyl = methyl, ethyl, 2-propyl) in water or in aqueous alcohol solutions leading to the cleavage of the chromium-carbon bond. The immediate products are Cr/sup 2 +/, the reduced metal ion (Cu/sup +/ or Fe/sup 2 +/), and the corresponding aldehyde or ketone. The reactions obey the rate law -d(CrROH/sup 2 +/)/dt = (k + k'(H)/sup -1/(CrROH/sup 2 +/)(M), where M = Cu/sup 2 +/ or Fe/sup 3 +/. The dominant k' term has the following values in 1 M aqueous parent alcohol (methanol, ethanol, and 2-propanol, respectively): CrCH/sub 2/OH/sup 2 +/, k'/sub Cu/ = 0.251 s/sup -1/,k'/sub Fe/ = 0.496 s/sup -1/; CrCH(CH/sub 3/)OH/sup 2 +/, 1.46, 0.481; CrC(CH/sub 3/)/sub 2/OH/sup 2 +/, 0.574, 1.90. The reactivity toward Cu/sup 2 +/ and Fe/sup 3 +/ is significantly diminished upon substitution of the OH hydrogen by an alkyl group. Copper(II) does not react with (..cap alpha..-alkoxyalkyl)chromium(2+) complexes at all, while iron(III) shows some reactivity with k'/sub Fe/ = 0.0127 s/sup -1/ (CrCH/sub 2/OCH/sub 3//sup 2 +/) and 0.0400 s/sup -1/ (CrCH(CH/sub 3/)OC/sub 2/H/sub 5//sup 2 +/), both in 1 M methanol. A mechanism proposed for the oxidation of (..cap alpha..-hydroxyalkyl)chromium(2+) complexes by copper(II) and iron(III) consists of the oxidant attack at the alcoholic OH group followed by a slow electron-transfer step.

  8. Rare earths and other trace elements in minerals from skarn assemblages, Hillside iron oxide-copper-gold deposit, Yorke Peninsula, South Australia

    NASA Astrophysics Data System (ADS)

    Ismail, Roniza; Ciobanu, Cristiana L.; Cook, Nigel J.; Teale, Graham S.; Giles, David; Mumm, Andreas Schmidt; Wade, Benjamin

    2014-01-01

    The Hillside Cu-(Au) deposit, Yorke Peninsula, South Australia, is a recently-discovered ore system within the 1.6 Ga World-class Olympic iron oxide-copper-gold (IOCG) Province. The deposit is characterized by a skarn-style alteration zone. Analyses of feldspar, calcite, skarn minerals (garnet, pyroxene, clinozoisite and actinolite) and accessories (titanite, apatite and allanite), and grain-scale element mapping by laser-ablation inductively-coupled plasma mass spectrometry are used to assess the distributions of rare earth element (REE), incompatible and ore-forming elements in host rocks, prograde and retrograde skarn.

  9. Chelatometric determination of calcium and magnesium in iron ores, slags, anorthosite, limestone, copper-nickel-lead-zinc ores and divers materials.

    PubMed

    Hitchen, A; Zechanowitsch, G

    1980-03-01

    Chelatometric methods for the determination of calcium and magnesium in iron ores, slags, anorthosite, copper-nickel-lead-zinc ores and various other materials are described. Potential interfering elements are masked with triethanolamine and potassium cyanide. In one aliquot calcium is titrated at pH > 12, with calcein and thymolphthalein mixed indicator and in another aliquot calcium and magnesium are titrated in ammonia buffer, with o-cresolphthalein complexone screened with Naphthol Green B as indicator. The results compare favourably with certified values for reference materials of diverse nature. PMID:18962661

  10. Spatial and temporal zoning of hydrothermal alteration and mineralization in the Sossego iron oxide–copper–gold deposit, Carajás Mineral Province, Brazil: paragenesis and stable isotope constraints

    Microsoft Academic Search

    Lena V. S. Monteiro; Roberto P. Xavier; Emerson R. de Carvalho; Murray W. Hitzman; Craig A. Johnson; Carlos Roberto de Souza Filho; Ignácio Torresi

    2008-01-01

    The Sossego iron oxide–copper–gold deposit (245 Mt @ 1.1% Cu, 0.28 g\\/t Au) in the Carajás Mineral Province of Brazil consists\\u000a of two major groups of orebodies (Pista–Sequeirinho–Baiano and Sossego–Curral) with distinct alteration assemblages that are\\u000a separated from each other by a major high angle fault. The deposit is located along a regional WNW–ESE-striking shear zone\\u000a that defines the contact between

  11. Semiconducting barium titanate

    Microsoft Academic Search

    W. Heywang

    1971-01-01

    Barium titanate, which is well known as a basic ferroelectric material, is also of interest when doped because of the interaction between semiconductivity and ferroelectricity. The resistance of blocking layers at surfaces and grain-boundaries is governed mainly by the ferroelectric properties, so that a resistance jump of four decades is observed on heating above the Curie temperature. A survey of

  12. Reducing effect of ingesting tannic acid on the absorption of iron, but not of zinc, copper and manganese by rats.

    PubMed

    Afsana, Kaosar; Shiga, Kazuki; Ishizuka, Satoshi; Hara, Hiroshi

    2004-03-01

    Interest in the beneficial effects of polyphenols, including tannic acid (TA), is increasing, although, these compounds also have adverse effects; for example, on the absorption of iron (Fe), and possibly other trace minerals. We examined the effect of a graded dose of TA on the absorption of Fe and compared with that of zinc (Zn), copper (Cu) and manganese (Mn) in rats. We also investigated the effect of TA on cecal fermentation which plays a role in absorption. In Experiment 1, to set the optimum dose of Fe, male Sprague-Dawley rats (weighing 70-90 g) after acclimatization were fed with different levels of dietary Fe (5, 10, 20, 30 and 35 mg/kg). We observed that the hematocrit (Ht), serum Fe concentration and transferrin saturation (%) were each reduced in those rats fed less than 20 mg/kg Fe in a dose-dependent manner. In Experiment 2, the rats were fed with test diets containing the minimum required level of Fe, 30 mg/kg diet, with (5, 10, 15 and 20 g/kg diet) or without TA for a period of three weeks. Feeding a diet containing more than 10 g TA/kg diet, but not 5 g TA/kg diet, reduced the hemoglobin concentration (Hb), Ht and serum Fe concentration due to decreased Fe absorption. In contrast, the Zn, Cu and Mn absorption was not affected by TA feeding. It is also demonstrated that liver Fe, but not the Zn, Cu and Mn contents, were lower in the TA groups than in the TA-free control group. Feeding TA slightly decreased the pH value of the cecal contents with an increase in the major short-chain fatty acid pool. About 15% of the ingested TA were recovered in the feces of each TA-fed group. Our results demonstrate that more than 10 g TA/kg diet induced anemia by reducing the Fe absorption, although there was no effect on the absorption of other important trace minerals. Our findings suggest that the usual intake of polyphenols is relatively safe, but that a high intake by supplementation or by dietary habit of tannin affects only the Fe level. PMID:15056891

  13. Syntheses and structural characterization of iron(II) and copper(II) coordination compounds with the neutral flexible bidentate N-donor ligands

    NASA Astrophysics Data System (ADS)

    Beheshti, Azizolla; Lalegani, Arash; Bruno, Giuseppe; Rudbari, Hadi Amiri

    2014-08-01

    Two new coordination compounds [Fe(bib)2(N3)2]n(1) and [Cu2(bpp)2(N3)4] (2) with azide and flexible ligands 1,4-bis(imidazolyl)butane (bib) and 1,3-bis(3,5-dimethylpyrazolyl)propane (bpp) were prepared and structurally characterized. In the 2D network structure of 1, the iron(II) ion lies on an inversion center and exhibits an FeN6 octahedral arrangement while in the dinuclear structure of 2, the copper(II) ion adopts an FeN5 distorted square pyramid geometry. In the complex 1, each ?2-bib acts as bridging ligand connecting two adjacent iron(II) ions while in the complex 2, the bpp ligand is coordinated to copper(II) ion in a cyclic-bidentate fashion forming an eight-membered metallocyclic ring. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction. Thermal analysis of polymer 1 was also studied.

  14. In vitro bioaccessibility of copper, iron, zinc and antioxidant compounds of whole cashew apple juice and cashew apple fibre (Anacardium occidentale L.) following simulated gastro-intestinal digestion.

    PubMed

    de Lima, Ana Cristina Silva; Soares, Denise Josino; da Silva, Larissa Morais Ribeiro; de Figueiredo, Raimundo Wilane; de Sousa, Paulo Henrique Machado; de Abreu Menezes, Eveline

    2014-10-15

    Considering the lack of research studies about nutrients' bioaccessibility in cashew apple, in this study the whole cashew apple juice and the cashew apple fibre were submitted to simulated in vitro gastrointestinal digestion. The samples were analysed before and after digestion and had their copper, iron, zinc, ascorbic acid, total extractable phenols and total antioxidant activity assessed. As a result, for the whole cashew apple juice, the content of copper and iron minerals bioaccessible fraction were 15% and 11.5% and for zinc this level was 3.7%. Regarding the cashew apple fibre, the bioaccessible fraction for these minerals was lower than 5%. The ascorbic acid, total extractable polyphenols and total antioxidant activity bioaccessible fraction for whole cashew apple juice showed bioaccessibility percentages of 26.2%, 39% and 27%, respectively, while for the cashew apple fibre, low bioaccessibles levels were found. The bioacessible percentage of zinc, ascorbic acid and total extractable polyphenols were higher in cashew apple juice than cashew apple fibre. PMID:24837932

  15. Microstructural Evolution and Mechanical Properties of Fusion Welds and Simulated Heat-Affected Zones in an Iron-Copper Based Multi-Component Steel

    NASA Astrophysics Data System (ADS)

    Farren, Jeffrey David

    NUCu-140 is a copper-precipitation strengthened steel that exhibits excellent mechanical properties with a relatively simple chemical composition and processing schedule. As a result, NUCu-140 is a candidate material for use in many naval and structural applications. Before NUCu-140 can be implemented as a replacement for currently utilized materials, a comprehensive welding strategy must be developed under a wide range of welding conditions. This research represents an initial step toward understanding the microstructural and mechanical property evolution that occurs during fusion welding of NUCu-140. The following dissertation is presented as a series of four chapters. Chapter one is a review of the relevant literature on the iron-copper system including the precipitation of copper in steel, the development of the NUCu family of alloys, and the formation of acicular ferrite in steel weldments. Chapter two is a detailed study of the precipitate, microstructural, and mechanical property evolution of NUCu-140 fusion welds. Microhardness testing, tensile testing, local-electrode atom probe (LEAP) tomography, MatCalc kinetic simulations, and Russell-Brown strengthening results for gas-tungsten and gas-metal arc welds are presented. Chapter three is a thorough study of the microstructural and mechanical property evolution that occurs in the four critical regions of the HAZ. Simulated HAZ specimens were produced and evaluated using microhardness, tensile testing, and charpy impact testing. MatCalc simulations and R-B strengthening calculations were also performed in an effort to model the experimentally observed mechanical property trends. Chapter 4 is a brief investigation into the capabilities of MatCalc and the R-B model to determine if the two techniques could be used as predictive tools for a series of binary iron-copper alloys without the aid of experimentally measured precipitate data. The mechanical property results show that local softening occurs in the heat-affected zone (HAZ) as a result of either full or partial dissolution of the copper-rich precipitates responsible for strengthening. Re-precipitation of the copper-rich precipitates was observed during the cooling portion of the weld thermal cycle but the resultant precipitate phase fractions were too low to fully recover the lost strength. The coarse-grained HAZ and fusion zone exhibited an acicular type microstructure which led to improved tensile properties when compared to the other regions of the HAZ. MatCalc simulations displayed excellent agreement with the precipitate parameters measured experimentally using the LEAP. The R-B model was shown to provide reasonable agreement under select conditions, but in general was determined to be overly sensitive to small variations in precipitate parameters. As a result in should be considered a qualitative tool only for precipitate radii less than ˜2 nm. Finally, it was determined that the current generation of MatCalc software was unable to accurately capture the precipitate evolution of various binary iron-copper alloys when experimental data sets were not available for calibration of the model parameters.

  16. Silicosis in barium miners.

    PubMed Central

    Seaton, A; Ruckley, V A; Addison, J; Brown, W R

    1986-01-01

    Four men who mined barytes in Scotland and who developed pneumoconiosis are described. Three developed progressive massive fibrosis, from which two died; and one developed a nodular simple pneumoconiosis after leaving the industry. The radiological and pathological features of the men's lungs were those of silicosis and high proportions of quartz were found in two of them post mortem. The quartz was inhaled from rocks associated with the barytes in the mines. The features of silicosis in barium miners are contrasted with the benign pneumoconiosis, baritosis, that occurs in workers exposed to crushed and ground insoluble barium salts. Diagnostic difficulties arise when silicosis develops in workers mining minerals known to cause a separate and benign pneumoconiosis. These difficulties are compounded when, as not infrequently happens, the silicotic lesions develop or progress after exposure to quartz has ceased. Images PMID:3787542

  17. Properties of Semiconductive Barium Titanates

    Microsoft Academic Search

    Osamu Saburi

    1959-01-01

    The resistivity of barium titanate which is usually of the order of 109˜1012 ohm-cm, may be remarkably reduced with suitable control in valency. The valency-controlled barium titanate, whose resistivity is of the order of 10˜104 ohm-cm at room temperature, shows anomalous positive character in the temperature dependency of the resistivity. For example, the resistivity of barium titanate containing 0.1 mol.

  18. Barium Vanadate Microspheres

    NASA Astrophysics Data System (ADS)

    Yosinski, Shari; Tweeton, Landon; Feller, Steve; Affatigato, Mario

    2009-11-01

    It has been found that many glass powders can form micro- or nanospheres when heated in a flame or by a laser. Much of the research in this area of microspheres has concentrated on making hollow spheres, called microballoons, of silica and borosilicate glasses. Our aim was to create highly porous barium vanadate microspheres for possible future applications in material storage. The surface area of porous spheres would provide a greater amount of bonding surface area for dopants than hollow spheres. Barium vanadate glass with a molar fraction of 0.4 to 0.6 barium oxide was used because this glass is stable and has a low Tg. Size distributions of the spheres were quantified and the extent of sphere formation and porosity was examined using a scanning electron microscope. The size of spheres formed is affected by powder size, dropping method, and flame position. The porosity of the microspheres is affected by flame temperature, time spent in flame, and the material onto which the spheres fall. The greatest porosity was achieved by first heating the glass powder at a low temperature and then immediately sending it through the flames of two MAPP gas torches at approximately 2100^oC onto a metal sheet.

  19. Mineral status of non-anemic Peruvian infants taking an iron and copper syrup with or without zinc from 6 to 18 months of age: a randomized controlled trial

    PubMed Central

    Caulfield, Laura E.; Zavaleta, Nelly; Chen, Ping; Colombo, John; Kannass, Kathleen

    2013-01-01

    Objective To evaluate changes in iron, zinc and copper status of non-anemic Peruvian infants receiving daily supplements with 10 mg iron, 0.5 mg copper with or without 10 mg zinc from 6 to 18 months of age. Methods Overall, 251 infants were randomized to one of two daily supplements. Venous blood draws at 6, 12, and 18 months were taken to characterize hemoglobin, plasma ferritin, zinc and copper concentrations. Urinary excretion of zinc was also measured at each time point. Repeated measures ANOVA was used to evaluate changes over time and by supplement type. Results Both hemoglobin and copper concentrations increased significantly, while plasma ferritin decreased from 6 to 12 months of age (P < 0.05). Mean plasma zinc concentrations in the zinc treatment group were maintained over time, while that in the control group declined; differences by treatment were found at 12 and 18 months (P < 0.05). Urinary zinc concentration was increased in the zinc group at 12 months only. There was evidence that zinc treatment improved hemoglobin at 18 months of age (P = 0.09). Compliance with supplementation was high, with 81% of the intended dose consumed over the 12-month period. Conclusions Daily mineral supplementation over one year appears feasible and acceptable in this population, and a combined supplement can improve iron, zinc and copper status of infants at the same time. PMID:24103510

  20. Highly aluminium doped barium and strontium ferrite nanoparticles prepared by citrate auto-combustion synthesis

    Microsoft Academic Search

    Neil J.. Shirtcliffe; Simon Thompson; Eoin S. O’Keefe; Steve Appleton; Carole C.. Perry

    2007-01-01

    Aluminium doped barium and strontium hexaferrite nanoparticles BaAlxFe(12?x)O19 and SrAlxFe(12?x)O19 were synthesised via a sol–gel route using citric acid to complex the ions followed by an auto-combustion reaction. This method shows promise for the synthesis of complex ferrite powders with small particle size. It was found that around half of the iron could be substituted for aluminium in the barium

  1. Barium uranyl diphosphonates

    SciTech Connect

    Nelson, Anna-Gay D., E-mail: nelsoa@umich.edu [Department of Civil Engineering and Geological Sciences and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Alekseev, Evgeny V. [Institute of Energy and Climate Research (IEK-6), Forschungszentrum Juelich Wilhelm-Johnen-Strasse, Juelich 52428 (Germany); Ewing, Rodney C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Albrecht-Schmitt, Thomas E. [Department of Civil Engineering and Geological Sciences and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2012-08-15

    Three Ba{sup 2+}/UO{sub 2}{sup 2+} methylenediphosphonates have been prepared from mild hydrothermal treatment of uranium trioxide, methylendiphosphonic acid (C1P2) with barium hydroxide octahydrate, barium iodate monohydrate, and small aliquots of HF at 200 Degree-Sign C. These compounds, Ba[UO{sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{center_dot}1.4H{sub 2}O (Ba-1), Ba{sub 3}[(UO{sub 2}){sub 4}(CH{sub 2}(PO{sub 3}){sub 2}){sub 2}F{sub 6}]{center_dot}6H{sub 2}O (Ba-2), and Ba{sub 2}[(UO{sub 2}){sub 2}(CH{sub 2}(PO{sub 3}){sub 2})F{sub 4}]{center_dot}5.75H{sub 2}O (Ba-3) all adopt layered structures based upon linear uranyl groups and disphosphonate molecules. Ba-2 and Ba-3 are similar in that they both have UO{sub 5}F{sub 2} pentagonal bipyramids that are bridged and chelated by the diphosphonate moiety into a two-dimensional zigzag anionic sheet (Ba-2) and a one-dimensional ribbon anionic chain (Ba-3). Ba-1, has a single crystallographically unique uranium metal center where the C1P2 ligand solely bridges to form [UO{sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{sup 2-} sheets. The interlayer space of the structures is occupied by Ba{sup 2+}, which, along with the fluoride ion, mediates the structure formed and maintains overall charge balance. - Graphical abstract: Illustration of the stacking of the layers in Ba{sub 3}[(UO{sub 2}){sub 4}(CH{sub 2}(PO{sub 3}){sub 2}){sub 2})F{sub 6}]{center_dot}6H{sub 2}O viewed along the c-axis. The structure is constructed from UO{sub 7} pentagonal bipyramidal units, U(1)O{sub 7}=gray, U(2)O{sub 7}=yellow, barium=blue, phosphorus=magenta, fluorine=green, oxygen=red, carbon=black, and hydrogen=light peach. Highlights: Black-Right-Pointing-Pointer The polymerization of the UO{sub 2}{sup 2+} sites to form uranyl dimers leads to structural variations in compounds. Black-Right-Pointing-Pointer Barium cations stitch uranyl diphosphonate anionic layers together, and help mediate structure formation. Black-Right-Pointing-Pointer HF acts as both a mineralizing agent and a ligand.

  2. Structure of self-interstitial atom clusters in iron and copper Akiyuki Takahashi1 and Nasr M. Ghoniem2

    E-print Network

    Ghoniem, Nasr M.

    and the width of the stacking faults. An applied external shear can delocalize the core of an SIA cluster narrow stacking fault SF region. The compact nature of the SIA core in copper is attributed to the strong dependence of the self-energy on the cluster size. As the number of atoms in the SIA cluster increases

  3. A thermodynamic explanation for the martensitic transformation of nanometer-sized ?-iron particles embedded in a copper matrix

    Microsoft Academic Search

    W. Qin; Y. W. Du; Y. H. Zhuang; Z. H. Chen

    2002-01-01

    The martensitic transformation of nanometer-sized particles precipitating in a copper matrix is analyzed from a thermodynamic viewpoint. It is shown that there exists a critical austenitic particle size below which the austenitic phase becomes more stable than the martensitic phase and the martensitic transformation cannot take place. Prolonged annealing, extraction of particle from the matrix, and plastic deformation would make

  4. Barium iron arsenide, barium cobalt arsenide, barium nickel arsenide single crystals and superconductivity upon cobalt doping

    SciTech Connect

    Ronning, Filip [Los Alamos National Laboratory; Sefat, A S [ORNL; Mcguire, M M [ORNL; Sales, B [ORNL; Jin, R [ORNL; Mandrus, D [ORNL

    2009-01-01

    The crystal structure and physical properties of BaFe{sub 2}As{sub 2}, BaCo{sub 2}As{sub 2}, and BaNi{sub 2}As{sub 2} single crystals are surveyed. BaFe{sub 2}As{sub 2} gives a magnetic and structural transition at T{sub N} = 132(1) K, BaCo{sub 2}As{sub 2} is a paramagnetic metal, while BaNi{sub 2}As{sub 2} has a structural phase transition at T{sub 0} = 131 K, followed by superconductivity below {Tc} = 0.69 K. The bulk superconductivity in Co-doped BaFe{sub 2}As{sub 2} below {Tc} = 22 K is demonstrated by resistivity, magnetic susceptibility, and specific heat data. In contrast to the cuprates, the Fe-based system appears to tolerate considerable disorder in the transition metal layers. First principles calculations for BaFe{sub 1.84}Co{sub 0.16}As{sub 2} inter-band scattering due to Co is weak.

  5. SOURCES OF COPPER AIR EMISSIONS

    EPA Science Inventory

    The report gives results of a study to update estimates of atmospheric emissions of copper and copper compounds in the U.S. Source categories evaluated included: metallic minerals, primary copper smelters, iron and steel making, combustion, municipal incineration, secondary coppe...

  6. Barium uranyl diphosphonates

    NASA Astrophysics Data System (ADS)

    Nelson, Anna-Gay D.; Alekseev, Evgeny V.; Ewing, Rodney C.; Albrecht-Schmitt, Thomas E.

    2012-08-01

    Three Ba2+/UO22+ methylenediphosphonates have been prepared from mild hydrothermal treatment of uranium trioxide, methylendiphosphonic acid (C1P2) with barium hydroxide octahydrate, barium iodate monohydrate, and small aliquots of HF at 200 °C. These compounds, Ba[UO2[CH2(PO3)2]·1.4H2O (Ba-1), Ba3[(UO2)4(CH2(PO3)2)2F6]·6H2O (Ba-2), and Ba2[(UO2)2(CH2(PO3)2)F4]·5.75H2O (Ba-3) all adopt layered structures based upon linear uranyl groups and disphosphonate molecules. Ba-2 and Ba-3 are similar in that they both have UO5F2 pentagonal bipyramids that are bridged and chelated by the diphosphonate moiety into a two-dimensional zigzag anionic sheet (Ba-2) and a one-dimensional ribbon anionic chain (Ba-3). Ba-1, has a single crystallographically unique uranium metal center where the C1P2 ligand solely bridges to form [UO2[CH2(PO3)2]2- sheets. The interlayer space of the structures is occupied by Ba2+, which, along with the fluoride ion, mediates the structure formed and maintains overall charge balance.

  7. Effects of iron, zinc, calcium, and vitamins on the activity and contents of human placental copper/zinc and manganese superoxide dismutases.

    PubMed

    Hunaiti, A A; Saleh, M S

    1996-09-01

    One hundred seventy-nine pregnant women, ages 15-45 yr, were divided into three groups. Group A was orally given one spansule per day containing 150 mg dried ferrous sulfate, 61.8 mg zinc sulfate, and 500 micrograms folic acid, starting from the first 4 wk of pregnancy and ending at the day of delivery. Similarly, group B was given one tablet containing 625 mg calcium carbonate, 1000 mg vitamin C, 300 IU Vitamin D, 1350 mg citric acid, and 15 mg Vitamin B6. Group C was without any supplements and served as a control. Mothers who received iron/zinc supplements (group A) during pregnancy had significantly higher copper/zinc superoxide dismutase activity in their placentae than calcium/vitamin-supplemented mothers (group B) or unsupplemented mothers (group C). The enzyme activity increased with age of the mothers from 15 to 40 yr, then decreased after in both supplemented groups, whereas this increase and decrease occurred at early age in the unsupplemented group. Immunochemical quantitation of the enzyme contents showed no significant difference between the supplemented and unsupplemented groups, suggesting that the observed increase in the enzyme activity might arise from posttranslational processing of the enzyme. The placental manganese superoxide dismutase activity and contents, however, were similar in the supplemented groups, whereas they were slightly higher in the unsupplemented group; the overall superoxide dismutase-like activities in the placentae were the highest in iron-zinc supplemented group and the lowest in the unsupplemented group. PMID:8909696

  8. 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

    NASA Astrophysics Data System (ADS)

    Sergeant, C.; Vesvres, M. H.; Devès, G.; Guillou, F.

    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.

  9. Formation of nickel and copper ferrites in ceramics: a potential reaction in the reuse of iron-rich sludge incineration ash.

    PubMed

    Shih, Kaimin

    2012-12-01

    This study investigates potential solid-state reactions for the stabilization of hazardous metals when reusing the incineration ash from chemically enhanced primary treatment (CEPT) sludge to fabricate ceramic products. Nickel and copper were used as examples of hazardous metals, and the iron content in the reaction system was found to play a major role in incorporating these hazardous metals into their ferrite phases (NiFe2O4 and CuFe2O4). The results from three-hour sintering experiments on NiO + Fe2O3 and CuO + Fe2O3 systems clearly demonstrate the potential for initiating metal incorporation mechanisms using an iron-containing precursor at attainable ceramic sintering temperatures (above 750 degrees C). Both ferrite phases were examined using a prolonged leaching experiment modified from the widely used toxicity characteristic leaching procedure (TCLP) to evaluate their long-term metal leachability. The leaching results indicate that both the NiFe2O4 and the CuFe2O4 products were significantly superior to their oxide forms in immobilizing hazardous metals. PMID:23437648

  10. Effects of polyphenol-rich plant products from grape or hop as feed supplements on iron, zinc and copper status in piglets.

    PubMed

    Fiesel, Anja; Ehrmann, Melanie; Geßner, Denise K; Most, Erika; Eder, Klaus

    2015-08-01

    Polyphenol-rich plant products as feed supplements have been shown to exert beneficial effects on feed efficiency in piglets. However, tannins as components of polyphenol-rich plant products are able to reduce the absorption of various trace elements. The present study investigated the effect of two polyphenol-rich dietary supplements, grape seed and grape marc meal extract (GME) and spent hops (SH), on iron (Fe), zinc (Zn) and copper (Cu) status in piglets supplied adequately with those trace elements. A trial with three groups of piglets which received a Control diet or the same diet supplemented with either 1% GME or 1% SH over a period of 4 weeks was performed. Concentrations of Fe, Zn and Cu in plasma, total iron binding capacity and saturation of transferrin in plasma did not differ between the three groups. Piglets fed the diet supplemented with SH showed no differences in the concentrations of Fe, Zn and Cu in the liver in comparison to the Control group. Piglets fed the diets supplemented with GME showed slightly lower concentrations of Zn and Cu in the liver than Control piglets (p < 0.05); however, concentrations of both elements remained in the physiological range. Overall, this study shows that the polyphenol-rich plant products GME and SH had marginal effect on the status of Fe, Zn and Cu in piglets. PMID:26097996

  11. The influence of copper surface area on menstrual blood loss and iron status in women fitted with an IUD.

    PubMed

    Milsom, I; Rybo, G; Lindstedt, G

    1990-03-01

    The influence of copper surface area on menstrual blood loss (MBL) was evaluated in 34 healthy women (mean age 36.4 +/- 1.4 yr, range 27-46 yr), who were fitted with a Multiload intrauterine device (IUD) with either 250 mm2 (MLCu-250) or 375 mm2 (MLCu-375) copper wire. MBL prior to IUD insertion was 54.4 +/- 10.3 ml for women subsequently fitted with a MLCu-250 and 56.9 +/- 6.9 ml for women fitted with a MLCu-375. An increase (p less than 0.01) in MBL was recorded 3 months after IUD insertion for both the women fitted with a MLCu-250 (86.4 +/- 10.3 ml) and a MLCu-375 (81.1 +/- 8.3 ml). This increase in MBL remained unchanged throughout the study period of one year. At no point were there any significant differences in MBL or increase in MBL between women fitted with a MLCu-250 or MLCu-375. There were no significant differences in serum ferritin, blood hemoglobin, hematocrit or erythrocyte indices before IUD insertion in the women grouped according to type of IUD, nor were any significant changes recorded in any of these parameters after IUD insertion. Thus, our findings that the increase in copper surface area from 250 mm2 to 375 mm2 had no effect on MBL were also substantiated by the hematological findings. PMID:2323218

  12. Abstract--This paper presents firstly copper and iron losses models of a classical Switched Reluctance Motor (SRM) and a

    E-print Network

    Paris-Sud XI, Université de

    Reluctance Motor (SRM) and a Mutually Coupled Switched Reluctance Motor (MCSRM), the iron losses in different reluctance motor (SRM), finite- element method (FEM). I. INTRODUCTION WITCHED Reluctance Motors (SRMs) have, this kind of motors could be classed into the Mutually Coupled Switched Reluctance Motor (MCSRM) category

  13. Adsorption\\/desorption properties of copper ions on the surface of iron-coated sand using BET and EDAX analyses

    Microsoft Academic Search

    C. H. Lai; S. L. Lo; H. L. Chiang

    2000-01-01

    This study was conducted to develop a heating process for coating hydrated iron oxide on the sand surface to utilise the adsorbent properties of the coating and the filtration properties of the sand. BET and scanning electron microscope (SEM) analyses were used to investigate the surface properties of the coated layer. An energy dispersive X-ray (EDAX) technique of analysis was

  14. Discovery of the Barium Isotopes

    E-print Network

    A. Shore; A. Fritsch; J. Q. Ginepro; M. Heim; A. Schuh; M. Thoennessen

    2009-08-13

    Thirty-eight barium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  15. Barium light source method and apparatus

    NASA Technical Reports Server (NTRS)

    Curry, John J. (Inventor); MacDonagh-Dumler, Jeffrey (Inventor); Anderson, Heidi M. (Inventor); Lawler, James E. (Inventor)

    2002-01-01

    Visible light emission is obtained from a plasma containing elemental barium including neutral barium atoms and barium ion species. Neutral barium provides a strong green light emission in the center of the visible spectrum with a highly efficient conversion of electrical energy into visible light. By the selective excitation of barium ionic species, emission of visible light at longer and shorter wavelengths can be obtained simultaneously with the green emission from neutral barium, effectively providing light that is visually perceived as white. A discharge vessel contains the elemental barium and a buffer gas fill therein, and a discharge inducer is utilized to induce a desired discharge temperature and barium vapor pressure therein to produce from the barium vapor a visible light emission. The discharge can be induced utilizing a glow discharge between electrodes in the discharge vessel as well as by inductively or capacitively coupling RF energy into the plasma within the discharge vessel.

  16. Evidence for a copper-dependent iron transport system in the marine, magnetotactic bacterium strain MV1

    Microsoft Academic Search

    Bradley L. Dubbels; Alan A. DiSpirito; John D. Morton; Jeremy D. Semrau; J. N. E. Neto; Dennis A. Bazylinski

    2004-01-01

    Cells of the magnetotactic marine vibrio, strain MV-1, produce magnetite-containing magnetosomes when grown anaerobically or microaerobically. Stable, spontaneous, non-magnetotactic mutants were regularly observed when cells of MV-1 were cultured on solid media incubated under anaerobic or microaerobic conditions. Randomly amplified polymorphic DNA analysis showed that these mutants are not all genetically identical. Cellular iron content of one non-magnetotactic mutant strain,

  17. Measurement of fast-neutron activation cross sections for copper, europium, hafnium, iron, nickel, silver, terbium and titanium at 10.0 and 14.7 MeV and for the Be( d, n) thick-target spectrum

    Microsoft Academic Search

    J. W. Meadows; D. L. Smith; L. R. Greenwood; R. C. Haight; Y. Ikeda; C. Konno

    1996-01-01

    Several fast-neutron activation reactions for copper, europium, hafnium, iron, nickel, silver, terbium and titanium that are important to fusion energy have been investigated in three distinct neutron fields generated by accelerators at Argonne National Laboratory (ANL) and Los Alamos National Laboratory (LANL), U.S.A., and Japan Atomic Energy Research Institute (JAERI), Tokai, Japan. The experimental data acquired from this collaboration, which

  18. Helium production by 9.85MeV neutrons in elemental iron, nickel, and copper and in ⁵⁶Fe and {sup 58,60,61}Ni

    Microsoft Academic Search

    R. C. Haight; D. W. Kneff; B. M. Oliver; L. R. Greenwood; H. Vonach

    1996-01-01

    Neutron-induced helium production, which can contribute substantially to radiation damage, is an important parameter in the choice of structural materials and other component materials for both fusion and fission reactors. Here, helium production cross sections for the elements iron, nickel, and copper and for the isotopes ⁵⁶Fe, ⁵⁸Ni, ⁶°Ni, and ⁶¹Ni for 9.85-MeV neutrons have been measured by irradiation with

  19. Identification of Negative cis-Acting Elements in Response to Copper in the Chloroplastic Iron Superoxide Dismutase Gene of the Moss Barbula unguiculata1

    PubMed Central

    Nagae, Miwa; Nakata, Masaru; Takahashi, Yohsuke

    2008-01-01

    Superoxide dismutases (SODs) are ubiquitous metalloenzymes that catalyze the dismutation of superoxide radicals. Chloroplasts have two isozymes, copper/zinc SOD (Cu/ZnSOD) and iron SOD (FeSOD), encoded by nuclear genes. Because bryophytes are considered as the earliest land plants, they are one of the most interesting plant models for adaptation against oxidative stress. In a previous study, we found that the FeSOD gene was expressed under Cu-deficient conditions and repressed under high-Cu-supply conditions; on the other hand, the Cu/ZnSOD gene was induced by Cu in a moss, Barbula unguiculata. The expression of Cu/ZnSOD and FeSOD is coordinately regulated at the transcriptional level depending on metal bioavailability. Here, using transgenic moss plants, we determined that the GTACT motif is a negative cis-acting element of the moss FeSOD gene in response to Cu. Furthermore, we found that a plant-specific transcription factor, PpSBP2 (for SQUAMOSA promoter-binding protein), and its related proteins bound to the GTACT motif repressed the expression of the FeSOD gene. The moss FeSOD gene was negatively regulated by Cu in transgenic Nicotiana tabacum plants, and the Arabidopsis thaliana FeSOD gene promoter containing the GTACT motif was repressed by Cu. Our results suggested that molecular mechanisms of GTACT motif-dependent transcriptional suppression by Cu are conserved in land plants. PMID:18258690

  20. Identification of negative cis-acting elements in response to copper in the chloroplastic iron superoxide dismutase gene of the moss Barbula unguiculata.

    PubMed

    Nagae, Miwa; Nakata, Masaru; Takahashi, Yohsuke

    2008-04-01

    Superoxide dismutases (SODs) are ubiquitous metalloenzymes that catalyze the dismutation of superoxide radicals. Chloroplasts have two isozymes, copper/zinc SOD (Cu/ZnSOD) and iron SOD (FeSOD), encoded by nuclear genes. Because bryophytes are considered as the earliest land plants, they are one of the most interesting plant models for adaptation against oxidative stress. In a previous study, we found that the FeSOD gene was expressed under Cu-deficient conditions and repressed under high-Cu-supply conditions; on the other hand, the Cu/ZnSOD gene was induced by Cu in a moss, Barbula unguiculata. The expression of Cu/ZnSOD and FeSOD is coordinately regulated at the transcriptional level depending on metal bioavailability. Here, using transgenic moss plants, we determined that the GTACT motif is a negative cis-acting element of the moss FeSOD gene in response to Cu. Furthermore, we found that a plant-specific transcription factor, PpSBP2 (for SQUAMOSA promoter-binding protein), and its related proteins bound to the GTACT motif repressed the expression of the FeSOD gene. The moss FeSOD gene was negatively regulated by Cu in transgenic Nicotiana tabacum plants, and the Arabidopsis thaliana FeSOD gene promoter containing the GTACT motif was repressed by Cu. Our results suggested that molecular mechanisms of GTACT motif-dependent transcriptional suppression by Cu are conserved in land plants. PMID:18258690

  1. Determination of copper, iron, nickel and zinc in ethanol fuel by energy dispersive X-ray fluorescence after pre-concentration on chromatography paper.

    PubMed

    Teixeira, Leonardo Sena Gomes; Santos, Elenir Souza; Nunes, Luana Sena

    2012-04-13

    This paper presents an alternative analytical method employing energy dispersive X-ray fluorescence (EDXRF) to determine copper, iron, nickel and zinc ions in ethanol fuel samples after a pre-concentration procedure. Our pre-concentration strategy utilizes analyte retention on cation exchange chromatography paper, a convenient substrate for direct EDXRF measurements. The repeatability, expressed in terms of RSD of standard solutions containing 0.25 ?g mL(-1) of Cu, Fe, Ni and Zn, and calculated from fifteen consecutive measurements, was 2.5, 2.8, 3.0, and 2.7%, respectively. The limits of detection (LOD), defined as the analyte concentration that gives a response equivalent to three times the standard deviation of the blank (n=10), were found to be 13, 15, 15 and 12 ?g L(-1) for Cu, Fe, Ni and Zn, respectively. The proposed method was applied to Cu, Fe, Ni and Zn determination in hydrated ethanol fuel samples collected from different gas stations. PMID:22444531

  2. Stochastic statistical theory of nucleation and evolution of nano-sized precipitates in alloys with application to precipitation of copper in iron

    SciTech Connect

    Khromov, K. Yu. [Russian Research Center 'Kurckatov Institute' (Russian Federation); Soisson, F. [DMN-SRMP, Service de Recherches de Metallurgie Physique (France); Stroev, A. Yu.; Vaks, V. G., E-mail: vaks@mbslab.kiae.ru [Russian Research Center 'Kurckatov Institute' (Russian Federation)

    2011-03-15

    A consistent and computationally efficient stochastic statistical approach (SSA) is developed to study the kinetics of nucleation and evolution of nano-sized precipitates in alloys. To increase the accuracy of the method, many refinements of the previous simplified versions of this approach have been made. We consider a realistic vacancy-mediated exchange kinetics rather than the simplified direct-atomic-exchange model; use quantitative, cluster statistical methods rather than simple mean-field-type approximations; allow strong concentration and temperature dependences of generalized mobilities in the resulting kinetic equations; consider realistic alloy models based on first-principle calculations, and so on. We also introduce the 'maximum thermodynamic gain' principle to determine the key kinetic parameter of the SSA, the characteristic length of local equilibrium in the course of the nucleation process. For several realistic models of iron-copper alloys studied, the results of the SSA-based simulations of precipitation kinetics made in this work agree well with the kinetic Monte Carlo simulation results for all main characteristics of the microstructure. The approach developed is also used to study the kinetics of nucleation and changes in microstructural evolution under variations of temperature or concentration.

  3. Interaction between Barium Oxide and Barium Containing Chloride Melt

    NASA Astrophysics Data System (ADS)

    Nikolaeva, Elena V.; Zakiryanova, Irina D.; Korzun, Iraida V.; Bovet, Andrey L.; Antonov, Boris D.

    2015-05-01

    Thermal analysis was applied to determine the liquidus temperatures in the NaCl-KCl-BaCl2-BaO system, with BaO concentration varied from 0 to 6 mole%. The temperature dependence of the BaO solubility in the NaCl-KCl-BaCl2 eutectic melt was investigated; the thermodynamic parameters of BaO dissolution were calculated. The caloric effects of melting of the NaCl-KCl-BaCl2 eutectic with barium oxide and barium oxychloride additions were studied. The type, morphology, and composition of oxychloride ionic groupings in the melt were determined in situ using Raman spectroscopy.

  4. The SLC31 (Ctr) copper transporter family

    Microsoft Academic Search

    Michael J. Petris

    2004-01-01

    Copper is essential for many copper-dependent processes, including mitochondrial oxidative phosphorylation, free-radical detoxification, pigmentation, neurotransmitter synthesis, and iron metabolism. The identification of proteins for high affinity copper uptake and export has greatly expanded our understanding of cellular copper homeostasis. Copper export in human cells is mediated by the ATP7A and ATP7B P-type ATPases, which are, respectively, affected in the genetic

  5. Barium Stars and Thermohaline Mixing

    SciTech Connect

    Husti, Laura [Dipartimento di Fisica Generale, Universita di Torino, Via Pietro Giuria 1, 10125 Turin (Italy)

    2008-01-24

    Barium stars are formed in binary systems through mass transfer from the carbon and s-element rich primary in the AGB phase, to the secondary star which is in a less evolved evolutionary stage. The mixing of the accreted material from the AGB donor with the envelope of the secondary results in a dilution of the s-element abundances. Dilution in red giants is explained by the occurence of the first dredge up, while in case of dwarfs thermohaline mixing would determine it. A comparison between the theoretical predictions of the AGB stellar models and the spectroscopical observations of a large sample of barium stars has been made. Dilution due to thermohaline mixing was taken into account when searching for best fits of the observational data. The importance of thermohaline mixing in barium dwarfs is discussed.

  6. Opacity of iron, nickel, and copper plasmas in the x-ray wavelength range: Theoretical interpretation of 2p-3d absorption spectra

    SciTech Connect

    Blenski, T.; Loisel, G.; Poirier, M.; Thais, F.; Arnault, P.; Caillaud, T.; Fariaut, J.; Gilleron, F.; Pain, J.-C.; Porcherot, Q.; Reverdin, C.; Silvert, V.; Villette, B.; Bastiani-Ceccotti, S.; Turck-Chieze, S.; Foelsner, W.; Gaufridy de Dortan, F. de [CEA, IRAMIS, Service 'Photons, Atomes et Molecules', Centre d'Etudes de Saclay, F-91191 Gif-sur-Yvette Cedex (France); CEA, DAM, DIF, F-91297 Arpajon (France); LULI, UMR No. 7605 CNRS - Ecole Polytechnique, F-91128 Palaiseau Cedex (France); CEA, IRFU, Service d'Astrophysique, Centre d'Etudes de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Institute of Nuclear Fusion, Universidad Politecnica de Madrid, Spain and Laboratoire d'Optique Appliquee, ENSTA-Paritech-Polytechnique, Chemin de la Huniere, F-91671 Palaiseau (France)

    2011-09-15

    This paper deals with theoretical studies on the 2p-3d absorption in iron, nickel, and copper plasmas related to LULI2000 (Laboratoire pour l'Utilisation des Lasers Intenses, 2000J facility) measurements in which target temperatures were of the order of 20 eV and plasma densities were in the range 0.004-0.01 g/cm{sup 3}. The radiatively heated targets were close to local thermodynamic equilibrium (LTE). The structure of 2p-3d transitions has been studied with the help of the statistical superconfiguration opacity code sco and with the fine-structure atomic physics codes hullac and fac. A new mixed version of the sco code allowing one to treat part of the configurations by detailed calculation based on the Cowan's code rcg has been also used in these comparisons. Special attention was paid to comparisons between theory and experiment concerning the term features which cannot be reproduced by sco. The differences in the spin-orbit splitting and the statistical (thermal) broadening of the 2p-3d transitions have been investigated as a function of the atomic number Z. It appears that at the conditions of the experiment the role of the term and configuration broadening was different in the three analyzed elements, this broadening being sensitive to the atomic number. Some effects of the temperature gradients and possible non-LTE effects have been studied with the help of the radiative-collisional code scric. The sensitivity of the 2p-3d structures with respect to temperature and density in medium-Z plasmas may be helpful for diagnostics of LTE plasmas especially in future experiments on the {Delta}n=0 absorption in medium-Z plasmas for astrophysical applications.

  7. Iron, copper, zinc and bromine mapping in cirrhotic liver slices from patients with hemochromatosis studied by microscopic synchrotron radiation X-ray fluorescence analysis in continuous scanning mode

    NASA Astrophysics Data System (ADS)

    Osterode, W.; Falkenberg, G.; Höftberger, R.; Wrba, F.

    2007-07-01

    Iron (Fe) and copper (Cu) are essential metals in physiological cell metabolism. While Fe is easy to determine biochemically in histological slices, Cu and zinc (Zn) distribution is frequently critical in confirming the presence of an overload in disturbed Fe/Cu metabolism. To analyze Fe, Cu and Zn in a near histological resolution, energy dispersive microscopic synchrotron radiation X-ray fluorescence was applied. In normal liver tissue, after fixation and imbedding in paraffin, mean Fe, Cu and Zn concentrations were 152 ± 54, 20.1 ± 4.3 and 88.919.5 ?g/g sample weight, respectively. No substantial, characteristic differences in their distribution were found in the two-dimensional scans. In slices from patients with hemochromatosis mean Fe, Cu and Zn concentrations were 1102 ± 539, 35.9 ± 14.6 and 27.2 ± 6.7 ?g/g sample weight, respectively. Additionally, a significant decrease in phosphorus and sulphur concentrations existed. An increased Cu around cirrhotic regenerations nodules is mostly associated with a lymphocytic infiltration in this region. Analyzing concentrations of Fe in different regions of the samples show a clear negative dependency between Fe and Cu, Cu and Zn, but a positive one between Fe and Zn. Conclusion: With a focal beam size of 15 ?m in diameter a resolution of the elemental distribution was achieved which is widely comparable with stained histological slices (20× light microscope). The analysis of simultaneous determined elements reveals metabolic differences between Fe, Cu and Zn in liver tissue from patients with hemochromatosis.

  8. Comparison of Barium and Arsenic Concentrations in Well Drinking Water and in Human Body Samples and a Novel Remediation System for These Elements in Well Drinking Water.

    PubMed

    Kato, Masashi; Kumasaka, Mayuko Y; Ohnuma, Shoko; Furuta, Akio; Kato, Yoko; Shekhar, Hossain U; Kojima, Michiyo; Koike, Yasuko; Dinh Thang, Nguyen; Ohgami, Nobutaka; Ly, Thuy Bich; Jia, Xiaofang; Yetti, Husna; Naito, Hisao; Ichihara, Gaku; Yajima, Ichiro

    2013-01-01

    Health risk for well drinking water is a worldwide problem. Our recent studies showed increased toxicity by exposure to barium alone (?700 µg/L) and coexposure to barium (137 µg/L) and arsenic (225 µg/L). The present edition of WHO health-based guidelines for drinking water revised in 2011 has maintained the values of arsenic (10 µg/L) and barium (700 µg/L), but not elements such as manganese, iron and zinc. Nevertheless, there have been very few studies on barium in drinking water and human samples. This study showed significant correlations between levels of arsenic and barium, but not its homologous elements (magnesium, calcium and strontium), in urine, toenail and hair samples obtained from residents of Jessore, Bangladesh. Significant correlation between levels of arsenic and barium in well drinking water and levels in human urine, toenail and hair samples were also observed. Based on these results, a high-performance and low-cost adsorbent composed of a hydrotalcite-like compound for barium and arsenic was developed. The adsorbent reduced levels of barium and arsenic from well water in Bangladesh and Vietnam to <7 µg/L within 1 min. Thus, we have showed levels of arsenic and barium in humans and propose a novel remediation system. PMID:23805262

  9. Iron, manganese and copper concentrations in wet precipitations and kinetics of the oxidation of SO 2 in rain water at two urban sites, Jaipur and Kota, in Western India

    NASA Astrophysics Data System (ADS)

    Manoj, S. V.; Mishra, C. D.; Sharma, M.; Rani, A.; Jain, R.; Bansal, S. P.; Gupta, K. S.

    Rain-water samples were collected from Jaipur and Kota in Western India during the monsoon seasons of 1996-1999. In all cases, the pH of rain-water samples exceeded 7.0 and fell in the range (7.1-8.5). In view of the fact that the trace metals particularly iron, manganese and copper have been held responsible for the catalytic activity of rain-water, the chemical analysis of the collected samples was done with regard to the concentrations of these metals. The kinetics of autoxidation of SO 2 has been studied using rain-water samples as medium.

  10. 40 CFR 721.10011 - Barium calcium manganese strontium oxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

  11. 40 CFR 721.10011 - Barium calcium manganese strontium oxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

  12. 40 CFR 721.10011 - Barium calcium manganese strontium oxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

  13. 40 CFR 721.10011 - Barium calcium manganese strontium oxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

  14. Are There Any Stars Lacking Neutron-Capture Elements? Evidence from Strontium and Barium

    E-print Network

    Roederer, Ian U

    2012-01-01

    The cosmic dispersion in the abundances of the heavy elements strontium and barium in halo stars is well known. Strontium and barium are detected in most cool, metal-poor giants, but are these elements always detectable? To identify stars that could be considered probable candidates for lacking these elements, I examine the stellar abundance data available in the literature for 1148 field stars and 226 stars in dwarf galaxies, 776 of which have metallicities lower than [Fe/H]Strontium or barium have been detected in all field, globular cluster, and dwarf galaxy environments studied. All upper limits are consistent with the lowest detected ratios of [Sr/H] and [Ba/H]. The frequent appearance of these elements raises the intriguing prospect that at least one kind of neutron-capture reaction operates as often as the nucleosynthesis mechanisms that produce lighter elements, like magnesium, calcium, or iron, although the yields of heavy elements may be more variable.

  15. Chemical compositions of four barium stars

    E-print Network

    Liang, Y C; Chen, Y Q; Qiu, H M; Zhang, B

    2003-01-01

    Chemical compositions of four barium stars HD 26886, HD 27271, HD 50082 and HD 98839 are studied based on high resolution, high signal-to-noise Echelle spectra. Results show that all of them are disk stars. Their \\alpha and iron peak elements are similar to the solar abundances. The neutron-capture process elements are overabundant relative to the Solar. The heavy-element abundances of the strong Ba star HD 50082 are higher than those of other three mild Ba stars. Its mass is 1.32Msun (+0.28,-0.22Msun), and is consistent with the average mass of strong Ba stars (1.5Msun). For mild Ba star HD 27271 and HD 26886, the derived masses are 1.90Msun (+0.25,-0.20Msun) and 2.78Msun (+0.75,-0.78M_sun), respectively, which are consistent with the average mass of mild Ba stars. We also calculate the theoretical abundances of Ba stars by combining the AGB stars nucleosynthesis and wind accretion formation scenario of Ba binary systems. The comparisons between the observed abundance patterns of the sample stars with the th...

  16. Effect of dietary Garcinia cambogia extract on serum essential minerals (calcium, phosphorus, magnesium) and trace elements (iron, copper, zinc) in rats fed with high-lipid diet.

    PubMed

    Gürsel, Feraye Esen; Ate?, Atila; Bilal, Tanay; Altiner, Ay?en

    2012-09-01

    The aim of the study was to investigate the effect of Garcinia cambogia extract on serum calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe), zinc (Zn) and copper (Cu) concentrations in rats fed with the normal or the high-lipid and -cholesterol diet. Thirty 1-year-old female Sprague-Dawley rats (pathogen-free), weighing an average of 229 g, were randomly assigned to three experimental groups of ten animals each. Diets and tap water were given ad libitum for 75 days. Group 1 (control group) was fed with basal diet (2 % liquid vegetable oil, 0 % cholesterol), while the diets of groups 2 and 3 contained vegetable oil (2 % liquid vegetable oil and 5 % hydrogenated vegetable oil) and cholesterol (3 %) in high levels. 4,5 % G. cambogia extract containing 65 % HCA was added to the diet of group 3 as from day 45. Blood samples were withdrawn on days 0, 45 and 75. Serum mineral levels were analyzed using standard enzymatic colorimetric methods with a spectrophotometer. All significant differences were p<0.05. Serum Ca levels were not significantly different between all groups on days 45 and 75. Serum P level was significantly higher in the group fed with high-lipid diet and G. cambogia extract than in the control group on day 45. Serum Mg level was significantly higher in group 2 than in the control group on day 45. Serum Fe levels were significantly lower in the control group than in the other groups on days 45 and 75. Serum Zn level of the group fed with high-lipid diet and G. cambogia extract was significantly higher than in the control group on day 75. Serum Cu levels were significantly higher in group 2 than in the control group, and in group 3 than in group 2 on day 75. In conclusion, a diet containing the high fat amounts may lead to the increase in circular levels of some minerals due to the short-chain fatty acid production lowering the luminal pH which increases mineral solubility, or serving as a fuel for mucosal cells and stimulating cell proliferation in the large intestine. G. cambogia extract may be used in the P and Cu deficiencies due to increases resulting in the present P and Cu amounts in G. cambogia extract, or the use of phytate P in diet. It was hoped that with further evidence-based study this product will enter to mainstream medicines. PMID:22419377

  17. Combined effects of hydrographic structure and iron and copper availability on the phytoplankton growth in Terra Nova Bay Polynya (Ross Sea, Antarctica)

    NASA Astrophysics Data System (ADS)

    Rivaro, Paola; Luisa Abelmoschi, Maria; Grotti, Marco; Ianni, Carmela; Magi, Emanuele; Margiotta, Francesca; Massolo, Serena; Saggiomo, Vincenzo

    2012-04-01

    Surface water (<100 m) samples were collected from the Terra Nova Bay polynya region of the Ross Sea (Antarctica) in January 2006, with the aim of evaluating the individual and combined effects of hydrographic structure, iron and copper concentration and availability on the phytoplankton growth. The measurements were conducted within the framework of the Climatic Long Term Interaction for the Mass-balance in Antarctica (CLIMA) Project of the Programma Nazionale di Ricerca in Antartide activities. Dissolved oxygen, nutrients, phytoplankton pigments and concentration and complexation of dissolved trace metals were determined. Experimental data were elaborated by Principal Component Analysis (PCA). As a result of solar heating and freshwater inputs from melting sea-ice, the water column was strongly stratified with an Upper Mixed Layer 4-16 m deep. The integrated Chl a in the layer 0-100 m ranged from 60 mg m-2 to 235 mg m-2, with a mean value of 138 mg m-2. The pigment analysis showed that diatoms dominated the phytoplankton assemblage. Major nutrients were generally high, with the lowest concentration at the surface and they were never fully depleted. The Si:N drawdown ratio was close to the expected value of 1 for Fe-replete diatoms. We evaluated both the total and the labile dissolved fraction of Fe and Cu. The labile fraction was operationally defined by employing the chelating resin Chelex-100, which retains free and loosely bound trace metal species. The total dissolved Fe ranged from 0.48 to 3.02 nM, while the total dissolved Cu from 3.68 to 6.84 nM. The dissolved labile Fe ranged from below the detection limit (0.15 nM) to 1.22 nM, and the dissolved labile Cu from 0.31 to 1.59 nM, respectively. The labile fractions measured at 20 m were significantly lower than values in 40-100 m samples. As two stations were re-sampled 5 days later, we evaluated the short-term variability of the physical and biogeochemical properties. In particular, in a re-sampled station at 20 m, the total dissolved Fe increased and the total dissolved Cu decreased, while their labile fraction was relatively steady. As a result of the increase in total Fe, the percentage of the labile Fe decreased. An increase of the Si:N, Si:P and Si:FUCO ratios was measured also in the re-sampled station. On this basis, we speculated that a switch from a Fe-replete to a Fe-deplete condition was occurring.

  18. Quantitative analysis of heavy metals emission during the combustion and baling of polyvinyl chloride insulated copper wire 

    E-print Network

    Pickard, David Paul

    1996-01-01

    such as calcium-zinc, barium- zinc, and barium-cadmium soaps, form the most homogenous group of compounds used in PVC stabilization. In the United States, mixed-metal combinations of lead, cadmium, barium, zinc, and other heavy metals represent the greatest.... 10 TABLE I Common Inorganic Pigments Containing Heavy Metals (22, 241 Inorganic Pigments Color or Hue Titanium Dioxide Zinc Oxide Lead Carbonate Lead Sulfate Iron Oxides Lead Chromates Lead Molybdate Orange Cadmium Nickel Antimony Titanium...

  19. REMOVAL OF BARIUM AND RADIUM FROM GROUNDWATER

    EPA Science Inventory

    A research project was undertaken to investigate processes for removing barium and radium from drinking water. Special emphasis was placed on ion exchange processes that can be used without adding large concentrations of sodium to the water. The wastes from radium and barium remo...

  20. Quantum manipulation on the Barium quadrupolar transition

    E-print Network

    Blatt, Rainer

    and stabilization of a new fiber laser system to ma- nipulate the Barium quadrupolar transition, with the aim . . . . . . . . . . . . . . . 55 6 Spectroscopy and sideband cooling on a single 138 Ba+ 58 6.1 Quantum jumps using the fiber laser . . . . . . . . . . . . .Quantum manipulation on the Barium quadrupolar transition A diploma thesis in physics submitted

  1. Examination of sulfur-functionalized, copper-doped iron nanoparticles for vapor-phase mercury capture in entrained-flow and fixed-bed systems

    Microsoft Academic Search

    D. E. Meyer; S. K. Sikdar; N. D. Hutson; D. Bhattacharyya

    2007-01-01

    The use of copper-doped Fe nanoaggregates silanized with organic sulfur as bis-(triethoxy silyl propyl)-tetra sulfide has been investigated for the capture of elemental mercury (Hg°) from the vapor phase for potential power plant applications. Silanization procedures resulted in 70% deposition of the targeted sulfur level, with particles containing approximately 4 wt % S. The addition of copper was found to

  2. Method for harvesting rare earth barium copper oxide single crystals

    DOEpatents

    Todt, V.R.; Sengupta, S.; Shi, D.

    1996-04-02

    A method of preparing high temperature superconductor single crystals is disclosed. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals of the high temperature superconductor, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals of the high temperature superconductor on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals melted, allowing the wicking away of the peritectic liquid. 2 figs.

  3. Formation and microwave absorption of barium and strontium ferrite prepared by sol-gel technique

    Microsoft Academic Search

    K. A. Hempel; D. Bonnenberg

    1993-01-01

    Ba and Sr ferrites are prepared by sol-gel technique with different Fe\\/Ba(Sr) ratios in the starting materials. Magnetization, coercive, and anisotropy field strength are determined depending on the heat treatment of the gel and the iron\\/barium(strontium) ratio in the starting material. A two-step heat treatment is used to prepare single-domain powders with high magnetization. These powders prepared by sol-gel technique

  4. Chemical compositions of four barium stars

    E-print Network

    Y. C. Liang; G. Zhao; Y. Q. Chen; H. M. Qiu; B. Zhang

    2003-12-15

    Chemical compositions of four barium stars HD 26886, HD 27271, HD 50082 and HD 98839 are studied based on high resolution, high signal-to-noise Echelle spectra. Results show that all of them are disk stars. Their \\alpha and iron peak elements are similar to the solar abundances. The neutron-capture process elements are overabundant relative to the Solar. The heavy-element abundances of the strong Ba star HD 50082 are higher than those of other three mild Ba stars. Its mass is 1.32Msun (+0.28,-0.22Msun), and is consistent with the average mass of strong Ba stars (1.5Msun). For mild Ba star HD 27271 and HD 26886, the derived masses are 1.90Msun (+0.25,-0.20Msun) and 2.78Msun (+0.75,-0.78M_sun), respectively, which are consistent with the average mass of mild Ba stars. We also calculate the theoretical abundances of Ba stars by combining the AGB stars nucleosynthesis and wind accretion formation scenario of Ba binary systems. The comparisons between the observed abundance patterns of the sample stars with the theoretical results show that wind accretion scenario can explain the abundance patterns of HD 50082 and HD 27271 well, but fail to explain the abundances of HD 26886. It means that the mild Ba star HD 26886, with shorter orbital period (P11000 d), may be either a star with the heavy elements enriched by itself or a "true Ba" star.

  5. Copper Efflux Is Induced during Anaerobic Amino Acid Limitation in Escherichia coli To Protect Iron-Sulfur Cluster Enzymes and Biogenesis

    PubMed Central

    Fung, Danny Ka Chun; Lau, Wai Yin; Chan, Wing Tat

    2013-01-01

    Adaptation to changing environments is essential to bacterial physiology. Here we report a unique role of the copper homeostasis system in adapting Escherichia coli to its host-relevant environment of anaerobiosis coupled with amino acid limitation. We found that expression of the copper/silver efflux pump CusCFBA was significantly upregulated during anaerobic amino acid limitation in E. coli without the supplement of exogenous copper. Inductively coupled plasma mass spectrometry analysis of the total intracellular copper content combined with transcriptional assay of the PcusC-lacZ reporter in the presence of specific Cu(I) chelators indicated that anaerobic amino acid limitation led to the accumulation of free Cu(I) in the periplasmic space of E. coli, resulting in Cu(I) toxicity. Cells lacking cusCFBA and another copper transporter, copA, under this condition displayed growth defects and reduced ATP production during fumarate respiration. Ectopic expression of the Fe-S cluster enzyme fumarate reductase (Frd), or supplementation with amino acids whose biosynthesis involves Fe-S cluster enzymes, rescued the poor growth of ?cusC cells. Yet, Cu(I) treatment did not impair the Frd activity in vitro. Further studies revealed that the alternative Fe-S cluster biogenesis system Suf was induced during the anaerobic amino acid limitation, and ?cusC enhanced this upregulation, indicating the impairment of the Fe-S cluster assembly machinery and the increased Fe-S cluster demands under this condition. Taken together, we conclude that the copper efflux system CusCFBA is induced during anaerobic amino acid limitation to protect Fe-S cluster enzymes and biogenesis from the endogenously originated Cu(I) toxicity, thus facilitating the physiological adaptation of E. coli. PMID:23893112

  6. Growth-modulating tripeptide (glycylhistidyllysine): association with copper and iron in plasma, and stimulation of adhesiveness and growth of hepatoma cells in culture by tripeptide-metal ion complexes.

    PubMed

    Pickart, L; Thaler, M M

    1980-02-01

    The tripeptide H-Gly-His-Lys-OH (GHL) is a human plasma constituent which has been previously shown to modulate the growth and viability of a variety of cell types and organisms. Experimental observations presented herein indicate that GHL is complexed with the transition metal ions Cu++ and Fe++ in vivo and may exert its biological effects as a peptide-metal chelate. At physiological pH in vitro, GHL associates with ionic copper, cobalt, iron, molybdenum, manganese, nickel, and zinc, but has no affinity for calcium, manganese, potassium, and sodium. GHL acts synergistically with copper, iron, cobalt, and zinc to alter patterns of cell growth in monolayer cultures of a tumorigenic hepatoma cell line (HTC4). These transition metals induce cellular flattening and adhesion to support surfaces, and inhibit DNA synthesis and lactic acid production when growth is limited by reduction of serum concentrations in medium. These inhibitory effects are neutralized, and intercellular adhesion and growth are stimulated by GHL in medium at nanomolar concentrations. Cu and Fe are the most active metals when combined with GHL. The results suggest that the inability of HTC4 cultures to replicate without adequate concentrations of serum in medium may reflect deficiency of GHL and transition metals, which appear to form complexes prior to interaction with cells. Chelation of transition metals with GHL and, potentially, with other growth-modulating peptide factors in plasma or medium, may provide a mechanism for expression and regulation of biological activities influenced by transition metals and polypeptide growth factors. The observed effects of GHL-metal complexes, including stimulation of cellular adhesiveness to substratum (flattening) and intercellular attachment (monolayer formation), appear to satisfy requirements for growth of hepatoma cells in monolayer culture. PMID:6246126

  7. Barium ions for quantum computation

    NASA Astrophysics Data System (ADS)

    Dietrich, Matthew

    Barium ion is investigated as a hyperfine qubit. 137Ba + is trapped in a linear Paul trap and laser cooled. Isotope selective photoionization is employed to improve trapping from an isotopically inpure source. Optical pumping into the magnetically insensitive 2S 1/2(F=2) mF = 0 state is shown, and readout by electron shelving into the 2D5/2 is demonstrated both directly and by adiabatic passage. Rabi flops between the 2S1/2 F=1 and F=2 states is accomplished by exposure to 8.037 GHz microwave radiation. Several methods of locking the cooling lasers have been attempted and are discussed. Stabilization of the infrared laser used to drive the D 5/2 ? S1/2 transition is of particular interest, and several novel technologies are tested in this purpose.

  8. Copper and zinc recycling from copper alloys` spent pickling solutions

    SciTech Connect

    Roman-Moguel, G.J.; Plascencia, G.; Perez, J.

    1995-12-31

    The precipitation of copper and zinc as cements from a copper alloys` spent pickling solution has been studied at laboratory and pilot scale, with the objective of designing an economic process to recover both metals and render a solution to be either recycled to the pickling process or treated in a standard fashion and produce a non-hazardous sludge. The sulfuric acid spent pickling solution already containing copper and zinc was used first to dissolve another solid residue originated in the copper alloys foundry to neutralize part of the acidity. The resulting enriched solution was treated separately with two reductants: sodium borohydride and iron powder varying pH and excess of reductant under constant agitation. Under the best conditions, precipitation of over 95 percent of zinc and copper was achieved together with the reduction of lead and cadmium contents respectively. A process for the combined residues treatment is proposed.

  9. Barium Ions for Quantum Computation Matthew Dietrich

    E-print Network

    Blinov, Boris

    Barium Ions for Quantum Computation Matthew Dietrich A dissertation submitted in partial for Quantum Computation Matthew Dietrich Chair of the Supervisory Committee: Assistant Professor Boris Blinov trap and laser cooled. Isotope selective photoionization is employed to improve trapping from

  10. Dielectric and Piezoelectric Properties of Barium Titanate

    Microsoft Academic Search

    Shepard Roberts

    1947-01-01

    The dielectric constant and loss of barium titanate and barium-strontium titanate have been measured at biasing field strengths from 0 to 5 megavolts per meter, at temperatures from -50°C to +135°C and at frequencies from 0.1 to 25 megacycles. The measurements versus temperature indicate the expected agreement with the Curie-Weiss law at temperatures above the Curie point. Measurements versus field

  11. Impact of vanadium ions in barium borate glass

    NASA Astrophysics Data System (ADS)

    Abdelghany, A. M.; Hammad, Ahmed H.

    2015-02-01

    Combined optical and infrared spectral measurements of prepared barium borate glasses containing different concentrations of V2O5 were carried out. Vanadium containing glasses exhibit extended UV-visible (UV/Vis.) bands when compared with base binary borate glass. UV/Vis. spectrum shows the presence of an unsymmetrical strong UV broad band centered at 214 nm attributed to the presence of unavoidable trace iron impurities within the raw materials used for the preparation of such glass. The calculated direct and indirect optical band gaps are found to decrease with increasing the vanadium content (2.9:137 for indirect and 3.99:2.01 for direct transition). This change was discussed in terms of structural changes in the glass network. Infrared absorption spectra of the glasses reveal the appearance of both triangular and tetrahedral borate units. Electron spin resonance analyses indicate the presence of unpaired species in sufficient quantity to be identified and to confirm the spectral data.

  12. Copper stabilizes the Menkes copper-transporting ATPase (Atp7a) protein expressed in rat intestinal epithelial cells.

    PubMed

    Xie, Liwei; Collins, James F

    2013-02-01

    Iron deficiency decreases oxygen tension in the intestinal mucosa, leading to stabilization of hypoxia-inducible transcription factor 2? (Hif2?) and subsequent upregulation of genes involved in iron transport [e.g., divalent metal transporter (Dmt1) and ferroportin 1 (Fpn1)]. Iron deprivation also alters copper homeostasis, reflected by copper accumulation in the intestinal epithelium and induction of an intracellular copper-binding protein [metallothionein (Mt)] and a copper exporter [Menkes copper ATPase (Atp7a)]. Importantly, Atp7a is also a Hif2? target. It was, however, previously noted that Atp7a protein expression was induced more strongly than mRNA in the duodenum of iron-deprived rats, suggesting additional regulatory mechanisms. The current study was thus designed to decipher mechanistic aspects of Atp7a regulation during iron deprivation using an established in vitro model of the mammalian intestine, rat intestinal epithelial (IEC-6) cells. Cells were treated with an iron chelator and/or copper loaded to mimic the in vivo situation. IEC-6 cells exposed to copper showed a dose-dependent increase in Mt expression, confirming intracellular copper accumulation. Iron chelation with copper loading increased Atp7a mRNA and protein levels; however, contrary to our expectation, copper alone increased only protein levels. This suggested that copper increased Atp7a protein levels by a posttranscriptional regulatory mechanism. Therefore, to determine if Atp7a protein stability was affected, the translation inhibitor cycloheximide was utilized. Experiments in IEC-6 cells revealed that the half-life of the Atp7a protein was ~41 h and, furthermore, that intracellular copper accumulation increased steady-state Atp7a protein levels. This investigation thus reveals a novel mechanism of Atp7a regulation in which copper stabilizes the protein, possibly complementing Hif2?-mediated transcriptional induction during iron deficiency. PMID:23174565

  13. Selective adsorption of lead, copper and antimony in runoff water from a small arms shooting range with a combination of charcoal and iron hydroxide.

    PubMed

    Mariussen, Espen; Johnsen, Ida Vaa; Strømseng, Arnljot Einride

    2015-03-01

    Metals and metalloids from ammunition residues at small arms shooting ranges leach into the soil and surrounding watercourses and may pose a threat to exposed wildlife and humans. To reduce the potential impact of heavy metal on the environment a field study was performed with different sorbents in order to reduce the metal concentration in polluted water from a shooting range. Two sorbents were tested in situ for their ability to reduce the concentration of Cu, Sb and Pb: Brimac(®) charcoal and Kemira(®) iron hydroxide. The mean sorption of Cu, Sb and Pb was 85%, 65%, and 88% respectively when using the charcoal and 60%, 85% and 92% respectively with the iron hydroxide. Even better sorption of the elements was achieved when the two sorbents were combined in order to increase their selectivity. The best results were achieved in the filter in which the water percolated the charcoal first and the iron hydroxide last, with a mean sorption of Cu, Sb and Pb of 89%, 90% and 93% respectively. This preparation gave a significant better sorption of Cu compared to the filter in which the water percolated the iron hydroxide first and the charcoal last. The different effect between the two filters may be due to pH, since charcoal has alkaline properties and iron hydroxide has acidic properties. For large scale experiments or in filter devices we therefore recommend use of a combination of different reactive sorbents. PMID:25527987

  14. Yellow discoloration in veal calves: the role of hepatic copper.

    PubMed

    Groot, M J; Gruys, E

    1993-02-13

    Liver samples from four groups of calves were analysed chemically and histologically for copper and iron levels. Milk replacer-fed 'yellow' calves were compared with milk replacer-fed 'white' calves, concentrate and silage-fed 'pink' calves and concentrate and silage-fed young 'red' fattening bulls. In the milk replacer-fed calves high copper and low iron levels were measured in the liver, whereas in the concentrate and silage fed pink calves and fattening bulls lower copper and higher iron levels were found. The yellow calves appeared to be icteric and had chronic hepatitis. Their hepatic histopathology was characterised by fibrosis, cirrhosis, fatty change, increased amounts of stainable copper, necrobiosis and prominent cholestasis; some animals had intranuclear inclusion bodies in the hepatocytes. They had similar or lower hepatic copper levels than the white calves and varying iron levels, indicating that copper toxicity was not the primary cause of the hepatic damage. PMID:8456546

  15. Copper complexation by siderophores from filamentous blue-green algae

    Microsoft Academic Search

    DIANE M. MCKNIGHT; FRANCOIS M. M. MOREL

    1980-01-01

    From our experimental evidence that iron lirnitation greatly increases the extracellular concentration of strong copper-complexing agents in cultures of Anabaena flos-aquae and Anabaena cyhdrica, and that the iron-algal exudate complex is much more stable than the copper complex, we conclude that strong copper-complexing agents released by filamentous blue-green algae are siderophores. Further experiments demonstrate that siderophore excre- tion is not

  16. Specific-Heat of High-Temperature Superconductors: Apparatus and Measurements (magnetic Field, Yttrium Barium Copper Oxide, Mercury Barium Copper Oxide, Barium Potassium Bismuth Oxide

    Microsoft Academic Search

    Brian Fred Woodfield

    1995-01-01

    An apparatus has been designed and constructed capable of measuring the specific heat from 0.6 K to 130 K using a variety of specific-heat techniques in magnetic fields as high as 9 T. The apparatus contains a temperature -controlled block with reference thermometers shielded from the magnetic field to allow precise calibrations of the working thermometers in a magnetic field.

  17. The ubiquity of iron.

    PubMed

    Frey, Perry A; Reed, George H

    2012-09-21

    The importance of iron in living systems can be traced to the many complexes within which it is found, to its chemical mobility in undergoing oxidation-reduction reactions, and to the abundance of iron in Earth's crust. Iron is the most abundant element, by mass, in the Earth, constituting about 80% of the inner and outer cores of Earth. The molten outer core is about 8000 km in diameter, and the solid inner core is about 2400 km in diameter. Iron is the fourth most abundant element in Earth's crust. It is the chemically functional component of mononuclear iron complexes, dinuclear iron complexes, [2Fe-2S] and [4Fe-4S] clusters, [Fe-Ni-S] clusters, iron protophorphyrin IX, and many other complexes in protein biochemistry. Metals such as nickel, cobalt, copper, and manganese are present in the crust and could in principle function chemically in place of iron, but they are scarce in Earth's crust. Iron is plentiful because of its nuclear stability in stellar nuclear fusion reactions. It seems likely that other solid planets, formed by the same processes as Earth, would also foster the evolution of life and that iron would be similarly important to life on those planets as it is on Earth. PMID:22845493

  18. Temperature-dependent coherent oscillation in photorefractive relaxor strontium barium

    E-print Network

    Osnabrück, Universität

    Temperature-dependent coherent oscillation in photorefractive relaxor strontium barium niobate M of the photorefractive light-induced scattering (beam fanning) in Sr0.61Ba0.39Nb2O6 (strontium barium niobate) doped

  19. Examination of sulfur-functionalized, copper-doped iron nanoparticles for vapor-phase mercury capture in entrained-flow and fixed-bed systems

    SciTech Connect

    D.E. Meyer; S.K. Sikdar; N.D. Hutson; D. Bhattacharyya [University of Kentucky, Lexington, KY (United States). Department of Chemical and Materials Engineering

    2007-09-15

    The use of copper-doped Fe nanoaggregates silanized with organic sulfur as bis-(triethoxy silyl propyl)-tetra sulfide has been investigated for the capture of elemental mercury (Hg{sup 0}) from the vapor phase for potential power plant applications. Silanization procedures resulted in 70% deposition of the targeted sulfur level, with particles containing approximately 4 wt % S. The addition of copper was found to increase the fixed-bed (total) capacity of this type of sorbent from 170 {+-} {mu}20 g Hg{center_dot}g sorbent{sup -1} with no copper doping to 2730 {+-} 80 {mu}g Hg{center_dot}g sorbent{sup -1} at 1.2 wt % Cu. When no S is deposited, the capacity of Fe/Cu nanoaggregates was only 180 g Hg{center_dot}g sorbent{sup -1}. These findings suggest that a combined Cu-S mechanism is responsible for Hg capture. Moving-bed (injection) testing of the Fe-based sorbents in a simulated flue gas stream showed that the 1.2 wt % Cu sample was able to achieve significant removal of the Hg. At a modest sorbent injection rate of 3.6 x 10{sup -3} g{center_dot}L{sup -1}{center_dot}h{sup -1}, this material showed a steady-state removal capacity of 107.5 {mu}g Hg{center_dot}g sorbent{sup -1} for an inlet concentration of 17.8 {mu}g{center_dot}m{sup -3}. On the basis of only 4% usage of the total capacity during single-pass injection, it might be beneficial to develop methods to separate and recycle these materials to reduce power plant operation costs for Hg emissions control. 17 refs., 5 figs., 10 tabs.

  20. Preparation and Properties of Barium Titanate Nanopowder\\/Epoxy Composites

    Microsoft Academic Search

    J. Chandradass; Dong-sik Bae

    2008-01-01

    This article is focused on the preparation of barium titanate nanopowder\\/epoxy composites and studying the effect of barium titanate nanopowder on improving mechanical and thermal characteristics of the epoxy polymer. Composites are prepared by dispersing barium titanate nanopowder in epoxy resin and, subsequently, cross-linking by using diamino diphenyl methane (DDM) curing agents. Synthesis of barium titanate nanopowder\\/epoxy composites is carried

  1. Ordered substitution of iron for copper in the tetragonal perovskite La{sub 6.4}Sr{sub 1.6}Cu{sub 8}O{sub 20}

    SciTech Connect

    Genouel, R.; Michel, C.; Nguyen, N.; Hervieu, M.; Raveau, B. [Universite de Caen (France)] [Universite de Caen (France)

    1995-03-01

    Two series of iron-substituted cuprates with the tetragonal La{sub 6.4}Sr{sub 1.6}Cu{sub 8}O{sub 20} oxygen deficient perovskite structure have been isolated: La{sub 6.4}Sr{sub 1.6}Cu{sub 8-x}Fe{sub x}O{sub 20} (0 {le} x {le} 1.20) and La{sub 6.4-x}Sr{sub 1.6+x}Cu{sub 8-x}Fe{sub x}O{sub 20} (0 {le} x {le} 2). The XRD and Moessbauer studies show that they correspond to a preferential substitution of Fe(III) for copper in the octahedral sites of the structure. In fact the ideal structure can be described as 90{degrees}-oriented {open_quotes}123{close_quotes} copper ribbons interconnected with [FeO{sub 3}]{infinity} rows of FeO{sub 6} octahedra. The transport properties of these phases show a transition from a metallic to a semiconducting state. The difference in behavior between the La{sub 6.4}Sr{sub 1.6}Cu{sub 8-x}Fe{sub x}O{sub 20} series and the La{sub 6.4-x}Sr{sub 1.6+x}Cu{sub 8-x}Fe{sub x}O{sub 20} series is interpreted on the basis of hole carrier density introduced by Cu(III) and of the trapping of carriers by Fe(III) species. The possibility of anisotropic transport properties with a metallic conductivity along c is discussed.

  2. Improved spectrophotometric analysis of barium styphnate

    SciTech Connect

    Brown, N E; Blasi, J A

    1983-01-01

    A spectrophotometric procedure to determine the purity of barium styphnate monohydrate based upon the absorbance of the styphnate ion at 326 and 413.3 nm has been developed. The purity is determined by comparing the absorbance of the styphnate ion in barium styphnate and in styphnic acid. Our investigation has shown that the molar absorptivity and lambda maxima of the styphnate ion are quite pH dependent; therefore, the pH is buffered to 6.8 to 7.0 with ammonium acetate. Under these conditions the molar absorptivity is 1.6 x 10/sup 4/ L/mol-cm. Analyses following the procedure in the Navy specification WS13444A using water were found to give low molar absorptivities (1.3 x 10/sup 4/ L/mol-cm) for the styphnic acid calibration resulting in erroneous values for barium styphnate purity.

  3. Kinetics of photoplasma of dense barium vapour

    NASA Astrophysics Data System (ADS)

    Kosarev, N. I.

    2015-03-01

    Barium vapour ionisation under laser photoexcitation of the resonance line at a wavelength of ? = 553.5 nm is studied numerically. Seed electrons, arising due to the associative ionisation of atoms, gain energy in superelastic collisions and lead to electron avalanche ionisation of the medium. The influence of radiative transfer in a cylindrical gas volume on the excitation kinetics of barium atoms, absorption dynamics of laser radiation and oscillation of ionisation-brightening wave under competition between ionising and quenching collisions of electrons with excited atoms is studied.

  4. Synthesis and characterization of iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of salicylidene-N-anilinoacetohydrazone (H2L1) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H2L2).

    PubMed

    AbouEl-Enein, S A; El-Saied, F A; Kasher, T I; El-Wardany, A H

    2007-07-01

    Salicylidene-N-anilinoacetohydrazone (H(2)L(1)) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H(2)L(2)) and their iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes have been synthesized and characterized by IR, electronic spectra, molar conductivities, magnetic susceptibilities and ESR. Mononuclear complexes are formed with molar ratios of 1:1, 1:2 and 1:3 (M:L). The IR studies reveal various modes of chelation. The electronic absorption spectra and magnetic susceptibility measurements show that the iron(III), nickel(II) and cobalt(II) complexes of H(2)L(1) have octahedral geometry. While the cobalt(II) complexes of H(2)L(2) were separated as tetrahedral structure. The copper(II) complexes have square planar stereochemistry. The ESR parameters of the copper(II) complexes at room temperature were calculated. The g values for copper(II) complexes proved that the Cu-O and Cu-N bonds are of high covalency. PMID:17113342

  5. Iron, copper, zinc, and manganese transport and regulation in pathogenic Enterobacteria: correlations between strains, site of infection and the relative importance of the different metal transport systems for virulence

    PubMed Central

    Porcheron, Gaëlle; Garénaux, Amélie; Proulx, Julie; Sabri, Mourad; Dozois, Charles M.

    2013-01-01

    For all microorganisms, acquisition of metal ions is essential for survival in the environment or in their infected host. Metal ions are required in many biological processes as components of metalloproteins and serve as cofactors or structural elements for enzymes. However, it is critical for bacteria to ensure that metal uptake and availability is in accordance with physiological needs, as an imbalance in bacterial metal homeostasis is deleterious. Indeed, host defense strategies against infection either consist of metal starvation by sequestration or toxicity by the highly concentrated release of metals. To overcome these host strategies, bacteria employ a variety of metal uptake and export systems and finely regulate metal homeostasis by numerous transcriptional regulators, allowing them to adapt to changing environmental conditions. As a consequence, iron, zinc, manganese, and copper uptake systems significantly contribute to the virulence of many pathogenic bacteria. However, during the course of our experiments on the role of iron and manganese transporters in extraintestinal Escherichia coli (ExPEC) virulence, we observed that depending on the strain tested, the importance of tested systems in virulence may be different. This could be due to the different set of systems present in these strains, but literature also suggests that as each pathogen must adapt to the particular microenvironment of its site of infection, the role of each acquisition system in virulence can differ from a particular strain to another. In this review, we present the systems involved in metal transport by Enterobacteria and the main regulators responsible for their controlled expression. We also discuss the relative role of these systems depending on the pathogen and the tissues they infect. PMID:24367764

  6. Effects of time, soil organic matter, and iron oxides on the relative retention and redistribution of lead, cadmium, and copper on soils.

    PubMed

    Diagboya, Paul N; Olu-Owolabi, Bamidele I; Adebowale, Kayode O

    2015-07-01

    In order to predict the bioavailability of toxic metals in soils undergoing degradation of organic matter (OM) and iron oxides (IOs), it is vital to understand the roles of these soil components in relation to metal retention and redistribution with time. In this present work, batch competitive sorptions of Pb(II), Cu(II), and Cd(II) were investigated between 1 and 90 days. Results showed that competition affected Cd(II) sorption more than Cu(II) and Pb(II). The sorption followed the trend Pb(II) >?>?Cu(II)?>?Cd(II), irrespective of aging, and this high preference for Pb(II) ions in soils reduced with time. Removal of OM led to reduction in distribution coefficient (K d) values of ?33 % for all cations within the first day. However, K d increased nearly 100 % after 7 days and over 1000 % after 90-day period. The enhanced K d values indicated that sorptions occurred on the long run on surfaces which were masked by OM. Removal of IO caused selective increases in the K d values, but this was dependent on the dominant soil constituent(s) in the absence of IO. The K d values of the IO-degraded samples nearly remained constant irrespective of aging indicating that sorptions on soil components other than the IO are nearly instantaneous while iron oxides played greater role than other constituents with time. Hence, in the soils studied, organic matter content determines the immediate relative metal retention while iron oxides determine the redistribution of metals with time. PMID:25721528

  7. Accumulation of copper and other metals by copper-resistant plant-pathogenic and saprophytic pseudomonads

    SciTech Connect

    Cooksey, D.A.; Azad, H.R. (Univ. of California, Riverside (United States))

    1992-01-01

    Copper-resistant strains of Pseudomonas syringae carrying the cop operon produce periplasmic copper-binding proteins, and this sequestration outside the cytoplasm has been proposed as a resistance mechanism. In this study, strain PS61 of P. syringae carrying the cloned cop operon accumulated more total cellular copper than without the operon. Several other copper-resistant pseudomonads with homology to cop were isolated from plants, and these bacteria also accumulated copper. Two highly resistant species accumulated up to 115 to 120 mg of copper per g (dry weight) of cells. P. putida 08891 was more resistant to several metals than P. syringae pv. tomato PT23, but this increased resistance was not correlated with an increased accumulation of metals other than copper. Several metals were accumulated by both PT23 and P. putida, but when copper was added to induce the cop operon, there was generally no increase of accumulation of the other metals, suggesting that the cop operon does not contribute to accumulation of these other metals. The exceptions were aluminium for PT23 and iron for P. putida, which accumulated to higher levels when copper was added to the cultures. The results of this study support the role of copper sequestration in the copper resistance mechanism of P. syringae and suggest that this mechanism is common to several copper-resistant Pseudomonas species found on plants to which antimicrobial copper compounds are applied for plant disease control.

  8. Theoretical interpretation for 2p - nd absorption spectra of iron, nickel, and copper in X-ray range measured at the LULI2000 facility

    NASA Astrophysics Data System (ADS)

    Poirier, M.; Arnault, P.; Bastiani-Ceccotti, S.; Blenski, T.; de Gaufridy de Dortan, F.; Gilleron, F.; Loisel, G.; Pain, J.-C.; Porcherot, Q.; Reverdin, C.; Silvert, V.; Thais, F.; Turck-Chièze, S.

    2013-11-01

    The 2p - nd absorption structures in medium Z elements present a valuable benchmark for atomic models since they exhibit a complex dependence on temperature and density. For these transitions lying in the X-ray range, one observes a competition between the spin-orbit splitting and the broadening associated to the excitation of complex structures. Detailed opacity codes based on the HULLAC or FAC suites agree with the statistical code SCO; but in iron computations predict higher peak absorption than measured. An addition procedure on opacities calculated with detailed codes is proposed and successfully tested.

  9. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell (Los Alamos, NM); Meek, Thomas T. (Knoxville, TN); Blake, Rodger D. (Santa Fe, NM)

    1990-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  10. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell (Los Alamos, NM); Meek, Thomas T. (Knoxville, TN); Blake, Rodger D. (Santa Fe, NM)

    1989-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  11. Highly aluminium doped barium and strontium ferrite nanoparticles prepared by citrate auto-combustion synthesis

    SciTech Connect

    Shirtcliffe, Neil J. [Nottingham Trent University, Clifton Lane, Clifton, Nottingham NG11 8NS (United Kingdom)]. E-mail: neil.shirtcliffe@ntu.ac.uk; Thompson, Simon [Nottingham Trent University, Clifton Lane, Clifton, Nottingham NG11 8NS (United Kingdom); O'Keefe, Eoin S. [QinetiQ, Farnborough, Hampshire (United Kingdom); Appleton, Steve [QinetiQ, Farnborough, Hampshire (United Kingdom); Perry, Carole C. [Nottingham Trent University, Clifton Lane, Clifton, Nottingham NG11 8NS (United Kingdom)]. E-mail: carole.perry@ntu.ac.uk

    2007-02-15

    Aluminium doped barium and strontium hexaferrite nanoparticles BaAl {sub x}Fe{sub (12-x)}O{sub 19} and SrAl {sub x}Fe{sub (12-x)}O{sub 19} were synthesised via a sol-gel route using citric acid to complex the ions followed by an auto-combustion reaction. This method shows promise for the synthesis of complex ferrite powders with small particle size. It was found that around half of the iron could be substituted for aluminium in the barium ferrite with structure retention, whereas strontium aluminium ferrites could be produced with any aluminium content including total substitution of the iron. All synthesised materials consisted of particles smaller than 1 {mu}m, which is the size of a single magnetic domain, and various doping levels were achieved with the final elemental composition being within the bounds of experimental error. The materials show structural and morphological changes as they move from iron to aluminium ferrites. Such materials may be promising for imaging applications.

  12. Recognition and prevention of barium enema complications.

    PubMed

    Williams, S M; Harned, R K

    1991-01-01

    The barium enema is a safe and accurate diagnostic study of the colon but, in rare cases, complications may result. Many of these can be prevented by proper equipment and careful attention to technique. When a complication does occur, prompt recognition and management is vital in decreasing morbidity and mortality. Perforation of the bowel is the most frequent serious complication, occurring in approximately 0.02% to 0.04% of patients. Rarely the colon may burst due to excessive transmural pressure alone. However, a colon weakened by iatrogenic trauma or disease is more likely to perforate during an enema than is a normal healthy bowel. Injury to the rectal mucosa or anal canal due to the enema tip or retention balloon is probably the most common traumatic cause of barium enema perforation. Inflation of a retention balloon within a stricture, neoplasm, inflamed rectum, or colostomy stoma is particularly hazardous. Recent deep biopsy or polypectomy with electrocautery makes the bowel more vulnerable to rupture. The tensile strength of the bowel wall is impaired in elderly patients, patients receiving long-term steroid therapy, and in disease states including neoplasm, diverticulitis, inflammatory bowel disease, and ischemia. Intraperitoneal perforation leads to a severe, acute peritonitis with intravascular volume depletion. The ensuing shock may be rapidly fatal. Prompt fluid replacement and laparotomy are essential. If the patient survives the initial shock and sepsis, later complications caused by dense intraperitoneal adhesions may develop. Extraperitoneal perforation is usually less catastrophic but may result in pain, sepsis, cellulitis, abscess, rectal stricture, or fistula. Intramural extravasation often forms a persistent submucosal barium granuloma which may ulcerate or be mistaken for a neoplasm. The most dramatic complication of barium enema is venous intravasation of barium. Fortunately, this is quite rare as it may be immediately lethal. Most cases have been attributed to trauma from the enema tip or retention balloon, mucosal inflammation, or misplacement of the tip in the vagina. Bacteremia has been found in as many as 23% of patients following barium enema and, in rare cases, may cause symptomatic septicemia. Other less common complications include barium impaction, water intoxication, allergic reactions, and cardiac arrhythmias. Preparatory laxatives and cleansing enemas have been implicated in some instances of dehydration, rectal trauma, water intoxication, and perforation. Careful review of the indications for examination, previous radiographs, and clinical history will identify many of the patients at greater risk for complications so that appropriate precautions may be observed.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1889235

  13. Method for preparing hydrous iron oxide gels and spherules

    DOEpatents

    Collins, Jack L.; Lauf, Robert J.; Anderson, Kimberly K.

    2003-07-29

    The present invention is directed to methods for preparing hydrous iron oxide spherules, hydrous iron oxide gels such as gel slabs, films, capillary and electrophoresis gels, iron monohydrogen phosphate spherules, hydrous iron oxide spherules having suspendable particles homogeneously embedded within to form composite sorbents and catalysts, iron monohydrogen phosphate spherules having suspendable particles of at least one different sorbent homogeneously embedded within to form a composite sorbent, iron oxide spherules having suspendable particles homogeneously embedded within to form a composite of hydrous iron oxide fiber materials, iron oxide fiber materials, hydrous iron oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, iron oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, dielectric spherules of barium, strontium, and lead ferrites and mixtures thereof, and composite catalytic spherules of barium or strontium ferrite embedded with oxides of Mg, Zn, Pb, Ce and mixtures thereof. These variations of hydrous iron oxide spherules and gel forms prepared by the gel-sphere, internal gelation process offer more useful forms of inorganic ion exchangers, catalysts, getters, dielectrics, and ceramics.

  14. Excess copper chelating therapy for Wilson disease induces anemia and liver dysfunction.

    PubMed

    Harada, Masaru; Miyagawa, Koichiro; Honma, Yuichi; Hiura, Masaaki; Shibata, Michihiko; Matsuhashi, Toru; Abe, Shintaro; Harada, Riko; Tabaru, Akinari

    2011-01-01

    A 37-year-old man was diagnosed with Wilson disease at the age of 14. His first manifestations were neurological. He was treated with trientine for more than 10 years and suffered from anemia and liver dysfunction. Wilson disease is a genetic disorder characterized by accumulation of copper in the body. Excess copper is toxic, but copper is an essential trace element. Copper-binding ceruloplasmin is important for iron metabolism. Excess copper chelating treatment-induced anemia and iron deposition in the liver was suspected. Proper monitoring of copper status is important for the management of Wilson disease. PMID:21757830

  15. Defects, Flux Pinning, and Changes of Copper Stoichiometry in Superconducting Yttrium Barium Copper Oxide

    Microsoft Academic Search

    Mark John Fendorf

    1992-01-01

    The purpose of this research is to understand the mechanism by which phase changes related to CuO plane (Cu-O chain layer) occupation initiate and propagate in superconducting YBaCuO. Phase changes of this type, where only the number of CuO layers in a unit cell changes, lead to a family of related crystal structures with stoichiometries Y_2Ba_4Cu _{rm 6 + x}O

  16. PIC1, an Ancient Permease in Arabidopsis Chloroplasts, Mediates Iron Transport

    Microsoft Academic Search

    Daniela Du; Anderson R. Med; Katrin Philippar

    In chloroplasts, the transition metals iron and copper play an essential role in photosynthetic electron transport and act as cofactors for superoxide dismutases. Iron is essential for chlorophyll biosynthesis, and ferritin clusters in plastids store iron during germination, development, and iron stress. Thus, plastidic homeostasis of transition metals, in particular of iron, is crucial for chloroplast as well as plant

  17. ARE THERE ANY STARS LACKING NEUTRON-CAPTURE ELEMENTS? EVIDENCE FROM STRONTIUM AND BARIUM

    SciTech Connect

    Roederer, Ian U., E-mail: iur@obs.carnegiescience.edu [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2013-01-01

    The cosmic dispersion in the abundances of the heavy elements strontium and barium in halo stars is well known. Strontium and barium are detected in most cool, metal-poor giants, but are these elements always detectable? To identify stars that could be considered probable candidates for lacking these elements, I examine the stellar abundance data available in the literature for 1148 field stars and 226 stars in dwarf galaxies, 776 of which have metallicities lower than [Fe/H] <-2.0. Strontium or barium have been detected in all field, globular cluster, and dwarf galaxy environments studied. All upper limits are consistent with the lowest detected ratios of [Sr/H] and [Ba/H]. The frequent appearance of these elements raises the intriguing prospect that at least one kind of neutron-capture reaction operates as often as the nucleosynthesis mechanisms that produce lighter elements, such as magnesium, calcium, or iron, although the yields of heavy elements may be more variable.

  18. Effects of operational parameters and common ions on the reduction of 2,4-dinitrotoluene by scrap copper-modified cast iron.

    PubMed

    Fan, Jin-Hong; Wang, Hong-Wu

    2015-07-01

    Scrap Cu-modified cast iron (CMCI) is a potent material for the reduction of 2,4-dinitrotoluene (2,4-DNT) by a surface-mediated reaction. However, the effects of operational parameters and common ions on its reduction and final rate are unknown. Results show that the 2,4-DNT reduction was significantly affected by Cu:Fe mass ratio and the optimum m(Cu:Fe) was 0.25 %. The slight pH-dependent trend of 2,4-DNT reduction by CMCI was observed at pH 3 to 11, and the maximum end product, 2,4-diaminotoluene (2,4-DAT), was generated at pH 7. Dissolved oxygen (DO) in the water reduced the 2,4-DNT degradation and the formation of 2,4-DAT. CMCI effectively treated high concentrations of 2,4-DNT (60 to 150 mg L(-1)). In addition, varying the concentration of (NH4)2SO4 from 0.001 to 0.1 mol L(-1) improved the efficiency of the reduction process. The green rust-like corrosion products (GR-SO4 (2-)) were also effective for 2,4-DNT reduction, in which Na2CO3 (0.01 to 0.2 mol L(-1)) significantly inhibited this reduction. The repeated-use efficiency of CMCI was also inhibited. Moreover, 2,4-DNT and its products, such as 4A2NT, 2A4NT, and 2,4-DAT, produced mass imbalance (<35 %). Hydrolysis of Fe(3+) and CO3 (2-) leading to the generation of Fe(OH)3 and conversion to FeOOH that precipitated on the surface and strongly adsorbed the products of reduction caused the inhibition of CO3 (2-). The 2,4-DNT reduction by CMCI could be described by pseudo-first-order kinetics. The operational conditions and common ions affected the 2,4-DNT reduction and its products by enhancing the corrosion of iron or accumulating a passive oxide film on the reactivity sites. PMID:25663339

  19. The Yeast Fre1p/Fre2p Cupric Reductases Facilitate Copper Uptake and Are Regulated by the Copper-modulated Mac1p Activator*

    E-print Network

    Alexandraki, Despina

    The Yeast Fre1p/Fre2p Cupric Reductases Facilitate Copper Uptake and Are Regulated by the Copper reductases which account for the total plasma membrane associated activity, a prerequisite for iron uptake, in Saccharomyces cerevi- siae. The two genes are transcriptionally induced by iron depletion. In this communication

  20. Establishment of a Protocol for Determining Gastrointestinal Transit Time in Mice Using Barium and Radiopaque Markers

    PubMed Central

    Myagmarjalbuu, Bolormaa; Moon, Myeong Ju; Heo, Suk Hee; Jeong, Seo In; Park, Jong-Seong; Jun, Jae Yeoul; Kang, Heoung Keun

    2013-01-01

    Objective The purpose of this study was to establish a minimally invasive and reproducible protocol for estimating the gastrointestinal (GI) transit time in mice using barium and radiopaque markers. Materials and Methods Twenty 5- to 6-week-old Balb/C female mice weighing 19-21 g were used. The animals were divided into three groups: two groups that received loperamide and a control group. The control group (n = 10) animals were administered physiological saline (1.5 mL/kg) orally. The loperamide group I (n = 10) and group II (n = 10) animals were administered 5 mg/kg and 10 mg/kg loperamide orally, respectively. Thirty minutes after receiving the saline or loperamide, the mice was administered 80 µL of barium solution and six iron balls (0.5 mm) via the mouth and the upper esophagus by gavage, respectively. Afterwards, the mice were continuously monitored with fluoroscopic imaging in order to evaluate the swallowing of the barium solution and markers. Serial fluoroscopic images were obtained at 5- or 10-min intervals until all markers had been excreted from the anal canal. For analysis, the GI transit times were subdivided into intestinal transit times (ITTs) and colon transit times (CTTs). Results The mean ITT was significantly longer in the loperamide groups than in the control group (p < 0.05). The mean ITT in loperamide group II (174.5 ± 32.3) was significantly longer than in loperamide group I (133.2 ± 24.2 minute) (p < 0.05). The mean CTT was significantly longer in loperamide group II than in the control group (p < 0.05). Also, no animal succumbed to death after the experimental procedure. Conclusion The protocol for our study using radiopaque markers and barium is reproducible and minimally invasive in determining the GI transit time of the mouse model. PMID:23323030

  1. Interactions in iron gall inks

    Microsoft Academic Search

    V. Jan?ovi?ová; M. ?eppan; B. Havlínová; M. Reháková; Z. Jakubíková

    2007-01-01

    Simple iron gall inks composed of gallic acid, ferrous sulfate, and gum arabic and in some cases also of copper(II) sulfate\\u000a were prepared. The process of iron ion complex formation with gallic acid was investigated using UV-VIS spectroscopy, pH measurements,\\u000a and by monitoring the concentration changes of Fe(II) ions. The admixture of Fe(II) ions to gallic acid induced a bathochromic

  2. Densities of liquid metals: calcium, strontium, barium

    Microsoft Academic Search

    S. Hiemstra; D. Prins; G. Gabrielse; J. B. Van Zytveld

    1977-01-01

    We report a method of measuring the densities of liquids at intermediate temperatures which employs Archimedes' Principle in a two-sinker arrangement. This method is then used to measure the densities of pure liquid calcium, strontium, and barium. We find ?(Ca) = 1.4931 ? 1.37 × 10 T(°C) from 850 ? 950°C, ?(Sr) = 2.5547 ? 2.83 × 10 T(°C) from

  3. PhotoElastic Effect in Barium Nitrate

    Microsoft Academic Search

    S. Bhagavantam; D. Suryanarayana

    1948-01-01

    DURING the course of our investigations on photo-elasticity, we have found that single crystals of barium nitrate behave in many respects in an exceptional manner. Differences between the stress-optical constants as determined by a Babinet compensator are (q11 - q12) = - 23.81 × 10-13, (q11 - q13) = - 18.06 × 10-13 and q44 = - 1.62 × 10-13

  4. Pathogenic adaptations to host-derived antibacterial copper

    PubMed Central

    Chaturvedi, Kaveri S.; Henderson, Jeffrey P.

    2014-01-01

    Recent findings suggest that both host and pathogen manipulate copper content in infected host niches during infections. In this review, we summarize recent developments that implicate copper resistance as an important determinant of bacterial fitness at the host-pathogen interface. An essential mammalian nutrient, copper cycles between copper (I) (Cu+) in its reduced form and copper (II) (Cu2+) in its oxidized form under physiologic conditions. Cu+ is significantly more bactericidal than Cu2+ due to its ability to freely penetrate bacterial membranes and inactivate intracellular iron-sulfur clusters. Copper ions can also catalyze reactive oxygen species (ROS) generation, which may further contribute to their toxicity. Transporters, chaperones, redox proteins, receptors and transcription factors and even siderophores affect copper accumulation and distribution in both pathogenic microbes and their human hosts. This review will briefly cover evidence for copper as a mammalian antibacterial effector, the possible reasons for this toxicity, and pathogenic resistance mechanisms directed against it. PMID:24551598

  5. Elaboration and characterization of barium silicate thin films.

    PubMed

    Genevès, T; Domenichini, B; Imhoff, L; Potin, V; Heintz, O; Peterlé, P M; Bourgeois, S

    2008-12-01

    Room temperature depositions of barium on a thermal silicon oxide layer were performed in ultra high vacuum (UHV). In-situ X-ray photoelectron spectroscopy (XPS) analyses were carried out as well after exposure to air as after subsequent annealings. These analyses were ex-situ completed by secondary ion mass spectrometry (SIMS) profiles and transmission electron microscopy (TEM) cross-sectional images. The results showed that after air exposure, the barium went carbonated. Annealing at sufficient temperature permitted to decompose the carbonate to benefit of a barium silicate. The silicate layer was formed by interdiffusion of barium with the initial SiO2 layer. PMID:18603436

  6. The role of barium esophagography in an endoscopy world.

    PubMed

    Katzka, David A

    2014-10-01

    Barium esophagography, although an old test, remains important to the understanding of esophageal physiology and diagnosis of esophageal disorders. It provides additive and/or confirmatory information to endoscopy and is the more accurate means of yielding diagnosis. Barium esophagography allows correlation of symptoms with barium findings and with varied textures substances. It allows, particularly for oropharyngeal dysfunction, implementation therapeutic maneuvers and instructions while testing. The caveat to maintaining the benefits of barium esophagography is continuing to promote and support expertise from our radiologists in performing these studies, which has been challenged by our cost-efficient and high-tech medical society. PMID:25216903

  7. The chemical composition of a mild barium star HD202109

    E-print Network

    Yushchenko, A V; Kim, C; Liang, Y; Musaev, F A; Galazutdinov, G A; Kim, Chulhee; Liang, Yanchun

    2003-01-01

    We present the result of chemical abundances of a mild barium star HD202109 (zeta Cyg) determined from the analysis of spectrum obtained by using a 2-m telescope at the Peak Terskol Observatory and a high-resolution spectrometer with R=80,000, signal to noise ratio >100. We also present the atmospheric parameters of the star determined by using various methods including iron-line abundance analysis. For line identifications, we use whole-range synthetic spectra computed by using the Kurucz database and the latest lists of spectral lines. Among the determined abundances of 51 elements, those of P, S, K, Cu, Zn, Ge, Rb, Sr, Nb, Mo, Ru, Rh, Pd, In, Sm, Gd, Tb, Dy, Er, Tm, Hf, Os, Ir, Pt, Tl, and Pb have not been previously known. Under the assumption that the overabundance pattern of Ba stars is due to wind-accretion process, adding information of more element abundances enables one to show that the heavy element overabundances of HD202109 can be explained with the wind accretion scenario model.

  8. Mechanisms of Copper Ion Mediated Huntington's Disease Progression

    Microsoft Academic Search

    Jonathan H. Fox; Jibrin A. Kama; Gregory Lieberman; Raman Chopra; Kate Dorsey; Vanita Chopra; Irene Volitakis; Robert A. Cherny; Ashley I. Bush; Steven Hersch; Katrina Gwinn-Hardy

    2007-01-01

    Huntington's disease (HD) is caused by a dominant polyglutamine expansion within the N-terminus of huntingtin protein and results in oxidative stress, energetic insufficiency and striatal degeneration. Copper and iron are increased in the striata of HD patients, but the role of these metals in HD pathogenesis is unknown. We found, using inductively-coupled-plasma mass spectroscopy, that elevations of copper and iron

  9. Green tea catechins as brain-permeable, non toxic iron chelators to “iron out iron” from the brain

    Microsoft Academic Search

    S. Mandel; O. Weinreb; L. Reznichenko; L. Kalfon; T. Amit

    Evidence to link abnormal metal (iron, copper and zinc) metabolism and handling with Parkinson’s and Alzheimer’s diseases\\u000a pathology has frequently been reported. The capacity of free iron to enhance and promote the generation of toxic reactive\\u000a oxygen radicals has been discussed numerous times. Metal chelation has the potential to prevent iron-induced oxidative stress\\u000a and aggregation of alpha-synuclein and beta-amyloid peptides.

  10. Effect of 3d-transition metal doping on the shielding behavior of barium borate glasses: a spectroscopic study.

    PubMed

    ElBatal, H A; Abdelghany, A M; Ghoneim, N A; ElBatal, F H

    2014-12-10

    UV-visible and FT infrared spectra were measured for prepared samples before and after gamma irradiation. Base undoped barium borate glass of the basic composition (BaO 40%-B2O3 60mol.%) reveals strong charge transfer UV absorption bands which are related to unavoidable trace iron impurities (Fe(3+)) within the chemical raw materials. 3d transition metal (TM)-doped glasses exhibit extra characteristic absorption bands due to each TM in its specific valence or coordinate state. The optical spectra show that TM ions favor generally the presence in the high valence or tetrahedral coordination state in barium borate host glass. Infrared absorption bands of all prepared glasses reveal the appearance of both triangular BO3 units and tetrahedral BO4 units within their characteristic vibrational modes and the TM-ions cause minor effects because of the low doping level introduced (0.2%). Gamma irradiation of the undoped barium borate glass increases the intensity of the UV absorption together with the generation of an induced broad visible band at about 580nm. These changes are correlated with suggested photochemical reactions of trace iron impurities together with the generation of positive hole center (BHC or OHC) within the visible region through generated electrons and positive holes during the irradiation process. PMID:24983922

  11. Intracellular Copper Does Not Catalyze the Formation of Oxidative DNA Damage in Escherichia coli?

    PubMed Central

    Macomber, Lee; Rensing, Christopher; Imlay, James A.

    2007-01-01

    Because copper catalyzes the conversion of H2O2 to hydroxyl radicals in vitro, it has been proposed that oxidative DNA damage may be an important component of copper toxicity. Elimination of the copper export genes, copA, cueO, and cusCFBA, rendered Escherichia coli sensitive to growth inhibition by copper and provided forcing circumstances in which this hypothesis could be tested. When the cells were grown in medium supplemented with copper, the intracellular copper content increased 20-fold. However, the copper-loaded mutants were actually less sensitive to killing by H2O2 than cells grown without copper supplementation. The kinetics of cell death showed that excessive intracellular copper eliminated iron-mediated oxidative killing without contributing a copper-mediated component. Measurements of mutagenesis and quantitative PCR analysis confirmed that copper decreased the rate at which H2O2 damaged DNA. Electron paramagnetic resonance (EPR) spin trapping showed that the copper-dependent H2O2 resistance was not caused by inhibition of the Fenton reaction, for copper-supplemented cells exhibited substantial hydroxyl radical formation. However, copper EPR spectroscopy suggested that the majority of H2O2-oxidizable copper is located in the periplasm; therefore, most of the copper-mediated hydroxyl radical formation occurs in this compartment and away from the DNA. Indeed, while E. coli responds to H2O2 stress by inducing iron sequestration proteins, H2O2-stressed cells do not induce proteins that control copper levels. These observations do not explain how copper suppresses iron-mediated damage. However, it is clear that copper does not catalyze significant oxidative DNA damage in vivo; therefore, copper toxicity must occur by a different mechanism. PMID:17189367

  12. Analytical use of the selective extraction of copper as its phenylacetate.

    PubMed

    Adam, J; Pribil, R

    1972-10-01

    Chloroform solution of phenylacetic add has been found very suitable for extraction and colorimetric determination of copper. Iron and uranium are the main interferences, which can be overcome by masking with ammonium fluoridc. Under these conditions, only gold(III), platinum(IV) and palladium(II) are co-extracted, but their colour does not interfere with measurement of the green copper extract at 700 nm. The method has been applied to the determination of copper in iron, steels, uranium, lead concentrates and alloys containing nickel, cobalt, etc. The extraction procedure can also be used to remove interference of iron, copper and uranium in the determination of manganese with formaldoxime. PMID:18961161

  13. Inhibition of copper uptake in yeast reveals the copper transporter Ctr1p as a potential molecular target of saxitoxin.

    PubMed

    Cusick, Kathleen D; Minkin, Steven C; Dodani, Sheel C; Chang, Christopher J; Wilhelm, Steven W; Sayler, Gary S

    2012-03-01

    Saxitoxin is a secondary metabolite produced by several species of dinoflagellates and cyanobacteria which targets voltage-gated sodium and potassium channels in higher vertebrates. However, its molecular target in planktonic aquatic community members that co-occur with the toxin producers remains unknown. Previous microarray analysis with yeast identified copper and iron-homeostasis genes as being differentially regulated in response to saxitoxin. This study sought to identify the molecular target in microbial cells by comparing the transcriptional profiles of key copper and iron homeostasis genes (CTR1, FRE1, FET3, CUP1, CRS5) in cells exposed to saxitoxin, excess copper, excess iron, an extracellular Cu(I) chelator, or an intracellular Cu(I) chelator. Protein expression and localization of Ctr1p (copper transporter), Fet3p (multicopper oxidase involved in high-affinity iron uptake), and Aft1p (iron regulator) were also compared among treatments. Combined transcript and protein profiles suggested saxitoxin inhibited copper uptake. This hypothesis was confirmed by intracellular Cu(I) imaging with a selective fluorescent probe for labile copper. On the basis of the combined molecular and physiological results, a model is presented in which the copper transporter Ctr1p serves as a molecular target of saxitoxin and these observations are couched in the context of the eco-evolutionary role this toxin may serve for species that produce it. PMID:22304436

  14. A Novel Copper A Containing Menaquinol NO Reductase from Bacillus azotoformans

    E-print Network

    Schroeder, Imke

    A Novel Copper A Containing Menaquinol NO Reductase from Bacillus azotoformans Suharti, Marc J. F of one non-heme iron, two copper atoms and of two b-type hemes per enzyme complex. Heme c was absent features of this enzyme that distinguish it from other NO reductases. First, the enzyme contains copper

  15. The effect of zinc methionine or copper lysine on stocker calves grazing oat pastures 

    E-print Network

    Griffeth, Laura Ann

    1993-01-01

    for growth and the prevention of anemia in rats since 1928 (Hart et al. , 1928). Many 12 experiments soon followed providing evidence of copper's essentiality for growth and prevention of a wide range of clinical and pathological disorders in many... in swine when 250 ppm copper as copper sulfate was added. The high level of copper can lead to anemia, copper toxicity, or zinc deficiency unless the diets contain adequate iron and zinc as antagonists. One hundred and fifty ppm of both iron and zinc can...

  16. Accumulation and hyperaccumulation of copper in plants

    NASA Astrophysics Data System (ADS)

    Adam, V.; Trnkova, L.; Huska, D.; Babula, P.; Kizek, R.

    2009-04-01

    Copper is natural component of our environment. Flow of copper(II) ions in the environment depends on solubility of compounds containing this metal. Mobile ion coming from soil and rocks due to volcanic activity, rains and others are then distributed to water. Bio-availability of copper is substantially lower than its concentration in the aquatic environment. Copper present in the water reacts with other compounds and creates a complex, not available for organisms. The availability of copper varies depending on the environment, but moving around within the range from 5 to 25 % of total copper. Thus copper is stored in the sediments and the rest is transported to the seas and oceans. It is common knowledge that copper is essential element for most living organisms. For this reason this element is actively accumulated in the tissues. The total quantity of copper in soil ranges from 2 to 250 mg / kg, the average concentration is 30 mg / kg. Certain activities related to agriculture (the use of fungicides), possibly with the metallurgical industry and mining, tend to increase the total quantity of copper in the soil. This amount of copper in the soil is a problem particularly for agricultural production of food. The lack of copper causes a decrease in revenue and reduction in quality of production. In Europe, shows the low level of copper in total 18 million hectares of farmland. To remedy this adverse situation is the increasing use of copper fertilizers in agricultural soils. It is known that copper compounds are used in plant protection against various illnesses and pests. Mining of minerals is for the development of human society a key economic activity. An important site where the copper is mined in the Slovakia is nearby Smolníka. Due to long time mining in his area (more than 700 years) there are places with extremely high concentrations of various metals including copper. Besides copper, there are also detected iron, zinc and arsenic. Various plant species have adapted on such stress. The aim of this study is to investigate the behaviour of copper in plants and to assess its potential effect on the surrounding environment. To detect copper in biological samples electrochemical methods were employed particularly differential pulse voltammetry (DPV). Copper gave signals at 0.02 V measured by DPV. The obtained calibration dependence was linear (R2 = 0.995). Further, this method was utilized for determination of copper in real soil samples obtained from previously mentioned heavy-metal-polluted mining area. The content varied within range from tens to hundreds of mg of copper per kg of the soil. Moreover, we focused on investigation of copper influence on seedlings of Norway spruce. The seedlings were treated with copper (0, 0.1, 10 and 100 mM) for four weeks. We observed anatomical-morphological changes and other biochemical parameters in plants. We determined that seedlings synthesized more than 48 % protective thiols (glutathione and phytochelatins) compared to control ones. We investigated copper distribution in plant tissues by diphenylcarbazide staining. We found out that copper is highly accumulated in parenchymal stalk cells. In needles, change in auto-fluorescence of parenchymal cells of mesoderm similarly to endodermis cells. Besides, we analyzed samples of plants from the polluted area (spruce, pin, birch). The data obtained well correlated with previously mentioned. Acknowledgement The work on this experiment was supported by grant: INCHEMBIOL MSM0021622412.

  17. Laboratory and prediction of barium sulfate scaling at high-barium formation water

    Microsoft Academic Search

    Amer Badr BinMerdhah; Abu Azam Mohd Yassin; Mazen Ahmed Muherei

    2010-01-01

    Scale formation in surface and subsurface oil and gas production equipment has been recognized to be a major operational problem. It has been also recognized as major causes of formation damage either in injection or producing wells. This study was conducted to investigate the permeability reduction caused by deposition of barium sulfate in sandstone cores from mixing of injected seawater

  18. Excessive barium and radium 226 in Illinois drinking water

    Microsoft Academic Search

    Calabrese

    1977-01-01

    The Illinois EPA has found 16 cities with drinking water containing barium concentrations exceeding the current state and federal drinking water standard of 1 mg\\/l. In addition, the presence of varying amounts of alpha activity reveal traces of radium-226 in many Illinois water wells. Increased levels of radium and barium are concurrent with a rise in cancer rates in the

  19. PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE

    E-print Network

    Malovichko, Galina

    PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE G.MALOVICHKO, V calcium titanate crystals, Ba0.77Ca0.23TiO3, in the temperature range between 4.2 K and 300 K are reported of crystals from barium titanate (BT) family make them promising candidates for various applications

  20. Role of corrosion inhibiting pigments on the electrochemical kinetics of a copper-containing aluminum alloy

    SciTech Connect

    Kendig, M.; Cunningham, M.; Jeanjaquet, S.; Hardwick, D. [Rockwell Science Center, Thousand Oaks, CA (United States)

    1997-11-01

    The electrochemical polarization behavior of the copper-containing Al 2024-T3 alloy in deaerated 0.01 M NaCl saturated with a number of solid inhibitors demonstrates that one of the compounds examined, barium metaborate, exhibits an inhibiting power in excess of that of zinc chromate. Electrochemical polarization of a synthetic {theta}-phase CuAl{sub 2} intermetallic in aerated 0.01 M NaCl with and without the presence of the barium metaborate and zinc chromate inhibitors has also been examined.

  1. Barium Enhancement in NGC 6819 Blue Stragglers

    NASA Astrophysics Data System (ADS)

    Milliman, Katelyn; Mathieu, Robert D.; Schuler, Simon C.

    2015-01-01

    Possible formation pathways for blue straggler stars include mergers in hierarchical triple systems, stellar collisions during dynamical encounters, and mass transfer from a giant companion. Extensive work on the blue stragglers in the old open cluster NGC 188 (7 Gyr) has led to exciting discoveries including a binary secondary mass distribution peaked at 0.5 MSolar and the detection of three young white dwarf binary companions. These indicate that mass transfer from an asymptotic giant branch star is the dominant mechanism for blue straggler formation in open clusters. Such mass transfer events should pollute the surface abundance of the blue straggler with nucleosynthesis products from the evolved donor. The other formation pathways, mergers and collisions, are predicted to produce no such enhancements. In an effort to move beyond NGC 188 and into other open clusters we present the first results of a surface abundance study of the blue stragglers in the intermediate-aged open cluster NGC 6819 (2.5 Gyr) using the Hydra multi-object spectrograph on the WIYN 3.5 m telescope. This part of our study centers on the s-process element barium as a tracer of formation via mass transfer. We compare the blue straggler surface abundance of barium to that of a sample of main-sequence stars in NGC 6819 and find multiple blue stragglers with anomalous abundances. Surprising, most of the blue stragglers with barium anomalies show no radial-velocity evidence for a companion. We gratefully acknowledge funding from the National Science Foundation under grant AST- 0908082 and the Wisconsin Space Grant Consortium.

  2. Scattering lengths of calcium and barium isotopes

    E-print Network

    U. Dammalapati; L. Willmann; S. Knoop

    2011-10-25

    We have calculated the s-wave scattering length of all the even isotopes of calcium (Ca) and barium (Ba), in order to investigate the prospect of Bose-Einstein condensation (BEC). For Ca we have used an accurate molecular potential based on detailed spectroscopic data. Our calculations show that Ca does not provide other isotopes alternative to the recently Bose condensed 40Ca that suffers strong losses because of a very large scattering length. For Ba we show by using a model potential that the even isotopes cover a broad range of scattering lengths, opening the possibility of BEC for at least one of the isotopes.

  3. Scattering lengths of calcium and barium isotopes

    E-print Network

    Dammalapati, U; Knoop, S

    2011-01-01

    We have calculated the s-wave scattering length of all the even isotopes of calcium (Ca) and barium (Ba), in order to investigate the prospect of Bose-Einstein condensation (BEC). For Ca we have used an accurate molecular potential based on detailed spectroscopic data. Our calculations show that Ca does not provide other isotopes alternative to the recently Bose condensed 40Ca that suffers strong losses because of a very large scattering length. For Ba we show by using a model potential that the even isotopes cover a broad range of scattering lengths, opening the possibility of BEC for at least one of the isotopes.

  4. Short-cavity squeezing in barium

    NASA Technical Reports Server (NTRS)

    Hope, D. M.; Bachor, H-A.; Manson, P. J.; Mcclelland, D. E.

    1992-01-01

    Broadband phase sensitive noise and squeezing were experimentally observed in a system of barium atoms interacting with a single mode of a short optical cavity. Squeezing of 13 +/- 3 percent was observed. A maximum possible squeezing of 45 +/- 8 percent could be inferred for out experimental conditions, after correction for measured loss factors. Noise reductions below the quantum limit were found over a range of detection frequencies 60-170 MHz and were best for high cavity transmission and large optical depths. The amount of squeezing observed is consistent with theoretical predictions from a full quantum statistical model of the system.

  5. Copper Cleanup

    NSDL National Science Digital Library

    2013-12-05

    In this hands-on experiment, kids use chemistry to explore whether acids or bases are better at restoring a penny’s shine. Kids follow the scientific process to test a common household cleaning products alongside ketchup, cola, and other kitchen staples, and may be surprised by the results! A downloadable data sheet is available on the Copper Cleanup activity resources page.

  6. Effects of methionine chelate- or yeast proteinate-based supplement of copper, iron, manganese and zinc on broiler growth performance, their distribution in the tibia and excretion into the environment.

    PubMed

    Singh, Abhay Kumar; Ghosh, Tapan Kumar; Haldar, Sudipto

    2015-04-01

    A straight-run flock of 1-day-old Cobb 400 chicks (n?=?432) was distributed into four treatment groups (9 replicate pens in each group, 12 birds in a pen) for a 38-day feeding trial evaluating the effects of a methionine chelate (Met-TM)- or a yeast proteinate (Yeast-TM)-based supplement of copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) on growth performance, bone criteria and some metabolic indices in commercial broiler chickens. The diets were either not supplemented with any trace elements at all (negative control, NC) or supplemented with an inorganic (sulphate) trace element premix (inorganic TM (ITM), 1 g/kg feed), the Met-TM (1 g/kg feed) and the Yeast-TM (0.5 g/kg feed). Body weight, feed conversion ratio and dressed meat yield at 38 days were better in the Yeast-TM-supplemented group as compared with the NC, ITM and Met-TM groups (p?

  7. Processing of yttrium-doped barium zirconate for high proton conductivity

    E-print Network

    Processing of yttrium-doped barium zirconate for high proton conductivity Peter Babilo Materials the transport properties of yttrium-doped barium zirconate (BYZ) have been explored, with the aim of attaining. INTRODUCTION Doped perovskites, such as barium cerate (BaCeO3), strontium cerate (SrCeO3), and barium zirconate

  8. Role for copper in the cellular and regulatory effects of heme-hemopexin

    Microsoft Academic Search

    Ann Smith; Kimberly R. Rish; Rachel Lovelace; Jennifer F. Hackney; Rachel M. Helston

    2009-01-01

    Hemopexin (HPX) binds heme tightly, thus protecting cells from heme toxicity during hemolysis, trauma and ischemia-reperfusion\\u000a injury. Heme uptake via endocytosis of heme-HPX followed by heme catabolism by heme oxygenase-1 (HMOX1) raises regulatory\\u000a iron pools, thus linking heme metabolism with that of iron. Normal iron homeostasis requires copper-replete cells. When heme-HPX\\u000a induces HMOX1, the copper-storing metallothioneins (MTs) are also induced

  9. Investigation of Conventional- and Induction-Sintered Iron and Iron-Based Powder Metal Compacts

    NASA Astrophysics Data System (ADS)

    Çavdar, U?ur; Atik, Enver

    2014-06-01

    Induction sintering was developed as an alternative method to conventional sintering to sinter iron-based powder metal (PM) compacts. Several compositions of compact such as pure iron, 3 wt.% copper mixed iron, or 3 wt.% bronze mixed iron were sintered by using induction sintering machines with 12 kW power and 30 kHz frequency. The mechanical properties, microstructural properties, densities, and microhardness values were investigated for both processes. Iron-based PM compacts sintered at 1120°C by induction in 8.33 min (500 s) were found to be similar to those sintered conventionally in 30 min. The results were compared with the experimental studies.

  10. Simultaneous determination of arsenic, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in fertilizers by microwave acid digestion and inductively coupled plasma-optical emission spectrometry detection: single-laboratory validation of a modification and extension of AOAC 2006.03.

    PubMed

    Webb, Sharon; Bartos, James; Boles, Rhonda; Hasty, Elaine; Thuotte, Ethel; Thiex, Nancy J

    2014-01-01

    A single-laboratory validation study was conducted for the simultaneous determination of arsenic, cadmium, calcium, cobalt, copper, chromium, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in all major types of commercial fertilizer products by microwave digestion and inductively coupled plasma-optical emission spectroscopy analysis. This validation study proposes an extension and modification of AOAC 2006.03. The extension is the inclusion of calcium, copper, iron, magnesium, manganese, and zinc, and the modification is incorporation of hydrochloric acid in the digestion system. This dual acid digestion utilizes both hydrochloric and nitric acids in a 3 to 9 mL volume ratio/100 mL. In addition to 15 of the 30 original validation materials used in the 2006.03 collaborative study, National Institute of Standards and Technology Standard Reference Material 695 and Magruder 2009-06 were incorporated as accuracy materials. The main benefits of this proposed method are a significant increase in laboratory efficiency when compared to the use of both AOAC Methods 965.09 and 2006.03 to achieve the same objective and an enhanced recovery of several metals. PMID:25051614

  11. Do all barium stars have a white dwarf companion?

    NASA Technical Reports Server (NTRS)

    Dominy, J. F.; Lambert, D. L.

    1983-01-01

    International Ultraviolet Explorer short-wavelength, low-dispersion spectra were analyzed for four barium, two mild barium, and one R-type carbon star in order to test the hypothesis that the barium and related giants are produced by mass transfer from a companion now present as a white dwarf. An earlier tentative identification of a white dwarf companion to the mild barium star Zeta Cyg is confirmed. For the other stars, no ultraviolet excess attributable to a white dwarf is seen. Limits are set on the bolometric magnitude and age of a possible white dwarf companion. Since the barium stars do not have obvious progenitors among main-sequence and subgiant stars, mass transfer must be presumed to occur when the mass-gaining star is already on the giant branch. This restriction, and the white dwarf's minimum age, which is greater than 8 x 10 to the 8th yr, determined for several stars, effectively eliminates the hypothesis that mass transfer from an asymptotic giant branch star creates a barium star. Speculations are presented on alternative methods of producing a barium star in a binary system.

  12. Dispersion strengthened copper

    DOEpatents

    Sheinberg, H.; Meek, T.T.; Blake, R.D.

    1990-01-09

    A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.

  13. The influence of copper on Zircaloy spent fuel cladding degradation under a potential tuff repository condition

    SciTech Connect

    Smith, H.D.

    1987-03-01

    This paper reports the results of an experiment designed to detect the influence of copper on Zircaloy spent fuel cladding degradation in one possible repository environment. Copper and copper alloys are being considered for use in a tuff repository. The compatibility of a copper waste package container and the Zircaloy cladding on spent fuel has been questioned essentially because copper ion has been observed to accelerate zirconium alloy corrosion in acid environments, as does ferric iron, and a phenomenon called "crud-induced localized corrosion" is observed in some Boiling Water Reactors where thorugh-the-wall corrosion pits develop beneath copper-rich crud deposits. 16 refs., 6 figs., 2 tabs.

  14. Microstructure and magnetism in barium strontium titanate (BSTO)-barium hexaferrite (BaM) multilayers

    SciTech Connect

    Frey, N.A. [Materials Physics Laboratory, Physics Department, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Heindl, R. [Materials Physics Laboratory, Physics Department, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Srinath, S. [Materials Physics Laboratory, Physics Department, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Srikanth, H. [Materials Physics Laboratory, Physics Department, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States)]. E-mail: sharihar@cas.usf.edu; Dudney, N.J. [Solid State Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2005-08-11

    High quality multilayers of barium ferrite (BaM) and barium strontium titanate (BSTO) were grown in optimized conditions on thermally oxidized Si(1 0 0) and Al{sub 2}O{sub 3} substrates using magnetron sputtering. As-grown films were amorphous and different annealing procedures were explored to stabilize crystalline phases. BSTO and BaM phases were identified using X-ray diffraction and cross-sectional scanning electron micrographs showed sharp interfaces between BSTO and BaM layers. Magnetic hysteresis loops obtained at various temperatures and field orientations showed a large coercivity ({approx}2500 Oe) consistent with the hard magnetic hexaferrite component. Hysteresis loops also revealed the distinct influence of magnetocrystalline and shape anisotropies at different temperature ranges.

  15. A high-altitude barium radial injection experiment

    NASA Technical Reports Server (NTRS)

    Wescott, E. M.; Stenbaek-Nielsen, H. C.; Hallinan, T. J.; Deehr, C. S.; Romick, G. J.; Olson, J. V.; Roederer, J. G.; Sydora, R.

    1980-01-01

    A rocket launched from Poker Flat, Alaska, carried a new type of high-explosive barium shaped charge to 571 km, where detonation injected a thin disk of barium vapor with high velocity nearly perpendicular to the magnetic field. The TV images of the injection are spectacular, revealing three major regimes of expanding plasma which showed early instabilities in the neutral gas. The most unusual effect of the injection is a peculiar rayed barium-ion structure lying in the injection plane and centered on a 5 km 'black hole' surrounding the injection point. Preliminary electrostatic computer simulations show a similar rayed development.

  16. Designed microstructures in textured barium hexaferrite

    NASA Astrophysics Data System (ADS)

    Hovis, David Brian

    It is a fundamental principle of materials science that the microstructure of a material defines its properties and ultimately its performance for a given application. A prime example of this can be found in the large conch shell Strombus gigas, which has an intricate microstructure extending across five distinct length scales. This microstructure gives extraordinary damage tolerance to the shell. The structure of Strombus gigas cannot be replicated in a modern engineering ceramic with any existing processing technique, so new processing techniques must be developed to apply this structure to a model material. Barium hexaferrite was chosen as a model material to create microstructures reminiscent of Strombus gigas and evaluate its structure-property relations. This work describes novel processing methods to produce textured barium hexaferrite with no coupling between the sample geometry and the texture direction. This technique, combining magnetic field-assisted gelcasting with templated grain growth, also allows multilayer samples to be fabricated with different texture directions in adjacent layers. The effects of adding either B2O3 or excess BaCO 3 on the densification and grain growth of barium hexaferrite was studied. The texture produced using this technique was assessed using orientation imaging microscopy (OIM) at Oak Ridge National Laboratory. These measurements showed peak textures as high as 60 MRD and sharp interfaces between layers cast with different texture directions. The effect of oxygen on the quality of gelcasting is also discussed, and it is shown that with proper mold design, it is possible to gelcast multiple layers with differing texture directions without delamination. Monolithic and multilayer samples were produced and tested in four point bending to measure the strength and work of fracture. Modulus measurements, made with the ultrasonic pulse-echo technique, show clear signs of microcracking in both the isotropic and textured samples. Both the strength and work of fracture were shown to be affected by the texture direction. The multilayer samples did not show significant improvements in either strength or work of fracture, but they did show much less variability than the monolithic samples.

  17. Copper Extraction Demonstration

    NSDL National Science Digital Library

    Summary This demonstration uses sulfuric acid and crushed copper ore (malachite) to produce a solution of copper sulfate and carbonic acid in a beaker. When a freshly sanded nail is dropped into the copper sulfate ...

  18. Ion beam synthesis and investigation of nanocomposite multiferroics based on barium titanate with 3 d metal nanoparticles

    NASA Astrophysics Data System (ADS)

    Khalitov, N. I.; Lyadov, N. M.; Valeev, V. F.; Khaibullin, R. I.; Faizrakhmanov, I. A.; Dulov, E. N.; Tagirov, L. R.; Ibragimov, Sh. Z.; Prikhodko, K. E.; Roddatis, V. V.; Maksutoglu, M.; Kazan, S.; Mikailzade, F. A.

    2013-06-01

    Samples of nanocomposite multiferroics have been synthesized by implantation of Co+, Fe+, and Ni+ ions with an energy of 40 keV into ferroelectric barium titanate plates to doses in the range (0.5-1.5) × 1017 ions/cm2. It has been found that nanoparticles of metallic iron, cobalt, or nickel are formed in the barium titanate layer subjected to ion bombardment. With an increase in the implantation dose, the implanted samples sequentially exhibit superparamagnetic, soft magnetic, and, finally, strong ferromagnetic properties at room temperature. The average sizes of ion-synthesized 3 d-metal nanoparticles vary in the range from 5 to 10 nm depending on the implantation dose. Investigation of the orientation dependence of the magnetic hysteresis loops has demonstrated that the samples show a uniaxial ("easy plane") magnetic anisotropy typical of thin granular magnetic films. Ferromagnetic BaTiO3: 3 d metal samples are characterized by a significant shift of the ferromagnetic resonance signal in an external electric field, as well as by a large (in magnitude) magnetodielectric effect at room temperature. These results indicate that there is a strong magnetoelectric coupling between the ferroelectric barium titanate matrix and ion-synthesized nanoparticles of magnetic metals.

  19. Phased surgical treatment of barium enema-induced rectal injury and retention of barium in the pelvic floor space

    PubMed Central

    Yang, Xuefei; Xia, Ligang; Huang, Jun; Wang, Jianping

    2014-01-01

    Iatrogenic injuries caused by barium enema are rarely reported. Following a phased surgical protocol for up to one year, we have successfully treated a patient with rectal injury and severe infection of the pelvic floor space complicated with retention of large amounts of barium and vaginal fistula. In this article, the phased surgery planning for the treatment of rectal injury complicated with vaginal fistula is discussed in terms of the pros and cons, and the observed effect and evolution of barium retained in the pelvic floor space are described. PMID:25405155

  20. Magnetic properties of substituted barium ferrite powders

    SciTech Connect

    Gruskova, A. [Slovak Univ. of Technology, Bratislava (Slovakia). Dept. of Electrotechnology] [Slovak Univ. of Technology, Bratislava (Slovakia). Dept. of Electrotechnology

    1994-03-01

    Hexagonal barium ferrites were prepared using the citrate method. Cobalt and titanium were added in the amounts x from 0.2 to 1.1 ion/f.u. related to the formula BaCo{sub x}Ti{sub x}Fe{sub 12{minus}2x}O{sub 19}. The heat treatment has been applied in three steps of 550 C/5 hrs, 850 C/2 hrs and 1,100 C/2 hrs. The following magnetic properties have been achieved: H{sub c} {approximately} 80 kA/m, J{sub s} {approximately} 120 {times} 10{sup {minus}6} Tkg{sup {minus}1} m{sup 3}, and J{sub r} {approximately} 60 {times} 10{sup {minus}6} Tkg{sup {minus}1} m{sup 3} in the composition for which x is equal to 0.5 ion/f.u. The magnetic parameters have been measured by the vibration magnetometer.

  1. The many "faces" of copper in medicine and treatment.

    PubMed

    Hordyjewska, Anna; Popio?ek, ?ukasz; Kocot, Joanna

    2014-08-01

    Copper (Cu) is an essential microelement found in all living organisms with the unique ability to adopt two different redox states-in the oxidized (Cu(2+)) and reduced (Cu(+)). It is required for survival and serves as an important catalytic cofactor in redox chemistry for proteins that carry out fundamental biological functions, important in growth and development. The deficit of copper can result in impaired energy production, abnormal glucose and cholesterol metabolism, increased oxidative damage, increased tissue iron (Fe) accrual, altered structure and function of circulating blood and immune cells, abnormal neuropeptides synthesis and processing, aberrant cardiac electrophysiology, impaired myocardial contractility, and persistent effects on the neurobehavioral and the immune system. Increased copper level has been found in several disorders like e.g.: Wilson's disease or Menke's disease. New findings with the great potential for impact in medicine include the use of copper-lowering therapy for antiangiogenesis, antifibrotic and anti-inflammatory purposes. The role of copper in formation of amyloid plaques in Alzheimer's disease, and successful treatment of this disorder in rodent model by copper chelating are also of interest. In this work we will try to describe essential aspects of copper in chosen diseases. We will represent the evidence available on adverse effect derived from copper deficiency and copper excess. We will try to review also the copper biomarkers (chosen enzymes) that help reflect the level of copper in the body. PMID:24748564

  2. Study of the photovoltaic effect in thin film barium titanate

    NASA Technical Reports Server (NTRS)

    Grannemann, W. W.; Dharmadhikari, V. S.

    1983-01-01

    The feasibility of making non-volatile digital memory devices of barium titanate, BaTiO3, that are integrated onto a silicon substrate with the required ferroelectric film produced by processing, compatible with silicon technology was examined.

  3. Calculated emission rates for barium releases in space

    NASA Technical Reports Server (NTRS)

    Stenbaek-Nielsen, H. C.

    1989-01-01

    The optical emissions from barium releases in space are caused by resonance and fluorescent scattering of sunlight. Emission rates for the dominant ion and neutral lines are calculated assuming the release to be optically thin and the barium to be in radiative equilibrium with the solar radiation. The solar spectrum has deep Fraunhofer absorption lines at the primary barium ion resonances. A velocity component toward or away from the sun will Doppler shift the emission lines relative to the absorption lines and the emission rates will increase many-fold over the rest value. The Doppler brightening is important in shaped charge or satellite releases where the barium is injected at high velocities. Emission rates as a function of velocity are calculated for the 4554, 4934, 5854, 6142 and 6497 A ion emission lines and the dominant neutral line at 5535 A. Results are presented for injection parallel to the ambient magnetic field, B, and for injection at an angle to B.

  4. Upper gastrointestinal barium evaluation of duodenal pathology: A pictorial review

    PubMed Central

    Gupta, Pankaj; Debi, Uma; Sinha, Saroj Kant; Prasad, Kaushal Kishor

    2014-01-01

    Like other parts of the gastrointestinal tract (GIT), duodenum is subject to a variety of lesions both congenital and acquired. However, unlike other parts of the GIT viz. esophagus, rest of the small intestine and large intestine, barium evaluation of duodenal lesions is technically more challenging and hence not frequently reported. With significant advances in computed tomography technology, a thorough evaluation including intraluminal, mural and extramural is feasible in a single non-invasive examination. Notwithstanding, barium evaluation still remains the initial and sometimes the only imaging study in several parts of the world. Hence, a thorough acquaintance with the morphology of various duodenal lesions on upper gastrointestinal barium examination is essential in guiding further evaluation. We reviewed our experience with various common and uncommon barium findings in duodenal abnormalities. PMID:25170399

  5. Molecular Structure of Copper

    NSDL National Science Digital Library

    2003-04-10

    Man has known of copper since antiquity. Copper is known for its unique reddish hue, its good electrical and thermal conductivity, and widespread abundance. It is malleable and extremely ductile. Copper melts at 1357 degrees kelvin and boils at 2840 degrees kelvin. Copper crystals are commonly found in cubic and dodecahedral forms. Copper is widely used in wiring and electronics. Two important alloys of copper are brass and bronze. Also, all American coins are now made of copper alloys. Humans require trace amounts of copper; larger doses result in poisoning.

  6. Induction of siderophore activity in Anabaena spp. and its moderation of copper toxicity.

    PubMed Central

    Clarke, S E; Stuart, J; Sanders-Loehr, J

    1987-01-01

    Growth of Anabaena sp. strain 7120 (in the absence of chelators or added iron) was inhibited by the addition of 2.1 to 6.5 microM copper and was abolished by copper concentration of 10 microM or higher. When the copper was chelated to schizokinen (the siderophore produced by this organism in response to iron starvation), the toxic effects were eliminated. Analysis of culture filtrates showed that the cupric schizokinen remains in the medium, thereby lowering the amount of copper taken up by the cells. Although this organism actively transports ferric schizokinen, it apparently does not recognize the cupric complex. Thus, Anabaena sp. is protected from copper toxicity under conditions in which siderophore is being produced. For cells grown in low iron, the accumulation of extracellular schizokinen was observed to parallel cell growth and continue well into stationary phase. The actual iron status of the organism was monitored by using iron uptake velocity as an assay. Cultures grown on 0.1 microM added iron were found to be severely iron limited upon reaching stationary phase, thus explaining the continued production of schizokinen. These data show that the siderophore system in Anabaena spp. has developed primarily as a response to iron starvation and that additional functions such as alleviation of copper toxicity or allelopathic inhibition of other algal species are merely secondary benefits. PMID:2955743

  7. Prompt ionization in the CRIT II barium releases

    Microsoft Academic Search

    R. B. Torbert; C. A. Kletzing; K. Liou; D. Rau

    1992-01-01

    Observations of electron and ion distributions inside a fast neutral barium jet in the ionosphere show significant fluxes within 4 km of release, presumably related to beam plasma instability processes involved in the Critical Ionization Velocity (CIV) effect. Electron fluxes exceeding 5 x 10 exp 12\\/sq cm-str-sec-keV were responsible for ionizing both the streaming barium and ambient oxygen. Resulting ion

  8. Elaboration and characterization of doped barium titanate films for gas sensing

    NASA Astrophysics Data System (ADS)

    Romh, M. A. El; Fasquelle, D.; Députier, S.; Mascot, M.

    2014-11-01

    Barium titanate (BaTiO3) thick films were prepared from commercial powder to develop and optimize the film elaboration. Then, BaTiO3 was doped by strontium and iron to increase the conductivity by a double substitution on site A and B of the perovskite structure in view to develop semiconductor gas sensors. Film inks were prepared by mixing BT and BSTF powder with an organic vehicle, using a ratio of 50:50; 60:40, respectively and deposited on alumina substrates. The BT and BSTF films were sintered at 1100°C for 2h. The structural and physical properties of the films have been studied by using X-ray diffraction (XRD) and scanning electron microscope (SEM). The dielectric measurements showed a huge increase in the a.c. conductivity for the BSTF films, by a factor of 10000 at low frequency, when the temperature ranges from 25°C to 500°C.

  9. Structural and optical absorption studies of barium substituted strontium ferrite powder

    NASA Astrophysics Data System (ADS)

    Jaiswal, Shivendra Kumar; Kumar, Jitendra

    2012-08-01

    Attempt has been made to synthesize BaxSr1-xFeO3-? (x = 0-1.0) ferrite powder by decomposition of sol-gel derived oxalate at 800-1000 °C for 5-10 h to study the effect of barium insertion with regard to phase(s), stability, optical behavior, oxidation states of iron, and oxygen deficiency. It is shown that these ferrites possess a perovskite-type cubic phase (a = 3.877-4.020Å, Z = 1, space group Pm3m) for 0.1 ? x ? 0.94, a mixture of 82% rhombohedral (aR = 5.666Å and ?R = 59.761°, Z = 2, space group R3c) and 18% hexagonal phases for x = 0.96 and a pure hexagonal (a = 5.689Å, c = 13.944Å, Z = 6, space group P63/mmc) phase for x = 1. Barium substitution in SrFeO3-? system leads to lattice expansion, weakening of the metal-oxygen bond, reduction of tetravalent iron ions (as evident from Mossbauer analysis), and decrease of oxygen content. The optical absorption peaks observed in the range 3.17-4.11 eV are attributed to charge transfer transitions from O2- (2p) to Fe (3d) band. The values of optical energy band gap of BaxSr1-xFeO3-? are found to be ˜5.48 and ˜4.04 for x = 0.1 and 1.0, respectively. A stable perovskite-type cubic phase in BaxSr1-xFeO3-? system with significant anion deficiency (? = 0.26-0.32) may possibly act as an oxygen permeable membrane.

  10. [Ceruloplasmin, hephaestin and zyklopen: the three multicopper oxidases important for human iron metabolism].

    PubMed

    Wierzbicka, Diana; Gromadzka, Grazyna

    2014-01-01

    Multi-copper oxidases are a group of proteins which demonstrate enzymatic activity and are capable of oxidizing their substrates with the concomitant reduction of dioxygen to two water molecules. For some multi-copper oxidases there has been demonstrated ferroxidase activity which is related to their specific structure characterized by the presence of copper centres and iron-binding sites. Three multi-copper oxidases have been included in this group: ceruloplasmin, hephaestin and zyklopen. Multi-copper oxidases which are expressed in different tissues are capable of oxidizing a wide spectrum of substrates. Multi-copper oxidases are capable of oxidizing a wide spectrum of substrates. Ceruloplasmin exhibits antioxidant activity as well as being involved in many other biological processes. The observations of phenotypic effects of absence or low expression of multi-copper ferroxidase-coding genes suggest that the main role of these proteins is taking part in iron metabolism. The main role of ceruloplasmin in iron turnover is oxidizing Fe2+ into Fe3+, a process which is essential for iron binding to transferrin (the main iron-transporting protein), as well as to ferritin (the main iron-storage protein). The function of hephaestin as ferroxidase is essential for iron binding to apotransferrin in the lamina propria of the intestinal mucosa, a process that is important for further transport of iron to the liver by the portal vein. Available data indicate that zyklopen is responsible for the placental iron transport. The presence of three multi-copper oxidases with ferroxidase activity emphasizes the significance of oxidation for iron metabolism. The distribution of multi-copper ferroxidases in many tissues ensures the proper iron turnover in the body as well as preventing toxic effects related to the presence of Fe2+ ions. These ions contribute to generation of free radicals, including the highly reactive hydroxyl radical, through the Fenton and Haber-Weiss reactions. PMID:24988611

  11. Normal State Transport in Superconducting Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA) and Semiconducting Praseodymium BARIUM(2) COPPER(3) OXYGEN(7-DELTA)

    NASA Astrophysics Data System (ADS)

    Browning, Valerie Michelle

    1995-01-01

    The discovery, in 1986, of materials with superconducting transition temperatures well above 77 K has generated a renewed interest in potential applications for superconductors. Unfortunately, the widespread use of high temperature superconductors (HTS) has not been realized due to their poor performance in terms of electrical and physical properties. Although the mechanism of high temperature superconductivity remains a mystery, it is hoped that an understanding of the HTS will result in the ability to engineer better quality materials. The normal state of the HTS exhibits several features which are considered unusual. Among these features are a linear temperature dependence of the resistivity and a temperature dependent Hall effect. It is believed that knowledge of the normal state transport properties of the HTS is crucial to understanding superconductivity in these materials. In an effort to better understand the normal state of the these materials, the transport properties of single crystal samples of two members of the superconducting RBa_2Cu_3O _{7-delta} ("123") family were studied (R = yttrium and many of the rare earth elements). Resistivity, Hall effect, and magnetoresistance measurements were performed on a detwinned single crystal sample of YBa_2Cu_3 _{7-delta} (Y 123). Measurements were repeated after various oxygen anneals to study the effects of oxygen inhomogeneities on the sample's transport properties. These results indicate that oxygen inhomogeneities strongly influence the transport properties of this system. A model is presented which takes into account oxygen defects in calculating the resistivity and Hall coefficient. Of the rare earth elements that will form the 123 structure, only PrBa_2Cu _3O_{7-delta} (Pr 123) does not superconduct. Pr 123 exhibits a non-metallic temperature dependent resistivity as opposed to the metallic resistivity exhibited by the superconducting 123 family members. Magnetotransport and magnetization measurements were performed on a single crystal sample of Pr 123. These measurements show a correlation between the magnetic state of the Pr ion and transport in the Cu -O planes. Based on these results, an explanation of the "anomalous" behavior of Pr 123 is given.

  12. Electrical and Magnetic Properties of the Percolative Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA) - YTTRIUM(2) Barium Copper OXYGEN(5) Systems

    NASA Astrophysics Data System (ADS)

    Sedghi Gamchi, Hassan

    1995-01-01

    The electrical and magnetic behaviour of the mixed two phase, percolative system, YBCO(123)-YBCO(211) has been investigated. The normal-state resistivity of this system is best represented by a variable range hopping (VRH) model in which the electronic states of the system are localized. From this model the localization length, alpha^{-1} and the activation energies involved in the hopping process have been determined. The form of the superconducting resistive transition is shown to depend strongly on the intergranular weak-link structure. The resistivity tails have been interpreted in terms of the phase slip and thermally activated flux creep models with the magnetic field dependence of the activation energies found to follow an inverse power-law relationship. A detailed investigation of the ac magnetic susceptibility of this system has shown that the flux pinning energies were found to decrease rapidly as the Y_ {211} concentration increased. These measurements support the view that the observed pinning is associated with the intergranular weak-link system rather than with the intrinsic crystalline material. Changes in the H-T phase diagram have been established as a function of composition and it is found that the irreversibility line (IL) is consistent with H^{rm q}~ (1-t), while the IL moves to lower temperatures and magnetic fields as the intergranular pinning strengths are decreased. DC field dependent ac susceptibility results have been adequately described by a critical state model in which the critical current density is given by alpha(T)/(H_{rm o} + H_{{dc }})^{rm n}. The functional relationship of the material dependent parameter alpha(T) has been determined. The hysteresis behaviour of chi_{ {ac}} H_ {{dc}} in a cycled dc magnetic field have been measured and the average lower critical field, H_{{clg }} for the superconducting grains has been established and its temperature dependence determined. The internal relationship between the susceptibility components chi^{'} _{{ac}} and chi^{''} _{{ac}} have been investigated theoretically and experimentally. A significant difference exists between the observed and predicted results which has been discussed.

  13. Superplastic Deformation of High Transition Temperature Superconductors: Yttrium BARIUM(2), COPPER(3) OXYGEN(7 - and Yttrium BARIUM(2) COPPER(3) OXYGEN(7-X) Silver.

    NASA Astrophysics Data System (ADS)

    Yun, Jondo

    Superplasticity in the rm YBa_2Cu _3O_{7-x} ceramic superconductor and composites containing 2.5-25% silver was studied. Large deformation over 100% was observed in these materials in the temperature range of 775-875^circ C at strain rates of 1times10^ {-5} to 1times10^ {-3}/sec and grain sizes of 0.5-1.4 mum. The nature of the deformation behavior was investigated in terms of three deformation parameters: the stress exponent (n); grain size exponent (p); and activation energy (Q). For both the undoped and Ag-doped materials n = 2, p cong 2.5, and Q cong 750kJ/mol. By constructing the deformation map, the deformation mechanism was identified as grain boundary sliding accommodated by grain boundary diffusion, controlled by either the interface reaction rate at the grain boundary, or grain boundary sliding rate. The conclusion was consistent with microstructural observations made under the light optical microscope, scanning electron microscope, and transmission electron microscope. These observations show a lack of significant dislocation activity and intergranular second phase, insignificant texture development, and the maintenance of equiaxed grain shape. The superplastic deformation behavior of the composites followed the soft inclusion model of Chen. The effect of superplastic deformation on superconductivity was also examined. For rm YBa_2Cu _3O_{7-x}, T_{c } remained unchanged with deformation. For the composite, T_{rm c} generally decreased after deformation. It was found that the oxygenation rate was decreased with deformation in the presence of silver.

  14. Copper deficiency has minimal impact on ferroportin expression or function.

    PubMed

    Prohaska, Joseph R; Broderius, Margaret

    2012-08-01

    Interactions between copper and iron homeostasis have been known since the nineteenth century when anemia in humans was first described due to copper limitation. However, the mechanism remains unknown. Intestinal and liver iron concentrations are usually higher following copper deficiency (CuD). This may be due to impaired function of the multicopper oxidases hephaestin or ceruloplasmin (Cp), respectively. However, iron retention could be due to altered ferroportin (Fpn), the essential iron efflux transporter in enterocytes and macrophages. Fpn mRNA is controlled partially by intracellular iron and IRE dependence. CuD should augment Fpn based on iron level. Some argue that Fpn stability is controlled partially by membrane ferroxidase (GPI-Cp). CuD should result in lower Fpn since GPI-Cp expression and function is reduced. Fpn turnover is controlled by hepcidin. CuD results in variable Hamp (hepcidin) expression. Fpn mRNA and protein level were evaluated following dietary CuD in rats and mice. To correlate with Fpn expression, measurements of tissue iron were conducted in several rodent models. Following CuD there was little change in Fpn mRNA. Previous work indicated that under certain circumstances Fpn protein was augmented in liver and spleen following CuD. Fpn levels in CuD did not correlate with either total iron or non-heme iron (NHI), as iron levels in CuD liver were higher and in spleen lower than copper adequate controls. Fpn steady state levels appear to be regulated by a complex set of factors. Changes in Fpn do not explain the anemia of CuD. PMID:22294464

  15. Barium determination in gastric contents, blood and urine by inductively coupled plasma mass spectrometry in the case of oral barium chloride poisoning.

    PubMed

    ?ukasik-G??bocka, Magdalena; Sommerfeld, Karina; Han?, Anetta; Grzegorowski, Adam; Bara?kiewicz, Danuta; Gaca, Micha?; Zieli?ska-Psuja, Barbara

    2014-01-01

    A serious case of barium intoxication from suicidal ingestion is reported. Oral barium chloride poisoning with hypokalemia, neuromuscular and cardiac toxicity, treated with intravenous potassium supplementation and hemodialysis, was confirmed by the determination of barium concentrations in gastric contents, blood, serum and urine using the inductively coupled plasma mass spectrometry method. Barium concentrations in the analyzed specimens were 20.45 µg/L in serum, 150 µg/L in blood, 10,500 µg/L in urine and 63,500 µg/L in gastric contents. Results were compared with barium levels obtained from a non-intoxicated person. PMID:24794066

  16. Thermodynamics of Iron Oxidation in Metallurgical Slags

    NASA Astrophysics Data System (ADS)

    Matousek, Jan

    2012-11-01

    The state of oxidation of a pyrometallurgical process, given by the partial pressure of oxygen and the temperature, is one of the important properties monitored and controlled in the smelting and refining of iron and the nonferrous metals. This article reviews the thermodynamic background for this quantity and examines some empirical methods for its estimation and use. The emphasis is on copper smelting, but the same principles apply to iron, nickel, lead, and zinc processes.

  17. Green tea catechins as brain-permeable, non toxic iron chelators to "iron out iron" from the brain.

    PubMed

    Mandel, S; Weinreb, O; Reznichenko, L; Kalfon, L; Amit, T

    2006-01-01

    Evidence to link abnormal metal (iron, copper and zinc) metabolism and handling with Parkinson's and Alzheimer's diseases pathology has frequently been reported. The capacity of free iron to enhance and promote the generation of toxic reactive oxygen radicals has been discussed numerous times. Metal chelation has the potential to prevent iron-induced oxidative stress and aggregation of alpha-synuclein and beta-amyloid peptides. The efficacy of iron chelators depends on their ability to penetrate the subcellular compartments and cellular membranes where iron dependent free radicals are generated. Thus, natural, non-toxic, brain permeable neuroprotective drugs, are preferentially advocated for "ironing out iron" from those brain areas where it preferentially accumulates in neurodegenerative diseases. This review will discuss the most recent findings from in vivo and in vitro studies concerning the transitional metal (iron and copper) chelating property of green tea, and its major polyphenol, (-)-epigallocatechin-3-gallate with respect to their potential for the treatment of neurodegenerative diseases. PMID:17447435

  18. Impact of Copper Limitation on Expression and Function of Multicopper Oxidases (Ferroxidases)12

    PubMed Central

    Prohaska, Joseph R.

    2011-01-01

    Copper is an essential trace element whose recommended intake is met by most North American diets. However, incidence of new cases of secondary copper deficiency is rising due to complications of gastric bypass surgery and high zinc exposure. Patients frequently are ataxic and anemic. Anemia of copper deficiency was first described in the 19th century, but the underlying biochemistry remains unknown. Approximately one dozen cuproenzymes have been characterized in mammals. Four of these are referred to as multicopper oxidases (MCO) due to their copper binding geometries. They have iron oxidase activity (ferroxidase). These include the hepatic secreted protein ceruloplasmin representing ?90% of plasma copper, a splice-variant of ceruloplasmin originally characterized in brain linked by glycosylphosphatidylinositol (GPI) to membranes, an intestinal enriched MCO named hephaestin, and newly described MCO in placenta called zyklopen. Limitation in available copper appears to limit function of the MCO group exhibited as impaired iron flux due to the copper requirement of MCO for their ferroxidase activity. Dietary copper deficiency is associated with lower levels of ceruloplasmin, GPI-ceruloplasmin, and hephaestin. Limitation of copper does not appear to limit synthesis of MCO but rather their stability and turnover. However, there appears to be a disconnect between limitation in MCO function and anemia, because humans and mice missing ceruloplasmin are not anemic despite hepatic iron overload and hypoferremia. Furthermore, anemic copper-deficient mammals are not improved by iron replacement. This suggests that the anemia of copper deficiency is not caused by iron limitation but rather impairment in iron utilization. PMID:22332037

  19. Impact of copper limitation on expression and function of multicopper oxidases (ferroxidases).

    PubMed

    Prohaska, Joseph R

    2011-03-01

    Copper is an essential trace element whose recommended intake is met by most North American diets. However, incidence of new cases of secondary copper deficiency is rising due to complications of gastric bypass surgery and high zinc exposure. Patients frequently are ataxic and anemic. Anemia of copper deficiency was first described in the 19th century, but the underlying biochemistry remains unknown. Approximately one dozen cuproenzymes have been characterized in mammals. Four of these are referred to as multicopper oxidases (MCO) due to their copper binding geometries. They have iron oxidase activity (ferroxidase). These include the hepatic secreted protein ceruloplasmin representing ?90% of plasma copper, a splice-variant of ceruloplasmin originally characterized in brain linked by glycosylphosphatidylinositol (GPI) to membranes, an intestinal enriched MCO named hephaestin, and newly described MCO in placenta called zyklopen. Limitation in available copper appears to limit function of the MCO group exhibited as impaired iron flux due to the copper requirement of MCO for their ferroxidase activity. Dietary copper deficiency is associated with lower levels of ceruloplasmin, GPI-ceruloplasmin, and hephaestin. Limitation of copper does not appear to limit synthesis of MCO but rather their stability and turnover. However, there appears to be a disconnect between limitation in MCO function and anemia, because humans and mice missing ceruloplasmin are not anemic despite hepatic iron overload and hypoferremia. Furthermore, anemic copper-deficient mammals are not improved by iron replacement. This suggests that the anemia of copper deficiency is not caused by iron limitation but rather impairment in iron utilization. PMID:22332037

  20. Electrooptic and piezoelectric measurements in photorefractive barium titanate and strontium barium niobate

    SciTech Connect

    Ducharme, S.; Feinberg, J.; Neurgaonkar, R.R.

    1987-12-01

    The authors measured the low-frequency (''unclamped'') electrooptic and piezoelectric coefficients in undoped BaTiO/sub 3/ and Sr/sub x/Ba/sub 1-x/Nb/sub 2/O/sub 6/ (chi - 0.61) crystals using interferometric techniques. The contribution of the piezoelectric effect to the Pockels measurement is discussed. For an applied ac electric field in the range 0.1-200 V/cm, the electrooptic and piezoelectric effects are linear in the magnitude of of the applied field and independent of its frequency in the range of 10 Hz-100 kHz. The unclamped electrooptic coefficients of poled BaTiO/sub 3/ single crystals are r/sub 13/ = 19.5 +- 1 pm/V and r/sub 33/ = 97 +- 7 pm/V, and for strontium barium niobate are r/sub 13/ = 47 +- 5 pm/V and r/sub 33/ = 235 +- 21 pm/V, all measured at a wavelength of 514.5 nm and at T = 23/sup 0/C. For the barium titanate samples the measured Pockels coefficient r/sub c/ identical to r/sub 33/ - (n/sub 1//n/sub 3/)/sup 3/r/sub 13/ = 79 +- 6 pm/V in good agreement with the value r/sub c/ = 76 +- 7 pm/V computed from the above values of r/sub 13/ and r/sub 33/, where n/sub 1/ and n/sub 3/ are the ordinary and extraordinary indexes of refraction, respectively. The measured piezoelectric coefficient is d/sub 23/ = +28.7 +- 2 pm/V for barium titanate, and is d/sub 23/ = +24.6 +- 2 pm/V for strontium barium niobate. They also measured the photoreflective coupling of two optical beams in the crystals, and they show that the dependence of the coupling strength on beam polarization is in fair agreement with the measured values of the Pockels coefficients.

  1. Copper Data Center Database

    NSDL National Science Digital Library

    Copper Development Association

    The Copper Data Center Database is provided free of charge by the Copper Development Association "to increase knowledge and awareness of copper, related technologies, and the role of copper in the environment." The database is an online bibliographic search engine of literature on copper, copper alloys and copper technology dating back to 1965 and is described as covering copper technology from smelting and hydrometallurgy through the performance of copper and copper alloys in their end-use applications and service environments. Users can search by standard methods including using keywords and titles or an impressive advanced search feature is also available. Although full text listings are not available, anyone interested in related subjects will appreciate this well designed and unique tool.

  2. Induction of siderophore activity in Anabaena spp. and its moderation of copper toxicity

    SciTech Connect

    Clarke, S.E.; Stuart, J.; Sanders-Loehr, J.

    1987-05-01

    Growth of Anabaena sp. strain 7120 (in the absence of chelators or added iron) was inhibited by the addition of 2.1 to 6.5 ..mu..M copper and was abolished by copper concentrations of 10 /sup +/M or higher. When the copper was chelated to schizokinen, the toxic effects were eliminated. Analysis of culture filtrates showed that the cupric schizokinen remains in the medium, thereby lowering the amount of copper taken up by the cells. Although this organism actively transports ferric schizokinen, it apparently does not recognize the cupric complex. Thus, Anabaena sp. is protected from copper toxicity under conditions in which siderophore is being produced. For cells grown in low iron, the accumulation of extracellular schizokinen was observed to parallel cell growth and continue well into stationary phase. The actual iron status of the organism was monitored by using iron uptake velocity as an assay. Cultures grown on 0.1 ..mu..M added iron were found to be severely iron limited upon reaching stationary phase, thus explaining the continued production of schizokinen. These data show that the siderophore system in Anabaena spp. has developed primarily as a response to iron starvation and that additional functions such as alleviation of copper toxicity or allelopathic inhibition of other algal species are merely secondary benefits.

  3. Iron chelators and iron toxicity

    Microsoft Academic Search

    Gary M. Brittenham

    2003-01-01

    Iron chelation may offer new approaches to the treatment and prevention of alcoholic liver disease. With chronic excess, either iron or alcohol alone may individually injure the liver and other organs. In combination, each exaggerates the adverse effects of the other. In alcoholic liver disease, both iron and alcohol contribute to the production of hepatic fibrosis through their effects on

  4. Iron Oxide-Supported Copper Oxide Nanoparticles (Nanocat-Fe-CuO): Magnetically Recyclable Catalysts for the Synthesis of Pyrazole Derivatives, 4-Methoxyaniline, and Ullmann-type Condensation Reactions

    EPA Science Inventory

    An efficient and benign protocol is reported for the synthesis of 4-methoxyaniline, medicinally important pyrazole derivatives, and Ullmann-type condensation reaction using magnetically separable and reusable magnetite-supported copper (nanocat-Fe-CuO) nanoparticles under mild co...

  5. Genetic analysis of iron uptake in the yeast Saccharomyces cerevisiae

    Microsoft Academic Search

    Andrew Dancis

    1998-01-01

    Objective: We used the methods of yeast genetics to identify genes involved in acquisition of iron by eukaryotic cells. Methods: Mutants were identified with defects in cellular iron uptake. These were organized into an upstream group and a downstream group. The upstream group was involved in the delivery of copper to the multicopper oxidase FET3. Mutants of this group were

  6. Occurrence and Distribution of Iron, Manganese, and Selected Trace Elements in Ground Water in the Glacial Aquifer System of the Northern United States

    USGS Publications Warehouse

    Groschen, George E.; Arnold, Terri L.; Morrow, William S.; Warner, Kelly L.

    2009-01-01

    Dissolved trace elements, including iron and manganese, are often an important factor in use of ground water for drinking-water supplies in the glacial aquifer system of the United States. The glacial aquifer system underlies most of New England, extends through the Midwest, and underlies portions of the Pacific Northwest and Alaska. Concentrations of dissolved trace elements in ground water can vary over several orders of magnitude across local well networks as well as across regions of the United States. Characterization of this variability is a step toward a regional screening-level assessment of potential human-health implications. Ground-water sampling, from 1991 through 2003, of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey determined trace element concentrations in water from 847 wells in the glacial aquifer system. Dissolved iron and manganese concentrations were analyzed in those well samples and in water from an additional 743 NAWQA land-use and major-aquifer survey wells. The samples are from monitoring and water-supply wells. Concentrations of antimony, barium, beryllium, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, selenium, strontium, thallium, uranium, and zinc vary as much within NAWQA study units (local scale; ranging in size from a few thousand to tens of thousands of square miles) as over the entire glacial aquifer system. Patterns of trace element concentrations in glacial aquifer system ground water were examined by using techniques suitable for a dataset with zero to 80 percent of analytical results reported as below detection. During the period of sampling, the analytical techniques changed, which generally improved the analytical sensitivity. Multiple reporting limits complicated the comparison of detections and concentrations. Regression on Order Statistics was used to model probability distributions and estimate the medians and other quantiles of the trace element concentrations. Strontium and barium were the most frequently detected and usually were present in the highest concentrations. Iron and manganese were the next most commonly detected and next highest in concentrations. Iron concentrations were the most variable with respect to the range of variations (both within local networks and aquifer-wide) and with respect to the disparity between magnitude of concentrations (detections) and the frequency of samples below reporting limits (nondetections). Antimony, beryllium, cadmium, silver, and thallium were detected too infrequently for substantial interpretation of their occurrence or distributions or potential human-health implications. For those elements that were more frequently detected, there are some geographic patterns in their occurrence that primarily reflect climate effects. The highest concentrations of several elements were found in the West-Central glacial framework area (High Plains and northern Plains areas). There are few important patterns for any element in relation to land use, well type, or network type. Shallow land-use (monitor) wells had iron concentrations generally lower than the glacial aquifer system wells overall and much lower than major-aquifer survey wells, which comprise mostly private- and public-supply wells. Unlike those for iron, concentration patterns for manganese were similar among shallow land-use wells and major-aquifer survey wells. An apparent relation between low pH and relatively low concentrations of many elements, except lead, may be more indicative of the relatively low dissolved-solids content in wells in the Northeastern United States that comprise the majority of low pH wells, than of a pH dependent pattern. Iron and manganese have higher concentrations and larger ranges of concentrations especially under more reducing conditions. Dissolved oxygen and well depth were related to iron and manganese concentrations. Redox conditions also affect several trace elements such

  7. High H? ionic conductivity in barium hydride.

    PubMed

    Verbraeken, Maarten C; Cheung, Chaksum; Suard, Emmanuelle; Irvine, John T S

    2015-01-01

    With hydrogen being seen as a key renewable energy vector, the search for materials exhibiting fast hydrogen transport becomes ever more important. Not only do hydrogen storage materials require high mobility of hydrogen in the solid state, but the efficiency of electrochemical devices is also largely determined by fast ionic transport. Although the heavy alkaline-earth hydrides are of limited interest for their hydrogen storage potential, owing to low gravimetric densities, their ionic nature may prove useful in new electrochemical applications, especially as an ionically conducting electrolyte material. Here we show that barium hydride shows fast pure ionic transport of hydride ions (H(-)) in the high-temperature, high-symmetry phase. Although some conductivity studies have been reported on related materials previously, the nature of the charge carriers has not been determined. BaH2 gives rise to hydride ion conductivity of 0.2 S cm(-1) at 630 °C. This is an order of magnitude larger than that of state-of-the-art proton-conducting perovskites or oxide ion conductors at this temperature. These results suggest that the alkaline-earth hydrides form an important new family of materials, with potential use in a number of applications, such as separation membranes, electrochemical reactors and so on. PMID:25485988

  8. Enhancement of Beam Fanning in Barium Titanate

    NASA Astrophysics Data System (ADS)

    Smith, Neil; Yarrison-Rice, Jan

    2001-10-01

    We have made initial measurements of the temporal evolution of beam fanning in photorefractive crystals with and without the use of a diffuser at the sample's input plane. Beam fanning is initiated through two beam coupling between the incident radiation and the light which scatters from impurities at or near the input plane of the crystal. An index of refraction grating is formed between input beam and the scattered beams in the +c-axis direction due to the electro-optic effect. As the index grating grows in strength more light is diverted into the scattered beams' direction. The result is a beam fan that is collected via a series of lenses and is imaged unto a CCD camera that records the build up as a function of time. A diffusing plate placed at the entrance face of the barium titanate increases the scattering of the incident beam. This allows more energy to be diverted from the propagating beam into the scattered beams and thus into the beam fan. The diffuser has been characterized with AFM measurements and typical width and heights of surface features are recorded. An imaging software package provides a method of analyzing the total intensity of the beam fan as it develops and times to steady state are determined. We find that beam fanning efficiency is enhanced with the diffuser.

  9. Prospects for Barium Tagging in Gaseous Xenon

    SciTech Connect

    Sinclair, D.; /Carleton U. /TRIUMF; Rollin, E.; /Carleton U.; Smith, J.; /Carleton U.; Mommers, A.; /Ottawa U.; Ackerman, N.; /SLAC; Aharmim, B.; /Laurentian U.; Auger, M.; /Bern U., LHEP; Barbeau, P.S.; /Stanford U., Phys. Dept.; Benitez-Medina, C.; /Colorado State U.; Breidenbach, M.; /SLAC; Burenkov, A.; /Moscow, ITEP; Cook, S.; /SLAC; Coppens, A.; /Carleton U.; Daniels, T.; /Massachusetts U., Amherst; DeVoe, R.; /Stanford U., Phys. Dept.; Dobi, A.; /Maryland U.; Dolinski, M.J.; Donato, K.; /Stanford U., Phys. Dept.; Fairbank, W., Jr.; /Colorado State U.; Farine, J.; /Laurentian U.; Giroux, G.; /Bern U., LHEP /Carleton U. /Stanford U., Phys. Dept. /Carleton U. /Laurentian U. /Carleton U. /SLAC /Indiana U. /Indiana U., CEEM /Korea U. /Stanford U., Phys. Dept. /SLAC /Alabama U. /Colorado State U. /Stanford U., Phys. Dept. /Alabama U. /SLAC /Stanford U., Phys. Dept. /Alabama U. /Massachusetts U., Amherst /SLAC /Alabama U. /SLAC /Maryland U. /Moscow, ITEP /Stanford U., Phys. Dept. /Maryland U. /Bern U., LHEP /Laurentian U. /SLAC /Maryland U.

    2012-05-03

    Tagging events with the coincident detection of a barium ion would greatly reduce the background for a neutrino-less double beta decay search in xenon. This paper describes progress towards realizing this goal. It outlines a source that can produce large quantities of Ba++ in gas, shows that this can be extracted to vacuum, and demonstrates a mechanism by which the Ba++ can be efficiently converted to Ba+ as required for laser identification. It is clear from this study that electrospray is a convenient mechanism for producing Ba++ is gas at atmospheric pressure. It is likely that the source will perform just as effectively at higher pressures. Even though the source region has water vapour and methanol vapour at the 0.3% level, there is no evidence for molecular formation. The use of TEA offers an effective method to achieve the charge state conversion. The overall design of the ion extraction from high pressure to vacuum is very similar to the scheme proposed for the final detector and this appears to work well although the efficiency is not yet determined.

  10. Pyroelectric properties of barium strontium titanate films: Effect of thermal M. W. Cole,2

    E-print Network

    Alpay, S. Pamir

    Pyroelectric properties of barium strontium titanate films: Effect of thermal stresses J. Zhang,1 M pyroelectric properties of 001 -textured polycrystalline barium strontium titanate BaxSr1-xTiO3, BST films

  11. Enhanced dielectric properties from barium strontium titanate films with strontium titanate buffer layers

    E-print Network

    Alpay, S. Pamir

    Enhanced dielectric properties from barium strontium titanate films with strontium titanate buffer in their PE state. One of the leading material candidates for tunable materials is barium strontium titanate

  12. SHS of YBa 2Cu 3O 6+ x using large copper particles

    NASA Astrophysics Data System (ADS)

    Lin, Sy-Chyi; Li, Dong X.; Semiat, R.; Richardson, James T.; Luss, Dan

    1993-12-01

    YBa 2Cu 3O 6+ x was produced by self-propagating high-temperature synthesis (SHS) from copper, barium peroxide, and yttrium oxide. In contrast to previous studies, a stable reaction front coule be maintained even when using relatively large copper particles (smaller than 325 mesh). Large pellets (larger than 22 mm in diameter) were combusted at room temperature. Elevated ambient temperatures (400-500°C) were used to stabilize the combustion front movements in small pellets. A high-quality product may be obtained by a very short sintering at 950-970°C in an oxygen atmosphere following the SHS. The influence of copper-particle size, starting density and post-heat treatment were studied. An explanation of the influence of the copper particle size on the reaction stability is proposed.

  13. Acceleration of barium ions near 8000 km above an aurora

    NASA Technical Reports Server (NTRS)

    Stenbaek-Nielsen, H. C.; Hallinan, T. J.; Wescott, E. M.; Foeppl, H.

    1984-01-01

    A barium shaped charge, named Limerick, was released from a rocket launched from Poker Flat Research Range, Alaska, on March 30, 1982, at 1033 UT. The release took place in a small auroral breakup. The jet of ionized barium reached an altitude of 8100 km 14.5 min after release, indicating that there were no parallel electric fields below this altitude. At 8100 km the jet appeared to stop. Analysis shows that the barium at this altitude was effectively removed from the tip. It is concluded that the barium was actually accelerated upward, resulting in a large decrease in the line-of-sight density and hence the optical intensity. The parallel electric potential in the acceleration region must have been greater than 1 kV over an altitude interval of less than 200 km. The acceleration region, although presumably auroral in origin, did not seem to be related to individual auroral structures, but appeared to be a large-scale horizontal structure. The perpendicular electric field below, as deduced from the drift of the barium, was temporally and spatially very uniform and showed no variation related to individual auroral structures passing through.

  14. Emission spectrographic determination of barium in sea water using a cation exchange concentration procedure

    USGS Publications Warehouse

    Szabo, B. J.; Joensuu, O.

    1967-01-01

    A concentration technique employing Dowex 50W cation exchange resin is described for the determination of barium in sea water. The separated barium is precipitated as fluoride together with calcium and strontium and measured by emission spectrographic analysis. The vertical distribution of barium in sea water has been measured in the Caribbean Sea and the Atlantic Ocean. The barium content varied between 7 and 23 ??g. per liter; in two profiles, the lowest concentrations were at a depth of about 1000 meters.

  15. Radiation dose in mass screening for gastric cancer with high-concentration barium sulfate compared with moderate-concentration barium sulfate.

    PubMed

    Yamamoto, K; Azuma, M; Kuroda, C; Kubo, T; Yabunaka, K; Yamazaki, H; Katsuda, T; Takeda, Y

    2009-06-01

    Recently, high-concentration barium sulfate has been developed and is used in many medical facilities. This study compared radiation dose using high-concentration and moderate-concentration barium sulfate. The dose was evaluated with an experimental method using a gastric phantom and with a clinical examination. In the former, the dose and X-ray tube load were measured on the phantom with two concentrations of barium sulfate. In the latter, the fluoroscopic dose-area product (DAP), the radiographic DAP and their sum, the total DAP, were investigated in 150 subjects (112 males, 38 females) treated with both concentrations of barium sulfate. The effective dose was calculated by the software of PCXMC in every case. The results of the experimental evaluation indicated that the effective dose and X-ray tube load were greater with high-concentration barium sulfate than with moderate-concentration barium sulfate (p < 0.05). The results of the clinical evaluation indicated that the fluoroscopic DAP was greater with moderate-concentration barium sulfate than with high-concentration barium sulfate (p < 0.05), but the radiographic DAP was quite the reverse, so the total DAP and effective dose were almost same with both concentrations of barium sulfate. We conclude that high-concentration barium sulfate does not increase radiation dose in mass screening for gastric cancer. PMID:19623859

  16. L = 1.24 Conjugate Magnetic Field Line Tracing Experiments With Barium Shaped Charges

    Microsoft Academic Search

    E. M. Wescott; E. P. Rieger; H. C. Stenbaek-Nielsen; T. N. Davis; H. M. Peek; P. J. Bottoms

    1974-01-01

    Barium ions are well suited for tracing out magnetic field lines, because they resonantly scatter sunlight in several visible wavelengths and because ions are constrained to spiral about magnetic field lines while traveling freely parallel to the field. By use of high explosive shaped charges with hollow conical liners of barium metal, detonated above 500-km altitude, jets of barium plasma

  17. Technical development: CT colonography without cathartic cleansing and with barium as the sole tagging agent

    Microsoft Academic Search

    Philippe Lefere; Stefaan Gryspeerdt; Marc Baekelandt; Bartel Van Holsbeeck

    2004-01-01

    The purpose of this study was to perform CT colonography (CTC) without cathartic colon cleansing. Four groups of 3 patients were prepared the day before CTC with a dedicated low residue diet, a hydration control allowing 2 liters of fluid intake and barium as tagging agent. Four different barium regimens were investigated. Groups 1 and 3 ingested barium over 1

  18. 21 CFR 201.304 - Tannic acid and barium enema preparations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 201.304 Tannic acid and barium enema preparations. (a) It has become a widespread practice for tannic acid to be added to barium enemas to...

  19. 21 CFR 201.304 - Tannic acid and barium enema preparations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 201.304 Tannic acid and barium enema preparations. (a) It has become a widespread practice for tannic acid to be added to barium enemas to...

  20. 21 CFR 201.304 - Tannic acid and barium enema preparations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 201.304 Tannic acid and barium enema preparations. (a) It has become a widespread practice for tannic acid to be added to barium enemas to...

  1. Discrete Barium Strontium Titanate (BST) Thin-Film Interdigital Varactors on Alumina: Design, Fabrication, Characterization, and

    E-print Network

    Discrete Barium Strontium Titanate (BST) Thin-Film Interdigital Varactors on Alumina: Design, Raleigh, NC-27695-7914, USA. Email:jayeshnath@ieee.org Abstract -- Discrete Barium Strontium Titanate (BST, capacitors, BST, ferroelectric, thin-film, barium strontium titanate, bandpass filter, IP3, ACPR, temperature

  2. Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron

    E-print Network

    York, Robert A.

    Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron Abstract-- Barium strontium titanate is a solid solution perovskite with a field-dependent permittivity.7 MV/cm. I. INTRODUCTION In recent years there has been much interest in thin-film barium strontium

  3. Spectroscopy of Eu3+ ions in congruent strontium barium niobate crystals

    E-print Network

    Osnabrück, Universität

    Spectroscopy of Eu3+ ions in congruent strontium barium niobate crystals Ä. Andresen, A.-N. Bahar properties of single crystals of strontium barium niobate, grown from the congruently melting composition, electro-optic, pho- torefractive, and dielectric properties, the solid solution strontium barium niobate

  4. Introduction Strontium Barium Niobate k-Space Spectroscopy Results Conclusions Unraveling Relaxor Phase Transitions by

    E-print Network

    Osnabrück, Universität

    Introduction Strontium Barium Niobate k-Space Spectroscopy Results Conclusions Unraveling Relaxor 2009 WILLIAMSBURG WORKSHOP ON FUNDAMENTAL PHYSICS OF FERROELECTRICS #12;Introduction Strontium Barium ferroelectrics Introduction Strontium Barium Niobate k-Space Spectroscopy Results Conclusions SBN ­ SrxBa1-xNb2O6

  5. High tunability barium strontium titanate thin films for rf circuit applications

    E-print Network

    York, Robert A.

    High tunability barium strontium titanate thin films for rf circuit applications N. K. Pervez,a) P) Large variations in the permittivity of rf magnetron sputtered thin-film barium strontium titanate have/cm. © 2004 American Institute of Physics. [DOI: 10.1063/1.1818724] Barium strontium titanate (BST) is a solid

  6. Dielectric tunability of graded barium strontium titanate multilayers: Effect of thermal strains

    E-print Network

    Alpay, S. Pamir

    Dielectric tunability of graded barium strontium titanate multilayers: Effect of thermal strains M TEC of a multilayered barium strontium titanate Ba1-ySryTiO3 BST ferroelectric heterostructure such as barium strontium titanate Ba1-ySryTiO3 BST have emerged as leading candidates for such applications due

  7. Noncollinear Optical Frequency Doubling in Strontium Barium Niobate Arthur R. Tunyagi, Michael Ulex, and Klaus Betzler*

    E-print Network

    Osnabrück, Universität

    Noncollinear Optical Frequency Doubling in Strontium Barium Niobate Arthur R. Tunyagi, Michael Ulex of a novel noncollinear optical second-harmonic generation mechanism is reported. In strontium barium niobate mechanism which we detected in crystals of strontium barium niobate (SBN)--cone-shaped second

  8. Optimization of the tunability of barium strontium titanate films via epitaxial stresses

    E-print Network

    Alpay, S. Pamir

    Optimization of the tunability of barium strontium titanate films via epitaxial stresses Z.-G. Ban The tunability of epitaxial barium strontium titanate films is analyzed theoretically using a phenomenological.1063/1.1524310 I. INTRODUCTION Thin films of barium strontium titanate (BaxSr1 xTiO3, BST have long been recognized

  9. Barium Titanate Nanoparticles in Block Copolymer Tu Lee,*,, Nan Yao, Hiroaki Imai,, and Ilhan A. Aksay,

    E-print Network

    Aksay, Ilhan A.

    Barium Titanate Nanoparticles in Block Copolymer Tu Lee,*,, Nan Yao, Hiroaki Imai,, and Ilhan A-polybutadiene-polystyrene (Kraton D1102). The barium titanated Kraton thin film had remnants of the cylindrical morphology of a plain Kraton thin film with an interdomain spacing of 23 nm. The procedure of barium titanation

  10. 21 CFR 201.304 - Tannic acid and barium enema preparations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 201.304 Tannic acid and barium enema preparations. (a) It has become a widespread practice for tannic acid to be added to barium enemas to...

  11. 21 CFR 201.304 - Tannic acid and barium enema preparations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 201.304 Tannic acid and barium enema preparations. (a) It has become a widespread practice for tannic acid to be added to barium enemas to...

  12. Cation non-stoichiometry in yttrium-doped barium zirconate: phase behavior, microstructure, and proton conductivity

    E-print Network

    Cation non-stoichiometry in yttrium-doped barium zirconate: phase behavior, microstructure as the predominant secondary phase and the barium zirconate reverting to an undoped composition. From the relative conductivity. Barium zirconate, specifically yttrium-doped BaZrO3, has attracted particular attention amongst

  13. Enhanced Sintering of Yttrium-Doped Barium Zirconate by Addition of ZnO

    E-print Network

    Haile, Sossina M.

    Enhanced Sintering of Yttrium-Doped Barium Zirconate by Addition of ZnO Peter Babilo and Sossina M properties of doped barium zirconate have been examined. With the use of zinc ox- ide as a sintering aid, Ba of the material under flowing CO2 showed ZnO-modified barium zirconate to exhibit excellent chemical stability

  14. Defect Chemistry of Yttrium-Doped Barium Zirconate: A Thermodynamic Analysis of Water Uptake

    E-print Network

    Defect Chemistry of Yttrium-Doped Barium Zirconate: A Thermodynamic Analysis of Water Uptake-based SOFCs.3 Of known proton conducting oxides, yttrium-doped barium zirconate (BYZ) is particularly mobile species. Doping with trivalent yttrium onto the tetravalent zirconium in barium zirconate

  15. Copper promotion of high temperature shift

    Microsoft Academic Search

    John S. Coleman; Mang Zhang; Rainee M. VanNatter; Carl R. F. Lund

    2011-01-01

    A four-step, redox kinetic mechanism provides an accurate description of the rate of water-gas shift over ferrochrome catalysts. When the heats of formation of the surface intermediates in the model are decreased by only 10kJmol?1, as might be expected when copper cations substitute for iron cations in the oxide catalyst, the model predicts increased activity and decreased inhibition by CO2.

  16. The Viscous and Conductivity Behavior of Melts Containing Iron Oxide in the FeOt-SiO2-CaO-Cu2O System for Copper Smelting Slags

    NASA Astrophysics Data System (ADS)

    Huaiwei, Zhang; Fei, Sun; Xiaoyan, Shi; Bo, Zhang; Xin, Hong

    2012-10-01

    The control of the slag properties has become very essential in improving (1) the separation between the slag and the matte and (2) the operation of electric smelting furnaces in the copper pyrometallurgical process. The viscosities and electrical conductivities of FeOt-SiO2-CaO-Cu2O copper smelting slags were measured using the rotational spindle method and the standard direct-current (DC) four-probe method, respectively, in this article. The influences of the common constituents of CaO, Fe3O4, Cu2O in the basic slag system of FeO-SiO2 on the viscosity and conductivity have been investigated. The results showed that the effects of these three compositions on viscosity and conductivity were much more complicated due to the transition of the basic slag compositions. The apparent activity energy of viscosity and the relationship between viscosity and electrical conductivity are also mentioned in the study.

  17. Prompt ionization in the CRIT II barium releases

    NASA Astrophysics Data System (ADS)

    Torbert, R. B.; Kletzing, C. A.; Liou, K.; Rau, D.

    1992-05-01

    Observations of electron and ion distributions inside a fast neutral barium jet in the ionosphere show significant fluxes within 4 km of release, presumably related to beam plasma instability processes involved in the Critical Ionization Velocity (CIV) effect. Electron fluxes exceeding 5 x 10 exp 12/sq cm-str-sec-keV were responsible for ionizing both the streaming barium and ambient oxygen. Resulting ion fluxes seem to be consistent with 1-2 percent ionization of the fast barium, as reported by optical observations, although the extended spatial distribution of the optically observed ions is difficult to reconcile with the in situ observations. When the perpendicular velocity of the neutrals falls below critical values, these processes shut off. Although these observations resemble the earlier Porcupine experimental results (Haerendel, 1982), theoretical understanding of the differences between these data and that of earlier negative experiments is still lacking.

  18. Inert electrode containing metal oxides, copper and noble metal

    DOEpatents

    Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA); Dawless, Robert K. (Monroeville, PA); Hosler, Robert B. (Sarver, PA)

    2001-01-01

    A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

  19. Inert electrode containing metal oxides, copper and noble metal

    DOEpatents

    Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA); Dawless, Robert K. (Monroeville, PA); Hosler, Robert B. (Sarver, PA)

    2000-01-01

    A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

  20. Timed barium esophagram in achalasia types.

    PubMed

    Zanoni, A; Rice, T W; Lopez, R; Birgisson, S; Shay, S S; Thota, P N; Baker, M E; Raymond, D P; Blackstone, E H

    2015-01-01

    Relationships of timed barium esophagram (TBE) findings to achalasia types defined by high-resolution manometry (HRM) have not been elucidated. Therefore, we correlated preoperative TBE and HRM measurements in achalasia types and related these to patient symptoms and prior treatments. From 2006 to 2013, 248 achalasia patients underwent TBE and HRM before Heller myotomy. TBE height and width were recorded at 1 and 5 minutes; HRM measured lower esophageal sphincter mean basal pressure, integrated relaxation pressure (IRP), and mean esophageal body contraction amplitude. Achalasia was classified into types I (25%), II (65%), and III (9.7%). TBE height at 5 minutes was higher for I (median 8 cm; interquartile range 6-12) and II (8 cm; 8-11) than for III (1 cm; 0-7). TBE width at 5 minutes was widest (3 cm; 2-4), narrower in II (2 cm; 2-3), and narrowest in I (1 cm; 0-2), P < 0.001. Volume remaining at 1 and 5 minutes was lower in III (1 m(2) ; 0-16) than I (42 m(2) ; 17-106) and II (39 m(2) ; 15-60), highlighting poorer emptying of I and II. Increasing TBE width correlated with deteriorating morphology and function from III to II to I. Symptoms poorly correlated with TBE and HRM. Prior treatment was associated with less regurgitation, faster emptying, and lower IRP. Although TBE and HRM are correlated in many respects, the wide range of their measurements observed in this study reveals a spectrum of morphology and dysfunction in achalasia that is best characterized by the combination of these studies. PMID:24649871

  1. Barium Levels in Soils and Centella asiatica.

    PubMed

    Ong, Ghim Hock; Yap, Chee Kong; Mahmood, Maziah; Tan, Soon Guan; Hamzah, Suhaimi

    2013-08-01

    In this study, Centella asiatica and surface soils were collected from 12 sampling sites in Peninsular Malaysia, and the barium (Ba) concentrations were determined. The Ba concentration [?g/g dry weight (dw)] was 63.72 to 382.01 ?g/g in soils while in C. asiatica, Ba concentrations ranged from 5.05 to 21.88 ?g/g for roots, 3.31 to 11.22 ?g/g for leaves and 2.37 to 6.14 ?g/g for stems. In C. asiatica, Ba accumulation was found to be the highest in roots followed by leaves and stems. The correlation coefficients (r) of Ba between plants and soils were found to be significantly positively correlated, with the highest correlation being between roots-soils (r=0.922, p<005), followed by leaves-soils (r=0.890, p<005) and stems-soils (r=0.848, p<005). This indicates that these three parts of C. asiatica are good biomonitors of Ba pollution. For the transplantation study, four sites were selected as unpolluted [(Universiti Putra Malaysia (UPM)], semi-polluted (Seri Kembangan and Balakong) and polluted sites (Juru). Based on the transplantation study under experimental field and laboratory conditions, Ba concentrations in C. asiatica were significantly (p<0.05) higher after three weeks of exposure at Seri Kembangan, Balakong and Juru. Thus, these experimental findings confirm that the leaves, stems and roots of C. asiatica can reflect the Ba levels in the soils where this plant is found. Three weeks after back transplantation to clean soils, the Ba levels in C. asiatica were still higher than the initial Ba level even though Ba elimination occurred. In conclusion, the leaves, stems and roots of C. asiatica are good biomonitors of Ba pollution. PMID:24575242

  2. Tetrathiomolybdate Inhibits Copper Trafficking Proteins Through Metal Cluster Formation

    SciTech Connect

    Alvarez, Hamsell M.; Xue, Yi; Robinson, Chandler D.; Canalizo-Hernández, Mónica A.; Marvin, Rebecca G.; Kelly, Rebekah A.; Mondragón, Alfonso; Penner-Hahn, James E.; O’ Halloran, Thomas V. (Michigan); (NWU)

    2010-05-06

    Tetrathiomolybdate (TM) is an orally active agent for treatment of disorders of copper metabolism. Here we describe how TM inhibits proteins that regulate copper physiology. Crystallographic results reveal that the surprising stability of the drug complex with the metallochaperone Atx1 arises from formation of a sulfur-bridged copper-molybdenum cluster reminiscent of those found in molybdenum and iron sulfur proteins. Spectroscopic studies indicate that this cluster is stable in solution and corresponds to physiological clusters isolated from TM-treated Wilson's disease animal models. Finally, mechanistic studies show that the drug-metallochaperone inhibits metal transfer functions between copper-trafficking proteins. The results are consistent with a model wherein TM can directly and reversibly down-regulate copper delivery to secreted metalloenzymes and suggest that proteins involved in metal regulation might be fruitful drug targets.

  3. Characterization and recovery of copper values from discarded slag.

    PubMed

    Das, Bisweswar; Mishra, Barada Kanta; Angadi, Shivakumar; Pradhan, Siddharth Kumar; Prakash, Sandur; Mohanty, Jayakrushna

    2010-06-01

    In any copper smelter large quantities of copper slag are discarded as waste material causing space and environmental problems. This discarded slag contains important amounts of metallic values such as copper and iron. The recovery of copper values from an Indian smelter slag that contains 1.53% Cu, 39.8% Fe and 34.65% SiO(2) was the focus of the present study. A complete investigation of the different phases present in the slag has been carried out by means of optical microscopy, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. It is observed that iron and silica are mostly associated with the fayalite phase whereas copper is present in both oxide and sulfide phases. These oxide and sulfide phases of copper are mostly present within the slag phase and to some extent the slag is also embedded inside the oxide and sulfide phases. The recovery of copper values from the discarded slag has been explored by applying a flotation technique using conventional sodium isopropyl xanthate (SIX) as the collector. The effects of flotation parameters such as pH and collector concentration are investigated. Under optimum flotation conditions, it is possible to achieve 21% Cu with more than 80% recovery. PMID:19748952

  4. EFFECT of GROUND COPPER SLAG on the STRENGTH, and TOUGHNESS of CEMENTITIOUS MIXTURES

    E-print Network

    Mobasher, Barzin

    with disposal [1]. Blast-furnace slag is associated with iron production, has been effectively used blast furnace slag to be economical and durable [2]. Major copper producing regions of the United States1 EFFECT of GROUND COPPER SLAG on the STRENGTH, and TOUGHNESS of CEMENTITIOUS MIXTURES A.M. Ariño1

  5. DISSOLVED ORGANIC CARBON CHARACTERISTICS IN METAL-RICH WATERS AND THE IMPLICATIONS FOR COPPER AQUATIC TOXICITY

    EPA Science Inventory

    This research will aim to quantify the effects of fractionation between DOC, HFO, HAO, free copper and the behavior of resultant free DOC in the water column on the toxicological effects of copper. Fractionation between DOC, free metals and iron (Fe) and aluminum (Al) hydro...

  6. Barium Tagging from nEXO Using Resonance Ionization Spectroscopy

    NASA Astrophysics Data System (ADS)

    Twelker, K.; Kravitz, S.

    nEXO is a 5-ton liquid enriched-xenon time projection chamber (TPC) to search for neutrinoless double-beta decay, designed to have the sensitivity to completely probe the inverted mass hierarchy of Majorana neutrinos. The detector will accommodate-as a background reduction technique-a system to recover and identify the barium decay product. This upgrade will allow a background-free measurement of neutrinoless double-beta decay and increase the half-life sensitivity of the experiment by at least one order of magnitude. Ongoing research and development includes a system to test barium extraction from liquid xenon using surface adsorption and Resonance Ionization Spectroscopy (RIS).

  7. Tunable dielectric properties of lead barium zirconate niobate films

    NASA Astrophysics Data System (ADS)

    Kuo, Ya-Ling; Wu, Jenn-Ming

    2006-09-01

    The effect of substitution of niobium for zirconium on tunable behavior of lead barium zirconate (PBZ) films was investigated. Lead barium zirconate niobate films were grown on Pt /Ti/SiO2/Si substrates using chemical solution deposition method. The substitution of Nb for Zr enhances tunable properties of PBZ films. The dielectric tunabilities are excellent, all higher than 45% with a maximum=60%. The substitution of Nb for Zr raises values of figure of merit (FOM) of films. The maximum FOM takes place at 5mol% Nb with a value of 90, which is about three times that of the corresponding PBZ film.

  8. D-penicillamine treatment of copper-associated hepatitis in Labrador retrievers.

    PubMed

    Fieten, Hille; Dirksen, Karen; van den Ingh, Ted S G A M; Winter, Esther A; Watson, Adrian L; Leegwater, Peter A J; Rothuizen, Jan

    2013-06-01

    d-penicillamine is effectively used in the lifelong treatment of copper toxicosis in Bedlington terriers and Wilson's disease in humans. A complex form of copper-associated hepatitis has recently been characterized in the Labrador retriever. The aims of this study were to evaluate the effectiveness of d-penicillamine treatment for copper-associated hepatitis in this breed, to study the effects on hepatic copper, iron and zinc concentrations, and to evaluate parameters to predict optimal duration of treatment. Forty-three client owned Labrador retrievers that were diagnosed with increased hepatic copper were treated with d-penicillamine and underwent at least one follow-up examination including a liver biopsy for histopathological scoring of inflammatory lesions. Hepatic copper, iron and zinc concentrations were determined in the initial and follow-up biopsies by instrumental neutron activation analysis. The influence of initial hepatic copper concentration, sex, age, d-penicillamine formulation and the occurrence of side effects were investigated for their influence on hepatic copper concentration after a certain period of treatment by generalized mixed modelling. d-penicillamine proved to be effective in reducing hepatic copper concentration and associated inflammatory lesions. Parameters derived from the model can be used to estimate the necessary duration of d-penicillamine treatment for Labrador retrievers with increased hepatic copper concentration. Continuous, lifelong d-penicillamine treatment is not recommended in this breed, as there may be a risk for hepatic copper and zinc deficiency. PMID:23375251

  9. Role of microbial iron reduction in the dissolution of iron hydroxysulfate minerals

    Microsoft Academic Search

    Elizabeth J. P. Jones; Tracie-Lynn Nadeau; Mary A. Voytek; Edward R. Landa

    2006-01-01

    Iron-hydroxysulfate minerals can be important hosts for metals such as lead, mercury, copper, zinc, silver, chromium, arsenic, and selenium and for radionuclides such as 226Ra. These mineral-bound contaminants are considered immobilized under oxic conditions. However, when anoxic conditions develop, the activities of sulfate- or iron-reducing bacteria could result in mineral dissolution, releasing these bound contaminants. Reduction of structural sulfate in

  10. Copper-tantalum alloy

    DOEpatents

    Schmidt, Frederick A. (Ames, IA); Verhoeven, John D. (Ames, IA); Gibson, Edwin D. (Ames, IA)

    1986-07-15

    A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

  11. Copper associated childhood cirrhosis

    Microsoft Academic Search

    S P Horslen; M S Tanner; T D Lyon; G S Fell; M F Lowry

    1994-01-01

    Several papers have reported severe liver disease in association with massive hepatic copper accumulation, which do not seem to be either of the recognised copper associated liver diseases, namely Wilson's disease and Indian childhood cirrhosis. A further case is reported in which novel copper kinetic studies were carried out using the stable isotope 65Cu, showing that this patient did not

  12. Laser induced copper plating

    Microsoft Academic Search

    A. K. Al-Sufi; H. J. Eichler; J. Salk; H. J. Riedel

    1983-01-01

    Argon laser induced plating of copper spots and lines from copper sulfate solutions on glass and phenolic resin paper has been investigated. The substrates had to be precoated with an evaporated copper film. The highest plating rates have been obtained with a small film thickness of 25 nm. Spots with a thickness up to 30 ?m were plated.

  13. Role for copper in the cellular and regulatory effects of heme-hemopexin.

    PubMed

    Smith, Ann; Rish, Kimberly R; Lovelace, Rachel; Hackney, Jennifer F; Helston, Rachel M

    2009-06-01

    Hemopexin (HPX) binds heme tightly, thus protecting cells from heme toxicity during hemolysis, trauma and ischemia-reperfusion injury. Heme uptake via endocytosis of heme-HPX followed by heme catabolism by heme oxygenase-1 (HMOX1) raises regulatory iron pools, thus linking heme metabolism with that of iron. Normal iron homeostasis requires copper-replete cells. When heme-HPX induces HMOX1, the copper-storing metallothioneins (MTs) are also induced whereas the copper-responsive copper chaperone that delivers copper to Cu, Zn superoxide dismutase, CCS1, is decreased; both are known responses when cellular copper levels rise. Endocytosis of heme-HPX is needed to regulate CCS1 since the signaling ligand cobalt-protoporphyrin (CoPP)-HPX, which does not induce HMOX1 but does co-localize with heme-HPX in endosomes, also decreased CCS1. These observations support that heme-HPX mobilizes copper in cells. The regulation of both hmox1 and mt1 is prevented by the copper-chelator, bathocuproinedisulfonate (BCDS), but not uptake of heme-AlexaFluor-labeled HPX into endosomes. Supporting a role for copper in HMOX1 regulation by heme-HPX, nutritional copper deficiency generated by tetraethylene pentamine or 232 tetraamine prevented HMOX1 induction. Using conditions that mimic maturing endosomes, we found that copper prevents rebinding of heme to apo-HPX. A model is presented in which copper endocytosis together with that of heme-HPX provides a means to facilitate heme export from HPX in the maturing endosomes: heme is needed for hmox1 transcription, while cytosolic copper and CCS1 provide a link for the known simultaneous regulation of hmox1 and mt1 by heme-HPX. PMID:19039664

  14. Influence of high dietary iron as ferrous carbonate and ferrous sulfate on iron metabolism in young calves.

    PubMed

    McGuire, S O; Miller, W J; Gentry, R P; Neathery, M W; Ho, S Y; Blackmon, D M

    1985-10-01

    Twelve intact male Holstein calves averaging 90 kg and 12 wk of age were fed one of three dietary treatments for 28 d. The diets were A) control, B) control plus 1000 ppm iron as ferrous carbonate, and C) control plus 1000 ppm iron as ferrous sulfate monohydrate. Calves were dosed orally on d 15 of the treatment period with 1 mCi of iron-59. Neither source of added iron had a significant effect on weight gains, feed consumption, hemoglobin, packed cell volume, serum total iron, serum total iron-binding capacity, unbound iron-binding capacity, serum copper, tissue copper, fecal dry matter, or a consistent effect on fecal pH. The ferrous carbonate had no significant effect on stable zinc or stable iron in any tissue studied. Calves fed ferrous sulfate had higher average stable iron in most tissues and significantly more in the small intestine. Tissue zinc was lower in spleen and pancreas of ferrous sulfate-fed calves. Both sources of added iron sharply reduced iron-59 in serum, whole blood, and body tissues. The reduction was substantially greater in calves fed the ferrous sulfate iron. Iron in ferrous sulfate had a higher biological availability than that in the ferrous carbonate; however, bioavailability of the ferrous carbonate iron appeared to be substantial and considerably more than that noted in previous studies in which a different source of ferrous carbonate was used. The maximum safe level of dietary iron is materially influenced by the source of iron with a higher tolerance indicated for ferrous carbonated than ferrous sulfate monohydrate. PMID:4067037

  15. Copper pathways in Plasmodium falciparum infected erythrocytes indicate an efflux role for the copper P-ATPase.

    PubMed

    Rasoloson, Dominique; Shi, Lirong; Chong, Curtis R; Kafsack, Bjorn F; Sullivan, David J

    2004-08-01

    Copper, like iron, is a transition metal that can generate oxygen radicals by the Fenton reaction. The Plasmodium parasite invades an erythrocyte host cell containing 20 microM copper, of which 70% is contained in the Cu/Zn SOD (cuprozinc superoxide dismutase). In the present study, we follow the copper pathways in the Plasmodium-infected erythrocyte. Metal-determination analysis shows that the total copper content of Percoll-purified trophozoite-stage-infected erythrocytes is 66% that of uninfected erythrocytes. This decrease parallels the decrease seen in Cu/Zn SOD levels in parasite-infected erythrocytes. Neocuproine, an intracellular copper chelator, arrests parasites at the ring-to-trophozoite stage transition and also specifically decreases intraparasitic levels of Cu/Zn SOD and catalase. Up to 150 microM BCS (2,9-dimethyl-4,7-diphenyl-1,10-phenanthrolinedisulphonic acid), an extracellular copper chelator, has no effect on parasite growth. We characterized a single copy PfCuP-ATPase (Plasmodium falciparum copper P-ATPase) transporter, which, like the Crypto-sporidium parvum copper P-ATPase, has a single copper-binding domain: 'Met-Xaa-Cys-Xaa-Xaa-Cys'. Recombinant expression of the N-terminal metal-binding domain reveals that the protein specifically binds reduced copper. Transcription of the PfCuP-ATPase gene is the highest at late ring stage/early trophozoite, and is down-regulated in the presence of neocuproine. Immunofluorescence and electron microscopy indicate the transporter to be both in the parasite and on the erythrocyte membrane. Both the decrease in total copper and the location of the PfCuP-ATPase gene indicate a copper-efflux pathway from the infected erythrocyte. PMID:15125686

  16. HEALTH EFFECTS OF HUMAN EXPOSURE TO BARIUM IN DRINKING WATER

    EPA Science Inventory

    The overall objective of this study was to examine by epidemiologic and supportive laboratory studies, the human health effects associated with ingestion of barium in drinking water exceeding the U.S. drinking water standard of 1.0 mg/l. The incidence of cardiovascular mortality ...

  17. Barium strontium titanate powders prepared by spray pyrolysis

    Microsoft Academic Search

    G. Brankovi?; Z. Brankovi?; M. S. Góes; C. O. Paiva-Santos; M. Cilense; J. A. Varela; E. Longo

    2005-01-01

    Ultasonic spray pyrolysis (SP) has been investigated for the production of the barium strontium titanate (BST) powders from the polymeric precursors. The processing parameters, such as flux of aerosol and temperature profile inside the furnace, were optimized to obtain single phase BST. The powders were characterized by the methods of X-ray diffraction analysis, SEM, EDS and TEM. The obtained powders

  18. Original article Response to barium selenate supplementation in sheep

    E-print Network

    Boyer, Edmond

    group did not receive any supplement of Se and/or vitamin E. The two groups were managed under the sameOriginal article Response to barium selenate supplementation in sheep kept at pasture supplements in the prevention of dis- orders related to Se deficiency in sheep maintained at pasture

  19. REMOVING BARIUM AND RADIUM THROUGH CALCIUM CATION EXCHANGE

    EPA Science Inventory

    The removal of barium (Ba) and radium (Ra), which are found in many groundwater sources, was achieved in laboratory studies with an ion exchange process. In the studies, a strong acid resin in the calcium form effectively removed Ba(+2) and Ra (+2) to meet standards. The resin wa...

  20. BARIUM AND RADIUM REMOVAL FROM GROUNDWATER BY ION EXCHANGE

    EPA Science Inventory

    The primary objective of this study was to determine the applicability of weak acid exchange resin in the hydrogen form for removal of hardness, barium and radium from groundwater. Weak acid resin in the hydrogen form eliminates the addition of sodium to drinking water. The capac...

  1. PROPOSED ORAL REFERENCE DOSE (RFD) FOR BARIUM AND COMPOUNDS

    EPA Science Inventory

    The Integrated Risk Information System (IRIS) is a database of EPA's consensus opinion of the human health effects that may result from exposure to various substances found in the environment. A Toxicological Review and IRIS Summary were prepared for barium and compounds in 1998 ...

  2. Ultra-low temperature processing of barium tellurate dielectrics

    NASA Astrophysics Data System (ADS)

    Kwon, Do-Kyun

    Ceramics, metals and polymers have unique electrical properties that are combined for electronic devices and systems. It necessitates lower processing temperatures for ceramics to be compatible with metal and polymer systems. In this thesis, the synthesis, crystal structure, and dielectric properties of barium tellurate are studied for temperatures between 500 and 900°C. Barium tellurate dielectric ceramics (BaTe4O9, BaTe 2O5, BaTe2O6, BaTeO3, BaTeO 4, and Ba2TeO5) are extensively investigated as new LTCC (Low-Temperature Cofired Ceramics) dielectric systems integrated with low resistivity metal electrodes such as silver and aluminum for microwave application. Studies on the phase formation and crystal structure through thermal analyses (Differential Scanning Calorimetry and Thermogravimetric Analysis, DSC-TGA) and X-ray diffraction phase analysis attest that barium tellurates are formed in the temperature range of 500 ˜ 900°C, through the sequential phase formations from Te-rich to Ba-rich phases. The oxygen coordination of the tellurium ion progresses from TeO4 to TeO6 via TeO 3+1 and TeO3 with increasing barium content as confirmed by structural analysis using infrared spectroscopy. High density barium tellurate ceramics are achieved at temperatures as low as 550°C, which provides the potential to be co-fired with low-melting aluminum metal electrodes in LTCC processing. Dielectric permittivity, loss, and temperature stability of barium tellurate dielectric ceramics were measured from 100 Hz to 13 GHz. Barium tellurate ceramics exhibit excellent microwave dielectric properties with intermediate dielectric permittivities and high quality factors (Q). The dielectric properties at microwave frequencies are epsilonr = 17.5, Qxf = 54700 GHz, TCf = -90 ppm/°C for BaTe4O9, epsilonr = 21, Qxf = 50300 GHz, TCf = -51 ppm/°C for BaTe2O6, epsilonr = 10, Qxf = 34000 GHz, TCf = -54 ppm/°C for BaTeO3, and epsilonr = 17, Qx f = 49600 GHz, TCf = -124 ppm/°C for Ba 2TeO5. Co-firing studies of barium tellurate ceramics with metal electrodes establish new LTCC systems for microwave devices. Chemical compatibility of barium tellurates with silver electrodes was achieved in the barium rich compositions. Ba2TeO5 was found to be covetable with silver electrodes at 850°C by adding CuO and B2O3 as fluxing agents. During the co-firing, a thin interfacial layer of AgTe is metastable according to the thermodynamic equilibrium between the Ba2TeO5-Ag/Ag 2O pseudo-binary system. A breakthrough LTCC technology with aluminum is based upon the ultra-low processing temperature and chemical compatibility of BaTe4O 9, which enables co-firing and fabrication of multilayer ceramic capacitors (MLCCs) with aluminum inner electrodes. The aluminum base metal electrode (BME) BaTe4O9 MLCCs provide good dielectric properties of epsilonr = 17.5, TCepsilon = 100 ppm/°C, and tan delta = 2.1 x 10-3 (Q ? 500) at 1 MHz, which are suitable for the class-1 MLCCs. Aluminum microstrip ring resonators on the BaTe4O9 substrates realized good electromagnetic performance of the new materials at microwave frequency exhibiting resonant frequency of 2.97 GHz and Q factor of 278.

  3. Improvement of the technology of iron removal from electrolyte solutions in nonferrous Metallurgy

    NASA Astrophysics Data System (ADS)

    Motov, D. L.; Vasekha, M. V.

    2009-12-01

    An improved variant for the purification of a nickel electrolyte from iron has been developed. According to the flow chart proposed for purification, copper is first extracted by carburization with nickel and iron hydroxide then precipitates upon the introduction of nickel carbonate and oxidation with air oxygen. The iron hydroxide is subjected to conversion into ferrisulfite with the thermal hydrolysis of a suspension and the filtration and washing of the hydrolyzate and to heat treatment to obtain pigment iron(III) oxide.

  4. Dielectric characteristics of barium strontium titanate films prepared by aerosol deposition on a Cu substrate.

    PubMed

    Oh, Sewoong; Park, Jae-Hyuk; Akedo, Jun

    2009-03-01

    Polycrystalline barium strontium titanate (Ba(x)Sr(1-x)TiO(3), BST) films were directly prepared on copper substrates using an aerosol deposition method (ADM) at room temperature. Electric properties, such as the dielectric constant and tunability, were investigated as a function of the Ba content in Ba(x)Sr(1-x)TiO(3) (x = 1.0, 0.6, 0.4) films. At a frequency of 100 kHz, the dielectric constant of the as-deposited BST films were 100, 201, and 72 for x = 1.0, 0.6, and 0.4, respectively. After annealing in N(2) ambient at 500 degrees C, the dielectric constant of the films on Cu electrodes were 190, 400, and 170 at x = 1.0, 0.6, and 0.4, respectively. Moreover, the BST (x = 0.6) film showed a high tunability of 30% under an applied electric field of 300 kV cm(-1). PMID:19411201

  5. Flux Pinning and Critical Current Densities in Proton Irradiated Single Crystal Yttrium Barium Copper Oxide

    Microsoft Academic Search

    Hema Krishnan Viswanathan

    1994-01-01

    Radiation damage has been traditionally used to introduce artificial pinning centers into superconducting material in order to enhance their critical current densities. The objective of this study was to determine the effect of defects induced by irradiation with 3.5 MeV protons on the critical current densities and to investigate the structure of the defects using SQUID magnetization and magnetoresistive measurements.

  6. A scanning tunneling microscopy investigation of yttrium barium(2) copper(3) oxygen(7-x)

    Microsoft Academic Search

    David Joseph Derro

    2000-01-01

    Single crystals of the high temperature superconductor YBa2Cu 3O7-x were investigated with an ultra-high vacuum, low-temperature scanning tunneling microscope. Detailed microscopy and spectroscopy of the CuO chain plane were obtained after cleaving the sample in situ and imaging at 4 K. The microscopy reveals a surface rich with structural details including atomically resolved CuO chains with an overlying charge modulation

  7. Magnetic Anisotropy in the High Transition Temperature Superconductor Yttrium BARIUM(2) COPPER(3) OXYGEN(7DELTA)

    Microsoft Academic Search

    Ado Umezawa

    1991-01-01

    The strong anisotropy found in the electronic structure of YBa_2Cu_3 O_{7-delta} resulting from the existence of both the CuO_2 planes within the a,b plane and the CuO chains along the b axis has brought strong interest regarding the effect of the electronic structure anisotropy on the superconducting properties in this material. Such superconducting properties include both the intrinsic type (such

  8. Highly-textured thallium-barium-calcium-copper-oxide polycrystalline superconducting films on silver substrates

    SciTech Connect

    Arendt, P.; Elliott, N.; Cooke, D.W.; Dye, R.; Gray, E.; Hubbard, K.; Martin, J.; Reeves, G.; Brown, D.; Klapetzky, A.

    1990-01-01

    Thick (8 to 10 {mu}m) Ba--Ca--Cu--O films have been rf magnetron sputtered onto Ag alloy (Consil 995) substrates. The films were given a post-deposition anneal in an over pressure of Tl in order to form the superconducting phases. Annealing protocols were done which result in predominantly the 1212 and 2212 phases. The substrate orientation was varied to determine its effect on film orientation. Material properties of the films were characterized by x-ray diffraction (XRD), ion beam backscattering spectroscopy, energy dispersive x-ray analysis (EDAX), and scanning electron microscopy (SEM). Electrical characterization of the films was done using dynamic impedance (DI) at 10 kHz and rf surface resistance (R{sub s}) at 18 GHz in a TE{sub 011} fundamental mode cavity. 19 refs., 7 figs.

  9. Microwave Properties of Yttrium BARIUM(2) COPPER(3) OXYGEN(7-X)/INSULATOR Heterostructures

    NASA Astrophysics Data System (ADS)

    Findikoglu, Alp Tugrul

    The purpose of the work presented in this dissertation is not only to provide detailed information about the electrodynamic properties of high-T_{c} superconductors but also to assess their potential for technological applications at microwave frequencies. This work adopts a device approach to investigate the microwave properties of high-T_{c} thin films and high-T_{c}/insulator heterostructures, concentrating equally on issues relating to materials, physics, and device technology. Microwave measurements on YBa_2 Cu_3O_{ 7-x} (YBCO) films patterned into meander lines show that the electrodynamic properties of these films are significantly different from those of conventional superconductors such as Nb, but they nevertheless exhibit much lower microwave loss than normal metals such as Cu at low temperatures (<80 K). Dielectric resonator measurements on the YBCO/insulator heterostructures indicate that sample preparation conditions and the geometry of the sample structure have a significant effect on the microwave response. Samples with well-oxygenated layers and clean interfaces behave as predicted by simple models. A detailed study of the dc electric field effect on the microwave response of these heterostructures shows that field modulated changes in both the complex conductivity of the YBCO layers (superconducting hole filling and depletion) and the dielectric properties of the insulating layers (electric field dependence of the dielectric constant) contribute to the overall microwave response.

  10. Hall Effect Studies in THALLIUM(2) BARIUM(2) Copper OXYGEN(6 + Delta)

    NASA Astrophysics Data System (ADS)

    Tello, Rafael Federico

    The two independent components of the Hall coefficient were measured as a function of temperature and oxygen doping for Tl-2201 single crystals by means of a double frequency ac technique. The carriers are found to be positive for the R^{H}_{abc } component and positive or negative for R^{H}_{cab} depending on the doping. In the optimally doped samples the inverse Hall mobility for R^ {H}_{abc} is found to deviate from the expected T^2 behavior. The inverse Hall mobility is found to be temperature independent for the R^{H}_ {cab} component.

  11. Physical Properties of Oxygen Deficient YTTRIUM(1) BARIUM(2) COPPER(3) OXYGEN(7-DELTA) Superconductors.

    NASA Astrophysics Data System (ADS)

    Sun, He Bi.

    The physical properties of oxygen deficient polycrystalline rm YBa_2Cu_3O_{7 -delta} superconducting materials have been systematically investigated. These properties include magnetic susceptibility, electrical transport, thermoelectric power and infrared reflectivity. A great deal of this study has concentrated on the magnetic and transport properties of these materials when they are in the mixed state. The polycrystalline specimens used in this work were prepared through a solid state reaction. The oxygen content of the specimens was controlled using several annealing methods and the oxygen deficiency delta was determined by X-ray diffraction, gas evolution, iodometric titration and neutron diffraction techniques. A new method has been developed for the investigation of magnetic relaxation in these materials using the conventional a.c. susceptibility technique after modification. This thesis represents the first detailed and systematic study of the thermal activation energy for high Tc superconductors using many different methods, including a.c. susceptibility, magnetic relaxation, electric resistivity and thermoelectric power. All the results obtained, including their numerical values and field dependence are consistent with and comparable to previously reported data. A modified critical state model has been successfully used to interpret the magnetic field dependence of the isothermal a.c. susceptibility data, including field dependent a.c. losses and the chi^' -chi^{'' } interrelationship. This study highlights the strong influence that delta exerts on the superconducting and normal state properties of polycrystalline rm YBa_2Cu_3O_{7-delta } material. In particular, for transport properties, delta affects the carrier doping in the CuO_2 planes, which determines the carrier concentration. Therefore increasing delta reduces the superconducting transition temperature. For the magnetic property, delta has a negative influence on the pinning energy in polycrystalline material and therefore reduces the critical current density. The infrared reflectivity spectra and extracted dielectric function show a dramatic change in the longitudinal and transverse mode structure of these materials which occurs when oxygen is removed from the chain sites.

  12. Penetration Depth Studies in Nickel and Zinc Doped Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA)

    NASA Astrophysics Data System (ADS)

    Ulm, Eric R.

    1995-01-01

    Many recent experiments have supported the hypothesis of d-wave superconductivity in the high-T_ {c} superconductors. Measurements of lambda(T), the magnetic field penetration depth, have given some of the best evidence for d-wave superconductivity in YBa_2Cu _3O_{7-delta} . This thesis reports measurements of lambda(T) in pure, Ni and Zn-doped YBa _2Cu_3O_ {7-delta} films by measuring the change in the mutual inductance of two coils on opposite sides of the films. The low-temperature linear dependence of lambda(T) at low temperatures in YBa_2Cu_3O _{7-delta} and rapid increase in lambda(0) with doping support the hypothesis of d-wave superconductivity and are inconsistent with the predictions of s-wave models. Alternative explanations for the linear lambda(T) have been proposed in terms of fluctuations in the phase of the order parameter. These fluctuations should be more pronounced in films with large values of lambda (0). We find that the linear term actually disappears in films with large lambda(0), showing that phase fluctuations are not responsible for the linear behavior observed in YBa_2Cu _3O_{7-delta} .

  13. Method of producing highly oxidized superconductors containing barium, copper, and a third metal

    DOEpatents

    Morris, Donald E. (Kensington, CA)

    1996-01-01

    Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed.

  14. Transport and infrared properties of ion irradiated yttrium barium copper oxide thin films

    Microsoft Academic Search

    Steven H. Moffat

    1997-01-01

    The discovery of high temperature superconductors prompted the reconsideration of numerous aspects of superconductivity. Among the most fundamental and controversial is the origin of dissipation in a current carrying superconductor. This is also very important from an applied perspective since the onset of dissipation, often described by the critical current density Jsb{C}, determines the current carrying capacity of a material.

  15. Electrodeposition and Characterization of Yttrium Barium Copper Oxide Superconducting Thin Films

    NASA Astrophysics Data System (ADS)

    Weston, Alan James

    Precursor thin films of Y-Ba-Cu-O superconductor were produced by potentiostatic and pulse electrodeposition from the dissolved nitrate salts of Y, Ba, Cu in dimethylformamide (DMF). The films were deposited on metal foils such as Ag-coated Cu, Ag, Ni, and Zr. Films were also synthesized on Ag-coated SrTiO_3, CaTiO _3, and Al_2O _3. The electrodeposited films were heat treated in flowing O_2 in order to produce the superconducting phase. The film composition as a function of the salt concentration in DMF was determined by energy dispersive x-ray analysis. Surface compositions were obtained by Auger electron spectroscopy. Crystal structure and phases were identified by means of x-ray diffraction. The superconducting dimagnetic behaviour has been observed in magnetic measurements. Films formed by pulse plating on the titanates and on Zr exhibited the best uniformity with highest T_{rm c}. Y-Ba-Cu-O films formed on Zr had highest T_{rm c} onset at 93 K (resistance measurement). The pulse plating process was extended to the synthesis of Er-Ba-Cu-O films. On Zr, the latter resulted in a T_{rm c} onset at 80 K.

  16. Preparation and Microstructural Characterization of Yttrium Barium Copper Oxygen Superconducting Thin Films

    Microsoft Academic Search

    Muzeyyen Ece

    1990-01-01

    The preparation and microstructural characterization of YBaCuO superconducting thin films are described. The films were deposited onto various substrates by flash evaporation and rf magnetron sputtering methods. The flash evaporation was made by dropping powders of sintered Y_1Ba_2Cu _3O_{rm 7-x} onto a resistively heated W boat. A sintered powder target was used for the rf magnetron sputtering. In the latter

  17. Fabrication and characterization of yttrium barium copper oxide superconductors for microwave applications

    NASA Astrophysics Data System (ADS)

    Basarab, Douglas J.; Dornath-Mohr, Michelle A.; Eckart, Donald W.; Finnegan, Robert D.; Klimek, Joseph P.

    1991-01-01

    High temperature superconductors offer several advantages over normal conductors for low power device applications. Bulk ceramic processing parameters are investigated to define optimum conditions for materials useful in microwave applications. Calcining, sintering, and reaction atmosphere were systematically varied in bulk samples. The density, microstructure and composition, dc resistivity, microwave Q, and surface resistivity were followed as a function of sintering temperature. An optimum sintering temperature is defined.

  18. Arrays of membrane isolated yttrium-barium-copper-oxide kinetic inductance bolometers

    NASA Astrophysics Data System (ADS)

    Lindeman, M. A.; Bonetti, J. A.; Bumble, B.; Day, P. K.; Eom, B. H.; Holmes, W. A.; Kleinsasser, A. W.

    2014-06-01

    We are developing of arrays of membrane isolated resonator-bolometers, each with a kinetic inductance device (KID) to measure the temperature of the membrane. The KIDs are fabricated out of the high temperature superconductor YBCO to allow operation at relatively high temperatures. The bolometers are designed to offer higher sensitivity than sensors operating at 300 K, but they require less expensive and lighter weight cooling than even more sensitive conventional superconducting detectors operating at lower temperatures. The bolometer arrays are applicable as focal planes in infrared imaging spectrometers, such as for planetary science missions or earth observing satellites. We describe the devices and present measurements of their sensitivity.

  19. Scanning Hall Probe Microscopy of Magnetic Vortices inVery Underdoped yttrium-barium-copper-oxide

    SciTech Connect

    Guikema, Janice Wynn; /SLAC, SSRL

    2005-12-02

    Since their discovery by Bednorz and Mueller (1986), high-temperature cuprate superconductors have been the subject of intense experimental research and theoretical work. Despite this large-scale effort, agreement on the mechanism of high-T{sub c} has not been reached. Many theories make their strongest predictions for underdoped superconductors with very low superfluid density n{sub s}/m*. For this dissertation I implemented a scanning Hall probe microscope and used it to study magnetic vortices in newly available single crystals of very underdoped YBa{sub 2}Cu{sub 3}O{sub 6+x} (Liang et al. 1998, 2002). These studies have disproved a promising theory of spin-charge separation, measured the apparent vortex size (an upper bound on the penetration depth {lambda}{sub ab}), and revealed an intriguing phenomenon of ''split'' vortices. Scanning Hall probe microscopy is a non-invasive and direct method for magnetic field imaging. It is one of the few techniques capable of submicron spatial resolution coupled with sub-{Phi}{sub 0} (flux quantum) sensitivity, and it operates over a wide temperature range. Chapter 2 introduces the variable temperature scanning microscope and discusses the scanning Hall probe set-up and scanner characterizations. Chapter 3 details my fabrication of submicron GaAs/AlGaAs Hall probes and discusses noise studies for a range of probe sizes, which suggest that sub-100 nm probes could be made without compromising flux sensitivity. The subsequent chapters detail scanning Hall probe (and SQUID) microscopy studies of very underdoped YBa{sub 2}Cu{sub 3}O{sub 6+x} crystals with T{sub c} {le} 15 K. Chapter 4 describes two experimental tests for visons, essential excitations of a spin-charge separation theory proposed by Senthil and Fisher (2000, 2001b). We searched for predicted hc/e vortices (Wynn et al. 2001) and a vortex memory effect (Bonn et al. 2001) with null results, placing upper bounds on the vison energy inconsistent with the theory. Chapter 5 discusses imaging of isolated vortices as a function of T{sub c}. Vortex images were fit with theoretical magnetic field profiles in order to extract the apparent vortex size. The data for the lowest T{sub c}'s (5 and 6.5 K) show some inhomogeneity and suggest that {lambda}{sub ab} might be larger than predicted by the T{sub c} {proportional_to} n{sub s}(0)/m* relation first suggested by results of Uemura et al. (1989) for underdoped cuprates. Finally, Chapter 6 examines observations of apparent ''partial vortices'' in the crystals. My studies of these features indicate that they are likely split pancake vortex stacks. Qualitatively, these split stacks reveal information about pinning and anisotropy in the samples. Collectively these magnetic imaging studies deepen our knowledge of cuprate superconductivity, especially in the important regime of low superfluid density.

  20. COPPER DEFICIENCY PROPHYLAXIS IN GRAZING SHEEP BY COPPER OXIDE INJECTION

    E-print Network

    Boyer, Edmond

    COPPER DEFICIENCY PROPHYLAXIS IN GRAZING SHEEP BY COPPER OXIDE INJECTION M. LAMAND Claudine LAB R of insoluble and non ionized form of injected copper has been shown in a previous paper (Lamand, 1978 it appeared that copper oxide was preferable to metallic copper, being slightly less caustic. Inflammation

  1. Bacterial iron homeostasis

    Microsoft Academic Search

    Simon C Andrews; Andrea K Robinson; Francisco Rodr??guez-Quiñones

    2003-01-01

    Iron is essential to virtually all organisms, but poses problems of toxicity and poor solubility. Bacteria have evolved various mechanisms to counter the problems imposed by their iron dependence, allowing them to achieve effective iron homeostasis under a range of iron regimes. Highly efficient iron acquisition systems are used to scavenge iron from the environment under iron-restricted conditions. In many

  2. Surface studies of barium and barium oxide on tungsten and its application to understanding the mechanism of operation of an impregnated tungsten cathode

    NASA Technical Reports Server (NTRS)

    Forman, R.

    1976-01-01

    Surface studies have been made of multilayer and monolayer films of barium and barium oxide on a tungsten substrate. The purpose of the investigation was to synthesize the surface conditions that exist on an activated impregnated tungsten cathode and obtain a better understanding of the mechanism of operation of such cathodes. The techniques employed in these measurements were Auger spectroscopy and work-function measurements. The results of this study show that the surface of an impregnated cathode is identical to that observed for a synthesized monolayer or partial monolayer of barium on oxidized tungsten by evaluating Auger spectra and work-function measurements. Data obtained from desorption studies of barium monolayers on a tungsten substrate in conjunction with Auger and work-function results have been interpreted to show that throughout most of its life an impreganated cathode has a partial monolayer, rather than a monolayer, of barium on its surface.

  3. Method and apparatus for storing hydrogen isotopes. [stored as uranium hydride in a block of copper

    DOEpatents

    McMullen, J.W.; Wheeler, M.G.; Cullingford, H.S.; Sherman, R.H.

    1982-08-10

    An improved method and apparatus for storing isotopes of hydrogen (especially tritium) are provided. The hydrogen gas is stored as hydrides of material (for example uranium) within boreholes in a block of copper. The mass of the block is critically important to the operation, as is the selection of copper, because no cooling pipes are used. Because no cooling pipes are used, there can be no failure due to cooling pipes. And because copper is used instead of stainless steel, a significantly higher temperature can be reached before the eutectic formation of uranium with copper occurs, (the eutectic of uranium with the iron in stainless steel forms at a significantly lower temperature).

  4. Increased iron supplied through Fet3p results in replicative life span extension of Saccharomyces cerevisiae under conditions requiring respiratory metabolism

    Microsoft Academic Search

    Gabriela Botta; Christina S. Turn; Nicholas J. Quintyne; Paul A. Kirchman

    2011-01-01

    We have previously shown that copper supplementation extends the replicative life span of Saccharomyces cerevisiae when grown under conditions forcing cells to respire. We now show that copper's effect on life span is through Fet3p, a copper containing enzyme responsible for high affinity transport of iron into yeast cells. Life span extensions can also be obtained by supplementing the growth

  5. Current perspectives in colon radiography: the postendoscopy and postbiopsy barium enema.

    PubMed

    Lappas, J C; Maglinte, D D

    1985-01-01

    Controversy prevails regarding the same-day performance of barium enema examinations and endoscopy. Concerns focus upon the diagnostic quality of the postendoscopy barium enema and the risk of perforation if colorectal biopsy is performed during the endoscopy. Results of a study of 295 patients support that rigid or fiberoptic sigmoidoscopy can be performed the same day as single- or double-contrast barium enemas without adversely affecting the quality or interpretation of the barium examination. Animal studies suggest that a barium enema may be performed safely immediately after a superficial biopsy of a nondiseased colon and 6 days after a deep biopsy. Barium sulfate appears to have no deleterious effect on the healing of colorectal biopsy sites. These findings have important implications when considering health care logistics and cost containment. PMID:3896653

  6. NASA/Max Planck Institute Barium Ion Cloud Project.

    NASA Technical Reports Server (NTRS)

    Brence, W. A.; Carr, R. E.; Gerlach, J. C.; Neuss, H.

    1973-01-01

    NASA and the Max Planck Institute for Extraterrestrial Physics (MPE), Munich, Germany, conducted a cooperative experiment involving the release and study of a barium cloud at 31,500 km altitude near the equatorial plane. The release was made near local magnetic midnight on Sept. 21, 1971. The MPE-built spacecraft contained a canister of 16 kg of Ba CuO mixture, a two-axis magnetometer, and other payload instrumentation. The objectives of the experiment were to investigate the interaction of the ionized barium cloud with the ambient medium and to deduce the properties of electric fields in the proximity of the release. An overview of the project is given to briefly summarize the organization, responsibilities, objectives, instrumentation, and operational aspects of the project.

  7. The Skylab barium plasma injection experiments. I - Convection observations

    NASA Technical Reports Server (NTRS)

    Wescott, E. M.; Stenbaek-Nielsen, H. C.; Davis, T. N.; Peek, H. M.

    1976-01-01

    Two barium-plasma injection experiments were carried out during magnetically active periods in conjunction with the Skylab 3 mission. The high-explosive shaped charges were launched near dawn on November 27 and December 4, 1973, UT. In both cases, the AE index was near 400 gammas, and extensive pulsating auroras covered the sky. The first experiment, Skylab Alpha, occurred in the waning phase of a 1000-gamma substorm, and the second, Skylab Beta, occurred in the expansive phase of an 800-gamma substorm. In both, the convection was generally magnetically eastward, with 100-km-level electric fields near 40 mV/m. However, in the Alpha experiment the observed orientation of the barium flux tube fit theoretical field lines having no parallel current, but the Beta flux-tube orientation indicated a substantial upward parallel sheet current.

  8. Preparation of a metalorganic deposition precursor for barium titanate

    SciTech Connect

    Apblett, A.W.; Georgieva, G.D.; Raygoza-Maceda, I. [Tulane Univ., New Orleans, LA (United States)

    1994-12-31

    A new, facile preparative route for BaTiO(Ox){sub 2} has been developed (Ox=oxalate). This involves passing a solution of K{sub 2}TiO(Ox){sub 2} through an ion-exchange resin to convert it to the proteo-derivative, H{sub 2}TiO(Ox){sub 2}. Treatment of the latter with BaCl{sub 2} results in precipitation of BaTiO(Ox){sub 2} with a ratio of barium:titanium of 1:1.009. Finally, reaction of BaTiO(Ox){sub 2} with refluxing methoxyacetic acid produces an alcohol and chlorocarbon soluble ceramic precursor that may be used to prepare thin films of barium titanate by metalorganic deposition.

  9. Dielectric function for doped graphene layer with barium titanate

    NASA Astrophysics Data System (ADS)

    Martinez Ramos, Manuel; Garces Garcia, Eric; Magana, Fernado; Vazquez Fonseca, Gerardo Jorge

    2015-03-01

    The aim of our study is to calculate the dielectric function for a system formed with a graphene layer doped with barium titanate. Density functional theory, within the local density approximation, plane-waves and pseudopotentials scheme as implemented in Quantum Espresso suite of programs was used. We considered 128 carbon atoms with a barium titanate cluster of 11 molecules as unit cell with periodic conditions. The geometry optimization is achieved. Optimization of structural configuration is performed by relaxation of all atomic positions to minimize their total energies. Band structure, density of states and linear optical response (the imaginary part of dielectric tensor) were calculated. We thank Dirección General de Asuntos del Personal Académico de la Universidad Nacional Autónoma de México, partial financial support by Grant IN-106514 and we also thank Miztli Super-Computing center the technical assistance.

  10. Biogenic nanoparticles: copper, copper oxides, copper sulphides, complex copper nanostructures and their applications.

    PubMed

    Rubilar, Olga; Rai, Mahendra; Tortella, Gonzalo; Diez, Maria Cristina; Seabra, Amedea B; Durán, Nelson

    2013-09-01

    Copper nanoparticles have been the focus of intensive study due to their potential applications in diverse fields including biomedicine, electronics, and optics. Copper-based nanostructured materials have been used in conductive films, lubrification, nanofluids, catalysis, and also as potent antimicrobial agent. The biogenic synthesis of metallic nanostructured nanoparticles is considered to be a green and eco-friendly technology since neither harmful chemicals nor high temperatures are involved in the process. The present review discusses the synthesis of copper nanostructured nanoparticles by bacteria, fungi, and plant extracts, showing that biogenic synthesis is an economically feasible, simple and non-polluting process. Applications for biogenic copper nanoparticles are also discussed. PMID:23690046

  11. Synthesis of barium titanate films by plasma electrolytic oxidation at room electrolyte temperature

    Microsoft Academic Search

    Chu-Tsun Wu; Fu-Hsing Lu

    2005-01-01

    Crystalline barium titanate films were directly synthesized onto Ti plates by plasma electrolytic oxidation at room temperature using barium acetate and 2 M NaOH as electrolytes. The effect of the concentration of barium acetate ranging from 0.05 M to 0.5 M on the synthesis of BaTiO3 was investigated. XRD results showed that the formation of BaTiO3 required a minimum of

  12. The positive temperature coefficient of resistivity in barium titanate

    Microsoft Academic Search

    B. Huybrechts; K. Ishizaki; M. Takata

    1995-01-01

    Positive temperature coefficient of resistivity (PTCR) materials have become very important components, and among these materials\\u000a barium titanate compounds make up the most important group. When properly processed these compounds show a high PTCR at the\\u000a Curie temperature (the transition temperature from the ferroelectric tetragonal phase to the paraelectric cube phase). In\\u000a the first half of this paper literature related

  13. Isotopic Masses of Hydrogen, Chlorine, Barium, Cerium, and Neodymium

    Microsoft Academic Search

    Jay L. Benson; Walter H. Johnson

    1966-01-01

    The 16-in. double-focusing mass spectrometer at the University of Minnesota has been employed to measure the atomic mass of H1 and the atomic masses and isotopic mass differences of chlorine, barium, cerium, and neodymium. Recent improvements in instrumentation have increased the precision of both narrow and wide doublet measurements. The doublet C11H22-C12H10 was used to relate the H1 mass directly

  14. Elastic and Piezoelectric Coefficients of Single-Crystal Barium Titanate

    Microsoft Academic Search

    Don Berlincourt; Hans Jaffe

    1958-01-01

    Mechanical resonance and antiresonance frequencies were measured on barium titanate single-crystal elements maintained under electric dc bias from -50°C to +150°C. A complete set of elastic, piezoelectric, and dielectric constants of the tetragonal modification at 25°C is obtained. The elastic compliances show substantial deviation from cubic symmetry. Measurements in the orthorhombic state show longitudinal compliance four times higher than in

  15. Luminescence of re 2+ (re = Sm, Yb) in barium octoborate

    Microsoft Academic Search

    Qinghua Zeng; Zhiwu Pei; Shubing Wang; Qiang Su; Shaozhe Lu

    1999-01-01

    The reduction process from trivalent to divalent state for Sm3+ and Yb3+ ions in barium borates (BaB8O13) prepared in air was observed. The luminescence properties of these divalent rare-earth ions were studied. Yb2+ shows an f-d broad emission band, due to the 4f14 ? 4f135d transition, while the Sm2+ ion shows an f ? f transition. From the spectra of

  16. Anomalous permittivity in fine-grain barium titanate

    Microsoft Academic Search

    Steven Paul Ostrander

    1997-01-01

    Fine-grain barium titanate capacitors exhibit anomalously large permittivity. It is often observed that these materials will double or quadruple the room temperature permittivity of a coarse-grain counterpart. However, aside from a general consensus on this permittivity enhancement, the properties of the fine-grain material are poorly understood. This thesis examines the effect of grain size on dielectric properties of a self-consistent

  17. High adherence copper plating process

    DOEpatents

    Nignardot, Henry (Tesuque, NM)

    1993-01-01

    A process for applying copper to a substrate of aluminum or steel by electrodeposition and for preparing an aluminum or steel substrate for electrodeposition of copper. Practice of the invention provides good adhesion of the copper layer to the substrate.

  18. Barium as a potential indicator of phosphorus in agricultural runoff.

    PubMed

    Ahlgren, Joakim; Djodjic, Faruk; Wallin, Mats

    2012-01-01

    In many catchments, anthropogenic input of contaminants, and in particular phosphorus (P), into surface water is a mixture of agricultural and sewage runoff. Knowledge about the relative contribution from each of these sources is vital for mitigation of major environmental problems such as eutrophication. In this study, we investigated whether the distribution of trace elements in surface waters can be used to trace the contamination source. Water from three groups of streams was investigated: streams influenced only by agricultural runoff, streams influenced mainly by sewage runoff, and reference streams. Samples were collected at different flow regimes and times of year and analyzed for 62 elements using ICP-MS. Our results show that there are significant differences between the anthropogenic sources affecting the streams in terms of total element composition and individual elements, indicating that the method has the potential to trace anthropogenic impact on surface waters. The elements that show significant differences between sources are strontium (p < 0.001), calcium (p < 0.004), potassium (p < 0.001), magnesium (p < 0.001), boron (p < 0.001), rhodium (p = 0.001), and barium (p < 0.001). According to this study, barium shows the greatest potential as a tracer for an individual source of anthropogenic input to surface waters. We observed a strong relationship between barium and total P in the investigated samples (R(2) = 0.78), which could potentially be used to apportion anthropogenic sources of P and thereby facilitate targeting of mitigation practices. PMID:22218189

  19. Toward remote ion-ion entanglement with barium

    NASA Astrophysics Data System (ADS)

    Noel, Thomas W.; Auchter, Carolyn; Chou, Chen-Kuan; Blinov, Boris B.

    2015-03-01

    We present work toward remote entanglement of barium ions in traps separated by a few meters. A new version of an ion trap specialized for remote entanglement is introduced. The new trap allows for highly efficient collection of ion fluorescence while simultaneously minimizing ion micromotion and aligning the trap position precisely to the focus of an in-vacuum parabolic mirror by using a set of bias electrodes and a piezoelectric micro-positioning system. The success rate of the remote entanglement procedure depends strongly on the efficiency with which ion fluorescence can be coupled into an optical fiber. Characterization of our system in terms of ion fluorescence collection and fiber coupling efficiency is presented. Results demonstrating entanglement between a single barium ion and single spontaneously emitted photons are shown. The entanglement fidelity of the ion-photon state is measured to be 0.84(1) and a CHSH Bell signal of 2.303(36) finds violation of the CHSH version of the Bell inequality by over eight standard deviations. Barium's relatively long wavelength transitions make it an ideal candidate for our longer term goal of remote entanglement of ions separated by a kilometer or more. Such long distance remote entanglement should allow for a loophole-free verification of the violation of the Bell inequality.

  20. Structural properties of barium strontium titanate films grown under different technological conditions

    NASA Astrophysics Data System (ADS)

    Tumarkin, A. V.; Al'myashev, V. I.; Razumov, S. V.; Gaidukov, M. M.; Gagarin, A. G.; Altynnikov, A. G.; Kozyrev, A. B.

    2015-03-01

    The structural properties of ferroelectric barium strontium titanate films with different compositions prepared under different deposition conditions have been investigated. It has been shown that the deposition temperature directly affects the phase and component compositions of the films, crystal lattice parameters, and crystallite sizes. At a deposition temperature of approximately 600°C, impurity phases of strontium polytitanates are formed in addition to the barium strontium titanate phase. An increase in the deposition temperature to 880°C leads to a barium deficiency as compared to the sputtering target. The deposition temperature providing a stoichiometric transfer of the component composition of the target into the barium strontium titanate film has been estimated.

  1. Innovation of a New-Style Macromolecule Compound Flocculant and its Application for Treating Copper Heavy Metal Wastewater

    Microsoft Academic Search

    Cui Yan; Wu Chao; Wang Haining; Feng Xiujuan

    2009-01-01

    The copper heavy metal wastewater does lots of harm to people and it is difficult to deal. Using flocculant to treat copper wastewater has a lot of advantages. Under certain conditions proceeded modification of a kind of clay which has the unique characteristic of absorbability. Then the modification clay and the polymerization iron carbonyl ion can play polyreaction, to innovate

  2. The Application of Electrochemical and Surface Analysis Approaches to Studying Copper Corrosion in Water: Fundamentals, Limitations, and Examples

    EPA Science Inventory

    Corrosion control is a concern for many drinking water utilities. The Lead and Copper Rule established a regulatory need to maintain a corrosion control program. Other corrosion-related issues such as ?red? water resulting from excessive iron corrosion and copper pinhole leaks ...

  3. Copper-containing zeolite catalysts

    DOEpatents

    Price, Geoffrey L. (Baton Rouge, LA); Kanazirev, Vladislav (Sofia, BG)

    1996-01-01

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl.sub.2, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  4. Copper-containing zeolite catalysts

    DOEpatents

    Price, G.L.; Kanazirev, V.

    1996-12-10

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, is formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl{sub 2}, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  5. A cap-type Schiff base acting as a fluorescence sensor for zinc(II) and a colorimetric sensor for iron(II), copper(II), and zinc(II) in aqueous media.

    PubMed

    Kim, Kyung Beom; Kim, Hyun; Song, Eun Joo; Kim, Sumi; Noh, Insup; Kim, Cheal

    2013-12-21

    A simple and low cost chemosensor is described. This sensor could simultaneously detect three biologically important metal ions through fluorogenic (Zn(2+)) and chromogenic (Fe(2+), Cu(2+), and Zn(2+)) methods in aqueous solution. The sensor could function as a "turn-on" fluorescence receptor only to Zn(2+) ions. In addition, the sensor could be successfully applied to the detection of intracellular Zn(2+). Meanwhile, the sensor displayed an obvious red color upon selective binding with Fe(2+). Therefore, the sensor could serve as a useful tool for the discrimination of Fe(2+) from Fe(3+) in aqueous media. Moreover, the sensor also showed color changes from yellow to colorless upon selective binding with Zn(2+) and Cu(2+), respectively. The detection limit of the sensor for Cu(2+) (1.5 ?M) is far below the guidelines of the World Health Organization (30 ?M) as the maximum allowable copper concentration in drinking water, and therefore it is capable of being a practical system for the monitoring of Cu(2+) concentrations in aqueous samples. These results provide a new approach for selectively recognizing the most important three trace elements in the human body simultaneously, for Zn(2+) by emission spectra and Fe(2+), Cu(2+), and Zn(2+) by the naked eye. PMID:24067938

  6. Influence of citric acid on the morphology and magnetic properties of barium ferrite thin films

    NASA Astrophysics Data System (ADS)

    Zhang, Wanli; Tang, Hao; Peng, Bin; Zhang, Wenxu

    2010-10-01

    Hexagonal barium ferrite (BaFe 12O 19) thin films were fabricated by spin coating of precursors from sol-gel methods. Different amount of citric acid was added. Weight loss and changes of chemical bonds during the heat treatment below 500 °C were recorded by thermogravity analyzer and Fourier transform infrared spectroscopy, respectively. The morphology of the films, i.e. the amount of acicular crystallites in the film, was controlled by adjusting the quantity of citric acid. The X-ray diffraction shows that the films are c-axis oriented, but the crystallization is less perfect with the increase of the citric acid. With the increase of the citric acid, the percentage of the acicular crystallites increased. At the same time, the coercivity force increased. The acicular crystallites were not exchange-coupled to the platelet crystallites. The citric acid was understood to form complex with iron ions and accelerate the exothermal auto-combustion. The c-axis oriented growth of the film was thus deteriorated.

  7. Chemical compositions of four barium stars

    NASA Astrophysics Data System (ADS)

    Liang, Y. C.; Zhao, G.; Chen, Y. Q.; Qiu, H. M.; Zhang, B.

    2003-01-01

    We obtain abundances of alpha , iron peak and neutron capture (n-capture) process elements in four Ba stars HD 26886, HD 27271, HD 50082 and HD 98839 based on high resolution, high signal-to-noise spectra. We find that all of these Ba stars are disk stars. Their alpha and iron peak elements are similar to the solar abundances. The n-capture process elements are overabundant relative to the Sun. In particular, the second peak slow neutron capture process (s-process) elements, Ba and La, are higher than the first peak s-process elements, Y and Zr. Analyzing the abundances of four sample stars, the heavy-element abundances of the strong Ba star HD 50082 are higher than those of other three mild Ba stars. The stellar mass of the strong Ba star HD 50082 is 1.32 Msun (+0.28, -0.22 Msun), which is consistent with the average mass of strong Ba stars (1.5 Msun). For mild Ba star HD 27271, we derive 1.90 Msun (+0.25, -0.20 Msun), consistent with the average mass of mild Ba stars (1.9 Msun, with 0.6 Msun white dwarf companion). For mild Ba star HD 26886, the derived 2.78 Msun (+0.75, -0.78 Msun) is consistent with the average 2.3 Msun of mild Ba stars with 0.67 Msun companion white dwarfs within the errors. Mass of mild Ba star HD 98839 is high to 3.62 Msun, which inspires more thoughts on the formation of Ba star phenomenon. Using our angular momentum conservation theoretical model of wind accretion of Ba binary systems, we obtain the theoretical heavy-element abundances of Ba stars that best fit our data. The results show that the observed abundances of the typical strong Ba star HD 50082 and the typical mild Ba star HD 27271 are consistent with the theoretical results very well. This suggests that their heavy-element abundances were caused by accreting the ejecta of AGB stars, the progenitors of the present white dwarf companions, through stellar wind. However, wind accretion scenario cannot explain the observed abundance pattern of the mild Ba star HD 26886 with shorter orbital period (P= 1263.2 d). The mild Ba star HD 98839 with high mass (up to 3.62 Msun) and very long orbital period (P> 11 000 d) may be either a star with the heavy elements enriched by itself or a ``true Ba" star. Table 3 and Tables \\ref{tab5}(1) to \\ref{tab5}(4) are only available in electronic form at http://www.edpsciences.org

  8. Iron promotes protein insolubility and aging in C. elegans

    PubMed Central

    Klang, Ida M.; Schilling, Birgit; Sorensen, Dylan J.; Sahu, Alexandria K.; Kapahi, Pankaj; Andersen, Julie K.; Swoboda, Peter; Killilea, David W.; Gibson, Bradford W.; Lithgow, Gordon J.

    2014-01-01

    Many late-onset proteotoxic diseases are accompanied by a disruption in homeostasis of metals (metallostasis) including iron, copper and zinc. Although aging is the most prominent risk factor for these disorders, the impact of aging on metallostasis and its role in proteotoxic disease remain poorly understood. Moreover, it is not clear whether a loss of metallostasis influences normal aging. We have investigated the role of metallostasis in longevity of Caenorhabditis elegans. We found that calcium, copper, iron, and manganese levels increase as a function of age, while potassium and phosphorus levels tend to decrease. Increased dietary iron significantly accelerated the age-related accumulation of insoluble protein, a molecular pathology of aging. Proteomic analysis revealed widespread effects of dietary iron in multiple organelles and tissues. Pharmacological interventions to block accumulation of specific metals attenuated many models of proteotoxicity and extended normal lifespan. Collectively, these results suggest that a loss of metallostasis with aging contributes to age-related protein aggregation. PMID:25554795

  9. Copper Delivery by Metallochaperone Proteins

    SciTech Connect

    Rosenzweig, A.C. (NWU)

    2010-03-08

    Copper is an essential element in all living organisms, serving as a cofactor for many important proteins and enzymes. Metallochaperone proteins deliver copper ions to specific physiological partners by direct protein-protein interactions. The Atx1-like chaperones transfer copper to intracellular copper transporters, and the CCS chaperones shuttle copper to copper,zinc superoxide dismutase. Crystallographic studies of these two copper chaperone families have provided insights into metal binding and target recognition by metallochaperones and have led to detailed molecular models for the copper transfer mechanism.

  10. Pulsed copper halide vapor lasers

    NASA Astrophysics Data System (ADS)

    Kazarian, M. A.; Petrash, G. G.; Trofimov, A. N.

    The theory and the performance characteristics of copper halide lasers are examined with reference to recent theoretical and experimental research in the field of metal vapor lasers. The discussion covers gas discharge tubes, comparative characteristics of copper halide lasers, determination of the metastable level decomposition rates in copper chloride and copper bromide lasers, and spectroscopic measurements of the discharge plasma in copper halide lasers. Attention is also given to the kinetics of copper atoms formation in copper halide lasers and calculation of the kinetic characteristics of copper halide lasers.

  11. Iron and alloys of iron. [lunar resources

    NASA Technical Reports Server (NTRS)

    Sastri, Sankar

    1992-01-01

    All lunar soil contains iron in the metallic form, mostly as an iron-nickel alloy in concentrations of a few tenths of 1 percent. Some of this free iron can be easily separated by magnetic means. It is estimated that the magnetic separation of 100,000 tons of lunar soil would yield 150-200 tons of iron. Agglutinates contain metallic iron which could be extracted by melting and made into powder metallurgy products. The characteristics and potential uses of the pure-iron and iron-alloy lunar products are discussed. Processes for working iron that might be used in a nonterrestrial facility are also addressed.

  12. The nature of the F str lambda 4077 stars. 3: Spectroscopy of the barium dwarfs and other CP stars

    NASA Technical Reports Server (NTRS)

    North, P.; Berthet, S.; Lanz, T.

    1994-01-01

    The abundances of C, O, Al, Ca, iron-peak and s-process elements have been derived from high-resolution spectra for a sample of stars classified as F str lambda 4077 by Bidelman. Among the 20 stars mentioned by Bidelman, we have discovered 8 barium dwarfs (or CH subgiants, according to Bond's terminology), while a 9th star, HD 182274, was already known as a CH subgiant. In addition, we have analyzed three barium stars taken from the list of Lu et al. (1983) which are probably dwarfs rather than giants, and three CH subgiants. The other 11 F str lambda 4077 stars resemble either the delta Delphini stars, since their iron abundance is enhanced while Ca is normal, or are probably spectrum composites. A few Am, Ap, lambda Bootis and normal stars have been analyzed for comparison. In particular, we have included three lambda Boo candidates, selected from their photometric properties, and their iron deficiency is confirmed. The spectroscopic, photometric and statistical evidences concerning the Ba dwarfs, support the idea that these stars may be the main sequence counterparts, and possibly the progenitors of the Ba giants. The C/O ratio varies in these stars from normal values to a maximum of 1.5, but mostly within 0.6 and 1.2. Some of these objects may therefore be considered, in this sense, as carbon stars. On the other hand, the abundances of carbon and s-process elements relative to iron are inversely correlated with metallicity, and may even exceed significantly those of typical, solar-metallicity carbon stars. Metal-deficient C stars must therefore have (C/Fe) greater than or approximately equal to 1 and (s/Fe) greater than or approximately equal to 1.5 as soon as (Fe/H) less than or approximately equal to -1. The neutron exposure is shown to increase when the metallicity decreases, which is compatible with the C-13 (alpha, n) O-16 neutron source, but not with the Ne-22 (alpha, n) Mg-25 one. The evolutionary state (within the main sequence) of the Ba dwarfs, is rediscussed in relation with their photometric and spectroscopic surface gravity, but it remains unclear.

  13. Iron deficiency anemia in an athlete associated with Campylobacter pylori-negative chronic gastritis

    SciTech Connect

    Mack, D.; Sherman, P. (Univ. of Toronto (Canada))

    1989-08-01

    A 14-year-old athletic boy with a 1-year history of decreased exercise tolerance presented with unexplained iron deficiency anemia. Panendoscopy, colonoscopy, and barium contrast studies of the gastrointestinal tract were normal. However, persistent uptake of radionuclide using a {sup 99m}technetium-sucralfate scan suggested inflammation localized to the stomach. Mucosal biopsies demonstrated acute and chronic gastritis that was not associated with the presence of Campylobacter pylori.

  14. Refractories for Copper Production

    Microsoft Academic Search

    MARK E. SCHLESINGER

    1996-01-01

    The furnaces used for producing molten copper from concentrates and scrap - flash: smelters, converters, and anode and fire-refining furnaces - present a unique combination of challenges to refractory life. Highly aggressive slags, mechanical stresses, batch operation, and increasingly higher operating temperatures all combine to destroy most refractory materials. Over the past generation, copper producers have adopted refractory materials biased

  15. Ions Sputtered from Copper

    Microsoft Academic Search

    R. C. Bradley; E. Ruedl

    1962-01-01

    Positive ions sputtered from copper under a variety of different bombardment and surface conditions have been mass analyzed and found to include species characteristic of the incident ions (``reflected'' ions), of copper and some of its compounds, and of alkali metal impurities. A model is described which accounts for most of the properties of the ``reflected'' ions, not in terms

  16. Iron and iron derived radicals

    SciTech Connect

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  17. Separation of lanthanum, hafnium, barium and radiotracers yttrium-88 and barium-133 using crystalline zirconium phosphate and phosphonate compounds as prospective materials for a Ra-223 radioisotope generator.

    PubMed

    Möller, Teresia; Bestaoui, Naima; Wierzbicki, Melissa; Adams, Todd; Clearfield, Abraham

    2011-07-01

    Crystalline hybrid organic/inorganic ion exchangers based on zirconium phosphate and phosphonate compounds were evaluated for application in radium-223 generator for radiopharmaceutical applications. Various compositions were synthesized and the selectivity of these materials was determined for inactive lanthanum, hafnium and barium, and radiotracers yttrium-88 and barium-133. The hybrid materials show very efficient lanthanum/barium separation; the response for zirconium phosphate was even better. A small-scale column loaded with pelletized zirconium phosphate compound demonstrated excellent retention of (88)Y and release of (133)Ba. PMID:21421323

  18. Genetics Home Reference: Iron-refractory iron deficiency anemia

    MedlinePLUS

    ... Genetic disorder catalog Conditions > Iron-refractory iron deficiency anemia On this page: Description Genetic changes Inheritance Diagnosis ... July 2014 What is iron-refractory iron deficiency anemia? Iron-refractory iron deficiency anemia is one of ...

  19. Serum ceruloplasmin and ferroxidase activity are decreased in HFE C282Y homozygote male iron-overloaded patients

    Microsoft Academic Search

    Fabrice Lainé; Martine Ropert; Caroline Le Lan; Olivier Loréal; Eric Bellissant; Christine Jard; Michel Pouchard; André Le Treut; Pierre Brissot

    2002-01-01

    Background\\/Aims: A body of evidence suggests that ceruloplasmin (Cp), the major serum copper-containing protein, acts in iron metabolism due to its ferroxidase activity which appears essential for iron movements and exchanges.Methods: The present study investigated the serum levels of Cp and its ferroxidase activity in 53 C282Y homozygote genetic hemochromatosis (38 iron overloaded, 15 iron depleted) patients as compared to

  20. Bioaccessibility and Solubility of Copper in Copper-Treated Lumber

    EPA Science Inventory

    Micronized copper (MC)-treated lumber is a recent replacement for Chromated Copper Arsenate (CCA) and Ammonium Copper (AC)-treated lumbers; though little is known about the potential risk of copper (Cu) exposure from incidental ingestion of MC-treated wood. The bioaccessibility o...