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1

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

Microsoft Academic Search

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

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

2004-01-01

2

Copper Compatible Barium Titanate Thin Films for Embedded Passives  

Microsoft Academic Search

Barium titanate thin films have been prepared by chemical solution deposition on 18 µ m thick, industry standard copper foils in the absence of chemical barrier layers. The final embodiment exhibits randomly oriented BaTiO3 grains with diameters between 0.1 and 0.3 µ m, and an equiaxed morphology. The average film thickness is 0.6 µ m and the microstructure is free

Jon Ihlefeld; Brian Laughlin; Alisa Hunt-Lowery; William Borland; Angus Kingon; Jon-Paul Maria

2005-01-01

3

Molecular Mediators Governing Iron-Copper Interactions  

PubMed Central

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

Gulec, Sukru; Collins, James F.

2015-01-01

4

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

E-print Network

with iron oxide and barium titanate nanoparticles Z. Guo a,*, S.-E. Lee a , H. Kim a , S. Park a , H.T. Hahn the introduction of the dielectric barium titanate nanoparticle into Fe2O3/PU nanocomposites. The permeability (PU) nanocomposites reinforced with magnetic iron oxide nanoparticles and/or dielectric barium

Guo, John Zhanhu

5

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

Microsoft Academic Search

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

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

2007-01-01

6

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

Microsoft Academic Search

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

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

2007-01-01

7

Electrolytic Corrosion of Iron and Copper  

Microsoft Academic Search

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

W. F. Higgins

1954-01-01

8

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

E-print Network

500 m plate of ceramic barium strontium titanate having similar in-plane sizes. A frequency spectrum iron garnet YIG film and barium strontium titan- ate BST slab has been investigated. Less attentionQ factor of dual-tunable microwave resonators based on yttrium iron garnet and barium strontium

Srinivasan, Gopalan

9

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

E-print Network

recently have shown that a barium ferrite parasitic phase was responsible for RT magnetic hysteresis [91 In-situ formation of barium ferrite in iron doped "tetragonal tungsten bronze": Elaboration their room temperature multiferroics properties to the occurrence of barium ferrite parasitic phases

Paris-Sud XI, Université de

10

Moessbauer Study on Barium Ferrite Magnetic Recording Media and Iron-Based Thin Films  

Microsoft Academic Search

Mossbauer spectroscopy and magnetic measurements (VSM) are employed to study pure and Co-Ti substituted barium ferrite and iron-based thin films. For substituted barium ferrite, the Mossbauer spectra are superposition of five subspectra because of the five different environments of the Fe^{3+} ions. We observe that spectral peak width broadens as Co-Ti substitution increases, eventually leading to very poor resolution. To

Jenny Ou. Hai

1993-01-01

11

HAFNIUM AS ALLOYING ELEMENT IN COPPER, IRON, AND NICKEL  

Microsoft Academic Search

The electrical resistance, the thermal EMF, the coefficient of thermal ; expansion, and the hardness of copper, iron, and nickel with different additions ; of hafnium were measured and the solubility of hsfnium in copper, iron and nickel ; was determined. The influence of the addition of hafnium on the ; recrystallization of copper, iron and nickel was investigated, too.

Reinbach

1960-01-01

12

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

E-print Network

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. ...

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

2004-01-01

13

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

SciTech Connect

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.

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

1988-01-01

14

Cooled and uncooled infrared detectors based on yttrium barium copper oxide  

Microsoft Academic Search

We review performance and physical characteristics of yttrium barium copper oxide (YBCO) compound as an infrared (IR) photodetector. YBCO has been used as the IR detector material in both superconducting (oxygen-rich) and semiconducting (oxygen-depleted) phases. YBCO in its crystalline, Yba2Cu3O6+x phase with x>0.95 is a high-temperature superconducting material with the superconducting transition Tcapproximately equals 90K. The superconducting YBCOIR detectors operate

Roman Sobolewski; Donald P. Butler; Zeynep Celik-Butler

2001-01-01

15

The effect of copper excess on iron metabolism in sheep.  

PubMed

Sheep were treated with large amounts of copper (20 mg of CuSO4,5H2O/kg body wt. per day) for 9 weeks to examine the effect of copper excess on iron metabolism. In addition to confirming that massive haemolysis and accumulation of copper occurs in the liver, kidney and plasma after 7 weeks of exposure to excess copper, it was observed that excess copper produced an increased plasma iron concentration and transferrin saturation within 1 week. Further, iron preferentially accumulated in the spleen between 4 and 6 weeks of copper treatment, producing 3-fold increases in the iron content of both the ferritin and non-ferritin fractions. A 3-4 fold increase was also observed in the amount of ferritin that could be isolated from the spleen. The copper treatment had little or no effect on the concentration of iron in the liver and bone marrow. The following properties of erythrocytes were also unaffected by copper treatment: size, haemoglobin content and pyruvate kinase activity, although the erythrocyte concentration of copper increased after 6 weeks. Copper accumulated in the spleen between 6 and 9 weeks, probably owing to the phagocytosis of erythrocytes containing high concentrations of copper. The data suggest that copper excess influences iron metabolism, initially by causing a compensated haemolytic anaemia, and later by interfering with re-utilization of iron from ferritin in the reticuloendothelial cells of the spleen. PMID:629772

Theil, E C; Calvert, K T

1978-01-15

16

The effect of copper excess on iron metabolism in sheep.  

PubMed Central

Sheep were treated with large amounts of copper (20 mg of CuSO4,5H2O/kg body wt. per day) for 9 weeks to examine the effect of copper excess on iron metabolism. In addition to confirming that massive haemolysis and accumulation of copper occurs in the liver, kidney and plasma after 7 weeks of exposure to excess copper, it was observed that excess copper produced an increased plasma iron concentration and transferrin saturation within 1 week. Further, iron preferentially accumulated in the spleen between 4 and 6 weeks of copper treatment, producing 3-fold increases in the iron content of both the ferritin and non-ferritin fractions. A 3-4 fold increase was also observed in the amount of ferritin that could be isolated from the spleen. The copper treatment had little or no effect on the concentration of iron in the liver and bone marrow. The following properties of erythrocytes were also unaffected by copper treatment: size, haemoglobin content and pyruvate kinase activity, although the erythrocyte concentration of copper increased after 6 weeks. Copper accumulated in the spleen between 6 and 9 weeks, probably owing to the phagocytosis of erythrocytes containing high concentrations of copper. The data suggest that copper excess influences iron metabolism, initially by causing a compensated haemolytic anaemia, and later by interfering with re-utilization of iron from ferritin in the reticuloendothelial cells of the spleen. PMID:629772

Theil, E C; Calvert, K T

1978-01-01

17

Synthesis and properties of barium titanate solid solution thin films deposited on copper substrates  

NASA Astrophysics Data System (ADS)

Barium titanate thin films were deposited via chemical solution deposition using a hybrid-chelate chemistry directly on copper foil substrates. A process was developed to crystallize and densify the ferroelectric films at 900°C by using a reductive atmosphere containing nitrogen, hydrogen, water vapor, and oxygen impurities such that film constituents were oxidized to form barium titanate and the foil substrate remained metallic. The crystallized films are polycrystalline with equiaxed morphology and average grain diameters in excess of 100 mn. The dielectric properties exhibit permittivities in excess of 1800 at room temperature and zero bias with tunabilites of greater than 90% and high field loss tangents of less than 1%. The phase transition temperature and temperature coefficient of capacitance modified by partially substituting zirconium, hafnium, and tin for titanium. The resulting films were single phase and the phase transition shifts were consistent with bulk materials. A reduction in permittivity was observed for increasing substituent level and was attributed to a reduction in grain size for both barium titanate zirconate and barium titanate hafnate. Processing conditions were chosen to stabilize Sn2+ during the firing process in an attempt to flux the system and increase grain size. The barium titanate stannate films had less reduction in grain size per substituent level than either zirconium or hafnium, however a similar reduction in permittivity was observed. The diminished dielectric response was explained by a defect reaction involving divalent tin and oxygen vacancies that quenched the extrinsic domain response to the dielectric constant. Barium borate fluxes were used to improve densification and crystallinity. Barium borate additions between 0 and 3% uniformly increased grain size and density, while levels greater than 3% resulted in anomalous grain growth. Films with exaggerated grains show tetragonal peak splitting in the X-ray diffraction patterns, consistent with bulk barium titanate. In materials without exaggerated grain growth, dielectric measurements revealed permittivities in excess of 3000 at room temperature (for average grain sizes of approximately 160 nm). This value is equivalent to the finest-prepared bulk ceramics and substantially greater than any polycrystalline film ever reported. This has been attributed to in improvement in film crystallinity. These two accomplishments - tetragonal crystal symmetry and permittivities in excess of 3000 - represent dramatic breakthroughs in ferroelectric thin film technology. (Abstract shortened by UMI.)

Ihlefeld, Jon Fredrick

18

Copper and nickel partitioning in iron meteorites  

NASA Technical Reports Server (NTRS)

Trace element analyses using proton induced X-ray emission and synchrotron X-ray fluorescence have been made on metal and troilite from nine iron meteorites representing five geochemical groups. Nickel and copper distribution coefficients D (troilite/metal) vary by factors of 600 and 20, respectively, correlate positively with kamacite bandwidth and correlate negatively with bulk nickel content. Meteorites with bulk Ni of less than 10 percent have Cu-enriched troilite while those with Ni greater than 10 percent have Cu-depleted troilite. Since magmatic evolution and partial melting will produce Cu-enriched troilite only, the observation of Cu-depleted troilite in Ni-rich meteorites is evidence for subsolidus reequilibration, a process which reduces D(Cu) by transfer of Cu to exsolving metal. Elemental redistribution may have played an important role in establishing the present chemical trends in iron meteorites.

Sutton, S. R.; Delaney, J. S.; Prinz, M.; Smith, J. V.

1987-01-01

19

Iron versus Copper II. Principles and Applications in Bioinorganic Chemistry.  

ERIC Educational Resources Information Center

Discusses the differences between iron and copper. Describes various aspects of the behaviors of these two elements, including those of biological and environmental significance. Addresses the evolution of the atmosphere and sedimentary ore formation, the phylogeny of iron and copper, and some anthropological notes regarding the use of the metals.…

Ochiai, Ei-Ichiro

1986-01-01

20

Effects of Small Additions of Copper and Copper + Nickel on the Oxidation Behavior of Iron  

Microsoft Academic Search

This study was undertaken to investigate the effect of small amounts of copper and copper + nickel additions on the oxidation\\u000a rate and oxide\\/metal interface microstructure of iron. Three iron-based alloys were compared: 0.3 wt pct copper, 0.3 wt pct\\u000a copper-0.1 wt pct nickel, and 0.3 wt pct copper-0.05 wt pct nickel. Alloy samples were oxidized in air at 1150 °C for 60,\\u000a 300, and 600 seconds. Pure iron

Bryan Webler; Lan Yin; Seetharaman Sridhar

2008-01-01

21

Short-term effects of intratracheal installations of yttrium barium copper oxide  

SciTech Connect

Inhalation exposures to the new high-temperature ({Tc}) superconductor (SC) materials can occur during manufacturing and fabrication processes. In this exploratory study, we examined the pulmonary response to the deposition of an yttrium barium copper oxide SC powder. Groups of Sprague-Dawley rats were intratracheally instilled with either 10 mg or 20 mg of SC in phosphate-buffered saline (PBS) or with PBS only. The animals were sacrificed 60 days later for histopathologic assessments of their lungs. Lung lesions in the 10-mg SC group were found mainly in alveolar ducts and proximal alveoli. The lesions consisted of variably sized foci of interstitial thickening involving accumulations of macrophages. These interstitial aggregates were often times centered around one or more extracellular crystals, which, presumably, were retained SC product. Trichome stains also demonstrated the presence of fibrosis in the walls of alveoli surrounding the granulomas. Similar interstitial-macrophage accumulations and fibrosis were observed in rats instilled with 20 mg of SC. However, alveolus like structures lined by ciliated cuboidal epithelium near interstitial granulomas were additionally found in the lungs of some of the animals in this latter group. These results suggest SC material of the yttrium barium copper oxide type may represent a potential exposure hazard to the lung.

London, J.E.; Newkirk, L.R.; Lehnert, B.E.

1990-12-01

22

Copper's influence on iron metabolism in K562 cells  

SciTech Connect

Copper deficiency is associated with a cellular defect in iron metabolism that results in poor hemoglobin synthesis. In order to determine this mechanisms, K562 cells, a human erythroleukemic cell line, were incubated with 1 mM bethocuproine disulfonic acid (BCS) to produce a copper deficiency or were supplemented with 8 {mu}M copper. Hemoglobin was simultaneously induced in some cells by the addition of 25 {mu}M hemin to the culture medium. Incubation with BCS resulted in a 30 to 40% reduction in intracellular Cu/Zn superoxide dismutase activity while supplementation resulted in a 20 to 50% increase in activity. The authors then examined the effect of these copper manipulations on {sup 59}Fe uptake from transferrin, on ferritin levels and on hemoglobin levels. Hemoglobin was only slightly affected by the copper treatments. In both noninduced cells and induced cells, copper supplementation resulted in a greater level of intracellular iron, a greater level of immunoreactive ferritin, and an enhanced uptake of {sup 59}Fe from transferrin. In BCS-incubated cells, intracellular iron, ferritin and {sup 59}Fe uptake from transferrin were reduced by at least 50%. Because the ferritin levels were reduced, intracellular iron mobilization did not appear to be impaired in copper deficiency. The results suggest that copper deficiency impairs the transport of iron by transferrin into the cell.

Percival, S.S.; Armstrong, E. (Univ. of Florida, Gainesville, (United States))

1991-03-15

23

Serum iron, total iron binding capacity, plasma copper and hemoglobin types in anemic and poikilocytic calves.  

PubMed Central

Ninety-eight calves were studied to determine if anemia and poikilocytosis were related to iron or copper status or hemoglobin type. No significant differences were found in serum iron, total iron binding capacity, marrow iron, plasma copper or hemoglobin type between affected and normal calves. Poikilocytes were strongly inversely correlated (-0.9177) with age. Calves less than six weeks of age had more poikilocytes, lower serum iron, higher total iron binding capacity, less adult hemoglobin and more neonatal and fetal hemoglobin than calves greater than six weeks of age. Images Fig. 1. PMID:2412677

McGillivray, S R; Searcy, G P; Hirsch, V M

1985-01-01

24

Ascorbate autoxidation in the presence of iron and copper chelates.  

PubMed

Chelates can inhibit the iron- and copper-catalyzed autoxidation of ascorbate at pH 7.0. Diethylenetriaminepentaacetic acid (DTPA or DETAPAC) and Desferal (deferoximane mesylate) slow the iron-catalyzed oxidation of ascorbate as effectively as reducing the trace levels of contaminating iron in buffers with Chelex resin. DETAPAC, EDTA and HEDTA (N-(2-hydroxyethyl)-ethylenediaminetriacetic acid) are effective at slowing the copper-catalyzed autoxidation of ascorbate while Desferal is ineffective. The ability to inhibit ascorbate autoxidation appears to parallel the rate of the reaction of superoxide with the iron chelate. PMID:2851502

Buettner, G R

1986-01-01

25

Old iron, young copper: from Mars to Venus.  

PubMed

Iron and copper are metals which play an important role in the living world. From a brief consideration of their chemistry and biochemistry we conclude that the early chemistry of life used water soluble ferrous iron while copper was in the water-insoluble Cu(I) state as highly insoluble sulphides. The advent of oxygen was a catastrophic event for most living organisms, and can be considered to be the first general irreversible pollution of the earth. In contrast to the oxidation of iron and its loss of bioavailability as insoluble Fe(III), the oxidation of insoluble Cu(I) led to soluble Cu(II). A new iron biochemistry became possible after the advent of oxygen, with the development of chelators of Fe(III), which rendered iron once again accessible, and with the control of the potential toxicity of iron by its storage in a water soluble, non-toxic, bio-available storage protein (ferritin). Biology also discovered that whereas enzymes involved in anaerobic metabolism were designed to operate in the lower portion of the redox spectrum, the arrival of dioxygen created the need for a new redox active metal which could attain higher redox potentials. Copper, now bioavailable, was ideally suited to exploit the oxidizing power of dioxygen. The arrival of copper also coincided with the development of multicellular organisms which had extracellular cross-linked matrices capable of resisting attack by oxygen free radicals. After the initial 'iron age' subsequent evolution moved, not towards a 'copper age', but rather to an 'iron-copper' age. In the second part of the review, this symbiosis of iron and copper is examined in yeast. We then briefly consider iron and copper metabolism in mammals, before looking at iron-copper interactions in mammals, particularly man, and conclude with the reflection that, as in Greek and Roman mythology, a better understanding of the potentially positive interactions between Mars (iron) and Venus (copper) can only be to the advantage of our species. PMID:11508852

Crichton, R R; Pierre, J L

2001-06-01

26

Effect of copper and graphite addition on sinterability of iron  

Microsoft Academic Search

In ferrous powder metallurgy, copper and graphite are used as common alloying elements. Copper melts at low temperature compared\\u000a to iron and forms liquid which promote interparticle bond formation. However, it also results in compact swelling. To negate\\u000a this, graphite is used as an additive. This study examines the influence of copper and graphite addition on the densification,\\u000a dimensional changes,

Felege Nekatibeb; A. Raja Annamalai; Anish Upadhyaya

2011-01-01

27

Iron, Zinc and Copper in Selected Tissues of Rabbits under Increasing Exposure to Iron  

Microsoft Academic Search

I. Maciejewska-Paszek, E. Grochowska-Niedworok, M. Wardas, M. Skiba:Iron, Zinc and Copper in Selected Tissues of Rabbits under Increasing Exposure to Iron. Acta Vet. Brno 2005, 74: 551-555. The aim of this study was to demonstrate the disturbance of zinc\\/copper balance in tissues as the possible accelerating factor of liver damage after short- and long-term exposure to high doses of iron

I. MACIEJEWSKA-PASZEK; E. GROCHOWSKA-NIEDWOROK; M. WARDAS; M. SKIBA

28

Moessbauer study on barium ferrite magnetic recording media and iron-based thin films  

SciTech Connect

Moessbauer spectroscopy and magnetic measurements (VSM) are employed to study pure and Co-Ti substituted barium ferrite and iron-based thin films. For substituted barium ferrite, the Moessbauer spectra are superposition of five subspectra because of the five different environments of the Fe[sup 3+] ions. The author observes that spectral peak width broadens as Co-Ti substitution increases, eventually leading to very poor resolution. In this work, a series of Co-Ti substituted barium ferrite samples have been studied at room temperature in an applied field only up to 0.8 T with transmission geometry Moessbauer spectroscopy. A difference in applied-field spectra compared with zero-field spectra is observed. A computer program for generating applied Moessbauer spectra for powdered ferrimagnetic samples [11] has been implemented. Assuming a 2-sublattice structure, and comparing the simulated and experimental spectra, the author obtains a value of the anisotropy field for pure barium ferrite at room temperature of 0.35 [+-] 0.05 T. Conversion electron Moessbauer spectrometry has been used to study two series of Fe films sputtered at high and low argon pressures with variable thickness of 50 to 1000 nm. The relative intensities of the (2,5) components of the Zeeman sextet decrease with increasing film thickness for samples deposited at high argon pressure. In contrast, films deposited for samples deposited at high argon pressure. In contrast, films deposited at low argon pressure exhibit only a small decrease in (2,5) intensities over the thickness range studied, suggesting that moments retain in-plane orientation. The analysis shows that CEMS is a sensitive tool to investigate magnetic moment orientation in thin films and can supply useful information on the perpendicular anisotropy K[perpendicular] of thin films which can not be obtained by VSM or torque measurements.

Hai, J.O.

1993-01-01

29

Kinetics of iron–copper sulphides oxidation in relation to protohistoric copper smelting  

Microsoft Academic Search

This article deals with one specific step of the copper extractive metallurgy process: the roasting of iron–copper sulphides.\\u000a It aims at shedding light on an archaeological issue: the reconstruction of the copper extractive metallurgy processes during\\u000a protohistory (IVe–IIe millennium BC). Experimental simulations are performed at laboratory scale by modelizing the conditions of protohistoric\\u000a furnaces. Kinetic of roasting is studied by

Emilien BurgerDavid Bourgarit; David Bourgarit; Vincent Frotté; Fabien Pilon

2011-01-01

30

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

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

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

2014-07-01

31

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

NASA Technical Reports Server (NTRS)

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.

Buckley, D. H.

1978-01-01

32

Static and dynamic photoinduced magnetic effects in yttrium-iron garnet lightly doped with barium ions  

SciTech Connect

In yttrium-iron garnet lightly doped with barium, direct measurements of the photoinduced changes in magnetostrictive strains disagree with those in magnetostriction constants at 78-100 K. This is attributed to a considerable photoinduced modification of the initial state in this sample due to a redistribution of the charge (during illumination) between cations of the ferromagnetic octahedral sublattice. In the same sample, the temperature dependence of the photoinduced disaccomodation of magnetic permeability characterizing the initial demagnetized state is measured and calculated. A change in the electron mechanism of the phenomenon during the transition to room temperature is shown. The conclusion about the promising prospects for using such samples for remagnetization by light is advanced.

Vorob'eva, N. V., E-mail: vnv@anrb.ru; Khalilov, R. Z. [Russian Academy of Sciences, Institute of Molecule and Crystal Physics (Russian Federation)

2012-04-15

33

Dysregulation of iron and copper homeostasis in nonalcoholic fatty liver.  

PubMed

Elevated iron stores as indicated by hyperferritinemia with normal or mildly elevated transferrin saturation and mostly mild hepatic iron deposition are a characteristic finding in subjects with non-alcoholic fatty liver disease (NAFLD). Excess iron is observed in approximately one third of NAFLD patients and is commonly referred to as the "dysmetabolic iron overload syndrome". Clinical evidence suggests that elevated body iron stores aggravate the clinical course of NAFLD with regard to liver-related and extrahepatic disease complications which relates to the fact that excess iron catalyses the formation of toxic hydroxyl-radicals subsequently resulting in cellular damage. Iron removal improves insulin sensitivity, delays the onset of type 2 diabetes mellitus, improves pathologic liver function tests and likewise ameliorates NAFLD histology. Several mechanisms contribute to pathologic iron accumulation in NAFLD. These include impaired iron export from hepatocytes and mesenchymal Kupffer cells as a consequence of imbalances in the concentrations of iron regulatory factors, such as hepcidin, cytokines, copper or other dietary factors. This review summarizes the knowledge about iron homeostasis in NAFLD and the rationale for its therapeutic implications. PMID:25729473

Aigner, Elmar; Weiss, Günter; Datz, Christian

2015-02-27

34

Dysregulation of iron and copper homeostasis in nonalcoholic fatty liver  

PubMed Central

Elevated iron stores as indicated by hyperferritinemia with normal or mildly elevated transferrin saturation and mostly mild hepatic iron deposition are a characteristic finding in subjects with non-alcoholic fatty liver disease (NAFLD). Excess iron is observed in approximately one third of NAFLD patients and is commonly referred to as the “dysmetabolic iron overload syndrome”. Clinical evidence suggests that elevated body iron stores aggravate the clinical course of NAFLD with regard to liver-related and extrahepatic disease complications which relates to the fact that excess iron catalyses the formation of toxic hydroxyl-radicals subsequently resulting in cellular damage. Iron removal improves insulin sensitivity, delays the onset of type 2 diabetes mellitus, improves pathologic liver function tests and likewise ameliorates NAFLD histology. Several mechanisms contribute to pathologic iron accumulation in NAFLD. These include impaired iron export from hepatocytes and mesenchymal Kupffer cells as a consequence of imbalances in the concentrations of iron regulatory factors, such as hepcidin, cytokines, copper or other dietary factors. This review summarizes the knowledge about iron homeostasis in NAFLD and the rationale for its therapeutic implications. PMID:25729473

Aigner, Elmar; Weiss, Günter; Datz, Christian

2015-01-01

35

Iron may play a role in pancreatic atrophy in copper deficiency  

SciTech Connect

The present study was undertaken to determine if pancreatic atrophy in copper deficient rats fed fructose is associated with excessive iron deposition. Weanling male and female rats were fed a copper deficient or copper adequate diet containing 62% carbohydrate as either fructose or starch. Another group of weanling rats consumed a copper deficient diet containing fructose that was low in iron. After consuming their respective diets for five weeks, the highest pancreatic iron concentration was seen in male rats consuming the copper deficient diet containing fructose. These animals also exhibited pancreatic atrophy. In contrast, neither copper deficient female rats fed fructose nor males fed starch exhibited pancreatic atrophy and their pancreata did not contain high levels of iron. In addition, reducing the availability of dietary iron in copper deficient rats fed fructose decreased pancreatic iron concentration and ameliorated the pathology. The data suggest that pancreatic atrophy in copper deficiency may be related to iron deposition in that tissue.

Fields, M.; Lewis, C.G.; Lure, M.D. (Georgetown Univ. Medical Center, Washington, DC (United States) Dept. of Agriculture, Beltsville, MD (United States) Univ. of Maryland, College Park (United States))

1991-03-15

36

Strontium, silver, tin, iron, tellurium, gallium, germanium, barium and vanadium levels in foodstuffs from the Second French Total Diet Study  

Microsoft Academic Search

A total of 28 minerals and trace elements from 1319 food samples typically consumed by the French population were determined during the second French Total Diet Study (TDS). Among the main trace elements analysed by inductively coupled plasma-mass spectrometry (ICP-MS) after microwave-assisted digestion, strontium (Sr), silver (Ag), tin (Sn), barium (Ba), iron (Fe), tellurium (Te), gallium (Ga), germanium (Ge) and

Sandrine Millour; Laurent Noël; Rachida Chekri; Christelle Vastel; Ali Kadar; Véronique Sirot; Jean-Charles Leblanc; Thierry Guérin

37

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)

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). .

Dunmore, Franklin John

1995-01-01

38

Ultrasound-enhanced copper removal by hydrous iron oxide adsorption  

SciTech Connect

A model system to investigate ultrasound-enhanced removal of metallic ions from aqueous solution by hydrous ferric oxide (HFO) adsorption has been conducted. The experimental data indicate that ultrasonic treatment of pre-formed HFO flocs can lead to enhanced removal of metallic ions from aqueous solution and that the level of enhancement is strongly correlated with the solution pH. Ultrasonic treatment has been shown to be effective at lowering the final solution concentration of copper species in the pH range 7.5--9.5 at copper to iron molar concentration ratios of 10 and 30%.

Campos, H.R. [Univ. de Tarapaca, Arica (Chile); Wheat, P.E. [Univ. of Northern Iowa, Cedar Falls, IA (United States). Dept. of Industrial Technology

1996-12-31

39

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

PubMed

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

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

2015-03-01

40

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

Microsoft Academic Search

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

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

1998-01-01

41

Methods for making a supported iron-copper catalyst  

DOEpatents

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.

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

1986-01-01

42

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

E-print Network

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

Chorover, Jon

43

Nuclear magnetic resonance of iron and copper disease states  

SciTech Connect

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.

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

44

Promotion of atherogenesis by copper or iron-Which is more likely?  

SciTech Connect

Iron levels increase in atherosclerotic lesions in cholesterol fed-rabbits and play a role in atherosclerosis. We investigated whether copper also rises. Male New Zealand White rabbits were fed high-cholesterol diets for 8 weeks. After sacrifice, lesion sizes were determined, and elemental analyses of the lesion and unaffected artery wall performed using nuclear microscopy. Unlike iron, lesion copper is decreased by about half compared with the unaffected artery wall, and much less copper than iron is present. Our data suggest that iron may be more likely to play a role in the promotion of atherosclerosis than copper.

Rajendran, Reshmi [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, MD7, 8 Medical Drive, Singapore 117597 (Singapore); Department of Biochemistry, National University of Singapore, MD7, 8 Medical Drive, Singapore 117597 (Singapore); Ren, Minqin [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, MD7, 8 Medical Drive, Singapore 117597 (Singapore); Ning, Pan [Department of Biochemistry, National University of Singapore, MD7, 8 Medical Drive, Singapore 117597 (Singapore); Tan Kwong Huat, Benny [Department of Pharmacology, National University of Singapore, MD7, 8 Medical Drive, Singapore 117597 (Singapore); Halliwell, Barry [Department of Biochemistry, National University of Singapore, MD7, 8 Medical Drive, Singapore 117597 (Singapore)]. E-mail: bchbh@nus.edu.sg; Watt, Frank [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, MD7, 8 Medical Drive, Singapore 117597 (Singapore)

2007-02-02

45

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

46

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)

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.

Ham, Kyungmin

47

VAPOR PHASE MERCURY SORPTION BY ORGANIC-SULFIDE COATED BIMETALLIC IRON-COPPER NANOPARTICLE AGGREGATES  

EPA Science Inventory

Tetra sulfide silane coated iron-copper nano-particle aggregates are found to be potentially very high capacity sorbents for vapor phase mercury capture. High equilibrium capacities were obtained for the silane coated iron copper nano-aggregate sorbent at 70 oC and 120 oC. Even a...

48

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2012-06-20

49

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

E-print Network

, . 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...

Miah, Md. Abdul Hamid

1961-01-01

50

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

NASA Astrophysics Data System (ADS)

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

Primc, D.; Makovec, D.

2015-01-01

51

Decomposition of the sulfates of copper, iron (II), iron (III), nickel, and zinc: XPS, SEM, DRIFTS, XRD, and TGA study  

Microsoft Academic Search

The bulk and surface characteristics during decomposition of the transition metal sulfates of copper, iron (II), iron (III), nickel, and zinc are investigated utilizing various spectroscopic techniques. An oxidized form of sulfur was detected on the surface during decomposition of all metal sulfate samples, except zinc sulfate. Surface characteristics were not necessarily representative of the bulk characteristics. Oxy-sulfate was observed

Ranjani V Siriwardane; James A Poston Jr; Edward P Fisher; Ming-Shing Shen; Angela L Miltz

1999-01-01

52

Hyperfine Field and Hyperfine Anomalies of Copper Impurities in Iron  

E-print Network

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)%.

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

53

Sequential injection lab-on-valve simultaneous spectrophotometric determination of trace amounts of copper and iron  

Microsoft Academic Search

A sequential injection (SI) method in a lab-on-valve (LOV) format for simultaneous spectrophotometric determination of copper and iron has been devised. The detection chemistry is based on the complex formation of 2-(5-bromo-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino]aniline (5-Br-PSAA) with copper(II) and\\/or iron(II) at pH 4.6. Copper(II) reacts with 5-Br-PSAA to form the complex which has an absorption maximum at 580nm but iron(III) does not react.

Shinsuke Ohno; Norio Teshima; Tadao Sakai; Kate Grudpan; Miroslav Polasek

2006-01-01

54

The commercialization of the FENIX iron control system for purifying copper electrowinning electrolytes  

NASA Astrophysics Data System (ADS)

The FENIX Hydromet Iron Control System was installed at Western Metals Copper Ltd.’s Mt. Gordon Operations in Queensland, Australia. The system uses a novel and patented ion-exchange resin to selectively remove iron from copper electrolyte at the solvent extraction/electrowinning plant. At Mt. Gordon, the system delivered significant savings in reagent consumption (acid and cobalt sulfate for electrowinning and lime for neutralization of the raffinate bleed) and has the potential to deliver higher current efficiencies in copper electrowinning, leading to increased copper production.

Shaw, D. R.; Dreisinger, D. B.; Lancaster, T.; Richmond, G. D.; Tomlinson, M.

2004-07-01

55

Copper Deficiency Leads to Anemia, Duodenal Hypoxia, Upregulation of HIF-2? and Altered Expression of Iron Absorption Genes in Mice  

PubMed Central

Iron and copper are essential trace metals, actively absorbed from the proximal gut in a regulated fashion. Depletion of either metal can lead to anemia. In the gut, copper deficiency can affect iron absorption through modulating the activity of hephaestin - a multi-copper oxidase required for optimal iron export from enterocytes. How systemic copper status regulates iron absorption is unknown. Mice were subjected to a nutritional copper deficiency-induced anemia regime from birth and injected with copper sulphate intraperitoneally to correct the anemia. Copper deficiency resulted in anemia, increased duodenal hypoxia and Hypoxia inducible factor 2? (HIF-2?) levels, a regulator of iron absorption. HIF-2? upregulation in copper deficiency appeared to be independent of duodenal iron or copper levels and correlated with the expression of iron transporters (Ferroportin - Fpn, Divalent Metal transporter – Dmt1) and ferric reductase – Dcytb. Alleviation of copper-dependent anemia with intraperitoneal copper injection resulted in down regulation of HIF-2?-regulated iron absorption genes in the gut. Our work identifies HIF-2? as an important regulator of iron transport machinery in copper deficiency. PMID:23555700

Matak, Pavle; Zumerle, Sara; Mastrogiannaki, Maria; El Balkhi, Souleiman; Delga, Stephanie; Mathieu, Jacques R. R.; Canonne-Hergaux, François; Poupon, Joel; Sharp, Paul A.; Vaulont, Sophie; Peyssonnaux, Carole

2013-01-01

56

VAPOR PHASE MERCURY SORPTION BY ORGANIC SULFIDE MODIFIED BIMETALLIC IRON-COPPER NANOPARTICLE AGGREGATES  

EPA Science Inventory

Novel organic sulfide modified bimetallic iron-copper nanoparticle aggregate sorbent materials have been synthesized for removing elemental mercury from vapor streams at elevated temperatures (120-140 °C). Silane based (disulfide silane and tetrasulfide silane) and alkyl sulfide ...

57

Removal of heavy metals and dyes by supported nano zero-valent iron on barium ferrite microfibers.  

PubMed

The binary nano zero-valent iron/barium ferrite (NZVI/BFO) microfibers with uniform diameters and high porosity were prepared by the organic gel-thermal selective reduction process. The composite microfibers are fabricated from nano zero-valent iron and nano BaFe12O19 grains. The effects of pH, adsorbent dosage, and contact time on the adsorption of heavy metals and dyes have been investigated. The adsorption isotherms of heavy metals and dyes on the microfibers are well described by the Langmuir model, in which the estimated adsorption capacities are 14.5, 29.9, 68.3 and 110.4 mg/g for Pb(II), As(V), Congo red and methylene blue, respectively. After five cycles, these microfibers still exhibit a high removal efficiency for As(V), Pb(II), Congo red and methylene blue. The enhanced adsorption characteristics can be attributed to the porous structure, strong surface activity and electronic hopping. Therefore, the magnetic NZVI/BFO microfibers can be used as an efficient, fast and high capacity adsorbent for heavy metals and dyes removal. PMID:24758012

Yang, Xinchun; Shen, Xiangqian; Jing, Maoxiang; Liu, Ruijiang; Lu, Yi; Xiang, Jun

2014-07-01

58

Superconducting Properties of Epitaxial Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA) Thin Films and Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA)/PRASEODYMIUM BARIUM(2) COPPER(3) OXYGEN(7-Z)/YTTRIUM BARIUM(2) COPPER(3) OXYGEN(7 - Heterostructures Grown by Pulsed Laser Deposition  

NASA Astrophysics Data System (ADS)

The study of the intrinsic behavior of high transition temperature copper-oxide superconductors (HTSC) has proven to be challenging because of the extreme sensitivity of their transport properties on material quality. These compounds are characterized by a high degree of structural and electrical anisotropy, and a very short superconductive coherence length of the same order as the size of the crystalline unit cell (~5-30 A). As a result, microscopic defects such as oxygen vacancies, cationic disorder, and the presence of minute impurities have a significant effect on electrical transport in these materials. Therefore, much effort has been expended in synthesizing sizable samples that are homogeneous, well characterized, and emenable to the study of the anisotropic properties of the HTSC. We have demonstrated that thin films of HTSC compounds such as rm YBa_2Cu_3O_{7 -delta}, which is a 92 K superconductor, can be synthesized easily by a technique known as pulsed laser deposition, and display superconducting properties comparable to or better than those of bulk poly- or single -crystalline samples. Furthermore, we have shown that layer by layer film growth permits unprecedented control on the characteristics of the sample allowing precise artificial adjustment of sample, properties on the scale of one or two unit cells; for example, we have epitaxially grown rm YBa_2Cu_3O_{7-delta}/PrBa _2Cu_3O_{7-z}/YBa_ 2Cu_3O_{7-delta} heterostructures (where rm PrBa_2Cu _3O_{7-z} is a non-superconducting isomorph of rm YBa_2Cu_3O_ {7-delta}) with individual layer thicknesses of a few tens of angstroms. We have applied such artificially structured systems to the fabrication of Josephson weak-links, and have successfully and reproducibly observed both the dc and ac Josephson effects in these junctions. We have also demonstrated thin films grown with the perovskite copper-oxide planes oriented perpendicular to the film surface. In such films, the current carrying copper-oxide planes of the superconductor are not continuous but are arranged in a mosaic, allowing for the simultaneous flow of superconducting currents along the in-plane and out-of-plane directions of the film. On a scale > 1 mum, this results in a quasi -isotropic superconducting microstructure, and is a demonstration of the enormous potential that superconducting thin film heterostructures offer for investigating the phenomenon of high temperature superconductivity.

Inam, Arun

59

Wavelength dependence of the photoresponse of a yttrium-barium-copper-oxide thin film  

NASA Astrophysics Data System (ADS)

The work explores the wavelength dependence of the photoresponse of an under-doped YBa2Cu3O7-delta thin film with a sharp resistive transition. The nature of the photoresponse is studied at a time scale of ?1 s, varying the excitation wavelength while holding sample temperature constant within the superconducting-normal transition. The bolometric portion of the photoresponse is then accounted for, and the residual non-bolometric response is compared to that found in other doping regimes and time scales. The observed wavelength dependence of the excess conductance is most likely caused by excitations into the conduction band from the filled copper bands in the CuO2 plane layer of the crystal.

Mischke, Matthew

60

Liver and kidney concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium and lead in cats  

PubMed Central

Background In order to provide new knowledge on the storage of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se) and lead (Pb) in the feline organism, we measured the concentrations of these elements in the liver, renal cortex and renal medulla, evaluating also the impact of age, sex or the occurrence of a chronic kidney disease (CKD). The element concentrations in the tissues of 47 cats (22 male; 25 female; aged between 2 months and 18 years) were measured using inductively coupled plasma mass spectrometry. Results Cu, Zn and Mn were the highest in the liver, followed by the renal cortex and the renal medulla. The Cd concentrations were lower in the renal medulla compared to the renal cortex and the liver, and Sr was higher in the renal medulla compared to the liver. The Se concentrations in the cortex of the kidneys were higher than in the medulla of the kidneys and in the liver. Higher Cd concentrations were measured in the renal cortex of female cats, while no further gender-related differences were observed. Except for Cr, Sb and Se, age-dependencies were detected for the storage of all elements. The occurrence of a CKD also affected the storage of the elements, with lower concentrations of Ba (renal medulla), Zn (renal cortex; renal medulla) and Mn (liver; renal medulla), but higher Cd concentrations (liver; renal cortex) in diseased cats. Conclusions In conclusion, the present results provide new information on the accumulation of specific elements in the feline liver and kidneys, demonstrating a dependency on age and an impaired kidney function, but not on the sex of the animals. PMID:25030305

2014-01-01

61

Concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium and lead in the equine liver and kidneys.  

PubMed

The concentrations of specific elements in the equine liver and kidneys are of practical relevance since horses are not only food-producing animals, but also partially serve as an indicator for the environmental pollution, as the basic feed includes plants like grass, grain and fruits. In this study, the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se) and lead (Pb) were measured in the liver, renal cortex and renal medulla of 21 horses (8 male; 13 female; aged between 5 months-28 years), using inductively coupled plasma mass spectrometry. Comparable Cu and Zn concentrations were detected in the liver and renal cortex, while approximately 50% lower concentrations were measured in the renal medulla. The lowest Sr, Cd and Se, but the highest Mn, Sb and Pb concentrations were measured in the liver. The Ba concentrations were comparable in the renal cortex and medulla, but lower in the liver of the horses. Gender-related differences were observed for Cd, Mn and Cr, with higher Cd concentrations in the liver, but lower Mn concentrations in the renal cortex and lower Cr concentrations in the renal medulla of female horses. Age-related differences were detected for most measured elements, however, the animal number per age-group was only low. In conclusion, the present study provides important reference data for the storage of Sr, Ba, Cd, Cu, Zn, Mn, Cr, Sb, Se and Pb in the liver and kidneys of horses, which are of practical relevance for an evaluation of the exposure of horses to these elements, either via feed or the environment. PMID:25061551

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

2014-01-01

62

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

PubMed Central

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

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

2012-01-01

63

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

ERIC Educational Resources Information Center

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)

Frieden, Earl

1974-01-01

64

Iron, Manganese and Copper Release from Synthetic Hydroxyapatite  

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

65

Blood zinc, iron, and copper levels in critically ill neonates.  

PubMed

The aim of this study is to explore the prognostic value of blood zinc, iron, and copper levels in critically ill neonates by comparing blood metal levels with the score for neonatal acute physiology (SNAP). Forty-six neonates (26 boys, 20 girls; ages ranging from 10 min to 23 days) who had been admitted to the neonatal intensive care unit of hospital and who were critically ill according to SNAP were included. Another 15 neonates (12 boys, 8 girls; ages ranging from 30 min to 24 days) who were brought to the hospital for a health checkup were included as controls. Clinical data, time in the intensive care unit, prognosis, and SNAP for critically ill neonates were recorded. Blood Cu, Zn, and Fe values were measured by inductively coupled plasma atomic emission spectrophotometry. Ill neonates were divided into extremely critical (SNAP ?10) and critical groups (1???SNAP?0.05). Fe levels were not significantly between the critical and control groups (p >0.05). In ill neonates, blood Zn and Fe concentrations in the extremely critical group were lower than in the critical group (p <0.05). Serious illness in neonates may lead to decreased Zn and Fe blood concentrations. Zn and Fe supplements may be beneficial for critically ill children. PMID:25471202

Wang, Guanghuan; Wang, Dian; Jiang, Xuewu; Yu, Xiaojun; Ma, Lian; Zhong, Jun; Feng, Xueyong

2015-03-01

66

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...

67

Copper and iron complexes catalytic for oxygen radical reactions in sweat from human athletes.  

PubMed

Sweat collected from 'explosive' and 'endurance' athletes immediately after exercise contains low molecular mass complexes of copper detectable by their ability to bind to o-phenanthroline. Concentrations of these copper complexes are much greater in arm sweat than in trunk sweat. The iron content of arm sweat, as determined by the ferrozine method, is also greater than that of trunk sweat. However, much of the iron in trunk sweat exists in a low molecular mass form that can bind to the antibiotic bleomycin, whereas the iron in arm sweat does not exist in this form. The metal complexes in human sweat are capable of stimulating the peroxidation of membrane lipids in the presence of ascorbic acid. The physiological significance of the presence of iron and copper complexes in sweat is discussed. PMID:2985297

Gutteridge, J M; Rowley, D A; Halliwell, B; Cooper, D F; Heeley, D M

1985-02-15

68

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...

69

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

E-print Network

Electronic structure of face-centered-tetragonal iron in ferromagnetic iron-copper multilayers S. J. Lloyd and R. E. Dunin-Borkowski* Department of Materials Science and Metallurgy, University of Cambridge plating, using a copper pyrophos- phate solution. Sections of the plated multilayers were ground

Dunin-Borkowski, Rafal E.

70

Iron, copper and zinc isotopic fractionation up mammal trophic chains  

NASA Astrophysics Data System (ADS)

There is a growing body of evidence that some non-traditional elements exhibit stable isotope compositions that are distinct in botanical and animal products, providing potential new tracers for diet reconstructions. Here, we present data for iron (Fe), copper (Cu) and zinc (Zn) stable isotope compositions in plants and bones of herbivores and carnivores. The samples come from trophic chains located in the Western Cape area and in the Kruger National Park in South Africa. The Fe, Cu and Zn isotope systematics are similar in both parks. However, local Cu, and possibly Zn, isotopic values of soils influence that of plants and of higher trophic levels. Between plants and bones of herbivores, the Zn isotope compositions are 66Zn-enriched by about 0.8‰ whereas no significant trophic enrichment is observed for Fe and Cu. Between bones of herbivores and bones of carnivores, the Fe isotope compositions are 56Fe-depleted by about 0.6‰, the Cu isotope compositions are 65Cu-enriched by about 1.0‰, and the Zn isotope compositions are slightly 66Zn-depleted by about 0.2‰. The isotopic distributions of the metals in the body partly explain the observed trophic isotopic systematics. However, it is also necessary to invoke differential intestinal metal absorption between herbivores and carnivores to account for the observed results. Further studies are necessary to fully understand how the Fe, Cu and Zn isotope values are regulated within the ecosystem's trophic levels, but the data already suggests significant potential as new paleodietary and paleoecological proxies.

Jaouen, Klervia; Pons, Marie-Laure; Balter, Vincent

2013-07-01

71

Electrically and magnetically tunable phase shifters based on a barium strontium titanate-yttrium iron garnet layered structure  

NASA Astrophysics Data System (ADS)

We report on the tuning of permittivity and permeability of a ferroelectric/ferromagnetic bilayer structure which can be used as a microwave phase shifter with two degrees of tuning freedom. The structure was prepared by the growth of a yttrium iron garnet (YIG) layer on a gadolinium gallium garnet substrate by liquid phase epitaxy, the growth of a barium strontium titanate (BST) layer on the YIG layer through pulsed laser deposition, and then the fabrication of a coplanar waveguide on the top of BST through e-beam evaporation and trilayer liftoff techniques. The phase shifters exhibit a differential phase shift of 38°/cm at 6 GHz through permittivity tuning under an applied electric field of ˜75 kV/cm and a static magnetic field of 1700 Oe. By tuning the permeability through the applied magnetic field we increase the differential phase shift to 52°/cm and simultaneously obtain a better match to the zero applied electric field condition, resulting in an improvement in the return loss from 22.4 to 24.9 dB. Additionally, we demonstrate the use of a lead magnesium niobate-lead titanate (PMN-PT) layer to tune the permeability of the YIG layer. This tuning relies on the piezoelectric and magnetostrictive effects of PMN-PT and YIG, respectively. Tuning of the ferromagnetic response through strain and magnetostriction as opposed to applied magnetic field can potentially pave the way for low power consumption, continuously and rapidly tunable, impedance matched phase shifters.

Leach, J. H.; Liu, H.; Avrutin, V.; Rowe, E.; Özgür, Ü.; Morkoç, H.; Song, Y.-Y.; Wu, M.

2010-09-01

72

Novel lead-free piezoelectric ceramics in the solid solution (1-x) bismuth iron oxide-barium titanate  

NASA Astrophysics Data System (ADS)

Piezoelectric materials are widely used in many areas of science and technology due to their electromechanical properties. The transformation of mechanical energy into electrical signals and vice versa based on the piezoelectric effect has led to the development of sensor devices and piezoelectric actuators used in accelerometers, pressure and vibration meters, micropositioning devices, ultrasound generators, motors etc. The most technologically important piezoelectric material is lead zirconate titanate PbZrO3-PbTiO3 (PZT), however, the commercial manufacture and application of PZT as a lead-based material represent serious health hazards. The need to reduce environmental contamination by lead-based substances has created the current drive to develop alternative lead-free piezoelectric materials. The present work describes a detailed investigation of the novel multifunctional ceramic material in a solid solution of bismuth iron oxide and barium titanate (1-x)BiFeO 3-xBaTiO3 (BFBT) with an emphasis on the room temperature piezoelectric properties and structural study. BFBT ceramics were prepared via the metal oxide solid-state preparation route. Addition of manganese oxide MnO2 increased the DC resistance by one to five orders of magnitude allowing high-field poling and piezoelectric strain measurements in Mn-modified BFBT ceramics. Piezoelectric d33 coefficients of 116 pC/N (low-field, Berlincourt) and 326 pC/N (effective, high-field) are reported for the compositions with x=0.25 and 0.33 respectively. Piezoelectric measurements using the Rayleigh law under applied large DC electric field indicated an increased low-field piezoelectric d33 coefficient to 150 pC/N (x=0.33). The DC bias is believed to stabilize the ferroclectric domain structure leading to stronger intrinsic and extrinsic contributions to the piezoelectric response in BFBT. Bright field TEM imaging confirmed formation of macroscopic domains following high field poling from initially frustrated domain state indicating the ability to induce long-range polarization order in BFBT ceramics. It is believed that the results of this work will contribute to the development of a family of lead-free piezoelectric materials based on BiFeO3-BaTiO3 system. KEYWORDS: Bismuth ferrite, Barium titanate, Lead-free, Piezoelectric ceramics, Crystal Structure

Leontsev, Serhiy

73

Chelatable iron and copper can be released from extracorporeally circulated blood during cardiopulmonary bypass.  

PubMed

During cardiopulmonary bypass surgery blood is extracorporeally oxygenated and circulated before returning to the systemic arterial circulation. Blood undergoing extracorporeal dilution and circulation is exposed to non-physiological surfaces, which cause the activation of several regulatory cascades. Cells are also subjected to damaging shear stresses. Under such conditions neutrophils can be 'activated' to release reactive oxygen intermediates such as O2- and H2O2, and other cells can release proteolytic enzymes and metalloproteins. Collectively, these events can result in the release of micromolar quantities of redox active iron and copper. Bleomycin-detectable iron and phenanthroline-detectable copper were found in two out of four mock bypass experiments. However, there was no correlation between the presence of chelatable iron and copper and the activation of neutrophils measured as elastase. PMID:7688319

Moat, N E; Evans, T E; Quinlan, G J; Gutteridge, J M

1993-08-01

74

Herbal infusions as a source of calcium, magnesium, iron, zinc and copper in human nutrition.  

PubMed

The study material consisted of five herbs: chamomile (flowers), mint (leaves), St John's wort (flowers and leaves), sage (leaves) and nettle (leaves), sourced from three producers. The calcium, magnesium, iron, zinc and copper contents were determined for both dried herb samples and prepared infusions, and the extraction rates were calculated. Mineral components were determined using atomic absorption spectrometry. Analysis showed that the contents of individual elements in herbs and infusions depended on the type of raw material, as well as on its origin. Moreover, it was found that iron penetrated the herbal infusions to the lowest degree (4.4-12.4%), while copper did so to the highest (26.7-50.7%). It is felt that in average consumption the herbal infusions are not important as calcium, magnesium, iron, zinc and copper sources in human nutrition. PMID:21916535

Suliburska, Joanna; Kaczmarek, Karolina

2012-03-01

75

Electrically and magnetically tunable phase shifters based on a barium strontium titanate-yttrium iron garnet layered structure  

E-print Network

Electrically and magnetically tunable phase shifters based on a barium strontium titanate epitaxy, the growth of a barium strontium titanate BST layer on the YIG layer through pulsed laser the use of a lead magnesium niobate-lead titanate PMN-PT layer to tune the permeability of the YIG layer

76

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

PubMed

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

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

2013-06-01

77

Some new chromogens for iron, cobalt, and copper Substituted hydrazidines and 1,2,4-triazines containing the ferroin group.  

PubMed

The spectral characteristics and solution conditions requisite for formation of the iron(II), cobalt(II), and copper(I) complexes of some newly synthesised compounds containing the ferroin functional grouping have been determined. These properties are useful for evaluation of the possible analytical effectiveness of the compounds as spectrophotometric reagents for the determination of iron, cobalt, and copper. PMID:18959951

Schilt, A A

1966-07-01

78

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2012-09-26

79

A review on biochemical roles, toxicity and interactions of zinc, copper and iron: IV. Interactions.  

PubMed

While the major impetus of most of our present knowledge of these metals emphasizes their deficiencies or toxicities, little has been done on their metabolic interactions. Such interactions acknowledge the importance of nutritional deficiencies or toxicities in the biospheres. The effect of dietary zinc supplementation on the bioavailability of copper and iron is a matter of conjecture. Likewise, further research is needed before a unifying hypothesis can be established on the effect of imbalances or interactions among copper and iron. Such mineral imbalance studies will be of value in determining their dietary requirements and in appraising circumstances in which risk to human and animal health may arise. PMID:2238446

Abdel-Mageed, A B; Oehme, F W

1990-10-01

80

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

NASA Astrophysics Data System (ADS)

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.

Zvezdanovi?, J.; Markovi?, D.

2009-09-01

81

Trace Element Status (Iron, Zinc, Copper, Chromium, Cobalt, and Nickel) in Iron-Deficiency Anaemia of Children under 3 Years  

PubMed Central

Aim. To determine trace element status and aetiologic factors for development of trace elements deficiencies in children with iron-deficiency anaemia (IDA) aged 0 to 3 years. Contingent and Methods. 30 patients of the University Hospital, Pleven, Bulgaria—I group; 48 patients of the Sumy Regional Child's Clinical Hospital, Sumy, Ukraine—II group; 25 healthy controls were investigated. Serum concentrations of iron, zinc, copper, chromium, cobalt, and nickel were determined spectrophotometrically and by atomic absorption spectrophotometry. Results. Because the obtained serum levels of zinc, copper, and chromium were near the lower reference limits, I group was divided into IA and IB. In IA group, serum concentrations were lower than the reference values for 47%, 57%, and 73% of patients, respectively. In IB group, these were within the reference values. In II group, results for zinc, cobalt, and nickel were significantly lower (P < 0.05), and results for copper were significantly higher in comparison to controls. Conclusion. Low serum concentrations of zinc, copper, cobalt, and nickel were mainly due to inadequate dietary intake, malabsorption, and micronutrient interactions in both studied groups. Increased serum copper in II group was probably due to metabolic changes resulting from adaptations in IDA. Data can be used for developing a diagnostic algorithm for IDA. PMID:24839556

Angelova, Maria Georgieva; Petkova-Marinova, Tsvetelina Valentinova; Pogorielov, Maksym Vladimirovich; Loboda, Andrii Nikolaevich; Nedkova-Kolarova, Vania Nedkova; Bozhinova, Atanaska Naumova

2014-01-01

82

Trace Element Status (Iron, Zinc, Copper, Chromium, Cobalt, and Nickel) in Iron-Deficiency Anaemia of Children under 3 Years.  

PubMed

Aim. To determine trace element status and aetiologic factors for development of trace elements deficiencies in children with iron-deficiency anaemia (IDA) aged 0 to 3 years. Contingent and Methods. 30 patients of the University Hospital, Pleven, Bulgaria-I group; 48 patients of the Sumy Regional Child's Clinical Hospital, Sumy, Ukraine-II group; 25 healthy controls were investigated. Serum concentrations of iron, zinc, copper, chromium, cobalt, and nickel were determined spectrophotometrically and by atomic absorption spectrophotometry. Results. Because the obtained serum levels of zinc, copper, and chromium were near the lower reference limits, I group was divided into IA and IB. In IA group, serum concentrations were lower than the reference values for 47%, 57%, and 73% of patients, respectively. In IB group, these were within the reference values. In II group, results for zinc, cobalt, and nickel were significantly lower (P < 0.05), and results for copper were significantly higher in comparison to controls. Conclusion. Low serum concentrations of zinc, copper, cobalt, and nickel were mainly due to inadequate dietary intake, malabsorption, and micronutrient interactions in both studied groups. Increased serum copper in II group was probably due to metabolic changes resulting from adaptations in IDA. Data can be used for developing a diagnostic algorithm for IDA. PMID:24839556

Angelova, Maria Georgieva; Petkova-Marinova, Tsvetelina Valentinova; Pogorielov, Maksym Vladimirovich; Loboda, Andrii Nikolaevich; Nedkova-Kolarova, Vania Nedkova; Bozhinova, Atanaska Naumova

2014-01-01

83

Phormidium autumnale Growth and Anatoxin-a Production under Iron and Copper Stress  

PubMed Central

Studies on planktonic cyanobacteria have shown variability in cyanotoxin production, in response to changes in growth phase and environmental factors. Few studies have investigated cyanotoxin regulation in benthic mat-forming species, despite increasing reports on poisoning events caused by ingestion of these organisms. In this study, a method was developed to investigate changes in cyanotoxin quota in liquid cultures of benthic mat-forming cyanobacteria. Iron and copper are important in cellular processes and are well known to affect growth and selected metabolite production in cyanobacteria and algae. The effect of iron (40–4000 ?g L?1) and copper (2.5–250 ?g L?1) on growth and anatoxin-a quota in Phormidium autumnale was investigated in batch culture. These concentrations were chosen to span those found in freshwater, as well as those previously reported to be toxic to cyanobacteria. Anatoxin-a concentrations varied throughout the growth curve, with a maximum quota of between 0.49 and 0.55 pg cell?1 measured within the first two weeks of growth. Growth rates were significantly affected by copper and iron concentrations (P < 0.0001); however, no statistically significant difference between anatoxin-a quota maxima was observed. When the iron concentrations were 800 and 4000 ?g L?1, the P. autumnale cultures did not firmly attach to the substratum. At 250 ?g L?1 copper or either 40 or 4000 ?g L?1 iron, growth was suppressed. PMID:24351714

Harland, Francine M. J.; Wood, Susanna A.; Moltchanova, Elena; Williamson, Wendy M.; Gaw, Sally

2013-01-01

84

Rates of dissolution of solid iron, cobalt, nickel, and silicon in liquid copper and diffusion rate of iron from liquid Cu-Fe alloy into liquid copper  

Microsoft Academic Search

Consideration is given to the previously reported data on the observed dissolution rate of the vertical peripheries of cylindrical\\u000a iron, cobalt, and nickel in liquid copper at temperatures in the range of 1468 to 1653 K under natural convection. The observed\\u000a steady-state rate is close to the rate calculated from an equation expressed in terms of the activity of solute

Reiichi Ohno

1986-01-01

85

Effects of Copper and Austempering on Corrosion Behavior of Ductile Iron in 3.5 Pct Sodium Chloride  

NASA Astrophysics Data System (ADS)

Although alloying and heat treatments are common industrial practices to obtain ductile irons with desired mechanical properties, related information on how the two practices affect corrosion behavior is scarce. In this study, two ductile irons—with and without 1 wt pct copper addition—were austempered to obtain austempered ductile irons (ADIs). Polarization tests and salt spray tests were conducted to explore how both copper-alloying and austempering heat treatments influenced the corrosion behavior of ductile irons. The results showed that the corrosion resistance of 1 wt pct copper-alloyed ductile iron was better than that of the unalloyed one, while ADI had improved corrosion resistance compared with the as-cast. In particular, the ductile iron combined with the copper-alloying and austempering treatments increased the corrosion inhibition efficiency up to 84 pct as tested in 3.5 wt pct NaCl solution.

Hsu, Cheng-Hsun; Lin, Kuan-Ting

2013-10-01

86

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

PubMed

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

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

87

Response of zinc, iron and copper status parameters to supplementation with zinc or zinc and iron in women  

SciTech Connect

Supplementation with zinc at levels available over-the-counter may compromise iron or copper status. This study examined the effects of zinc(50mg/day) or zinc and iron(50 mg each/day) on 18 women aged 25-40. Subjects were matched on initial levels of serum ferritin(SF) and erythrocyte superoxide dismutase(ESOD) and randomly assigned to Group Z (zinc) or F-Z (iron and zinc). The following were measured pretreatment and after 6 and 10 weeks treatment: serum zinc (BZ), salivary sediment zinc (SSZ), hemoglobin (Hgb), hematocrit (Hct), SF, serum ceruloplasmin (Cp) and ESOD. Effects of treatment and weeks of treatment on changes from initial blood and saliva levels were analyzed using AOV. BZ increased (P=0.0144) and ESOD decreased (P=0.0001) with weeks of treatment. Differences due to treatment are presented. No effects were noted on Hgb, Hct or Cp. Intakes of zinc supplements at about 4X RDA appear to decrease copper(ESOD) and iron(SF) status. Use of iron w/zinc may be protective for FE but not Cu, and may compromise zinc (SSZ) status.

Yadrick, K.; Kenney, M.A.; Winterfeldt, E.

1986-03-05

88

Electrokinetic Copper and Iron Migration in Anaerobic Granular Sludge  

Microsoft Academic Search

The application of low-level direct electric current (0.15 mA cm?2) as an electrokinetic technique to treat copper-contaminated mesophilic anaerobic granular sludge was investigated. The sludge was obtained from a full scale UASB reactor treating paper-mill wastewater and was artificially contaminated by Cu(NO3)2 or CuEDTA2? with initial copper concentrations of 1000 mg . kg?1 wet sludge. The effect of different electrokinetic

Jurate Virkutyte; Mika Sillanpää; Piet Lens

2006-01-01

89

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

USGS Publications Warehouse

Diel variations in the concentrations of a number of constituents have the potential to substantially affect the appropriate sampling regimen in acidic streams. Samples taken once during the course of the day cannot adequately reflect diel variations in water quality and may result in an inaccurate understanding of biogeochemical processes, ecological conditions, and of the threat posed by the water to human health and the associated wildlife. Surface water and groundwater affected by acid drainage were sampled every 60 to 90. min over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, near Hegeler, Illinois. Diel variations related to water quality in the aquifer were not observed in groundwater. Diel variations were observed in the temperature, pH, and concentration of dissolved oxygen, nitrite, barium, iron, lead, vanadium, and possibly uranium in surface water. Temperature, dissolved oxygen, nitrite, barium, lead, and uranium generally attained maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally attained minimum values during the afternoon and maximum values during the night. Concentrations of dissolved oxygen were affected by the intensity of photosynthetic activity and respiration, which are dependent upon insolation. Nitrite, an intermediary in many nitrogen reactions, may have been formed by the oxidation of ammonium by dissolved oxygen and converted to other nitrogen species as part of the decomposition of organic matter. The timing of the pH cycles was distinctly different from the cycles found in Midwestern alkaline streams and likely was the result of the photoreduction of Fe3+ to Fe 2+ and variations in the intensity of precipitation of hydrous ferric oxide minerals. Diel cycles of iron and vanadium also were primarily the result of variations in the intensity of precipitation of hydrous ferric oxide minerals. The diel variation in the concentrations of lead, uranium, and barium may have been affected by competition with Fe+2 for sorption sites on hydrous ferric oxide minerals. ?? 2010.

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

2011-01-01

90

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

PubMed

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

Primc, D; Makovec, D

2015-02-14

91

Effect of biogenic iron species and copper ions on the reduction of carbon tetrachloride under iron-reducing conditions  

Microsoft Academic Search

In this study, the cell-mediated and abiotic reduction of carbon tetrachloride (CCl4) by biogenic iron species produced from the reductive dissolution of ferrihydrite in the presence of Geobacter sulfurreducens and copper ions (Cu(II)) were investigated. 9,10-Anthraquinone-2,6-disulfonate (AQDS), serving as a surrogate of natural organic matters and an electron shuttling compound, was added to enhance the efficiency of biological reduction of

R. A. Maithreepala; Ruey-an Doong

2008-01-01

92

Hexavalent chromium removal from near natural water by copper-iron bimetallic particles.  

PubMed

The reduction of hexavalent chromium (Cr(VI)) by zero-valent iron (ZVI) is self-inhibiting in near natural groundwater because insulating Fe(III)-Cr(III) (oxy)hydroxide film forms on the ZVI surface during the reaction. This study tries to overcome this deficiency by coating the surface of ZVI with copper to form copper-iron bimetallic particles. The Cr(VI) removal rate by ZVI rose significantly after the copper coating was applied. The copper loading needed for enhancing Cr(VI) removal was much higher than that needed for enhancing removal of chlorinated organic compounds or other oxidative contaminants, because of the higher oxidation potential of Cr(VI). The results of X-ray photoelectron spectroscopy (XPS) indicate that coating copper onto the surface of ZVI can not only increase the deepness of the oxidation film but also increase the oxidation state of iron in the film. This phenomenon means higher Cr(VI) removal capacity per unit weight of ZVI. PMID:20350740

Hu, Ching-Yao; Lo, Shang-Lien; Liou, Ya-Hsuan; Hsu, Ya-Wen; Shih, Kaimin; Lin, Chin-Jung

2010-05-01

93

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

Microsoft Academic Search

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

Cornelia Richardson-Boedler

2007-01-01

94

Gas tungsten arc welding of nickel-copper to nickel-chromium-iron. Welding procedure specification  

Microsoft Academic Search

Procedure WPS-2303-ASME-3 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for gas tungsten arc welding of nickel-copper N04400 (P-42) to nickel-chromium-iron N06600 (P-43), in thickness of 0.035 to 0.432 inch; filler metal is ERNiCu-7 (F-42); shielding gas is argon.

C. H. Wodtke; D. R. Frizzell; W. A. Plunkett

1985-01-01

95

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

E-print Network

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

Bernhard, Stefan

96

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...

97

Gas tungsten arc welding of nickel-copper to nickel-chromium-iron. Welding procedure specification  

SciTech Connect

Procedure WPS-2303-ASME-3 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for gas tungsten arc welding of nickel-copper N04400 (P-42) to nickel-chromium-iron N06600 (P-43), in thickness of 0.035 to 0.432 inch; filler metal is ERNiCu-7 (F-42); shielding gas is argon.

Wodtke, C.H.; Frizzell, D.R.; Plunkett, W.A.

1985-08-01

98

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

SciTech Connect

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.

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

2003-01-01

99

Barium enema  

MedlinePLUS

Barium enema is a special x-ray of the large intestine, which includes the colon and rectum. ... to a bag that holds a liquid containing barium sulfate. This is a contrast material that highlights ...

100

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

PubMed Central

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

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

101

Computational Benchmarking in Biomimetic Nickel, Copper, and Iron Complexes  

E-print Network

in the absence of experimental data. In this dissertation, such techniques serve to elucidate the observed reactivity or electronic character of both nickel and copper bound in square planar N?S? ligand fields, and of {Fe(NO)?} units, respectively. Nickel...

Brothers, Scott Michael

2012-02-14

102

Effects of dietary carbohydrate on iron metabolism and cytochrome oxidase activity in copper-deficient rats  

SciTech Connect

The effects of dietary carbohydrate on the metabolism of iron and the activity of cytochrome oxidase were examined in Cu-deficient and Cu-adequate rats. Male rats (n = 36) were fed one of six diets which varied in copper level (Cu-: < 0.6 ppm or Cu+: 8.2 ppm) and carbohydrate type (cornstarch, sucrose or fructose). After 31 days, Cu- rats had 50% more iron in the liver and 38, 30 and 18% less iron in the tibia, spleen and kidneys, respectively, than Cu+ rats. The activity of cytochrome oxidase in the bone marrow, heart, and liver were 59%, 51%, and 43%, respectively, of the levels in Cu/sup +/ rats. The type of dietary carbohydrate significantly affected the development of anemia during copper deficiency. Cu-rats fed cornstarch, sucrose or fructose had hematocrit levels which were 92, 83 or 73%, respectively, of Cu+ rats. Similarly, the levels of iron in the tibias of Cu- rats fed cornstarch, sucrose or fructose were 69, 66 or 54%, respectively, of Cu+ rats. The hematocrit levels of Cu- rats were positively correlated to both tibia iron levels (r = 0.64, p < 0.005) and liver cytochrome oxidase activities (r = 0.50, p < 0.05). Thus, it appears that changes in the metabolism of iron may be involved with the development of anemia in Cu- rats fed fructose or sucrose.

Johnson, M.A.; Henderson, J.

1986-03-01

103

Magnetic effects of hydrothermal alteration in porphyry copper and iron-oxide copper-gold systems: A review  

NASA Astrophysics Data System (ADS)

Magnetic anomaly patterns can be used as a tool for mapping lithology, metamorphic zones and hydrothermal alteration systems, as well as identifying structures that may control passage of magmas or hydrothermal fluids associated with mineralisation. Reliable geological interpretation of mineralised systems requires an understanding of the magmatic, metamorphic and hydrothermal processes that create, alter and destroy magnetic minerals in rocks. Predictive magnetic exploration models for porphyry copper and iron oxide copper-gold (IOCG) deposits can be derived from standard geological models by integrating magnetic petrological principles with petrophysical data, deposit descriptions, and modelling of observed magnetic signatures of these deposits. Even within a particular geological province, the magnetic signatures of similar deposits may differ substantially, due to differences in the local geological setting. Searching for “look-alike” signatures of a known deposit is likely to be unrewarding unless pertinent geological factors are taken into account. These factors include the tectonic setting and magma type, composition and disposition of host rocks, depth of emplacement and post-emplacement erosion level, depth of burial beneath younger cover, post-emplacement faulting and tilting, remanence effects contingent on ages of intrusion and alteration, and metamorphism. Because the effects of these factors on magnetic signatures are reasonably well understood, theoretical magnetic signatures appropriate for the local geological environment can qualitatively guide exploration and make semiquantitative predictions of anomaly amplitudes and patterns. The predictive models also allow detectability of deposit signatures to be assessed, for example when deposits are buried beneath a considerable thickness of nonmagnetic overburden, are covered by highly magnetic heterogeneous volcanic rocks, or there is a strong regional magnetic gradient. This paper reviews the effects of hydrothermal alteration on magnetic properties and magnetic signatures of porphyry copper and iron oxide copper-gold systems and presents examples of predictive magnetic exploration models, and their predicted signatures, in various geological circumstances.

Clark, David A.

2014-06-01

104

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

PubMed

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

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

2009-02-18

105

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

NASA Astrophysics Data System (ADS)

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.

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

2009-02-01

106

Effects of endogenous neurotoxin quinolinic acid on reactive oxygen species production by Fenton reaction catalyzed by iron or copper  

PubMed Central

The tryptophan metabolite, quinolinic (2,3-pyridinedicarboxylic) acid, is known as an endogenous neurotoxin. Quinolinic acid can form coordination complexes with iron or copper. The effects of quinolinic acid on reactive oxygen species production in the presence of iron or copper were explored by a combination of chemical assays, classical site-specific and ascorbic acid-free variants of the deoxyribose degradation assay, and mass spectrometry (ESI–MS). Quinolinic acid showed evident antioxidant activity in chemical assays, but the effect was more pronounced in the presence of copper as transition metal catalyst than in presence of iron. Nano-ESI–MS confirmed the ability of quinolinic acid to form coordination complexes with iron(II) or copper(II) and quinolinic acid stability against oxidative attack by hydroxyl radicals. The results illustrate a highly milieu-dependent quinolinic acid chemistry when it enters reactions as competitive ligand.

Kubicova, Lenka; Hadacek, Franz; Weckwerth, Wolfram; Chobot, Vladimir

2015-01-01

107

Content of total iron, copper and manganese in liver of animals during hypokinesia, muscle activity and process of recovery  

NASA Technical Reports Server (NTRS)

It is shown that the content of total iron, copper and manganese in the liver of animals is altered depending on the intensity and duration of their swimming. Hypodynamia for 7 days does not alter the concentration of iron, but sufficiently increases the content of copper and manganese. The barometric factor effectively influences the maintenance of constancy in the content of microelements accumulated in the liver after intensive muscle activity.

Potapovich, G. M.; Taneyeva, G. V.; Uteshev, A. B.

1980-01-01

108

The influence of selected antihypertensive drugs on zinc, copper, and iron status in spontaneously hypertensive rats.  

PubMed

Mineral homeostasis in hypertensive patients may be affected by hypotensive drugs. The aim of this study was to assess the influence of selected antihypertensive drugs on mineral homeostasis in a rat model of hypertension. Eight-week-old male spontaneously hypertensive rats (SHRs) were treated with perindopril, metoprolol, indapamide, amlodipine, or no drug for 45 days. In another experiment, the SHRs were treated with indapamide or amlodipine in the presence of zinc and copper gluconate supplement. Lipids, glucose, and insulin levels along with superoxide dismutase and catalase activities were assayed in serum. Iron, zinc, and copper concentrations in serum, erythrocytes, and tissues were determined using the flame atomic absorption spectrometry. Blood pressure was measured using a tail-cuff plethysmograph. Treatment with indapamide and amlodipine was found to significantly lower zinc levels in serum, erythrocytes, livers, and spleens of the SHRs, as well as copper levels in the kidneys, compared with the control no-drug group. A markedly higher concentration of glucose was found in the indapamide-treated rats. Supplementing the indapamide-treated SHRs with zinc and copper gluconate resulted in a significant decrease in both systolic and diastolic blood pressure, and also lowered serum glucose and triglyceride concentrations and HOMA (homeostasis model assessment-insulin resistance) values. The results show that indapamide and amlodipine disturb zinc and copper homeostasis in SHRs. Supplementation with zinc and copper restores mineral homeostasis in SHRs treated with indapamide and amlodipine, and also corrects metabolic imbalances while improving the antihypertensive efficiency of indapamide. PMID:24927993

Suliburska, Joanna; Bogdanski, Pawe?; Jakubowski, Hieronim

2014-09-01

109

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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....

2013-11-01

110

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

PubMed Central

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

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

2009-01-01

111

PICOSECOND X-RAY DIFFRACTION FROM LASER-SHOCKED COPPER AND IRON  

E-print Network

PICOSECOND X-RAY DIFFRACTION FROM LASER-SHOCKED COPPER AND IRON J.S. Wark, J.F. Belak, G.W. Collins, J.D. Colvin, H.M. Davies, M. Duchaineau, J.H. Eggert, T.C. Germann, J. Hawreliak, A. Higginbotham, B Compression of Condensed Matter - 2005, edited by M. D. Furnish, M. Elert, T. P. Russell, and C. T. White

Meyers, Marc A.

112

Copper, Chromium, Manganese, Iron, Nickel, and Zinc Levels in Biological Samples of Diabetes Mellitus Patients  

Microsoft Academic Search

There is accumulating evidence that the metabolism of several trace elements is altered in diabetes mellitus and that these\\u000a nutrients might have specific roles in the pathogenesis and progress of this disease. The aim of present study was to compare\\u000a the level of essential trace elements, chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn) in

Tasneem Gul Kazi; Hassan Imran Afridi; Naveed Kazi; Mohammad Khan Jamali; Mohammad Bilal Arain; Nussarat Jalbani; Ghulam Abbas Kandhro

2008-01-01

113

Evaluation of trace elements iron, zinc, copper and lead In the diet of female university students  

Microsoft Academic Search

Food consumption of 50 female students in Universiti Kebangsaan Malaysia was recorded for 7 days. Foods and drinks most frequently consumed were selected for analysis of iron, zinc, copper and lead content. The mean daily intakes of energy, protein, carbohydrate and fat among the students are 6.5±1.4 MJ (1550±335 kcal), 59.8±18.5g. 227. 1±54.6 g and 46.0±11.5 g respectively. This diet

Zawiah Hashim

114

Valences of iron and copper in coral skeleton: X-ray absorption spectroscopy analysis  

Microsoft Academic Search

Synchrotron-based X-ray absorption spectroscopy (XAS) indicates that both iron and copper are present in their normal fully oxidized states, Fe(III) and Cu(II), in the aragonite (CaCO3, orthorhombic) skeletons of scleractinian reef corals. The Fe(III) may substitute for Ca(II) at its structural sites; alternatively, it may be present in clay or other detritus incorporated in the coral skeleton. The XAS-determined Cu(II)

Nicholas E. Pingitore Jr.; Arturo Iglesias; Allison Bruce; Farrel Lytle; Gerard M. Wellington

2002-01-01

115

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

PubMed Central

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

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

116

Heterogeneous irradiation-induced copper precipitation in ferritic iron–copper model alloys  

Microsoft Academic Search

The mechanism at the origin of the formation of nano-copper-enriched clusters in the ferritic matrix of nuclear reactor pressure vessel steel is not yet fully understood. In this work, specific irradiation experiments were carried out using 3MeV electron and 150keV Fe+ ions in order to point out the effect of (i) free migrating point defects (produced as Frenkel pairs with

Philippe Pareige; Bertrand Radiguet; Alain Barbu

2006-01-01

117

Heterogeneous irradiation-induced copper precipitation in ferritic iron copper model alloys  

NASA Astrophysics Data System (ADS)

The mechanism at the origin of the formation of nano-copper-enriched clusters in the ferritic matrix of nuclear reactor pressure vessel steel is not yet fully understood. In this work, specific irradiation experiments were carried out using 3 MeV electron and 150 keV Fe + ions in order to point out the effect of (i) free migrating point defects (produced as Frenkel pairs with 3 MeV electron) and (ii) the ballistic mixing and partial recombination of atoms due to displacement cascades (produced with ions). In both cases the irradiation-induced phase transformation were characterized using the 3D atom probe technique. The time-dependant evolution of the point defect population was computed using the cluster dynamic code (MFPVIC) developed at CEA. The combination of experiment and simulation shows that, in low copper (<0.1 at.% Cu) FeCu alloys, heterogeneous irradiation-induced copper precipitation is taking place on point defects clusters generated by 20-30 keV displacement cascades.

Pareige, Philippe; Radiguet, Bertrand; Barbu, Alain

2006-06-01

118

Property and microstructural nonuniformity in the yttrium-barium-copper-oxide superconductor determined from electrical, magnetic, and ultrasonic measurements. Ph.D. Thesis - Case Western Reserve Univ.  

NASA Technical Reports Server (NTRS)

The purpose of this dissertation was the following: (1) to characterize the effect of pore fraction on a comprehensive set of electrical and magnetic properties for the yttrium-barium-copper-oxide (YBCO) high temperature ceramic superconductor; and (2) to determine the viability of using a room-temperature, nondestructive characterization method to aid in the prediction of superconducting (cryogenic) properties. The latter involved correlating ultrasonic velocity measurements at room temperature with property-affecting pore fraction and oxygen content variations. The use of ultrasonic velocity for estimating pore fraction in YBCO is presented, and other polycrystalline materials are reviewed, modeled, and statistically analyzed. This provides the basis for using ultrasonic velocity to interrogate microstructure. The effect of pore fraction (0.10-0.25) on superconductor properties of YBCO samples was characterized. Spatial (within-sample) variations in microstructure and superconductor properties were investigated, and the effect of oxygen content on elastic behavior was examined. Experimental methods used included a.c. susceptibility, electrical, and ultrasonic velocity measurements. Superconductor properties measured included transition temperature, magnetic transition width, transport and magnetic critical current density, magnetic shielding, a.c. loss, and sharpness of the voltage-current characteristics. An ultrasonic velocity image constructed from measurements at 1mm increments across a YBCO sample revealed microstructural variations that correlated with variations in magnetic shielding and a.c. loss behavior. Destructive examination using quantitative image analysis revealed pore fraction to be the varying microstructural feature.

Roth, Don J.

1991-01-01

119

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

PubMed Central

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

Zhao, Lu; Xia, Zhidan; Wang, Fudi

2014-01-01

120

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

PubMed

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

Zhao, Lu; Xia, Zhidan; Wang, Fudi

2014-01-01

121

PICOSECOND X-RAY DIFFRACTION FROM LASER-SHOCKED COPPER AND IRON  

SciTech Connect

In situ X-ray diffraction allows the determination of the structure of transient states of matter. We have used laser-plasma generated X-rays to study how single crystals of metals (copper and iron) react to uniaxial shock compression. We find that copper, as a face-centered-cubic material, allows rapid generation and motion of dislocations, allowing close to hydrostatic conditions to be achieved on sub-nanosecond timescales. Detailed molecular dynamics calculations provide novel information about the process, and point towards methods whereby the dislocation density might be measured during the passage of the shock wave itself. We also report on recent experiments where we have obtained diffraction images from shock-compressed single-crystal iron. The single crystal sample transforms to the hcp phase above a critical pressure, below which it appears to be uniaxially compressed bcc, with no evidence of plasticity. Above the transition threshold, clear evidence for the hcp phase can be seen in the diffraction images, and via a mechanism that is also consistent with recent multi-million atom molecular dynamics simulations that use the Voter-Chen potential. We believe these data to be of import, in that they constitute the first conclusive in situ evidence of the transformed structure of iron during the passage of a shock wave.

Wark, J S; Belak, J F; Collins, G W; Colvin, J D; Davies, H M; Duchaineau, M; Eggert, J H; Germann, T C; Hawreliak, J; Higginbotham, A; Holian, B L; Kadau, K; Kalantar, D H; Lomdahl, P S; Lorenzana, H E; Meyers, M A; Remington, B A; Rosolankova, K; Rudd, R E; Schneider, M S; Sheppard, J; Stolken, J S

2005-08-23

122

Picosecond X-Ray Diffraction from Laser-Shocked Copper and Iron  

SciTech Connect

In situ X-ray diffraction allows the determination of the structure of transient states of matter. We have used laser-plasma generated X-rays to study how single crystals of metals (copper and iron) react to uniaxial shock compression. We find that copper, as a face-centred-cubic material, allows rapid generation and motion of dislocations, allowing close to hydrostatic conditions to be achieved on sub-nanosecond timescales. Detailed molecular dynamics calculations provide novel information about the process, and point towards methods whereby the dislocation density might be measured during the passage of the shock wave itself. We also report on recent experiments where we have obtained diffraction images from shock-compressed single-crystal iron. The single crystal sample transforms to the hcp phase above a critical pressure, below which it appears to be uniaxially compressed bcc, with no evidence of plasticity. Above the transition threshold, clear evidence for the hcp phase can be seen in the diffraction images, and via a mechanism that is also consistent with recent multi- million atom molecular dynamics simulations that use the Voter- Chen potential. We believe these data to be of import, in that they constitute the first conclusive in situ evidence of the transformed structure of iron during the passage of a shock wave.

Wark, J. S.; Hawreliak, J.; Higginbotham, A.; Rosolankova, K.; Sheppard, J. [Department of Physics, Clarendon Laboratory, Parks Road, University of Oxford, OX1 3PU (United Kingdom); Belak, J. F.; Collins, G. W.; Colvin, J. D.; Duchaineau, M.; Eggert, J. H.; Kalantar, D. H.; Lorenzana, H. E.; Remington, B. A.; Rudd, R. E.; Stolken, J. S. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Davies, H. M. [AWE Aldermaston, Reading (United Kingdom); Germann, T. C.; Holian, B. L.; Kadau, K.; Lomdahl, P. S. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)] (and others)

2006-07-28

123

In-situ formation of barium ferrite in iron-doped “tetragonal tungsten bronze”: Elaboration of room temperature multiferroic composites  

Microsoft Academic Search

Recent studies of ceramics of formula Ba2LnFeNb4O15 (Ln=rare earth) with the “tetragonal tungsten bronze” (TTB) structure have correlated their room temperature multiferroics properties to the occurrence of barium ferrite parasitic phases. This work presents the elaboration of Ba2LaFeNb4O15 and Ba2EuFeNb4O15 composite samples with an excess of hematite in the TTB nominal composition. The influence of crystal-chemistry on the phase content

E. Castel; M. Josse; F. Roulland; D. Michau; L. Raison; M. Maglione

2009-01-01

124

Copper, iron and zinc absorption, retention and status of young women fed vitamin B-6 deficient diets  

SciTech Connect

A study was conducted in young women to determine the effect of vitamin B-6 deficient diets on copper, iron and zinc metabolism. Young women were confined to a metabolic research unit for 84 and 98 days. They were fed a vitamin B-6 deficient formula diet initially, followed by food diet containing four increasing levels of vitamin B-6. Copper, iron and zinc absorption, retention and status were determined at intervals throughout the study. Absorption was determined using the stable isotopes {sup 65}Cu, {sup 54}Fe, and {sup 67}Zn. Status was based on serum copper and zinc, hemoglobin, hematocrit and mean corpuscular volume. Copper absorption averaged 18 {plus minus} 1% during vitamin B-6 depletion, significantly lower than 24 {plus minus} 1% during repletion, but serum copper was not affected and balance was positive. Iron absorption was not impaired significantly by vitamin B-6 deficient diets, but status declined during the depletion period. Zinc absorption averaged 40 {plus minus} 2% during depletion and 27 {plus minus} 2% during repletion. Zinc absorption and retention were significantly greater during vitamin B-6 depletion, but serum zinc declined suggesting the absorbed zinc was not available for utilization. The results suggest that vitamin B-6 depletion of young women may inhibit copper absorption, affect iron status and alter zinc metabolism. The effects of vitamin B-6 depletion differ markedly among these elements.

Turnlund, J.R.; Keyes, W.R.; Hudson, C.A.; Betschart, A.A.; Kretsch, M.J.; Sauberlich, H.E. (USDA/ARS, San Francisco, CA (United States) Western Regional Research Center, Albany, CA (United States))

1991-03-11

125

Determination of copper, scandium, molybdenum, tin, lead, and iron group elements in lunar surface materials  

NASA Technical Reports Server (NTRS)

Distribution regularities of copper, scandium, molybdenum, tin, lead, and iron group elements were investigated in basaltoid rocks of lunar and terrestrial origin. Samples of various regolith zones taken in the area of the Sea of Fertility were analyzed, along with samples of basic and ultrabasic rocks of the East African Rift for their content of the trace admixtures listed. Data obtained on the abundance of copper, scandium, molybdenum, tin, lead, cobalt, nickel, chromium, and vanadium in Luna 16 lunar surface material were compared with the abundance of these elements in samples of lunar rocks returned by Apollo 11, Apollo 12, and Apollo 14, with the exception of scandium; its content in the latter samples was considerably higher.

Pavlenko, L. I.; Simonova, L. V.; Karyakin, A. V.

1974-01-01

126

Iron and Copper Act Synergistically To Delay Anaerobic Growth of Bacteria  

PubMed Central

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

Bird, Lina J.; Coleman, Maureen L.

2013-01-01

127

Relationship between Paratuberculosis and the microelements Copper, Zinc, Iron, Selenium and Molybdenum in Beef Cattle  

PubMed Central

To study the deficiency of minerals and its relationship with Paratuberculosis, blood, serum, and fecal samples were obtained from 75 adult bovines without clinical symptoms of the disease and from two bovines with clinical symptoms of the disease, from two beef herds with a previous history of Paratuberculosis in the Province of Buenos Aires, Argentina. Serum samples were processed by ELISA and feces were cultured in Herrolds medium. Copper, zinc and iron in serum were quantified by spectrophotometry and selenium was measured by the activity of glutathione peroxidase. We also determined copper, zinc, iron and molybdenum concentrations in pastures and the concentration of sulfate in water. Mycobacterium avium subsp paratuberculosis (Map) was isolated from 17.3% of fecal samples of asymptomatic animals and from the fecal samples from the two animals with clinical symptoms. All the Map-positive animals were also ELISA-positive or suspect, and among them, 84.6% presented low or marginal values of selenium and 69.2% presented low or marginal values of copper. The two animals with clinical symptoms, and isolation of Map from feces and organs were selenium-deficient and had the lowest activity of glutathione peroxidase of all the animals from both herds. All the animals negative to Map in feces and negative to ELISA had normal values of Se, while 13.8% of animals with positive ELISA or suspect and culture negative presented low levels of Se. Half of the animals that were negative both for ELISA and culture in feces were deficient in copper but none of them presented low values of selenium. The content of molybdenum and iron in pasture was high, 2.5 ppm and 1.13 ppm in one herd and 2.5 ppm and 2.02 ppm in the other, respectively, whereas the copper:molybdenum ratio was 1.5 and 5.2, respectively. These results do not confirm an interaction between imbalances of the micronutrients and clinical Paratuberculosis, but show evidence of the relationship between selenium deficiencies in animals with Map infection and ELISA positive results. PMID:24159298

Paolicchi, F.; Perea, J.; Cseh, S.; Morsella, C.

2013-01-01

128

Sorption concentration of copper, lead, and iron on carriers modified by 8-hydroxyquinoline and its derivatives  

Microsoft Academic Search

Sorption of copper, lead, and iron ions on carriers (silochrome S-120, anion exchanger AB-17, enterosgel, polysorb) noncovalently\\u000a modified by 8-hydroxynoline, 5,7-dibrom-8-hydroxyquinoline, and 8-hydroxynoline-5-sulfo-acid has been studied. Optimal sorption\\u000a conditions have been found. The determination is not impeded by a 103-fold excess of potassium, natrium, calcium and magnesium. The methods have been tested on water and soil samples from Saransk\\u000a city.

V. M. Ivanov; E. V. Antonova; E. N. Uskova

2009-01-01

129

Interaction between anemia and blood levels of iron, zinc, copper, cadmium and lead in children  

Microsoft Academic Search

Objective  Anemia is a widespread problem among infants and children in many parts of the world, and it is often associated with some\\u000a trace elements (iron, zinc, copper) and heavy metals (cadmium and lead). Aim of this study was to investigate the relationship\\u000a between anemia and these elements.\\u000a \\u000a \\u000a \\u000a Methods  This research was performed on 256 children (mean age 6.8 ± 0.2) living

Sebahat Turgut; Aziz Polat; Murat Inan; Günfer Turgut; Gülten Emmungil; Mevlüt Bican; Tugrul Yasin Karakus; Osman Genç

2007-01-01

130

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

PubMed Central

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

Mathews, Salima; Hans, Michael

2013-01-01

131

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

NASA Technical Reports Server (NTRS)

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.

Wheeler, D. R.

1975-01-01

132

Dry Sliding Wear of a Powder Metallurgy Copper-based Metal Matrix Composite Reinforced with Iron Aluminide Intermetallic Particles  

Microsoft Academic Search

In the present study, dry sliding wear behavior of a powder metallurgy copper alloy matrix composite containing iron aluminide (Fe3Al) intermetallic particles was investigated using a pin-on-disk machine. A sintered copper alloy (Cu—90%, Sn—10%) was used as matrix. Reinforcement Fe3Al particles were prepared by mechanical alloying (42 h) and used as reinforcement (10 and 20 vol%) in the matrix. The

K. Venkateswaran; M. Kamaraj; K. Prasad Rao

2007-01-01

133

Friction and transfer of copper, silver, and gold to iron in the presence of various adsorbed surface films  

NASA Technical Reports Server (NTRS)

Sliding friction experiments were conducted with the noble metals copper, silver, and gold and two binary alloys of these metals contacting iron in the presence of various adsorbates including, oxygen, methyl mercaptan, and methyl chloride. A pin on disk specimen configuration was used with a load of 100 grams, sliding velocity of 60 mm/min; at 25 C with the surfaces saturated with the adsorbates. Auger emission spectroscopy was used to monitor surface films. Results of the experiments indicate that friction and transfer characteristics are highly specific with respect to both the noble metal and surface film present. With all three metals and films transfer of the noble metal to iron occurred very rapidly. With all metals and films transfer of the noble metal to iron continuously increased with repeated passes except for silver and copper sliding on iron sulfide.

Buckley, D. H.

1979-01-01

134

The proteome of copper, iron, zinc, and manganese micronutrient deficiency in Chlamydomonas reinhardtii.  

PubMed

Trace metals such as copper, iron, zinc, and manganese play important roles in several biochemical processes, including respiration and photosynthesis. Using a label-free, quantitative proteomics strategy (MS(E)), we examined the effect of deficiencies in these micronutrients on the soluble proteome of Chlamydomonas reinhardtii. We quantified >10(3) proteins with abundances within a dynamic range of 3 to 4 orders of magnitude and demonstrated statistically significant changes in ~200 proteins in each metal-deficient growth condition relative to nutrient-replete media. Through analysis of Pearson's coefficient, we also examined the correlation between protein abundance and transcript abundance (as determined via RNA-Seq analysis) and found moderate correlations under all nutritional states. Interestingly, in a subset of transcripts known to significantly change in abundance in metal-replete and metal-deficient conditions, the correlation to protein abundance is much stronger. Examples of new discoveries highlighted in this work include the accumulation of O(2) labile, anaerobiosis-related enzymes (Hyd1, Pfr1, and Hcp2) in copper-deficient cells; co-variation of Cgl78/Ycf54 and coprogen oxidase; the loss of various stromal and lumenal photosynthesis-related proteins, including plastocyanin, in iron-limited cells; a large accumulation (from undetectable amounts to over 1,000 zmol/cell) of two COG0523 domain-containing proteins in zinc-deficient cells; and the preservation of photosynthesis proteins in manganese-deficient cells despite known losses in photosynthetic function in this condition. PMID:23065468

Hsieh, Scott I; Castruita, Madeli; Malasarn, Davin; Urzica, Eugen; Erde, Jonathan; Page, M Dudley; Yamasaki, Hiroaki; Casero, David; Pellegrini, Matteo; Merchant, Sabeeha S; Loo, Joseph A

2013-01-01

135

Dynamic properties of edge dislocations decorated by interstitial dislocation loops in alpha-iron and copper.  

SciTech Connect

Clusters of self-interstitial atoms (SIAs) in the form of parallel crowdions are created directly in high-energy displacement cascades produced in metals by neutron irradiation. They are equivalent to small perfect dislocation loops and, in isolation in pure metals, undergo fast thermally-activated glide in the direction of their Burgers vector. Their strain field and ability to glide allows long-range interaction with other extended defects. Indeed, dislocations decorated by dislocation loops are commonly observed after neutron irradiation. Dislocations gliding under applied stress also encounter these mobile defects. These effects influence mechanical properties and require further investigation. This paper presents results from an atomic-scale study of copper and {alpha}-iron at either 0 K or 300 K. Loop drag and breakaway effects are investigated for an edge dislocation under applied stress interacting with a row of SIA loops below its glide plane. The maximum speed at which a loop is dragged is lower in copper than iron, and the applied stress at which this occurs is also lower. These differences in the dynamics of cluster-dislocation interaction are determined by the atomic structure of the defects and cannot be investigated by continuum treatment.

Osetskiy, Yury N [ORNL; Bacon, David J [University of Liverpool; Rong, Zhouwen [University of Liverpool; Singh, Bachu [Riso National Laboratory, Roskilde, Denmark

2004-01-01

136

The Proteome of Copper, Iron, Zinc, and Manganese Micronutrient Deficiency in Chlamydomonas reinhardtii*  

PubMed Central

Trace metals such as copper, iron, zinc, and manganese play important roles in several biochemical processes, including respiration and photosynthesis. Using a label-free, quantitative proteomics strategy (MSE), we examined the effect of deficiencies in these micronutrients on the soluble proteome of Chlamydomonas reinhardtii. We quantified >103 proteins with abundances within a dynamic range of 3 to 4 orders of magnitude and demonstrated statistically significant changes in ?200 proteins in each metal-deficient growth condition relative to nutrient-replete media. Through analysis of Pearson's coefficient, we also examined the correlation between protein abundance and transcript abundance (as determined via RNA-Seq analysis) and found moderate correlations under all nutritional states. Interestingly, in a subset of transcripts known to significantly change in abundance in metal-replete and metal-deficient conditions, the correlation to protein abundance is much stronger. Examples of new discoveries highlighted in this work include the accumulation of O2 labile, anaerobiosis-related enzymes (Hyd1, Pfr1, and Hcp2) in copper-deficient cells; co-variation of Cgl78/Ycf54 and coprogen oxidase; the loss of various stromal and lumenal photosynthesis-related proteins, including plastocyanin, in iron-limited cells; a large accumulation (from undetectable amounts to over 1,000 zmol/cell) of two COG0523 domain-containing proteins in zinc-deficient cells; and the preservation of photosynthesis proteins in manganese-deficient cells despite known losses in photosynthetic function in this condition. PMID:23065468

Hsieh, Scott I.; Castruita, Madeli; Malasarn, Davin; Urzica, Eugen; Erde, Jonathan; Page, M. Dudley; Yamasaki, Hiroaki; Casero, David; Pellegrini, Matteo; Merchant, Sabeeha S.; Loo, Joseph A.

2013-01-01

137

Rapid Size- Controlled Synthesis of Dextran-Coated, Copper-Doped Iron Oxide Nanoparticles  

NASA Astrophysics Data System (ADS)

Development of dual modality probes enabled for magnetic resonance imaging (MRI) and positron emission tomography (PET) has been on the rise in recent years due to the potential for these probes to facilitate combining the complementary high resolution of MRI and the high sensitivity of PET. The efficient synthesis of multimodal probes that include the radiolabels for PET can be hindered due to prolonged reaction times during radioisotope incorporation, and the resulting decay of the radiolabel. Along with a time-efficient synthesis, one also needs an optimal synthesis that yields products in a desirable size range (between 20-100 nm) to increase blood retention time. In this work, we describe a novel, rapid, microwave-based synthesis of dextran-coated iron oxide nanoparticles doped with copper (DIO/Cu). Traditional methods for synthesizing dextran-coated iron oxide particles require refluxing for 2 hours and result in approximately 50 nm particles. We demonstrate that microwave synthesis can produce 50 nm nanoparticles in 5 minutes of heating. We discuss the various parameters used in the microwave synthesis protocol to vary the size distribution of DIO/Cu, and demonstrate the successful incorporation of copper into these particles with the aim of future use for rapid 64Cu incorporation.

Wong, Ray M.

2011-12-01

138

Synergetic effects of mixed copper-iron oxides oxygen carriers in chemical looping combustion  

SciTech Connect

Chemical looping combustion (CLC) is an emerging technology for clean energy production from fuels. CLC produces sequestration-ready CO{sub 2}-streams without a significant energy penalty. Development of efficient oxygen carriers is essential to successfully operate a CLC system. Copper and iron oxides are promising candidates for CLC. Copper oxide possesses high reactivity but it has issues with particle agglomeration due to its low melting point. Even though iron oxide is an inexpensive oxygen carrier it has a slower reactivity. In this study, mixed metal oxide carriers containing iron and copper oxides were evaluated for coal and methane CLC. The components of CuO and Fe{sub 2}O{sub 3} were optimized to obtain good reactivity while maintaining physical and chemical stability during cyclic reactions for methane-CLC and solid-fuel CLC. Compared with single metal oxygen carriers, the optimized Cu–Fe mixed oxide oxygen carriers demonstrated high reaction rate, better combustion conversion, greater oxygen usage and improved physical stability. Thermodynamic calculations, XRD, TGA, flow reactor studies and TPR experiments suggested that there is a strong interaction between CuO and Fe{sub 2}O{sub 3} contributing to a synergistic effect during CLC reactions. The amount of oxygen release of the mixed oxide carrier in the absence of a fuel was similar to that of the single metal oxides. However, in the presence of fuels, the oxygen consumption and the reaction profiles of the mixed oxide carriers were significantly better than that of the single metal oxides. The nature of the fuel not only influenced the reactivity, but also the final reduction status of the oxygen carriers during chemical looping combustion. Cu oxide of the mixed oxide was fully reduced metallic copper with both coal and methane. Fe oxide of the mixed oxide was fully reduced Fe metal with methane but it was reduced to only FeO with coal. Possible mechanisms of how the presence of CuO enhances the reduction of Fe{sub 2}O{sub 3} are discussed.

Siriwardane, Ranjani; Tian, Hanjing; Simonyi, Thomas; Poston, James

2013-06-01

139

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,...

140

Micronutrient Status in Female University Students: Iron, Zinc, Copper, Selenium, Vitamin B12 and Folate  

PubMed Central

Young women are at an increased risk of micronutrient deficiencies, particularly due to higher micronutrient requirements during childbearing years and multiple food group avoidances. The objective of this study was to investigate biomarkers of particular micronutrients in apparently healthy young women. Female students (n = 308; age range 18–35 year; Body Mass Index 21.5 ± 2.8 kg/m2; mean ± SD) were recruited to participate in a cross-sectional study. Blood samples were obtained from participants in the fasted state and analysed for biomarkers of iron status, vitamin B12, folate, homocysteine, selenium, zinc, and copper. The results show iron deficiency anaemia, unspecified anaemia, and hypoferritinemia in 3%, 7% and 33.9% of participants, respectively. Low vitamin B12 concentrations (<120 pmol/L) were found in 11.3% of participants, while 4.7% showed sub-clinical deficiency based on serum methylmalonic acid concentrations >0.34 ?mol/L. Folate concentrations below the reference range were observed in 1.7% (serum) or 1% (erythrocytes) of participants, and 99.7% of the participant had erythrocyte-folate concentrations >300 nmol/L. Serum zinc concentrations <10.7 ?mol/L were observed in 2% of participants. Serum copper and selenium concentrations were below the reference range in 23% and 11% of participants, respectively. Micronutrient deficiencies including iron and vitamin B12, and apparent excess of folate are present in educated Australian female students of childbearing age, including those studying nutrition. The effects of dietary behaviours and food choices on markers of micronutrient status require further investigation. PMID:25401503

Fayet-Moore, Flavia; Petocz, Peter; Samman, Samir

2014-01-01

141

Haemolysis and Perturbations in the Systemic Iron Metabolism of Suckling, Copper-Deficient Mosaic Mutant Mice – An Animal Model of Menkes Disease  

PubMed Central

The biological interaction between copper and iron is best exemplified by the decreased activity of multicopper ferroxidases under conditions of copper deficiency that limits the availability of iron for erythropoiesis. However, little is known about how copper deficiency affects iron homeostasis through alteration of the activity of other copper-containing proteins, not directly connected with iron metabolism, such as superoxide dismutase 1 (SOD1). This antioxidant enzyme scavenges the superoxide anion, a reactive oxygen species contributing to the toxicity of iron via the Fenton reaction. Here, we analyzed changes in the systemic iron metabolism using an animal model of Menkes disease: copper-deficient mosaic mutant mice with dysfunction of the ATP7A copper transporter. We found that the erythrocytes of these mutants are copper-deficient, display decreased SOD1 activity/expression and have cell membrane abnormalities. In consequence, the mosaic mice show evidence of haemolysis accompanied by haptoglobin-dependent elimination of haemoglobin (Hb) from the circulation, as well as the induction of haem oxygenase 1 (HO1) in the liver and kidney. Moreover, the hepcidin-ferroportin regulatory axis is strongly affected in mosaic mice. These findings indicate that haemolysis is an additional pathogenic factor in a mouse model of Menkes diseases and provides evidence of a new indirect connection between copper deficiency and iron metabolism. PMID:25247420

Lenartowicz, Ma?gorzata; Starzy?ski, Rafa? R.; Krzeptowski, Wojciech; Grzmil, Pawe?; Bednarz, Aleksandra; Ogórek, Mateusz; Pierzcha?a, Olga; Staro?, Robert; Gajowiak, Anna; Lipi?ski, Pawe?

2014-01-01

142

Distribution of trace elements like calcium, copper, iron and zinc in serum samples of colon cancer – A case control study  

Microsoft Academic Search

The pathogenesis of a number of diseases like cardiovascular diseases, diabetes and cancer has been associated with changes in the balance of certain trace elements. In the present study we aimed to investigate the levels of trace elements like calcium, copper, iron and zinc in colon cancer patients in comparison with healthy controls. Serum samples were collected from 256 colon

Nora A. Al Faris; Dilshad Ahmad

2011-01-01

143

Determination of Microamount of Aluminum, Chromium, Copper, Iron, Manganese, Molybdenum and Nickel in Pure Water by Extraction Photometry  

Microsoft Academic Search

Aluminum, iron (III), copper, and molybdenum 8-quinolinol complexes, chromium (III) and manganese 8-hydroxyquinaldine complexes and nickel dimethylglyoxime complex can be quantitatively extracted into chloroform from large volumes of aqueous phases adjusted to an approriate pH for each metal. These metals can be determined by measuring the absorbance of the organic phases containing their complexes at an appropriate wavelength for each

Kenji MOTOJIMA; Nasumi ISHIWATARI

1965-01-01

144

Structure of self-interstitial atom clusters in iron and copper  

SciTech Connect

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.

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

145

Changes in tissue contents of zinc, copper and iron in rats and beagle dogs treated with polaprezinc.  

PubMed

Zinc, copper and iron levels of tissues in rats or beagle dogs were measured after a 13- or 52-week toxicity study of polaprezinc, which contains a zinc element. The zinc content in almost all rat tissues remarkably increased with a conspicuous decrease of copper and various changes of iron at doses of 600 mg/kg/day or more. Zinc and copper levels increased and decreased respectively, at 300 mg/kg/day. At a dose of 150 mg/kg/day, there was a slight increase of zinc in some tissues at 52-weeks, but no copper decrease. The results obtained from beagle dogs differed somewhat from that in rats. Dogs treated with polaprezinc at 50 mg/kg/day or more accumulated zinc in some tissues. A copper decrement was seen only in the liver and heart from the group given 300 mg/kg/day, whereas copper levels in the kidney of all treated groups were higher than that in the control, suggesting that canine polaprezinc toxicity is due to direct zinc toxic effects. PMID:8887886

Yamaguchi, I; Shibata, K; Takei, M; Matsuda, K

1996-08-01

146

Creation of ribbon substrates with a sharp cube texture of copper and copper-nickel alloys additionally alloyed with iron and chromium  

NASA Astrophysics Data System (ADS)

The possibility of obtaining a perfect cube texture in thin ribbon made of binary copper-nickel alloys opens the possibility of using them as substrates in the technology of second-generation HTSC cables. The possibility of production of multicomponent alloys based on a binary Cu-30% Ni alloy additionally alloyed with elements (such as iron or chromium) that strengthen the fcc matrix has been shown. Optimum regimes of annealing have been determined, which make it possible to obtain a perfect biaxial texture with the content of cube grains {001}<100> exceeding 97% in Cu- M and Cu-30Ni- M ( M = Fe or Cr) alloys. In the tapes made of copper alloys with iron or chromium, the precipitation of disperse particles occurs in the process of cooling after recrystallization annealing, which improves the mechanical properties of the substrate. The estimation of the mechanical properties of the textured ribbons of binary and ternary copper alloys demonstrates a yield stress higher than that of the ribbons of pure copper by a factor of 2.5-4.5.

Schastlivtsev, V. M.; Khlebnikova, Yu. V.; Rodionov, D. P.; Gervas'eva, I. V.; Suaridze, T. R.

2014-12-01

147

Photometric and spectrochemical determination of gold in iron pyrites, copper and lead concentrates.  

PubMed

A photometric and a spectrochemical method have been developed for determining gold in iron pyrites, copper and lead concentrates. In both, the sample is dissolved and gold is extracted from 1M hydrochloric add solution with a mixture of ethyl methyl ketone and chloroform (1:1). Gold was determined photometrically with N,N'-tetramethyl-o-tolidine. Conditions have been found for satisfactorily sensitive and reproducible spectral determination of gold. For this purpose the effect of various collectors and buffers on the evaporation curves of gold has been studied, as well as excitation conditions, form of the electrodes, optimum slit-width, and photographic variables. The sensitivity and precision of both methods have been evaluated. PMID:18960389

Jordanov, N; Mareva, S; Krasnobaeva, N; Nedyalkova, N

1968-09-01

148

Correlations between lead, cadmium, copper, zinc, and iron concentrations in frozen tuna fish  

SciTech Connect

The presence of metallic pollutants in marine ecosystems has promoted wide research plans in order to evaluate pollution levels in marine organisms. However, little is known concerning environmental and physiological processes that regulate the concentration of trace metals in marine organisms. Even though the toxicity of lead and cadmium is well established, copper, zinc and iron are considered as essential elements for mammals. Little is known about heavy metals, other than mercury, concentrations in fresh and frozen tuna fish. Fifty samples obtained at the entrance of a canning factory in Santa Cruz de Tenerife (Canary Islands), were analyzed by atomic absorption spectrophotometry. Results were treated by applying the Statistical Package for the Social Sciences compiled and linked in the software of a Digital VAX/VMS 11/780 computer.

Galindo, L.; Hardisson, A.; Montelongo, F.G.

1986-04-01

149

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

PubMed

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

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

2014-12-14

150

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

PubMed Central

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

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

151

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

PubMed

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

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

2014-01-01

152

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...

153

A comparison between the dislocation structure of ball-milled iron and copper as derived from the X-ray diffraction peak profile analyses  

NASA Astrophysics Data System (ADS)

X-ray diffraction line profile analyses were used for determination of the dislocation structure of ball-milled copper and iron samples. Plots of integral breadths of the diffraction line profiles in accordance with the classical Williamson-Hall equation clarified stronger strain anisotropy in iron than copper. By the analyses of the integral breadths in accordance with the modified Williamson-Hall equation, the relative fractions of edge and screw dislocations were determined. Prevailing dislocation structure of copper had edge character while those of iron showed mainly screw character.

Hosseini Nasab, F.; Hossein Nedjad, S.; Karimi, S.

2013-12-01

154

Copper(I)- and copper(0)-promoted homocoupling and homocoupling-hydrodehalogenation reactions of dihalogenoclathrochelate precursors for C-C conjugated iron(II) bis-cage complexes.  

PubMed

Iron(II) dibromo- and diiodoclathrochelates undergo copper(I)-promoted reductive homocoupling in HMPA at 70-80 °C leading to C-C conjugated dibromo- and diiodo-bis-clathrochelates in high yields. Under the same conditions, their dichloroclathrochelate analog does not undergo the same homocoupling reaction, so the target dichloro-bis-cage product was obtained in high yield via dimerization of its heterodihalogenide iodochloromonomacrobicyclic precursor. The use of NMP as a solvent at 120-140 °C gave the mixture of bis-clathrochelates resulting from a tandem homocoupling-hydrodehalogenation reaction: the initial acetonitrile copper(I) solvato-complex at a high temperature underwent re-solvatation and disproportionation leading to Cu(II) ions and nano-copper, which promoted the hydrodehalogenation process even at room temperature. The most probable pathway of this reaction in situ includes hydrodehalogenation of the already formed dihalogeno-bis-clathrochelate via the formation of reduced anion radical intermediates. As a result, chemical transformations of the iron(II) dihalogenoclathrochelates in the presence of an acetonitrile copper(I) solvato-complex were found to depend both on the nature of halogen atoms in their ribbed chelate fragments and on reaction conditions (i.e. solvent and temperature). The C-C conjugated iron(II) dihalogeno-bis-clathrochelates easily undergo nucleophilic substitution with various N,S-nucleophiles giving ribbed-functionalized bis-cage species. These iron(II) complexes were characterized by elemental analysis, MALDI-TOF mass spectrometry, IR, UV-Vis, (1)H and (13)C NMR spectroscopy, and by X-ray diffraction; their electrochemical properties were studied by cyclic voltammetry. The isomeric shift values in (57)Fe Mössbauer spectra of such cage compounds allowed identifying them as low-spin iron(II) complexes, while those of the quadrupole splitting are the evidence for a significant TP distortion of their FeN6-coordination polyhedra. As follows from CV data, the C-C conjugated iron(II) bis-clathrochelates undergo stepwise electrochemical reduction and oxidation giving mixed-valence Fe(II)Fe(I) and Fe(II)Fe(III) bis-cage intermediates. PMID:25056255

Varzatskii, Oleg A; Shul'ga, Sergey V; Belov, Alexander S; Novikov, Valentin V; Dolganov, Alexander V; Vologzhanina, Anna V; Voloshin, Yan Z

2014-12-28

155

Effects of rutin supplementation on antioxidant status and iron, copper, and zinc contents in mouse liver and brain  

Microsoft Academic Search

The effect of rutin on total antioxidant status as well as on trace elements such as iron, copper, and zinc in mouse liver\\u000a and brain were studied. Mice were administrated with 0.75 g\\/kg or 2.25 g\\/kg P. O. of rutin for 30 d consecutively. Following\\u000a the treatment, the activity of total antioxidant status, catalase, Cu,Zn-superoxide dismutase, Mn-superoxide dismutase, zinc,\\u000a copper,

Zhonghong Gao; Huibi Xu; Kaixun Huang

2002-01-01

156

Evaluating the Metal Source(s) of Iron Oxide-Copper-Gold (IOCG) Deposits (Invited)  

NASA Astrophysics Data System (ADS)

Iron oxide - copper - gold deposits (IOCG) are characterized by high modal abundances of magnetite and/or hematite, ubiquitous and variable grades of Cu and Au, and, often, economic grades of other metals including REE, U, Ag, Mo and Zn. The largest deposits contain >1 billion tonnes of iron. There seems to be a general consensus that metals in IOCG deposits were transported by, and precipitated from, aqueous fluids. However, there is a lack of agreement for the source of the metal-bearing aqueous fluid(s) as well as the source of iron and other metals (i.e., magmatic or hydrothermal, or some combination of the two). Published fluid inclusion data indicate that metal-bearing aqueous fluids were trapped over a wide range of temperatures, with homogenization temperatures between 500 and 600 °C for inclusions associated with the precipitation of iron-oxide minerals, and between 300 and 500 °C for inclusions associated with main-stage sulfides (e.g., chalcopyrite, pyrite). The high trapping temperatures for fluid inclusions and the observation that some IOCG deposits appear to be related temporally and spatially to igneous intrusions, characteristics similar to those observed for porphyry-type ore deposits, have led some authors to propose that magmatic-hydrothermal aqueous fluids are responsible for IOCG formation. Others, however, favor a genetic model that invokes large-scale circulation of basinal brines, which are heated by magmatic intrusions and subsequently leach Fe and other metals from the crust. Evidence cited for this model includes the pervasive alkali metasomatism associated with some IOCG deposits, and the depletion of Fe, Cu and Au in some deposit wall rocks. Stable isotope evidence thus far is inconclusive. Published d34S values for IOCG deposits range from -30 to +30, but generally cluster around zero per mil. d18O ranges from ~0 to +10 per mil. Chlorine isotope values for fluids in inclusions liberated from quartz, calcite and apatite are consistent with mantle derived Cl, mixed with basinal brines. All of these data provide important constraints on various aspects of IOCG deposits. None of these data however provide direct evidence for the source of the metals in IOCG deposits. In this contribution, we will evaluate the source of Fe in selected IOCG deposits, as well as the plausibility for other metals to be magmatically sourced. Our approach combines: 1) solubility data for iron in aqueous fluid at temperatures that span the hydrothermal to magmatic regime; 2) new experimental data that constrain the fractionation of iron isotopes among silicate melt, aqueous fluid, magnetite, and sulfide, and at sub-solidus temperatures between aqueous fluid and magnetite; and 3) new iron isotope data for several IOCG deposits of the Coastal Cordillera in northern Chile. The combination of these data allows us to discriminate between the proposed basinal brine and magmatic-hydrothermal models.

Simon, A. C.; Bilenker, L.; Lundstrom, C.; Reich, M.; Barra, F.; Hanchar, J. M.; Westhues, A.

2013-12-01

157

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

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...

Arhelger, Martin Edward

1967-01-01

158

Diffusion bonding of iron aluminide Fe{sub 72}Al{sub 28} using a copper interlayer  

SciTech Connect

An Fe{sub 72}Al{sub 28} alloy was diffusion-bonded using a copper interlayer under vacuum at 1075 deg. C for 1 h, 2 h, 4 h and 6 h durations at 3.2 MPa applied pressure. The bond microstructure was found to be composed of the copper rich interlayer, copper rich precipitates and the base metal. SEM-EDS studies indicated major diffusion of aluminium and iron atoms from Fe{sub 72}Al{sub 28} into the copper interlayer and copper atoms from the copper interlayer into the Fe{sub 72}Al{sub 28} matrix. SEM observations of fractured surfaces of the diffusion-bonded samples showed some plastic deformation and signs of good bonding. Cu{sub 3}Al and B{sub 2}-FeAl-based phases were identified by SEM-EDS and X-ray diffraction studies at the bond and on the fracture surfaces of all samples investigated. Good bonding was achieved with a maximum shear strength of 298 MPa which is 65% of the parent material shear strength for a sample diffusion-bonded for 6 h.

Torun, O. [Afyonkarahisar Kocatepe University, Bolvadin Vocational High School, Afyonkarahisar (Turkey); Celikyuerek, I. [Eskisehir Osmangazi University, Institute of Metallurgy, Eskisehir (Turkey); Guerler, R. [Eskisehir Osmangazi University, Institute of Metallurgy, Eskisehir (Turkey)], E-mail: rgurler@ogu.edu.tr

2008-07-15

159

Limbic system pathologies associated with deficiencies and excesses of the trace elements iron, zinc, copper, and selenium.  

PubMed

Deficiencies of nutrients such as amino acids, vitamins, lipids, and trace elements during gestation and early infanthood have strong deleterious effects on the development of the limbic system; these effects may be irreversible, even when adequate supplementation is provided at later developmental stages. Recent advances in the neurochemistry of biometals are increasingly establishing the roles of the trace elements iron, copper, zinc, and selenium in a variety of cell functions and are providing insight into the repercussions of deficiencies and excesses of these elements on the development of the central nervous system, especially the limbic system. The limbic system comprises diverse areas with high metabolic demands and differential storage of iron, copper, zinc, and selenium. This review summarizes available evidence suggesting the involvement of these trace elements in pathological disorders of the limbic system. PMID:23206282

Torres-Vega, Adriana; Pliego-Rivero, Bernardo F; Otero-Ojeda, Gloria A; Gómez-Oliván, Leobardo M; Vieyra-Reyes, Patricia

2012-12-01

160

Effects of zinc, iron and copper deficiencies on cadmium in tissues of Japanese quail. [Coturnix coturnix japonica  

SciTech Connect

Experiments with young Japanese quail were conducted to determine whether combined moderate deficiencies of zinc, iron and copper would cause greater uptake and tissue retention of cadmium than the single deficiencies. Birds were fed the experimental diets containing 62 ppb cadmium from hatching to 16 days of age. On day 9 each bird received a dose of /sup 109/CdCl/sub 2/ in its diet. On day 10, the duodenal and jejunal-ileal tissues contained large amounts of cadmium, and there were many significant effects of treatment on cadmium-109 retention in the livers and kidneys. At day 16, zinc deficiency caused increased cadmium in the liver, whereas iron and copper deficiencies each caused increased cadmium in the kidneys. Combined deficiencies had little or no greater effect than single deficiencies and in some cases the combined effect was less than that of a single deficiency. 13 references, 11 tables.

Fox, M.R.S.; Tao, S.H.; Stone, C.L.; Fry, B.E. Jr.

1984-03-01

161

Tribological behaviour and statistical experimental design of sintered iron-copper based composites  

NASA Astrophysics Data System (ADS)

The sintered iron-copper based composites for automotive brake pads have a complex composite composition and should have good physical, mechanical and tribological characteristics. In this paper, we obtained frictional composites by Powder Metallurgy (P/M) technique and we have characterized them by microstructural and tribological point of view. The morphology of raw powders was determined by SEM and the surfaces of obtained sintered friction materials were analyzed by ESEM, EDS elemental and compo-images analyses. One lot of samples were tested on a "pin-on-disc" type wear machine under dry sliding conditions, at applied load between 3.5 and 11.5 × 10-1 MPa and 12.5 and 16.9 m/s relative speed in braking point at constant temperature. The other lot of samples were tested on an inertial test stand according to a methodology simulating the real conditions of dry friction, at a contact pressure of 2.5-3 MPa, at 300-1200 rpm. The most important characteristics required for sintered friction materials are high and stable friction coefficient during breaking and also, for high durability in service, must have: low wear, high corrosion resistance, high thermal conductivity, mechanical resistance and thermal stability at elevated temperature. Because of the tribological characteristics importance (wear rate and friction coefficient) of sintered iron-copper based composites, we predicted the tribological behaviour through statistical analysis. For the first lot of samples, the response variables Yi (represented by the wear rate and friction coefficient) have been correlated with x1 and x2 (the code value of applied load and relative speed in braking points, respectively) using a linear factorial design approach. We obtained brake friction materials with improved wear resistance characteristics and high and stable friction coefficients. It has been shown, through experimental data and obtained linear regression equations, that the sintered composites wear rate increases with increasing applied load and relative speed, but in the same conditions, the frictional coefficients slowly decrease.

Popescu, Ileana Nicoleta; Ghi??, Constantin; Bratu, Vasile; Palacios Navarro, Guillermo

2013-11-01

162

Investigations into the uptake of copper, iron and selenium by a highly sulphated bacterial exopolysaccharide isolated from microbial mats  

Microsoft Academic Search

A bacterium isolated from microbial mats located on a polynesian atoll produced a high molecular weight (3,000 kDa) and highly\\u000a sulphated exopolysaccharide. Previous studies showed that the chemical structure of this EPS consisted of neutral sugars,\\u000a uronic acids, and high proportions of acetate and sulphate groups. The copper- and iron-binding ability of the purified pre-treated\\u000a native EPS was investigated. Results

Xavier Moppert; Tinaïg Le Costaouec; Gérard Raguenes; Anthony Courtois; Christelle Simon-Colin; Philippe Crassous; Bernard Costa; Jean Guezennec

2009-01-01

163

Copper mobility in the Eastern Creek Volcanics, Mount Isa, Australia: evidence from laser ablation ICP-MS of iron-titanium oxides  

Microsoft Academic Search

The Palaeoproterozoic Eastern Creek Volcanics are a series of copper-rich tholeiitic basalts which occur adjacent to the giant sediment-hosted Mount Isa copper deposit in Queensland, Australia. The volcanic rocks are often cited as the source of metals for the deposit. New laser ablation ICP-MS analyses of iron–titanium oxides from the basalts provide evidence for the local mobilisation of copper during

Melissa J. Gregory

2006-01-01

164

The effect of occupational lead exposure on blood levels of zinc, iron, copper, selenium and related proteins.  

PubMed

The study objective was to evaluate the effect of occupational lead exposure on blood concentrations of zinc, iron, copper, selenium and proteins related to them, such as transferrin, caeruloplasmin and haptoglobin. The examined group consisted of 192 healthy male employees of zinc-lead works. By the degree of lead exposure, the exposed group was subdivided into three subgroups. The control group was composed of 73 healthy male administrative workers. The markers of lead exposure (blood levels of lead and zinc protoporphyrin) were significantly elevated in the exposed group compared with the control group. Additionally, concentrations of copper and caeruloplasmin were raised. The significant increase in haptoglobin level was observed only in the low exposure group. Selenium levels were significantly decreased, whereas iron, zinc and transferrin levels were unchanged in the exposed group compared with the control group. There were positive correlations between the lead toxicity parameters and the copper and caeruloplasmin levels. In conclusion, the effect of occupational exposure to lead on the metabolism of trace metals appears to be limited. However, significant associations between lead exposure and levels of copper and selenium were shown. Changed levels of positive acute-phase proteins, such as caeruloplasmin and haptoglobin, were also observed. PMID:22923205

Kasperczyk, Aleksandra; Prokopowicz, Adam; Dobrakowski, Micha?; Pawlas, Natalia; Kasperczyk, S?awomir

2012-12-01

165

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

PubMed Central

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

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

2013-01-01

166

Influence of organic matter on the uptake of cadmium, zinc, copper and iron by sorghum plants.  

PubMed

This article describes an experiment, carried out under controlled environment conditions, to investigate the effects of a fulvic acid fraction of soil organic matter on growth, cadmium (Cd) uptake and redistribution by sorghum. In addition the uptake of copper (Cu), zinc (Zn) and iron (Fe) was also determined. Sorghum was grown in nutrient solutions with 0, 0.1, 1 and 10 mg Cd dm(-3), in the absence and presence of organic matter (32 mg C dm(-3)), for various periods up to 20 days. A decrease in sorghum biomass due to Cd toxicity was observed at 10 mg Cd dm(-3), but for concentrations of 0.1 and 1 mg Cd dm(-3) the biomass was increased compared with control, without visual toxicity symptoms. The presence of organic matter (OM) further increased biomass production. Cadmium was mainly retained in sorghum roots, as usually found in tolerant plants, but Cd accumulation in sorghum was greater than in other Gramineae, or even more tolerant plants such as lettuce. The presence of OM decreased the bioavailability of Cd that was partially retained in solution by the OM ligands. However, OM promoted the translocation of Cd to shoots, an effect that may pose a risk to public health because plant-animal transfer of Cd could be enhanced. The presence of OM decreased the uptake of Cu, Zn and Fe. The presence (vs. absence) of 0.1 mg Cd dm(-3) enhanced the uptake of Fe, both in the absence and presence of OM. PMID:15142779

Pinto, A P; Mota, A M; de Varennes, A; Pinto, F C

2004-06-29

167

Bleomycin-detectable iron and phenanthroline-detectable copper in the cerebrospinal fluid of patients with neuronal ceroid-lipofuscinoses.  

PubMed

The neuronal ceroid-lipofuscinoses (NCLs) are a group of recessively inherited neurodegenerative lysosomal storage diseases, the pathogenesis of which is unknown. In the present study, we have measured iron and cooper in cerebrospinal fluids (CSF) using methods that detect these metals in a "loosely bound" form, complexable to the chelators bleomycin and 1,10-phenanthroline. We studied 25 children with NCL, 21 children with encephalopathy of some other type, and 5 control children without neurological complications. The CSF concentrations of loosely bound iron at neutral pH values and of loosely bound copper did not correlate with the clinical diagnosis of the patients, nor did they parallel degenerative symptoms in NCL, such as mental impairment, visual loss, motor handicap, and epilepsy. However, the concentrations of loosely bound iron and copper increased significantly with the age of the patient; this is a novel finding and may represent increasing tissue destruction with age. Our present findings do not support a major role for primary iron toxicity in the development of neuronal degeneration. To investigate any secondary pathological role for malplaced transition metals, further research is required. PMID:2464355

Heiskala, H; Gutteridge, J M; Westermarck, T; Alanen, T; Santavuori, P

1988-01-01

168

Ion paired chromatography of iron (II,III), nickel (II) and copper (II) as their 4,7Diphenyl1,10-phenanthroline chelates  

Microsoft Academic Search

A reversed phase ion-paired chromatographic method that can be used to determine trace amounts of iron (II,III), nickel (II) and copper (II) was developed and applied to the determination of iron (II) and iron (III) levels in natural water. The separation of these metal ions as their 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline) chelates on an Inertsil ODS column was investigated by using acetonitrile-water

N Mudasir; Naoki Yoshioka; Hidenari Inoue

1997-01-01

169

Copper  

MedlinePLUS

... at whether a copper-lowering drug, tetrathiomolybdate (or TM), could help patients with advanced kidney cancer. Some ... more people with advanced cancer. More study of TM and a related drug (ATN-224) is taking ...

170

M-Type Barium Hexagonal Ferrite Films Mingzhong Wu  

E-print Network

-type barium hexagonal ferrite BaFe12O19 (BaM) films as a replacement for those magnetic garnets. BaM films can2 M-Type Barium Hexagonal Ferrite Films Mingzhong Wu Department of Physics, Colorado State University, Fort Collins, USA 1. Introduction Magnetic garnet materials such as yttrium iron garnet (YIG

171

Seasonal and locational effects on serum, milk, liver and kidney chromium, manganese, copper, zinc, and iron concentrations of dairy cows.  

PubMed

Chromium (Cr), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) concentrations were quantified in serum (n = 112), milk (n = 112), liver (n = 70), and kidney samples (n = 67) of dairy cows from an iron-steel processing region (Payas-Iskenderun) and from an area free of industrial pollution (Antakya) in Hatay, located in Southern Turkey. Samples were collected in the summer and winter and element determinations were carried out by inductively coupled plasma-atomic emission spectrometry. The mean concentrations of selected elements in serum were found to be similar in both regions. Milk samples collected from the nonindustrial region in the summer had higher Cr, Mn, and Zn concentrations than the polluted region. The liver Cu and kidney Mn levels of samples taken from the industrial region in winter were higher than samples of the unpolluted region. Copper and Fe concentrations in milk, Cr, Mn, Zn, and Fe levels in the liver, and Cr, Cu, Zn, and Fe levels in kidney samples were not found to be different among the regions in both seasons. Copper concentrations were below the critical level in the 25% of serum and 32% of liver samples analyzed in this study. Fifteen percent of serum samples and most of the liver samples had lower amounts of Zn than other reported studies. Although slight differences were observed between the industrial and nonindustrial regions, industrial activities and seasonal changes had no significant effect on selected element concentrations on cows and their milk. PMID:15051900

Erdogan, Suat; Celik, Sefa; Erdogan, Zeynep

2004-04-01

172

Influence of iron and copper oxides on polychlorinated diphenyl ether formation in heterogeneous reactions.  

PubMed

Polychlorinated diphenyl ether (PCDE) has attracted great attention recently as an important type of environmental pollutant. The influence of iron and copper oxides on formation of PCDEs was investigated using laboratory-scale flow reactors under air and under nitrogen at 350 °C, a temperature corresponding to the post-combustion zone of a municipal solid waste incinerator. The results show that the 2,2',3,4,4',5,5',6-otachlorodiphenyl ether (OCDE) formed from the condensation of pentachlorophenol (PCP) and 1,2,4,5-tetrachlorobenzene (Cl4Bz) is the predominant congener formed on the SiO2/Fe2O3 surface with and without oxygen. This indicated that HCl elimination between PCP and 1,2,4,5-Cl4Bz molecules formed 2,2',3,4,4',5,5',6-OCDE in the presence of Fe2O3. On the other hand, decachlorodiphenyl ether, nonachlorodiphenyl ether, and OCDE were the dominant products on the SiO2/CuO surface without oxygen, although the 2,2',3,4,4',5,5',6-OCDE was the dominant product on the SiO2/CuO surface with oxygen. Therefore, the presence of Fe2O3 and CuO influences the formation and homologue distribution of PCDEs, which shifted towards the lower chlorinated species. Fe2O3 can promote both the condensation and dechlorination reaction without oxygen. On the contrary, with oxygen, Fe2O3 suppresses the condensation of chlorobenzene and chlorophenol to form PCDEs and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). CuO can increase the formation of lower chlorinated PCDEs and PCDDs without oxygen. In conclusion, the different fly ash components have a major influence on PCDE emissions. PMID:23440438

Liu, Wenxia; Shen, Lianfeng; Zhang, Fawen; Liu, Wenbin; Zheng, Minghui; Yang, Xitian

2013-08-01

173

Effect of the metals iron, copper and silver on fluorobenzene biodegradation by Labrys portucalensis.  

PubMed

Organic and metallic pollutants are ubiquitous in the environment. Many metals are reported to be toxic to microorganisms and to inhibit biodegradation. The effect of the metals iron, copper and silver on the metabolism of Labrys portucalensis F11 and on fluorobenzene (FB) biodegradation was examined. The results indicate that the addition of 1 mM of Fe(2+) to the culture medium has a positive effect on bacterial growth and has no impact in the biodegradation of 1 and 2 mM of FB. The presence of 1 mM of Cu(2+) was found to strongly inhibit the growth of F11 cultures and to reduce the biodegradation of 1 and 2 mM of FB to ca. 50 %, with 80 % of stoichiometrically expected fluoride released. In the experiments with resting cells, the FB degraded (from 2 mM supplied) was reduced ca. 20 % whereas the fluoride released was reduced to 45 % of that stoichiometrically expected. Ag(+) was the most potent inhibitor of FB degradation. In experiments with growing cells, the addition of 1 mM of Ag(+) to the culture medium containing 1 and 2 mM of FB resulted in no fluoride release, whereas FB degradation was only one third of that observed in control cultures. In the experiments with resting cells, the addition of Ag(+) resulted in 25 % reduction in substrate degradation and fluoride release was only 20 % of that stoichiometrically expected. The accumulation of catechol and 4-fluorocatechol in cultures supplemented with Cu(2+) or Ag(+) suggest inhibition of the key enzyme of FB metabolism-catechol 1,2-dioxygenase. PMID:22842857

Moreira, Irina S; Amorim, Catarina L; Carvalho, Maria F; Ferreira, António C; Afonso, Carlos M; Castro, Paula M L

2013-04-01

174

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, ...

175

The membrane-associated form of methane mono-oxygenase from Methylococcus capsulatus (Bath) is a copper/iron protein.  

PubMed Central

A protocol has been developed which permits the purification of a membrane-associated methane-oxidizing complex from Methylococcus capsulatus (Bath). This complex has approximately 5 fold higher specific activity than any purified particulate methane mono-oxygenase (pMMO) previously reported from M. capsulatus (Bath). This efficiently functioning methane-oxidizing complex consists of the pMMO hydroxylase (pMMOH) and an unidentified component we have assigned as a potential pMMO reductase (pMMOR). The complex was isolated by solubilizing intracytoplasmic membrane preparations containing the high yields of active membrane-bound pMMO (pMMO(m)), using the non-ionic detergent dodecyl-beta-D-maltoside, to yield solubilized enzyme (pMMO(s)). Further purification gave rise to an active complex (pMMO(c)) that could be resolved (at low levels) by ion-exchange chromatography into two components, the pMMOH (47, 27 and 24 kDa subunits) and the pMMOR (63 and 8 kDa subunits). The purified complex contains two copper atoms and one non-haem iron atom/mol of enzyme. EPR spectra of preparations grown with (63)Cu indicated that the copper ion interacted with three or four nitrogenic ligands. These EPR data, in conjunction with other experimental results, including the oxidation by ferricyanide, EDTA treatment to remove copper and re-addition of copper to the depleted protein, verified the essential role of copper in enzyme catalysis and indicated the implausibility of copper existing as a trinuclear cluster. The EPR measurements also demonstrated the presence of a tightly bound mononuclear Fe(3+) ion in an octahedral environment that may well be exchange-coupled to another paramagnetic species. PMID:12379148

Basu, Piku; Katterle, Bettina; Andersson, K Kristoffer; Dalton, Howard

2003-01-01

176

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

PubMed Central

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

Weisenberg, Emil; Halbreich, Avraham; Mager, Jacob

1980-01-01

177

Magnetic properties of La–Co substituted barium ferrite thin films with large magnetic anisotropy  

Microsoft Academic Search

Barium ferrite thin films with lanthanum ions and cobalt ions substituted for barium ions and iron ions have been prepared by conventional diode sputtering method. The hexagonal magnetoplumbite structure was formed by an annealing at 800°C or above. La–Co-substituted barium ferrite thin films had large magnetic anisotropy compared with non-substituted barium ferrite thin films. Moreover, an attempt was also made

K. Kakizaki; H. Taguchi; N. Hiratsuka

2004-01-01

178

Erythrocytic antioxidant defense, lipid peroxides level and blood iron, zinc and copper concentrations in dogs naturally infected with Babesia gibsoni.  

PubMed

Babesiosis is a common tick borne disease of dogs in tropical and subtropical regions of the world caused by different species of Babesia. The present study aimed to examine erythrocyte lipid peroxide and erythrocytic antioxidant levels in dogs with clinical babesiosis, caused by Babesia gibsoni, and impact of the disease on blood iron, zinc and copper levels. The study was conducted on 10 naturally occurring cases of canine babesiosis with the history of tick infestation, erratic pyrexia, and prolonged illness. Microscopic examination of Giemsa stained peripheral blood smears confirmed B. gibsoni infection in the erythrocytes. Six apparently healthy dogs of different age, sex and breeds, brought for either health checkup or vaccination were used for comparison. Levels of erythrocytic antioxidant enzymes were significantly (P<0.01) higher in sick dogs than those of cytologically negative dogs (catalase: 0.192+/-0.024 units/mg Hb vs 0.074+/-0.004 units/mg Hb; superoxide dismutase: 0.014+/-0.0009 units/mg Hb vs 0.006+/-0.0008 units/mg Hb and lipid peroxide: 6.01+/-0.30 nmol MDA/mg Hb vs 1.89+/-0.10 nmol MDA/mg Hb). The levels of blood micronutrients were significantly low in these dogs (iron: 89.87+/-8.12 microg/g vs 126.44+/-14.65 microg/g; zinc: 3.67+/-1.85 microg/g vs 5.62+/-1.83 microg/g and copper: 0.55+/-0.63 microg/g vs 0.65+/-0.04 microg/g). The study demonstrated oxidative damage in dogs naturally infected with B. gibsoni. Low level of blood iron, zinc and copper seems to have an additional role in the genesis of anaemia and oxidative stress. PMID:18378268

Chaudhuri, S; Varshney, J P; Patra, R C

2008-08-01

179

In vitro toxicological assessment of iron oxide, aluminium oxide and copper nanoparticles in prokaryotic and eukaryotic cell types.  

PubMed

ABSTRACT Metallic nanoparticles (NPs) have a variety of applications in different industries including pharmaceutical industry where these NPs are used mainly for image analysis and drug delivery. The increasing interest in nanotechnology is largely associated with undefined risks to the human health and to the environment. Therefore, in the present study cytotoxic and genotoxic effects of iron oxide, aluminium oxide and copper nanoparticles were evaluated using most commonly used assays i.e. Ames assay, in vitro cytotoxicity assay, micronucleus assay and comet assay. Cytotoxicity to bacterial cells was assessed in terms of colony forming units by using Escherichia coli (gram negative) and Bacillus subtilis (gram positive). Ames assay was carried out using two bacterial strains of Salmonella typhimurium TA98 and TA100. Genotoxicity of these NPs was evaluated following exposure to monkey kidney cell line, CHS-20. No cytotoxic and genotoxic effects were observed for iron oxide, and aluminium oxide NPs. Copper NPs were found mutagenic in TA98 and in TA100 and also found cytotoxic in dose dependent manner. Copper NPs induced significant (p?Copper NPs also induced DNA strand breaks at 10?µg/mL and oxidative DNA damage at 5 and 10?µg/mL. We consider these findings very useful in evaluating the genotoxic potential of NPs especially because of their increasing applications in human health and environment with limited knowledge of their toxicity and genotoxicity. PMID:24896217

Sadiq, Rakhshinda; Khan, Qaiser Mahmood; Mobeen, Ameena; Hashmat, Amer Jamal

2014-06-01

180

Iron assisted growth of copper-tipped multi-walled carbon nanotubes  

Microsoft Academic Search

Carbon nanotubes incorporating copper are highly sought after for nanoelectronic applications. Indeed, several recent studies have demonstrated the production of copper-tipped nanotubes using the chemical vapor deposition method. Here we present the growth and detailed characterization of such copper-tipped nanotubes. The nanotubes grown were of a 'bamboo-like' structure, consisting of stacked cups of graphene, and were produced by chemical vapor

Z. R. Abrams; D. Szwarcman; Y. Lereah; G. Markovich; Y. Hanein

2007-01-01

181

Microdistribution of copper-carbonate and iron oxide nanoparticles in treated wood  

Microsoft Academic Search

Aqueous dispersions of copper-carbonate nanoparticles and microparticles have just begun to be exploited commercially for\\u000a the preservative treatment of wood. The success of the new systems will depend, in part, on the uniform distribution of the\\u000a preservative in wood and the ability of copper to penetrate cell walls. We examined the distribution of copper in wood treated\\u000a with a nano-Cu

Hiroshi Matsunaga; Makoto Kiguchi; Philip D. Evans

2009-01-01

182

COPPER ADSORPTION IN OXIDIC SOILS AFTER REMOVAL OF ORGANIC MATTER AND IRON OXIDES  

Microsoft Academic Search

Copper (Cu), despite being an essential micronutrient, may be toxic whenever it occurs in the soil solution at high concentrations. Chemical reactions that control copper availability in the soil–plant system are complex. Copper can be found in both organic and inorganic soil fractions. This work studied Cu adsorption into surface (0–0.2 m) and subsurface (in the B2 horizon) samples from three

Maria Lucia Azevedo Silveira; Luís Reynaldo Ferracciú Alleoni; Otávio Antônio Camargo; José Carlos Casagrande

2002-01-01

183

Zinc, iron, manganese, and magnesium accumulation in crayfish populations near copper-nickel smelters at Sudbury, Ontario, Canada  

SciTech Connect

The Sudbury basin has been subjected to extreme ecological disturbances from logging, mining and smelting activities. Elevated concentrations of copper, cadmium, and nickel have been reported in crayfish populations close to the Sudbury smelting works. The present study compares concentrations of zinc (Zn), iron (Fe), manganese (Mn) and magnesium (Mg) in freshwater crayfish at selected distances of the habitat from the emission source. These metals were selected since they are known to be emitted in moderately high quantities into the Sudbury environment as byproduct of the smelting process. Various tissue concentrations in crayfish were also examined to determined specific tissue sites for these accumulations.

Bagatto, G.; Alikhan, M.A.

1987-06-01

184

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

E-print Network

(dopamine b-hydroxylase, pepti- dylglycine a-hydroxylating monooxygenase, tyrosinase, and particulate proteins include hemocya- nin, tyrosinase, and catechol oxidase.[5, 7] The binuclear copper centers

Chen, Peng

185

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)

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.

Ferrante, J.

1973-01-01

186

Barium enema (image)  

MedlinePLUS

A barium enema is performed to examine the walls of the colon. During the procedure, a well lubricated enema tube is inserted gently into the rectum. The barium, a radiopaque (shows up on X-ray) contrast ...

187

Characterization of Precious Metal Resources in Copper Slag and Their Implications in Beneficiation  

NASA Astrophysics Data System (ADS)

Studies have been carried out on precious metal association, on a typical Indian copper slag sample using SEM-EDS. The studies revealed the presence of platinum as well as gold, reported here for the first time, in the copper metal as well as different types of metallic sulphides phases of the copper slag. These phases are either entrapped in the silicate minerals or are present as free liberated grains within the slag sample. The platinum content varies in the range of 1.24-1.95 wt% whereas gold values range from 2.41 to 5.90 wt% in some phases. The phases of copper slag, which contain gold and platinum are present in very less quantity with respect to volume percentage. The major phases, in the copper slag are fayalite and magnetite while spinel, ulvospinel, metallic iron, calcium oxide and barium sulphide are minor phases and all these are devoid of gold or platinum.

Rao, D. S.; Angadi, S.; Reddy, P. S. R.

2015-01-01

188

Characterization of Precious Metal Resources in Copper Slag and Their Implications in Beneficiation  

NASA Astrophysics Data System (ADS)

Studies have been carried out on precious metal association, on a typical Indian copper slag sample using SEM-EDS. The studies revealed the presence of platinum as well as gold, reported here for the first time, in the copper metal as well as different types of metallic sulphides phases of the copper slag. These phases are either entrapped in the silicate minerals or are present as free liberated grains within the slag sample. The platinum content varies in the range of 1.24-1.95 wt% whereas gold values range from 2.41 to 5.90 wt% in some phases. The phases of copper slag, which contain gold and platinum are present in very less quantity with respect to volume percentage. The major phases, in the copper slag are fayalite and magnetite while spinel, ulvospinel, metallic iron, calcium oxide and barium sulphide are minor phases and all these are devoid of gold or platinum.

Rao, D. S.; Angadi, S.; Reddy, P. S. R.

2015-04-01

189

Re–Os and Pb–Pb geochronology of the Archean Salobo iron oxide copper–gold deposit, Carajás mineral province, northern Brazil  

Microsoft Academic Search

Rhenium–osmium ages were determined for two molybdenite samples and a Pb–Pb age was derived from bornite–chalcopyrite–magnetite at the Salobo iron oxide copper–gold deposit to determine the timing of mineralization and its relation to the nearby Old Salobo Granite. Rhenium–osmium dating of molybdenite spatially associated with copper sulfide minerals yields ages with weighted means of 2576±8 and 2562±8 Ma. Removing the error

Karin Requia; Holly Stein; Lluís. Fontboté; Massimo Chiaradia

2003-01-01

190

Bosonics in the copper and iron based high transition temperature superconductors  

NASA Astrophysics Data System (ADS)

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.

Niestemski, Francis Charles

191

New Measurements of the Densities of Copper, Nickel, and Iron Sulfide Liquids  

NASA Astrophysics Data System (ADS)

Density measurements of sulfide liquids in the Fe-Ni-Cu-S-O system were performed from 1150°C-1250°C under controlled oxygen and sulfur fugacities. Measurements were made using the modified single bob (MSB) Archimedean method using zirconia ceramic bobs and crucibles. A 0.005mm resolution micrometer was attached to an elevator, which raised the crucible and melt relative to the free-hanging, stationary bob. A 0.001 g resolution analytical balance connected to a laptop computer continuously recorded the buoyancy as a function of crucible elevation. Densities were calculated by converting elevation to immersed volume and regressing the slope of buoyancy versus volume immersed. log(fO2) in the experiments ranged from -7.8 to -12.6 and log(fS2) ranged from -0.9 to -3.3. 38 successful sulfide liquid density measurements were performed, with values ranging from 3.8 g/cc to 6.6 g/cc. Regression of the resulting data suggests that a simple linear volume mixing model is adequate to represent the compositional dependence of density in copper- and nickel-sulfide liquids. A moderate positive excess mixing volume appears to be justified in iron-sulfide liquids. This result, along with high derived partial molar volumes for oxygen and sulfur components, are qualitatively consistent with the suggestion that increasing pressure will partition oxygen and sulfur out of the sulfide liquid during planetary accretion. The MSB density measurement also provides information on the relative magnitude of gas-zirconia and sulfide-zirconia surface energies. Assuming most of the observed variation results from sulfide chemistry it appears that oxidizing conditions significantly decrease sulfide-zirconia surface energies (increase wetting). If we can extrapolate this result to silicate minerals, this would suggest that oxidizing conditions will decrease wetting angle and thus increase the potential for sulfide segregation during planetary formation. We hope to test this hypothesis soon. Our experience suggests that trivial modifications to the apparatus used in this study may provide an effective and reliable method for measuring liquid-solid surface energies in both sulfide and silicate systems. Such data would prove useful in both melt percolation and bubble nucleation and growth calculations.

Mioduszewski, L.; Kress, V. C.

2005-12-01

192

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 ...

193

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

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

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

2015-03-01

194

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

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

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

2015-01-01

195

Ferrous iron oxidation and leaching of copper ore with halotolerant bacteria in ore columns  

Microsoft Academic Search

Growth on ferrous iron of a new isolate of the acidophile Thiobacillus prosperus occurred with a substrate oxidation rate similar to that of Acidithiobacillus ferrooxidans. As well as similar capacities for iron oxidation, these species were shown to possess similar, but not identical, clusters of genes (the rus operon) that encode proteins likely to be involved in transfer of electrons

Carol S. Davis-Belmar; James Le C. Nicolle; Paul R. Norris

2008-01-01

196

Improved properties of barium strontium titanate thin films grown on copper foils by pulsed laser deposition using a self-buffered layer.  

SciTech Connect

Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} (BST) films were deposited by pulsed laser deposition on copper foils with low-temperature self-buffered layers. The deposition conditions included a low oxygen partial pressure and a temperature of 700 C to crystallize the films without the formation of secondary phases and substrate oxidation. The results from x-ray diffraction and scanning electron microscopy indicated that the microstructure of the BST films strongly depended on the growth temperature. The use of the self-buffered layer improved the dielectric properties of the deposited BST films. The leakage current density of the BST films on the copper foil was 4.4 x 10{sup -9} A cm{sup -2} and 3.3 x 10{sup -6} A cm{sup -2} with and without the self-buffered layer, respectively. The ferroelectric hysteresis loop for the BST thin film with buffer layer was slim, in contrast to the distorted loop observed for the film without the buffer layer. The permittivity (7 0 0) and dielectric loss tangent (0.013) of the BST film on the copper foil with self-buffered layer at room temperature were comparable to those of the film on metal and single-crystal substrates.

Liu, S.; Ma, B.; Narayanan, M.; Balachandran, U. (Energy Systems)

2012-01-01

197

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

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

198

The effect of hexadecyl pyridinium bromide and hexadecyl trimethyl ammonium bromide on the behaviour of iron and copper in acidic solutions  

Microsoft Academic Search

The effect of hexadecyl pyridinium bromide (HPB) and hexadecyl trimethyl ammonium bromide (HTAB) on the corrosion behaviour of iron and copper in hydrochloric and sulphuric acid solutions has been investigated by potentiodynamic polarization and Tafel extrapolation methods. The polarization curves indicate that the two compounds behave as mixed inhibitors, but the cathode is more inhibited. HPB is more effective than

S. A. Abd El-Maksoud

2004-01-01

199

[Study on synthesis and molecular spectra of the N-(2-hydroxy) naphthylmethyleneamino iron(III), cobalt(II) and copper(II) complexes].  

PubMed

The title complexes were synthesized via reaction of iron nitrate, cobalt acetate and copper acetate with the didentate O,N-donor Schiff bases in methanol solution. The electronic and infrared spectra of these complexes were measured and the major IR bands were assigned. PMID:15810239

Kuang, D; Zhang, F

1997-12-01

200

Circulating Immune Complexes and trace elements (Copper, Iron and Selenium) as markers in oral precancer and cancer : a randomised, controlled clinical trial  

Microsoft Academic Search

AIM: To evaluate the levels of circulating immune complexes, trace elements (copper, iron and selenium) in serum of patients with oral submucous fibrosis (OSMF), oral leukoplakia (L), and oral squamous cell carcinoma (SCC), analyze the alteration and identify the best predictors amongst these parameters for disease occurrence and progression. METHODS: Circulating immune complexes (CIC) were estimated using 37.5% Polyethylene Glycol

Sunali S Khanna; Freny R Karjodkar

2006-01-01

201

Preconcentration and determination of iron and copper in spice samples by cloud point extraction and flow injection flame atomic absorption spectrometry.  

PubMed

A flow injection (FI) cloud point extraction (CPE) method for the determination of iron and copper by flame atomic absorption spectrometer (FAAS) has been improved. The analytes were complexed with 3-amino-7-dimethylamino-2-methylphenazine (Neutral Red, NR) and octylphenoxypolyethoxyethanol (Triton X-114)wasadded as a surfactant. The micellar solutionwasheated above 50 degrees C and loaded through a column packed with cotton for phase separation. Then the surfactant-rich phase was eluted using 0.05 mol L(-1) H2SO4 and the analytes were determined by FAAS. Chemical and flow variables influencing the instrumental and extraction conditions were optimized. Under optimized conditions for 25 mL of preconcentrated solution, the enrichment factors were 98 and 69, the limits of detection (3s) were 0.7 and 0.3 ng mL(-1), the limits of quantification (10s) were 2.2 and 1.0 ng mL(-1) for iron and copper, respectively. The relative standard deviation (RSD) for ten replicate measurements of 10 ng mL(-1) iron and copper were 2.1% and 1.8%, respectively. The proposed method was successfully applied to determination of iron and copper in spice samples. PMID:20627408

Sahin, Ci?dem Arpa; Tokgöz, Ilknur; Bekta?, Sema

2010-09-15

202

Photochemical aerobic detoxification of aqueous phenol and chlorophenol solutions promoted by iron salts and iron, vanadium, and copper oxides  

SciTech Connect

Phenol, 2,4,5-trichlorophenol, and pentachlorophenol in air in the presence of soluble iron salts or insoluble V{sub 2}O{sub 5}, Fe{sub 2}O{sub 3}, and CuO decompose in aqueous solution when irradiated by a luminescent lamp. The degree and the rate of decomposition are strongly influenced by the nature of the substrate and metal-containing promoter. As a result of decomposition, toxicity of solutions containing 2,4,5-trichlorophenol with respect to two types of living organisms - Protozoa (Tetrahymena pyriformis) and bacteria (Beneckea harveyi) - decreases significantly.

Nizova, G.V.; Bochkova, M.M.; Kozlova, N.B.; Shul`pin, G.B. [N.N. Semenov Institute of Chemical Physics, Moscow (Russian Federation)

1995-09-10

203

Barium titanium glycolate: A new barium titanate powder precursor  

SciTech Connect

This paper describes the synthesis and structure of a barium titanium glycolate complex and the calcination into barium titanate preceramic powders that sinter into polycrystalline, tetragonal barium titanate having good dielectric properties.

Day, V.W.; Klemperer, W.G.; Payne, D.A. [Univ. of Nebraska, Lincoln, NE (United States)] [and others] [Univ. of Nebraska, Lincoln, NE (United States); and others

1996-02-01

204

Virus inactivation by copper or iron ions alone and in the presence of peroxide.  

PubMed

Cupric and ferric ions were able to inactivate five enveloped or nonenveloped, single- or double-stranded DNA or RNA viruses. The virucidal effect of these metals was enhanced by the addition of peroxide, particularly for copper(II). Under the conditions of our test, mixtures of copper(II) ions and peroxide were more efficient than glutaraldehyde in inactivating phi X174, T7, phi 6, Junin, and herpes simplex viruses. The substances described here should be able to inactivate most, if not all, viruses that have been found contaminating medical devices. PMID:8285724

Sagripanti, J L; Routson, L B; Lytle, C D

1993-12-01

205

Insight into Bio-metal Interface Formation in vacuo: Interplay of S-layer Protein with Copper and Iron  

PubMed Central

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

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

206

Insight into Bio-metal Interface Formation in vacuo: Interplay of S-layer Protein with Copper and Iron  

NASA Astrophysics Data System (ADS)

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.

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.

2015-03-01

207

Barium ferrite permanent magnets  

Microsoft Academic Search

1.We have selected and introduced the following optimum conditions for the preparation of isotropic barium ferrite magnets:a)Barium oxide content 15 ± 1%; b) kaolin content 1%; c) roasting of mixture of ferric oxide and barium salt at temperatures of 900–950‡ with five hours holding time; d) pressure during pressing 1.5–2 t\\/cm2; e) sintering of magnets at a temperature of 1160–1260‡

I. Yu. Gershov

1964-01-01

208

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

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

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

209

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

PubMed

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

Vongboot, Monnapat; Suesoonthon, Monrudee

2015-01-01

210

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

PubMed

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

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

2009-09-01

211

Molecular Structure of Barium Chloride  

NSDL National Science Digital Library

Barium Chloride was the byproduct of the discovery of radium by Madame Curie. When refining radium, the final separation resulted in barium chloride and radium chloride. Electrophoresis of barium chloride produces small-scale amounts of barium atom. This can be used for obtaining barium for commercial uses. Applications of barium chloride include stimulating the heart and other muscles for medicinal purposes, and also for softening water. Other uses of barium chloride include the manufacturing of barium salts, as pesticide, pigments, boiler detergent, in purifying sugar, as mordant in dyeing and printing textiles, and in the manufacture of caustic soda, polymers, and stabilizers.

2002-08-15

212

Multiple-edge XAS studies of cyanide-bridged iron-copper molecular assemblies relevant to cyanide-inhibited heme-copper oxidases using four-body multiple-scattering analysis  

Microsoft Academic Search

A pair of cyanide-bridged iron-copper molecular assemblies relevant to cyanide-inhibited heme-copper oxidases has been studied by X-ray absorption spectroscopy at both Fe and Cu K-edges. These two complexes, [(py)(OEP)Fe-CN-Cu(Meâtren)]{sup 2+} (2) and [(py)(OEP)Fe-CN-Cu(TIM)]{sup 2+} (3), contain a unique four-body Fe-C-N-Cu bridge with an Fe-C-N angle of 179°. They, however, differ significantly in the Cu-N-C angle (174° in 2 and 147°

Hua Holly Zhang; A. Di Cicco; B. Hedman; K. O. Hodgson; A. Filipponi; M. J. Scott; R. H. Holm

1997-01-01

213

IRON  

EPA Science Inventory

The document surveys the effects of organic and inorganic iron that are relevant to humans and their environment. The biology and chemistry of iron are complex and only partially understood. Iron participates in oxidation reduction processes that not only affect its geochemical m...

214

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

PubMed

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

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

2002-11-01

215

The Crd1 gene encodes a putative di-iron enzyme required for photosystem I accumulation in copper deficiency and hypoxia in Chlamydomonas reinhardtii  

PubMed Central

Chlamydomonas reinhardtii adapts to copper deficiency by degrading apoplastocyanin and inducing Cyc6 and Cpx1 encoding cytochrome c6 and coproporphyrinogen oxidase, respectively. To identify other components in this pathway, colonies resulting from insertional mutagenesis were screened for copper- conditional phenotypes. Twelve crd (copper response defect) strains were identified. In copper-deficient conditions, the crd strains fail to accumulate photosystem I and light-harvesting complex I, and they contain reduced amounts of light-harvesting complex II. Cyc6, Cpx1 expression and plastocyanin accumulation remain copper responsive. The crd phenotype is rescued by a similar amount of copper as is required for repression of Cyc6 and Cpx1 and for maintenance of plastocyanin at its usual stoichiometry, suggesting that the affected gene is a target of the same signal transduction pathway. The crd strains represent alleles at a single locus, CRD1, which encodes a 47 kDa, hydrophilic protein with a consensus carboxylate-bridged di-iron binding site. Crd1 homologs are present in the genomes of photosynthetic organisms. In Chlamydomonas, Crd1 expression is activated in copper- or oxygen-deficient cells, and Crd1 function is required for adaptation to these conditions. PMID:10811605

Moseley, Jeffrey; Quinn, Jeanette; Eriksson, Mats; Merchant, Sabeeha

2000-01-01

216

Iron, zinc and copper in the Alzheimer’s disease brain: a quantitative meta-analysis. Some insight on the influence of citation bias on scientific opinion  

PubMed Central

Dysfunctional homeostasis of transition metals is believed to play a role in the pathogenesis of Alzheimer’s disease (AD). Although questioned by some, brain copper, zinc, and particularly iron overload are widely accepted features of AD which have led to the hypothesis that oxidative stress generated from aberrant homeostasis of these transition metals might be a pathogenic mechanism behind AD. This meta-analysis compiled and critically assessed available quantitative data on brain iron, zinc and copper levels in AD patients compared to aged controls. The results were very heterogeneous. A series of heavily cited articles from one laboratory reported a large increase in iron in AD neocortex compared to age-matched controls (p<0.0001) while seven laboratories failed to reproduce these findings reporting no significant difference between the groups (p=0.76). A more than three-fold citation bias was found to favor outlier studies reporting increases in iron and this bias was particularly prominent among narrative review articles. Additionally, while zinc was not significantly changed in the neocortex (p=0.29), copper was significantly depleted in AD (p=0.0003). In light of these findings, it will be important to re-evaluate the hypothesis that transition metal overload accounts for oxidative injury noted in AD. PMID:21600264

Schrag, Matthew; Mueller, Claudius; Oyoyo, Udochukwu; Kirsch, Wolff M.

2011-01-01

217

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

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

218

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

PubMed Central

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

Waters, Brian M.; Stein, Ricardo J.

2012-01-01

219

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

PubMed

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

Waters, Brian M; McInturf, Samuel A; Stein, Ricardo J

2012-10-01

220

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

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

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

221

The neurotoxicity of iron, copper and manganese in Parkinson's and Wilson's diseases.  

PubMed

Impaired cellular homeostasis of metals, particularly of Cu, Fe and Mn may trigger neurodegeneration through various mechanisms, notably induction of oxidative stress, promotion of ?-synuclein aggregation and fibril formation, activation of microglial cells leading to inflammation and impaired production of metalloproteins. In this article we review available studies concerning Fe, Cu and Mn in Parkinson's disease and Wilson's disease. In Parkinson's disease local dysregulation of iron metabolism in the substantia nigra (SN) seems to be related to neurodegeneration with an increase in SN iron concentration, accompanied by decreased SN Cu and ceruloplasmin concentrations and increased free Cu concentrations and decreased ferroxidase activity in the cerebrospinal fluid. Available data in Wilson's disease suggest that substantial increases in CNS Cu concentrations persist for a long time during chelating treatment and that local accumulation of Fe in certain brain nuclei may occur during the course of the disease. Consequences for chelating treatment strategies are discussed. PMID:24954801

Dusek, Petr; Roos, Per M; Litwin, Tomasz; Schneider, Susanne A; Flaten, Trond Peder; Aaseth, Jan

2014-06-01

222

Geophysical and petrophysical study of an iron oxide copper gold deposit in northern Sweden  

Microsoft Academic Search

A geophysical–petrophysical study has been performed in an area WSW of the city of Kiruna, northern Sweden. The sub-regional tectonic setting is dominated by two important shear zones, which define the boundary of a granitic body. Many Cu–Fe-occurrences are located in proximity of faults related to these major deformation zones. Particular attention has been given to the Tjårrojåkka iron oxide

Alessandro Sandrin; Sten-Åke Elming

2006-01-01

223

Mineralization of phenol in aqueous solution by ozonation using iron or copper salts and light  

Microsoft Academic Search

The degradation of aqueous phenol (100mgl?1) solutions using ozone, iron III and ultraviolet radiation has been carried out in two different devices: a laboratory installation and a pilot plant. From the results, it has been observed that mineralization of phenol solution is faster with the use of O3\\/UV\\/Fe3+ than with simple ozonation. Additionally, some experiments have shown that the substitution

Cristina Canton; Santiago Esplugas; Juan Casado

2003-01-01

224

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

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

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

1999-01-01

225

Mn2+, Ti4+ substituted barium ferrite  

Microsoft Academic Search

The substitution of iron by manganese in M-type barium ferrite BaFe12O19 has been investigated with the aim of elucidating its effect on the magnetic and magnetostrictive properties. Substitution of up to 0.4 manganese atoms per unit formula did not affect the magnetization whilst the anisotropy and magnetostriction decreased by 30% and 20%, respectively. Higher manganese contents gave rise to large

G. Turilli; F. Licci; S. Rinaldi; A. Deriu

1986-01-01

226

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

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.

Not Available

1986-09-01

227

Abundant, seasonally variable supply of glacier flour-derived iron drives high nitrate consumption in Copper River plume and adjacent Gulf of Alaska continental shelf  

Microsoft Academic Search

Recent work has suggested that high iron supply may contribute to a northward increase in phytoplankton biomass along the U.S. west coast, consistent with ``bottom-up'' control of these coastal ecosystems. We examine this hypothesis in waters of the Copper River plume and nearby continental shelf in the northern Gulf of Alaska (GoA). These are the first data we know of

J. Crusius; A. W. Schroth; R. W. Campbell; J. L. Nielsen; I. R. Hoyer; W. Brooks

2010-01-01

228

Determination of Copper, Iron, Nickel and Zinc in fuel kerosene by FAAS after adsorption and pre-concentration on 2-aminothiazole-modified silica gel  

Microsoft Academic Search

Silica gel chemically modified with 2-Aminotiazole groups, abbreviated as SiAT, was used for preconcentration of copper, zinc, nickel and iron from kerosene, normally used as a engine fuel for airplanes. Surface characteristics and surface area of the silica gel were obtained before and after chemical modification using FT-IR, Kjeldhal and surface area analysis (B.E.T.). The retention and recovery of the

P. S. Roldan; I. L. Alcântara; J. C. Rocha; C. C. F. Padilha; P. M. Padilha

2004-01-01

229

Relationship of Maternal Dietary Zinc during Gestation and Lactation to Development and Zinc, Iron and Copper Content of the Postnatal Rat '-2  

Microsoft Academic Search

High levels (0.2 and 0.5% ) of zinc were fed to adult female rats be ginning at zero-day age of the fetus and continued to day 14 of lactation to study the development and iron, copper, and zinc status of zero- and 14-day-old postnatal rats. The results were compared with rats fed a basal diet containing 9 ppm zinc. Growth

MARION R. KETCHESON; GEORGE P. BARRON; DENNIS H. COX

230

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

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

Miwa Nagae; Masaru Nakata; Yohsuke Takahashi

2008-01-01

231

Welding procedure specification: gas tungsten arc welding of nickel-copper to nickel-chromium-iron. Supplement 1. Records of procedure qualification tests  

Microsoft Academic Search

Procedure WPS-2303-ASME-3 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for gas tungsten arc welding of nickel-copper N04400 (P-42) to nickel-chromium-iron N06600 (P-43), in thickness range of 0.035 to 0.432 inch; filler metal is ERNiCu-7 (F-42); shielding gas is argon.

C. H. Wodtke; D. R. Frizzell; W. A. Plunkett

1986-01-01

232

An approach to noninvasive delivery, biodistribution, and fertility control potential evaluation of the Cuproferrogel iron oxide-copper-styrene maleic anhydride-dimethyl sulphoxide in the female.  

PubMed

Under guidance of an external pulsed magnetic field the Cuproferrogel iron oxide-copper-styrene maleic anhydride-dimethyl sulphoxide delivered into the rat/rabbit oviduct resulted in oocytes with granulated cytoplasm, zona enlargement, membrane disintegration, and finally loss of viability in 72 hours. Also, the percentage biodistribution of magnetic and electrically conductive particles observed under safe level advocates the use of Cuproferrogel as a potential female fertility control molecule. PMID:20674910

Jha, Rakhi; Jha, Pradeep K; Rana, Suresh V S; Guha, Sujoy K

2010-12-01

233

Monitoring Trace Metal Levels in Yozgat-Turkey: Copper, Iron, Nickel, Cobalt, Lead, Cadmium, Manganese and Chromium Levels in Stream Sediments  

Microsoft Academic Search

In the presented study, the concentrations of some heavy metal ions in bottom sediment samples col- lected from streams around Yozgat-Turkey in December 1998 and October 1999 were determined by flame atomic absorption spectrometry (FAAS) after leaching with aqua regia. Copper, iron, nickel, cobalt, lead, manganese and chromium levels in the sediment samples were found in the range of 10.4-16.7

M. Soylak; U. Divrikli; S. Saracoglu; L. Elci

234

Essential trace elements selenium, zinc, copper, and iron concentrations and their related acute-phase proteins in patients with vivax malaria  

Microsoft Academic Search

The aim of the present study is to evaluate the status of plasma essential trace elements selenium (Se), zinc (Zn), copper\\u000a (Cu), and iron (Fe) concentrations and their related acute-phase proteins, ceruloplasmin (Cp), ferritin, transferrin (Tf),\\u000a and albumin levels in patients with vivax malaria. Plasma Cu and Zn concentrations were determined by atomic absorption spectrometry\\u000a (AAS). Se concentrations were determined

Adnan Seyrek; Abdurrahim Kocyigit; Ozcan Erel

2005-01-01

235

Welding procedure specification: gas tungsten arc welding of nickel-copper to nickel-chromium-iron. Supplement 1. Records of procedure qualification tests  

SciTech Connect

Procedure WPS-2303-ASME-3 is qualified under Section IX of the ASME Boiler and Pressure Vessel Code for gas tungsten arc welding of nickel-copper N04400 (P-42) to nickel-chromium-iron N06600 (P-43), in thickness range of 0.035 to 0.432 inch; filler metal is ERNiCu-7 (F-42); shielding gas is argon.

Wodtke, C.H.; Frizzell, D.R.; Plunkett, W.A.

1986-06-01

236

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

PubMed Central

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

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

2014-01-01

237

Nickel-cobalt-iron-copper sulfides and arsenides in solution-collapse breccia pipes, northwestern Arizona  

SciTech Connect

An extensive suite of Ni-Co-Fe-Cu sulfides and arsenides lies within the matrix of solution-collapse breccias buried deep within the plateaus of the Grand Canyon region. Ceilings over large caverns in the Redwall collapsed, brecciating the overlying sandstone and forming cylindrical breccia pipes up to 300 ft in diameter that extend vertically as much as 3,000 ft. These highly permeable breccias served as a host for the precipitation of a suite of over 100 minerals, including uraninite, sphalerite, galena and various copper phases, in addition to the Ni-Co-bearing-phase discussed here. Intricately zoned crystals of small (<1 mm), euhedral Ni-Co-Fe-As-S minerals were the first to form during the second major episode of mineralization in these pipes. Several of these phases replace minerals, such as barite and anhydrite, from the first episode. Extensive microprobe work has been done on samples from two breccia pipe mines, the Hack 2 and Orphan, which are about 50 miles apart. Mineral compositions are similar except that no copper is found in the Ni-Co-Fe phases from the Hack 2 mine, while pyrites containing 1 wt % Cu are common from the Orphan, which was mined for copper. In some of these pyrites', Cu is dominant and the mineral is actually villamaninite. Pyrites from both mines characteristically contain 0.5 to 3 wt % As. Metal contents in zones pyrite-bravoite-vaesite (M[sub 1]S[sub 2]) crystals at the Hack 2 mine range from Fe[sub 1] to Fe[sub .12], Ni[sub 0] to Ni[sub .86], and Co[sub 0] to Co[sub .10]. The metal content for polydymite-siegenite-violarite averages about (Ni[sub 2.33]Co[sub .39]Fe[sub .23])(S[sub 3.9]As[sub .1]). Orphan mine pyrite-bravoite-vaesite-villamaninite ranges in composition from pure FeS[sub 2] to (Ni[sub .6]Fe[sub .21]Co[sub .17])S[sub 2], and (Cu[sub .46]Ni[sub .27]Fe[sub .21]Co[sub .13])S[sub 2]. Of all the sulfides or arsenides found in these breccia pipes, only nickeline consistently occurs as the pure end member.

Wenrich, K.J. (Geological Survey, Denver, CO (United States)); Hlava, P.F. (Sandia National Labs., Albuquerque, NM (United States))

1993-04-01

238

Barium Abundances in Cepheids  

E-print Network

We derived the barium atmospheric abundances for a large sample of Cepheids, comprising 270 stars. The sample covers a large range of galactocentric distances, from about 4 to 15 kpc, so that it is appropriated to investigate the existence of radial barium abundance gradients in the galactic disc. In fact, this is the first time that such a comprehensive analysis of the distribution of barium abundances in the galactic disc is carried out. As a result, we conclude that the Ba abundance distribution can be characterized by a zero gradient. This result is compared with derived gradients for other elements, and some reasons are briefly discussed for the independence of the barium abundances upon galactocentric distances.

Andrievsky, S M; Korotin, S A; Luck, R E; Kovtyukh, V V; Maciel, W J

2012-01-01

239

Transcriptomic and physiological characterization of the fefe mutant of melon (Cucumis melo) reveals new aspects of iron-copper crosstalk.  

PubMed

Iron (Fe) and copper (Cu) homeostasis are tightly linked across biology. In previous work, Fe deficiency interacted with Cu-regulated genes and stimulated Cu accumulation. The C940-fe (fefe) Fe-uptake mutant of melon (Cucumis melo) was characterized, and the fefe mutant was used to test whether Cu deficiency could stimulate Fe uptake. Wild-type and fefe mutant transcriptomes were determined by RNA-seq under Fe and Cu deficiency. FeFe-regulated genes included core Fe uptake, metal homeostasis, and transcription factor genes. Numerous genes were regulated by both Fe and Cu. The fefe mutant was rescued by high Fe or by Cu deficiency, which stimulated ferric-chelate reductase activity, FRO2 expression, and Fe accumulation. Accumulation of Fe in Cu-deficient plants was independent of the normal Fe-uptake system. One of the four FRO genes in the melon and cucumber (Cucumis sativus) genomes was Fe-regulated, and one was Cu-regulated. Simultaneous Fe and Cu deficiency synergistically up-regulated Fe-uptake gene expression. Overlap in Fe and Cu deficiency transcriptomes highlights the importance of Fe-Cu crosstalk in metal homeostasis. The fefe gene is not orthologous to FIT, and thus identification of this gene will provide clues to help understand regulation of Fe uptake in plants. PMID:24975482

Waters, Brian M; McInturf, Samuel A; Amundsen, Keenan

2014-09-01

240

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

NASA Astrophysics Data System (ADS)

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 [FeIIITMPyP]5+ molecules are reduced to the corresponding [FeIITMPyP]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 [FeIITMPyP]4+ molecules at the electrolyte/copper interface.

Phan, Thanh Hai; Wandelt, Klaus

2015-03-01

241

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

USGS Publications Warehouse

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.

Sanzolone, R.F.

1986-01-01

242

Effect of Copper and Nickel on the Transformation Kinetics of Austempered Ductile Iron  

NASA Astrophysics Data System (ADS)

The kinetics of reaction occurring during the austempering treatment of ductile iron (DI) containing different additions of Cu and Ni was investigated in this work. DI bars were heat treated in an instrumented dilatometer in order to follow the exhibited transformation kinetics. The dilatometric results indicated that the addition of Cu alone did not have a significant effect on the incubation times for the austempering transformation. Also, the addition of both, Cu and Ni resulted in a significant effect on reducing the transformation rates. It was found that the austempering process is characterized by two clearly distinguished transformation stages. In the initial stage, the addition of Cu, and to a greater extent, additions of both Cu and Ni led to reductions in the transformation rates shifting the maximum transformation rate values toward longer times. The outcome of this work indicates that during the first stage of austempering, nucleation of the ferrite plates occurs via a diffusionless mechanism while their growth is diffusion controlled. Moreover, after the maximum in the transformation rate has been reached, the growth of ferrite plates becomes dominant with the rate-limiting step becoming the diffusion of C into the surrounding austenite. A qualitative model for the austempering transformation is proposed in this work to account for the experimental observations.

Górny, Marcin; Tyra?a, Edward; Lopez, Hugo

2014-10-01

243

Effect of ultrasonic agitation on the release of copper, iron, manganese and zinc from soil and sediment using the BCR three-stage sequential extraction.  

PubMed

An ultrasonic bath and an ultrasonic probe have been used to develop rapid versions of the three-stage Community Bureau of Reference (BCR, now the Standards, Measurement and Testing Programme) sequential extraction procedure. The effect of the ultrasonic treatments on the extraction of copper, iron, manganese and zinc from a sewage sludge-amended soil has been assessed. Recoveries similar to those of conventional shaking (i.e., conventional value, +/- 30%) could generally be obtained for copper, manganese and zinc, but not for the important matrix element iron. With the use of compromise sonication conditions, steps 1, 2 and 3 of the sequential extraction (excluding the hydrogen peroxide digestion in step 3, which was not performed with sonication) could be completed in 3, 5 and 1 min, respectively, using the ultrasonic probe, and in 3, 1 and 1 h, respectively, using the bath. The extraction procedures developed using the soil performed well when applied to lake sediment BCR CRM 601. Analyte partitioning was generally similar to that obtained with mechanical shaking, and overall metal recoveries were 84-98% of those obtained with the conventional BCR protocol, except for copper extracted with the probe (74%). Poorer performance (analyte recoveries, 58-104%) was obtained when the methods were applied to an intertidal sediment. This highlights the difficulty of developing a version of the BCR extraction, with ultrasonic assistance, which gives a performance equivalent to conventional shaking when applied to different substrates. PMID:11523440

Davidson, C M; Delevoye, G

2001-08-01

244

Copper and Iron Homeostasis in Plants: The Challenges of Oxidative Stress  

PubMed Central

Abstract Significance: Photosynthesis, the process that drives life on earth, relies on transition metal (e.g., Fe and Cu) containing proteins that participate in electron transfer in the chloroplast. However, the light reactions also generate high levels of reactive oxygen species (ROS), which makes metal use in plants a challenge. Recent Advances: Sophisticated regulatory networks govern Fe and Cu homeostasis in response to metal ion availability according to cellular needs and priorities. Molecular remodeling in response to Fe or Cu limitation leads to its economy to benefit photosynthesis. Fe toxicity is prevented by ferritin, a chloroplastic Fe-storage protein in plants. Recent studies on ferritin function and regulation revealed the interplay between iron homeostasis and the redox balance in the chloroplast. Critical Issues: Although the connections between metal excess and ROS in the chloroplast are established at the molecular level, the mechanistic details and physiological significance remain to be defined. The causality/effect relationship between transition metals, redox signals, and responses is difficult to establish. Future Directions: Integrated approaches have led to a comprehensive understanding of Cu homeostasis in plants. However, the biological functions of several major families of Cu proteins remain unclear. The cellular priorities for Fe use under deficiency remain largely to be determined. A number of transcription factors that function to regulate Cu and Fe homeostasis under deficiency have been characterized, but we have not identified regulators that mediate responses to excess. Importantly, details of metal sensing mechanisms and cross talk to ROS-sensing mechanisms are so far poorly documented in plants. Antioxid. Redox Signal. 19, 919–932. PMID:23199018

Pilon, Marinus

2013-01-01

245

Solid state 31phosphorus nuclear magnetic resonance of iron-, manganese-, and copper-containing synthetic hydroxyapatites  

NASA Technical Reports Server (NTRS)

The incorporation of micronutrients into synthetic hydroxyapatite (SHA) is proposed for slow release of these nutrients to crops in the National Aeronautics and Space Administration's (NASA's) Advanced Life Support (ALS) program for Lunar or Martian outposts. Solid state 31P nuclear magnetic resonance (NMR) was utilized to examine the paramagnetic effects of Fe3+, Mn2+, and Cu2+ to determine if they were incorporated into the SHA structure. Separate Fe3+, Mn2+, and Cu2+ containing SHA materials along with a transition metal free SHA (pure-SHA) were synthesized using a precipitation method. The proximity (<1 nm) of the transition metals to the 31P nuclei of SHA were apparent when comparing the integrated 31P signal intensities of the pure-SHA (87 arbitrary units g-1) with the Fe-, Mn-, and Cu-SHA materials (37-71 arbitrary units g-1). The lower integrated 31P signal intensities of the Fe-, Mn-, and Cu-SHA materials relative to the pure-SHA suggested that Fe3+, Mn2+, and Cu2+ were incorporated in the SHA structure. Further support for Fe3+, Mn2+, and Cu2+ incorporation was demonstrated by the reduced spin-lattice relaxation constants of the Fe-, Mn-, and Cu-SHA materials (T'=0.075-0.434s) relative to pure-SHA (T1=58.4s). Inversion recovery spectra indicated that Fe3+, Mn2+, and Cu2+ were not homogeneously distributed about the 31P nuclei in the SHA structure. Extraction with diethylene-triamine-penta-acetic acid (DTPA) suggested that between 50 and 80% of the total starting metal concentrations were incorporated in the SHA structure. Iron-, Mn-, and Cu-containing SHA are potential slow release sources of Fe, Mn, and Cu in the ALS cropping system.

Sutter, B.; Taylor, R. E.; Hossner, L. R.; Ming, D. W.

2002-01-01

246

Barium and Yttrium abundance in intermediate-age and old open clusters  

E-print Network

Barium is a neutron capture element, that, in open clusters, is frequently over-abundant with respect to the Iron. A clear explanation for this is still missing. Additionally, its gradient across the Galactic disk is poorly constrained. We measure the abundance of yttrium and barium using the synthetic spectrum method from UVES high-resolution spectra of eight distant open clusters, namely Ruprecht 4, Ruprecht 7, Berkeley 25, Berkeley 73, Berkeley 75, NGC 6192, NGC 6404, and NGC 6583. The barium abundance was estimated using NLTE approximation. We confirm that Barium is indeed over-abundant in most clusters, especially young clusters. Finally, we investigated the trend of yttrium and barium abundances as a function of distance in the Galaxy and ages. Several scenarios for the barium over-abundance are then discussed.

Mishenina, T; Carraro, G; Kovtyukh, V V; Yegorova, I A

2013-01-01

247

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

PubMed

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 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. PMID:25289694

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

2014-10-21

248

Zinc, Iron, Manganese and Copper Uptake Requirement in Response to Nitrogen Supply and the Increased Grain Yield of Summer Maize  

PubMed Central

The relationships between grain yields and whole-plant accumulation of micronutrients such as zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) in maize (Zea mays L.) were investigated by studying their reciprocal internal efficiencies (RIEs, g of micronutrient requirement in plant dry matter per Mg of grain). Field experiments were conducted from 2008 to 2011 in North China to evaluate RIEs and shoot micronutrient accumulation dynamics during different growth stages under different yield and nitrogen (N) levels. Fe, Mn and Cu RIEs (average 64.4, 18.1and 5.3 g, respectively) were less affected by the yield and N levels. ZnRIE increased by 15% with an increased N supply but decreased from 36.3 to 18.0 g with increasing yield. The effect of cultivars on ZnRIE was similar to that of yield ranges. The substantial decrease in ZnRIE may be attributed to an increased Zn harvest index (from 41% to 60%) and decreased Zn concentrations in straw (a 56% decrease) and grain (decreased from 16.9 to 12.2 mg kg?1) rather than greater shoot Zn accumulation. Shoot Fe, Mn and Cu accumulation at maturity tended to increase but the proportions of pre-silking shoot Fe, Cu and Zn accumulation consistently decreased (from 95% to 59%, 90% to 71% and 91% to 66%, respectively). The decrease indicated the high reproductive-stage demands for Fe, Zn and Cu with the increasing yields. Optimized N supply achieved the highest yield and tended to increase grain concentrations of micronutrients compared to no or lower N supply. Excessive N supply did not result in any increases in yield or micronutrient nutrition for shoot or grain. These results indicate that optimized N management may be an economical method of improving micronutrient concentrations in maize grain with higher grain yield. PMID:24705926

Xue, Yanfang; Yue, Shanchao; Zhang, Wei; Liu, Dunyi; Cui, Zhenling; Chen, Xinping; Ye, Youliang; Zou, Chunqin

2014-01-01

249

Analysis of 26 Barium Stars I. Abundances  

E-print Network

We present a detailed analysis of 26 barium stars, including dwarf barium stars, providing their atmospheric parameters (Teff, log g, [Fe/H], vt) and elemental abundances. We aim at deriving gravities and luminosity classes of the sample stars, in particular to confirm the existence of dwarf barium stars. Accurate abundances of chemical elements were derived. Abundance ratios between nucleosynthetic processes, by using Eu and Ba as representatives of the r- and s-processes are presented. High-resolution spectra with the FEROS spectrograph at the ESO-1.5m Telescope, and photometric data with Fotrap at the Zeiss telescope at the LNA were obtained. The atmospheric parameters were derived in an iterative way, with temperatures obtained from colour-temperature calibrations. The abundances were derived using spectrum synthesis for Li, Na, Al, alpha-, iron peak, s- and r-elements atomic lines, and C and N molecular lines. Atmospheric parameters in the range 4300 < Teff < 6500, -1.2 < [Fe/H] < 0.0 and 1.4 < log g < 4.6 were derived, confirming that our sample contains giants, subgiants and dwarfs. The abundance results obtained for Li, Al, Na, alpha- and iron peak elements for the sample stars show that they are compatible with the values found in the literature for normal disk stars in the same range of metallicities. Enhancements of C, N and heavy elements relative to Fe, that characterise barium stars, were derived and showed that [X/Ba] vs. [Ba/H] and [X/Ba] vs. [Fe/H] present different behaviour as compared to [X/Eu] vs. [Eu/H] and [X/Eu] vs. [Fe/H], reflecting the different nucleosynthetic sites for the s- and r-processes.

Dinah M. Allen; Beatriz Barbuy

2006-04-03

250

Barium Ion Trapping Rebecca Schutzengel  

E-print Network

Barium Ion Trapping Rebecca Schutzengel Franklin W. Olin College of Engineering University of Washington INT REU August 20, 2012 Rebecca Schutzengel Barium Ion Trapping August 20, 2012 1 / 12 #12;Uses for Ion Trapping Bell's Inequality tests Quantum Computing Rebecca Schutzengel Barium Ion Trapping August

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

251

Observed Barium Emission Rates  

NASA Technical Reports Server (NTRS)

The barium releases from the CRRES satellite have provided an opportunity for verifying theoretically calculated barium ion and neutral emission rates. Spectra of the five Caribbean releases in the summer of 1991 were taken with a spectrograph on board a U.S. Air Force jet aircraft. Because the line of sight release densities are not known, only relative rates could be obtained. The observed relative rates agree well with the theoretically calculated rates and, together with other observations, confirm the earlier detailed theoretical emission rates. The calculated emission rates can thus with good accuracy be used with photometric observations. It has been postulated that charge exchange between neutral barium and oxygen ions represents a significant source for ionization. If so. it should be associated with emissions at 4957.15 A and 5013.00 A, but these emissions were not detected.

Stenbaek-Nielsen, H. C.; Wescott, E. M.; Hallinan, T. J.

1993-01-01

252

Effects of silicon, copper and iron on static and dynamic properties of alloy 206 (aluminum-copper) in semi-solids produced by the SEED process  

NASA Astrophysics Data System (ADS)

The advantages of producing metal parts by rheocasting are generally recognised for common foundry alloys of Al-Si. However, other more performing alloys in terms of mechanical properties could have a great interest in specialized applications in the automotive industry, while remaining competitive in the forming. Indeed, the growing demand for more competitive products requires the development of new alloys better suited to semi-solid processes. Among others, Al-Cu alloys of the 2XX series are known for their superior mechanical strength. However, in the past, 2XX alloys were never candidates for pressure die casting. The main reason is their propensity to hot tearing. Semi-solid processes provide better conditions for molding with the rheological behavior of dough and molding temperatures lower reducing this type of defect. In the initial phase, this research has studied factors that reduce hot tearing susceptibility of castings produced by semi-solid SEED of alloy 206. Subsequently, a comparative study on the tensile properties and fatigue was performed on four variants of the alloy 206. The results of tensile strength and fatigue were compared with the specifications for applications in the automotive industry and also to other competing processes and alloys. During this study, several metallurgical aspects were analyzed. The following main points have been validated: i) the main effects of compositional variations of silicon, iron and copper alloy Al-Cu (206) on the mechanical properties, and ii) certain relationships between the mechanism of hot cracking and the solidification rate in semi-solid. Parts produced from the semi-solid paste coming from the SEED process combined with modified 206 alloys have been successfully molded and achieved superior mechanical properties than the requirements of the automotive industry. The fatigue properties of the two best modified 206 alloys were higher than those of A357 alloy castings and are close to those of the wrought alloy AA6061. At present, there is simply no known application for pressure die-cast alloy with 206 (Liquid Die-casting). This is mainly due to the high propensity to hot cracking and limitations facing the part geometry and the subsequent assembly. This study demonstrated that in addition to pieces produced by semi-solid die-casting using large variations in chemical composition, the SEED process allows obtaining spare sound (sound part) and more complex geometry. Moreover, as the semi-solid parts have less porosity, they can also be machined and welded for some applications. The conclusions of this study demonstrate significant progress in identifying the main issues related to the feasibility of die-casting good parts with high performance using the modified 206 alloy combined with SEED process. This work is therefore a baseline work in the development of new Al-Cu alloys for industries of semi-solid and, at the same time, for the expansion of aluminum for high performance applications in the industry. N.B. This thesis is part of a research project developed by the NSERC / Rio Tinto Akan Industrial Research Chair in Metallurgy of Innovative Aluminum Transformation (CIMTAL).

Lemieux, Alain

253

Copper and Copper Proteins in Parkinson's Disease  

PubMed Central

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

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

2014-01-01

254

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

PubMed

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

Hitchen, A; Zechanowitsch, G

1980-03-01

255

Tailored Barium Swallow Study  

MedlinePLUS

Tailored Barium Swallow Study The TBS is a special study that is completed in radiology. The test evaluates the mouth and the throat ... and may be asked to feed the child. Study Participants You/Your child will drink liquids or ...

256

Semiconducting barium titanate  

Microsoft Academic Search

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

W. Heywang

1971-01-01

257

Characterization of iron- and sulphide mineral-oxidizing moderately thermophilic acidophilic bacteria from an Indonesian auto-heating copper mine waste heap and a deep South African gold mine  

Microsoft Academic Search

Iron- and chalcopyrite-oxidizing enrichment cultures were obtained at 50°C from acidic, high-temperature, copper\\/gold mine environments in Indonesia and South Africa. Over 90% copper yield was obtained from chalcopyrite concentrate with the Indonesian enrichment in 3 months with 2% solids concentration, when pH was maintained at around 2. Neither addition of silver cations nor an enhanced nutrient concentration influenced chalcopyrite leaching. Excision

Päivi H.-M. Kinnunen; Jaakko A. Puhakka

2004-01-01

258

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

NASA Astrophysics Data System (ADS)

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 in CO2-poor systems, thereby, promoting partitioning of H2O, Cl and metals to the fluid phase. At deep levels, the magma-fluid system cannot generate sufficient mechanical energy to fracture the host rocks as in porphyry systems and the IOCG deposits therefore form in a variety of fault-related structural traps where the magmatic fluids may mix with other fluids to promote ore formation. At shallow levels, the IOCG deposits form breccia and fracture-hosted mineralization styles similar to the hydrothermal intrusive breccias and sulphide vein systems that characterize many porphyry Cu-Au deposits. The fluids associated with IOCG deposits are typically H2O-CO2-salt fluids that evolve by unmixing of the carbonic phase and by mixing with fluids from other sources. In contrast, fluids in porphyry systems typically evolve by boiling of moderate salinity fluid to produce high salinity brine and a vapor phase commonly with input of externally derived fluids. These different fluid compositions and mechanisms of evolution lead to different alteration types and parageneses in porphyry and IOCG deposits. Porphyry Cu-Au deposits typically evolve through potassic, sericitic and (intermediate and/or advanced) argillic stages, while IOCG deposits typically evolve through sodic(-calcic), potassic and carbonate-rich stages, and at deeper levels, generally lack sericitic and argillic alteration. The common association of porphyry and IOCG Cu-Au deposits with potassic, oxidized intermediate to felsic granitoids, together with their contrasting fluid compositions, alteration styles and parageneses suggest that they should be considered as part of the broad family of intrusion-related systems but that they are typically not directly related to each other.

Pollard, Peter J.

2006-05-01

259

Synthesis and structural characterisation of iron(II) and copper(II) diphosphates containing flattened metal oxotetrahedra  

SciTech Connect

Single crystal and bulk polycrystalline forms of K{sub 2}MP{sub 2}O{sub 7} (M=Fe(II), Cu(II)) have been synthesised and their structures determined from single crystal X-ray diffraction data. Both compounds crystallize in the tetragonal system, space group P-42{sub 1}m. Their structures are formed from infinite sheets of linked oxopolyhedra of the stoichiometry [MP{sub 2}O{sub 7}]{sup 2?} with potassium cations situated between the layers. The MO{sub 4} tetrahedra share oxygen atoms with [P{sub 2}O{sub 7}]{sup 4?} diphosphate groups and the potassium ions have KO{sub 8} square prismatic geometry. In both compounds the M(II) centre has an unusual strongly flattened, tetrahedral coordination to oxygen, as a result of the Jahn–Teller (JT) effect for the high spin d{sup 6} Fe(II) and p-orbital mixing or a second order JT effect for d{sup 9} Cu(II) centres in four fold coordination. The uncommon transition metal ion environments found in these materials are reflected in their optical absorption spectra and magnetism data. - Graphical abstract: The structures of the tetragonal polymorphs of K{sub 2}MP{sub 2}O{sub 7}, M=Cu(II), Fe(II), consist of infinite sheets of stoichiometry [MP{sub 2}O{sub 7}]{sup 2?}, formed from linked pyrophosphate groups and MO{sub 4} tetrahedra, separated by potassium ions. In both compounds the unusual tetrahedral coordination of the M(II) centre is strongly flattened as a result of Jahn–Teller (JT) effects for high spin, d{sup 6} Fe(II) and p-orbital mixing and second-order JT effects for d{sup 9} Cu(II). Display Omitted - Highlights: • Tetrahedral copper and iron(II) coordinated by oxygen. • New layered phosphate structure. • Jahn–Teller and d{sup 10} distorted coordinations.

Keates, Adam C. [School of Chemistry, University of Southampton, Southampton, Hampshire SO17 1B,. UK (United Kingdom); Wang, Qianlong [Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY (United Kingdom); Weller, Mark T., E-mail: m.t.weller@bath.ac.uk [Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY (United Kingdom)

2014-02-15

260

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)

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.

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

2014-08-01

261

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

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

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

262

Catalytic and inhibiting effects of barium peroxide and hydroxide on the decomposition of sodium chlorate  

Microsoft Academic Search

The thermal decomposition of sodium chlorate catalyzed by manganese(IV) oxide, nickel(II) oxide and copper(II) oxide in the presence of barium peroxide or hydroxide has been studied by thermogravimetric and differential thermal analysis. Barium peroxide and hydroxide are moderately active catalysts when used alone, but both become inhibitors for the decomposition of sodium chlorate catalyzed by manganese(IV) oxide, nickel(II) oxide and

Yunchang Zhang; Girish Kshirsagar; John E. Ellison; James C. Cannon

1995-01-01

263

Effects of microbial iron reduction and oxidation on the immobilization and mobilization of copper in synthesized Fe(III) minerals and Fe-rich soils.  

PubMed

The effects of microbial iron reduction and oxidation on the immobilization and mobilization of copper were investigated in a high concentration of sulfate with synthesized Fe(III) minerals and red earth soils rich in amorphous Fe (hydr)oxides. Batch microcosm experiments showed that red earth soil inoculated with subsurface sediments had a faster Fe(III) bioreduction rate than pure amorphous Fe(III) minerals and resulted in quicker immobilization of Cu in the aqueous fraction. Coinciding with the decrease of aqueous Cu, SO4(2-) in the inoculated red earth soil decreased acutely after incubation. The shift in the microbial community composite in the inoculated soil was analyzed through denaturing gradient gel electrophoresis. Results revealed the potential cooperative effect of microbial Fe(III) reduction and sulfate reduction on copper immobilization. After exposure to air for 144 h, more than 50% of the immobilized Cu was remobilized from the anaerobic matrices; aqueous sulfate increased significantly. Sequential extraction analysis demonstrated that the organic matter/sulfide-bound Cu increased by 52% after anaerobic incubation relative to the abiotic treatment but decreased by 32% after oxidation, indicating the generation and oxidation of Cu-sulfide coprecipitates in the inoculated red earth soil. These findings suggest that the immobilization of copper could be enhanced by mediating microbial Fe(III) reduction with sulfate reduction under anaerobic conditions. The findings have an important implication for bioremediation in Cucontaminated and Fe-rich soils, especially in acid-mine-drainage-affected sites. PMID:24448165

Hu, Chaohua; Zhang, Youchi; Zhang, Lei; Luo, Wensui

2014-04-01

264

A spectrophotometric method to determine the siderophore production by strains of fluorescent Pseudomonas in the presence of copper and iron  

Microsoft Academic Search

A simple procedure to determine levels of siderophore production by strains of Pseudomonas, particularly the Avm strain is described. Bacterial cells were incubated for 24 h in iron-rich (RM) and iron-limiting conditions (RM-Fe) with and without 6 and 60 ?M of CuSO4. Cells grown under iron-limiting conditions developed a green color even in the presence of Cu. The spent media

Guillermo Carrillo-Castañeda; Juana Juárez Muñoz; Jose R. Peralta-Videa

2005-01-01

265

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)

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.

Farren, Jeffrey David

266

Silicosis in barium miners.  

PubMed Central

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

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

1986-01-01

267

75 FR 33824 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013, 2014

...No. 731-TA-149 (Third Review)] Barium Chloride From China Determination On the...revocation of the antidumping duty order on barium chloride from China would be likely to...Publication 4157 (June 2010), entitled Barium Chloride from China: Investigation...

2010-06-15

268

75 FR 19657 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013, 2014

...No. 731-TA-149 (Third Review)] Barium Chloride From China AGENCY: United States...concerning the antidumping duty order on barium chloride from China...revocation of the antidumping duty order on barium chloride from China would be likely...

2010-04-15

269

Properties of Semiconductive Barium Titanates  

Microsoft Academic Search

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.

Osamu Saburi

1959-01-01

270

The barium iron ruthenium oxide system  

NASA Technical Reports Server (NTRS)

In the system BaFe(1-x)Ru(x)O(3-y), three phases, separated by immiscibility gaps, are present: an Fe-rich phase (x = 0 to 0.75) with hexagonal BaTiO3 structure (6H; sequence (hcc)2), a Ru-rich phase (x = 0.9) of hexagonal 4H-type (sequence (hc)2), and the pure Ru compounds BaRuO3 with rhombohedral 9R structure (sequence (hhc)3). By vibrational spectroscopic investigations in the 6H phase a transition from n-type semiconduction (Fe-rich compounds with complete O lattice) can be detected. The 4H and 9R stacking polytypes are good, metal-like conductors. The lattice parameters are given.

Kemmler-Sack, S.; Ehmann, A.

1986-01-01

271

Entrainment behavior of copper and copper matte in copper smelting operations  

Microsoft Academic Search

In copper smelting, the loss of copper to the slag due to entrainment is largely influenced by the flotation of copper metal\\u000a and\\/or matte in the slag phase. To evaluate this behavior, the surface tension of copper as a function of temperature and\\u000a oxygen pressure and the interfacial tension of the copper-iron matte-slag system as a function of matte grade

S. W. Ip; J. M. Toguri

1992-01-01

272

Liver concentrations of copper, zinc, iron and molybdenum in sheep and goats from northern Greece, determined by energy-dispersive x-ray fluorescence spectrometry.  

PubMed

Energy-dispersive X-Ray fluorescence spectrometry was used to determine the concentrations of copper (Cu), zinc, iron and molybdenum in the liver of 76 sheep and goats from the regions of Macedonia-Thrace, northern Greece. In general, metal concentrations were in the adequate range, with one main exception of Cu-deficiency observed in all of the examined goat liver samples and Cu-toxicity found in 4 % of the sheep liver samples. One-way analysis of variance was carried out to determine significant differences among means depending on animal species, sex and age. Pearson correlation analysis was used to explore correlations between metal concentrations. The results obtained in the present study are discussed in the framework of diagnostic ranges, suggested for classifying the metal status of sheep and goats, and are compared with liver metal concentrations reported world-wide. PMID:25694162

Papachristodoulou, Christina; Stamoulis, Konstantinos; Tsakos, Panagiotis; Vougidou, Christina; Vozikis, Vasileios; Papadopoulou, Chrissanthy; Ioannides, Konstantinos

2015-04-01

273

The influence of the production technology of iron-copper composite alloy on its erosion properties in a high-current high-pressure arc  

NASA Astrophysics Data System (ADS)

The electrical erosion properties of material based on a pseudo-alloy of copper and iron CuFe (85/15%) obtained by layered cladding are compared with the erosion of CuW (25/75%) and CuFe (70/30%) obtained by conventional powder alloying. Erosion of electrodes has been measured for arcs in the range of current amplitudes from 50 to 150 kA at an air pressure from 20 Pa to 2 MPa. Specific erosion has been determined as a function of current and gas pressure. The specific erosion of the new material is ˜1 mg/C at the level of materials produced by conventional powder technology.

Budin, A. V.; Pinchuk, M. E.; Kuznetsov, V. E.; Rutberg, F. G.

2014-12-01

274

Barium uranyl diphosphonates  

SciTech Connect

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.

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

275

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

SciTech Connect

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.

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

276

Evaluating In-Situ Reactions of Chlorine and Chloramines at the Surface of Copper and Iron using Microelectrodes  

EPA Science Inventory

Corrosion of drinking water plumbing materials is a significant cause of deterioration of treated drinking water quality and a failure to supply safe water to the public. As a result of the Lead and Copper Rule, many water utilities in the US have developed and evaluated corrosio...

277

Studies of concentration and temperature dependences of precipitation kinetics in iron-copper alloys using kinetic Monte Carlo and stochastic statistical simulations  

SciTech Connect

The previously developed ab initio model and the kinetic Monte Carlo method (KMCM) are used to simulate precipitation in a number of iron-copper alloys with different copper concentrations x and temperatures T. The same simulations are also made using an improved version of the previously suggested stochastic statistical method (SSM). The results obtained enable us to make a number of general conclusions about the dependences of the decomposition kinetics in Fe-Cu alloys on x and T. We also show that the SSM usually describes the precipitation kinetics in good agreement with the KMCM, and using the SSM in conjunction with the KMCM allows extending the KMC simulations to the longer evolution times. The results of simulations seem to agree with available experimental data for Fe-Cu alloys within statistical errors of simulations and the scatter of experimental results. Comparison of simulation results with experiments for some multicomponent Fe-Cu-based alloys allows making certain conclusions about the influence of alloying elements in these alloys on the precipitation kinetics at different stages of evolution.

Khromov, K. Yu.; Vaks, V. G., E-mail: vaks@mbslab.kiae.ru; Zhuravlev, I. A. [National Research Center 'Kurchatov Institute' (Russian Federation)] [National Research Center 'Kurchatov Institute' (Russian Federation)

2013-02-15

278

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)

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.

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

2005-04-01

279

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

PubMed

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

Shih, Kaimin

2012-12-01

280

Environmental application of millimeter-scale sponge iron (s-Fe(0)) particles (II): The effect of surface copper.  

PubMed

To enhance the catalytic reactivity of millimeter-scale particles of sponge iron (s-Fe(0)), Cu(2+) ions were deposited on the surface of s-Fe(0) using a simple direct reduction reaction, and the catalytic properties of the bimetallic system was tested for removal of rhodamine B (RhB) from an aqueous solution. The influence of Cu(0) loading, catalyst dosage, particle size, initial RhB concentration, and initial pH were investigated, and the recyclability of the catalyst was also assessed. The results demonstrate that the 3?5 millimeter s-Fe(0) particles (s-Fe(0)(3?5mm)) with 5wt% Cu loading gave the best results. The removal of RhB followed two-step, pseudo-first-order reaction kinetics. Cu(0)-s-Fe(0) showed excellent stability after five reuse cycles. Cu(0)-s-Fe(0) possesses great advantages compared to nanoscale zero-valent iron, iron power, and iron flakes as well as its bimetals. The surface Cu(0) apparently catalyzes the production of reactive hydrogen atoms for indirect reaction and generates Fe-Cu galvanic cells that enhance electron transfer for direct reaction. This bimetallic catalyst shows great potential for the pre-treatment of recalcitrant wastewaters. Additionally, some oxides containing iron element are selected to simulate the adsorption process. The results prove that the adsorption process of FeOOH, Fe2O3 and Fe3O4 played minor role for the removal of RhB. PMID:25668301

Ju, Yongming; Liu, Xiaowen; Liu, Runlong; Li, Guohua; Wang, Xiaoyan; Yang, Yanyan; Wei, Dongyang; Fang, Jiande; Dionysiou, Dionysios D

2015-04-28

281

Multiple-edge XAS studies of cyanide-bridged iron-copper molecular assemblies relevant to cyanide-inhibited heme-copper oxidases using four-body multiple-scattering analysis  

SciTech Connect

A pair of cyanide-bridged iron-copper molecular assemblies relevant to cyanide-inhibited heme-copper oxidases has been studied by X-ray absorption spectroscopy at both Fe and Cu K-edges. These two complexes, [(py)(OEP)Fe-CN-Cu(Me{sub 6}tren)]{sup 2+} (2) and [(py)(OEP)Fe-CN-Cu(TIM)]{sup 2+} (3), contain a unique four-body Fe-C-N-Cu bridge with an Fe-C-N angle of 179{degree}. They, however, differ significantly in the Cu-N-C angle (174{degree} in 2 and 147{degree} in 3). We have calculated theoretical four-body MS signals for the bridge configuration and other four-body pathways in the structures, and performed least-square fittings of the theoretical signals to the experimental data using the GNXAS programs. A strong long-range Fe...Cu interaction (4.94 A) has been observed from both the Fe and Cu K-edge data for 2. GNXAS analysis shows that this long-range interaction is attributed to the MS amplitude enhancement form the linear four-body Fe-C-N-Cu configuration. This interaction is not observable from the Fe and Cu K-edge data for 3 where the angle deviates significantly from linearity. An angle-dependence study of MS effects on the Cu-N-C angle shows that there is a large enhancement of MS intensity where the angle approaches linearity, and that this MS effect is negligible when the angle is below nearly 160{degree}. Essentially no Fe-Cu interaction is detectable for a configuration with such an angle. 33 refs., 11 figs., 2 tabs.

Zhang, H.H.; Di Cicco, A.; Hedman, B.; Hodgson, K.O. [Stanford Univ., CA (United States)] [Stanford Univ., CA (United States); Filipponi, A. [European Synchrotron Radiation Facility, Grenoble (France)] [European Synchrotron Radiation Facility, Grenoble (France); Scott, M.J.; Holm, R.H. [Harvard Univ., Cambridge, MA (United States)] [Harvard Univ., Cambridge, MA (United States)

1997-03-12

282

Discovery of the Barium Isotopes  

E-print Network

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.

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

2009-08-13

283

Discovery of the barium isotopes  

SciTech Connect

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

Shore, A.; Fritsch, A.; Ginepro, J.Q.; Heim, M.; Schuh, A. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Thoennessen, M., E-mail: thoennessen@nscl.msu.ed [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

2010-11-15

284

Built-Up Films of Barium Stearate and Their Optical Properties  

Microsoft Academic Search

The technique of depositing successive single layers of molecules of various stearates on a solid surface is described. Films containing 3001 layers have been built of barium-copper stearate. A photograph shows films built in a series of steps having intervals of 2 molecular layers. The contrast of the steps is plainly visible when the slide is illuminated by polarized light

Katharine B. Blodgett; Irving Langmuir

1937-01-01

285

FLAME SPECTROPHOTOMETRIC STUDY OF BARIUM  

Microsoft Academic Search

Flame emission characteristics of the barium ionic doublet at 455.4 and ; 4193.4 m mu , the atomic resonance line at 553.6 m mu , and the BaOH and BaO ; bands at 489 and 513 m mu were studied. A prism flame spectrophotometer ; (Beckman DU) and a grating type (Jarrell-Ash Ebert) were used. Barium ; concentrations ranged from

J. C. Burger; T. C. Rains; H. E. Zittel; J. A. Dean

1961-01-01

286

Large-volume barium aspiration.  

PubMed

We present a case of large-volume barium aspiration in a 56-year-old woman with stage IV tongue squamous cell carcinoma and longstanding dysphagia. The patient rapidly developed hypoxemic respiratory failure from the resultant chemical pneumonitis. However, her respiratory status improved with supportive care alone in 48 hours. Barium aspiration is rare and often produces dramatic radiographic findings, but is generally associated with a favorable prognosis. PMID:25829647

Hundemer, Gregory L; Kumar, Varun; Vaduganathan, Muthiah

2015-04-01

287

Large-volume barium aspiration  

PubMed Central

We present a case of large-volume barium aspiration in a 56-year-old woman with stage IV tongue squamous cell carcinoma and longstanding dysphagia. The patient rapidly developed hypoxemic respiratory failure from the resultant chemical pneumonitis. However, her respiratory status improved with supportive care alone in 48 hours. Barium aspiration is rare and often produces dramatic radiographic findings, but is generally associated with a favorable prognosis. PMID:25829647

Hundemer, Gregory L.; Kumar, Varun

2015-01-01

288

Barium light source method and apparatus  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

289

Abundance analysis of barium and mild barium stars  

E-print Network

High signal to noise, high resolution spectra were obtained for a sample of normal, mild barium, and barium giants. Atmospheric parameters were determined from the FeI and FeII lines. Abundances for Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, and Gd, were determined from equivalent widths and model atmospheres in a differential analysis, with the red giant Eps Vir as the standard star. The different levels of s-process overabundances of barium and mild barium stars were earlier suggested to be related to the stellar metallicity. Contrary to this suggestion, we found in this work no evidence of barium and mild barium to having different range in metallicity. However, comparing the ratio of abundances of heavy to light s-process elements, we found some evidence that they do not share the same neutron exposure parameter. The exact mechanism controlling this difference is still not clear. As a by-product of this analysis we identify two normal red giants misclassified as mild barium stars. The relevance of this finding is discussed. Concerning the suggested nucleosynthetic effects possibly related to the s-process, for elements like Cu, Mn, V and Sc, we found no evidence for an anomalous behavior in any of the s-process enriched stars analyzed here. However, further work is still needed since a clear [Cu/Fe] vs. [Ba/H] anticorrelation exists for other s-process enriched objects.

R. Smiljanic; G. F. Porto de Mello; L. da Silva

2007-04-02

290

Oxidative DNA damage mediated by copper(II), iron(II) and nickel(II) Fenton reactions: evidence for site-specific mechanisms in the formation of double-strand breaks, 8-hydroxydeoxyguanosine and putative intrastrand cross-links  

Microsoft Academic Search

The role of metal ion–DNA interactions in the Fenton reaction-mediated formation of putative intrastrand cross-links, 8-hydroxydeoxyguanosine (8-OHdG) and single- and double-strand breaks was investigated. Salmon sperm DNA and pBluescript K+ plasmid were incubated with hydrogen peroxide and either copper(II), iron(II), or nickel(II), which differ in both their affinity for DNA and in the spectrum of oxidative DNA damage they induce

Daniel R Lloyd; David H Phillips

1999-01-01

291

Barium and CH Stars The classical barium (or ``Ba II'') stars are red  

E-print Network

Barium and CH Stars The classical barium (or ``Ba II'') stars are red giants whose spectra show strong absorption lines of barium, strontium, and certain other heavy elements, as well as strong transfer in binary sys­ tems that drastically alters the surface compo­ sition of a companion star. Barium

Bond, Howard E.

292

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

PubMed

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

Nagae, Miwa; Nakata, Masaru; Takahashi, Yohsuke

2008-04-01

293

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

PubMed Central

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

Nagae, Miwa; Nakata, Masaru; Takahashi, Yohsuke

2008-01-01

294

Effects of Partial Replacement of Iron with Tungsten on Microstructure, Electrical, Magnetic and Humidity Properties of Copper-Zinc Ferrite Material  

NASA Astrophysics Data System (ADS)

This paper presents the analysis of the influence of partial replacement of iron with tungsten on the properties of copper-zinc spinel ferrite material. The samples of Cu0.5Zn0.5W x Fe2- x O4 spinel powder ferrites were prepared by using a sol-gel self-combustion technology. The ferrite samples were treated for 30 min at 1000°C. The x-ray diffraction was used in order to establish the differences between the phase compositions of ferrites with different tungsten content. Scanning electron microscopy was used to highlight the influence of the tungsten content on the crystallites. All the samples of Cu0.5Zn0.5W x Fe2- x O4 were subject to investigation of the influence of the substitution of tungsten upon their electrical and magnetic properties. The measurements of the electrical properties were performed in different humidity conditions, in order to highlight the effect of moisture conditions on the electrical properties of the material and to analyze the applicability of Cu0.5Zn0.5W x Fe2- x O4 ferrite for resistive or capacitive humidity sensors.

Tudorache, Florin; Petrila, Iulian

2014-09-01

295

Simultaneous coprecipitation of lead, cobalt, copper, cadmium, iron and nickel in food samples with zirconium(IV) hydroxide prior to their flame atomic absorption spectrometric determination.  

PubMed

A simple and new coprecipitation procedure is developed for the determination of trace quantities of heavy metals (lead, cobalt, copper, cadmium, iron and nickel) in natural water and food samples. Analyte ions were coprecipitated by using zirconium(IV) hydroxide. The determination of metal levels was performed by flame atomic absorption spectrometry (FAAS). The influences of analytical parameters including pH, amount of zirconium(IV), sample volume, etc. were investigated on the recoveries of analyte ions. The effects of possible matrix ions were also examined. The recoveries of the analyte ions were in the range of 95-100%. Preconcentration factor was calculated as 25. The detection limits for the analyte ions based on 3 sigma (n=21) were in the range of 0.27-2.50 microgL(-1). Relative standard deviation was found to be lower than 8%. The validation of the presented coprecipitation procedure was performed by the analysis certified reference materials (GBW 07605 Tea and LGC 6010 Hard drinking water). The procedure was successfully applied to natural waters and food samples like coffee, fish, tobacco, black and green tea. PMID:19539005

Citak, Demirhan; Tuzen, Mustafa; Soylak, Mustafa

2009-09-01

296

Volume 7. Copper base powder metallurgy  

SciTech Connect

This book is based on a series of lectures on copper and copper base P/M materials sponsored by the Metal Powder Industries Federation. It covers recent developments in the fields of copper powder metallurgy and offers a comprehensive survey of copper and copper-base P/M materials. It begins with a chapter on the production of copper and copper alloy powders followed by discussions of specific applications of P/M materials in bronzes and bearings, in brasses and nickel silvers, and in electrically conductive parts. Also discussed are iron composition containing copper, copper-based alloys for infiltration of iron and other special copper-base alloys. It concludes with chapters on consolidation, sintering and review of specifications.

Taubenblat, P.W. (ed.)

1980-01-01

297

Hydrogen bonding of sulfur ligands in blue copper and iron-sulfur proteins: detection by resonance raman spectroscopy  

SciTech Connect

The resonance Raman spectrum of the blue copper protein azurin from Alcaligenes denitrificans exhibits nine vibrational modes between 330 and 460 cm/sup -1/, seven of which shift 0.4-3.0 cm/sup -1/ to lower energy after incubation of the protein in D/sub 2/O. These deuterium-dependent shifts have been previously ascribed to exchangeable protons on imidazole ligands or to exchangeable protons on amide groups which are hydrogen bonded to the cysteine thiolate ligands (a feature common to all blue copper proteins of known structure). In order to distinguish between these two possibilities, a systematic investigation of Fe/sub 2/S/sub 2/(Cys)/sub 4/-containing proteins was undertaken. Extensive hydrogen bonding between sulfur ligands and the polypeptide backbone had been observed in the crystal structure of ferredoxin from Spirulina platensis. The resonance Raman spectrum of this protein is typical of a chloroplast-type ferredoxin and exhibits deuterium-dependent shifts of -0.3 to -0.5 cm/sup -1/ in the Fe-S modes at 283, 367, and 394 cm/sup -1/ and -0.6 to -0.8 cm/sup -1/ in the Fe-S modes at 328 and 341 cm/sup -1/. Considerably greater deuterium sensitivity is observed in the Raman spectra of spinach ferredoxin and bovine adrenodoxin, particularly for the symmetric stretching vibration of the Fe/sub 2/S/sub 2/ moiety at approx. 390 cm/sup -1/. This feature decreases of 9.8 and 1.1 cm/sup -1/, respectively, for the two oxidized proteins in D/sub 2/O and by 1.8 cm/sup -1/ for reduced adrenodoxin in D/sub 2/O. These results suggest that the bridging sulfido groups may be more extensively hydrogen bonded in spinach ferredoxin and adrenodoxin than in S. platensis ferredoxin, with a further increase in hydrogen-bond strength in the reduced form of adrenodoxin.

Mino, Y.; Loehr, T.M.; Wada, K.; Matsubara, H.; Sanders-Loehr, J.

1987-12-15

298

Fully-Ionized Barium Plasma Source  

Microsoft Academic Search

A device for generating a fully-ionized barium plasma column is described. It is similar to the previously described Q1 device except for the substitution of rhenium ionizing surfaces for tungsten, and barium for the alkali metals. The main motivation for the use of barium is that singly-ionized barium has its resonance lines in the visible wavelength range, and thus allows

N. Rynn; E. Hinnov; L. C. Johnson

1967-01-01

299

Barium Ions for Quantum Computation Matthew Dietrich  

E-print Network

Barium Ions for Quantum Computation Matthew Dietrich A dissertation submitted in partial of the manuscript made from microform." Signature Date #12;#12;University of Washington Abstract Barium Ions Department of Physics Barium ion is investigated as a hyperfine qubit. 137Ba+ is trapped in a linear Paul

Blinov, Boris

300

Quantum manipulation on the Barium quadrupolar transition  

E-print Network

Quantum manipulation on the Barium quadrupolar transition A diploma thesis in physics submitted and stabilization of a new fiber laser system to ma- nipulate the Barium quadrupolar transition, with the aim with a single Barium ion trapped in a linear Paul trap and Doppler cooled to the Lamb Dicke regime. The narrow

Blatt, Rainer

301

Computer modelling of barium titanate  

Microsoft Academic Search

Barium titanate is an important material for both scientific and industrial applications. Much of the interest centres around its ferroelectric properties, since it is structurally the most simple in this class. In addition rare-earth doped ceramics are found to exhibit a very steep positive temperature coefficient of resistance (PTCR) above the Curie point. The theory of this PTCR effect is

G. V. Lewis; C. R. A. Catlow

1983-01-01

302

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)

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.

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

2007-07-01

303

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

SciTech Connect

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.

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

304

Di-, tetra- and hexanuclear iron(III), manganese(II/III) and copper(II) complexes of Schiff-base ligands derived from 6-substituted-2-formylphenols.  

PubMed

Acyclic Schiff base ligands, derived from the condensation of 2,3-disubstituted benzaldehydes and 1,3-diaminopropan-2-ol, react with iron(II/III), manganese(II/III) and copper(II) salts to give di-, tetra- and hexanuclear complexes [Fe(III)(2)(L5)(2)].2MeOH (), [Fe(III)(4)(mu(3)-OMe)(2)(HL4)(2)Cl(2)] (), [Mn(II)(2)Mn(III)(2)(micro-OMe)(2)(HL4)(2)(DMF)(2)].2DMF () and [Cu(II)(6)(L5)(2)(micro(5)-SO(4))(2)(micro-SO(4))(MeOH)(2)].H(2)O.15.5(MeOH).15.5(MeCN) (). All compounds have been characterised by X-ray crystallography. Variable-temperature solid-state dc magnetisation studies have been performed in the temperature range 1.8-300 K. Antiferromagnetic interactions are present in all the compounds. The dinuclear compound has a zero total spin ground state with J = -9.66(1) cm(-1) and g = 2.07(1). The magnetic data for the tetranuclear compounds and have been interpreted using a tetranuclear butterfly model (b = body, w = wingtip) with the parameters: J(wb) = -9.35(4) cm(-1), J(bb) = -6.02(7) cm(-1), zJ' = -0.21(4) cm(-1) and g = 2.03(1) for ; and J(wb) = -3.40(3) cm(-1), J(bb) = -8.11(7) cm(-1), zJ' = -0.042(2) cm(-1) and g = 2.0 (fixed) for . The hexanuclear compound contains two {Cu(3)(L5)(MeOH)} units linked by three sulfate ligands: antiferromagnetic interactions are present in each trinuclear unit leading to two S = 1/2 motifs which do not or only very weakly interact across the sulfate bridges. PMID:19240905

Lan, Yanhua; Novitchi, Ghenadie; Clérac, Rodolphe; Tang, Jin-Kui; Madhu, N T; Hewitt, Ian J; Anson, Christopher E; Brooker, Sally; Powell, Annie K

2009-03-14

305

Synthesis, characterization, and spectroscopic investigation of new iron(III) and copper(II) complexes of a carboxylate rich ligand and their interaction with carbohydrates in aqueous solution.  

PubMed

New tetra-iron(III) (K4[1]·25H2O·(CH3)2CO and K3[2]·3H2O·(OH)) and di-copper(II) (Na3[3]·5H2O) complexes as carbohydrate binding models have been synthesized and fully characterized used several techniques including single crystal X-ray crystallography. Whereas K4[1]·25H2O·(CH3)2CO and Na3[3]·5H2O are completely water-soluble, K3[2]·3H2O·(OH) is less soluble in all common solvents including water. The binding of substrates, such as d-mannose, d-glucose, d-xylose, and xylitol with the water-soluble complexes in different reaction conditions were investigated. In aqueous alkaline media, complexes K4[1]·25H2O·(CH3)2CO and Na3[3]·5H2O showed coordination ability toward the applied substrates. Even in the presence of stoichiometric excess of the substrates, the complexes form only 1:1 (complex/substrate) molar ratio species in solution. Apparent binding constants, pKapp, values between the complexes and the substrates were determined and specific mode of substrate binding is proposed. The pKapp values showed that d-mannose coordinates strongest to K4[1]·25H2O·(CH3)2CO and Na3[3]·5H2O. Syntheses, characterizations and detailed substrate binding study using spectroscopic techniques and single crystal X-ray diffraction are reported. PMID:25299480

Stewart, Christopher D; Arman, Hadi; Bawazir, Huda; Musie, Ghezai T

2014-10-20

306

Flame spectra of copper salts  

Microsoft Academic Search

]NTRODUCTION COPPER SALTS, specially the halides, like so many other salts of alkalire earths and iron group, from their natural colours and the co]ours which they impart to the flames in which they are introdueed, have been drawing the attention of workers from very early times. Most of the copper salts, when put into a flame, give a yellowish luminescence

Nand Lal Singh

1947-01-01

307

Characterization of iron- and sulphide mineral-oxidizing moderately thermophilic acidophilic bacteria from an Indonesian auto-heating copper mine waste heap and a deep South African gold mine.  

PubMed

Iron- and chalcopyrite-oxidizing enrichment cultures were obtained at 50 degrees C from acidic, high-temperature, copper/gold mine environments in Indonesia and South Africa. Over 90% copper yield was obtained from chalcopyrite concentrate with the Indonesian enrichment in 3 months with 2% solids concentration, when pH was maintained at around 2. Neither addition of silver cations nor an enhanced nutrient concentration influenced chalcopyrite leaching. Excision and sequencing of bands from denaturing gradient gel electrophoresis of the amplified partial 16S rRNA gene showed that the enrichment cultures from different environments in South Africa and Indonesia were very simple, and similar. Chalcopyrite concentrate supported a simpler and different community than Fe2+. The members of the enrichment cultures were closely related to Sulfobacillus yellowstonensis and Sulfobacillus acidophilus. PMID:15309637

Kinnunen, Päivi H-M; Puhakka, Jaakko A

2004-10-01

308

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 Central

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

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

309

Copper Test  

MedlinePLUS

... page: Was this page helpful? Also known as: Cu; 24-hour urine copper; Total copper; Non-ceruloplasmin-bound copper; Free copper; Hepatic copper Formal name: Copper (24-hour urine, total and free blood, and hepatic) Related tests: Ceruloplasmin ; Heavy Metals At a Glance Test Sample The Test Common ...

310

X-ray and neutron diffraction studies on iron-substituted Z-type hexagonal barium ferrite: Ba 3Co 2? x Fe 24+ x O 41 ( x=0–0.6)  

Microsoft Academic Search

Z-type hexagonal ferrite samples in which cobalt are partially substituted with iron, Ba3Co2?xFe24+xO41 (x=0, 0.2, 0.4, 0.6), were prepared by the ceramics process under a sintering oxygen partial pressure, PO2=21.3or101.3kPa, at 1573K. The influence of the substitution ratio and oxygen partial pressure on the complex permeability was investigated by examining the cobalt distribution over various cation sites in the Z-type

T. Tachibana; T. Nakagawa; Y. Takada; K. Izumi; T. A Yamamoto; T. Shimada; S. Kawano

2003-01-01

311

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

312

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

313

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

314

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2014 CFR

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

2014-07-01

315

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 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...

2010-07-01

316

Investigations on Barium Ferrite Magnets  

Microsoft Academic Search

Barium ferrite (BaO:6Fe2O3) has been investigated magnetically to test the predictions of fine particle theory in the region of grain sizes larger than the critical one for which no satisfactory theory exists as yet. Grain size and coercive force of polycrystalline magnets (nonoriented and crystal oriented) were closely related to sintering temperatures. A comparison of theoretical and observed temperature dependence

K. J. Sixtus; K. J. Kronenberg; R. K. Tenzer

1956-01-01

317

The problem of the barium stars  

NASA Technical Reports Server (NTRS)

Ultraviolet observations of barium stars and other cool stars with peculiar element abundances are reported. Those observations attempted to find hot white dwarf companions. Among six real barium stars studied, only Zeta Cap was found to have a white dwarf companion. Among seven mild, or marginal, barium stars studied, at least three were found to have hot subluminous companions. It is likely that all of them have white dwarf companions.

Bohm-Vitense, E.; Nemec, J.; Proffitt, C.

1984-01-01

318

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

E-print Network

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]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.

Roederer, Ian U

2012-01-01

319

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

E-print Network

sampling data yielded some surprising results. These results indicated potentially high occupational exposures to lead and copper while antimony, cadmium, and barium were not detected. This was startling considering previous research indicated the potential...

Pickard, David Paul

1996-01-01

320

Noble gas and halogen constraints on fluid sources in iron oxide-copper-gold mineralization: Mantoverde and La Candelaria, Northern Chile  

NASA Astrophysics Data System (ADS)

The noble gas (Ar, Kr, Xe) and halogen (Cl, Br, I) composition of fluid inclusions in hydrothermal quartz and calcite related to the hypogene iron oxide-copper-gold (IOCG) mineralization at Mantoverde and Candelaria, Chile, have been investigated to provide new insights of fluid and salinity sources in Andean IOCG deposits. A combination of mechanical extraction by crushing and thermal decrepitation methods was applied and collectively indicate that fluid inclusions with salinities ranging from 3.4 up to 64 wt% NaCl equivalent have molar Br/Cl and I/Cl ratios of between 0.5 × 10-3 and 3.0 × 10-3 and I/Cl of between 8 × 10-6 and 25 × 10-6 in the majority of samples, with maximum values of 5.2 × 10-3 obtained for Br/Cl and 64 × 10-6 for I/Cl in fluid inclusions within individual samples. The fluid inclusions have age-corrected 40Ar/36Ar ratios ranging from the atmospheric value of 296 up to 490 ± 45, indicating the presence of crustal- or mantle-derived excess 40Ar in the fluid inclusions of most samples. The fluid inclusions have 84Kr/36Ar and 130Xe/36Ar ratios intermediate of air and air-saturated water. However, 40Ar/36Ar is not correlated with either 84Kr/36Ar or 130Xe/36Ar, and the fluid inclusion 36Ar concentrations of 0.2-3.5 × 10-10 mol/g (calculated from measured Cl/36Ar and thermometric salinity measurements) extend below the seawater value of 0.34 × 10-10 mol/g, suggesting that contamination with modern air is a minor artifact. The range of fluid inclusion Br/Cl and I/Cl ratios overlap those previously documented for the mantle and magmatic-hydrothermal ore deposits, and the fluids' unusually low 36Ar concentration is consistent with the involvement of magmatic-hydrothermal fluids. Input of additional non-magmatic fluid components is suggested by the spread in Br/Cl and I/Cl to values characteristic of bittern brine sedimentary formation waters and near atmospheric 40Ar/36Ar. These data are compatible with mixing of magmatic-hydrothermal fluids and evaporated seawater, which was modified by interaction with back-arc basin sediments as the major control on ore formation. Low Br/Cl (<0.5 × 10-3) and I/Cl (<5.0 × 10-6) values that would provide evidence for evaporite dissolution as an important source of fluid salinity were not detected.

Marschik, Robert; Kendrick, Mark A.

2015-03-01

321

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

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

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

2012-09-01

322

75 FR 20625 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013, 2014

...INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-149 (Third Review)] Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject...

2010-04-20

323

Sol-gel synthesis of barium titanate powders using barium acetate and titanium(IV) isopropoxide  

SciTech Connect

A sol-gel process for low-temperature preparation of BaTiO{sub 3} powders is described. Chemical polymerization between barium acetate and titanium(IV) isopropoxide leads to the formation of barium titanate gels. After suitable drying and calcination treatments, the barium titanate gels were converted to BaTiO{sub 3} powders. The barium titanate gels and powders were characterized by TGA, DTA, and XRD. The results of these analyses indicate that it is possible to obtain stoichiometric (Ba/Ti = 0.99), homogeneous, high-purity BaTiO{sub 3} powders using relatively inexpensive barium acetate as a starting material.

Phule, P.P.; Risbud, S.H. (Univ. of Arizona, Tucson (USA))

1988-03-01

324

Preparation of magnetic nano-composite: barium hexaferrite loaded in the ordered meso-porous silica matrix (MCM-41).  

PubMed

In this work a magnetic nano-composite was synthesized by modified incorporation of iron-barium complex into ordered meso-porous silica (MCM-41) as a matrix. The MCM-41 was synthesized by silylation treatment which was accompanied by pH adjusting. Low angle XRD patterns of both annealed MCM-41 and resulted composite exhibited the characteristic reflection of high quality hexagonal meso-structures. TEM image of the composite material revealed that the hexagonal ordered meso-structure host material was not affected by wet impregnation and subsequent calcination in order to incorporate with barium hexaferrite. Also, TEM images accompanied by EDS analysis confirmed the formation of second phase consists of barium and iron ions inside the MCM-41 channels. The resulted composite material showed a super-paramagnetic nature at room temperature. PMID:20355520

Emamian, H R; Honarbakhsh-Raouf, A; Ataie, A

2010-04-01

325

Distribution of lead between copper and matte and the activity of PbS in copper-saturated mattes  

Microsoft Academic Search

The distribution coefficients of lead between copper and matte phases have been measured at 1405 and 1505 K and correlated\\u000a with lead and iron concentrations in metallic copper and matte. Experiments covered the ranges of 0.009 to 1.8 and 0 to 11\\u000a wt pct lead and iron in matte, respectively. Distribution coefficients of lead between copper and iron-free matte, at

S. N. Sinha; H. Y. Sohn; M. Nagamori

1984-01-01

326

Noise characterisation of barium ferrite dispersions  

Microsoft Academic Search

Structural changes in barium ferrite dispersions during the milling process have been investigated by using noise measurements of the remanent states (DC modulation noise). Doped barium ferrite particles mixed with solvents, self wetting resins and binders were dispersed using a bead mill. Samples extracted at intervals during the process were coated onto PET film and magnetically oriented before drying. Tapes

S. M. McCann; P. M. Sollis; P. R. Bissell; T. Onions

1999-01-01

327

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...

328

Tribological properties of barium ferrite films  

Microsoft Academic Search

Acoustic emission and friction coefficients have been measured during start-stop and continuous sliding for pure and doped barium ferrite films, without lubrication, and compared with concomitant surface topography and magnetic properties. Barium ferrite films averaging about 100 nm in thickness, were produced on thermally oxidized Si substrates by sputter deposition and then furnace or rapid thermal annealed in order to

M. Scherge; X. Sui; X. Ma; C. L. Bauer; M. S. Jhon; M. H. Kryder

1995-01-01

329

Hydrothermal alteration, fluid inclusions and stable isotope systematics of the Alvo 118 iron oxide-copper-gold deposit, Carajás Mineral Province (Brazil): Implications for ore genesis  

NASA Astrophysics Data System (ADS)

The Alvo 118 iron oxide-copper-gold (IOCG) deposit (170 Mt at 1.0 wt.% Cu, 0.3 g/t Au) lies in the southern sector of the Itacaúnas Shear Belt, Carajás Mineral Province, along a WNW-ESE-striking, 60-km-long shear zone, close to the contact of the ~2.76-Ga metavolcano-sedimentary Itacaiúnas Supergroup and the basement (~3.0 Ga Xingu Complex). The Alvo 118 deposit is hosted by mafic and felsic metavolcanic rocks and crosscutting granitoid and gabbro intrusions that have been subjected to the following hydrothermal alteration sequence towards the ore zones: (1) poorly developed sodic alteration (albite and scapolite); (2) potassic alteration (biotite or K-feldspar) accompanied by magnetite formation and silicification; (3) widespread, pervasive chlorite alteration spatially associated with quartz-carbonate-sulphide infill ore breccia and vein stockworks; and (4) local post-ore quartz-sericite alteration. The ore assemblage is dominated by chalcopyrite (~60%), bornite (~10%), hematite (~20%), magnetite (10%) and subordinate chalcocite, native gold, Au-Ag tellurides, galena, cassiterite, F-rich apatite, xenotime, monazite, britholite-(Y) and a gadolinite-group mineral. Fluid inclusion studies in quartz point to a fluid regime composed of two distinct fluid types that may have probably coexisted within the timeframe of the Cu-Au mineralizing episode: a hot (>200°C) saline (32.8‰ to 40.6 wt.% NaCl eq.) solution, represented by salt-bearing aqueous inclusions, and a lower temperature (<200°C), low to intermediate salinity (<15 wt.% NaCl eq.) aqueous fluid defined by two-phase (LH2O + VH2O) fluid inclusions. This trend is very similar to those defined for other IOCG systems of the Carajás Mineral Province. ? 18OH2O values in equilibrium with calcite (-1.0‰ to 7.5‰ at 277°C to 344°C) overlap the lower range for primary magmatic waters, but the more 18O-depleted values also point to the involvement of externally derived fluids, possibly of meteoric origin. Furthermore, sulphide ? 34S values (5.1‰ to 6.3‰), together with available boron isotope and Cl/Br-Na/Cl data provide evidence for a significant component of residual evaporative fluids (e.g., bittern fluids generated by seawater evaporation) in this scenario that, together with magma-derived brines, would be the main sources of the highly saline fluids involved in the formation Alvo 118 IOCG deposit. The restricted high temperature sodic alteration, the pervasive overprinting of the potassic alteration minerals by chlorite proximal to the ore zones, ore breccias with open-space filling textures in brittle structures, microthermometric and stable isotope data indicate, collectively, that the Alvo 118 IOCG system developed at structurally high levels and may be considered the shallower representative of the IOCG systems of the CMP.

Torresi, Ignacio; Xavier, Roberto Perez; Bortholoto, Diego F. A.; Monteiro, Lena V. S.

2012-03-01

330

Communications to the Editor Synthesis of Monodisperse Nanoparticles of Barium  

E-print Network

Communications to the Editor Synthesis of Monodisperse Nanoparticles of Barium Titanate: Toward of barium titanate, BaTiO3, with diameters ranging from 6 to 12 nm. Barium titanate is a room,10 In the synthesis developed here, barium titanium ethyl hexano-isopropoxide (A

331

Method for harvesting rare earth barium copper oxide single crystals  

DOEpatents

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.

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

1996-04-02

332

Method for harvesting rare earth barium copper oxide single crystals  

DOEpatents

A method of preparing high temperature superconductor single crystals. 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.

Todt, Volker R. (Lemont, IL); Sengupta, Suvankar (Columbus, OH); Shi, Donglu (Cincinnati, OH)

1996-01-01

333

Correlation Between Whisker Initiation and Compressive Stress in Electrodeposited Tin–Copper Coating on Copper Leadframes  

Microsoft Academic Search

To evaluate the contribution of coating stress to whisker initiation from IC package leads, the stress distribution in the coating was investigated by finite-element analysis (FEA). Two different leadframe samples, which were composed of the same tin-copper coating on two different copper-leadframe materials, namely, copper-iron (hereafter, CUFE; corresponding to CDA number C19400) and copper-chromium (CUCR; CDA number C18045), were used

Takahiko Kato; Haruo Akahoshi; Masato Nakamura; Takeshi Terasaki; Tomio Iwasaki; Tomoaki Hashimoto; Asao Nishimura

2010-01-01

334

Magnetic and dielectric properties of barium titanate-coated barium ferrite  

Microsoft Academic Search

Flaky barium ferrite with hexagonal molecular structure was successfully prepared by reverse microemulsion method, and was coated with barium titanate through a coordination–precipitation technique. The prepared composite particles were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), vibrating sample magnetometry (VSM) and vector network analyzer. Barium ferrite nanoparticles are proved to be single magnetic

Chao Wang; Xijiang Han; Ping Xu; Xiaohong Wang; Xueai Li; Hongtao Zhao

2009-01-01

335

Barium ions for quantum computation  

NASA Astrophysics Data System (ADS)

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.

Dietrich, Matthew

336

Abundance Analysis of Barium Stars  

E-print Network

We obtain the chemical abundances of six barium stars and two CH subgiant stars based on the high signal-to-noise ratio and high resolution Echelle spectra. The neutron capture process elements Y, Zr, Ba, La, Eu show obvious overabundance relative to the Sun, for example, their [Ba/Fe] values are from 0.45 to 1.27. Other elements, including Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Ni, show comparable abundances to the Solar ones, and their [Fe/H] cover a range from $-$0.40 to 0.21, which means they belong to Galactic disk. The predicts of the theoretical model of wind accretion for binary systems can explain the observed abundance patterns of the neutron capture process elements in these stars, which means that their overabundant heavy-elements could be caused by accreting the ejecta of AGB stars, the progenitors of the present white dwarf companions in the binary systems.

G. Q. Liu; Y. C. Liang; L. Deng

2008-11-13

337

Barium Isotopes in Single Presolar Grains  

NASA Technical Reports Server (NTRS)

Barium isotopic compositions of single presolar grains were measured by laser ablation laser resonant ionization mass spectrometry and the implications of the data for stellar processes are discussed. Additional information is contained in the original extended abstract.

Pellin, M. J.; Davis, A. M.; Savina, M. R.; Kashiv, Y.; Clayton, R. N.; Lewis, R. S.; Amari, S.

2001-01-01

338

Point defects and properties of barium titanate  

SciTech Connect

The authors consider the simple case of uniformly distributed atomic point defects over the volume of a barium titanate crystal. The diversity of phenomena associated with the transport of electric charge in barium titanate is determined by the distinctive features of its point defects: the existence of two regions of disorder, one of which corresponds to a compensated semiconductor while the other corresponds to an uncompensated semiconductor and a difference in the kinetics of the relaxation of two types of dominant atomic defects, viz., oxygen and barium vacancies. The authors have made a quantitative examination of the interrelation between the conditions of the preparation of materials based on barium titanate and their electrical conductivity.

Prisedskii, V.V.; Tret'yakov, Y.D.

1986-01-01

339

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

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

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

2015-03-01

340

Impact of vanadium ions in barium borate glass  

NASA Astrophysics Data System (ADS)

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.

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

2015-02-01

341

Spinwave spectrum for barium ferrite (abstract)  

Microsoft Academic Search

In order to determine whether barium ferrite will be suitable for microwave and millimeter wave device applications, it is essential to calculate the intrinsic ferrimagnetic resonance linewidth for perfect single crystals of this compound. The two mechanisms believed to be responsible for the intrinsic linewidth of barium ferrite, the Kasuya–LeCraw1 two-magnon one-phonon process and the two-magnon scattering caused by the

S. P. Marshall; J. B. Sokoloff

1990-01-01

342

Fabrication of Barium Ferrite Thick Films  

Microsoft Academic Search

During recent years the need for high quality self-biased barium ferrite (BaFe12O19) thick films had been increasing due to its chemical stability, anisotropy and oriented hexagonal M-type ferrites. Our goal is to fabricate barium ferrite thick films to be incorporated in self-biased microwave devises. Different methods such as sputtering, pulse laser deposition, CVD and modified liquid phase deposition have been

Wei Jiang Yeh; Carla Blengeri-Oyarce; Sundeep Pillamari; Jnana Manoj Appikonda; Laura Diaz; Yanko Kranov; David McIlroy

2008-01-01

343

Dielectric and Piezoelectric Properties of Barium Titanate  

Microsoft Academic Search

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

Shepard Roberts

1947-01-01

344

Copper and zinc recycling from copper alloys` spent pickling solutions  

SciTech Connect

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.

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

1995-12-31

345

Effect of additions of praseodymium and bismuth oxides on the properties of barium hexaferrites  

SciTech Connect

Among oxide permanent magnets, of greatest practical interest are those made of barium hexaferrite. Because of its high constant of uniaxial anisotropy, a barium ferrite can be employed for producing permanent magnets of large coercive force. The formation of important technical properties in barium ferrites is strongly affected by their production technology, in particular, the addition of oxides, such as those or bismuth and some rare-earth elements. The goal of this work was to study the effect of bismuth and praseodymium on the parameters of the static hysteresis loop, magnetic microstructure, and electronic configuration of iron ions in the BaO.nFe/sub 2/O/sub 3/ (5.0 less than or equal tonless than or equal to6.0) system. It is determined that the changes induced in the crystallostructural parameters, magnetic microstructure, and electronic spectrum of a barium ferrite by the addition of praseodymium and bismuth oxides to the ferrite powder charge control to a large extent the formation of the magnetic energy level.

Kirichok, P.P.; Garmash, V.Y.; Verezhak, O.F.; Voronina, N.B.

1985-08-01

346

Recovery of scrap iron metal value using biogenerated ferric iron.  

PubMed

The utility of employing biogenerated ferric iron as an oxidant for the recycling of scrap metal has been demonstrated using continuously growing cells of the extremophilic organism Acidithiobacillus ferrooxidans. A ferric iron rich (70 mol%) lixiviant resulting from bioreactor based growth of A. ferrooxidans readily solubilized target scrap metal with the resultant generation of a leachate containing elevated ferrous iron levels and solubilized copper previously resident in the scrap metal. Recovery of the copper value was easily accomplished via a cementation reaction and the clarified leachate containing a replenished level of ferrous iron as growth substrate was shown to support the growth of A. ferrooxidans and be fully recyclable. The described process for scrap metal recycling and copper recovery was shown to be efficient and economically attractive. Additionally, the utility of employing the E(h) of the growth medium as a means for monitoring fluctuations in cell density in cultures of A. ferrooxidans is demonstrated. PMID:16440341

Ballor, Nicholas R; Nesbitt, Carl C; Lueking, Donald R

2006-04-20

347

Copper Sulfide Precipitation by Yeasts from Acid Mine-Waters  

PubMed Central

Two strains of Rhodotorula and one of Trichosporon precipitated dissolved copper with H2S formed by reducing elemental sulfur with glucose. Iron stimulated this activity under certain conditions. In the case of Rhodotorula strain L, iron stimulated copper precipitation aerobically at a copper concentration of 18 but not 180 ?g/ml. Anaerobically, the L strain required iron for precipitation of copper from a medium with 180 ?g of copper per ml. Rhodotorula strain L was able to precipitate about five times as much copper anaerobically as aerobically. The precipitated copper was identified as copper sulfide, but its exact composition could not be ascertained. Iron was not precipitated by the H2S formed by any of the yeasts. Added as ferric iron, it was able to redissolve copper sulfide formed aerobically by Rhodotorula strain L from 18 but not 180 ?g of copper per ml of medium. Since the yeasts were derived from acid mine-waters, their ability to precipitate copper may be of geomicrobial importance. PMID:16349711

Ehrlich, H. L.; Fox, Sally I.

1967-01-01

348

The ubiquity of iron.  

PubMed

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

Frey, Perry A; Reed, George H

2012-09-21

349

Thermochemical hydrogen production via a cycle using barium and sulfur - Reaction between barium sulfide and water  

NASA Technical Reports Server (NTRS)

The reaction between barium sulfide and water, a reaction found in several sulfur based thermochemical cycles, was investigated kinetically at 653-866 C. Gaseous products were hydrogen and hydrogen sulfide. The rate determining step for hydrogen formation was a surface reaction between barium sulfide and water. An expression was derived for the rate of hydrogen formation.

Ota, K.; Conger, W. L.

1977-01-01

350

Release of aluminum, arsenic, cadmium, chromium, copper, iron, lead, and zinc in a coal leachate, and their removal from solution undergoing neutralization  

Microsoft Academic Search

Whole coal contains significant amounts of iron pyrite which is oxidized ultimately to ferric acid sulfate. As a result, trace elements are released from the coal and other minerals in potentially hazardous concentrations. The purpose of this research was to: (1) study the release and mobility of selected trace elements during the weathering of coal; (2) seek to understand factors

Tatum

1992-01-01

351

Entrainment behavior of copper and copper matte in copper smelting operations  

NASA Astrophysics Data System (ADS)

In copper smelting, the loss of copper to the slag due to entrainment is largely influenced by the flotation of copper metal and/or matte in the slag phase. To evaluate this behavior, the surface tension of copper as a function of temperature and oxygen pressure and the interfacial tension of the copper-iron matte-slag system as a function of matte grade were measured. From the surface and interfacial tension values, the spreading and flotation coefficients of the copper, matte, and slag system were calculated. Ternary interfacial energy diagrams were also con-structed using these data. It is shown that matte droplets containing higher than 32 mass pct Cu will not form a film on rising gas bubbles when they collide in the slag phase. However, matte droplets will attach to gas bubbles upon collision and thus can be floated over the entire range of matte composition. Spreading of copper on bubbles is not possible at oxygen pressures between 10-12 and 10-8 atm. Flotation of copper by gas bubble in slag is possible at oxygen pressure higher than 10-9 atm. However, it is feasible for rising matte droplets (attached to rising bubble) to trap and float copper irrespective of the matte grade.

Ip, S. W.; Toguri, J. M.

1992-06-01

352

Temperature-dependent coherent oscillation in photorefractive relaxor strontium barium  

E-print Network

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

Osnabrück, Universität

353

Two barium stars in the Galactic bulge  

E-print Network

Barium stars conserve important information on the s-process and the third dredge-up in intermediate mass stars. Their discovery in various environments is therefore of great help to test nucleosynthesis and mixing models. Our aim is to analyse two stars with a very strong barium line detected in a large survey of red giants in the Galactic bulge. Abundance analysis was done comparing synthetic model spectra based on the COMARCS code with our medium resolution spectra. Abundances of Ba, La, Y, and Fe were determined. Beside the two main targets, the analysis was also applied to two comparison stars. We confirm that both stars are barium stars. They are the first ones of this kind identified in the Galactic bulge. Their barium excesses are among the largest values found up to now. The elemental abundances are compared with current nucleosynthesis and mixing models. Furthermore, we estimate a frequency of barium stars in the Galactic bulge of about 1%, which is identical to the value for disc stars.

Lebzelter, Thomas; Straniero, Oscar; Aringer, Bernhard

2013-01-01

354

Iron and Iron Deficiency  

MedlinePLUS

... from these substances is usually not of concern. Vegetarian diets are low in heme iron, but careful meal ... heme iron sources in the diet (e.g., vegetarian diets) Low absorption Taking antacids beyond the recommended dose ...

355

Properties and uses of barium ferrite ceramic magnets  

Microsoft Academic Search

1.Barium ferrite is a promising ceramic material for permanent magnets. It does not include scarce and expensive materials. It has a low density and high coercive force; components with barium ferrite magnets therefore have high stability in operation, and high maximum specific magnetic energy, especially in anisotropic magnets.2.For the successful use of barium ferrite magnets it is essential to consider

I. Yu. Gershov

1963-01-01

356

Experiments with remote entanglement using single barium ions Nathan Kurz  

E-print Network

Experiments with remote entanglement using single barium ions Nathan Kurz A dissertation submitted entanglement using single barium ions Nathan Kurz Chair of the Supervisory Committee: Dr. Boris B. Blinov Physics Department Barium ion qubits are trapped and Doppler cooled in a linear Paul trap and the tasks

Blinov, Boris

357

Magnetoresistive Conductive Polyaniline-Barium Titanate Nanocomposites with Negative Permittivity  

E-print Network

Magnetoresistive Conductive Polyaniline-Barium Titanate Nanocomposites with Negative Permittivity field sensors,10 energy electrodes11 and biosensors.12,13 Barium titanate (BaTiO3) as transition metal Carolina 28301, United States ABSTRACT: Polyaniline (PANI) polymer nanocomposites (PNCs) filled with barium

Guo, John Zhanhu

358

Ferroelectric Properties of Individual Barium Titanate Nanowires Investigated  

E-print Network

Ferroelectric Properties of Individual Barium Titanate Nanowires Investigated by Scanned Probe on the ferroelectric properties of individual single-crystalline barium titanate nanowires. We show that nonvolatile report the scanned probe characterization of individual single-crystalline barium titanate (BaTiO3) nano

Heller, Eric

359

PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE  

E-print Network

PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE G.MALOVICHKO, V of crystals from barium titanate (BT) family make them promising candidates for various applications@uos.de; vgrachev@uos.de; schirmer@uos.de Abstract The results of the study of charge transfer processes in barium

Malovichko, Galina

360

Compact pulse forming line using barium titanate ceramic material  

Microsoft Academic Search

Ceramic material has very high relative permittivity, so compact pulse forming line can be made using these materials. Barium titanate (BaTiO3) has a relative permittivity of 1200 so it is used for making compact pulse forming line (PFL). Barium titanate also has piezoelectric effects so it cracks during high voltages discharges due to stresses developed in it. Barium titanate is

Surender Kumar Sharma; P. Deb; R. Shukla; T. Prabaharan; A. Shyam

2011-01-01

361

Surface treatment of barium gallogermanate laser glass  

NASA Astrophysics Data System (ADS)

The surface of barium gallogermanate glass is modified through HCl solution etching to remove the surface defects and contaminations. The etching process and mechanism for barium gallogermanate glass in hydrochloric acid are investigated, and its optimum conditions are determined. However, the HCl etching induces the insoluble etch product containing minute crystal particles on glass surface. By heating BGG glass at the optical fiber drawing temperature, the deposited surface layer turned to be amorphous again and results in the increase of the transmittance of glass. The results indicated that the HCl etching combined with subsequent high-temperature heat treatment is an effective approach to improve the surface quality of barium gallogermanate glass, which would reduce the optical loss of the final optical fiber.

Yang, Gang; Qian, Qi; Yang, Zhongmin

2011-01-01

362

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

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

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

2013-01-01

363

Effect of a deficiency of ceruloplasmin copper in blood plasma on copper metabolism in the brain.  

PubMed

Copper deficiency in adult rats was induced by addition of silver chloride to the feed. The concentrations of silver, copper, iron, and zinc and relative activity of genes for copper transporting proteins and copper enzymes were measured in the cortex, cerebellum, hippocampus, amygdala, pituitary gland, and hypothalamus. Silver was accumulated only in the hypothalamic-pituitary system. These changes were accompanied by a decrease in the concentration of copper and increase in the contents of iron and zinc. Activity of genes for copper transport enzymes (high-affinity copper transporter; and two copper transport ATPases, ATP7A and ATP7B) and copper enzymes that were formed in the intracellular secretory pathway did not decrease in the brain of rats with copper deficiency. Relative activity of genes for intracellular copper enzymes (Cu(2+)/Zn(2+) superoxide dismutase and subunit IV of cytochrome c oxidase), concentration of immunoreactive polypeptides of superoxide dismutase, and enzymatic activity of superoxide dismutase remained unchanged under these conditions. PMID:20396748

Babich, P S; Tsymbalenko, N V; Klotchenko, S A; Platonova, N A; Masalova, O O; Zatulovski, E A; Shavlovskii, M M; Sapronov, N S; Puchkova, L V

2009-10-01

364

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)

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.

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

365

Intracytoplasmic barium salts in pleural fluid.  

PubMed

Cytological examination of the pleural effusion fluid obtained from a 66-yr-old Chinese lady showed numerous intra- and extracytoplasmic colourless refractile non-birefringent crystals. X-ray analysis of the crystals identified barium salts. On further inquiry, it was learnt that the fluid obtained had been placed in a specimen bottle provided by the x-ray department. This container was presumably contaminated with barium salts. The case highlights an unusual aspect of specimen contamination and the usefulness of x-ray analysis in the identification of crystals/substances. PMID:8165010

Chan, A C; Collins, R J; Cheung, T K

1993-10-01

366

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

E-print Network

barium strontium titanate films on Nb-doped strontium titanate substrates were capped with an unbondedElectric field tunable 60 GHz ferromagnetic resonance response in barium ferrite-barium strontium titanate multiferroic heterostructures Young-Yeal Song,1,a Jaydip Das,1 Pavol Krivosik,1,2 Nan Mo,1

Patton, Carl

367

Barium Titanate and Bismuth Oxide Nanocomposites Barium titanate, BaTiO3, and bismuth oxide Bi2O3 are transparent materials with  

E-print Network

Barium Titanate and Bismuth Oxide Nanocomposites Barium titanate, BaTiO3, and bismuth oxide Bi2O3 Wall in Tetragonal Barium Titanate", H. Chaib, F. Schlaphof, T. Otto and L. M. Eng, Journal of Physics

Harmon, Julie P.

368

Method for preparing hydrous iron oxide gels and spherules  

DOEpatents

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.

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

2003-07-29

369

Selective preconcentration/separation of copper(II), iron(III), and lead(II) as their N'-benzoyl-N,N-diisobutylthiourea chelates on Amberlite XAD-16 resin.  

PubMed

A preconcentration/separation procedure for copper(II), iron(III), and lead(II) ions has been established for use prior to their flame atomic absorption spectrometric determination. The presented procedure is based on adsorption of analyte ions on Amberlite XAD-16 resin as their N'-benzoyl-N,N-diisobutylthiourea chelates. The influence of analytical parameters including pH of the solutions and type of eluent on the recoveries of Cu(II), Fe(III), and Pb(II) ions was investigated. The recoveries of the analytes were generally > 95%. No interference effects were observed from alkaline, earth alkaline, or transition metals on the recoveries of the studied metals. The LODs based on 3sigma were 1.9 microg/L for Cu, 5.9 microg/L for Fe, and 3.1 microg/L for Pb. Validation of the procedure was carried out by analyzing standard reference material 1568a (rice flour). The procedure was applied to the determination of analytes in natural water samples. PMID:20480920

Soylak, Mustafa; Kariper, I Afsin

2010-01-01

370

Electric Tuning of Ferromagnetic Resonances in Hexagonal-Barium-Ferrite\\/Barium-Strontium-Titanate Heterostructures  

Microsoft Academic Search

This letter reports the first demonstration of a monolithic heterostructure with a large electric tuning of the ferromagnetic resonance (FMR) at millimeter-wave frequencies. The structure is composed of a barium-strontium-titanate (BST) film and two thin platinum electrodes, all grown on a barium ferrite slab with in-plane uniaxial anisotropy. The electric tuning of the FMR responses around 60 GHz was obtained

Young-Yeal Song; Jaydip Das; Pavol Krivosik; Hyung-Kee Seo; Mingzhong Wu

2010-01-01

371

Nonlinear electric field tuning characteristics of yttrium iron garnetlead zirconate titanate microwave resonators  

E-print Network

crystals of barium ferrite that have high uniaxial magnetic anisotropy. Lead zirconium titanate PZT or leadNonlinear electric field tuning characteristics of yttrium iron garnet­lead zirconate titanate in a bilayer of yttrium iron garnet YIG -lead zirconate titanate PZT . The tuning is facilitated

Srinivasan, Gopalan

372

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

SciTech Connect

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.

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

373

Copper hypersensitivity.  

PubMed

The world production of copper is steadily increasing. Although humans are widely exposed to copper-containing items on the skin and mucosa, allergic reactions to copper are only infrequently reported. To review the chemistry, biology and accessible data to clarify the implications of copper hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common. As a metal, it possesses many of the same qualities as nickel, which is a known strong sensitizer. Cumulative data on subjects with presumed related symptoms and/or suspected exposure showed that a weighted average of 3.8% had a positive patch test reaction to copper. We conclude that copper is a very weak sensitizer as compared with other metal compounds. However, in a few and selected cases, copper can result in clinically relevant allergic reactions. PMID:25098945

Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

2014-10-01

374

Investigations on barium ferrite magnetic thin films  

Microsoft Academic Search

Summary form only given. Barium ferrite thin films are promising candidates for both longitudinal and perpendicular recording media. It is important to understand the time dependent phenomena in these thin films as many of the critical properties of magnetic recording media are directly related to it. The time dependent phenomenon is also known as magnetic viscosity. The magnetic viscosity parameter,

Wenjie Pang; Hong Sun

2002-01-01

375

STABILIZED BARIUM TITANATE CERAMICS FOR CAPACITOR DIELECTRICS  

Microsoft Academic Search

The effects of additions of LaâOâ and LaâOâ--; 3TiOâ on the electronic properties of barium titanate were investigated. ; It was found that small additions of the components markedly increase the ; lifetime of the material subjected to d-c fields of 50 v per mil at 200 l ; C. (auth);

J. B. MacChesney; P. K. Gallagher; F. V. DiMarcello

1963-01-01

376

Phase associations of barium in marine sediments  

Microsoft Academic Search

Barium (Ba) is associated with various phases in marine sediments, including carbonates, organic matter, opal, ferromanganese oxyhydroxides, terrestrial silicates and other detrital material, and barite. Using samples representing sediments from a wide variety of sedimentary environments and export production regimes, we show that there is a considerable range in Ba concentrations associated with five operationally defined phases using a sequential

Meagan Eagle Gonneea; Adina Paytan

2006-01-01

377

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

PubMed

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

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

2011-01-01

378

Dispersion strengthened copper  

DOEpatents

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.

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

1989-01-01

379

Dispersion strengthened copper  

DOEpatents

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.

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

1990-01-01

380

Dispersion strengthened copper  

SciTech Connect

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.

Sheinberg, H.; Meek, T.T.; Blake, R.D.

1988-12-05

381

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

SciTech Connect

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.

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

2013-01-01

382

Occupational Exposure to Welding Fume among Welders: Alterations of Manganese, Iron, Zinc, Copper, and Lead in Body Fluids and the Oxidative Stress Status  

PubMed Central

Welders in this study were selected from a vehicle manufacturer; control subjects were from a nearby food factory. Airborne manganese levels in the breathing zones of welders and controls were 1.45 ± SD1.08 mg/m3 and 0.11 ± 0.07 ?g/m3, respectively. Serum levels of manganese and iron in welders were 4.3-fold and 1.9-fold, respectively, higher than those of controls. Blood lead concentrations in welders increased 2.5-fold, whereas serum zinc levels decreased 1.2-fold, in comparison with controls. Linear regression revealed the lack of associations between blood levels of five metals and welder’s age. Furthermore, welders had erythrocytic superoxide dismutase activity and serum malondialdehyde levels 24% less and 78% higher, respectively, than those of controls. These findings suggest that occupational exposure to welding fumes among welders disturbs the homeostasis of trace elements in systemic circulation and induces oxidative stress. PMID:15091287

Li, Guojun Jane; Zhang, Long-Lian; Lu, Ling; Wu, Ping; Zheng, Wei

2014-01-01

383

Trapped Barium Ions for Quantum ComputationTrapped Barium Ions for Quantum Computation V.Mirgon, G.Shu, A.Avril, M.Dietrich N.Kurz, E. Shahar, and B.B.Blinov  

E-print Network

Trapped Barium Ions for Quantum ComputationTrapped Barium Ions for Quantum Computation V.Mirgon, G of Washington Seattle WA 98195 Trapped Barium Ions for Quantum ComputationTrapped Barium Ions for Quantum

Blinov, Boris

384

Ultrafast laser inscription of bistable and reversible waveguides in strontium barium niobate crystals  

E-print Network

Ultrafast laser inscription of bistable and reversible waveguides in strontium barium niobate optical channel waveguides in strontium barium niobate nonlinear ferroelectric crystals by direct barium niobate SBN crystal because of its prime importance in modern photonics due to its nonlinear

385

Enhanced dielectric properties from barium strontium titanate films with strontium titanate buffer layers  

E-print Network

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- tive amounts of Ba and Sr. TC for pure barium t

Alpay, S. Pamir

386

Engineering domain configurations for enhanced piezoelectricity in barium titanate single crystals  

E-print Network

Engineering domain configurations for enhanced piezoelectricity in barium titanate single crystals piezoelectric responses of barium titanate single crystals under different crystallographic orientations, and use it to explain the ultrahigh piezoelectric response recently observed in a 270 cut barium titanate

Li, Jiangyu

387

Occupational genotoxicity among copper smelters.  

PubMed

Occupational exposure in a copper smelting industry may produce various adverse health effects including cancer. Despite a number of well-documented studies reporting an increased risk of cancer among copper smelter workers, the data on genotoxic effects in this industry are scarce. In view of the above, an assessment of DNA damage in peripheral blood leukocytes by Comet assay from copper smelter workers was undertaken. Additionally, the proton-induced X-ray emission (PIXE) analysis was assessed to determine the metal content of samples. The study was conducted with all workers from a copper smelter (males; n = 11), and a control group (n = 11) was recruited. The results of our study showed a significant increase (p < 0.001; Mann-Whitney test) in DNA damage in peripheral blood lymphocytes of smelter workers, compared to the controls (p < 0.001; Mann-Whitney test). No correlation between DNA damage or metal concentration and age mean or time of exposure was found under study. Our findings indicate that copper smelter workers have increased levels of DNA damage in somatic cells, suggesting a potential health risk for the workers. PIXE results show the presence of copper, iron, and other metals. PMID:22042770

De Olivera, Juliana Viégas Duarte; Boufleur, Liana Appel; Dos Santos, Carla Eliete Iochims; Dias, Johnny Ferraz; Squeff, Cíntia Haag; Silva, Guilherme Ruivo Gonçalves; Ianistcki, Martus; Benvegnú, Vinícius Cosmos; Da Silva, Juliana

2012-10-01

388

Band-Spectrum of Barium Oxide  

Microsoft Academic Search

THE introduction of barium salts to flames or arcs leads, in presence of oxygen, to the production of a characteristic band-spectrum attributed to BaO. Mecke and Guillery1 derived a band-head equation. Mahanti2 gave a new vibrational analysis and also made a rotational analysis. From this the spectrum was shown to arise from a 1Sigma - 1Sigma transition with B'e =

Albin Lagerqvist; Erland Lind; R. F. Barrow

1949-01-01

389

Barium ferrite films grown by laser ablation  

Microsoft Academic Search

Pulsed laser ablation (PLA) has been used to grow barium ferrite films on Al2O3 single crystal substrates. When deposition occurs in an oxidising atmosphere at high temperatures, the films are single BaFe12O19 phase, very well oriented with (001) texture, and exhibit a large perpendicular magnetic anisotropy. In this case, the microstructure and the anisotropy orientation are not influenced by variation

A. Lisfia; J. C. Lodder; P. de Haan; M. A. Smithers; F. J. G. Roesthuis

1998-01-01

390

New barium ferrite particles: Spherical shape  

Microsoft Academic Search

Pure and ZnTi-doped spherical barium ferrite particles were prepared using two different methods: semicoprecipitation and ultrasonic spray pyrolysis. The ultrasonic spray pyrolysis method was more effective in controlling particle shape. Particle size was in between 0.27 and 0.3 ?m. Coercivity and saturation magnetization were in the range of 1000 to 5000 Oe and 49 to 53 emu\\/g, respectively. Crystallization of

Y. K. Hong; H. S. Jung

1999-01-01

391

Barium ferrite thin-film recording media  

Microsoft Academic Search

Both longitudinal and perpendicular barium ferrite thin films are being pursued as overcoatless magnetic recording media. In this paper, prior research on thin-film Ba ferrite is reviewed and the most recent results are presented. Self-textured high-coercivity longitudinal Ba ferrite thin films have been achieved using conventional rf diode sputtering. Microstructural studies show that c-axis in-plane oriented grains have a characteristic

Xiaoyu Sui; Matthias Scherge; Mark H. Kryder; John E. Snyder; Vincent G. Harris; Norman C. Koon

1996-01-01

392

New barium ferrite particles: Spherical shape  

Microsoft Academic Search

Pure and ZnTi-doped spherical barium ferrite particles were prepared using two different methods: semicoprecipitation and ultrasonic spray pyrolysis. The ultrasonic spray pyrolysis method was more effective in controlling particle shape. Particle size was in between 0.27 and 0.3 mum. Coercivity and saturation magnetization were in the range of 1000 to 5000 Oe and 49 to 53 emu\\/g, respectively. Crystallization of

Y. K. Hong; H. S. Jung

1999-01-01

393

Production of translationally cold barium monohalide ions  

E-print Network

We have produced sympathetically cooled barium monohalide ions BaX$^+$ (X = F, Cl, Br) by reacting trapped, laser cooled Ba$^+$ ions with room temperature gas phase neutral halogen-containing molecules. Reaction rates for two of these (SF$_6$ and CH$_3$Cl) have been measured and are in agreement with classical models. BaX$^+$ ions are promising candidates for cooling to the rovibrational ground state, and our method presents a straightforward way to produce these polar molecular ions.

DePalatis, M V

2013-01-01

394

Improving the magnetic properties of hydrothermally synthesized barium ferrite  

Microsoft Academic Search

The formation of fine barium ferrite (BaFe12O19) powders under hydrothermal conditions at [OH?]\\/[NO3?] ratio of 2 has been examined by employing barium nitrate and ferric nitrate as the starting materials. The effects of Ba\\/Fe ratio, reaction temperature and time on the formation, particle size, and magnetic properties of barium ferrite were studied. To further enhance the magnetic properties of hydrothermally

Xiangyuan Liu; John Wang; Leong-Ming Gan; Ser-Choon Ng

1999-01-01

395

An investigation of particle size effects in ultrafine barium ferrite  

Microsoft Academic Search

Ultrafine particles of barium ferrite in the size range 5-100 nm have been synthesized by thermal decomposition of a citrate precursor. The precursor decomposed at 425°C is amorphous, but crystalline barium ferrite starts forming at temperatures of 550°C and above. Barium ferrite which shows a monophase X-ray diffraction pattern and well-resolved Mössbauer spectra is obtained at 700°C. The Mössbauer spectra

V. K. Sankaranarayanan; Q. A. Pankhurst; D. P. E. Dickson; C. E. Johnson

1993-01-01

396

Remanence, self-demagnetization and their ramifications for magnetic modelling of iron oxide copper-gold deposits: An example from Candelaria, Chile  

NASA Astrophysics Data System (ADS)

Magnetic modelling can be a powerful tool for understanding the architecture of numerous types of mineralized systems; e.g., iron ore, IOCG and porphyry deposits. In such modelling, the induced component is generally assumed to be dominant, whereas remanent magnetization is often neglected and, furthermore, the effects of self-demagnetization are commonly ignored. We present rock property measurements (magnetic susceptibility and remanent magnetization) from the Candelaria IOCG deposit in northern Chile. The results demonstrate that remanence is relatively weak (< 20% of induced) and that the causative lithologies have very high magnetic susceptibilities (3-4 SI), which makes them highly prone to self-demagnetization. The rock property results were used to constrain a simplified forward model in which the causative bodies are modelled as a series of sub-horizontal highly magnetic sheets, corresponding to “mantos”. These “mantos” occur north and south of Candelaria, sub-perpendicular to a splay off the Atacama Fault Zone. We demonstrate that Candelaria's unusual magnetic anomaly is due to a combination of its highly magnetic sub-horizontal architecture, and self-demagnetization effects. A further simplified model was used to calculate two synthetic anomalies, one ignoring and the other incorporating the self-demagnetization effect. These synthetic anomalies demonstrate that the magnetic anomaly amplitude is suppressed by up to approximately 50% at Candelaria due to self-demagnetization, and that the induced magnetization is also slightly rotated from the regional inducing field towards the plane of the “mantos”. The dominant paleomagnetic component recorded by the Candelaria deposit and host rocks is a normal polarity remanence of moderate to high stability which is interpreted to have been acquired during the mid-Cretaceous alteration and mineralisation event(s) that generated the magnetic minerals (predominantly magnetite). However, the presence of a reversed polarity overprint component in some samples suggests that the Candelaria deposit and its immediate environs have experienced a post 83 Ma thermal or thermochemical event that has not been previously recognised. The remanence directions of both polarities are rotated clockwise with respect to the expected directions for mid-Cretaceous/Early Tertiary fields, indicating clockwise rotation of the Candelaria area, including the adjacent batholith, through at least 45° since the acquisition of the normal and reversed remanence components, i.e. since 83 Ma. This case study illustrates the importance of understanding the magnetic behaviour of different ore types, and incorporating self-demagnetization into modelling procedures for highly magnetic targets in mineral exploration.

Austin, James; Geuna, Silvana; Clark, David; Hillan, Dean

2014-10-01

397

Barium hexaferrite suspensions for electrophoretic deposition.  

PubMed

In this investigation we have looked at the preparation of barium hexaferrite suspensions, with the stability of the magnetic barium hexaferrite particles being increased by the addition of a surfactant, dodecylbenzylsulfonic acid (DBSA). The influence of the solubility DBSA in different solvents and its adsorption onto the surfaces of particles with different sizes were determined from zeta-potential measurements. The most suitable and stable suspensions of barium hexaferrite particles, regardless of their sizes, were obtained in 1-butanol, and these were then used for a subsequent electrophoretic deposition. The microstructures of the deposits were examined with electron microscopy. The thickness and density of the deposits as a function of the electric field, the zeta-potential, the particle size, and the separation distance between the electrodes were investigated. The thickness of the deposits was found to increase with the increasing zeta-potential of the suspension and with the increasing separation distance between the electrodes. Denser deposits were obtained from the suspensions of smaller particles that had narrower particle size distributions. PMID:19541323

Ovtar, Simona; Lisjak, Darja; Drofenik, Miha

2009-09-15

398

Impact of vanadium ions in barium borate glass.  

PubMed

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. PMID:25194319

Abdelghany, A M; Hammad, Ahmed H

2015-02-25

399

High toughness-high strength iron alloy  

NASA Technical Reports Server (NTRS)

An iron alloy is provided which exhibits strength and toughness characteristics at cryogenic temperatures. The alloy consists essentially of about 10 to 16 percent by weight nickel, about 0.1 to 1.0 percent by weight aluminum, and 0 to about 3 percent by weight copper, with the balance being essentially iron. The iron alloy is produced by a process which includes cold rolling at room temperature and subsequent heat treatment.

Stephens, J. R.; Witzke, W. R. (inventors)

1980-01-01

400

Iron, transferrin and myelinogenesis  

NASA Astrophysics Data System (ADS)

Transferrin (Tf), the iron binding protein of vertebrates serum, is known to be synthesized by oligodendrocytes (Ols) in the central nervous system. It has been postulated that Tf is involved in Ols maturation and myelinogenesis. This link is particularly important in the understanding of a severe human pathology: the multiple sclerosis, which remains without efficient treatment. We generated transgenic mice containing the complete human Tf gene and extensive regulatory sequences from the 5 ' and 3 ' untranslated regions that specifically overexpress Tf in Ols. Brain cytoarchitecture of the transgenic mice appears to be normal in all brain regions examined, total myelin content is increased by 30% and motor coordination is significantly improved when compared with non-transgenic littermates. Tf role in the central nervous system may be related to its affinity for metallic cations. Normal and transgenic mice were used for determination of trace metals (iron, copper and zinc) and minerals (potassium and calcium) concentration in cerebellum and corpus callosum. The freeze-dried samples were prepared to allow proton-induced X-ray emission and Rutherford backscattering spectrometry analyses with the nuclear microprobe in Bordeaux. Preliminary results were obtained and carbon distribution was revealed as a very good analysis to distinguish precisely the white matter region. A comparison of metallic and mineral elements contents in brain between normal and transgenic mice shows that iron, copper and zinc levels remained constant. This result provides evidence that effects of Tf overexpression in the brain do not solely relate to iron transport.

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

2003-09-01

401

Creating unstable velocity-space distributions with barium injections  

NASA Technical Reports Server (NTRS)

Ion velocity-space distributions resulting from barium injections from orbiting spacecraft and shaped charges are discussed. Active experiments confirm that anomalous ionization processes may operate, but photoionization accounts for the production of the bulk of the barium ions. Pitch-angle diffusion and/or velocity-space diffusion may occur, but observations of barium ions moving upwards against gravity suggests that the ions retain a significant enough fraction of their initial perpendicular velocity to provide a mirror force. The barium ion plasmas should have a range of Alfven Mach numbers and plasma betas. Because the initial conditions can be predicted these active experiments should permit testing plasma instability hypotheses.

Pongratz, M. B.

1983-01-01

402

Pathogenic adaptations to host-derived antibacterial copper  

PubMed Central

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

Chaturvedi, Kaveri S.; Henderson, Jeffrey P.

2014-01-01

403

THE EFFECT OF ORTHO- AND POLYPHOSPHATE ON THE PROPERTIES OF IRON PARTICLES AND SUSPENSIONS  

EPA Science Inventory

Orthophosphate and polyphosphates are used widely by drinking water utilities to reduce lead, copper and iron release from distribution system materials, and reduce visible iron precipitation and related discolored-water complaints. Bench-scale experiments were conducted to evalu...

404

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

PubMed

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

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

2014-12-10

405

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

NASA Astrophysics Data System (ADS)

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 60 mol.%) reveals strong charge transfer UV absorption bands which are related to unavoidable trace iron impurities (Fe3+) 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 580 nm. 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.

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

2014-12-01

406

Trace elements in human physiology and pathology. Copper  

Microsoft Academic Search

Copper is a trace element, important for the function of many cellular enzymes. Copper ions can adopt distinct redox states oxidized Cu(II) or reduced (I), allowing the metal to play a pivotal role in cell physiology as a catalytic cofactor in the redox chemistry of enzymes, mitochondrial respiration, iron absorption, free radical scavenging and elastin cross-linking. If present in excess,

H. Tapiero; D. M. Townsend; K. D. Tew

2003-01-01

407

A Novel Copper A Containing Menaquinol NO Reductase from Bacillus azotoformans  

E-print Network

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

Schroeder, Imke

408

BARIUM IN TEETH AS INDICATOR OF BODY BURDEN  

EPA Science Inventory

A study was conducted to determine the biological availability of naturally occurring barium in a municipal drinking water by the analysis of barium in deciduous teeth of children. The grade school children of two Illinois towns were chosen for the study. The towns were chosen ba...

409

Laser Cooled Single Ion Spectroscopy of Magnesium and Barium  

Microsoft Academic Search

Individual ions of magnesium and barium have been isolated and confined in RF traps in an ultra high vacuum environment. The ion motion has been cooled by means of a resonant laser excitation. The single ions were detected by their laser induced fluorescence. The kinetic temperature of magnesium was measured to be less than 200 millidegrees Kelvin. In barium, a

Gary Robert Janik

1984-01-01

410

The application of barium ferrite particles in advanced recording media  

Microsoft Academic Search

Barium ferrite is a leading candidate material for advanced magnetic recording media. Tapes and disks made with it offer output amplitudes at recording densities of current interest (75-100 kfci) that far exceed those of advanced acicular oxides and are comparable to those of many commercially available media made with metallic particles (MP). The very high coercivity values available with barium

M. P. Sharrock; L. W. Carlson

1995-01-01

411

Recording performance of longitudinal barium ferrite thin film media  

Microsoft Academic Search

The high density recording characteristics of barium ferrite thin film media have been investigated. High levels of overwrite are achieved. Media microstructures have been identified to have a close relation to the noise behavior in the barium ferrite thin films. A linear increase in noise spectra is observed, indicating the existence of transition noise. In addition, positive ?M peaks are

Xiaoyu Sui; A. Singh; Yinglian Chen; D. N. Lambeth; M. K. Krydeer

1995-01-01

412

Thermal decomposition of (BaTi) citrates into barium titanate  

Microsoft Academic Search

From aqueous solutions of barium and titanium citrates two different (BaTi) citrate salts can be precipitated, depending on the pH of the solution. The ratio of barium to titanium in the salts is either 1 : 1 or 2 : 1. The thermal decomposition of the salts was investigated by means of DTA, TGA, infrared spectroscopy, and X-ray diffraction. At

D. Hennings; W. Mayr

1978-01-01

413

Explanation of the apparent sublinear photoconductivity of photorefractive barium titanate  

Microsoft Academic Search

We explain the apparent sublinear intensity dependence of photoconductivity in barium titanate. In our model shallow acceptors act as a reservoir for charges optically excited from the donors. As this reservoir fills, the fraction of occupied donors changes appreciably, changing the lifetime of the free carriers. We identify two types of barium titanate crystals having quite different photorefractive characteristics, depending

Daniel Mahgerefteh; Jack Feinberg

1990-01-01

414

Barium strontium titanate powder obtained by polymeric precursor method  

SciTech Connect

Pure barium strontium titanate powder, with Ba/Sr ratio of 80/20 was prepared by the polymeric precursor method (also called Pechini process). The powder was obtained after a calcination at 800 deg. C for 8 h and characterized by XRD, IR, BET and SEM. The requirements to avoid barium carbonate as a secondary phase are presented and discussed in detail.

Ries, A.; Simoes, A.Z.; Cilense, M.; Zaghete, M.A.; Varela, J.A

2003-03-15

415

Spatial and temporal zoning of hydrothermal alteration and mineralization in the Sossego iron oxide-copper-gold deposit, Caraja??s Mineral Province, Brazil: Paragenesis and stable isotope constraints  

USGS Publications Warehouse

The Sossego iron oxide-copper-gold deposit (245 Mt 1.1% Cu, 0.28 g/t Au) in the Caraja??s Mineral Province of Brazil consists of two major groups of orebodies (Pista-Sequeirinho-Baiano and Sossego-Curral) with distinct alteration assemblages that are separated from each other by a major high angle fault. The deposit is located along a regional WNW-ESE-striking shear zone that defines the contact between metavolcano-sedimentary units of the ???2.76 Ga Itacaiu??nas Supergroup and tonalitic to trondhjemitic gneisses and migmatites of the ???2.8 Ga Xingu Complex. The deposit is hosted by granite, granophyric granite, gabbro, and felsic metavolcanic rocks. The Pista-Sequeirinho-Baiano orebodies have undergone regional sodic (albite-hematite) alteration and later sodic-calcic (actinolite-rich) alteration associated with the formation of massive magnetite-(apatite) bodies. Both these alteration assemblages display ductile to ductile-brittle fabrics. They are cut by spatially restricted zones of potassic (biotite and potassium feldspar) alteration that grades outward to chlorite-rich assemblages. The Sossego-Curral orebodies contain weakly developed early albitic alteration and very poorly developed subsequent calcic-sodic alteration. These orebodies contain well-developed potassic alteration assemblages that were formed during brittle deformation that resulted in the formation of breccia bodies. Breccia matrix commonly displays coarse mineral infill suggestive of growth into open space. Sulfides in both groups of deposits were precipitated first with potassic alteration and more importantly with a later assemblage of calcite-quartz-epidote-chlorite. In the Sequeirinho orebodies, sulfides range from undeformed to deformed; sulfides in the Sossego-Curral orebodies are undeformed. Very late, weakly mineralized hydrolytic alteration is present in the Sossego/Currral orebodies. The sulfide assemblage is dominated by chalcopyrite with subsidiary siegenite, and millerite. Pyrrhotite and pyrite are minor constituents of ore in the Sequerinho orebodies while pyrite is relatively abundant in the Sossego-Curral bodies. Oxygen isotope partitioning between mineral pairs constrains temperatures in the deposit spatially and through time. In the Sequeirinho orebody, the early sodic-calcic alteration stage was characterized by temperatures exceeding 500??C and ??18OH2O values for the alteration fluid of 6.9 ?? 0.9???. Temperature declines outward and upward from the zone of most intense alteration. Paragenetically later copper-gold mineralization displays markedly lower temperatures (<300 ??C) and was characterized by the introduction of 18O-depleted hydrothermal fluids -1.8 ?? 3.4???. The calculated ??DH2O and ??18OH2O values suggest that the fluids that formed the early calcic-sodic alteration assemblage were of formational/metamorphic or magmatic origin. The decrease of ??18OH2O values through time may reflect influx of surficially derived waters during later alteration and mineralization events. Influx of such fluids could be related to episodic fluid overpressure, resulting in dilution and cooling of the metalliferous fluid, causing deposition of metals transported as metal chloride complexes. ?? Springer-Verlag 2007.

Monteiro, L.V.S.; Xavier, R.P.; Carvalho, E.R.; Hitzman, M.W.; Johnson, C.A.; Souza, Filho C.R.; Torresi, I.

2008-01-01

416

Accumulation and hyperaccumulation of copper in plants  

NASA Astrophysics Data System (ADS)

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.

Adam, V.; Trnkova, L.; Huska, D.; Babula, P.; Kizek, R.

2009-04-01

417

Barium Enhancement in NGC 6819 Blue Stragglers  

NASA Astrophysics Data System (ADS)

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.

Milliman, Katelyn; Mathieu, Robert D.; Schuler, Simon C.

2015-01-01

418

Proper Management for Morbid Iatrogenic Retroperitoneal Barium Insufflation  

PubMed Central

A barium enema is a diagnostic and therapeutic procedure commonly used for colon and rectum problems. Rectal perforation with extensive intra- and/or extraperitoneal spillage of barium is a devastating complication of a barium enema that leads to a significant increase in patient mortality. Due to the low number of reported cases in recent scientific literature and the lack of experience with the management of these cases, we would like to present our treatment approach to a rare case of retroperitoneal contamination with barium, followed by its intraperitoneal involvement during a diagnostic barium enema. Our experience with long-term management of the patient and the good outcome will be depicted in this paper. PMID:25580416

Vahedian-Ardakani, Jalal; Nazerani, Shahram; Saraee, Amir; Sarmast, Ali; Saraee, Ehsan

2014-01-01

419

Scattering lengths of calcium and barium isotopes  

SciTech Connect

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 {sup 40}Ca 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.

Dammalapati, U.; Willmann, L.; Knoop, S. [Kernfysisch Versneller Instituut (KVI), University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); LaserLaB Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands)

2011-11-15

420

Europium-doped barium bromide iodide  

SciTech Connect

Single crystals of Ba0.96Eu0.04BrI (barium europium bromide iodide) were grown by the Bridgman technique. The title compound adopts the ordered PbCl2 structure [Braekken (1932). Z. Kristallogr. 83, 222-282]. All atoms occupy the fourfold special positions (4c, site symmetry m) of the space group Pnma with a statistical distribution of Ba and Eu. They lie on the mirror planes, perpendicular to the b axis at y = +-0.25. Each cation is coordinated by nine anions in a tricapped trigonal prismatic arrangement.

Gundiah, Gautam; Hanrahan, Stephen M.; Hollander, Fredrick J.; Bourret-Courchesne, Edith D.

2009-10-21

421

Europium-doped barium bromide iodide.  

PubMed

Single crystals of Ba(0.96)Eu(0.04)BrI (barium europium bromide iodide) were grown by the Bridgman technique. The title compound adopts the ordered PbCl(2) structure [Braekken (1932 ?). Z. Kristallogr.83, 222-282]. All atoms occupy the fourfold special positions (4c, site symmetry m) of the space group Pnma with a statistical distribution of Ba and Eu. They lie on the mirror planes, perpendicular to the b axis at y = ±0.25. Each cation is coordinated by nine anions in a tricapped trigonal prismatic arrangement. PMID:21578035

Gundiah, Gautam; Hanrahan, Stephen M; Hollander, Frederick J; Bourret-Courchesne, Edith D

2009-01-01

422

Short-cavity squeezing in barium  

NASA Technical Reports Server (NTRS)

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.

Hope, D. M.; Bachor, H-A.; Manson, P. J.; Mcclelland, D. E.

1992-01-01

423

Scattering lengths of calcium and barium isotopes  

E-print Network

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.

U. Dammalapati; L. Willmann; S. Knoop

2011-10-25

424

Dielectric properties of barium titanate supramolecular nanocomposites.  

PubMed

Nanostructured dielectric composites can be obtained by dispersing high permittivity fillers, barium titanate (BTO) nanocubes, within a supramolecular framework. Thin films of BTO supramolecular nanocomposites exhibit a dielectric permittivity (?r) as high as 15 and a relatively low dielectric loss of ?0.1 at 1 kHz. These results demonstrate a new route to control the dispersion of high permittivity fillers toward high permittivity dielectric nanocomposites with low loss. Furthermore, the present study shows that the size distribution of nanofillers plays a key role in their spatial distribution and local ordering and alignment within supramolecular nanostructures. PMID:24584569

Lee, Keun Hyung; Kao, Joseph; Parizi, Saman Salemizadeh; Caruntu, Gabriel; Xu, Ting

2014-04-01

425

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

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?

Singh, Abhay Kumar; Ghosh, Tapan Kumar; Haldar, Sudipto

2015-04-01

426

Synthesis and characterization of barium iron oxide and bismuth iron oxide epitaxial films  

Microsoft Academic Search

Much interest exists in perovskite oxide materials and the potential they have in possessing two or more functional properties. In recent years, research on developing new materials with simultaneous ferromagnetic and ferroelectric behavior is the key to addressing possible challenges of new storage information applications. This work examines the fundamental properties of a perovskite oxide, namely BaFeO3, and the investigation

Charlee J. Callender Bennett

2009-01-01

427

Synthesis and characterization of barium iron oxide and bismuth iron oxide epitaxial films  

NASA Astrophysics Data System (ADS)

Much interest exists in perovskite oxide materials and the potential they have in possessing two or more functional properties. In recent years, research on developing new materials with simultaneous ferromagnetic and ferroelectric behavior is the key to addressing possible challenges of new storage information applications. This work examines the fundamental properties of a perovskite oxide, namely BaFeO3, and the investigation of properties of a solid solution between BaFeO3 and BiFeO3. The growth and properties of epitaxial BaFeO3 thin films in the metastable cubic perovskite phase are examined. BaFeO3 films were grown on (012) LaAlO3 and (001) SrTiO3 single crystal substrates by pulsed-laser deposition. X-ray diffraction shows that in situ growth at temperatures between 650-850°C yields an oxygen-deficient BaFeO 2.5+x pseudo-cubic perovskite phase that is insulating and paramagnetic. Magnetization measurements on the asdeposited BaFeO3 films indicate non-ferromagnetic behavior. Annealing these films in 1 atm oxygen ambient converts the films into a pseudo-cubic BaFeO3-x phase that is ferromagnetic with a Curie temperature of 235 K. The observation of ferromagnetism with increasing oxygen content is consistent with superexchange coupling of Fe +4-O-Fe+4. The effects of anneal conditions on BaFeO3 are studied. X-ray characterization, such as reciprocal space maps, show more complex structure for as-grown BaFeO3-x epitaxial films. Epitaxial films grown at low laser energies are highly crystalline. However, they decompose after annealing. When grown at high laser energies, films exhibit complex structure which "cleans up" to a single pseudocubic or tetragonal structure upon ex situ anneal in oxygen ambient environment. Superlattices of BaFeO 3/SrTiO3 were synthesized to explore the nature of "cracking" in annealed BaFeO3, which occurs due to large change in lattice parameter. Magnetization of ex situ annealed BaFeO3-x epitaxial films were examined as a function of applied field direction and was not found to have a change in magnetization with direction of field, despite other research claims. Evidence supports that the unusually weak magnetization of BaFeO3-x is attributed to it being structurally and magnetically disordered. Alloys of a solid-solution between BiFeO3 and BaFeO3-x have been successfully created. X-ray characterizations demonstrate alloy epitaxial films via two-target continuous rotation method have been carried all the way to 80% solubility. In addition, alloy films via solid-solution targets method have been successfully fabricated at near both end-member-points and at the half-point showing that the solubility is possible over the entire range of the solid-solution. Bi0.9Ba0.1FeO3 epitaxial films are of high crystalline quality with rocking curves widths of less than 0.22°, are fully strained, and have highly unusual in-plane and out-of-plane lattice parameters. TEM imaging illustrates that, despite extreme c/a ratios up to 1.26, the films are single phase with sharp interfaces with substrates. SQUID magnetometry was utilized, revealing that the samples are weakly ferromagnetic with a magnetization of 0.2microB per Fe, more than an order of magnitude larger than that of pure BiFeO3. Magnetic hysteresis loops show unfamiliar "pinching," signaling a possible breakdown of the helical magnetic ordering in the fully strained samples. BaFeO3-x, though it can be made ferromagnetic, it is a highly complex material. In studying BaFeO3-x's properties, conclusions can be made that its weak magnetization and unusual structure is highly disordered, magnetically and structurally. The creation of a new solid solution (Bi, Ba)FeO3 by two methods shows that a solid solution between BiFeO3 and BaFeO3-x can be synthesized. Specifically the creation of the alloy Bi0.9Ba0.1FeO3-delta , shows that one can improve on BiFeO3's magnetic properties, and more importantly supports the case that BaFeO3-x exhibits magnetic and structural disorder.

Callender Bennett, Charlee J.

428

Oxidation Potentials in Matte Smelting of Copper and Nickel  

NASA Astrophysics Data System (ADS)

The oxidation potential, given as the base-ten logarithm of the oxygen partial pressure in bars and the temperature [log pO2/ T, °C], defines the state of oxidation of pyrometallurgical extraction and refining processes. This property varies from copper making, [-6/1150]; to lead/zinc smelting, [-10/1200]; to iron smelting, [-13/1600]. The current article extends the analysis to the smelting of copper and nickel/copper sulfide concentrates to produce mattes of the type Cu(Ni)FeS(O) and iron silicate slags, FeOxSiO2—with oxidation potentials of [-7.5/1250].

Matousek, Jan W.

2014-09-01

429

BIOAVAILABILITY OF COPPER FROM COOKED DRY BEANS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The trace element copper (Cu) is a required nutrient in the diets of humans. It has been shown in animal studies to be essential for efficient absorption of iron, efficient oxygen utilization, and for aiding in free-radical degradation. Dry beans are potentially good sources of Cu; thus, the objecti...

430

Characteristics and antimicrobial activity of copper-based materials  

NASA Astrophysics Data System (ADS)

In this study, copper vermiculite was synthesized, and the characteristics, antimicrobial effects, and chemical stability of copper vermiculite were investigated. Two types of copper vermiculite materials, micron-sized copper vermiculite (MCV) and exfoliated copper vermiculite (MECV), are selected for this research. Since most of the functional fillers used in industry products, such as plastics, paints, rubbers, papers, and textiles prefer micron-scaled particles, micron-sized copper vermiculite was prepared by jet-milling vermiculite. Meanwhile, since the exfoliated vermiculite has very unique properties, such as high porosity, specific surface area, high aspect ratio of laminates, and low density, and has been extensively utilized as a functional additives, exfoliated copper vermiculite also was synthesized and investigated. The antibacterial efficiency of copper vermiculite was qualitatively evaluated by the diffusion methods (both liquid diffusion and solid diffusion) against the most common pathogenic species: Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Klebsiella pneumoniae (K. pneumoniae). The result showed that the release velocity of copper from copper vermiculite is very slow. However, copper vermiculite clearly has excellent antibacterial efficiency to S. aureus, K. pneumoniae and E. coli. The strongest antibacterial ability of copper vermiculite is its action on S. aureus. The antibacterial efficiency of copper vermiculite was also quantitatively evaluated by determining the reduction rate (death rate) of E. coli versus various levels of copper vermiculite. 10 ppm of copper vermiculite in solution is sufficient to reduce the cell population of E. coli, while the untreated vermiculite had no antibacterial activity. The slow release of copper revealed that the antimicrobial effect of copper vermiculite was due to the strong interactions between copper ions and bacteria cells. Exfoliated copper vermiculite has even stronger antibacterial activity than copper vermiculite against E. coli. With 200 ppm exfoliated copper vermiculite in bacteria suspension (4.68 ppm of metal copper), the reduction of viable bacteria are 99.8% at 1 hour, and >99.9% at 2 hours. With 10 ppm exfoliated copper vermiculite in bacteria dilution (0.234 ppm of copper atoms), the reduction of viable E. coli reached 98.7% at 1 hour, and >95.6% at 2 hours. Molds have the potential to cause health problems, such as allergic reactions, irritations, and mycotoxins, and damage to buildings, historic relics, properties, etc. Since copper has better antifungal property, an initial antifungal activity of copper vermiculite was evaluated in this study. Fat-free milk was used to develop molds in the test samples by saturated samples. Incubated at 36°C for 48 hours, all of the surfaces of untreated control samples, including micron-sized vermiculite, exfoliated vermiculite, bentonite, and kaolin, have been covered by thick mold layers. However, there were no mold showed on copper vermiculite and exfoliated copper vermiculite. Even after the incubation was lasted for 10 days, copper vermiculite and exfoliated copper vermiculite did not show any mold on the surface. These results exhibited copper vermiculite has excellent antifungal activities against mold. Stability of copper ions in copper vermiculite was measured by aqueous leaching process. Copper vermiculite and exfoliated copper vermiculite were put into distilled water in a ratio of 2.0g/100ml, and then implemented leaching processes by continuously shaking (leaching) and statically storing (soaking) for desired periods of time, respectively. According to the analytic result by inductively coupled plasma spectroscopy (ICP), the major metals released were copper, magnesium, iron, silicon, and aluminum. The release rate of copper depends on the environmental conditions. Under the dynamic leaching condition, all the major elements had shown linear leaching rates, and slowly increases along with the leaching time. Copper concentration in 1 hour leached solutions had suffi

Li, Bowen

431

Barium ferrite powders prepared by microwave-induced hydrothermal reaction and magnetic property  

Microsoft Academic Search

We have prepared barium ferrite particles by the microwave-induced hydrothermal method. The crystallization of the barium ferrite particles is promoted within a short time by microwave irradiation because the seeds of barium ferrite having large permeability are rapidly heated through the interaction of barium ferrite with the magnetic component of the microwaves. Crystals having unusually low thickness were obtained compared

Tomohisa Yamauchi; Yasunori Tsukahara; Takao Sakata; Hirotaro Mori; Tsukasa Chikata; Shunsaku Katoh; Yuji Wada

2009-01-01

432

Earthquake-induced barium anomalies in the Lisan Formation, Dead Sea Rift valley, Israel  

E-print Network

Earthquake-induced barium anomalies in the Lisan Formation, Dead Sea Rift valley, Israel Amitai Editor: L. Stixrude Keywords: barium Dead Sea seismite earthquake Lisan recurrence rate Prominent barium The present paper is a rst report of prominent barium concen- tration anomalies in seismically perturbed

Marco, Shmuel "Shmulik"

433

Fluid seepage along the San Clemente Fault scarp: basin-wide impact on barium cycling  

E-print Network

Fluid seepage along the San Clemente Fault scarp: basin-wide impact on barium cycling Marta E present evidence that the barium released at cold seeps along the San Clemente Fault zone may significantly impact the geochemical budget of barium within the basin. Barium fluxes at seep localities

Huh, Chih-An

434

Copper Cleanup  

NSDL National Science Digital Library

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.

2013-12-05

435

Investigation of magnetic properties in the case of three families of 1-dimensional magnets: M(II)A(4,4'-bipyridine); M = iron, cobalt, nickel, copper; A = chloride, nitrogen, (ox)  

NASA Astrophysics Data System (ADS)

Magnetic properties of three families of metal-organic coordinated networks which have the general form of M(II)A(4,4'-bipyridine), where M=Fe, Ni, Co, and Cu and A=Cl2, (ox) and (N3)2, are studied in this dissertation. Novel Ni(N3)2(4,4'-bipyridine), Co(N3)2(4,4'-bipyridine) and Cu(N 3)2(4,4'-bipyridine) have been synthesized. We applied different synthesis procedures and produced Ni, Co, and Cu azide compounds for the first time, thus leaving the hydrothermal route procedure. Powder x-ray diffraction at room temperature was done in order to establish the crystal structure of the members of these three families. It was found that all of them crystallize in orthorhombic structure, where transitional metals have an octahedral coordination. Since all three families have identical crystal structure we got opportunity to examine how ligands facilitate magnetic interaction between metallic centers and also to test existing magnetic theoretical models. Since 4,4'-bipyridine is much longer than other ligands, our systems can be considered as 1-D magnetic systems. Their interchain magnetic interactions are very weak, and they order magnetically at very low temperatures of the order of few K. Measurements of M(H) at temperatures T=1.9K and T=2K and chi(T) in different external magnetic fields in zero field and field cooled modes have been made. In the case of MCl2(4,4'-bipyridine) family of compounds, we observed ferromagnetic interactions between metal ions within the chains and antiferromagnetic interactions between adjacent chains. M(ox)(4,4'-bipyridine) family of metal-organic compounds has antiferromagnetic interactions between the transitional metal ions within the chain, while weak ferromagnetic interaction exists between the chains. All members in the M(N3)2(4,4'-bipyridine) family except in the case of the copper compound were found to have ferromagnetic interactions between metal ions within the chains and then antiferromagnetic interactions between adjacent chains. The copper compound does not show magnetic ordering in the temperature range we considered. All the metal ions in these compounds were detected in high spin states. The magnetic susceptibility data was fit to appropriate 1-D models, which in the case of MCl2(4,4'-bipyridine) and M(N3)2(4,4'-bipyridine) were the Classical Spin Fisher model, and the Bonner Fisher model in the case M(ox)(4,4'-bipyridine). The experimental results and fitting to the appropriate model with the accuracy of 0.995 suggests that shorter Cl-M-Cl distances facilitate ferromagnetic interactions, which are more sensitive to the total spin value then to the sole distance between metal ions. The magnetic behavior of M(N3) 2(4,4'-bipyridine) family of coordinated metal-organic compounds is very interesting because family members exhibit both ferromagnetic and antiferromagnetic behavior. The ferromagnetic characteristics decrease with decreasing spin. Fitting the results for all compounds of the M(ox)(4,4'-bipyridine) family have shown that strong anisotropy exists in all of them, being highest in Ni(ox)(4,'4-bipyridine) and lowest in Co(ox)(4,4'-bipyridine). Specific heat measurements were performed in the case of cobalt and copper azide compounds and then compared with previously obtained results for the iron coordinated network of the same family. Although none of these compounds show the characteristic lambda shaped transition indicating magnetic ordering, all of them have unusually large values of the constant gamma, which indicates significant magnetic contribution to the observed specific heat, since the free electron contribution in these observed families is negligible. We have concluded that total spin of the transitional metal plays a more important role than the distance between ions within the chain in determining magnitude of interaction, and that (N3)2 is a better facilitator of ferromagnetic interaction between ions than Cl2.

Danilovic, Dusan S.

436

Hygienic importance of increased barium content in some fresh waters.  

PubMed

In surface waters of the mining and processing areas of uranium ore there is an increased content of free and bound barium ions due to the use of barium salts for the treatment of waste and mine waters containing radium. In model experiments with the algae Ankistrodesmus falcatus, Chlorella kessleri and Scenedesmus obliquus, we studied the effect of Ba2+ on the accumulation of 226Ra. It was found that the accumulation of radium by algae is negatively influenced with barium concentrations higher than 1 mg.l-1. The accumulation of barium of organisms of primary production was studied using 133BaCl2. At a barium content in the medium of 4.0, 0.46 and 0.04 mu. l-1, the algae accumulated 30-60% of the added amount of barium during an exposure of 15 days. Biochemical analyses showed that barium is bound to the cellular membrane and to other components of the algal cell that cannot be extracted with water or alcohol. PMID:7462608

Havlík, B; Hanusová, J; Rálková, J

1980-01-01

437

Do all barium stars have a white dwarf companion?  

NASA Technical Reports Server (NTRS)

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.

Dominy, J. F.; Lambert, D. L.

1983-01-01

438

Iron-zinc based catalyst for the conversion of synthesis gas to alpha-olefins  

SciTech Connect

This patent describes a composition comprising iron, zinc, copper, an alkali metal selected from the group consisting of potassium, rubidium, cesium, or mixtures thereof, wherein the iron:zinc atomic ratio is at least about 5:1, and the alkali metal:copper atomic ratio is at least about 2:1.

Soled, S.L.; Miseo, S.; Iglesia, E.; Fiato, R.A.

1992-03-31

439

Microstructure and magnetism in barium strontium titanate (BSTO)-barium hexaferrite (BaM) multilayers  

SciTech Connect

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.

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

440

Migration and redistribution of oxygen vacancy in barium titanate ceramics  

SciTech Connect

Degradation of barium titanate based multilayer capacitor mainly results from migration and redistribution of oxygen vacancy. For barium titanate ceramics, the authors observe an internal friction relaxation peak around 70 deg. C due to oxygen vacancy, and its relaxation strength differs greatly for specimen aged at 85 deg. C for 120 h and at 150 deg. C for 5 h. Two possible explanations are proposed, one based on symmetry-conforming short-range order while the other on the interaction between oxygen vacancy and domain wall during aging process. In any case, relaxation thermodynamics is a powerful tool to investigate the migration and redistribution of oxygen vacancy in barium titanate ceramics.

Chen, L.; Xiong, X. M.; Meng, H.; Lv, P.; Zhang, J. X. [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

2006-08-14

441

Microstructure and magnetic properties of low-temperature sintered CoTi-substituted barium ferrite for LTCC application  

Microsoft Academic Search

In this article, the influences of the BaCu(B2O5) (BCB) additive on sintering behavior, structure and magnetic properties of iron deficient M-type barium ferrite Ba(CoTi)xFe11.8?2xO19 (BaM) have been investigated. It is found that the maximum sintered densities of BaM change from 86% to 94% as the BCB content varies from 1 to 4wt%. Single-phase BaM can be detected by the XRD

Daming Chen; Yingli Liu; Yuanxun Li; Wenguo Zhong; Huaiwu Zhang

2011-01-01

442

Designed microstructures in textured barium hexaferrite  

NASA Astrophysics Data System (ADS)

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.

Hovis, David Brian

443

Dispersion strengthened copper  

DOEpatents

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.

Sheinberg, H.; Meek, T.T.; Blake, R.D.

1990-01-09

444