Sample records for copper selenides

  1. Formation of copper-indium-selenide and\\/or copper-indium-gallium-selenide films from indium selenide and copper selenide precursors

    Microsoft Academic Search

    Calvin J. Curtis; Alexander Miedaner; Maikel Van Hest; David S. Ginley; Jennifer A. Nekuda

    2011-01-01

    Liquid-based indium selenide and copper selenide precursors, including copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent, are used to form crystalline copper-indium-selenide, and\\/or copper indium gallium selenide films (66) on substrates (52).

  2. Formation of copper-indium-selenide and/or copper-indium-gallium-selenide films from indium selenide and copper selenide precursors

    SciTech Connect

    Curtis, Calvin J. (Lakewood, CO); Miedaner, Alexander (Boulder, CO); Van Hest, Maikel (Lakewood, CO); Ginley, David S. (Evergreen, CO); Nekuda, Jennifer A. (Lakewood, CO)

    2011-11-15

    Liquid-based indium selenide and copper selenide precursors, including copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent, are used to form crystalline copper-indium-selenide, and/or copper indium gallium selenide films (66) on substrates (52).

  3. 40 CFR 721.10391 - Copper gallium indium selenide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Copper gallium indium selenide. 721.10391...Chemical Substances § 721.10391 Copper gallium indium selenide. (a) Chemical...The chemical substance identified as copper gallium indium selenide (PMN...

  4. 40 CFR 721.10391 - Copper gallium indium selenide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Copper gallium indium selenide. 721.10391...Chemical Substances § 721.10391 Copper gallium indium selenide. (a) Chemical...The chemical substance identified as copper gallium indium selenide (PMN...

  5. 40 CFR 721.10391 - Copper gallium indium selenide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Copper gallium indium selenide. 721.10391...Chemical Substances § 721.10391 Copper gallium indium selenide. (a) Chemical...The chemical substance identified as copper gallium indium selenide (PMN...

  6. Anisotropic thermal expansion of copper gallium selenide

    Microsoft Academic Search

    P. Kistaiah; Y. C. Venudhar; K. Sathyanarayana Murthy; L. Iyengar; K. V. Krishna Rao

    1981-01-01

    Unit-cell parameters for the chalcopyrite type ternary semiconducting compound copper gallium selenide (CuGaSe2) have been determined accurately, using the least-squares method, for reflections in the range of Bragg angles 64-82 degrees , by the X-ray powder diffraction method. A study of the thermal expansion of the chalcopyrite structure unit-cell of the compound, determined over the temperature range 28-685 degrees C,

  7. Incorporation of copper into indium gallium selenide layers from solution

    Microsoft Academic Search

    C. J. Hibberd; M. Ganchev; M. Kaelin; K. Ernits; A. N. Tiwari

    2008-01-01

    A chemical method for the incorporation of copper into indium gallium selenide (IGS) layers has been developed. The resulting copper-containing precursor layers have been annealed in the presence of selenium vapour with the goal of forming Cu(In, Ga)Se2 (CIGS) layers. It is found that copper ions in solution are incorporated into IGS layers during immersion, resulting in the formation of

  8. Copper Indium Gallium Selenide photovoltaic modules manufactured by reactive transfer

    Microsoft Academic Search

    Dingyuan Lu; Baosheng Sang; Yuepeng Deng; B. J. Stanbery; L. Eldada

    2010-01-01

    In recent years, thin-film photovoltaic companies, especially First Solar with its CdTe technology, managed to realize the low manufacturing cost potential and to grab an increasingly larger market share. Copper Indium Gallium Selenide is the most promising thin-film PV material, having demonstrated the highest energy conversion efficiency in both cells and modules. However, most CIGS manufacturers still face the challenge

  9. Ambient Facile Synthesis of Gram-Scale Copper Selenide Nanostructures from Commercial Copper and Selenium Powder.

    PubMed

    Chen, Xin Qi; Li, Zhen; Dou, Shi Xue

    2015-06-24

    Grams of copper selenides (Cu2-xSe) were prepared from commercial copper and selenium powders in the presence of thiol ligands by a one-pot reaction at room temperature. The resultant copper selenides are a mixture of nanoparticles and their assembled nanosheets, and the thickness of nanosheets assembled is strongly dependent on the ratio of thiol ligand to selenium powder. The resultant Cu2-xSe nanostructures were treated with hydrazine solution to remove the surface ligands and then explored as a potential thermoelectric candidate in comparison with commercial copper selenide powders. The research provides a novel ambient approach for preparation of Cu2-xSe nanocrystallines on a large scale for various applications. PMID:26020682

  10. Copper-indium-selenide quantum dot-sensitized solar cells.

    PubMed

    Yang, Jiwoong; Kim, Jae-Yup; Yu, Jung Ho; Ahn, Tae-Young; Lee, Hyunjae; Choi, Tae-Seok; Kim, Young-Woon; Joo, Jin; Ko, Min Jae; Hyeon, Taeghwan

    2013-12-21

    We present a new synthetic process of near infrared (NIR)-absorbing copper-indium-selenide (CISe) quantum dots (QDs) and their applications to efficient and completely heavy-metal-free QD-sensitized solar cells (QDSCs). Lewis acid-base reaction of metal iodides and selenocarbamate enabled us to produce chalcopyrite-structured CISe QDs with controlled sizes and compositions. Furthermore, gram-scale production of CISe QDs was achieved with a high reaction yield of ~73%, which is important for the commercialization of low-cost photovoltaic (PV) devices. By changing the size and composition, electronic band alignment of CISe QDs could be finely tuned to optimize the energetics of the effective light absorption and injection of electrons into the TiO2 conduction band (CB). These energy-band-engineered QDs were applied to QDSCs, and the quantum-confinement effect on the PV performances was clearly demonstrated. Our best cell yielded a conversion efficiency of 4.30% under AM1.5G one sun illumination, which is comparable to the performance of the best solar cells based on toxic lead chalcogenide or cadmium chalcogenide QDs. PMID:24177572

  11. Photoconductivity in reactively evaporated copper indium selenide thin films

    SciTech Connect

    Urmila, K. S., E-mail: urmilaks7@gmail.com; Asokan, T. Namitha, E-mail: urmilaks7@gmail.com; Pradeep, B., E-mail: urmilaks7@gmail.com [Solid State Physics Laboratory, Cochin University of Science and Technology, Kochi, Kerala (India); Jacob, Rajani; Philip, Rachel Reena [Thin Film Research Laboratory, Union Christian College, Aluva, Kerala (India)

    2014-01-28

    Copper indium selenide thin films of composition CuInSe{sub 2} with thickness of the order of 130 nm are deposited on glass substrate at a temperature of 423 ±5 K and pressure of 10{sup ?5} mbar using reactive evaporation, a variant of Gunther's three temperature method with high purity Copper (99.999%), Indium (99.999%) and Selenium (99.99%) as the elemental starting materials. X-ray diffraction (XRD) studies shows that the films are polycrystalline in nature having preferred orientation of grains along the (112) plane. The structural type of the film is found to be tetragonal with particle size of the order of 32 nm. The structural parameters such as lattice constant, particle size, dislocation density, number of crystallites per unit area and strain in the film are also evaluated. The surface morphology of CuInSe{sub 2} films are studied using 2D and 3D atomic force microscopy to estimate the grain size and surface roughness respectively. Analysis of the absorption spectrum of the film recorded using UV-Vis-NIR Spectrophotometer in the wavelength range from 2500 nm to cutoff revealed that the film possess a direct allowed transition with a band gap of 1.05 eV and a high value of absorption coefficient (?) of 10{sup 6} cm{sup ?1} at 570 nm. Photoconductivity at room temperature is measured after illuminating the film with an FSH lamp (82 V, 300 W). Optical absorption studies in conjunction with the good photoconductivity of the prepared p-type CuInSe{sub 2} thin films indicate its suitability in photovoltaic applications.

  12. Photoconductivity in reactively evaporated copper indium selenide thin films

    NASA Astrophysics Data System (ADS)

    Urmila, K. S.; Asokan, T. Namitha; Pradeep, B.; Jacob, Rajani; Philip, Rachel Reena

    2014-01-01

    Copper indium selenide thin films of composition CuInSe2 with thickness of the order of 130 nm are deposited on glass substrate at a temperature of 423 ±5 K and pressure of 10-5 mbar using reactive evaporation, a variant of Gunther's three temperature method with high purity Copper (99.999%), Indium (99.999%) and Selenium (99.99%) as the elemental starting materials. X-ray diffraction (XRD) studies shows that the films are polycrystalline in nature having preferred orientation of grains along the (112) plane. The structural type of the film is found to be tetragonal with particle size of the order of 32 nm. The structural parameters such as lattice constant, particle size, dislocation density, number of crystallites per unit area and strain in the film are also evaluated. The surface morphology of CuInSe2 films are studied using 2D and 3D atomic force microscopy to estimate the grain size and surface roughness respectively. Analysis of the absorption spectrum of the film recorded using UV-Vis-NIR Spectrophotometer in the wavelength range from 2500 nm to cutoff revealed that the film possess a direct allowed transition with a band gap of 1.05 eV and a high value of absorption coefficient (?) of 106 cm-1 at 570 nm. Photoconductivity at room temperature is measured after illuminating the film with an FSH lamp (82 V, 300 W). Optical absorption studies in conjunction with the good photoconductivity of the prepared p-type CuInSe2 thin films indicate its suitability in photovoltaic applications.

  13. Nanoscale self-assembly of high-efficiency copper indium gallium selenide photovoltaic thin films

    Microsoft Academic Search

    Louay Eldada

    2009-01-01

    We demonstrate photovoltaic integrated circuits (PVIC) with high-quality large-grain Copper Indium Gallium Selenide (CIGS) obtained with the unique combination of low-cost ink-based or Physical Vapor Deposition (PVD) based nanoengineered precursor thin films and a reactive transfer printing method. Reactive transfer is a two-stage process relying on chemical reaction between two separate precursor films to form CIGS, one deposited on the

  14. Spectroscopic Ellipsometry Characterization of Variable Cu Concentration in Copper Indium Gallium di-Selenide Photovoltaic Films

    Microsoft Academic Search

    J. C. Verley; T. E. Furtak

    2000-01-01

    Copper indium gallium di-selenide (CIGS) is among the most promising thin-film photovoltaic (PV) materials. Solar cells, using CIGS as an absorber layer, have achieved greater than 18 percent power conversion efficiencies on the laboratory scale. The best CIGS based photovoltaics have been created by utilizing the so-called three-stage process for the growth of the absorber layer. Standard substrates consist of

  15. Passive laser Q switches made of glass doped with oxidised nanoparticles of copper selenide

    SciTech Connect

    Yumashev, K V [International Laser Center, Belarus State Technical University, Minsk (Belarus)

    2000-01-31

    Passive Q switching of Nd{sup 3+}:YAG ({lambda} = 1060 nm) and YAlO{sub 3}:Nd{sup 3+} (1340 nm) lasers, as well as of an Er{sup 3+} (1540 nm) glass laser was realised by using glass doped with oxidised nanoparticles of copper selenide. Nonlinear optical properties of the nanoparticles (radius of 25 nm) in a glass matrix were studied by the picosecond absorption spectroscopy technique. (control of laser radiation parameters)

  16. Copper selenide nanowires and nanocrystallites in alumina: Carrier relaxation, recombination, and trapping

    NASA Astrophysics Data System (ADS)

    Statkut?, G.; Tomašiùnas, R.; Jagminas, A.

    2007-06-01

    Nonequilibrium carrier dynamics in copper selenide (Cu2-?Se ?=0.15, Cu3Se2) nanowires (diameter ?18 nm, height ?2 ?m) and nanocrystallites (diameter?18 nm) in femto- and picosecond time domains by the means of a transient dynamic grating technique were investigated. Bulk and quantum confinement approaches were used to fit the experimental results using nonequilibrium carrier fast relaxation, recombination, and trapping mechanisms. A nonradiative Auger recombination was concluded to be the main mechanism of nonequilibrium carrier recombination. The Auger coefficient for copper selenide was estimated of the order of 10-30-10-29 cm6 s-1. Hole trapping at shallow impurity centers in nanowires was interpreted. From calculating the experimental results the trapping parameters and high concentration of centers >1020 cm-3 were evaluated. Finally, direct measurement of carrier lifetime in copper selenide nanostructures showed values of the order of ?10-10 s. Samples were characterized by the means of transmission electron microscopy, scanning electron microscopy, x-ray diffraction, and optical spectroscopy.

  17. Copper and silver selenide crystal growth rate measurements as a method for determination of ionic conductivity

    NASA Astrophysics Data System (ADS)

    Vu?i?, Zlatko; Lovri?, Davorin; Gladi?, Jadranko; Etlinger, Božidar

    2004-03-01

    The motivation behind this work is the discrepancy between the measured and calculated growth rates of copper selenide spherical single crystals between 740 and 800 K. The growth of cylindrical polycrystalline samples of copper selenide at high temperatures was monitored in experiments that enabled full control of the geometry of growth. Together with the calculations based on Yokota's transport equation, these measurements eliminated ionic conductivity data as a possible reason behind too high values of the calculated growth rates. The equivalent growth experiments on polycrystalline silver selenide samples were performed as a test of the method, yielding excellent agreement with the results obtained by extrapolation of existing data. On the basis of these measurements and associated analysis, this method is proposed as a method for determination of ionic conductivity of mixed superionic conductors on temperatures up to the temperatures of melting, i.e. in the range in which other methods of ionic conductivity measurements either do not work or are not accurate enough.

  18. Band structure and transport studies of copper selenide: An efficient thermoelectric material

    NASA Astrophysics Data System (ADS)

    Tyagi, Kriti; Gahtori, Bhasker; Bathula, Sivaiah; Auluck, S.; Dhar, Ajay

    2014-10-01

    We report the band structure calculations for high temperature cubic phase of copper selenide (Cu2Se) employing Hartree-Fock approximation using density functional theory within the generalized gradient approximation. These calculations were further extended to theoretically estimate the electrical transport coefficients of Cu2Se employing Boltzmann transport theory, which show a reasonable agreement with the corresponding experimentally measured values. The calculated transport coefficients are discussed in terms of the thermoelectric (TE) performance of this material, which suggests that Cu2Se can be a potential p-type TE material with an optimum TE performance at a carrier concentration of ˜ 4 - 6 × 10 21 cm - 3 .

  19. Methods of making copper selenium precursor compositions with a targeted copper selenide content and precursor compositions and thin films resulting therefrom

    DOEpatents

    Curtis, Calvin J. (Lakewood, CO); Miedaner, Alexander (Boulder, CO); van Hest, Marinus Franciscus Antonius Maria (Lakewood, CO); Ginley, David S. (Evergreen, CO); Leisch, Jennifer (Denver, CO); Taylor, Matthew (West Simsbury, CT); Stanbery, Billy J. (Austin, TX)

    2011-09-20

    Precursor compositions containing copper and selenium suitable for deposition on a substrate to form thin films suitable for semi-conductor applications. Methods of forming the precursor compositions using primary amine solvents and methods of forming the thin films wherein the selection of temperature and duration of heating controls the formation of a targeted species of copper selenide.

  20. A nanoparticle ink printing process for all printed thin film copper-indium-selenide (CIS) solar cells

    Microsoft Academic Search

    X. Charles Li; Istvan Soltesz; Mindy Wu; Frank Ziobro; Roger Amidon; Zoltan Kiss

    2008-01-01

    Copper indium selenide (CIS) or its derivatives (such as gallium doped CIS and sulfur substituted CIS) are considered the best optical absorber material used in polycrystalline thin film photovoltaic solar cells due to their favorable electrical and optical properties, and long term stability. To develop a low cost yet high throughput thin film deposition process with both composition and film

  1. Investigation of copper indium gallium selenide material growth by selenization of metallic precursors

    NASA Astrophysics Data System (ADS)

    Han, Junfeng; Liao, Cheng; Jiang, Tao; Xie, Huamu; Zhao, Kui; Besland, M.-P.

    2013-11-01

    We report a study of copper indium gallium selenide (CIGS) thin film growth in the annealing process at temperature range from 120 °C to 600 °C. Thin films were prepared by sputtering metal precursors and subsequent selenization process. Surface morphologies of thin films were observed by using high resolution field emission scanning electron microscopy (FESEM). Phases in quaternary systems Cu-In-Ga-Se were investigated by X-ray diffraction (XRD). Evolution of crystalline structure in the film surface was studied by Raman spectra. A possible reaction path from metallic precursors to a single CIGS phase was obtained by merging all results of SEM, XRD and Raman. Above 210 °C, selenium reacted with Cu and In to form binary selenide. CuSe crystalline platelets were observed clearly in the film surfaces. When temperature was reaching 380 °C, Cu2-xSe and InSe reacted with excess Se to form CuInSe2 (CIS) and contributed to the grain growth. Above 410 °C, Ga-rich phase was detected in the films. With increased temperature, Ga diffused into CIS crystalline lattices. Finally, at 600 °C, a single phase of Cu-In-Ga-Se quaternary system was formed. A large number of triangular and hexagonal structures were observed in the film due to a re-crystalline process at a high annealing temperature.

  2. Chemical bath deposited zinc sulfide buffer layers for copper indium gallium sulfur-selenide solar cells and device analysis

    Microsoft Academic Search

    Sambhu N. Kundu; Larry C. Olsen

    2005-01-01

    Cadmium-free copper indium gallium sulfur-selenide (CIGSS) thin film solar cells have been fabricated using chemical bath deposited (CBD) zinc sulfide (ZnS) buffer layers. Shell Solar Industries provided high quality CIGSS absorber layers. The use of CBD-ZnS, which is a higher band gap material than CdS, improved the quantum efficiency of fabricated cells at lower wavelengths, leading to an increase in

  3. Spectroscopic Ellipsometry Characterization of Variable Cu Concentration in Copper Indium Gallium di-Selenide Photovoltaic Films

    NASA Astrophysics Data System (ADS)

    Verley, J. C.; Furtak, T. E.

    2000-03-01

    Copper indium gallium di-selenide (CIGS) is among the most promising thin-film photovoltaic (PV) materials. Solar cells, using CIGS as an absorber layer, have achieved greater than 18 percent power conversion efficiencies on the laboratory scale. The best CIGS based photovoltaics have been created by utilizing the so-called three-stage process for the growth of the absorber layer. Standard substrates consist of soda-lime glass coated with Mo, which serves as the back contact. Despite their successful performance, the characteristics of CIGS films are poorly understood. The relative amount of Cu in the absorber layer during and after growth is an important variable in the creation of high quality PV material. We have investigated the properties of PV quality CIGS films using spectroscopic, variable angle ellipsometry, which is sensitive to the films’ band-edge and graded profile optical characteristics. The films were prepared with various mid-growth and post-growth Cu concentrations, following the standard procedures described above.

  4. Nanoscale self-assembly of high-efficiency copper indium gallium selenide photovoltaic thin films

    NASA Astrophysics Data System (ADS)

    Eldada, Louay

    2009-08-01

    We demonstrate photovoltaic integrated circuits (PVIC) with high-quality large-grain Copper Indium Gallium Selenide (CIGS) obtained with the unique combination of low-cost ink-based or Physical Vapor Deposition (PVD) based nanoengineered precursor thin films and a reactive transfer printing method. Reactive transfer is a two-stage process relying on chemical reaction between two separate precursor films to form CIGS, one deposited on the substrate and the other on a printing plate in the first stage. In the second stage, these precursors are brought into intimate contact and rapidly reacted under pressure in the presence of an electrostatic field while heat is applied. The use of two independent thin films provides the benefits of independent composition and flexible deposition technique optimization, and eliminates pre-reaction prior to the synthesis of CIGS. High quality CIGS with large grains on the order of several microns, and of preferred crystallographic orientation, are formed in just several minutes based on compositional and structural analysis by XRF, SIMS, SEM and XRD. Cell efficiencies of 14% and module efficiencies of 12% have been achieved using this method. When atmospheric pressure deposition of inks is utilized for the precursor films, the approach additionally provides further reduced capital equipment cost, lower thermal budget, and higher throughput.

  5. A nanoparticle ink printing process for all printed thin film copper-indium-selenide (CIS) solar cells

    NASA Astrophysics Data System (ADS)

    Li, X. Charles; Soltesz, Istvan; Wu, Mindy; Ziobro, Frank; Amidon, Roger; Kiss, Zoltan

    2008-08-01

    Copper indium selenide (CIS) or its derivatives (such as gallium doped CIS and sulfur substituted CIS) are considered the best optical absorber material used in polycrystalline thin film photovoltaic solar cells due to their favorable electrical and optical properties, and long term stability. To develop a low cost yet high throughput thin film deposition process with both composition and film uniformity control, precursor ink has been formulated using nanoparticle metal oxide of copper and indium in an organic solvent system dissolved with selenium or sulfur. Smooth thin film of precursor oxide mixture has been demonstrated by wet printing process. Upon heat treatment of the precursor thin film under atmosphere of selenium and/or sulfur, copper-indium selenide and/or sulfide (CIS) was formed. Several approaches of nanoparticle ink coating processes have been investigated through spin-coating, screen-printing and contact printing. For using glass substrate, contact printing demonstrated superior uniformity and composition control. By using a post-thermal treatment process on the nanoparticle-coated film, good morphology thin film with composition control was achieved. Both the chemical composition and physical morphology has been investigated using ICP-OES and XRD measurements. Based on molybdenum glass substrate, all-printed solar cells have been demonstrated.

  6. Nanocrystalline dye-sensitized solar cell/copper indium gallium selenide thin-film tandem showing greater than 15% conversion efficiency

    NASA Astrophysics Data System (ADS)

    Liska, P.; Thampi, K. R.; Grätzel, M.; Brémaud, D.; Rudmann, D.; Upadhyaya, H. M.; Tiwari, A. N.

    2006-05-01

    Multijunction stacked (tandem) solar cells can increase the overall photovoltaic conversion efficiency by optimal utilization of the solar spectrum in individual cells. We demonstrate that a photovoltaic tandem cell comprising a nanocrystalline dye-sensitized solar cell as a top cell for high-energy photons and a copper indium gallium selenide thin-film bottom cell for lower-energy photons produces AM 1.5 solar to electric conversion efficiencies greater than 15%.

  7. Nanocrystalline dye-sensitized solar cell\\/copper indium gallium selenide thin-film tandem showing greater than 15% conversion efficiency

    Microsoft Academic Search

    P. Liska; K. R. Thampi; D. Bre´maud; D. Rudmann; H. M. Upadhyaya; A. N. Tiwari

    2006-01-01

    Multijunction stacked (tandem) solar cells can increase the overall photovoltaic conversion efficiency by optimal utilization of the solar spectrum in individual cells. We demonstrate that a photovoltaic tandem cell comprising a nanocrystalline dye-sensitized solar cell as a top cell for high-energy photons and a copper indium gallium selenide thin-film bottom cell for lower-energy photons produces AM 1.5 solar to electric

  8. A study on the optics of copper indium gallium (di)selenide (CIGS) solar cells with ultra-thin absorber layers.

    PubMed

    Xu, Man; Wachters, Arthur J H; van Deelen, Joop; Mourad, Maurice C D; Buskens, Pascal J P

    2014-03-10

    We present a systematic study of the effect of variation of the zinc oxide (ZnO) and copper indium gallium (di)selenide (CIGS) layer thickness on the absorption characteristics of CIGS solar cells using a simulation program based on finite element method (FEM). We show that the absorption in the CIGS layer does not decrease monotonically with its layer thickness due to interference effects. Ergo, high precision is required in the CIGS production process, especially when using ultra-thin absorber layers, to accurately realize the required thickness of the ZnO, cadmium sulfide (CdS) and CIGS layer. We show that patterning the ZnO window layer can strongly suppress these interference effects allowing a higher tolerance in the production process. PMID:24922252

  9. Characterization of copper selenide thin film hole-injection layers deposited at room temperature for use with p-type organic semiconductors

    NASA Astrophysics Data System (ADS)

    Hiramatsu, Hidenori; Koizumi, Ikue; Kim, Ki-Beom; Yanagi, Hiroshi; Kamiya, Toshio; Hirano, Masahiro; Matsunami, Noriaki; Hosono, Hideo

    2008-12-01

    Copper selenide, CuxSe(x ˜2), was examined as a hole-injection layer for low-temperature organic devices. Crystalline CuxSe films grown at room temperature with atomically flat surfaces exhibited metallic conduction with a high electrical conductivity of 4.5×103 S/cm, a hole concentration of 1.4×1022 cm-3, and a mobility of 2.0 cm2/(V s). Analysis of the free carrier absorption using the Drude model estimated the effective mass of a hole as 1.0me. Photoemission spectroscopy measurements of the interfaces between CuxSe and organic hole transport layers, N ,N'-bis(naphthalen-1-yl)-N ,N'-bis(phenyl) benzidine (NPB) and copper phthalocyanine (CuPc), verified that the hole-injection barriers of these interfaces (0.4 eV for NPB and 0.3 eV for CuPc) are smaller than that of a conventional indium tin oxide (ITO) hole-injection electrode/NPB interface (0.6 eV) but are comparable to that of an ITO electrode/CuPc interface (0.3 eV). Hole-only devices using the CuxSe layer as a hole-injection anode exhibited very low threshold voltages (0.4-0.5 V) and nearly Ohmic characteristics. The NPB layer on the CuxSe layer was found to be highly doped at 1017-1019 cm-3, probably due to copper diffusion, while the CuPc layer is nearly intrinsic with a doping concentration lower than 1015 cm-3. These results indicated that a CuxSe film combined with CuPc is a promising candidate for a low-voltage hole-injection anode or a buffer layer in low-temperature devices such as organic light-emitting diodes and thin film transistors.

  10. Formation of selenide, sulfide or mixed selenide-sulfide films on metal or metal coated substrates

    DOEpatents

    Eser, Erten; Fields, Shannon

    2012-05-01

    A process and composition for preventing cracking in composite structures comprising a metal coated substrate and a selenide, sulfide or mixed selenide sulfide film. Specifically, cracking is prevented in the coating of molybdenum coated substrates upon which a copper, indium-gallium diselenide (CIGS) film is deposited. Cracking is inhibited by adding a Se passivating amount of oxygen to the Mo and limiting the amount of Se deposited on the Mo coating.

  11. Dimethyl selenide complexes of copper, gallium and indium halides as potential precursors for selenium-containing chalcopyrite semiconducting materials

    Microsoft Academic Search

    Shashank Mishra; Erwann Jeanneau; Stéphane Daniele

    2010-01-01

    The coordination chemistry of copper, gallium and indium halides with the simplest possible selenoether i.e. Me2Se was investigated with the aim to use the resulting complexes as precursors for selenium-containing chalcopyrite semiconducting materials. An optimized general procedure for the high yield synthesis is described and the influence of a halide ion on the structure and solubility of these metal halide

  12. Neutralization by Metal Ions of the Toxicity of Sodium Selenide

    PubMed Central

    Dauplais, Marc; Lazard, Myriam; Blanquet, Sylvain; Plateau, Pierre

    2013-01-01

    Inert metal-selenide colloids are found in animals. They are believed to afford cross-protection against the toxicities of both metals and selenocompounds. Here, the toxicities of metal salt and sodium selenide mixtures were systematically studied using the death rate of Saccharomyces cerevisiae cells as an indicator. In parallel, the abilities of these mixtures to produce colloids were assessed. Studied metal cations could be classified in three groups: (i) metal ions that protect cells against selenium toxicity and form insoluble colloids with selenide (Ag+, Cd2+, Cu2+, Hg2+, Pb2+ and Zn2+), (ii) metal ions which protect cells by producing insoluble metal-selenide complexes and by catalyzing hydrogen selenide oxidation in the presence of dioxygen (Co2+ and Ni2+) and, finally, (iii) metal ions which do not afford protection and do not interact (Ca2+, Mg2+, Mn2+) or weakly interact (Fe2+) with selenide under the assayed conditions. When occurring, the insoluble complexes formed from divalent metal ions and selenide contained equimolar amounts of metal and selenium atoms. With the monovalent silver ion, the complex contained two silver atoms per selenium atom. Next, because selenides are compounds prone to oxidation, the stabilities of the above colloids were evaluated under oxidizing conditions. 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB), the reduction of which can be optically followed, was used to promote selenide oxidation. Complexes with cadmium, copper, lead, mercury or silver resisted dissolution by DTNB treatment over several hours. With nickel and cobalt, partial oxidation by DTNB occurred. On the other hand, when starting from ZnSe or FeSe complexes, full decompositions were obtained within a few tens of minutes. The above properties possibly explain why ZnSe and FeSe nanoparticles were not detected in animals exposed to selenocompounds. PMID:23342137

  13. Improving the efficiency of copper indium gallium (Di-)selenide (CIGS) solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    NASA Astrophysics Data System (ADS)

    Burghoorn, M.; Kniknie, B.; van Deelen, J.; Xu, M.; Vroon, Z.; van Ee, R.; van de Belt, R.; Buskens, P.

    2014-12-01

    Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (Jsc) and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transparent conductor in copper indium gallium (di-)selenide (CIGS) solar cells is also optically advantageous. Here, we experimentally demonstrate that the Jsc and efficiency of CIGS solar cells with an absorber layer thickness (dCIGS) of 0.85 ?m, 1.00 ?m and 2.00 ?m increase through application of a moth-eye textured resist with a refractive index that is sufficiently similar to AZO (nresist = 1.792 vs. nAZO = 1.913 at 633 nm) to avoid large optical losses at the resist-AZO interface. On average, Jsc increases by 7.2%, which matches the average reduction in reflection of 7.0%. The average relative increase in efficiency is slightly lower (6.0%). No trend towards a larger relative increase in Jsc with decreasing dCIGS was observed. Ergo, the increase in Jsc can be fully explained by the reduction in reflection, and we did not observe any increase in Jsc based on an increased photon path length.

  14. Development of the data base for a degradation model of a selenide RTG. [Radioisotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Stapfer, G.; Truscello, V. C.

    1977-01-01

    The paper is concerned with the evaluation of the materials used in a selenide radioisotope thermoelectric generator (RTG). These materials are composed of n-type gadolinium selenide and n-type copper selenide. A three-fold evaluation approach is being used: (1) the study of the rate of change of the thermal conductivity of the material, (2) the investigation of the long-term stability of the material's Seebeck voltage and electrical resistivity under current and temperature gradient conditions, and (3) determination of the physical behavior and compatibility of the material with surrounding insulation at elevated temperatures. Programmatically, the third category of characteristic evaluation is being emphasized.

  15. Molecular Structure of Hydrogen Selenide

    NSDL National Science Digital Library

    2003-06-04

    Hydrogen Selenide is a colorless toxic gas with a foul penetrating odor that it is extremely flammable and can form explosive mixture with air. It is used for the preparation of metallic selenides and organoselenium compounds. It is also used as a dopant gas for preparation of semiconductor materials for use in lasers, solar cells and other equipment containing controlled amounts of significant impurities.

  16. COPPER(1-Y)SILVER(Y)INDIUM - DISULFIDE(1-X)SELENIDE(2X) as a Prototype of the Pentenary Chalcopyrite Semiconductor Systems.

    NASA Astrophysics Data System (ADS)

    Chapman, Glenn Harrison

    The group III-V mixed alloy quarternary semiconductors, such as Ga(,(1-y))In(,y)As(,(1-x))P(,x) have been extensively employed in lattice matching different semiconducting layers (at specific bandgaps) to form heterojunction electro-optical devices. However, these cover only a limited set of direct bandgap/lattice constant combinations. The analogous pentenary alloys, consisting of the ternary chalcopyrite groups I -III-VI(,2) and II-IV-V(,2), have the potential of similar applications as they cover an even wider band/lattice range. As a prototype of such alloys, samples of the pentenary Cu(,(1 -y))Ag(,y)InS(,2(1-x))Se(,2x) have been synthesized and studied. Samples were prepared by reacting stoichimetric powder mixtures at about 900 C. X-ray diffractometry tests suggest the compounds maintained complete powder solid solubility throughout the system in the chalcopyrite crystal structure. The intrinsic conductivity type of the alloys appear to follow a trend towards n-type for silver and sulfur rich compounds, while forming p-type for copper and selenium rich materials. The bandgap of these samples were measured using cathodoluminescence techniques, which generally have some ambiguity in their resulting estimates. To generate better values of the band parameters extensive computer modeling for the emission spectra from heavily doped direct bandgap materials was done. The effect of band tails and Gaussian impurity states on the luminescence spectra was studied for changes in doping densities, temperature and carrier injection levels. Formulae were derived from these models to obtain better estimates of the bandgap and impurity activation levels. Algorithms were developed to obtain the impurity spreading energy of a tailed or Gaussian band, and the quasi-Fermi energy levels for injected current in a material with a specific band structure. Cathodoluminescence measurements were made at 300 and 77 K on the samples. As predicted by the models, it was found easier to generate good estimates from the 300 K results due to the obscuring effects of the impurity bands at cooler temperatures. Using these band estimates least squares fits were made on the data to generate the topological bandgap/lattice constant versus compositional value maps for the studied alloy.

  17. Advanced selenide thermoelectric development program. Final report

    SciTech Connect

    Seetoo, W.R.

    1981-07-20

    The primary objective of this work was to demonstrate that copper silver selenide and TAGS could be segmented. The hot junction temperature was planned to be 725/sup 0/C with the segmentation temperature at 400/sup 0/C, both temperatures were selected to prevent excessive sublimation from the hot ends of the segments, respectively. The program was planned as a cooperative effort between General Atomic company and Teledyne Energy Systems. Accordingly, General Atomic synthesized the CuAgSe that was used to fabricate the test hardware that was ultimately delivered to General Atomic for testing. Both the CuAgSe and TAGS were hot pressed in an argon atmosphere then the segments were furnace-bonded to each other. A secondary objective was to produce CuAgSe powder by rapid solidification.

  18. 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...

  19. Synthesis and characterization of electrodeposited copper indium selenide and copper (indium, gallium) selenide thin films

    Microsoft Academic Search

    Robert Bonheur Friedfeld

    1999-01-01

    Electrodeposition is a cost effective method for growing polycrystalline thin films which is not limited by substrate\\/superstrate size and does not require the use of a vacuum. In this research, CuInSe2 and Cu(In,Ga)Se 2 polycrystalline thin films have been synthesized by electrodeposition. Both of these materials have very high absorption coefficients when compared to Si and GaAs, and can have

  20. Synthesis and characterization of electrodeposited copper indium selenide and copper (indium, gallium) selenide thin films

    NASA Astrophysics Data System (ADS)

    Friedfeld, Robert Bonheur

    Electrodeposition is a cost effective method for growing polycrystalline thin films which is not limited by substrate/superstrate size and does not require the use of a vacuum. In this research, CuInSe2 and Cu(In,Ga)Se 2 polycrystalline thin films have been synthesized by electrodeposition. Both of these materials have very high absorption coefficients when compared to Si and GaAs, and can have their band gaps adjusted through the control of their stoichiometries. Both CuInSe2 and Cu(In,Ga)Se2 are direct band gap semiconductors with the chalcopyrite crystal structure. Therefore, these materials are important for use in high efficiency photovoltaic solar cells. In an attempt to understand how the composition, morphology and crystallinity depend on electrodeposition conditions, various thin films of CuInSe2 and Cu(In,Ga)Se2 were grown by electrodeposition. These films were then characterized by a number of characterization techniques which include (1) scanning electron microscopy, (2) scanning tunneling microscopy, (3) energy dispersive spectroscopy, (4) X-ray diffraction, and (5) Auger electron spectroscopy. Results based on this research indicate two main conclusions. (1) Modulated or layered films of CuInSe2 can be grown by electrodeposition. Measurements made by Scanning Tunneling Microscopy of cleaved cross sections of the CuInSe2 layered films indicate the successful formation of layers. (2) Cu(In,Ga)Se2 thin films can be electrodeposited by a two-step process with minimal post treatment steps. The process developed here can be done at room temperature. Two electrochemical baths are used, one to electrodeposit a CuGa2 binary alloy, followed by the electrodeposition of a CuInSe2 thin film from another bath. The resulting bilayer film is then annealed in flowing argon at an elevated temperature to form the CIGS compound. Characterization results from measurements made by X-ray diffraction show that the resulting films maintain the basic chalcopyrite structure while the Bragg peaks shift to larger diffraction angles with increasing gallium content in the film. This is evidence to support the successful formation of CIGS films. This data is further corroborated by the energy dispersive spectroscopy and Auger electron spectroscopy data.

  1. Electron transport in lead selenide nanocrystal arrays

    E-print Network

    Schriver, Maria C

    2005-01-01

    I have investigated electrical properties of arrays of lead selenide (PbSe) nanocrystals (NC's) of approximately 6nm diameter. The films become substantially more conducting when annealed at 400K, although no chemical ...

  2. Crystal chemistry and self-lubricating properties of monochalcogenides gallium selenide and tin selenide

    SciTech Connect

    Erdemir, A.

    1993-02-01

    This paper describes the fundamentals of the crystal chemistry and self-lubricating mechanisms of two monochalcogenides; tin selenide and gallium selenide. Specifically, it enumerates their inter-atomic array and bond structure in crystalline states, and correlates this fundamental knowledge with their self-lubricating capacity. Friction tests assessing the self-lubricating performance of gallium and tin selenides were carried out on a pin-on-disk machine. Specifically, large crystalline pieces of gallium selenide and tin selenide were cut and cleaved into flat squares and subsequently rubbed against the sapphire balls. In another case, the fine powders (particle size {approx} 50--100 {mu}m) of gallium selenide and tin selenide were manually fed into the sliding interfaces of 440C pins and 440C disks. For the specific test conditions explored, it was found that the friction coefficients of the sapphire/gallium selenide and sapphire/tin selenide pairs were {approx} 0.23 and {approx} 0.35, respectively. The friction coefficients of 440C pin/440C disk test pairs with gallium selenide and tin selenide powders were on the orders of {approx} 0.22 and {approx} 0.38, respectively. For comparison, a number of parallel friction tests were performed with MoS{sub 2} powders and compacts and the results of these tests were also reported. The friction data together with the crystal-chemical knowledge and the electron microscopic evidence supported the conclusion that the lubricity and self-lubricating mechanisms of these solids are closely related to their crystal chemistry and the nature of interlayer bonding.

  3. Alloyed Copper Chalcogenide Nanoplatelets via Partial Cation Exchange Reactions

    PubMed Central

    2014-01-01

    We report the synthesis of alloyed quaternary and quinary nanocrystals based on copper chalcogenides, namely, copper zinc selenide–sulfide (CZSeS), copper tin selenide–sulfide (CTSeS), and copper zinc tin selenide–sulfide (CZTSeS) nanoplatelets (NPLs) (?20 nm wide) with tunable chemical composition. Our synthesis scheme consisted of two facile steps: i.e., the preparation of copper selenide–sulfide (Cu2–xSeyS1–y) platelet shaped nanocrystals via the colloidal route, followed by an in situ cation exchange reaction. During the latter step, the cation exchange proceeded through a partial replacement of copper ions by zinc or/and tin cations, yielding homogeneously alloyed nanocrystals with platelet shape. Overall, the chemical composition of the alloyed nanocrystals can easily be controlled by the amount of precursors that contain cations of interest (e.g., Zn, Sn) to be incorporated/alloyed. We have also optimized the reaction conditions that allow a complete preservation of the size, morphology, and crystal structure as that of the starting Cu2–xSeyS1–y NPLs. The alloyed NPLs were characterized by optical spectroscopy (UV–vis–NIR) and cyclic voltammetry (CV), which demonstrated tunability of their light absorption characteristics as well as their electrochemical band gaps. PMID:25050455

  4. Low cost copper indium gallium selenide by the FASST® process

    Microsoft Academic Search

    B. Sang; F. Adurodija; M. Taylor; A. Lim; J. Taylor; Y. Chang; S. McWilliams; R. Oswald; B. J. Stanbery; M. van Hest; J. Nekuda; A. Miedaner; C. Curtis; J. Leisch; D. Ginley

    2008-01-01

    Low cost manufacturing of Cu(In,Ga)Se2 (CIGS) films for high efficiency PV devices by the innovative Field-Assisted Simultaneous Synthesis and Transfer (FASST®) process is reported. The FASST® process is a two-stage reactive transfer printing method relying on chemical reaction between two separate precursor films to form CIGS, one deposited on the substrate and the other on a printing plate in the

  5. Indium selenides: structural characteristics, synthesis and their thermoelectric performances.

    PubMed

    Han, Guang; Chen, Zhi-Gang; Drennan, John; Zou, Jin

    2014-07-23

    Indium selenides have attracted extensive attention in high-efficiency thermoelectrics for waste heat energy conversion due to their extraordinary and tunable electrical and thermal properties. This Review aims to provide a thorough summary of the structural characteristics (e.g. crystal structures, phase transformations, and structural vacancies) and synthetic methods (e.g. bulk materials, thin films, and nanostructures) of various indium selenides, and then summarize the recent progress on exploring indium selenides as high-efficiency thermoelectric materials. By highlighting challenges and opportunities in the end, this Review intends to shine some light on the possible approaches for thermoelectric performance enhancement of indium selenides, which should open up an opportunity for applying indium selenides in the next-generation thermoelectric devices. PMID:24729463

  6. The electrochemical oxidation of organic selenides and selenoxides

    SciTech Connect

    Ryan, M.D.; Yau, J.; Hack, M. [Marquette Univ., Milwaukee, WI (United States). Dept. of Chemistry

    1997-06-01

    The electrochemical oxidation of alkyl and aryl selenides was investigated in acetonitrile. The oxidation of diphenyl selenide and di(4-methylphenyl) selenide led primarily to the formation of their respective selenoxides, which were identified by exhaustive coulometric oxidation and {sup 1}H and {sup 13}C analysis of the products. The selenoxide itself was not observed in the cyclic voltammetry of the selenide for two reasons: first, the protonation of the selenoxide by the acid formed from the reaction of water with the cation radical and second, the formation of a selenoxide hydrate. The formation of the hydrate with diphenyl selenoxide was verified by isolation of the dimethoxy derivative. In addition to the selenoxide, selenonium compounds, formed by the coupling of the oxidized material, were also observed. The alkyl selenides were generally oxidized at a lower potential than the aryl selenides. This trend is different from the sulfur analogues, where the aryl sulfides are easier to oxidize than their alkyl counterparts. As a result, the difference in their redox potentials is relatively small. These differences may occur because the oxidation of aryl sulfides is more likely to take place on the aromatic ring, which leads to a greater yield of the coupled products (about 100%) when compared to the selenide analogue.

  7. Cuprous selenide and sulfide form improved photovoltaic barriers

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Photovoltaic barriers formed by depositing a layer of polycrystalline cuprous sulfide or cuprous selenide on gallium arsenide are chemically and electrically stable. The stability of these barrier materials is significantly greater than that of cuprous iodide.

  8. The Diorganoselenium and Selenides Compounds Electrochemistry

    PubMed Central

    Tepecik, Abdulkadir; Altin, Zehra; Erturan, Seyfettin

    2008-01-01

    The electrochemical behavior of Ar2SeCl2, and Ar2Se2, (Ar:CH3OC6H5; C2H5OC6H5) in acetonitrile (AN) containing tetrabutylammonium tetrafluoroborat (TBAFB) as supporting electrolyte was studied on a stationary electrode (spe). In order to elucidate the electrode reactions linear potential scan, cyclic voltammetry and controlled-potential coulometry were employed using a platinum electrode. It is shown that Ar2SeCl2 and Ar2Se2 are reduced and oxidized to Ar2Se, Ar2Se2Ar2, Se, and Ar2Se(BF4)2. It is generally accepted that as final electrochemical reduction products, the corresponding Ar2Se, Ar4Se2, and Se were formed. The disappearance of the diorganoselenium and selenide in the course of the coulometric experiments was validated by measuring the limiting current of the voltammetric waves at spe and UV spectrometry. PMID:19255626

  9. Synthesis and high temperature transport properties of new quaternary layered selenide NaCuMnSe{sub 2}

    SciTech Connect

    Pavan Kumar, V.; Varadaraju, U.V., E-mail: varada@iitm.ac.in

    2014-04-01

    Synthesis and high temperature transport properties of NaCu{sub 1+x}Mn{sub 1?x}Se{sub 2}, (x=0?0.75) a new quaternary layered selenide, are reported. NaCuMnSe{sub 2} crystallizes in a trigonal unit cell with space group of P-3m1 (a=4.1276 Å, c=7.1253 Å). The isovalent substitution of Mn{sup 2+} by Cu{sup 2+} is carried out. All the compositions show semiconducting nature, whereas the Seebeck coefficient increases gradually over the entire measured temperature range. Compositions with x=0 and 0.025 follow thermally activated behavior. With increase in copper concentration the conduction mechanism transforms to 2D variable range hopping (VRH) for x=0.05 and 0.075. - Graphical abstract: Crystal structure of NaCuMnSe{sub 2}. - Highlights: • A new quaternary layered selenide NaCuMnSe{sub 2} is synthesized. • All the compositions show semiconducting nature, whereas the Seebeck coefficient increases gradually over the entire measured temperature range. • Conduction mechanism transforms from thermally activated behavior to 2D variable range hopping with increase in copper concentration.

  10. Colloquium: The unexpected properties of alkali metal iron selenide superconductors

    E-print Network

    Tennessee, University of

    20 May 2013) The iron-based superconductors that contain FeAs layers as the fundamental building in a single layer of FeSe. The conceptual issues considered established for the alkali metal iron selenides of these iron-based superconductors, just as the CuO2 layers are the crucial ingredients of the famous high

  11. Optical properties and electronic structures of copper indium gallium selenide: Effect of copper deficiency

    NASA Astrophysics Data System (ADS)

    Han, Sung-Ho

    In this thesis, I describe basic research done to understand the optical properties and electronic structure of polycrystalline thin-film CuIn 1-xGaxSe 2 (CIGS) used for high efficiency photovoltaic (PV) solar cells. The effect of Cu deficiency on CIGS material properties has been intensively studied. The physics of p-n junctions and their application to photovoltaic solar cells are thoroughly discussed in Chap. 1. Chapter 2 presents a general knowledge of CIGS materials in terms of crystal structure, phase, electronic structure, intrinsic defects, and growth and characterization methods. Chapter 3 covers the physics of spectroscopic ellipsometry in detail, especially for Maxwell's equations, polarization of light waves, Fresnel equations, and the fundamental equation of ellipsometry. The method used to determine the optical constants from ellipsometric parameters is introduced using an easily understandable example, SiO2 on Si. Chapter 4 present the results of extensive studies of the effect of Cu deficiency on the properties of CuInSe2 (CIS). Phase transitions, optical properties and the electronic structure are discussed for Cu-poor CIS. Probing defect levels in the sub-bandgap region of CIS was successful using spectroscopic ellipsometry and the results are compared with first-principles calculations and data from the literature. In the next chapter, general behaviors of the optical properties of CuIn1-xGa xSe2 are introduced. Similar schemes are used to study the effect of Cu deficiency on CuIn0.8Ga0.2Se 2 and CuIn0.6Ga0.4Se2 as that on CIS. The effect of Cu deficiency on the optical bowing coefficients has been explained. The maximum efficiency of laboratory thin-film polycrystalline CIGS solar cells exceeds their single-crystal counterparts. This has been explained in terms of Cu deficiency in CIGS. Our studies of the effect of Cu deficiency have provided the first experimental evidence in support of this hypothesis. We find that there is a reduction in the absorption strength in the spectral range of 1-3 eV determined by spectroscopic ellipsometry. This reduction can be explained in terms of the removal of Cu 3d density of states near valence band maximum (VBM) for Cu-poor CIGS. The properties of a distinct surface layer on CIGS are determined using spectroscopic ellipsometry. We found that Cu is more deficient at surface than in the bulk region of the surface using spectroscopic ellipsometry. These results have important implications for the functioning of polycrystalline photovoltaic devices. The grain boundary (GB) region can be thought as interior surface and is expected to be more Cu deficient than the grain interior (GI) region. In addition, GBs tend to getter defects and impurities during the high-temperature processing used to produce thin-film PX-CIGS. Cu vacancies create a barrier for holes through the reduced DOS at the VBM. Because the GB tends to exclude majority carrier holes, it effectively impedes electron-hole recombination. The combination of gettering defects that cause fast non-radiative recombination with the carrier-separating effects of the GB band structure serve to greatly enhance the efficiency of thin-film PX-CIGS PV devices. Such a GB filter can be a key to the utilization of polycrystalline semiconductors in transport devices.

  12. Optical properties and electronic structures of copper indium gallium selenide: Effect of copper deficiency

    Microsoft Academic Search

    Sung-Ho Han

    2005-01-01

    In this thesis, I describe basic research done to understand the optical properties and electronic structure of polycrystalline thin-film CuIn 1-xGaxSe 2 (CIGS) used for high efficiency photovoltaic (PV) solar cells. The effect of Cu deficiency on CIGS material properties has been intensively studied. The physics of p-n junctions and their application to photovoltaic solar cells are thoroughly discussed in

  13. Characterization of zinc selenide single crystals

    NASA Technical Reports Server (NTRS)

    Gerhardt, Rosario A.

    1996-01-01

    ZnSe single crystals of high quality and low impurity levels are desired for use as substrates in optoelectronic devices. This is especially true when the device requires the formation of homoepitaxial layers. While ZnSe is commercially available, it is at present extremely expensive due to the difficulty of growing single crystal boules with low impurity content and the resultant low yields. Many researchers have found it necessary to heat treat the crystals in liquid Zn in order to remove the impurities, lower the resistivity and activate the photoluminescence at room temperature. The physical vapor transport method (PVT) has been successfully used at MSFC to grow many single crystals of II-VI semiconducting materials including ZnSe. The main goal at NASA has been to try to establish the effect of gravity on the growth parameters. To this effect, crystals have been grown vertically upwards or horizontally. Both (111) and (110) oriented ZnSe crystals have been obtained via unseeded PVT growth. Preliminary characterization of the horizontally grown crystals has revealed that Cu is a major impurity and that the low temperature photoluminescence spectra is dominated by the copper peak. The ratio of the copper peak to the free exciton peak is being used to determine variations in composition throughout the crystal. It was the intent of this project to map the copper composition of various crystals via photoluminescence first, then measure their electrical resistivity and capacitance as a function of frequency before proceeding with a heat treatment designed to remove the copper impurities. However, equipment difficulties with the photoluminescence set up, having to establish a procedure for measuring the electrical properties of the as-grown crystals and time limitations made us re-evaluate the project goals. Vertically grown samples designated as ZnSe-25 were chosen to be measured electrically since they were not expected to show as much variation in their composition through their cross-section as the horizontally grown samples.

  14. Cold pressed cadmium selenide photoanodes for electrochemical solar cells

    Microsoft Academic Search

    A. Mackintosh; S. Wessel; F. El Guibaly; K. Colbow

    1983-01-01

    Cold pressing of cadmium selenide powder was investigated as a technique for producing photoanodes for electrochemical solar cells. Physical properties such as density, resistivity and surface morphology were determined and related to solar cell performance via wavelength response, quantum efficiency and white light current-voltage characteristics. The spectral response indicated a bandgap of 1.7 eV. Pellets pressed at higher pressure showed

  15. Chemical deposition of thin films of lead selenide 

    E-print Network

    Skovlin, Dean Oliver

    1956-01-01

    -Sulfite Solutions. 15 9. Conditions for Reproducibility of PbSe Deposi. tion. 20 A. Procedure. 20 10. Reaction Rate as a Function of Sodium Citrate Concentration . . . , . . . . . , . . . . . . 21 11. Study of Film Resistance as a Function of DMS... deposit furnishes the nuclei which act as a seeding layer for tbe growth of microcrystalline lead selenide. The lead sulfide layer is prepared by immersion of the surface to be coated for a short time in a bath of lead acetate and thiourea, which...

  16. Thermoelectric properties of alloys based on gadolinium selenides

    Microsoft Academic Search

    Yu. M. Goryachev; V. A. Obolonchik; T. M. Mikhlina; T. M. Yarmola

    1982-01-01

    The gadolinium selenide GdSe1.3 and its alloys are strongly degenerate semimetals of the n-type. These systems can provide a basis for the development of potentially useful thermoelectric materials. Electrotransport in the alloys investigated is effected by electrons in at least two subzones, a strongly degenerate and a weekly degenerate one. Substitution of tantalum and rhenium for gadolinium changes both the

  17. Electron beam assisted synthesis of cadmium selenide nanomaterials

    SciTech Connect

    Rath, M. C.; Guleria, A.; Singh, S.; Singh, A. K.; Adhikari, S.; Sarkar, S. K. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2013-02-05

    Cadmium selenide nanomaterials of various shapes and sizes have been synthesized in different condensed media through electron beam irradiation using a 7 MeV linear accelerator. The microstructures in different media as well as the presence of capping reagents play a crucial role in the formation of nanomaterials of different shapes and sizes. Their optical properties could be efficiently tuned by controlling the synthetic parameters.

  18. The unexpected properties of alkali metal iron selenide superconductors

    SciTech Connect

    Dagotto, Elbio R [ORNL

    2013-01-01

    The iron-based superconductors that contain FeAs layers as the fundamental building block in the crystal structures have been rationalized in the past using ideas based on the Fermi surface nesting of hole and electron pockets when in the presence of weak Hubbard U interactions. This approach seemed appropriate considering the small values of the magnetic moments in the parent compounds and the clear evidence based on photoemission experiments of the required electron and hole pockets. However, recent results in the context of alkali metal iron selenides, with generic chemical composition AxFe2ySe2 (A alkali metal element), have challenged those previous ideas since at particular compositions y the low-temperature ground states are insulating and display antiferromagnetic order with large iron magnetic moments. Moreover, angle-resolved photoemission studies have revealed the absence of hole pockets at the Fermi level in these materials. The present status of this exciting area of research, with the potential to alter conceptually our understanding of the ironbased superconductors, is here reviewed, covering both experimental and theoretical investigations. Other recent related developments are also briefly reviewed, such as the study of selenide two-leg ladders and the discovery of superconductivity in a single layer of FeSe. The conceptual issues considered established for the alkali metal iron selenides, as well as several issues that still require further work, are discussed.

  19. New quinternary selenides: Syntheses, characterizations, and electronic structure calculations

    SciTech Connect

    Chung, Ming-Yan; Lee, Chi-Shen, E-mail: chishen@mail.nctu.edu.tw

    2013-06-01

    Five quinternary selenides, Sr?.??Y?.??Ge?.??Sb?.??Se? (I), Sr?.??La?.??Ge?.??Sb?.??Se? (II), Sr?.??La?.??Sn?.??Bi?.??Se? (III), Ba?.?? La?.?? Sn?.??Sb?.??Se? (IV), and Ba?.?? La?.??Sn?.??Bi?.??Se? (V), were synthesized by solid-state reaction in fused silica tubes. These compounds are isostructural and crystallize in the Sr?GeSb?Se? structural-type, which belongs to the orthorhombic space group Pnma (no. 62). Three structural units, 1?[MSe?], 1?[M?Se??] (M=Tt, Pn) and M´ (M´=groups II and III element), comprise the entire one-dimensional structure, separated by M´. Measurements of electronic resistivity and diffused reflectance suggest that IV and V have semiconducting properties. Electronic structure calculations confirm the site preferences of Sr/La element discovered by crystal structure refinement. - Graphical abstract: Quinternary selenides Ae?.??M?.??Tt?.??Pn?.??Se? (Ae, M, Tt, Pn=Sr/Ba, Y/La, Ge/Sn, Sb/Bi) were synthesized and their site preferences were characterized by single-crystal X-ray diffraction and electronic structure calculation. Highlights: • Five new quinternary selenides were synthesized and characterized. • Structural units, 1?[MSe?] and 1?[M?Se??] (M=Tt, Pn), construct the one-dimensional structure. • Calculations of electronic structure confirm site preference of Sr/La sites.

  20. Formation of Lead Selenide Crystallites in a Dielectric Matrix of Lead Selenite

    Microsoft Academic Search

    V. V. Tomaev; L. L. Makarov; P. A. Tikhonov; V. P. Popov; I. V. Rozhdestvenskaya

    2005-01-01

    The interaction of oxygen with solid lead selenide samples prepared in the form of bulk single crystals, films, pressed pellets, and powders is investigated in the temperature range 298–823 K at exposure times of 5–240 min and an oxygen pressure of ?105 Pa. All samples are produced from a lead selenide batch heat treated under dynamic vacuum. It is revealed

  1. Synthesis and characterisation of Copper Zinc Tin Sulphide (CZTS) compound for absorber material in solar-cells

    Microsoft Academic Search

    Vipul Kheraj; K. K. Patel; S. J. Patel

    2013-01-01

    The development of thin-film semiconductor compounds, such as Copper Indium Gallium Selenide (CIGS), has caused remarkable progress in the field of thin-film photovoltaics. However, the scarcity and the increasing prices of indium impose the hunt for alternative materials. The Copper Zinc Tin Sulphide (CZTS) is one of the promising emerging materials with Kesterite-type crystal structure and favourable material properties like

  2. Structural organization of As-rich selenide glasses

    NASA Astrophysics Data System (ADS)

    Golovchak, R.; Kovalskiy, A.; Shpotyuk, O.; Jain, H.

    2013-07-01

    The structure of bulk AsxSe100-x (40?x?55) glasses, prepared by conventional melt-quenching method, is investigated using high-resolution XPS. The moieties of constituting structural fragments are evaluated and compared to those determined from the "chain-crossing" model. Significant deviations from this model are observed for x=50 and x=55 compositions. In glasses with concentration of As higher than 50 at% the tendency to As segregation and formation of Se-Se bonds is demonstrated. Deviations from "8-N" rule are not found in the structure of the investigated As-rich selenide glasses.

  3. Cadmium sulfide/copper selenide cell research copper selenide-based thin film solar cells. Second quarterly technical progress report, September 1, 1980-December 1, 1980

    SciTech Connect

    Sauve', S.P.; Mickelsen, R.A.; Stewart, J.M.; Chen, W.S.

    1980-01-01

    The objective of this program is to investigate the use of Cu/sub 2-x/Se to produce low cost, high efficiency photovoltaic solar cells. The Cu/sub 2-x/Se films are produced by coevaporation of Cu and Se from separate, individually controlled vapor sources onto heated glass substrates. This method gives greater composition controllability and is readily adaptable to large scale production efforts. Two quartz crystal microbalances are used to separately monitor the Cu and Se deposition rates. The structural, electrical, and optical properties of the Cu/sub 2-x/Se films have been measured for deposits made on 250/sup 0/C substrates. The optical absorption measurements show the material having an indirect band gap of 1.4 eV and a direct gap of 2.2 eV. These values are for stoichiometric indices in the range of 0.17 less than or equal to x less than or equal to 0.26. Hall and conductivity measurements give hole mobilities in the range of 3 to 7 cm/sup 2//Vsec and hole densities of the order of 4 x 10/sup 22/ cm/sup -3/. For deposits made on substrate at 160/sup 0/C, the mobility is in the range of 3 to 10 cm/sup 2//Vsec and hole densities on the order of 10/sup 18/ to 10/sup 21/ cm/sup -3/ for 0.1 less than or equal to x less than or equal to 0.3. To date, the best cell has photovoltaic characteristics of J/sub sc/ = 11.6 mA/cm/sup 2/, V/sub oc/ = 460 mV, F.F. = 0.62 and eta = 3.3% when tested under simulated AM1 illumination. In an effort to improve cell performance, low resistance CdS was used. Cell performance degraded considerably with the low resistance CdS resulting in substantially lower values for both V/sub oc/ and I/sub sc/. It is believed in part that this difficulty can be traced to pinhole defects in the ITO electrode. When the low resistance CdS is deposited on ITO, regions in the CdS appear to be high in Cd where pinholes in the ITO were observed.

  4. Fractal simulation of the resistivity and capacitance of arsenic selenide

    SciTech Connect

    Balkhanov, V. K., E-mail: ballar@yandex.ru; Bashkuev, Yu. B. [Russian Academy of Sciences, Division of Physical Problems, Buryat Scientific Center, Siberian Branch (Russian Federation)

    2010-03-15

    The temperature dependences of the ac resistivity R and ac capacitance C of arsenic selenide were measured more than four decades ago [V. I. Kruglov and L. P. Strakhov, in Problems of Solid State Electronics, Vol. 2 (Leningrad Univ., Leningrad, 1968)]. According to these measurements, the frequency dependences are R {proportional_to} {omega}{sup -0.80{+-}0.01} and {Delta}C {proportional_to} {omega}{sup -0.120{+-}0.006} ({omega} is the circular frequency and {Delta}C is measured from the temperature-independent value C{sub 0}). According to fractal-geometry methods, R {proportional_to} {omega}{sup 1-3/h} and {Delta}C {proportional_to} {omega}{sup -2+3/h}, where h is the walk dimension of the electric current in arsenic selenide. Comparison of the experimental and theoretical results indicates that the walk dimensions calculated from the frequency dependences of resistivity and capacitance are h{sub R} = 1.67 {+-} 0.02 and h{sub C} = 1.60 {+-} 0.08, which are in agreement with each other within the measurement errors. The fractal dimension of the distribution of conducting sections is D = 1/h = 0.6. Since D < 1, the conducting sections are spatially separated and form a Cantor set.

  5. Chromium-doped zinc selenide gain media: From synthesis to pulsed mid-infrared laser operation

    E-print Network

    Demirbas, Umit

    This paper provides an overview of the experimental work performed in our research group on the synthesis, spectroscopic investigation, and laser characterization of chromium-doped zinc selenide (Cr[superscript 2+]:ZnSe). ...

  6. Novel synthesis of silver selenide nano-powder from silver nitrate and organo-selenium compound

    Microsoft Academic Search

    P. K. Khanna; B. K. Das

    2004-01-01

    Silver selenide nano-powder has been prepared, by use of cycloalkeno-1,2,3-selenadiazole, an organic compound that releases highly reactive form of selenium upon thermolysis. The simple and one-step preparation can be considered a green synthesis. Powder X-ray diffraction pattern revealed that the pure beta silver selenide (?-Ag2Se) is formed and analysis suggests that the particles are much smaller than the bulk powder

  7. Growth of zinc selenide crystals by physical vapor transport in microgravity

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz

    1995-01-01

    The growth of single crystals of zinc selenide was carried out by both closed ampoule physical vapor transport and effusive ampoule physical vapor transport (EAPVT). The latter technique was shown to be a much more efficient method for the seeded growth of zinc selenide, resulting in higher transport rates. Furthermore, EAPVT work on CdTe has shown that growth onto /n11/ seeds is advantageous for obtaining reduced twinning and defect densities in II-VI sphalerite materials.

  8. A microwave spectroscopic study of the reaction of cyanogen bromide and hydrogen selenide 

    E-print Network

    Gardner, John Berten

    1958-01-01

    UBRARy A 4 At COLLEGE OF TEXAS A MICROWAVE SPECTROSCOPIC STUDY OF THE REACTION OF CYANOGEN BROMIDE AND HYDROGEN SELENIDE A Thesis By Johnny Berten Gardner Submitted to the Graduate School of The Agricultural and Mechanical College of Texas... in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1958 Major Subject: Chemistry A MICROWAVE SPECTROSCOPIC STUDY OF THE REACTION OF CYANOGEN BROMIDE AND HYDROGEN SELENIDE A Thesis By Johnny Berten Gardner Approved...

  9. Physicochemical properties of dimethyl selenide and dimethyl diselenide

    SciTech Connect

    Karlson, U. (National Environmental Research Inst., Roskilde, DE (United States). Dept. of Marine Ecology and Microbiology); Frankenberger, W.T. Jr. (Univ. of California, Riverside, CA (United States). Dept. of Soil and Environmental Sciences); Spencer, W.F. (Univ. of California, Riverside, CA (United States). Dept. of Soil and Environmental Sciences)

    1994-07-01

    Volatilization of selenium (Se) is a dissipation mechanism by which gaseous Se is redistributed in the environment. The vapor pressures of dimethyl selenide (DMSe) and dimethyl diselenide (DMDSe) were determined using the isoteniscope method, and the solubility of DMSe in H[sub 2]O was determined in a closed system by headspace analysis. The vapor pressure at 25 C were 32.03 and 0.38 kPa for DMSe and DMDSe, respectively. The enthalpies of vaporization were calculated as 31.90 and 74.92 kJ mol[sup [minus]1], respectively. The solubility of DMSe was 0.0244 g/g of H[sub 2]O. The Henry's law constant for DMSe was calculated as 143 kPa kg mol[sup [minus]1] (0.144 kPa m[sup 3] mol[sup [minus]1]).

  10. Thermal lensing in silver gallium selenide parametric oscillator crystals.

    PubMed

    Marquardt, C L; Cooper, D G; Budni, P A; Knights, M G; Schepler, K L; Dedomenico, R; Catella, G C

    1994-05-20

    We performed an experimental investigation of thermal lensing in silver gallium selenide (AgGaSe(2)) optical parametric oscillator crystals pumped by a 2-µm laser at ambient temperature. We determined an empirical expression for the effective thermal focusing power in terms of the pump power, beam diameter, crystal length, and absorption coefficient. This relation may be used to estimate average power limitations in designing AgGaSe(2) optical parametric oscillators. We also demonstrated an 18% slope efficiency from a 2-µm pumped AgGaSe(2) optical parametric oscillator operated at 77 K, at which temperature thermal lensing is substantially reduced because of an increase in the thermal conductivity and a decrease in the thermal index gradient dn/dT. Cryogenic cooling may provide an additional option for scaling up the average power capability of a 2-µm pumped AgGaSe(2) optical parametric oscillator. PMID:20885687

  11. Synthesis and characterization of luminescent aluminium selenide nanocrystals

    SciTech Connect

    Balitskii, O.A., E-mail: balitskii@electronics.wups.lviv.ua [Department of Electronics, Lviv Ivan Franko National University, Dragomanov Str., 50, 79005 Lviv (Ukraine); Demchenko, P.Yu. [Department of Chemistry, Lviv Ivan Franko National University, Kyryla and Mefodiya 6, 79005 Lviv (Ukraine)] [Department of Chemistry, Lviv Ivan Franko National University, Kyryla and Mefodiya 6, 79005 Lviv (Ukraine); Mijowska, E.; Cendrowski, K. [Centre of Knowledge Based Nanomaterials and Technologies, Institute of Chemical and Environmental Engineering, West Pomeranian University of Technology, 10, Pulaskiego Str., Szczecin 70-322 (Poland)] [Centre of Knowledge Based Nanomaterials and Technologies, Institute of Chemical and Environmental Engineering, West Pomeranian University of Technology, 10, Pulaskiego Str., Szczecin 70-322 (Poland)

    2013-02-15

    Highlights: ? Synthesis procedure of size and sharp controlled Al{sub 2}Se{sub 3} nanocrystals is introduced. ? Obtained nanoparticles are highly crystalline of hexagonal wurtzite type. ? Colloidal Al{sub 2}Se{sub 3} nanocrystals are highly luminescent in the near UV spectral region. ? They can be implemented in light emitters/collectors, concurring with II–VI nanodots. -- Abstract: We propose the synthesis and characterization of colloidal aluminium selenide nanocrystals using trioctylphosphine as a solvent. The nanoparticles have several absorption bands in the spectral region 330–410 nm and are bright UV-blue luminescent, which is well demanded in light collecting and emitting devices, e.g. for tuning their spectral characteristics to higher energy solar photons.

  12. Studies of compounds related to copper indium gallium selenide solar cells

    Microsoft Academic Search

    Haiping Wang

    2002-01-01

    Crystals of Cu(In1-xGax)3Se 5 were grown by the horizontal and vertical Bridgman methods. A non-contact carbon coating was used to avoid the adhesion between Cu(In1-x Gax)3Se5 ingots and the inner ampoule walls. The composition along and across the as grown ingots with different starting Ga contents was analyzed and the results were interpreted by the established pseudobinary phase diagrams. Results

  13. {112} Polar surfaces of copper(indium,gallium)selenide: Properties and effects on crystal growth

    Microsoft Academic Search

    Dongxiang Liao

    2003-01-01

    Cu(In,Ga)Se2 (GIGS) are promising materials for thin film photovoltaic applications. This work studies the epitaxial growth of CIGS single crystal films on GaAs substrates of various orientations and characterizes the properties of the thin films. A surprising finding is the strong tendency of film surfaces to facet to {112} planes. The work attempted to establish the connections between the film

  14. Long-term performance analysis of copper indium gallium selenide thin-film photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Kaul, Ashwani; Pethe, Shirish A.; Dhere, Neelkanth G.

    2012-01-01

    Current accelerated qualification tests of photovoltaic (PV) modules mostly assist in avoiding premature failures but can neither duplicate changes occurring in the field nor predict useful product lifetime. Therefore, outdoor monitoring of field-deployed thin-film PV modules was undertaken at FSEC with the goal of assessing their performance in hot and humid climate under high system-voltage operation. Significant and comparable degradation rate of -5.13±1.53% and -4.5±1.46% per year was found using PVUSA type regression analysis for the positive and negative strings, respectively of 40W glass-to-glass Cu-In-Ga-Se (CIGS) thin-film PV modules in the hot and humid climate of Florida. Using the current-voltage measurements, it was found that the performance degradation within the PV array was mainly due to a few (8% to 12%) modules that had substantially higher degradation. The remaining modules within the array continued to show reasonable performance (>96% of the rated power after ˜ four years).

  15. Impact of secondary barriers on copper-indium-gallium-selenide solar-cell operation

    NASA Astrophysics Data System (ADS)

    Pudov, Alexei O.

    Thin-film solar cells based on CuInSe2 (CIS) absorber with a band gap of Eg = 1.0 eV and also based on CuIn1-x GaxSe2 (CIGS) alloy absorbers with a band-gap range of Eg = 1.0--1.67 eV are investigated in this work. Intermediate "buffer" semiconductor layers in p-n junctions of CIGS solar cells often improve photodiode properties of the devices. The primary goal of the thesis is to study secondary barriers in the conduction band at the buffer/absorber interface, which may limit current transport and thus reduce the efficiency of the solar cells. The secondary goal is to explore alternative wide-bandgap buffers in CIGS cell structures. CIGS cells with standard CdS buffer layers, and alternative ZnS(O,OH) and InS(O,OH) buffer layers were studied. CdS/CuIn1-xGaxSe2 solar cells with variable Ga content have a range of conduction-band offsets (DeltaEc) in the junction from moderately positive (spike offsets) in CdS/CuInSe2 to moderately negative (cliff offsets) in CdS/CuGaSe 2. Moderate conduction-band spikes in CdS/CIS and low-Ga CdS/CIGS are expected to cause distortions in diode current-voltage (J-V) curves of such solar cells under "red" illumination (hnu < Eg(buffer)); no J-V distortions are expected for high-Ga CdS/CIGS with cliff offsets. These predictions were confirmed in experiments: the distortions were absent for cells with Eg above 1.2--1.3 eV, at which CdS/CIGS DeltaE c is near zero. Experiments and numerical simulations showed that one approach to reduce secondary barriers and J-V distortions in low-Ga high-spike cells is to thin the buffer layer(s). Blue photons (hnu above Eg(buffer)) in the solar spectrum induce photoconductivity in the otherwise compensated buffers, which also results in lowering of the secondary barriers. It was shown that CIGS cells with CdS, InS(O,OH), and ZnS(O,OH) buffers have a similar response to "blue" photons: J-V distortion, if present under red light, is reduced or entirely disappears with blue-light exposure within minutes. The distortion re-appearance without blue light is the order of a thousand times slower. Using wider-gap buffers, such as InS(O,OH) and ZnS(O,OH), was shown to produce higher photocurrents in solar cells. This photocurrent improvement is a central direction in the effort of further increasing efficiencies of thin-film solar cells.

  16. Studies of compounds related to copper indium gallium selenide solar cells

    NASA Astrophysics Data System (ADS)

    Wang, Haiping

    Crystals of Cu(In1-xGax)3Se 5 were grown by the horizontal and vertical Bridgman methods. A non-contact carbon coating was used to avoid the adhesion between Cu(In1-x Gax)3Se5 ingots and the inner ampoule walls. The composition along and across the as grown ingots with different starting Ga contents was analyzed and the results were interpreted by the established pseudobinary phase diagrams. Results of XRD confirmed that the lattice constants of the Cu(In1-xGax)3Se 5 crystals varied linearly with the Ga content. Results of X-ray Laue back-reflection showed that the Cu(In1-xGax) 3Se5 ingots contained large single crystal regions. Hall effect measurements carried out on the grown samples revealed that the Cu(In 1-xGax)3Se5 crystals were highly resistive with rather low carrier concentrations. The morphology of as-grown or cleaved sample surfaces of the Cu(In1-xGax) 3Se5 ingots were also studied under optical microscope and SEM. Metallic Na was, for the first time, introduced into Cu(In1-x Gax)3Se5 compounds to observe the doping effects. The introduction of Na increased the electron concentration significantly for CuIn3Se5 samples (x = 0) but did not show a significant effect on Cu(In1-xGax) 3Se5 samples with x > 0. The increase in electron concentration in the CuIn3Se5 samples after the Na diffusion could be explained by defect generation related to Se and In sites. Crystals of CuInSe2 were also grown by the horizontal Bridgman method for the first time with the addition of metallic sodium. Degradation in crystalline quality and a change of conductivity type from p- to n-type were observed in ingots grown from melts containing more than 0.25 at. % Na. Experiments of Na diffusion were also carried out on CuInSe 2 crystals in a sealed glass ampoule to observe the doping effect. Hot probe measurements indicated that the sodium-treated CuInSe2 samples changed from p-type to n-type. MIS devices were fabricated on the Na-treated CuIn3Se 5 material for electrical characterization. Dark current density-voltage characteristics and differential capacitance-voltage characteristics of the MIS devices were measured at room temperature. An energy band diagram of the MIS devices has been constructed based on the band lineup data reported in the literature. The current transport mechanism was examined and a dominant multi-step tunneling process was proposed. Samples of Cu(In1-xGax)3Se 5 with x ? 0.5 were found to be strongly photoconductive over the wavelength range from 700 to 1100 nm even at room temperature. It was observed that the sensitivity of photoconductivity was greatly influenced by surface preparation conditions. Chemically etched samples showed the highest photoconductivity, believed to be due to the reduced surface recombination velocity. Capacitance measurements were carried out to investigate the interface and bulk properties of ZnO/CdS/Cu(In1-xGax)Se 2 solar cells. Results from the steady state C-V measurements showed evidence of interface or surface states, especially for the samples without annealing. DLTS technique was used to determine the deep levels in Cu(In 1-xGax)Se2 crystals with Ga content varying from 0 to 1. Different deep levels for holes with different DLTS spectra were found in the Cu(In1-xGax)Se2 crystals, with different Ga contents. The present results showed that the Ga content has an important effect on the formation of deep levels in Cu(In1-x Gax)Se2 crystals.

  17. Device physics of copper(indium,gallium)selenide(2) thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Gloeckler, Markus

    2005-11-01

    Thin-film solar cells have the potential to be an important contributor to the global energy demand by the mid-21st-century. Cu(In,Ga)Se 2 (CIGS) solar cells, which have achieved laboratory efficiencies close to 20%, are highly attractive, because their band gap is near the optimal value, their polycrystallinity is not significantly detrimental to their performance, and the broad choice of heterojunction partners available allows additional degrees of freedom for optimizing their performance. Although steady progress has been made for CIGS solar cells, this progress has largely been driven by empirical optimization rather than by in-depth understanding of appropriate physical models. This thesis is intended to fill some of the gaps that exist between state-of-the-art experimental solar cells and their device physics. The level of complexity involved is largely prohibitive to analytical treatment and, hence, numerical approaches are primarily utilized. The dominant topics for CIGS solar cells covered in this dissertation are (1) variation in the Ga/(Ga+In) stoichiometry ("grading"), (2) the formation of "good" heterojunctions, (3) photoconductive effects in window or buffer materials, (4) the apparently benign or even beneficial presence of grain-boundaries (GBs), including a discussion of charged GBs and the effects of Cu-depletion near GBs. This work establishes a baseline model for CIGS solar cells and, from this starting point, the device physics relating to these questions is discussed and principles are identified that apply to a broad range of devices. CIGS grading is shown to have only small potential to improve device performance. This conclusion conflicts with earlier studies, and it is shown that the difference arises in the evaluation of the grading benefit, in particular, the proper choice of the reference performance. Band-gap increases toward the front of the device are most likely detrimental, while band-gap increases toward the back can be modestly beneficial. The popular "double grading" approach achieves only very small additional gains over the simple back grading approach. Very thin-absorber cells can benefit substantially from back grading, because in this case, grading can mitigate detrimental back-contact surface recombination. The window/absorber interface is studied and, in good agreement with experiments, a limitation of the open-circuit voltage is observed for wide-band-gap CdS/CIGS solar cells. (Abstract shortened by UMI.)

  18. New deposition process of copper(indium, gallium) selenide thin films for solar cell applications

    NASA Astrophysics Data System (ADS)

    Khatri, Himal

    Molybdenum (Mo) is currently the most common material used for Cu(In,Ga)Se 2 solar cell back contacts. The first objective of this study is to utilize in--situ and ex--situ characterization techniques to investigate the growth, as well as the physical and chemical properties, of Mo thin films deposited by RF magnetron sputtering onto soda-- lime glass (SLG) substrates. The effects of the deposition pressure on the nucleation and growth mechanisms that ultimately influence morphology and grain structure have been studied. Correspondence between real time spectroscopic ellipsometry (RTSE), X--ray diffraction (XRD), atomic force microscopy (AFM), and four--point probe resistivity measurements indicate that increasing deposition pressure leads to smaller average grain sizes and higher oxygen content in the Mo thin films. Changes of the material properties were also evaluated by changing RF power. It is observed that higher RF power, results in higher conductivity films. The second and overall objective of this work is to focus on the deposition and characterization of the Cu(In,Ga)Se2 absorber layer using the hybrid co--sputtering and evaporation process, which has potential for commercial PV. Solar cells were completed with a range of elemental compositions in the absorber layer, keeping a constant profile of Ga and varying Cu concentrations. The slightly Cu deficient Cu(In,Ga)Se2 films of band gap ~1.15 eV fabricated by this process consist of a single chalcopyrite phase and device efficiencies up to12.4% were achieved for the composition ratios (x, y) = (0.30, 0.88). Correspondence between energy dispersive X--ray spectroscopy (EDS), X--ray diffraction, transmission and reflection (T&R), four--point probe resistivity, and current density--voltage (J--V) measurements indicate that increased Cu concentration leads to the incorporation of a secondary phase Cu2-xSe compound in the Cu(In,Ga)Se2 films, which is detrimental to cell performance. The third objective of this work is to evaluate the Cu2-xSe material properties by employing in--situ RTSE, as well as ex--situ SE and various other characterization techniques. SE revealed that the dielectric function spectra of Cu2-xSe evolve with temperature, providing insights into the evolution of transport properties and critical point structures. At room temperature, semi--metallic behavior of Cu2-xSe thin films was revealed by SE and Hall Effect measurements. These characteristics serve as key inputs for optical modeling of complex layer structures of Cu(In,Ga)Se2 films grown by 2-- and 3--step processes.

  19. Impact of secondary barriers on copper-indium-gallium-selenide solar-cell operation

    Microsoft Academic Search

    Alexei O. Pudov

    2005-01-01

    Thin-film solar cells based on CuInSe2 (CIS) absorber with a band gap of Eg = 1.0 eV and also based on CuIn1-x GaxSe2 (CIGS) alloy absorbers with a band-gap range of Eg = 1.0--1.67 eV are investigated in this work. Intermediate \\

  20. New deposition process of copper(indium, gallium) selenide thin films for solar cell applications

    Microsoft Academic Search

    Himal Khatri

    2010-01-01

    Molybdenum (Mo) is currently the most common material used for Cu(In,Ga)Se 2 solar cell back contacts. The first objective of this study is to utilize in--situ and ex--situ characterization techniques to investigate the growth, as well as the physical and chemical properties, of Mo thin films deposited by RF magnetron sputtering onto soda-- lime glass (SLG) substrates. The effects of

  1. Co-solvent enhanced zinc oxysulfide buffer layers in Kesterite copper zinc tin selenide solar cells.

    PubMed

    Steirer, K Xerxes; Garris, Rebekah L; Li, Jian V; Dzara, Michael J; Ndione, Paul F; Ramanathan, Kannan; Repins, Ingrid; Teeter, Glenn; Perkins, Craig L

    2015-06-01

    A co-solvent, dimethylsulfoxide (DMSO), is added to the aqueous chemical "bath" deposition (CBD) process used to grow ZnOS buffer layers for thin film Cu2ZnSnSe4 (CZTSe) solar cells. Device performance improves markedly as fill factors increase from 0.17 to 0.51 upon the co-solvent addition. X-ray photoelectron spectroscopy (XPS) analyses are presented for quasi-in situ CZTSe/CBD-ZnOS interfaces prepared under an inert atmosphere and yield valence band offsets equal to -1.0 eV for both ZnOS preparations. When combined with optical band gap data, conduction band offsets exceed 1 eV for the water and the water/DMSO solutions. XPS measurements show increased downward band bending in the CZTSe absorber layer when the ZnOS buffer layer is deposited from water only. Admittance spectroscopy data shows that the ZnOS deposited from water increases the built-in potential (Vbi) yet these solar cells perform poorly compared to those made with DMSO added. The band energy offsets imply an alternate form of transport through this junction. Possible mechanisms are discussed, which circumvent the otherwise large conduction band spike between CZTSe and ZnOS, and improve functionality with the low-band gap absorber, CZTSe (Eg = 0.96 eV). PMID:26000570

  2. Structure-fluctuation-induced abnormal thermoelectric properties in semiconductor copper selenide

    SciTech Connect

    Liu, Huili [Chinese Academy of Sciences; Shi, Xun [Chinese Academy of Sciences; Kirkham, Melanie J [ORNL; Wang, Hsin [ORNL; Li, Qiang [Brookhaven National Laboratory (BNL); Uher, Ctirad [University of Michigan; Zhang, Wenqing [Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS); Chen, Lidong [Chinese Academy of Sciences

    2013-01-01

    Thermoelectric effects and related technologies have attracted a great interest due to the world-wide energy harvesting. Thermoelectricity has usually been considered in the context of stable material phases. Here we report that the fluctuation of structures during the second-order phase transition in Cu2Se semiconductor breaks the conventional trends of thermoelectric transports in normal phases, leading to a critically phase-transition-enhanced thermoelectric figure of merit zT above unity at 400K, a three times larger value than for the normal phases. Dynamic structural transformations introduce intensive fluctuations and extreme complexity, which enhance the carrier entropy and thus the thermopower, and strongly scatter carriers and phonons as well to make their transports behave critically.

  3. Effect of bath temperature on the electrodeposition of copper tin selenide films from aqueous solution

    Microsoft Academic Search

    Zulkarnain Zainal; Anuar Kassim; Mohd Zobir Hussein; Chuah Hang Ching

    2004-01-01

    The effect of bath temperature on Cu2SnSe4 films prepared by electrodeposition was studied in this work. The structure, morphology and composition of the films were analysed by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDAX). The band gap energy and type of optical transition were determined from optical absorbance data. The results showed

  4. Nanoparticle Oxides Precursor Inks for Thin film Copper Indium Gallium Selenide (CIGS) Solar Cells

    Microsoft Academic Search

    Vijay K. Kapur; Matthew Fisher; Robin Roe

    2001-01-01

    The paper describes ISET's patented non-vacuum process for low cost mass production of CIGS solar cells. In this process, the water based precursor inks of mixed oxides are deposited on various conducting substrates by a variety of non-vacuum coating techniques. The oxides are converted to CIGS by annealing and the device is completed by deposition of CdS by CBD followed

  5. Computer Simulation of Liquid Copper Tellurides and Silver Selenide from Diffraction Data

    Microsoft Academic Search

    D. K. Belashchenko; O. I. Ostrovski

    2004-01-01

    The structural models of liquid Ag2Se, CuTe, and Cu2Te are constructed from available diffraction data using molecular dynamics simulations with the BELION algorithm. The structural characteristics of the models are in good agreement with the diffraction data, and the calculated atomization energies agree with thermodynamic estimates. The charge state of the Ag ion is close to 1+, and those of

  6. Device physics of copper(indium,gallium)selenide(2) thin-film solar cells

    Microsoft Academic Search

    Markus Gloeckler

    2005-01-01

    Thin-film solar cells have the potential to be an important contributor to the global energy demand by the mid-21st-century. Cu(In,Ga)Se 2 (CIGS) solar cells, which have achieved laboratory efficiencies close to 20%, are highly attractive, because their band gap is near the optimal value, their polycrystallinity is not significantly detrimental to their performance, and the broad choice of heterojunction partners

  7. Enzymatic methylation of sulfide, selenide, and organic thiols by Tetrahymena thermophila

    SciTech Connect

    Drotar, A.; Fall, L.R.; Mishalanie, E.A.; Tavernier, J.E.; Fall, R.

    1987-09-01

    Cell extracts from the ciliate Tetrahymena thermophila catalyzed the S-adenosylmethionine-dependent methylation of sulfide. The product of the reaction, methanethiol, was detected by a radiometric assay and by a gas-chromatographic assay coupled to a sulfur-selective chemiluminescence detector. Extracts also catalyzed the methylation of selenide, and the product was shown by gas chromatography-mass spectrometry to be methaneselenol. The sulfide and selenide methyltransferase activities copurified with the aromatic thiol methyltransferase previously characterized from this organism, but heat inactivation experiments suggested the involvement of distinct sulfide and selenide methyltransferases. Short-term toxicity tests were carried out for sulfide, selenide, and their methylated derivatives; the monomethylated forms were somewhat more toxic than the nonmethylated or dimethylated compounds. Cell suspensions of T. thermophila exposed to sulfide, methanethiol, or their selenium analogs emitted methylated derivatives into the headspace. These results suggest that this freshwater protozoan is capable of the stepwise methylation of sulfide and selenide, leading to the release of volatile methylated sulfur or selenium gases.

  8. Selenium-coated carbon electrode for anodic stripping voltammetric determination of copper(II)

    Microsoft Academic Search

    Yukio Nagaosa; Ping Zong; Akihiro Kamio

    2009-01-01

    We describe a new and promising type of selenium film electrode for anodic stripping voltammetry. This method is based on\\u000a formation of copper selenide onto an in-situ formed selenium-film carbon electrode, this followed by Osteryoung square-wave\\u000a anodic stripping voltammetry. Copper(II) is also in-situ electroplated in a test solution containing 0.01 mol L-1 hydrochloric acid, 0.05 mol L?1 potassium chloride and 500 µg L?1 Se(IV) at a

  9. Thermoelectric characterization of individual bismuth selenide topological insulator nanoribbons.

    PubMed

    Tang, Hao; Wang, Xiaomeng; Xiong, Yucheng; Zhao, Yang; Zhang, Yin; Zhang, Yan; Yang, Juekuan; Xu, Dongyan

    2015-04-21

    Bismuth selenide (Bi2Se3) nanoribbons have attracted tremendous research interest recently to study the properties of topologically protected surface states that enable new opportunities to enhance the thermoelectric performance. However, the thermoelectric characterization of individual Bi2Se3 nanoribbons is rare due to the technological challenges in the measurements. One challenge is to ensure good contacts between the nanoribbon and electrodes in order to determine the thermal and electrical properties accurately. In this work, we report the thermoelectric characterization of individual Bi2Se3 nanoribbons via a suspended microdevice method. Through careful measurements, we have demonstrated that contact thermal resistance is negligible after the electron-beam-induced deposition (EBID) of platinum/carbon (Pt/C) composites at the contacts between the nanoribbon and electrodes. It is shown that the thermal conductivity of the Bi2Se3 nanoribbons is less than 50% of the bulk value over the whole measurement temperature range, which can be attributed to enhanced phonon boundary scattering. Our results indicate that intrinsic Bi2Se3 nanoribbons prepared in this work are highly doped n-type semiconductors, and therefore the Fermi level should be in the conduction band and no topological transport behavior can be observed in the intrinsic system. PMID:25798738

  10. Thermoelectric characterization of individual bismuth selenide topological insulator nanoribbons

    NASA Astrophysics Data System (ADS)

    Tang, Hao; Wang, Xiaomeng; Xiong, Yucheng; Zhao, Yang; Zhang, Yin; Zhang, Yan; Yang, Juekuan; Xu, Dongyan

    2015-04-01

    Bismuth selenide (Bi2Se3) nanoribbons have attracted tremendous research interest recently to study the properties of topologically protected surface states that enable new opportunities to enhance the thermoelectric performance. However, the thermoelectric characterization of individual Bi2Se3 nanoribbons is rare due to the technological challenges in the measurements. One challenge is to ensure good contacts between the nanoribbon and electrodes in order to determine the thermal and electrical properties accurately. In this work, we report the thermoelectric characterization of individual Bi2Se3 nanoribbons via a suspended microdevice method. Through careful measurements, we have demonstrated that contact thermal resistance is negligible after the electron-beam-induced deposition (EBID) of platinum/carbon (Pt/C) composites at the contacts between the nanoribbon and electrodes. It is shown that the thermal conductivity of the Bi2Se3 nanoribbons is less than 50% of the bulk value over the whole measurement temperature range, which can be attributed to enhanced phonon boundary scattering. Our results indicate that intrinsic Bi2Se3 nanoribbons prepared in this work are highly doped n-type semiconductors, and therefore the Fermi level should be in the conduction band and no topological transport behavior can be observed in the intrinsic system.

  11. Contrasting role of antimony and bismuth dopants on the thermoelectric performance of lead selenide.

    PubMed

    Lee, Yeseul; Lo, Shih-Han; Chen, Changqiang; Sun, Hui; Chung, Duck-Young; Chasapis, Thomas C; Uher, Ctirad; Dravid, Vinayak P; Kanatzidis, Mercouri G

    2014-01-01

    Increasing the conversion efficiency of thermoelectric materials is a key scientific driver behind a worldwide effort to enable heat to electricity power generation at competitive cost. Here we report an increased performance for antimony-doped lead selenide with a thermoelectric figure of merit of ~1.5 at 800?K. This is in sharp contrast to bismuth doped lead selenide, which reaches a figure of merit of <1. Substituting antimony or bismuth for lead achieves maximum power factors between ~23-27??W?cm(-1)?K(-2) at temperatures above 400?K. The addition of small amounts (~0.25?mol%) of antimony generates extensive nanoscale precipitates, whereas comparable amounts of bismuth results in very few or no precipitates. The antimony-rich precipitates are endotaxial in lead selenide, and appear remarkably effective in reducing the lattice thermal conductivity. The corresponding bismuth-containing samples exhibit smaller reduction in lattice thermal conductivity. PMID:24784991

  12. Two-dimensional tin selenide nanostructures for flexible all-solid-state supercapacitors.

    PubMed

    Zhang, Chunli; Yin, Huanhuan; Han, Min; Dai, Zhihui; Pang, Huan; Zheng, Yulin; Lan, Ya-Qian; Bao, Jianchun; Zhu, Jianmin

    2014-04-22

    Due to their unique electronic and optoelectronic properties, tin selenide nanostructures show great promise for applications in energy storage and photovoltaic devices. Despite the great progress that has been achieved, the phase-controlled synthesis of two-dimensional (2D) tin selenide nanostructures remains a challenge, and their use in supercapacitors has not been explored. In this paper, 2D tin selenide nanostructures, including pure SnSe2 nanodisks (NDs), mixed-phase SnSe-SnSe2 NDs, and pure SnSe nanosheets (NSs), have been synthesized by reacting SnCl2 and trioctylphosphine (TOP)-Se with borane-tert-butylamine complex (BTBC) and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone. Utilizing the interplay of TOP and BTBC and changing only the amount of BTBC, the phase-controlled synthesis of 2D tin selenide nanostructures is realized for the first time. Phase-dependent pseudocapacitive behavior is observed for the resulting 2D nanostructures. The specific capacitances of pure SnSe2 NDs (168 F g(-1)) and SnSe NSs (228 F g(-1)) are much higher than those of other reported materials (e.g., graphene-Mn3O4 nanorods and TiN mesoporous spheres); thus, these tin selenide materials were used to fabricate flexible, all-solid-state supercapacitors. Devices fabricated with these two tin selenide materials exhibited high areal capacitances, good cycling stabilities, excellent flexibilities, and desirable mechanical stabilities, which were comparable to or better than those reported recently for other solid-state devices based on graphene and 3D GeSe2 nanostructures. Additionally, the rate capability of the SnSe2 NDs device was much better than that of the SnSe NS device, indicating that SnSe2 NDs are promising active materials for use in high-performance, flexible, all-solid-state supercapacitors. PMID:24601530

  13. Spin-Polarized Tunneling Study on Spin-Momentum Locking in the Topological Insulator Bismuth Selenide

    NASA Astrophysics Data System (ADS)

    Chen, Ching-Tzu; Liu, Luqiao; Richardella, Anthony; Garate, Ion; Zhu, Yu; Samarth, Nitin

    2015-03-01

    In this talk, we will demonstrate that the helical spin texture on topological insulator (TI) surfaces can be electrically detected using four-terminal tunnel junction devices with ferromagnetic top electrodes. Consistent results are obtained in both the Edelstein and spin-galvanic effect configurations, allowing a quantitative determination of the charge-spin conversion efficiency in bismuth selenide. By applying finite DC biases at the junction, we further extract the energy dependence of the effective spin polarization in bismuth selenide. The observed temperature stability up to 200K suggests that TIs can be highly promising for room-temperature spintronics applications

  14. Hot wire chemical vapor deposition of germanium selenide thin films for nonvolatile random access memory applications

    NASA Astrophysics Data System (ADS)

    Reso, D.; Silinskas, M.; Lisker, M.; Schubert, A.; Burte, E. P.

    2011-04-01

    Thin films of germanium selenide (GexSe100-x with 0selenide films covered and subsequently diffused by silver were used as programmable metallization cells for a verification of the electrical switching properties.

  15. Solid-gas phase equilibria and thermodynamic properties of cadmium selenide.

    NASA Technical Reports Server (NTRS)

    Sigai, A. G.; Wiedemeier, H.

    1972-01-01

    Accurate vapor pressures are determined through direct weight loss measurements using the Knudsen effusion technique. The experimental data are evaluated by establishing the mode of vaporization and determining the heat capacity of cadmium selenide at elevated temperatures. Additional information is obtained through a second- and third-law evaluation of data, namely, the heat of formation and the absolute entropy of cadmium selenide. A preferential loss of selenium during the initial heating of CdSe is observed, which leads to a deviation in stoichiometry.

  16. Ionothermal syntheses of nano- and microstructured ternary copper-indium-chalcogenides.

    PubMed

    Tyrrell, Sophie; Behrendt, Gereon; Nockemann, Peter

    2015-05-01

    Ternary compounds of copper indium selenide nano- and microsized materials were prepared through colloidal synthesis using an indium(III) selenide precursor and copper(I) chloride via a microwave-assisted ionothermal route. The indium(III) selenide precursor used in the reaction was formed in situ from a diphenyl diselenide precursor and chloroindate(III) ionic liquids (ILs), also via a microwave-assisted ionothermal route. The crystal structures of three intermediates, namely, CuCl2(OMe)2(H2O)){Cu(PhSeO2)2}n, [CuCl(Se2Ph2)2]n, and [C8mim]3{Cu(I)Cl2Cu(II)OCl8}n, were determined after formation through a ionothermal procedure utilizing metal-containing imidazolium ILs and a selenium precursor with conventional heating. Herein, we compare the use of microwave irradiation over conventional heating with different ILs on the stoichiometry of the resulting products. The influence of the reaction temperature, reaction time, order of addition of reagents, and variation of ILs, which were characterized using PXRD, SEM, and EDX, on the final products was investigated. PMID:25898272

  17. Dispersion strengthened copper

    DOEpatents

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

    1990-01-01

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

  18. Dispersion strengthened copper

    DOEpatents

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

    1989-01-01

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

  19. Electroelastic Properties of the Sulfides, Selenides, and Tellurides of Zinc and Cadmium

    Microsoft Academic Search

    Don Berlincourt; Hans Jaffe; L. R. Shiozawa

    1963-01-01

    A complete set of elastic, piezoelectric, and dielectric constants is presented for the sulfides, selenides, and tellurides of zinc and cadmium. The piezoelectric constants for the hexagonal crystals in this group are markedly higher than for the cubic crystals. An elementary model theory applied to these data leads to electric charges on the metal atom increasing from +0.066 e for

  20. Enhancement of thermoelectric figure-of-merit by resonant states of aluminium doping in lead selenide

    E-print Network

    Zhang, Qinyong

    By adding aluminium (Al) into lead selenide (PbSe), we successfully prepared n-type PbSe thermoelectric materials with a figure-of-merit (ZT) of 1.3 at 850 K. Such a high ZT is achieved by a combination of high Seebeck ...

  1. Similar behaviors of sulfide and selenide-based chalcogenide glasses to form glass ceramics

    Microsoft Academic Search

    Laurent Calvez; Changgui Lin; Mathieu Rozé; Yannick Ledemi; Erwan Guillevic; Bruno Bureau; Mathieu Allix; Xianghua Zhang

    2010-01-01

    In this paper, the strong influence of alkali halide in chalcogenide glasses is reminded, leading for the first time to highly transparent glasses from the visible range up to 11mum. The behavior of crystallization has been demonstrated to be similar in sulfide and selenide glasses containing gallium as well. The structural evolution of several glass compositions from the Ge-Ga-S or

  2. G. J. Snyder Page 1 of 6 THERMOELECTRIC PROPERTIES OF CR3S4-TYPE SELENIDES

    E-print Network

    devices depends primarily on increasing the figure of merit, ZT, for thermoelectric materials. The figureG. J. Snyder Page 1 of 6 THERMOELECTRIC PROPERTIES OF CR3S4-TYPE SELENIDES G. Jeffrey Snyder*, T4 structure type have been studied for their thermoelectric properties. All exhibit low lattice

  3. Near-Field Infrared Sum-Frequency Generation Imaging of Chemical Vapor Deposited Zinc Selenide

    E-print Network

    Cohen, Ronald C.

    Near-Field Infrared Sum-Frequency Generation Imaging of Chemical Vapor Deposited Zinc Selenide-frequency generation (SFG) has been detected with near-field scanning optical microscopy (NSOM) for the first time. SFG. Detection of SFG with near-field scanning optical microscopy (NSOM) transcends both of these difficulties

  4. Recovery of Silver and Gold from Copper Anode Slimes

    NASA Astrophysics Data System (ADS)

    Chen, Ailiang; Peng, Zhiwei; Hwang, Jiann-Yang; Ma, Yutian; Liu, Xuheng; Chen, Xingyu

    2015-02-01

    Copper anode slimes, produced from copper electrolytic refining, are important industrial by-products containing several valuable metals, particularly silver and gold. This article provides a comprehensive overview of the development of the extraction processes for recovering silver and gold from conventional copper anode slimes. Existing processes, namely pyrometallurgical processes, hydrometallurgical processes, and hybrid processes involving the combination of pyrometallurgical and hydrometallurgical technologies, are discussed based in part on a review of the form and characteristics of silver and gold in copper anode slimes. The recovery of silver and gold in pyrometallurgical processes is influenced in part by the slag and matte/metal chemistry and related characteristics, whereas the extraction of these metals in hydrometallurgical processes depends on the leaching reagents used to break the structure of the silver- and gold-bearing phases, such as selenides. By taking advantage of both pyrometallurgical and hydrometallurgical techniques, high extraction yields of silver and gold can be obtained using such combined approaches that appear promising for efficient extraction of silver and gold from copper anode slimes.

  5. Recovery of Silver and Gold from Copper Anode Slimes

    NASA Astrophysics Data System (ADS)

    Chen, Ailiang; Peng, Zhiwei; Hwang, Jiann-Yang; Ma, Yutian; Liu, Xuheng; Chen, Xingyu

    2014-09-01

    Copper anode slimes, produced from copper electrolytic refining, are important industrial by-products containing several valuable metals, particularly silver and gold. This article provides a comprehensive overview of the development of the extraction processes for recovering silver and gold from conventional copper anode slimes. Existing processes, namely pyrometallurgical processes, hydrometallurgical processes, and hybrid processes involving the combination of pyrometallurgical and hydrometallurgical technologies, are discussed based in part on a review of the form and characteristics of silver and gold in copper anode slimes. The recovery of silver and gold in pyrometallurgical processes is influenced in part by the slag and matte/metal chemistry and related characteristics, whereas the extraction of these metals in hydrometallurgical processes depends on the leaching reagents used to break the structure of the silver- and gold-bearing phases, such as selenides. By taking advantage of both pyrometallurgical and hydrometallurgical techniques, high extraction yields of silver and gold can be obtained using such combined approaches that appear promising for efficient extraction of silver and gold from copper anode slimes.

  6. Shape-controlled colloidal synthesis of rock-salt lead selenide nanocrystals.

    PubMed

    Jawaid, Ali M; Asunskis, Daniel J; Snee, Preston T

    2011-08-23

    Developing simple synthetic methods to control the size and morphology of nanocrystals is an active area of research as these parameters control the material's electronic and optical properties. For a semiconductor with a symmetrical crystal structure such as lead selenide, anisotropic colloidal growth has been previously accomplished via the use of templates, seeds, or by block assembly of smaller, symmetrical subunits. Here, we present a simple method to create monodisperse lead selenide nanorods and multipods at low temperatures. The size distribution and the observed morphologies are consistent with a continuous, anisotropic growth of material. The syntheses of these anisotropic shapes are due to the nature of the nuclei that form upon injection of precursors into partially oxidized alkene solvents that may contain lactone and carbonate-functional derivatives. PMID:21770427

  7. Theory of two-magnon Raman scattering in alkaline iron selenide superconductors

    NASA Astrophysics Data System (ADS)

    Liu, C. S.; Zhang, A. M.; Xu, T. F.; Wu, W. C.

    2014-11-01

    Motivated by the recent experiment of two-magnon Raman scattering in alkaline iron selenide superconductors (Zhang et al., 2012), we investigate in details the underlying spin interactions of the ?{5}×?{5} antiferromagnetic superstructure. Based on the linear spin wave approximation, the Fleury-London (FL) two-magnon Raman cross-sections are calculated. By comparing theoretical results with the Raman data in both Ag and Bg channels, an optimal set of exchange parameters which are consistent with the fitting to the neutron scattering data are obtained. It reveals that the experimentally observed broad and asymmetric peaks around 1600 cm-1 are dominantly originated from quasiparticle excitations in two nearly degenerate magnon bands in the (0,±?) and (±?,0) directions. The result thus supports that the magnetic properties in alkaline iron selenide AFe1.6+xSe6 superconductors can be basically described by the quantum spin model with up to third nearest-neighbor exchange couplings.

  8. Structural and physical properties of mercury-iron selenide layers and quantum wells

    Microsoft Academic Search

    D. Schikora; Th. Widmer; K. Lischka; P. Schäfer; G. Machel; S. Luther; M. von Ortenberg

    1995-01-01

    Epitaxial layers and single quantum wells (SQW's) of Fermi-level pinned mercury-iron selenide (HgSe:Fe) have been grown by molecular-beam epitaxy on ZnTe buffer layers and characterized by in situ reflection high-energy electron-diffraction (RHEED) and high-field magnetospectroscopy investigations. The onset of strain relaxation at the critical thickness has been determined by time-dependent intensity-profile analysis of different reflexes in the RHEED pattern. In

  9. Spray pyrolytic deposition and characterization of lanthanum selenide (La 2Se 3) thin films

    Microsoft Academic Search

    G. D. Bagde; S. D. Sartale; C. D. Lokhande

    2003-01-01

    The versatile spray pyrolysis technique was employed to prepare thin films of lanthanum selenide (La2Se3) on glass and fluorine doped tin oxide (FTO) coated glass substrates under optimized conditions. The deposition temperature was 250°C. The X-ray studies reveal that the films are polycrystalline with single La2Se3 phase. The estimated optical band gap was found to be 2.6eV. The dielectric properties

  10. The paramagnetic properties of iron selenides with NiAs-type structure

    Microsoft Academic Search

    Peter Terzieff; Kurt L. Komarek

    1978-01-01

    The magnetic properties of the ferrimagnetic iron selenides with NiAs type structure between 51 and 59 at % Se have been investigated using a magnetic balance adapted for measurements up to 800°C. The magnetic susceptibilities of monoclinic ß-Fe1-xSe and hexagonal ?-Fe1-xSe with emphasis on stoichiometric Fe3Se4 and Fe7Se8 were studied in the paramagnetic region, and from the results phase boundaries

  11. Hot wire chemical vapor deposition of germanium selenide thin films for nonvolatile random access memory applications

    Microsoft Academic Search

    D. Reso; M. Silinskas; M. Lisker; A. Schubert; E. P. Burte

    2011-01-01

    Thin films of germanium selenide (GexSe100-x with 0

  12. Chemically deposited thin films of sulfides and selenides of antimony and bismuth as solar energy materials

    NASA Astrophysics Data System (ADS)

    Nair, M. T.; Nair, Padmanabhan K.; Garcia, V. M.; Pena, Y.; Arenas, O. L.; Garcia, J. C.; Gomez-Daza, O.

    1997-10-01

    Chemical bath deposition techniques for bismuth sulfide, bismuth selenide, antimony sulfide, and antimony selenide thin films of about 0.20 - 0.25 micrometer thickness are reported. All these materials may be considered as solar absorber films: strong optical absorption edges, with absorption coefficient, (alpha) , greater than 104 cm-1, are located at 1.31 eV for Bi2Se3, 1.33 eV for Bi2S3, 1.8 eV for Sb2S3, and 1.35 eV for Sb2Se3. As deposited, all the films are nearly amorphous. However, well defined crystalline peaks matching bismuthinite (JCPDS 17- 0320), paraguanajuatite (JCPDS 33-0214), and stibnite (JCPDS 6-0474) and antimony selenide (JCPDS 15-0861) for Bi2S3, Bi2Se3, Sb2S3 and Sb2Se3 respectively, are observed when the films are annealed in nitrogen at 300 degrees Celsius. This is accompanied by a substantial modification of the electrical conductivity in the films: from 10-7 (Omega) -1 cm-1 (in as prepared films) to 10 (Omega) -1 cm-1 in the case of bismuth sulfide and selenide films, and enhancement of photosensitivity in the case of antimony sulfide films. The chemical deposition of a CuS/CuxSe film on these Vx- VIy films and subsequent annealing at 300 degrees Celsius for 1 h at 1 torr of nitrogen leads to the formation of p-type films (conductivity of 1 - 100 (Omega) -1 cm-1) of multinary composition. Among these, the formation of Cu3BiS3 (JCPDS 9-0488) and Cu3SbS4 (JCPDS 35- 0581), CuSbS2 (JCPDS 35-0413) have been clearly detected. Solar energy applications of these films are suggested.

  13. Atomic layer deposition of metal tellurides and selenides using alkylsilyl compounds of tellurium and selenium.

    PubMed

    Pore, Viljami; Hatanpää, Timo; Ritala, Mikko; Leskelä, Markku

    2009-03-18

    Atomic layer deposition (ALD) of metal selenide and telluride thin films has been limited because of a lack of precursors that would at the same time be safe and exhibit high reactivity as required in ALD. Yet there are many important metal selenide and telluride thin film materials whose deposition by ALD might be beneficial, for example, CuInSe2 for solar cells and Ge2Sb2Te5 for phase-change random-access memories. Especially in the latter case highly conformal deposition offered by ALD is essential for high storage density. By now, ALD of germanium antimony telluride (GST) has been attempted only using plasma-assisted processes owing to the lack of appropriate tellurium precursors. In this paper we make a breakthrough in the development of new ALD precursors for tellurium and selenium. Compounds with a general formula (R3Si)2Te and (R3Si)2Se react with various metal halides forming the corresponding metal tellurides and selenides. As an example, we show that Sb2Te3, GeTe, and GST films can be deposited by ALD using (Et3Si)2Te, SbCl3, and GeCl2 x C4H8O2 compounds as precursors. All three precursors exhibit a typical saturative ALD growth behavior and GST films prepared at 90 degrees C show excellent conformality on a high aspect-ratio trench structure. PMID:19123860

  14. Copper Cleanup

    NSDL National Science Digital Library

    2013-12-05

    In this hands-on experiment, kids use chemistry to explore whether acids or bases are better at restoring a penny’s shine. Kids follow the scientific process to test a common household cleaning products alongside ketchup, cola, and other kitchen staples, and may be surprised by the results! A downloadable data sheet is available on the Copper Cleanup activity resources page.

  15. Defect levels in indium and gallium doped zinc selenide

    NASA Astrophysics Data System (ADS)

    Qidwai, A. A.; Woods, J.

    1982-09-01

    Indium and gallium dopants in ZnSe display unusual properties in that although they act as shallow donors in low concentration, complex compensation effects appear to occur at high concentration, so that the resistivity increases with increasing impurity content. In order to investigate these effects, the techniques of transient photocapacitance and transient photocurrent have been used to study the incidence of deep levels in Schottky diodes formed on ZnSe: In and ZnSe: Ga. Shallow levels have also been investigated using the photocapacitance method advocated by Marfaing. In indium doped crystals, acceptor levels were found at 0.59 and 0.41 eV above the valence band. The acceptor at 0.59 eV is identified as the zinc vacancy-substitutional indium complex part of the self-activated luminescence centre. The 0.41 eV acceptor became more apparent as the indium content was increased and presumably contributes to the observed donor compensation effects. For comparison diodes fabricated on copper doped ZnSe were examined and found to exhibit an acceptor level at 0.67 eV.

  16. Dispersion strengthened copper

    DOEpatents

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

    1990-01-09

    A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.

  17. 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, ...

  18. Copper Extraction Demonstration

    NSDL National Science Digital Library

    Summary This demonstration uses sulfuric acid and crushed copper ore (malachite) to produce a solution of copper sulfate and carbonic acid in a beaker. When a freshly sanded nail is dropped into the copper sulfate ...

  19. Ovonic switching in tin selenide thin films. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Baxter, C. R.

    1974-01-01

    Amorphous tin selenide thin films which possess Ovonic switching properties were fabricated using vacuum deposition techniques. Results obtained indicate that memory type Ovonic switching does occur in these films the energy density required for switching from a high impedance to a low impedance state is dependent on the spacing between the electrodes of the device. The switching is also function of the magnitude of the applied voltage pulse. A completely automated computer controlled testing procedure was developed which allows precise control over the shape of the applied voltage switching pulse. A survey of previous experimental and theoretical work in the area of Ovonic switching is also presented.

  20. Scaling and spatial analysis of the dielectric response of cadmium selenide nanowires

    NASA Astrophysics Data System (ADS)

    Kanai, Yosuke; Cicero, Giancarlo

    2014-10-01

    Transverse dielectric response of hexagonal cadmium selenide (CdSe) nanowires was investigated using first-principles quantum mechanical calculations. Scaling behavior of polarizability was found to closely follow a simple dielectric cylinder model even for small nanowires with a diameter of a few nanometers. The spatial dependence of the dielectric response in the nanowires was analyzed in terms of maximally localized Wannier functions in order to elucidate the model behavior. Localized d electrons at cadmium atoms were found responsible for the simple analytic scaling of the polarizability, and the dielectric response in the center of nanowire was found converged to that of bulk already for 3 nm diameter nanowires.

  1. Molecular Structure of Copper

    NSDL National Science Digital Library

    2003-04-10

    Man has known of copper since antiquity. Copper is known for its unique reddish hue, its good electrical and thermal conductivity, and widespread abundance. It is malleable and extremely ductile. Copper melts at 1357 degrees kelvin and boils at 2840 degrees kelvin. Copper crystals are commonly found in cubic and dodecahedral forms. Copper is widely used in wiring and electronics. Two important alloys of copper are brass and bronze. Also, all American coins are now made of copper alloys. Humans require trace amounts of copper; larger doses result in poisoning.

  2. Turkey liver xanthine dehydrogenase. Reactivation of the cyanide-inactivated enzyme by sulphide and by selenide

    PubMed Central

    Cleere, William F.; Coughlan, Michael P.

    1974-01-01

    1. Turkey liver xanthine dehydrogenase engaged in catalysing the oxidation of xanthine by dichlorophenol–indophenol was progressively inactivated by methanol. This inactivation was reversible by NAD+. 2. Reaction with arsenite and with cyanide, in each case first-order with respect to enzyme, resulted in characteristic alterations in the visible absorption spectrum of the enzyme. The rate of spectral change on reaction with either agent paralleled the rate of loss of enzyme activity. 3. Cyanide inactivation was accompanied by elimination from the enzyme of sulphur as thiocyanate. Partial restoration of activity was effected by incubation with sulphide or with selenide. The results suggest that turkey liver xanthine dehydrogenase, like milk xanthine oxidase (Massey & Edmonson, 1970), contains at the active centre a cyanolysable persulphide group essential to catalytic activity and that selenium may replace sulphur in this group to give an active enzyme. 4. Incubation of the native enzyme with sulphide or with selenide resulted in the rapid loss of half of the xanthine-oxidizing activity, apparently by disrupting the molybdenum and (Fe/S)II loci. This may indicate non-equivalence of the intramolecular electron-transfer systems. PMID:4462558

  3. Magnetic states of the two-leg-ladder alkali metal iron selenides AFe2Se3

    NASA Astrophysics Data System (ADS)

    Luo, Qinlong; Nicholson, Andrew; Rincón, Julián; Liang, Shuhua; Riera, José; Alvarez, Gonzalo; Wang, Limin; Ku, Wei; Samolyuk, German D.; Moreo, Adriana; Dagotto, Elbio

    2013-01-01

    Recent neutron scattering experiments addressing the magnetic state of the two-leg-ladder selenide compound BaFe2Se3 have unveiled a dominant spin arrangement involving ferromagnetically ordered 2×2 iron superblocks, that are antiferromagnetically coupled among them (the ``block-AFM''state). Using the electronic five-orbital Hubbard model first-principles techniques to calculate the electronic hopping amplitudes between irons, and the real-space Hartree-Fock approximation to handle the many-body effects, here it is shown that the exotic block-AFM state is indeed stable at realistic electronic densities close to n˜6.0. Another state with parallel spins along the rungs and antiparallel along the legs of the ladders (the “CX” state) is close in energy. This state becomes stable in other portions of the phase diagrams, such as with hole doping, as also found experimentally via neutron scattering applied to KFe2Se3. In addition, the present study unveils other competing magnetic phases that could be experimentally stabilized by varying either n chemically or the electronic bandwidth by pressure. Similar results were obtained using two-orbital models, studied here via Lanczos and density-matrix renormalization group (DMRG) techniques. A comparison of the results obtained with the realistic selenides hopping amplitudes for BaFe2Se3 against those found using the hopping amplitudes for pnictides reveals several qualitative similarities, particularly at intermediate and large Hubbard couplings.

  4. Characterization of nanostructured iron selenide thin films grown by chemical route at room temperature

    SciTech Connect

    Ubale, A.U., E-mail: ashokuu@yahoo.com [Nanostructured Thin Film Materials Laboratory, Department of Physics, Govt. Vidarbha Institute of Science and Humanities, VMV Road, Amravati 444604, Maharashtra (India); Sakhare, Y.S.; Belkedkar, M.R. [Nanostructured Thin Film Materials Laboratory, Department of Physics, Govt. Vidarbha Institute of Science and Humanities, VMV Road, Amravati 444604, Maharashtra (India)] [Nanostructured Thin Film Materials Laboratory, Department of Physics, Govt. Vidarbha Institute of Science and Humanities, VMV Road, Amravati 444604, Maharashtra (India); Singh, Arvind [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India)] [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India)

    2013-02-15

    Highlights: ? Nanostructured FeSe thin films were successfully synthesized at room temperature by CBD method. ? The XRD and EDAX characterization confirms nanocrystalline nature of FeSe. ? The SEM and AFM show microporous morphology with nanorods and nanoplates of FeSe. -- Abstract: Iron selenide thin films have been deposited onto glass substrates by using chemical bath deposition technique. Structural characterization of iron selenide thin films was carried out by means of X-ray diffraction and Fourier transforms infrared spectrum. The morphological characterization of FeSe thin film was carried out using scanning electron microscopy and atomic force microscopy, which revealed porous grain morphology of FeSe with some nano rectangular rods and plates grown on it. The as-deposited thin films exhibited optical band gap energy 2.60 eV. The as deposited FeSe thin films are semiconducting in nature with p-type electrical conductivity. The room temperature electrical resistivity is of the order of 1.1 × 10{sup 5} ?-cm with activation energy 0.26 and 0.95 eV, respectively, in low and high temperature region.

  5. Two-step synthesis of silver selenide semiconductor with a linear magnetoresistance effect

    NASA Astrophysics Data System (ADS)

    Yang, Fengxia; Xiong, Shuangtao; Xia, Zhengcai; Liu, Fengxian; Han, Chong; Zhang, Duanming

    2012-12-01

    A two-step synthesis method for polycrystalline ?-silver selenide (?-Ag2Se) was developed. In the first step, nanopowder was prepared using a chemical conversion method at room temperature. In the second step, the nanopowder was compressed and then the bulk Ag2Se was fabricated by the solid-state sintering process. The crystalline phase and morphology were examined. The results showed that ?-Ag2Se was fast fabricated at room temperature. The dense polycrystalline Ag-rich Ag2Se was synthesized successfully at 450 °C for 0.5 h under Argon flow. For the polycrystalline, the electronic properties and transverse magnetoresistance (TMR) in a pulsed magnetic field were investigated. The samples displayed n-type semiconducting behaviors and a critical temperature with a broaden temperature range of 140-150 K. Also, it presented a positive and nearly linear dependence on magnetic field H at H ? Hc (crossover field) ranging from 2 to 20 T. Moreover, the linear dependence of TMR at strong field was non-saturating up to 35 T. Combining with the observation of morphology, it is thought that this unusual TMR effect was caused by slightly excess Ag. This new synthesis method provided a potential route to synthesize nonstoichiometric silver selenide.

  6. Electrical Switching and Phase Transformation in Silver Selenide Nanowires David T. Schoen, Chong Xie, and Yi Cui*

    E-print Network

    Cui, Yi

    , California 94305 Received November 22, 2006; E-mail: yicui@stanford.edu Resistance switching in solid, they may offer the potential to study in depth the fundamental processes involved in resistance switchingElectrical Switching and Phase Transformation in Silver Selenide Nanowires David T. Schoen, Chong

  7. Methylselenol Formed by Spontaneous Methylation of Selenide Is a Superior Selenium Substrate to the Thioredoxin and Glutaredoxin Systems

    PubMed Central

    Gandin, Valentina; Misra, Sougat; Tisato, Francesco; Marzano, Cristina; Rigobello, Maria Pia; Kumar, Sushil; Björnstedt, Mikael

    2012-01-01

    Naturally occurring selenium compounds like selenite and selenodiglutathione are metabolized to selenide in plants and animals. This highly reactive form of selenium can undergo methylation and form monomethylated and multimethylated species. These redox active selenium metabolites are of particular biological and pharmacological interest since they are potent inducers of apoptosis in cancer cells. The mammalian thioredoxin and glutaredoxin systems efficiently reduce selenite and selenodiglutathione to selenide. The reactions are non-stoichiometric aerobically due to redox cycling of selenide with oxygen and thiols. Using LDI-MS, we identified that the addition of S-adenosylmethionine (SAM) to the reactions formed methylselenol. This metabolite was a superior substrate to both the thioredoxin and glutaredoxin systems increasing the velocities of the nonstoichiometric redox cycles three-fold. In vitro cell experiments demonstrated that the presence of SAM increased the cytotoxicity of selenite and selenodiglutathione, which could neither be explained by altered selenium uptake nor impaired extra-cellular redox environment, previously shown to be highly important to selenite uptake and cytotoxicity. Our data suggest that selenide and SAM react spontaneously forming methylselenol, a highly nucleophilic and cytotoxic agent, with important physiological and pharmacological implications for the highly interesting anticancer effects of selenium. PMID:23226364

  8. Shape-controlled solution synthesis of ferromagnetic copper chromium selenide (CuCr 2Se 4) crystallites

    NASA Astrophysics Data System (ADS)

    Rao, M. L.; Shamsuzzoha, M.; Gupta, A.

    2007-08-01

    Ferromagnetic crystallites of chalcospinel CuCr 2Se 4 have been synthesized in solution via a one-pot thermal decomposition of metal-acetylacetonate precursors in tri- n-octylamine. The reaction is carried out at temperatures of 300-350 °C in the presence of the cation precursor H 2Se, formed in situ by the reduction of Se powder in ?-sitosterol. Good control on the growth rate and the shape of the crystallites is obtained by varying the reaction time and temperature, and the concentration of Se. The crystallites are ferromagnetic at room temperature and under optimal synthesis conditions exhibit a low temperature magnetic moment of about 2.3 ?B per Cr, which is close to reported value for the bulk.

  9. The intra-absorber junction (IAJ) model for the device physics of copper indium selenide-based photovoltaics

    Microsoft Academic Search

    B. J. Stanbery

    2005-01-01

    The results of free-energy computational materials modeling (CMM) of the CIS ternary material system are applied to analysis of the processes of charge separation fundamental to the operation of all PV devices. It is known that all high-efficiency devices with CIS absorbers possess indium-rich compositions, which lie in the two-phase ?+? domain of the equilibrium CIS phase diagram. The intra-absorber

  10. Spectroscopic characterization of II-VI compounds and application to copper indium selenide-based solar cells

    NASA Astrophysics Data System (ADS)

    Aguilar Juarez, Heriberto De Jesus

    Structures consisting of CuInSe2 films, deposited on molybdenum-coated glass substrates and covered by CdS or ZnO thin films, for application in solar cells, have been characterized by spectroscopic ellipsometry, atomic force microscopy, photoluminescence and photovoltaic response. Computer aided simulations of the photovoltaic operation of these structures have been made to reinforce and complement the results of the characterization studies. The optical properties of CuInSe2, CdS and ZnO films over ranges of photon energies from 1.0 through 4.0 eV were determined. The measured optical bandgaps, 0.96 eV for CuInSe2, 2.35 eV for CdS and 3.33 eV for ZnO, are in good agreement with the values reported in the literature for bulk samples of those materials. In the case of CuInSe2, a second transition photon energy was detected at 1.02 eV. This transition was assumed to be due to gallium content in the CuInSe 2 film near the Mo interface. Depth structure profiles of the films were generated. The one for as-deposited CuInSe2 was found to include a surface layer (ODC layer) about 230 nm thick which exhibited optical properties considerably different from those of the bulk of the film. In the case of US (as might be expected for films grown by the chemical bath deposition technique) it was found that the films consist of two layers: a very compact one, about 29 nm thick, at the bottom of the film; and a much thicker and porous one, about 127 nm thick, on top. CdS/CuInSe2 and ZnO/CuInSe2 test cells were fabricated from substrates with as-deposited CuInSe2 and CuInSe2 from which a layer had been removed by etching. Test cells with CdS buffer layers on etched CuInSe2 exhibited degraded performance compared to cells fabricated on as-deposited CuInSe2. These results suggest that some interaction between US and the absorber material occurs in the case of etched absorbers. Thus, CdS may play a greater role than simply providing protection for the absorber layer during deposition of the TCO (top contact) layer. Photoluminescence measurements from plain CuInSe2 films, compared with similar measurements taken for CdS- or ZnO-coated films, showed an increase in the photoluminescence emission in the later cases, indicative of a reduction of nonradiative recombination caused by a passivating effect of the buffer layers on the interface. Numerical simulations of the operation of CuInSe2-based solar cells disclosed a mechanism by which the resistivity of the buffer layer may enhance the performance of the cells, and one that would promote inflected current-voltage characteristics. A comparison between the simulated performance of devices with experimentally determined results revealed the effects of a process-related connection between the resistivity of buffer layers and the electronic properties of the absorber, which have an impact on the conversion efficiencies of solar cells.

  11. Enhancement of copper(indium, gallium)selenide solar cells and materials via the incorporation of silver

    NASA Astrophysics Data System (ADS)

    Little, Scott A.

    As Cu(In,Ga)Se2 (CIGS) technology has proven itself to be a worthy solar cell technology, research efforts have redoubled to explore ways to enrich the already mature technology or create spin-offs of the technology with specific goals for manufacturing in mind. CIGS technology is now at an efficiency and production level that is competitive with other second generation solar cell devices and c-Si. Further research in CIGS allows for a toolbox of new ideas to try in the technology. This work aims at that goal by generating and presenting many ideas on how that may be possible. Primarily, this work contains information concerning the improvement of the manufacturing process using a hybrid sputter deposition chamber for scaling up and allowing for easy in situ monitoring using ellipsometry. It also explores the possibility of the addition of Ag to enhance and control device behavior and properties, and investigates the concept of a two-stage process with a co-sputtering deposition chamber. Monitoring of Ag in situ and in real time was explored to possibly improve the back contact of solar cells that use Ag as a back contact (not necessarily CIGS) and as a potential precursor for nanocrystals.

  12. Spectroscopic characterization of II-VI compounds and application to copper indium selenide-based solar cells

    Microsoft Academic Search

    Heriberto De Jesus Aguilar Juarez

    1999-01-01

    Structures consisting of CuInSe2 films, deposited on molybdenum-coated glass substrates and covered by CdS or ZnO thin films, for application in solar cells, have been characterized by spectroscopic ellipsometry, atomic force microscopy, photoluminescence and photovoltaic response. Computer aided simulations of the photovoltaic operation of these structures have been made to reinforce and complement the results of the characterization studies. The

  13. Phase transition and high temperature thermoelectric properties of copper selenide Cu2-xSe (0 <= x <= 0.25)

    NASA Astrophysics Data System (ADS)

    Xiao, Xing-Xing; Xie, Wen-Jie; Tang, Xin-Feng; Zhang, Qing-Jie

    2011-08-01

    With good electrical properties and an inherently complex crystal structure, Cu2-xSe is a potential “phonon glass electron crystal" thermoelectric material that has previously not attracted much interest. In this study, Cu2-xSe (0 <= x <= 0.25) compounds were synthesized by a melting-quenching method, and then sintered by spark plasma sintering to obtain bulk material. The effect of Cu content on the phase transition and thermoelectric properties of Cu2-xSe were investigated in the temperature range of 300 K-750 K. The results of X-ray diffraction at room temperature show that Cu2-xSe compounds possess a cubic structure with a space group of Fm3m(#225) when 0.15 <= x <= 0.25, whereas they adopt a composite of monoclinic and cubic phases when 0 <= x <= 0.15. The thermoelectric property measurements show that with increasing Cu content, the electrical conductivity decreases, the Seebeck coefficient increases and the thermal conductivity decreases. Due to the relatively good power factor and low thermal conductivity, the nearly stoichiometric Cu2Se compound achieves the highest ZT of 0.38 at 750 K. It is expected that the thermoelectric performance can be further optimized by doping appropriate elements and/or via a nanostructuring approach.

  14. Copper and Copper Proteins in Parkinson's Disease

    PubMed Central

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

    2014-01-01

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

  15. Copper Data Center Database

    NSDL National Science Digital Library

    Copper Development Association

    The Copper Data Center Database is provided free of charge by the Copper Development Association "to increase knowledge and awareness of copper, related technologies, and the role of copper in the environment." The database is an online bibliographic search engine of literature on copper, copper alloys and copper technology dating back to 1965 and is described as covering copper technology from smelting and hydrometallurgy through the performance of copper and copper alloys in their end-use applications and service environments. Users can search by standard methods including using keywords and titles or an impressive advanced search feature is also available. Although full text listings are not available, anyone interested in related subjects will appreciate this well designed and unique tool.

  16. NMR investigation of iron-selenide and iron-arsenide high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Imai, Takashi

    2012-02-01

    We have investigated the electronic, magnetic, and superconducting properties of the iron-selenide high Tc superconductor KxFe2-ySez (Tc=33 K) with ^77Se NMR [1]. We will compare the results with those observed for FeSe in ambient and applied pressures (Tc>9 K) [2], and with iron-arsenides [3]. Similarities and dissimilarities will be pointed out, with primary focus on the anomalous normal state properties. Our latest work on KxFe2-ySez was carried out in collaboration with D. Torchetti, M. Fu, D. Christensen, K. Nelson (McMaster), H. Lei, and C. Petrovic (Brookhaven National Lab).[4pt] [1] D. Torchetti et al., PR B83, 104508 (2011).[0pt] [2] T. Imai et al. PRL 102, 177005 (2009).[0pt] [3] F.L. Ning et al., PRL 104, 037001 (2010); JPSJ 78, 103711 (2009).

  17. Optoelectronic and low temperature thermoelectric studies on nanostructured thin films of silver gallium selenide

    NASA Astrophysics Data System (ADS)

    Jacob, Rajani; Philip, Rachel Reena; Nazer, Sheeba; Abraham, Anitha; Nair, Sinitha B.; Pradeep, B.; Urmila, K. S.; Okram, G. S.

    2014-01-01

    Polycrystalline thin films of silver gallium selenide were deposited on ultrasonically cleaned soda lime glass substrates by multi-source vacuum co-evaporation technique. The structural analysis done by X-ray diffraction ascertained the formation of nano structured tetragonal chalcopyrite thin films. The compound formation was confirmed by X-ray photo-electron spectroscopy. Atomic force microscopic technique has been used for surface morphological analysis. Direct allowed band gap ˜1.78eV with high absorption coefficient ˜106/m was estimated from absorbance spectra. Low temperature thermoelectric effects has been investigated in the temperature range 80-330K which manifested an unusual increase in Seebeck coefficient with negligible phonon drag toward the very low and room temperature regime. The electrical resistivity of these n-type films was assessed to be ˜2.6?m and the films showed good photo response.

  18. Preparation of cadmium selenide-polyolefin composites from functional phosphine oxides and ruthenium-based metathesis.

    PubMed

    Skaff, Habib; Ilker, M Firat; Coughlin, E Bryan; Emrick, Todd

    2002-05-22

    Cadmium selenide nanoparticles, prepared by known methods, were stabilized with functional phosphine oxide 1, then used to support the polymerization of cyclic olefins radially outward from the surface by ruthenium-catalyzed ring-opening metathesis polymerization (ROMP). The conversion of compound 1 into the new metathesis catalyst 3 by carbene exchange and the subsequent polymerization of cyclic olefins were observed spectroscopically by (1)H NMR to afford for example CdSe-polycyclooctene composite 6. Transmission electron micrographs on thin films of these composites showed good nanoparticle dispersion. This is in stark contrast to the substantial nanoparticle aggregation observed when similar polymerizations were performed in the presence of conventional TOPO-covered nanoparticles. The methods reported here to prepare composite product 6 are applicable to other cyclic olefins, and suggest that this chemistry will be useful for incorporating CdSe nanoparticles into a wide variety of polymer matrices. PMID:12010046

  19. First-principles theory of electron-spin fluctuation coupling and superconducting instabilities in iron selenide

    NASA Astrophysics Data System (ADS)

    Lischner, Johannes; Bazhirov, Timur; MacDonald, Allan H.; Cohen, Marvin L.; Louie, Steven G.

    2015-03-01

    We present first-principles calculations of the coupling of quasiparticles to spin fluctuations in iron selenide and discuss which types of superconducting instabilities this coupling gives rise to. We find that strong antiferromagnetic stripe-phase spin fluctuations lead to large coupling constants for superconducting gaps with s +/- -symmetry, but these coupling constants are significantly reduced by other spin fluctuations with small wave vectors. An accurate description of this competition and an inclusion of band structure and Stoner parameter renormalization effects lead to a value of the coupling constant for an s +/- symmetric gap which can produce a superconducting transition temperature consistent with experimental measurements. This work was supported by NSF Grant No. DMR10-1006184 and by DOE under Contract No. DE-AC02-05CH11231. Computational resources have been provided by the DOE at NERSC.

  20. Neutron diffraction studies of the negative thermal expansion in a layered indium selenide crystal

    NASA Astrophysics Data System (ADS)

    Dmitriev, A. I.; Kaminski?, V. M.; Lashkarev, G. V.; Butorin, P. E.; Kovalyuk, Z. D.; Ivanov, V. I.; Beskrovny?, A. I.

    2009-11-01

    The neutron diffraction patterns have been analyzed for a layered single crystal and a powder of the ?-polytype of indium selenide in the temperature range 10-300 K. In the temperature range 10-50 K, the excitation of bending vibrations due to the charge density waves changes the phonon spectrum and gives rise to a negative thermal expansion in the plane of layers, i.e., ?? c = -2.2 × 10-6 K-1, which is characteristic of two-dimensional structures. The average (over the range T = 50-300 K) coefficients of thermal expansion along the principal crystallographic directions have been calculated: bar ? _{ bot c} = 10.48 × 10-6 K-1 and bar ? _{allel c} = 12.97 × 10-6 K-1, which agree with the X-ray diffraction data previously obtained by the authors at T = 290 K.

  1. Nanoscale determination of the mass enhancement factor in the lightly doped bulk insulator lead selenide

    NASA Astrophysics Data System (ADS)

    Zeljkovic, Ilija; Scipioni, Kane L.; Walkup, Daniel; Okada, Yoshinori; Zhou, Wenwen; Sankar, R.; Chang, Guoqing; Wang, Yung Jui; Lin, Hsin; Bansil, Arun; Chou, Fangcheng; Wang, Ziqiang; Madhavan, Vidya

    2015-03-01

    Bismuth chalcogenides and lead telluride/selenide alloys exhibit exceptional thermoelectric properties that could be harnessed for power generation and device applications. Since phonons play a significant role in achieving these desired properties, quantifying the interaction between phonons and electrons, which is encoded in the Eliashberg function of a material, is of immense importance. However, its precise extraction has in part been limited due to the lack of local experimental probes. Here we construct a method to directly extract the Eliashberg function using Landau level spectroscopy, and demonstrate its applicability to lightly doped thermoelectric bulk insulator PbSe. In addition to its high energy resolution only limited by thermal broadening, this novel experimental method could be used to detect variations in mass enhancement factor at the nanoscale level. This opens up a new pathway for investigating the local effects of doping and strain on the mass enhancement factor.

  2. Nanoscale determination of the mass enhancement factor in the lightly doped bulk insulator lead selenide.

    PubMed

    Zeljkovic, Ilija; Scipioni, Kane L; Walkup, Daniel; Okada, Yoshinori; Zhou, Wenwen; Sankar, R; Chang, Guoqing; Wang, Yung Jui; Lin, Hsin; Bansil, Arun; Chou, Fangcheng; Wang, Ziqiang; Madhavan, Vidya

    2015-01-01

    Bismuth chalcogenides and lead telluride/selenide alloys exhibit exceptional thermoelectric properties that could be harnessed for power generation and device applications. Since phonons play a significant role in achieving these desired properties, quantifying the interaction between phonons and electrons, which is encoded in the Eliashberg function of a material, is of immense importance. However, its precise extraction has in part been limited due to the lack of local experimental probes. Here we construct a method to directly extract the Eliashberg function using Landau level spectroscopy, and demonstrate its applicability to lightly doped thermoelectric bulk insulator PbSe. In addition to its high energy resolution only limited by thermal broadening, this novel experimental method could be used to detect variations in mass enhancement factor at the nanoscale level. This opens up a new pathway for investigating the local effects of doping and strain on the mass enhancement factor. PMID:25814140

  3. Dynamic observation of phase transformation behaviors in indium(III) selenide nanowire based phase change memory.

    PubMed

    Huang, Yu-Ting; Huang, Chun-Wei; Chen, Jui-Yuan; Ting, Yi-Hsin; Lu, Kuo-Chang; Chueh, Yu-Lun; Wu, Wen-Wei

    2014-09-23

    Phase change random access memory (PCRAM) has been extensively investigated for its potential applications in next-generation nonvolatile memory. In this study, indium(III) selenide (In2Se3) was selected due to its high resistivity ratio and lower programming current. Au/In2Se3-nanowire/Au phase change memory devices were fabricated and measured systematically in an in situ transmission electron microscope to perform a RESET/SET process under pulsed and dc voltage swept mode, respectively. During the switching, we observed the dynamic evolution of the phase transformation process. The switching behavior resulted from crystalline/amorphous change and revealed that a long pulse width would induce the amorphous or polycrystalline state by different pulse amplitudes, supporting the improvement of the writing speed, retention, and endurance of PCRAM. PMID:25133955

  4. Nanoscale determination of the mass enhancement factor in the lightly doped bulk insulator lead selenide

    PubMed Central

    Zeljkovic, Ilija; Scipioni, Kane L.; Walkup, Daniel; Okada, Yoshinori; Zhou, Wenwen; Sankar, R; Chang, Guoqing; Wang, Yung Jui; Lin, Hsin; Bansil, Arun; Chou, Fangcheng; Wang, Ziqiang; Madhavan, Vidya

    2015-01-01

    Bismuth chalcogenides and lead telluride/selenide alloys exhibit exceptional thermoelectric properties that could be harnessed for power generation and device applications. Since phonons play a significant role in achieving these desired properties, quantifying the interaction between phonons and electrons, which is encoded in the Eliashberg function of a material, is of immense importance. However, its precise extraction has in part been limited due to the lack of local experimental probes. Here we construct a method to directly extract the Eliashberg function using Landau level spectroscopy, and demonstrate its applicability to lightly doped thermoelectric bulk insulator PbSe. In addition to its high energy resolution only limited by thermal broadening, this novel experimental method could be used to detect variations in mass enhancement factor at the nanoscale level. This opens up a new pathway for investigating the local effects of doping and strain on the mass enhancement factor. PMID:25814140

  5. Silica encapsulation of thiol-stabilized lead selenide (PbSe) quantum dots in aqueous solution

    PubMed Central

    Primera-Pedrozo, Oliva M.; Ates, Mehmet; Arslan, Zikri

    2013-01-01

    Silica encapsulation of lead selenide quantum dots (PbSe QDs) in aqueous solution is reported. Thioglycolic acid (TGA) stabilized PbSe QDs were modified with 3-mercaptopropyl trimethoxysilane (MPS) through vigorous stirring in water for 18–24 h in alkaline solution (pH 10.4–10.6). Silica shell was developed by controlled deposition and precipitation of silicates from sodium silicate solution onto MPS modified QDs surfaces. TEM images showed multiple PbSe QDs encapsulated in silica shell. The size of PbSe-SiO2 core-shell nanocrystals was estimated to be 25–30 nm by TEM. Elemental compositions (Pb, Se and Si) were investigated by EDX analysis. The purified colloids of PbSe-SiO2 QDs were stable for months when kept at 4 °C. PMID:23729944

  6. Structural complexity in indium selenides prepared using bicyclic amines as structure-directing agents.

    PubMed

    Ewing, S J; Vaqueiro, P

    2015-01-28

    The synthesis and characterization of five new indium selenides, [C9H17N2]3[In5Se(8+x)(Se2)(1-x)] (1-2), [C6H12N2]4[C6H14N2]3[In10Se15(Se2)3] (3), [C6H14N2][(C6H12N2)2NaIn5Se9] (4) and [enH2][NH4][In7Se12] (5), are described. These materials were prepared under solvothermal conditions, using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,4-diazabicyclo[2.2.2]octane (DABCO) as structure-directing agents. Compounds 1-4 represent the first examples of ribbons in indium selenides, and 4 is the first example of incorporation of an alkali metal complex. Compounds 1, 2 and 4 contain closely related [In5Se(8+x)(Se2)(1-x)](3-) ribbons which differ only in their content of (Se2)(2-) anions. These ribbons are interspaced by organic countercations in 1 and 2, while in 4 they are linked by highly unusual [Na(DABCO)2](+) units into a three-dimensional framework. Compound 3 contains complex ribbons, with a long repeating sequence of ca. 36 Å, and 4 is a non-centrosymmetric three-dimensional framework, formed as a consequence of the decomposition of DABCO into ethylenediamine (en) and ammonia. PMID:25426726

  7. Growth kinetics and photoelectrochemical (PEC) performance of cadmium selenide thin films: pH and substrate effect

    Microsoft Academic Search

    Y. G. Gudage; Ramphal Sharma

    2010-01-01

    Cadmium selenide (CdSe) thin films have been electrochemically deposited on the stainless steel (SS) and fluorine-doped tin oxide (FTO) coated glass substrates at room temperature (27°C). The growth kinetics of CdSe thin films was studied by using cyclic voltammetry and chronoamperometry with variation in the pH of the electrolytic bath. In addition, the influence of the substrate on the microstructural

  8. Copper-tantalum alloy

    DOEpatents

    Schmidt, Frederick A. (Ames, IA); Verhoeven, John D. (Ames, IA); Gibson, Edwin D. (Ames, IA)

    1986-07-15

    A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

  9. Copper associated childhood cirrhosis

    Microsoft Academic Search

    S P Horslen; M S Tanner; T D Lyon; G S Fell; M F Lowry

    1994-01-01

    Several papers have reported severe liver disease in association with massive hepatic copper accumulation, which do not seem to be either of the recognised copper associated liver diseases, namely Wilson's disease and Indian childhood cirrhosis. A further case is reported in which novel copper kinetic studies were carried out using the stable isotope 65Cu, showing that this patient did not

  10. Laser induced copper plating

    Microsoft Academic Search

    A. K. Al-Sufi; H. J. Eichler; J. Salk; H. J. Riedel

    1983-01-01

    Argon laser induced plating of copper spots and lines from copper sulfate solutions on glass and phenolic resin paper has been investigated. The substrates had to be precoated with an evaporated copper film. The highest plating rates have been obtained with a small film thickness of 25 nm. Spots with a thickness up to 30 ?m were plated.

  11. COPPER DEFICIENCY PROPHYLAXIS IN GRAZING SHEEP BY COPPER OXIDE INJECTION

    E-print Network

    Boyer, Edmond

    COPPER DEFICIENCY PROPHYLAXIS IN GRAZING SHEEP BY COPPER OXIDE INJECTION M. LAMAND Claudine LAB R of insoluble and non ionized form of injected copper has been shown in a previous paper (Lamand, 1978 it appeared that copper oxide was preferable to metallic copper, being slightly less caustic. Inflammation

  12. Efficient solution-processed small molecule: Cadmium selenide quantum dot bulk heterojunction solar cells

    SciTech Connect

    Gupta, Vinay, E-mail: drvinaygupta@netscape.net [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India) [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India); Department of Physics, University of California, Santa Barbara, California 93106 (United States); Upreti, Tanvi; Chand, Suresh [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India)] [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India)

    2013-12-16

    We report bulk heterojunction solar cells based on blends of solution-processed small molecule [7,7?-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b?]dithiophene-2,6-diyl) bis(6-fluoro-4-(5?-hexyl-[2,2?-bithiophen]-5yl)benzo[c] [1,2,5] thiadiazole)] p-DTS(FBTTh{sub 2}){sub 2}: Cadmium Selenide (CdSe) (70:30, 60:40, 50:50, and 40:60) in the device configuration: Indium Tin Oxide /poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/p-DTS(FBTTh{sub 2}){sub 2}: CdSe/Ca/Al. The optimized ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe::60:40 leads to a short circuit current density (J{sub sc})?=?5.45?mA/cm{sup 2}, open circuit voltage (V{sub oc})?=?0.727?V, and fill factor (FF)?=?51%, and a power conversion efficiency?=?2.02% at 100 mW/cm{sup 2} under AM1.5G illumination. The J{sub sc} and FF are sensitive to the ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe, which is a crucial factor for the device performance.

  13. Bifacial dye-sensitized solar cells with transparent cobalt selenide alloy counter electrodes

    NASA Astrophysics Data System (ADS)

    Duan, Yanyan; Tang, Qunwei; He, Benlin; Zhao, Zhiyuan; Zhu, Ling; Yu, Liangmin

    2015-06-01

    High power conversion efficiency and cost-effectiveness are two persistent objectives for dye-sensitized solar cell (DSSC). Electricity generation from either front or rear side of a bifacial DSSC has been considered as a facile avenue of bringing down the cost of solar-to-electric conversion. Therefore, the fabrication of a transparent counter electrode (CE) with a high electrocatalytic activity is a prerequisite to realize this goal. We present here the feasibility of utilizing transparent cobalt selenide (Co-Se) binary alloy counter electrode for bifacial DSSC application, in which binary Co-Se alloy electrode is synthesized by a mild solution strategy and the cell device is irradiated by either front or rear side. Due to the high optical transparency, charge-transfer ability, and electrocatalytic activity, maximum front and rear efficiencies of 8.30% and 4.63% are recorded under simulated air mass 1.5 (AM1.5) irradiation, respectively. The impressive efficiency along with fast start-up, multiple start capability, and simple preparation highlights the potential application of cost-effective and transparent Co-Se alloy CE in robust bifacial DSSCs.

  14. Development of bismuth tellurium selenide nanoparticles for thermoelectric applications via a chemical synthetic process

    SciTech Connect

    Kim, Cham [Daegu Gyeongbuk Institute of Science and Technology (DGIST), 711-623 Hosan-dong, Dalseo-gu, Daegu 704-230 (Korea, Republic of) [Daegu Gyeongbuk Institute of Science and Technology (DGIST), 711-623 Hosan-dong, Dalseo-gu, Daegu 704-230 (Korea, Republic of); Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784 (Korea, Republic of); Kim, Dong Hwan; Han, Yoon Soo [Daegu Gyeongbuk Institute of Science and Technology (DGIST), 711-623 Hosan-dong, Dalseo-gu, Daegu 704-230 (Korea, Republic of)] [Daegu Gyeongbuk Institute of Science and Technology (DGIST), 711-623 Hosan-dong, Dalseo-gu, Daegu 704-230 (Korea, Republic of); Chung, Jong Shik [Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784 (Korea, Republic of)] [Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784 (Korea, Republic of); Park, SangHa [Daegu Machinery Institute of Components and Materials (DMI), 12 Horim-dong, Dalseo-gu, Daegu 704-240 (Korea, Republic of)] [Daegu Machinery Institute of Components and Materials (DMI), 12 Horim-dong, Dalseo-gu, Daegu 704-240 (Korea, Republic of); Park, Soonheum [Department of Nanomaterial Chemistry, Dongguk University, Seokjang-dong, Gyeongju, Gyeongbuk 780-714 (Korea, Republic of)] [Department of Nanomaterial Chemistry, Dongguk University, Seokjang-dong, Gyeongju, Gyeongbuk 780-714 (Korea, Republic of); Kim, Hoyoung, E-mail: hoykim@dgist.ac.kr [Daegu Gyeongbuk Institute of Science and Technology (DGIST), 711-623 Hosan-dong, Dalseo-gu, Daegu 704-230 (Korea, Republic of)] [Daegu Gyeongbuk Institute of Science and Technology (DGIST), 711-623 Hosan-dong, Dalseo-gu, Daegu 704-230 (Korea, Republic of)

    2011-03-15

    Research highlights: {yields} We synthesized a Bi{sub 2}Te{sub y}Se{sub 3-y} nano-compound via a chemical synthetic process. {yields} The compound was sintered to achieve an average grain size of about 300 nm. {yields} The resulting sintered body showed very low thermal conductivity. It is likely caused by the vigorous phonon scattering of the nano-sized grains. -- Abstract: Bismuth tellurium selenide (Bi{sub 2}Te{sub y}Se{sub 3-y}) nanoparticles for thermoelectric applications are successfully prepared via a water-based chemical reaction under atmospheric conditions. The nanostructured compound is prepared using a complexing agent (ethylenediaminetetraacetic acid) and a reducing agent (ascorbic acid) to stabilize the bismuth precursor (Bi(NO{sub 3}){sub 3}) in water and to favor the reaction with reduced sources of tellurium and selenium. The resulting powder is smaller than ca. 100 nm and has a crystalline structure corresponding to the rhombohedral Bi{sub 2}Te{sub 2.7}Se{sub 0.3}. The nanocrystalline powder is sintered via a spark plasma sintering process to obtain a sintered body composed of nano-sized grains. Important transport properties of the sintered body are measured to calculate its most important characteristic, the thermoelectric performance. The results demonstrate a relationship between the nanostructure of the sintered body and its thermal conductivity.

  15. Revealing the Preferred Interlayer Orientations and Stackings of Two-Dimensional Bilayer Gallium Selenide Crystals

    SciTech Connect

    Li, Xufan [ORNL; Basile Carrasco, Leonardo A [ORNL; Yoon, Mina [ORNL; Ma, Cheng [ORNL; Puretzky, Alexander A [ORNL; Lee, Jaekwang [ORNL; Idrobo Tapia, Juan Carlos [ORNL; Chi, Miaofang [ORNL; Rouleau, Christopher M [ORNL; Geohegan, David B [ORNL; Xiao, Kai [ORNL

    2015-01-01

    Characterizing and controlling the interlayer orientations and stacking order of bilayer two-dimensional (2D) crystals and van der Waals (vdW) heterostructure is crucial to optimize their electrical and optoelectronic properties. The four polymorphs of layered gallium selenide (GaSe) that result from different layer stacking provide an ideal platform to study the stacking configurations in bilayer 2D crystals. Here, through a controllable vapor-phase deposition method we selectively grow bilayer GaSe crystals and investigate their two preferred 0 or 60 interlayer rotations. The commensurate stacking configurations (AA and AB-stacking) in as-grown 2D bilayer GaSe crystals are clearly observed at the atomic scale and the Ga-terminated edge structure are identified for the first time by using atomic-resolution scanning transmission electron microscopy (STEM). Theoretical analysis of the interlayer coupling energetics vs. interlayer rotation angle reveals that the experimentally-observed orientations are energetically preferred among the bilayer GaSe crystal polytypes. The combined experimental and theoretical characterization of the GaSe bilayers afforded by these growth studies provide a pathway to reveal the atomistic relationships in interlayer orientations responsible for the electronic and optical properties of bilayer 2D crystals and vdW heterostructures.

  16. Ultrafast Charge- and Energy-Transfer Dynamics in Conjugated Polymer: Cadmium Selenide Nanocrystal Blends

    PubMed Central

    2014-01-01

    Hybrid nanocrystal–polymer systems are promising candidates for photovoltaic applications, but the processes controlling charge generation are poorly understood. Here, we disentangle the energy- and charge-transfer processes occurring in a model system based on blends of cadmium selenide nanocrystals (CdSe-NC) with poly[2-methoxy-5-(3?,7?-dimethyloctyloxy)-1,4-phenylene vinylene] (MDMO-PPV) using a combination of time-resolved absorption and luminescence measurements. The use of different capping ligands (n-butylamine, oleic acid) as well as thermal annealing allows tuning of the polymer–nanocrystal interaction. We demonstrate that energy transfer from MDMO-PPV to CdSe-NCs is the dominant exciton quenching mechanism in nonannealed blends and occurs on ultrafast time scales (<1 ps). Upon thermal annealing electron transfer becomes competitive with energy transfer, with a transfer rate of 800 fs independent of the choice of the ligand. Interestingly, we find hole transfer to be much less efficient than electron transfer and to extend over several nanoseconds. Our results emphasize the importance of tuning the organic–nanocrystal interaction to achieve efficient charge separation and highlight the unfavorable hole-transfer dynamics in these blends. PMID:24490650

  17. Dry autoclaving for the nanofabrication of sulfides, selenides, borides, phosphides, nitrides, carbides, and oxides.

    PubMed

    Pol, Vilas G; Pol, Swati V; Gedanken, Aharon

    2011-03-11

    This review compiles various nanostructures fabricated by a distinct "dry autoclaving" approach, where the chemical reactions are carried out without solvents; above the dissociation temperature of the chemical precursor(s) at elevated temperature in a closed reactor. The diversity to fabricate carbides (SiC, Mo(2) C, WC), oxides (VOx-C, ZnO, Eu(2) O(3) , Fe(3) O(4) , MoO(2) ), hexaborides (LaB(6) , CeB(6) , NdB(6) , SmB(6) , EuB(6) , GdB(6) ), nitrides (TiN, NbN, TaN), phosphides (PtP(2) , WP), sulfides (ZnS, FeS/C, SnS/C, WS(2) , WS(2) /C), and selenides (Zn(1-x) Mn(x) Se/C, Cd(1-x) Mn(x) Se/C), with various shapes and sizes is accounted with plausible applications. This unique single-step, solvent-free synthetic process opens up a new route in the growing nanomaterials science; owing to its considerable advantages on the existing approaches. PMID:20803759

  18. Chemical deposition of bismuth selenide thin films using N,N-dimethylselenourea

    NASA Astrophysics Data System (ADS)

    García, V. M.; Nair, M. T. S.; Nair, P. K.; Zingaro, R. A.

    1997-05-01

    Good quality thin films of bismuth selenide of thickness up to 0268-1242/12/5/020/img7 were deposited from solutions containing bismuth nitrate, triethanolamine and N,N-dimethylselenourea maintained at temperatures ranging from room temperature to 0268-1242/12/5/020/img8. X-ray diffraction patterns of the samples annealed at 0268-1242/12/5/020/img9 in air match the standard pattern of hexagonal 0268-1242/12/5/020/img10 (paraguanajuatite, JCPDS 33-0214). The films exhibit strong optical absorption corresponding to a bandgap of about 1.7 - 1.41 eV in the as-prepared films. These values decrease to about 1.57 - 1.06 eV upon annealing the films at 0268-1242/12/5/020/img9 for 1 h in nitrogen. As-deposited, the films show high sheet resistance 0268-1242/12/5/020/img12 in the dark. Annealing the films in air or in nitrogen enhances the dark current by about seven orders of magnitude; the resulting dark conductivity is about 0268-1242/12/5/020/img13. This enhancement in conductivity results from improved crystallinity as well as from partial loss of selenium.

  19. Topological insulator bismuth selenide as a theranostic platform for simultaneous cancer imaging and therapy.

    PubMed

    Li, Juan; Jiang, Fei; Yang, Bo; Song, Xiao-Rong; Liu, Yan; Yang, Huang-Hao; Cao, Dai-Rong; Shi, Wen-Rong; Chen, Guo-Nan

    2013-01-01

    Employing theranostic nanoparticles, which combine both therapeutic and diagnostic capabilities in one dose, has promise to propel the biomedical field toward personalized medicine. Here we investigate the theranostic properties of topological insulator bismuth selenide (Bi2Se3) in in vivo and in vitro system for the first time. We show that Bi2Se3 nanoplates can absorb near-infrared (NIR) laser light and effectively convert laser energy into heat. Such photothermal conversion property may be due to the unique physical properties of topological insulators. Furthermore, localized and irreversible photothermal ablation of tumors in the mouse model is successfully achieved by using Bi2Se3 nanoplates and NIR laser irradiation. In addition, we also demonstrate that Bi2Se3 nanoplates exhibit strong X-ray attenuation and can be utilized for enhanced X-ray computed tomography imaging of tumor tissue in vivo. This study highlights Bi2Se3 nanoplates could serve as a promising platform for cancer diagnosis and therapy. PMID:23770650

  20. Biogenic nanoparticles: copper, copper oxides, copper sulphides, complex copper nanostructures and their applications.

    PubMed

    Rubilar, Olga; Rai, Mahendra; Tortella, Gonzalo; Diez, Maria Cristina; Seabra, Amedea B; Durán, Nelson

    2013-09-01

    Copper nanoparticles have been the focus of intensive study due to their potential applications in diverse fields including biomedicine, electronics, and optics. Copper-based nanostructured materials have been used in conductive films, lubrification, nanofluids, catalysis, and also as potent antimicrobial agent. The biogenic synthesis of metallic nanostructured nanoparticles is considered to be a green and eco-friendly technology since neither harmful chemicals nor high temperatures are involved in the process. The present review discusses the synthesis of copper nanostructured nanoparticles by bacteria, fungi, and plant extracts, showing that biogenic synthesis is an economically feasible, simple and non-polluting process. Applications for biogenic copper nanoparticles are also discussed. PMID:23690046

  1. High adherence copper plating process

    DOEpatents

    Nignardot, Henry (Tesuque, NM)

    1993-01-01

    A process for applying copper to a substrate of aluminum or steel by electrodeposition and for preparing an aluminum or steel substrate for electrodeposition of copper. Practice of the invention provides good adhesion of the copper layer to the substrate.

  2. Copper-containing zeolite catalysts

    DOEpatents

    Price, Geoffrey L. (Baton Rouge, LA); Kanazirev, Vladislav (Sofia, BG)

    1996-01-01

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl.sub.2, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  3. Copper-containing zeolite catalysts

    DOEpatents

    Price, G.L.; Kanazirev, V.

    1996-12-10

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, is formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl{sub 2}, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  4. Redox control of GPx catalytic activity through mediating self-assembly of Fmoc-phenylalanine selenide into switchable supramolecular architectures.

    PubMed

    Huang, Zupeng; Luo, Quan; Guan, Shuwen; Gao, Jianxiong; Wang, Yongguo; Zhang, Bo; Wang, Liang; Xu, Jiayun; Dong, Zeyuan; Liu, Junqiu

    2014-12-28

    Artificial enzymes capable of achieving tunable catalytic activity through stimuli control of enzymatic structure transition are of significance in biosensor and biomedicine research. Herein we report a novel smart glutathione peroxidise (GPx) mimic with modulatory catalytic activity based on redox-induced supramolecular self-assembly. First, an amphiphilic Fmoc-phenylalanine-based selenide was designed and synthesized, which can self-assemble into nanospheres (NSs) in aqueous solution. The NSs demonstrate extremely low GPx activity. Upon the oxidation of hydroperoxides (ROOH), the selenide can be quickly transformed into the selenoxide form. The change of the molecular structure induces complete morphology transition of the self-assemblies from NSs to nanotubes (NTs), resulting in great enhancement in the GPx catalytic activity. Under the reduction of GSH, the selenoxide can be further reversibly reduced back into the selenide; therefore the reversible switch between the NSs and NTs can be successfully accomplished. The relationship between the catalytic activity and enzymatic structure was also investigated. The dual response nature makes this mimic play roles of both a sensor and a GPx enzyme at the same time, which can auto-detect the signal of ROOH and then auto-change its activity to achieve quick or slow/no scavenging of ROOH. The dynamic balance of ROOH is vital in organisms, in which an appropriate amount of ROOH does benefit to the metabolism, whereas surplus ROOH can cause oxidative damage of the cell instead and this smart mimic is of remarkable significance. We expect that such a mimic can be developed into an effective antioxidant drug and provide a new platform for the construction of intelligent artificial enzymes with multiple desirable properties. PMID:25366375

  5. Copper Delivery by Metallochaperone Proteins

    SciTech Connect

    Rosenzweig, A.C. (NWU)

    2010-03-08

    Copper is an essential element in all living organisms, serving as a cofactor for many important proteins and enzymes. Metallochaperone proteins deliver copper ions to specific physiological partners by direct protein-protein interactions. The Atx1-like chaperones transfer copper to intracellular copper transporters, and the CCS chaperones shuttle copper to copper,zinc superoxide dismutase. Crystallographic studies of these two copper chaperone families have provided insights into metal binding and target recognition by metallochaperones and have led to detailed molecular models for the copper transfer mechanism.

  6. Pulsed copper halide vapor lasers

    NASA Astrophysics Data System (ADS)

    Kazarian, M. A.; Petrash, G. G.; Trofimov, A. N.

    The theory and the performance characteristics of copper halide lasers are examined with reference to recent theoretical and experimental research in the field of metal vapor lasers. The discussion covers gas discharge tubes, comparative characteristics of copper halide lasers, determination of the metastable level decomposition rates in copper chloride and copper bromide lasers, and spectroscopic measurements of the discharge plasma in copper halide lasers. Attention is also given to the kinetics of copper atoms formation in copper halide lasers and calculation of the kinetic characteristics of copper halide lasers.

  7. Investigation of Second- and Third-Harmonic Generation in Few-Layer Gallium Selenide by Multiphoton Microscopy

    PubMed Central

    Karvonen, Lasse; Säynätjoki, Antti; Mehravar, Soroush; Rodriguez, Raul D.; Hartmann, Susanne; Zahn, Dietrich R. T.; Honkanen, Seppo; Norwood, Robert A.; Peyghambarian, N.; Kieu, Khanh; Lipsanen, Harri; Riikonen, Juha

    2015-01-01

    Gallium selenide (GaSe) is a layered semiconductor and a well-known nonlinear optical crystal. The discovery of graphene has created a new vast research field focusing on two-dimensional materials. We report on the nonlinear optical properties of few-layer GaSe using multiphoton microscopy. Both second- and third-harmonic generation from few-layer GaSe flakes were observed. Unexpectedly, even the peak at the wavelength of 390?nm, corresponding to the fourth-harmonic generation or the sum frequency generation from third-harmonic generation and pump light, was detected during the spectral measurements in thin GaSe flakes. PMID:25989113

  8. Investigation of second- and third-harmonic generation in few-layer gallium selenide by multiphoton microscopy.

    PubMed

    Karvonen, Lasse; Säynätjoki, Antti; Mehravar, Soroush; Rodriguez, Raul D; Hartmann, Susanne; Zahn, Dietrich R T; Honkanen, Seppo; Norwood, Robert A; Peyghambarian, N; Kieu, Khanh; Lipsanen, Harri; Riikonen, Juha

    2015-01-01

    Gallium selenide (GaSe) is a layered semiconductor and a well-known nonlinear optical crystal. The discovery of graphene has created a new vast research field focusing on two-dimensional materials. We report on the nonlinear optical properties of few-layer GaSe using multiphoton microscopy. Both second- and third-harmonic generation from few-layer GaSe flakes were observed. Unexpectedly, even the peak at the wavelength of 390?nm, corresponding to the fourth-harmonic generation or the sum frequency generation from third-harmonic generation and pump light, was detected during the spectral measurements in thin GaSe flakes. PMID:25989113

  9. Refractories for Copper Production

    Microsoft Academic Search

    MARK E. SCHLESINGER

    1996-01-01

    The furnaces used for producing molten copper from concentrates and scrap - flash: smelters, converters, and anode and fire-refining furnaces - present a unique combination of challenges to refractory life. Highly aggressive slags, mechanical stresses, batch operation, and increasingly higher operating temperatures all combine to destroy most refractory materials. Over the past generation, copper producers have adopted refractory materials biased

  10. Ions Sputtered from Copper

    Microsoft Academic Search

    R. C. Bradley; E. Ruedl

    1962-01-01

    Positive ions sputtered from copper under a variety of different bombardment and surface conditions have been mass analyzed and found to include species characteristic of the incident ions (``reflected'' ions), of copper and some of its compounds, and of alkali metal impurities. A model is described which accounts for most of the properties of the ``reflected'' ions, not in terms

  11. Bioaccessibility and Solubility of Copper in Copper-Treated Lumber

    EPA Science Inventory

    Micronized copper (MC)-treated lumber is a recent replacement for Chromated Copper Arsenate (CCA) and Ammonium Copper (AC)-treated lumbers; though little is known about the potential risk of copper (Cu) exposure from incidental ingestion of MC-treated wood. The bioaccessibility o...

  12. Reduction of selenate to selenide by sulfate-respiring bacteria: Experiments with cell suspensions and estuarine sediments

    USGS Publications Warehouse

    Zehr, J.P.; Oremland, R.S.

    1987-01-01

    Washed cell suspension of Desulfovibrio desulfuricans subsp. aestuarii were capable of reducing nanomolar levels of selenate to selenide as well as sulfate to sulfide. Reduction of these species was inhibited by 1 mM selenate or tungstate. The addition of 1 mM sulfate decreased the reduction of selenate and enhanced the reduction of sulfate. Increasing concentrations of sulfate inhibited rates of selenate reduction but enhanced sulfate reduction rates. Cell suspensions kept in 1 mM selenate were incapable of reducing either selenate or sulfate when the selenate/sulfate ratio was ???0.02, indicating that irreversible inhibition occurs at high selenate concentrations. Anoxic estuarine sediments having an active flora of sulfate-respiring bacteria were capable of a small amount of selenate reduction when ambient sulfate concentrations were low (<4 mM). These results indicate that sulfate is an inhibitor of the reduction of trace qunatitites of selenate. Therefore, direct reduction of traces of selenate to selenide by sulfate-respiring bacteria in natural environments is constrained by the ambient concentration of sulfate ions. The significance of this observation with regard to the role sediments play in sequestering selenium is discussed.

  13. Physical and Mechanical Properties of Copper and Copper Alloys

    Microsoft Academic Search

    Meimei Li; Steven J Zinkle

    2012-01-01

    High strength, high conductivity copper alloys are prime candidates for high heat flux applications in fusion energy systems. This chapter reviews the physical and mechanical properties of pure copper and copper alloys with the focus on precipitation-hardened CuCrZr and dispersion-strengthened CuAl25 alloys. The effect of neutron irradiation on copper and copper alloys is reviewed in terms of radiation effects on

  14. Copper sensitivity of Gonyaulax tamarensis

    Microsoft Academic Search

    D. M. Anderson; F. M. M. Morel

    1978-01-01

    The copper sensitivity of the dinoflagellate Gonyaulax tamarensis was examined in artificial seawater medium. Two short term responses of the organism to copper toxicity are rapid loss of motility and reduced photosynthetic carbon fixation. The chelators tris(hydroxymethylamino)methane (Tris) and ethylenedinitrilotetraacetic acid (EDTA) were used to demonstrate that copper toxicity is a unique function of cupric ion activity. Copper additions to

  15. Ammonia-rich high-temperature superconducting intercalates of iron selenide revealed through time-resolved in situ X-ray and neutron diffraction.

    PubMed

    Sedlmaier, Stefan J; Cassidy, Simon J; Morris, Richard G; Drakopoulos, Michael; Reinhard, Christina; Moorhouse, Saul J; O'Hare, Dermot; Manuel, Pascal; Khalyavin, Dmitry; Clarke, Simon J

    2014-01-15

    The development of a technique for following in situ the reactions of solids with alkali metal/ammonia solutions, using time-resolved X-ray diffraction methods, reveals high-temperature superconducting ammonia-rich intercalates of iron selenide which reversibly absorb and desorb ammonia around ambient temperatures. PMID:24354523

  16. Influence of thermal annealing in air on the electro-optic characteristics of chemical bath deposited non-stoichiometric cadmium zinc selenide thin films

    Microsoft Academic Search

    K. C. Sharma; J. C. Garg

    1990-01-01

    Non-stoichiometric thin films of cadmium zinc selenide were grown onto glass substrates by the chemical bath deposition technique from elemental selenium, sodium sulphite, cadmium chloride, zinc chloride, deionised water and ammonia. As-deposited films were annealed at different temperatures up to 600 K. From their deposition temperature in air, their electrical conductivity, optical properties and microstructure were evaluated. The electrical conductivity

  17. Superconducting Phases in Potassium-Intercalated Iron Selenides Tianping Ying, Xiaolong Chen,* Gang Wang,* Shifeng Jin, Xiaofang Lai, Tingting Zhou, Han Zhang,

    E-print Network

    Wang, Wei Hua

    Superconducting Phases in Potassium-Intercalated Iron Selenides Tianping Ying, Xiaolong Chen,* Gang two pure SC phases, KxFe2Se2(NH3)y (x 0.3 and 0.6), determined mainly by potassium concentration.84(1) Å. With higher potassium doping, the 44 K phase can be converted into the 30 K phase. NH3 has little

  18. COPPER CABLE RECYCLING TECHNOLOGY

    SciTech Connect

    Chelsea Hubbard

    2001-05-01

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D&D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D&D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D&D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D&D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness of separating out radioactive contamination, the copper cable was coated with a surrogate contaminant. The demonstration took place at the Bonneville County Technology Center in Idaho Falls, Idaho.

  19. Fabricating Copper Nanotubes by Electrodeposition

    NASA Technical Reports Server (NTRS)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  20. Volatility of copper

    SciTech Connect

    Palmer, D.A.; Simonson, J.M.; Joyce, D.B.

    1996-08-01

    The relevant aqueous thermodynamics of copper and its oxides are evaluated and summarized with emphasis on solubility, hydrolysis, and complexation. The solubilities of metallic copper, solid cuprous and cupric oxides in steam measured by Pocock and Stewart in 1963 are discussed and the latter data are fitted in the form of established empirical equations and compared to other existing results. No other sources of data were found for the solubility of copper and cupric oxide in steam and even these data are very limited. Discussion of corresponding available solubility data on both oxide phases in liquid water is given. The possible effects of complexing agents are considered. A brief discussion is provided of the role of surface adsorption in determining the fate of dissolved copper in the boiler. 37 refs., 5 figs., 3 tabs.

  1. Canine models of copper toxicosis for understanding mammalian copper metabolism.

    PubMed

    Fieten, Hille; Leegwater, Peter A J; Watson, Adrian L; Rothuizen, Jan

    2012-02-01

    Hereditary forms of copper toxicosis exist in man and dogs. In man, Wilson's disease is the best studied disorder of copper overload, resulting from mutations in the gene coding for the copper transporter ATP7B. Forms of copper toxicosis for which no causal gene is known yet are recognized as well, often in young children. Although advances have been made in unraveling the genetic background of disorders of copper metabolism in man, many questions regarding disease mechanisms and copper homeostasis remain unanswered. Genetic studies in the Bedlington terrier, a dog breed affected with copper toxicosis, identified COMMD1, a gene that was previously unknown to be involved in copper metabolism. Besides the Bedlington terrier, a number of other dog breeds suffer from hereditary copper toxicosis and show similar phenotypes to humans with copper storage disorders. Unlike the heterogeneity of most human populations, the genetic structure within a purebred dog population is homogeneous, which is advantageous for unraveling the molecular genetics of complex diseases. This article reviews the work that has been done on the Bedlington terrier, summarizes what was learned from studies into COMMD1 function, describes hereditary copper toxicosis phenotypes in other dog breeds, and discusses the opportunities for genome-wide association studies on copper toxicosis in the dog to contribute to the understanding of mammalian copper metabolism and copper metabolism disorders in man. PMID:22147205

  2. Bacterial Killing by Dry Metallic Copper Surfaces?

    PubMed Central

    Santo, Christophe Espírito; Lam, Ee Wen; Elowsky, Christian G.; Quaranta, Davide; Domaille, Dylan W.; Chang, Christopher J.; Grass, Gregor

    2011-01-01

    Metallic copper surfaces rapidly and efficiently kill bacteria. Cells exposed to copper surfaces accumulated large amounts of copper ions, and this copper uptake was faster from dry copper than from moist copper. Cells suffered extensive membrane damage within minutes of exposure to dry copper. Further, cells removed from copper showed loss of cell integrity. Acute contact with metallic copper surfaces did not result in increased mutation rates or DNA lesions. These findings are important first steps for revealing the molecular sensitive targets in cells lethally challenged by exposure to copper surfaces and provide a scientific explanation for the use of copper surfaces as antimicrobial agents for supporting public hygiene. PMID:21148701

  3. Electronic structure and Fermi surface of new K intercalated iron selenide superconductor K xFe 2Se 2

    NASA Astrophysics Data System (ADS)

    Shein, I. R.; Ivanovskii, A. L.

    2011-02-01

    Using the ab initio FLAPW-GGA method we examine the electronic band structure, densities of states, and the Fermi surface topology for a very recently synthesized ThCr2Si2-type potassium intercalated iron selenide superconductor KxFe2Se2. We found that the electronic state of the stoichiometric KFe2Se2 is far from that of the isostructural iron pnictide superconductors. Thus the main factor responsible for experimentally observed superconductivity for this material is the deficiency of potassium, i.e. the hole doping effect. On the other hand, based on the results obtained, we conclude that the tuning of the electronic system of the new KxFe2Se2 superconductor in the presence of K vacancies is achieved by joint effect owing to structural relaxations and hole doping, where the structural factor is responsible for the modification of the band topology, whereas the doping level determines their filling.

  4. Electrical Transport and Grain Growth in Solution-Cast, Chloride-Terminated Cadmium Selenide Nanocrystal Thin Films

    PubMed Central

    2015-01-01

    We report the evolution of electrical transport and grain size during the sintering of thin films spin-cast from soluble phosphine and amine-bound, chloride-terminated cadmium selenide nanocrystals. Sintering of the nanocrystals occurs in three distinct stages as the annealing temperature is increased: (1) reversible desorption of the organic ligands (?150 °C), (2) irreversible particle fusion (200–300 °C), and (3) ripening of the grains to >5 nm domains (>200 °C). Grain growth occurs at 200 °C in films with 8 atom % Cl–, while films with 3 atom % Cl– resist growth until 300 °C. Fused nanocrystalline thin films (grain size = 4.5–5.5 nm) on thermally grown silicon dioxide gate dielectrics produce field-effect transistors with electron mobilities as high as 25 cm2/(Vs) and on/off ratios of 105 with less than 0.5 V hysteresis in threshold voltage without the addition of indium. PMID:24960255

  5. Role of copper transporters in copper homeostasis234

    PubMed Central

    Prohaska, Joseph R

    2009-01-01

    Copper is a redox active metal that is essential for biological function. Copper is potentially toxic; thus, its homeostasis is carefully regulated through a system of protein transporters. Copper is taken up across the lumen surface of the small intestinal microvilli as cuprous ion by Ctr1. Cupric ion may also be taken up, but those processes are less well understood. Within the cell, intestinal as well as others, copper is escorted to specific compartments by metallo-chaperones. One, CCS, donates copper to superoxide dismutase. Another, COX17, delivers copper to additional chaperones within the mitochondria for synthesis of cytochrome c oxidase. A third chaperone, Atox1, delivers copper to the secretory pathway by docking with 2 P-type ATPases. One, ATP7A, is the protein nonfunctional in Menkes disease. This protein is required for cuproenzyme biosynthesis, and in the enterocyte it is required for copper efflux to portal blood. The second, ATP7B, predominantly expressed in liver, is required for copper metallation of ceruloplasmin and biliary copper excretion. Mutations in ATP7B lead to Wilson disease. Additional intracellular hepatic copper-binding proteins COMMD1 (copper metabolism MURR1 domain) and XIAP (X-linked inhibitor of apoptosis protein) may also be required for excretion. Other proteins involved in copper homeostasis may include metallothionein and amyloid precursor protein. Plasma protein transport of copper from the intestine to liver and in systemic circulation probably includes both albumin and ?2-macroglobulin. Changes in the expression of copper “transporters” may be useful to monitor copper status of humans, provided a suitable cell type can be sampled. PMID:18779302

  6. Desorption process of copper chlorides from copper surface

    Microsoft Academic Search

    Atsushi Hibi; Akio Susa; Mitsuo Koshi

    2008-01-01

    Gaseous copper chlorides can be employed as precursors in a newly developed Cu-CVD method called metal chloride reduction-chemical vapor deposition (MCR-CVD). More than one species exists in the gas phase of copper chloride. We studied the gas phase composition of copper chlorides generated by etching of copper surface by electron impact-mass spectrometry. The composition of gaseous species can change because

  7. Optoelectronic characteristics of inorganic/organic hybrid device based on poly(N-vinylcarbazole)/ cadmium selenide thin films.

    PubMed

    Tang, Aiwei; Teng, Feng; Hou, Yanbing; Xiong, Sha; Feng, Bin; Qian, Lei; Wang, Yongsheng

    2008-03-01

    Inorganic/organic hybrid light-emitting diodes were easily fabricated with a thin film containing water-soluble cadmium selenide nanocrystals and poly(N-vinylcarbazole) as an emitting layer by a spin-coating method. The cadmium selenide nanocrystals were synthesized in aqueous solution with L-cysteine hydrochloride as the stabilizer and were transferred from the aqueous solution into chloroform by a cationic surfactant cetyltrimethyl ammonium bromide. A broad emission spanning the whole visible wavelength range was obtained from the inorganic/organic hybrid devices whether poly(N-vinylcarbazole) was present in the devices or not, and the electroluminescence intensity of the devices increased as the applied voltages increased. However, an obvious blue-shift of the wavelength was observed with the increasing applied voltages in the device with poly(N-vinylcarbazole). Accordingly, the emission color of the device made with poly(N-vinylcarbazole) could be tuned from white to blue by varying the applied voltages, but the emission color of the device made without poly(N-vinylcarbazole) was almost constrained in the white region. This can be attributed to a limited contribution of poly(N-vinylcarbazole) emission to the electroluminescence spectra under the higher applied voltage. By comparing the electroluminescence intensity and the current-voltage characteristics of the devices made with and without poly(N-vinylcarbazole), the performance of the device with poly(N-vinylcarbazole) was improved greatly, which indicated that poly(N-vinylcarbazole) played an important role in the carrier injection and transportation in the device with poly(N-vinylcarbazole). PMID:18468148

  8. LABORATORY EXPERIMENT 7 Determination of Copper in Copper Alloys

    E-print Network

    Nazarenko, Alexander

    LABORATORY EXPERIMENT 7 Determination of Copper in Copper Alloys Two procedures for Cu determination in the same alloy sample will be used. Both are based on Cu2+ reduction. I. The Electrogravimetric Determination of Copper in Alloy A convenient example of an electrogravimetric method of analysis

  9. Ceruloplasmin, copper ions, and angiogenesis.

    PubMed

    Raju, K S; Alessandri, G; Ziche, M; Gullino, P M

    1982-11-01

    The ability to induce new formation of capillaries in the cornea was tested for ceruloplasmin, the copper carrier of serum, for fragments of the ceruloplasmin molecule with and without copper, for heparin, and for glycyl-L-histidyl-L-lysine, bound or not bound to copper ions. Male or female 2- to 3-kg New Zealand White rabbits were used. These experiments were prompted by the previous observation of copper accumulation in the cornea during angiogenesis and by the inability of copper-deficient rabbits to mount an angiogenic response. The results showed that the three different molecules were all able to induce angiogenesis provided that they were bound to copper. Fragments of the ceruloplasmin molecule also induced angiogenesis but only when copper was bound to the peptides. The data are interpreted to indicate that copper ions are involved in the sequence of events leading to angiogenesis and that the carrier molecules may be of quite a different nature. PMID:6182332

  10. Exploring for Copper Deposits

    NSDL National Science Digital Library

    2007-02-11

    In this activity, students assume the role of a geologist prospecting for copper deposits. From the background material, they will learn what ore deposits are and some important factors in their origin; and learn about a type of ore deposit known as a porphyry copper deposit. They will plot data from a table onto maps and use a geologic map, a soil geochemistry map, and a sediment geochemistry map to help locate the porphyry copper deposit. As a result of this activity, the students will be able to calculate an ore grade and determine whether or not an ore deposit is economically profitable based on its grade, size, and production costs. Worksheets and data tables are included.

  11. Agricultural soils spiked with copper mine wastes and copper concentrate: implications for copper bioavailability and bioaccumulation.

    PubMed

    Ginocchio, Rosanna; Sánchez, Pablo; de la Fuente, Luz María; Camus, Isabel; Bustamante, Elena; Silva, Yasna; Urrestarazu, Paola; Torres, Juan C; Rodríguez, Patricio H

    2006-03-01

    A better understanding of exposure to and effects of copper-rich pollutants in soils is required for accurate environmental risk assessment of copper. A greenhouse experiment was conducted to study copper bioavailability and bioaccumulation in agricultural soils spiked with different types of copper-rich mine solid wastes (copper ore, tailing sand, smelter dust, and smelter slag) and copper concentrate. A copper salt (copper sulfate, CuSO4) that frequently is used to assess soil copper bioavailability and phytotoxicity also was included for comparison. Results showed that smelter dust, tailing sand, and CuSO4 are more likely to be bioavailable and, thus, toxic to plants compared with smelter slag, concentrate, and ore at equivalent total copper concentrations. Differences may be explained by intrinsic differences in copper solubilization from the source materials, but also by their capability to decrease soil pH (confounding effect). The copper toxicity and bioaccumulation in plants also varied according to soil physicochemical characteristics (e.g., pH and total organic carbon) and the available levels of plant nutrients, such as nitrogen, phosphorus, and potassium. Chemistry/mineralogy of mine materials, soil/pore-water chemistry, and plant physiological status thus should be integrated for building adequate models to predict phytotoxicity and environmental risk of copper. PMID:16566155

  12. December 200 Copper Acquisition by

    E-print Network

    Fischlin, Andreas

    December 200 Copper Acquisition by Methanotrophic Bacteria 7 Term Paper HS2007 Major. One is soluble in the cytoplasm and the other is bound to the membrane. Since the expression of copper containing pMMO depends on copper availability it is supposed that some methanotrophs have developed

  13. HEALTH MATTERS Copper T IUD

    E-print Network

    Yener, Aylin

    T IUD? · This is a highly effective type of birth control. · The Copper T IUD does not contain hormones or interact with medicines. · You don't have to think about birth control every day or every time you have sex expensive methods of birth control. What are the downsides of using the Copper T IUD? · The Copper T IUD

  14. SOURCES OF COPPER AIR EMISSIONS

    EPA Science Inventory

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

  15. Zinc sulfide and zinc selenide immersion gratings for astronomical high-resolution spectroscopy: evaluation of internal attenuation of bulk materials in the short near-infrared region

    Microsoft Academic Search

    Yuji Ikeda; Naoto Kobayashi; Sohei Kondo; Chikako Yasui; Paul J. Kuzmenko; Hitoshi Tokoro; Hiroshi Terada

    2009-01-01

    We measure the internal attenuation of bulk crystals of chemical vapor deposition zinc selenide (CVD-ZnS), chemical vapor deposition zinc sulfide (CVD-ZnSe), Si, and GaAs in the short near-infrared (sNIR) region to evaluate the possibility of astronomical immersion gratings with those high refractive index materials. We confirm that multispectral grade CVD-ZnS and CVD-ZnSe are best suited for the immersion gratings, with

  16. Hohenheim Consensus Workshop: Copper

    Microsoft Academic Search

    K Schümann; HG Classen; HH Dieter; J König; G Multhaup; M Rükgauer; KH Summer; J Bernhardt; HK Biesalski

    2002-01-01

    Copper (Cu) is an essential trace element with many physiological functions. Homeostatic mechanisms exist to allow Cu to act as a cofactor in enzymatic processes and to prevent accumulation of Cu to toxic levels. The aim of this commentary is to better understand the role of dietary Cu supply in deficiency and under physiological and pathological conditions. The essentiality of

  17. Earth's anthrobiogeochemical copper cycle

    Microsoft Academic Search

    J. N. Rauch; T. E. Graedel

    2007-01-01

    An “anthrobiogeochemical” copper cycle, from Earth's core to the Moon, combining natural biogeochemical and human anthropogenic stocks and flows is derived for the mid-1990s. Although some aspects of the quantification have moderate to high uncertainty, the anthropogenic mining, manufacturing, and use flows (on the order of 104 Gg Cu\\/yr) clearly dominate the cycle. In contrast, the natural repositories of Earth's

  18. Creative Copper Crests

    ERIC Educational Resources Information Center

    Knab, Thomas

    2011-01-01

    In this article, the author discusses how to create an art activity that would link the computer-created business cards of fourth-grade students with an upcoming school-wide medieval event. Creating family crests from copper foil would be a great connection, since they, like business cards, are an individual's way to identify themselves to others.…

  19. Superhydrophobic Copper Surfaces

    NSDL National Science Digital Library

    This lesson from The Lawrence Hall of Science was taught in fall 2012 and focuses on superhydrophobic and superhydrophilic surfaces. Students will experiment with these materials by chemically modifying copper. This page includes links to the Source Article for the Hands-on Module as well as four documents for instructor use in teaching the lab.

  20. Effects of ring size and polar functional groups on the glutathione peroxidase-like antioxidant activity of water-soluble cyclic selenides.

    PubMed

    Arai, Kenta; Kumakura, Fumio; Takahira, Motoi; Sekiyama, Natsumi; Kuroda, Nozomi; Suzuki, Toshiki; Iwaoka, Michio

    2015-06-01

    To elucidate the effects of ring structure and a substituent on the glutathione peroxidase- (GPx-) like antioxidant activities of aliphatic selenides, series of water-soluble cyclic selenides with variable ring size and polar functional groups were synthesized, and their antioxidant activities were evaluated by NADPH-coupled assay using H2O2 and glutathione (GSH) in water and also by NMR spectroscopy using H2O2 and dithiothreitol (DTT(red)) in methanol. Strong correlations were found among the GPx-like activity in water, the second-order rate constants for the oxidation of the selenides, and the HOMO energy levels calculated in water. The results support the conclusion that the oxidation process is the rate-determining step of the catalytic cycle. On the other hand, such correlations were not obtained for the activity observed in methanol. The optimal ring size was determined to be five. The type of substituent (NH2 < OH < CO2H) and the number can also control the activity, whereas the stereoconfiguration has only marginal effects on the activity in water. In methanol, however, the activity rank could not be explained by the simple scenarios applicable in water. PMID:25941977

  1. Traps identification in Copper-Indium-Gallium-Sulfur-Selenide Solar Cells Completed with Various Buffer Layers by Deep Level Transient Spectroscopy

    SciTech Connect

    Kundu, Sambhu N.; Johnston , Steve; Olsen, Larry C.

    2006-12-05

    Current-voltage characteristics of thin film semiconductor devices are greatly affected by surface and interface defects. Deep level transient spectroscopy (DLTS) has been used in this work to reveal information about defect levels in CuInGaSSe based solar cells. The defect spectra varied significantly from sample to sample. Majority and minority carrier traps were identified for each cell. An effort was made to correlate the traps with the chemical nature of defects. In particular, cells were investigated that had three different buffer layers namely CdS, ZnO and ZnS. In the case of ZnO and ZnS buffer layer devices cells with high and low efficiencies were studied. The lower efficiency cells were characterized by deeper trap levels. PACS: 84.60.Jt; 71.20.Nr

  2. Traps identification in Copper-Indium-Gallium-Sulfur-Selenide solar cells completed with various buffer layers by deep level transient spectroscopy

    Microsoft Academic Search

    Sambhu N. Kundu; Steve Johnston; Larry C. Olsen

    2006-01-01

    Current–voltage characteristics of thin-film semiconductor devices are greatly affected by surface and interface defects. Deep level transient spectroscopy has been used in this work to reveal information about defect levels in CuInGaSSe based solar cells. The defect spectra varied significantly from sample to sample. Majority and minority carrier traps were identified for each cell. An effort was made to correlate

  3. The effect of silicon and copper-indium-gallium-selenide based solar cell structures and processing on temperature dependent performance losses

    NASA Astrophysics Data System (ADS)

    Hsieh, Judith

    Temperature dependent current voltage measurements (J-V-T) of solar cells. provide both fundamental and practical information. They give detailed insight into. recombination losses within the device as well as information about module. performance losses at higher outdoor operating temperatures. In this thesis, J-V-T. measurements were applied to two distinctly different types of solar cells: crystalline. silicon heterojunction cells and thin film (AgCu)(InGa)Se2 or ACIGS polycrystalline. cells. Crystalline silicon solar cells with heterojunction structure improve the opencircuit. voltage and efficiency. Interdigitated back contact (IBC) Si solar cells obtain a. higher short-circuit current and fill factor compared to front heterojunction (FHJ) solar. cells. ACIGS solar cells have shown higher efficiencies at wider bandgap compared to. the baseline CIGS solar cells. Two high open-circuit voltage CIGS solar cells are. included and compared with ACIGS solar cells. In this thesis, the impact of different. types of solar cells structure and fabrication on temperature dependent performance. losses will be discussed. Devices with higher bandgap are predicted to have higher. open-circuit voltage and lower temperature coefficient of maximum power output. (Pmax). The correlation between temperature coefficient of Pmax and open-circuit. voltage can be found in Si FHJ cells but not Si IBC or ACIGS cells. However, ACIGS. cells show an inverse correlation between temperature coefficient of Pmax and bandgap. as expected. Analysis of diode quality factor and other parameters are interpreted. Sshape. J-V curve can reduce the device's fill factor with a relative high series resistance. This phenomenon tends to occur in FHJ cells rather than IBC at low temperature. Light-dark crossover and roll over effects are commonly seen in ACIGS cells and the. anomaly is enhanced at lower temperature. Most of FHJ and IBC cells obtain the. ideality factor between 1 and 2 while some of ACIGS cells obtain the ideality factor. less than 1 or larger than 2. The value of the ideality factor may be limited by different. recombination mechanism.

  4. 21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125...CERTIFICATION Drugs § 73.1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper...

  5. 21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125...CERTIFICATION Drugs § 73.1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper...

  6. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125... Cosmetics § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper...

  7. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125... Cosmetics § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper...

  8. 21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125...CERTIFICATION Drugs § 73.1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper...

  9. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125... Cosmetics § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper...

  10. 21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125...CERTIFICATION Drugs § 73.1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper...

  11. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125... Cosmetics § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper...

  12. 21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125...CERTIFICATION Drugs § 73.1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper...

  13. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125... Cosmetics § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper...

  14. Fate of copper in ponds.

    PubMed

    McIntosh, A W

    1975-03-01

    Treatments of 3 ppm copper sulfate (CuSO4-5H2O) were applied to two small aquatic systems in Michigan in 1971. To study the pathways of the added copper, samples of water, sediment, aquatic macrophytes, filamentous algae, and fish were collected and analyzed by atomic absorption. Sampling was initiated before treatment and continued up to 4 months in one of the ponds. Dissolved copper concentrations in water decreased rapidly immediately after treatment and then gradually to background levels. Reduction of dissolved copper may have involved initial precipitation of an insoluble compound, such as malachite, followed by sediment adsorption of soluble copper complexes and copper released from aquatic plants. Levels of copper in sediment increased rapidly at first and gradually later in the study. Aquatic plants and filamentous algae accumulated very high levels of copper. Uptake rates were apparently affected by water temperature and growth stages of the plants. Data indicate that aquatic macrophytes developing in one pond 10 weeks after treatment took up copper from the sediment. Although green sunfish (Lepomis cyanellus) accumulated copper soon after treatment, levels returned to background later in the study. PMID:1161446

  15. Evolutionary aspects of copper binding centers in copper proteins

    Microsoft Academic Search

    B. Abolmaali; H. Taylor; U. Weser

    A great number of active centers in proteins and enzymes contain transition metals. Each metal imposes specific catalytic\\u000a properties on the protein which could not be achieved when employing a different metal. The special role and characteristic\\u000a reactivity of icoordinated copper is illustrated by looking at the evolutionary aspects of copper proteins. The evolution\\u000a of copper-binding sites is closely linked

  16. Use of 64copper measurements to diagnose canine copper toxicosis.

    PubMed

    Brewer, G J; Schall, W; Dick, R; Yuzbasiyan-Gurkan, V; Thomas, M; Padgett, G

    1992-01-01

    Inherited canine copper toxicosis is a serious problem in Bedlington terriers and West Highland White terriers, and may also be a problem in other less-studied breeds. Affected dogs become ill at midlife with progressive and ultimately fatal liver disease. Treatments for removal of copper and prevention of copper accumulation are available, but are most effective if begun before the dog becomes ill. Until recently diagnosis has not been available until the dog is 1 year of age, and then only by an invasive liver biopsy with determination of liver copper concentration. The authors studied the use of 64copper for early diagnosis of canine copper toxicosis. Two procedures were evaluated. The first involved measuring the concentration of 64copper in blood 24 hours after oral administration of the radioisotope. At this time, 64copper was associated primarily with ceruloplasmin secreted into the blood by the liver. This procedure is useful in the diagnosis of the human counterpart, Wilson's disease. However, the authors found it to be nondiscriminatory between affected and unaffected dogs. In contrast, the second procedure, which involved measuring 64copper excreted in stool during 48 hours after an intravenous dose of radioisotope, yielded results that differentiated most affected and unaffected dogs. PMID:1548626

  17. Chronic Copper Poisoning in Sheep. 

    E-print Network

    Boughton, I. B. (Ivan Bertrand); Hardy, W. T. (William Tyree)

    1934-01-01

    LIBRARY, - A & M COLLEGE, CAiQFUS. E-109-8M-L180 TEXAS AGRICULTURAL EXPERIMENT STATION A. B. CONNER, DIRECTOR COLLEGE STATION: BRAZOS COUNTY. TEXAS BULLETIN NO. 499 DECEMBER, 1934 DIVISION OF VETERINARY SCIENCE CHRONIC COPPER POISONING... of copper sulphate caused chronic copper poisoning among flocks of range sheep on several West Texas ranches during the past year. The salt licks were placed before the sheep as a means of preventing or controlling stomach worm infestation despite a...

  18. A new mixed group 5 metal selenide, Nb1.41V0.59Se9

    PubMed Central

    Lee, Eunsil; Yun, Hoseop

    2011-01-01

    The new mixed-metallic phase, niobium vanadium nona­selenide, (Nb2-xVx)Se9 (0.18? x ? 0.59) is isostructural with monoclinic V2Se9. The structure is composed of chains of bicapped trigonal–prismatic [MSe8] units. The metal (M) site is occupied by statistically disordered Nb [0.706?(5)] and V [0.294?(5)] atoms. Two trigonal prisms are linked by sharing a recta­ngular face composed of two Se2 2? pairs. Through three edging and capping Se atoms, the chains are extended along [101]. The chain shows alternating short [2.8847?(7)?Å] and long [3.7159?(7)?Å] M—M distances. The structure shows a wide range of Se—Se inter­actions. In addition to the Se2 2? pairs of the recta­ngular face, an inter­mediate Se?Se separation [2.6584?(5)?Å] is found. The amount of each metal can vary, [(Nb2-xVx)Se9, 0.18 ? x ?m 0.59] and they seem to form a random substitutional solid solution. The M—M distances increase gradually by increasing the amount of Nb atoms. The classical charge-balance of the compound can be described as [M 4+]2[Se2 2?]2[Se5 4?]. PMID:22064790

  19. Reduction of elemental selenium to selenide: Experiments with anoxic sediments and bacteria that respire Se-oxyanions

    USGS Publications Warehouse

    Herbel, M.J.; Blum, J.S.; Oremland, R.S.; Borglin, S.E.

    2003-01-01

    A selenite-respiring bacterium, Bacillus selenitireducens, produced significant levels of Se(-II) (as aqueous HSe-) when supplied with Se(O). B. selenitireducens was also able to reduce selenite [Se(IV)] through Se(O) to Se(-II). Reduction of Se(O) by B.selenitireducens was more rapid in cells grown on colloidal sulfur [S(O)] or Se(IV) as their electron acceptor than for cell lines grown on fumarate. In contrast, three cultures of selenate-respiring bacteria, Sulfurospirillum barnesii, B. arsenicoselenatis, and Selenihalanaerobacter shriftii either were unable to reduce Se(O) to Se(-II) or had only a very limited capacity to achieve this reduction. Biological reduction of Se(O) to Se(-II) was observed during incubation of estuarine sediment slurries, while no such activity was noted in formalin-killed controls. The majority of the Se(-II) produced was found in the sediments as a solid precipitate of FeSe, rather than in solution as HSe-. These results demonstrate that certain anaerobic bacteria have the capacity to reduce Se(O) to Se(-II), providing a possible biological explanation for the occurrence of the selenide species in some sedimentary rocks.

  20. Growth and thermoelectric properties of multilayer thin film of bismuth telluride and indium selenide via rf magnetron sputtering.

    PubMed

    Kim, Hyo-Jung; Kim, Kwang-Chon; Choi, Won Chel; Kim, Jin-Sang; Kim, Young-Hwan; Kim, Seong Il; Park, Chan

    2012-04-01

    A bismuth telluride (BT)/indium selenide (IS) multilayer film was deposited at room temperature by rf magnetron sputtering on a sapphire substrate in order to investigate how the multilayered structure affects the microstructure and thermoelectric properties. The effect of annealing at different temperatures was also studied. The results were compared with those from a BT film with the same thickness. A TEM study showed that the interface between the BT and IS layers became vague as the annealing temperature increased, and the BT layer crystallized while the IS layer did not. The presence of thin IS layers can help to limit the evaporation of Te from the BT/IS multilayer film, thus increasing the amount of Bi2Te3 phase in the multilayer film as compared with that of the BT film. An abrupt increase in the Seebeck coefficient of the multilayer film was observed when annealed at 300 degrees C, and the resistivity of the annealed multilayer film was high compared to that of the BT film. This result can also be explained by the proposed role of the IS layer, which limits the evaporation of Te at high temperature. The highest power factor of -3.9 x 10(-6) W/K2 cm was obtained at room temperature from the multilayer film annealed at 300 degrees C. PMID:22849183

  1. Effect of an iodine-containing additive on the composition, structure, and morphology of chemically deposited lead selenide films

    NASA Astrophysics Data System (ADS)

    Smirnova, Z. I.; Bakanov, V. M.; Maskaeva, L. N.; Markov, V. F.; Voronin, V. I.

    2014-12-01

    The effect of an ammonium iodide additive on the elemental and phase compositions, structural parameters, and surface morphology of lead selenide films synthesized by chemical deposition from aqueous solutions has been studied using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analysis. It has been established that the obtained PbSe films have a multiphase structure. The iodine content of the films is directly proportional to the NH4I concentration in the reaction mixture and increases linearly with an increase in this concentration to 0.25 mol/L. No individual iodine-containing phases have been detected in the film structure. However, the introduction of iodine leads to an increase in the PbSe phase lattice parameter from ˜6.11 to ˜6.16 Å and to a decrease in the crystal grain size to ˜ 20 nm. It has been found that there is a correlation between the grain size, lattice parameter, and ammonium iodide concentration in the reaction mixture, which can be explained by changes in the film growth mechanism at the initial growth steps.

  2. Electrical and optical characteristics of heterojunction devices composed of silicon nanowires and mercury selenide nanoparticle films on flexible plastics.

    PubMed

    Yeo, Minje; Yun, Junggwon; Kim, Sangsig

    2013-09-01

    A pn heterojunction device based on p-type silicon (Si) nanowires (NWs) prepared by top-down method and n-type mercury selenide (HgSe) nanoparticles (NPs) synthesized by the colloidal method have been fabricated on a flexible plastic substrate. The synthesized HgSe NPs were analyzed through the effective mass approximation. The characteristics of the heterojunction device were examined and studied with the energy band diagram. The device showed typical diode characteristics with a turn-on voltage of 1.5 V and exhibited a high rectification ratio of 10(3) under relatively low forward bias. Under illumination of 633-nm-wavelength light, the device presented photocurrent efficiency of 117.5 and 20.1 nA/W under forward bias and reverse bias conditions, respectively. Moreover, the photocurrent characteristics of the device have been determined by bending of the plastic substrate upward and downward with strain of 0.8%. Even though the photocurrent efficiency has fluctuations during the bending cycles, the values are roughly maintained for 10(4) bending cycles. This result indicates that the fabricated heterojunction device has the potential to be applied as fundamental elements of flexible nanoelectronics. PMID:24205678

  3. Preparation of few-layer bismuth selenide by liquid-phase-exfoliation and its optical absorption properties.

    PubMed

    Sun, Liping; Lin, Zhiqin; Peng, Jian; Weng, Jian; Huang, Yizhong; Luo, Zhengqian

    2014-01-01

    Bismuth selenide (Bi2Se3), a new topological insulator, has attracted much attention in recent years owing to its relatively simple band structure and large bulk band gap. Compared to bulk, few-layer Bi2Se3 is recently considered as a highly promising material. Here, we use a liquid-phase exfoliation method to prepare few-layer Bi2Se3 in N-methyl-2-pyrrolidone or chitosan acetic solution. The resulted few-layer Bi2Se3 dispersion demonstrates an interesting absorption in the visible light region, which is different from bulk Bi2Se3 without any absorption in this region. The absorption spectrum of few-layer Bi2Se3 depends on its size and layer number. At the same time, the nonlinear and saturable absorption of few-layer Bi2Se3 thin film in near infrared is also characterized well and further exploited to generate laser pulses by a passive Q-switching technique. Stable Q-switched operation is achieved with a lower pump threshold of 9.3?mW at 974?nm, pulse energy of 39.8?nJ and a wide range of pulse-repetition-rate from 6.2 to 40.1?kHz. Therefore, the few-layer Bi2Se3 may excite a potential applications in laser photonics and optoelectronic devices. PMID:24762534

  4. Preparation of Few-Layer Bismuth Selenide by Liquid-Phase-Exfoliation and Its Optical Absorption Properties

    PubMed Central

    Sun, Liping; Lin, Zhiqin; Peng, Jian; Weng, Jian; Huang, Yizhong; Luo, Zhengqian

    2014-01-01

    Bismuth selenide (Bi2Se3), a new topological insulator, has attracted much attention in recent years owing to its relatively simple band structure and large bulk band gap. Compared to bulk, few-layer Bi2Se3 is recently considered as a highly promising material. Here, we use a liquid-phase exfoliation method to prepare few-layer Bi2Se3 in N-methyl-2-pyrrolidone or chitosan acetic solution. The resulted few-layer Bi2Se3 dispersion demonstrates an interesting absorption in the visible light region, which is different from bulk Bi2Se3 without any absorption in this region. The absorption spectrum of few-layer Bi2Se3 depends on its size and layer number. At the same time, the nonlinear and saturable absorption of few-layer Bi2Se3 thin film in near infrared is also characterized well and further exploited to generate laser pulses by a passive Q-switching technique. Stable Q-switched operation is achieved with a lower pump threshold of 9.3?mW at 974?nm, pulse energy of 39.8?nJ and a wide range of pulse-repetition-rate from 6.2 to 40.1?kHz. Therefore, the few-layer Bi2Se3 may excite a potential applications in laser photonics and optoelectronic devices. PMID:24762534

  5. 21 CFR 73.2647 - Copper powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Copper powder. 73.2647 Section 73...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity...

  6. 21 CFR 73.2647 - Copper powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Copper powder. 73.2647 Section 73...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity...

  7. 21 CFR 73.2647 - Copper powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Copper powder. 73.2647 Section 73...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity...

  8. 21 CFR 73.2647 - Copper powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Copper powder. 73.2647 Section 73...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity...

  9. 21 CFR 73.2647 - Copper powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Copper powder. 73.2647 Section 73...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity...

  10. Removal of copper from ferrous scrap

    DOEpatents

    Blander, M.; Sinha, S.N.

    1990-05-15

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  11. Removal of copper from ferrous scrap

    DOEpatents

    Blander, M.; Sinha, S.N.

    1987-07-30

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  12. Removal of copper from ferrous scrap

    DOEpatents

    Blander, Milton (12833 S. 82nd Ct., Palos Park, IL 60464); Sinha, Shome N. (5748 Drexel, 2A, Chicago, IL 60637)

    1990-01-01

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  13. Copper and Copper Oxide Nanoparticle Formation by Chemical Vapor Nucleation From Copper (II) Acetylacetonate

    Microsoft Academic Search

    Albert G. Nasibulin; P. Petri Ahonen; Olivier Richard; Esko I. Kauppinen; Igor S. Altman

    2001-01-01

    Crystalline nanometer-size copper and copper (I) oxide particle formation was studied by thermal decomposition of copper acetylacetonate Cu(acac)2 vapor using a vertical flow reactor at ambient nitrogen pressure. The experiments were performed in the precursor vapor pressure range of Pprec = 0.06 to 44 Pa at furnace temperatures of 431.5°C, 596.0°C, and 705.0°C. Agglomerates of primary particles were formed at

  14. Solvent-controlled halo-selective selenylation of aryl halides catalyzed by Cu(II) supported on Al2O3. A general protocol for the synthesis of unsymmetrical organo mono- and bis-selenides.

    PubMed

    Chatterjee, Tanmay; Ranu, Brindaban C

    2013-07-19

    Alumina-supported Cu(II) efficiently catalyzes selenylation of aryl iodides and aryl bromides by diaryl, dialkyl, and diheteroaryl diselenides in water and PEG-600, respectively, leading to a general route toward synthesis of unsymmetrical diaryl, aryl-alkyl, aryl-heteroaryl, and diheteroaryl selenides. A sequential reaction of bromoiodobenzene with one diaryl/diheteroaryl/dialkyl diselenide in water and another diaryl/diheteroaryl/dialkyl diselenide in PEG-600 in the second step produces unsymmetrical diaryl, diheteroaryl, or aryl-alkyl bis-selanyl benzene. A library of functionalized organo mono- and bis-selenides, including a potent biologically active molecule and a couple of analogues of bioactive selenides, were obtained in high yields by this protocol. The reactions are chemoselective and high yielding. The Cu-Al2O3 catalyst is recycled for seven runs without any appreciable loss of activity. PMID:23786642

  15. Direct gold and copper wires bonding on copper

    Microsoft Academic Search

    Hong Meng Ho; Wai Lam; Serguei Stoukatch; Petar Ratchev; Charles J. Vath; Eric Beyne

    2003-01-01

    The key to bonding to copper die is to ensure bond pad cleanliness and minimum oxidation during wire bonding process. This has been achieved by applying a organic coating layer to protect the copper bond pad from oxidation. During the wire bonding process, the organic coating layer is removed and a metal to metal weld is formed. This organic layer

  16. Inborn errors of copper metabolism.

    PubMed

    Kaler, Stephen G

    2013-01-01

    Two copper-transporting ATPases are essential for mammalian copper homeostasis: ATP7A, which mediates copper uptake in the gastrointestinal tract and copper delivery to the brain, and ATP7B, which mediates copper excretion by the liver into bile. Mutations in ATP7A may cause three distinct X-linked conditions in infants, children, or adolescents: Menkes disease, occipital horn syndrome (OHS), and a newly identified allelic variant restricted to motor neurons called X-linked distal hereditary motor neuropathy. These three disorders show variable neurological findings and ages of onset. Menkes disease presents in the first several months of life with failure to thrive, developmental delay, and seizures. OHS features more subtle developmental delays, dysautonomia, and connective tissue abnormalities beginning in early childhood. ATP7A-related distal motor neuropathy presents even later, often not until adolescence or early adulthood, and involves a neurological phenotype that resembles Charcot-Marie-Tooth disease, type 2. These disorders may be treatable through copper replacement or ATP7A gene therapy. In contrast, mutations in ATP7B cause a single known phenotype, Wilson disease, an autosomal recessive trait that results from copper overload rather than deficiency. Dysarthria, dystonia, tremor, gait abnormalities, and psychiatric problems may be presenting symptoms, at ages from 10 to 40 years. Excellent treatment options exist for Wilson disease, based on copper chelation. In the past 2 years (2012-2013), three new autosomal recessive copper metabolism conditions have been recognized: 1) Huppke-Brendel syndrome caused by mutations in an acetyl CoA transporter needed for acetylation of one or more copper proteins, 2) CCS deficiency caused by mutations in the copper chaperone to SODI, and 3) MEDNIK syndrome, which revealed that mutations in the ?1A subunit of adaptor protein complex 1 (AP-1) have detrimental effects on trafficking of ATP7A and ATP7B. PMID:23622398

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

    SciTech Connect

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

    1995-12-31

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

  18. Minimizing iron and copper deposition

    Microsoft Academic Search

    1975-01-01

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

  19. Copper deficiency mimicking myelodysplastic syndrome

    PubMed Central

    Dalal, Neil; Hooberman, Arthur; Mariani, Rachel; Sirota, Ronald; Lestingi, Timothy

    2015-01-01

    Key Clinical Message Copper deficiency is a rare cause of pancytopenia that may be mistaken for myelodysplastic syndrome. Cytoplasmic vacuolization in erythroid and myeloid precursors is found on bone marrow examination. Patients with a history of abdominal surgery who present with anemia and neutropenia with dysplastic changes should have copper levels checked. PMID:25984314

  20. Copper Substrate Catalyzes Tetraazaperopyrene Polymerization

    E-print Network

    Schmidt, Wolf Gero

    Copper Substrate Catalyzes Tetraazaperopyrene Polymerization W.G. Schmidt, E. Rauls, U. Gerstmann-up approach, appears to be a very promising way to fabricate functional systems with nanometer dimensions [1 found that the copper substrate is crucial for the formation of the various aggregates they observed, i

  1. Advanced copper wire bonding technology

    Microsoft Academic Search

    Hong Meng Ho

    2010-01-01

    Wire bonding is the most dominant form of first-level chip interconnects in microelectronics with gold wire bonding taking the lead for the past few decades. Today, it is evident that the shift from gold to copper wire bonding is genuinely picking up, due to both a surge in gold prices and recent developments in copper wire bonding technology. The course

  2. The Work Function of Copper

    Microsoft Academic Search

    Paul A. Anderson

    1949-01-01

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

  3. Effects of copper(II) and copper oxides on THMs formation in copper pipe.

    PubMed

    Li, Bo; Qu, Jiuhui; Liu, Huijuan; Hu, Chengzhi

    2007-08-01

    Little is known about how the growth of trihalomethanes (THMs) in drinking water is affected in copper pipe. The formation of THMs and chlorine consumption in copper pipe under stagnant flow conditions were investigated. Experiments for the same water held in glass bottles were performed for comparison. Results showed that although THMs levels firstly increased in the presence of chlorine in copper pipe, faster decay of chlorine as compared to the glass bottle affected the rate of THMs formation. The analysis of water phase was supplemented by surface analysis of corrosion scales using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDX). The results showed the scales on the pipe surface mainly consisted of Cu(2)O, CuO and Cu(OH)(2) or CuCO(3). Designed experiments confirmed that the fast depletion of chlorine in copper pipe was mainly due to effect of Cu(2)O, CuO in corrosion scales on copper pipe. Although copper(II) and copper oxides showed effect on THMs formation, the rapid consumption of chlorine due to copper oxide made THM levels lower than that in glass bottles after 4h. The transformations of CF, DCBM and CDBM to BF were accelerated in the presence of copper(II), cupric oxide and cuprous oxide. The effect of pH on THMs formation was influenced by effect of pH on corrosion of copper pipe. When pH was below 7, THMs levels in copper pipe was higher as compared to glass bottle, but lower when pH was above 7. PMID:17363030

  4. Copper chip technology

    NASA Astrophysics Data System (ADS)

    Edelstein, Daniel C.

    1998-08-01

    Recently, IBM announced the first silicon integrated circuit technology that incorporates copper on-chip wiring. This technology, which combines industry-leading CMOS ULSI devices with 6 levels of hierarchically-scaled Cu metallization, has reached the point of manufacturing, after passing the qualification tests required to prove feasibility, yield, reliability, and manufacturability. The discussion of the change from Al to Cu interconnects for ULSI encompasses a wide variety of issues. This paper attempts to address these by way of example, from the broad range of detailed studies that have been performed in the course of developing these so-called 'copper chips'. Motivational issues are covered by comparative modeling of performance aspects and cost. The technology parameters and features are shown, as well as data relating to the process integration, electrical yield and parametric behavior, early manufacturing data, high-frequency modeling and measurements, nose and clock skew. The viability of this technology is indicated by results from reliability stressing, as well as the first successful demonstrations of fully functional SRAM, DRAM, and microprocessor chips with Cu wiring. The advantages of integrated Cu wiring may be applied even more broadly in the future. An example shown here is the achievement of very high-quality integrated inductors; these may help prospects for complete integration of RF and wireless communications chips onto silicon.

  5. Synthesis, crystal structure and electronic properties of the new iron selenide Ba9Fe4Se16

    NASA Astrophysics Data System (ADS)

    Berthebaud, David; Preethi Meher, K. R. S.; Pelloquin, Denis; Maignan, Antoine

    2014-03-01

    The new ternary selenide Ba9Fe4Se16 has been synthesized from the reaction of appropriate amounts of elements at high temperature in a silica sealed tube. The compound crystallizes in the tetragonal space group I41/a with a=10.0068(3) Å and c=35.6415(9) Å, Z=4. It is an isostructural compound to the sulfide ?-Ba9Fe4S15, which is a high temperature polymorph of ?-Ba9Fe4Se15 that belongs to the indefinitely adaptive phases series Ba3Fe1+xS5, 0?x?1. X-ray powder diffraction and TEM analyses of the synthesized compound were used to determine the phase composition and the structure. The crystal structure can be viewed as overlapping sections along the c axis. Those sections are formed by the coordination polyhedra around barium atoms which can be described as trigonal prisms and bidisphenoids. Within the sections formed by barium polyhedra, isolated pairs of edge sharing FeSe4 tetrahedra are found. Magnetic measurements performed on Ba9Fe4Se16 indicate an antiferromagnetic behavior with Néel temperature of ~13 K. Possible influence of air exposure on the magnetic properties is also discussed here. The electric measurements show an insulating behavior below 160 K and the dielectric permittivity and loss tangent at the lowest frequency measured reveal a change of slope very close to TN. However no magneto dielectric effect was evidenced for magnetic fields of up to 3 T. Activation energy, EA=0.18 eV, was extracted from the AC conductivity plot in the temperature range of 160-300 K.

  6. Fabrication and material characterization of copper and copper–CNT micropillars

    NASA Astrophysics Data System (ADS)

    Ghanbari, S.; Darabi, J.

    2015-07-01

    In this work, copper micropillars and copper–carbon nanotube (CNT) composite micropillars were fabricated by incorporating an electrodeposition technique with a xurography process. In order to disperse carbon nanotubes in copper–CNT micropillars, various amounts of CNTs were added to the electroplating bath. Surface morphology and phase characterization of copper micropillars and copper–CNT composite micropillars were analyzed by optical microscopy and x-ray diffraction. In addition, the corrosion resistance (Rp) of a bare copper substrate, copper micropillars, and optimum copper–CNT micropillars were studied by electrochemical impedance spectroscopy (EIS) technique in a 3.5 wt.% sodium chloride. Experimental results yielded a corrosion resistance of 200 ? cm2 for the bare copper substrate, 400 ? cm2 for copper micropillars, and 2550 ? cm2 for copper–CNT micropillars, indicating a significantly higher corrosion resistance for copper–CNT micropillars due to a lower chemical reactivity and refinement of crystal structure of copper in micropillars.

  7. Performance of Copper Naphthenate in Fence Posts

    Microsoft Academic Search

    Mike H. Freeman

    This paper reviews the efficacy and field trials of copper naphthenate in various wood species. Included in this discussion are chemical and physical characteristics of copper naphthenate preservative systems, the effect on wood treated with copper naphthenate or copper naphthenate wood preservative systems, and a review of the long-term efficacy trials, in various species of wooden fence posts. Included in

  8. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 3 2014-10-01 2014-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  9. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 3 2010-10-01 2010-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  10. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 3 2011-10-01 2011-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  11. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 3 2013-10-01 2013-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  12. 49 CFR 192.279 - Copper pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 3 2012-10-01 2012-10-01 false Copper pipe. 192.279 Section 192.279 Transportation...of Materials Other Than by Welding § 192.279 Copper pipe. Copper pipe may not be threaded except that copper...

  13. Nano copper conductive ink for RFID application

    Microsoft Academic Search

    Jian Li; Bing An; Jian Qin; Yiping Wu

    2011-01-01

    A novel nano copper conductive ink, composed of anti-oxidation nano copper particles and chemical additives, had been successfully developed and employed for RFID application. A pattern of UHF RFID antenna was chosen to print on polyimide (PI) film by ink-jet printing, and then cured by UV light to form the copper wire. The adhesion of the nano copper ink film

  14. Development of copper wire bonding application technology

    Microsoft Academic Search

    KENJI TOYOZAWA; KAZUYA FUJITA; SYOZO MINAMIDE; TAKAMICHI MAEDA

    1990-01-01

    The continuous forming of oxide-free, stable, spherical copper balls which has been realized by blowing a reducing gas over the copper wire during copper ball formation (sparkling) is described. The prevention of chip damage resulting from hard copper wire, including underpad cracking and silicon cratering, by the double-load wire bonding technology is discussed; this technology can minimize chip damage from

  15. The SLC31 (Ctr) copper transporter family

    Microsoft Academic Search

    Michael J. Petris

    2004-01-01

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

  16. Majorana Electroformed Copper Mechanical Analysis

    SciTech Connect

    Overman, Nicole R.; Overman, Cory T.; Kafentzis, Tyler A.; Edwards, Danny J.; Hoppe, Eric W.

    2012-04-30

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay. The DEMONSTRATOR will utilize ultra high purity electroformed copper for a variety of detector components and shielding. A preliminary mechanical evaluation was performed on the Majorana prototype electroformed copper material. Several samples were removed from a variety of positions on the mandrel. Tensile testing, optical metallography, scanning electron microscopy, and hardness testing were conducted to evaluate mechanical response. Analyses carried out on the Majorana prototype copper to this point show consistent mechanical response from a variety of test locations. Evaluation shows the copper meets or exceeds the design specifications.

  17. Crystal Spectrum of Copper Biguanides

    Microsoft Academic Search

    Animesh Chakravorty; Sadhan Basu

    1960-01-01

    IN a previous communication1 it was shown that the absorption spectrum of a microscopic crystal of copper-ethylene- diamine-bis(acetylacetone) consists of three bands as predicted by the ligand field theory. Copper biguanides form transparent reddish crystals2, very convenient for measurement in our experimental arrangement. In Fig. 1 are given the spectrophotometric optical density (O.D.) vs. wave-length (lambda) curves for a thin

  18. NID Copper Sample Analysis

    SciTech Connect

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  19. Process Of Bonding Copper And Tungsten

    DOEpatents

    Slattery, Kevin T. (St. Charles, MO); Driemeyer, Daniel E. (Manchester, MO); Davis, John W. (Ballwin, MO)

    2000-07-18

    Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by sintering a stack of individual copper and tungsten powder blend layers having progressively higher copper content/tungsten content, by volume, ratio values in successive powder blend layers in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

  20. Ris0-R-991(EN) Fatigue Performance of Copper and

    E-print Network

    Ris0-R-991(EN) inn DK9700117 Fatigue Performance of Copper and Copper alloys before and after ARE MISSING IN THE ORIGINAL DOCUMENT #12;Fatigue Performance of Copper and Copper alloys before and after performance of pure copper of the oxygen free, high conductivity (OFHC) grade and two copper alloys (Cu

  1. Parenteral methods of supplementation with copper and selenium

    Microsoft Academic Search

    WM Allen; CB Mallinson

    1984-01-01

    Parenteral treatments can provide a rapid successful method of supplementing ruminants with copper and selenium, and avoid the possible interactions between an oral supplement and other dietary constituents. The copper preparations studied contained copper complexed with calcium edetate (EDTA) or copper methionate , copper oxide or copper oxyquinoline sulphonate. The recommended doses of these commercial preparations contain different amounts of

  2. Copper and Anesthesia: Clinical Relevance and Management of Copper Related Disorders

    PubMed Central

    Langley, Adrian; Dameron, Charles T.

    2013-01-01

    Recent research has implicated abnormal copper homeostasis in the underlying pathophysiology of several clinically important disorders, some of which may be encountered by the anesthetist in daily clinical practice. The purpose of this narrative review is to summarize the physiology and pharmacology of copper, the clinical implications of abnormal copper metabolism, and the subsequent influence of altered copper homeostasis on anesthetic management. PMID:23762044

  3. Exploration Into Copper Catalyzed and Copper-less Click Reactions with Re(CO)3 Complexes

    E-print Network

    Collins, Gary S.

    Exploration Into Copper Catalyzed and Copper-less Click Reactions with Re(CO)3 Complexes Nicholas that combines a alkyne and an oxime to generate a isoxazole cycloaddtion product. Compared to the copper and then proceeding with the typical copper(I) catalyzed "click" reaction procedure, while the other approach involves

  4. Copper-mediated LDL oxidation by homocysteine and related compounds depends largely on copper ligation

    E-print Network

    Williamson, Mike P.

    Copper-mediated LDL oxidation by homocysteine and related compounds depends largely on copper of copper-mediated LDL oxidation (initiation, conjugated diene formation and aldehyde formation), whereas at high concentration, it acts as an antioxidant. The affinity for copper of homocysteine and related

  5. Nanoscale Growth Twins in Sputtered Copper Films 

    E-print Network

    Anderoglu, Osman

    2011-08-08

    rolling, thick polycrystalline nanotwinned copper foils are sputtered on SiO2 and then peeled off the substrate. Despite the high strength, room temperature rolling experiments show that nanotwinned copper films exhibit stable plastic flow with no shear...

  6. Impact of copper deficiency in humans.

    PubMed

    Prohaska, Joseph R

    2014-05-01

    Humans consume about 1 mg of copper daily, an amount thought adequate for most needs. Genetic, environmental, or physiological alterations can impose a higher copper set point, increasing risk for copper-limited pathophysiology. Humans express about a dozen proteins that require copper for function (cuproenzymes). Limitation in the activity of cuproenzymes can explain the pleiotropic effect of copper deficiency. However, for most of the salient features of human copper deficiency, the precise molecular mechanisms are unknown. This is true for the two most common clinical features, hypochromic anemia and adult onset peripheral neuropathy/ataxia, a condition described frequently in the last decade due to multiple etiologies. The challenge for future scientists will be to identify the mechanisms underlying the pathophysiology of copper deficiency so appropriate screening and treatment can occur. The need for a strong copper biomarker to aid in this screening is critical. PMID:24517364

  7. Molecular mediators governing iron-copper interactions.

    PubMed

    Gulec, Sukru; Collins, James F

    2014-01-01

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

  8. Reliability of copper interconnects in integrated circuits

    E-print Network

    Choi, Zung-Sun

    2007-01-01

    As dimensions shrink and current densities increase, the reliability of metal interconnects becomes a serious concern. In copper interconnects, the dominant diffusion path is along the interface between the copper and the ...

  9. Copper tolerance and virulence in bacteria.

    PubMed

    Ladomersky, Erik; Petris, Michael J

    2015-06-10

    Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(i) and Cu(ii). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

  10. Copper toxicosis of the Bedlington terrier.

    PubMed

    Sternlieb, I

    1981-01-01

    Inherited copper toxicosis of Bedlington terriers provides a valuable animal model for studying mechanisms of hepatic copper accumulation and toxicity. D-penicillamine may be indicated for preventing and treating this potentially serious disorder. PMID:6939891

  11. Determination of copper in clarified apple juices.

    PubMed

    Zeiner, Michaela; Juranovi? Cindri?, Iva; Kröppl, Michaela; Stingeder, Gerhard

    2010-03-24

    Inorganic copper compounds are not considered as synthetic fertilizers for apple trees as they are traditional fertilizers. Thus, they are used in organic farming for soil or foliar applications. The European Union is for health reasons interested in reducing copper in apple orchards. Because the fertilizer application rate affects the nutrition of apples, the applied copper might also be reflected in the copper concentration of apple juices. Thus, the determination of copper is of concern for investigating the application of copper-containing fertilizers. Samples of clarified apple juice commercially available in the European market were analyzed for their copper content. Prior to quantification by inductively coupled plasma-optical emission spectrometry, the juices were processed by a microwave-assisted digestion system using HNO(3). All samples were also measured directly after dilution with HNO(3). The copper concentrations measured using both methods were all below the limit of detection (17 microg/L). PMID:20158210

  12. Strength of welded copper joints

    SciTech Connect

    Kuzyukova, A.N.; Fedorenko, M.I.; Kovalenko, N.I.; Zelik, E.I.

    1983-07-01

    A coefficient of the strength of welded joints in structures of copper and its alloys made by manual arc welding are known. At the Severedonetsk Branch of the Institute of Chemical Engineering the strength coefficients were determined for welded joints made of MZR (phosphorous-deoxydized) copper produced by manual argonarc welding. Optimum welding regimes were selected, and specimens of strips tested for tensile strength. Metallographic investigations showed significant grain growth in the zone of thermal influence. The results of mechanical tests are given. The results are verified by the fabrication of nine models. All the models ruptured in the zone of thermal influence, confirming results that the zone of thermal influence was the weak point in the welded joints in copper.

  13. Copper Post-CMP Cleaning

    NASA Astrophysics Data System (ADS)

    Starosvetsky, D.; Ein-Eli, Y.

    Copper on-chip interconnects Damascene technology utilizes chemical mechanical polishing (CMP) in order to remove copper overburden after its electro deposition and achieve global planarization of patterned surface. CMP is a simultaneous action of mechanical overburden metal removal and its electrochemical dissolution. It is performed with the movement of a polisher pad in acidic or alkaline aqueous CMP electrolytes (slurry) containing dispersive abrasive particles (Al2O3 or SiO2), pH buffer, certain electrolyte salts to control ionic strength, oxidants, and corrosion inhibitors. Mechanical and chemical interactions with a patterned wafer surface introduce different defects and contaminations in interlayer dielectric (ILD) surfaces and copper layers. These can either be mechanical (physical) or chemical-based defects and contaminants [1-6].

  14. Copper content in foods of Java Island and estimation of daily copper intake

    SciTech Connect

    Rivai, I.F.; Suzuki, S.; Koyama, H.; Hyodo, K.; Djuangsih, N.; Soemarwoto, O.

    1988-07-01

    The purpose of this study was first to determine copper content in soil, foodstuff and feces of villagers, and estimate the daily copper intake of the villagers and a guest. The data obtained may help clarify the relationships of copper content in the soil-plant (food)-daily intake-feces in Indonesia. Secondly, the percentage of copper contribution of food groups was calculated to determine the influence of the food patterns of villagers and a guest on daily copper intake. Finally, evaluation was made of daily copper intake of villagers in terms of estimated daily copper requirement by WHO.

  15. New inhibitors for copper corrosion

    Microsoft Academic Search

    E. Szöcs; A. Shaban; E. Kálmán

    2001-01-01

    The study of the effectiveness of several potential copper corrosion inhibitors in acidic media was studied. The investigated thiazole derivative functional groups contain heterocyclic atoms such as nitrogen, sulfur, and oxygen. Thiazole derivatives, 5-benzyli- dene-2,4-dioxotetrahydro-1,3-thiazole (BDT) 5-(4'-isopropylbenzylidene)-2,4-dioxote- trahydro-1,3-thiazole (IPBDT), 5-(3'-thenylidene)-2,4-dioxotetrahydro-1,3-thiazole (TDT), and 5-(3',4'-dimetoxybenzylidene)-2,4-dioxotetrahydro-1,3-thiazole (MBDT) were tested for copper corrosion inhibition properties. The electrolyte solution was 0.1 M Na2SO4. In situ

  16. Copper complexation and toxicity to freshwater zooplankton

    Microsoft Academic Search

    U. Borgmann; K. M. Ralph

    1984-01-01

    The effect of copper on the growth rate of cyclopoid copepods and survival of rotifers was determined in natural water with and without addition of the complexing agent Tris. Free copper concentrations were estimated, both by cupric ion electrode and from the bioassay data, making use of the known complexing ability of Tris and the increase in total copper tolerated

  17. THE EVOLUTION OF SYNTHETICALLY PRECIPITATED COPPER SOLIDS

    EPA Science Inventory

    The objective of this study was to explore the effect of water quality, particularly chloride and sulfate, on copper mineral formation. Copper-sulfate and chloride compounds are often found on the surface of copper pipes in drinking water distribution systems. When attempting to ...

  18. Copper Sequestration Using Local Waste Products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dairies utilize copper sulfate foot baths to control hoof infections. Typical solutions are 5 or 10% copper sulfate (pH ~6), equal to 12,500 or 25,000 parts per million copper, respectively. When spent, hoof bath solutions are usually disposed of in waste lagoons and subsequently utilized for irri...

  19. 21 CFR 524.463 - Copper naphthenate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Copper naphthenate. 524.463 Section...FORM NEW ANIMAL DRUGS § 524.463 Copper naphthenate. (a) Amount. The drug is a 37.5 percent solution of copper naphthenate. (b) Sponsors....

  20. 21 CFR 524.463 - Copper naphthenate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Copper naphthenate. 524.463 Section...FORM NEW ANIMAL DRUGS § 524.463 Copper naphthenate. (a) Amount . The drug is a 37.5 percent solution of copper naphthenate. (b) Sponsors....

  1. Copper complexation in the Northeast Pacific

    Microsoft Academic Search

    KENNETH H. COALE; KENNETH W. BRULAND

    1988-01-01

    Copper titrations were conducted at sea with differential pulse anodic stripping voltammetry to examine the degree to which copper was associated with organic ligands. Greater than 99.7% of the total dissolved copper in surface waters of the central Northeast Pacific shallower than 200 m was estimated to be associated with strong organic complexes. Below 200 m, increasing proportions of inorganic

  2. 21 CFR 73.1647 - Copper powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Copper powder. 73.1647 Section 73.1647...FROM CERTIFICATION Drugs § 73.1647 Copper powder. (a) Identity. (1) The color additive copper powder is a very fine free-flowing...

  3. 21 CFR 184.1261 - Copper sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Drugs 3 2010-04-01 2009-04-01 true Copper sulfate. 184.1261 Section 184.1261 Food...Specific Substances Affirmed as GRAS § 184.1261 Copper sulfate. (a) Copper sulfate (cupric sulfate, CuSO4 ·5H2...

  4. 21 CFR 73.1647 - Copper powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Copper powder. 73.1647 Section 73.1647...FROM CERTIFICATION Drugs § 73.1647 Copper powder. (a) Identity. (1) The color additive copper powder is a very fine free-flowing...

  5. 21 CFR 73.1647 - Copper powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Copper powder. 73.1647 Section 73.1647...FROM CERTIFICATION Drugs § 73.1647 Copper powder. (a) Identity. (1) The color additive copper powder is a very fine free-flowing...

  6. 21 CFR 524.463 - Copper naphthenate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Copper naphthenate. 524.463 Section...FORM NEW ANIMAL DRUGS § 524.463 Copper naphthenate. (a) Amount . The drug is a 37.5 percent solution of copper naphthenate. (b) Sponsors....

  7. 21 CFR 524.463 - Copper naphthenate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Copper naphthenate. 524.463 Section...FORM NEW ANIMAL DRUGS § 524.463 Copper naphthenate. (a) Amount . The drug is a 37.5 percent solution of copper naphthenate. (b) Sponsors....

  8. 21 CFR 524.463 - Copper naphthenate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Copper naphthenate. 524.463 Section...FORM NEW ANIMAL DRUGS § 524.463 Copper naphthenate. (a) Amount . The drug is a 37.5 percent solution of copper naphthenate. (b) Sponsors....

  9. 21 CFR 73.1647 - Copper powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Copper powder. 73.1647 Section 73.1647...FROM CERTIFICATION Drugs § 73.1647 Copper powder. (a) Identity. (1) The color additive copper powder is a very fine free-flowing...

  10. 21 CFR 73.1647 - Copper powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Copper powder. 73.1647 Section 73.1647...FROM CERTIFICATION Drugs § 73.1647 Copper powder. (a) Identity. (1) The color additive copper powder is a very fine free-flowing...

  11. Measuring bioavailable copper using anodic stripping voltammetry

    SciTech Connect

    Deaver, E.; Rodgers, J.H. Jr. [Univ. of Mississippi, University, MS (United States). Dept. of Biology

    1996-11-01

    Since speciation can affect bioavailability and toxicity of copper in aquatic systems, accurate predictions of effects of bioavailable forms require detection and/or measurement of these forms. To develop an approach for measurement of bioavailable copper, a copper sulfate solution was used in 10-d aqueous and sediment toxicity tests with Hyalella azteca Saussure. These tests encompassed ranges of pH, alkalinity, hardness, and conductivity. Changes in copper speciation were measured using atomic absorption spectroscopy (AA) for dissolved copper and differential pulse anodic stripping voltammetry (DPASV) for labile copper, and concentrations were evaluated relative to amphipod survival. Ten-day LC50s based on AA-measured aqueous copper concentrations ranged from 42 to 142 {micro}g Cu/L, and LC50s based on DPASV-measured copper concentrations ranged from 17.4 to 24.8 {micro}g Cu/L. In 10-d tests using copper-amended sediments with diverse characteristics and AA-measured copper concentrations spanning an order of magnitude, total copper concentrations were not predictive of sediment toxicity, but H. azteca survival was explained by DPASV measurements that varied by {le}4%. In order to make defensible estimates of the potential risk of metals in sediments or water, it is essential to identify the fraction of total metal that is bioavailable. In these experiments, DPASV was useful for measuring bioavailable copper in aqueous and sediment tests with H. azteca.

  12. Nanometer-scale switches using copper sulfide

    Microsoft Academic Search

    T. Sakamoto; H. Sunamura; H. Kawaura; T. Hasegawa; T. Nakayama; M. Aono

    2003-01-01

    We describe a nanometer-scale switch that uses a copper sulfide film and demonstrate its performance. The switch consists of a copper sulfide film, which is a chalcogenide semiconductor, sandwiched between copper and metal electrodes. Applying a positive or negative voltage to the metal electrode can repeatedly switch its conductance in under 100 mus. Each state can persist without a power

  13. Thermosonic Gold Wire Bonding to Copper Conductors

    Microsoft Academic Search

    VERNON A. PITT; CHRISTOPHER R. S. NEEDES

    1982-01-01

    The use of thick film copper conductors in hybrid microcircuitry requires that wire bonding to their surfaces be demonstrated as a feasible and reliable interconnection technique. Previous work has shown that acceptable and reliable ultrasonic aluminum wire bonds can be made to copper. The conditions necessary to make successful thermosonic gold wire bonds to copper are described. Items covered are

  14. Copper coating specification for the RHIC arcs

    SciTech Connect

    Blaskiewicz, M.

    2010-12-01

    Copper coating specifications for the RHIC arcs are given. Various upgrade scenarios are considered and calculations of resistive wall losses in the arcs are used to constrain the necessary quality and surface thickness of a copper coating. We find that 10 {mu}m of high purity copper will suffice.

  15. Copper toxicity in aquaculture: A practical approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper sulfate is used as a therapeutant for various applications in aquaculture. There is a great deal of information on the toxicity of copper, especially in low-alkalinity waters; however, much of this information is fragmented, and a comprehensive guide of copper toxicity and safe concentration...

  16. Copper sequestration using local waste products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dairies utilize copper sulfate foot baths to control hoof infections. Typical solutions are 5 or 10% copper sulfate (pH ~6), equal to 12,500 or 25,000 parts per million copper, respectively. When spent, hoof bath solutions are usually disposed of in waste lagoons and subsequently utilized for irri...

  17. The Adsorption of Copper on Tungsten

    Microsoft Academic Search

    J. P. Jones

    1965-01-01

    A detailed examination has been made by field emission microscopy, of the behaviour of small amounts of copper evaporated onto a clean tungsten point in ultra high vacuum. With increasing thickness, the behaviour of the copper deposit and its effect on work function, change in a way which leads to classification of three types of copper layer. Small amounts of

  18. Molybdenum-copper and tungsten-copper alloys and method of making

    DOEpatents

    Schmidt, Frederick A. (Ames, IA); Verhoeven, John D. (Ames, IA); Gibson, Edwin D. (Ames, IA)

    1989-05-23

    Molybdenum-copper and tungsten-copper alloys are prepared by a consumable electrode method in which the electrode consists of a copper matrix with embedded strips of refractory molybdenum or tungsten. The electrode is progressively melted at its lower end with a superatmospheric inert gas pressure maintained around the liquifying electrode. The inert gas pressure is sufficiently above the vapor pressure of copper at the liquidus temperature of the alloy being formed to suppress boiling of liquid copper.

  19. Molybdenum-copper and tungsten-copper alloys and method of making

    DOEpatents

    Schmidt, F.A.; Verhoeven, J.D.; Gibson, E.D.

    1989-05-23

    Molybdenum-copper and tungsten-copper alloys are prepared by a consumable electrode method in which the electrode consists of a copper matrix with embedded strips of refractory molybdenum or tungsten. The electrode is progressively melted at its lower end with a superatmospheric inert gas pressure maintained around the liquefying electrode. The inert gas pressure is sufficiently above the vapor pressure of copper at the liquidus temperature of the alloy being formed to suppress boiling of liquid copper. 6 figs.

  20. Copper vs. Copper at the Relativistic Heavy Ion Collider (2005)

    SciTech Connect

    Brookhaven Lab - Fulvia Pilat

    2009-06-09

    To investigate a new form of matter not seen since the Big Bang, scientists are using a new experimental probe: collisions between two beams of copper ions. The use of intermediate size nuclei is expected to result in intermediate energy density - not as

  1. Copper vs. Copper at the Relativistic Heavy Ion Collider (2005)

    ScienceCinema

    Brookhaven Lab - Fulvia Pilat

    2010-01-08

    To investigate a new form of matter not seen since the Big Bang, scientists are using a new experimental probe: collisions between two beams of copper ions. The use of intermediate size nuclei is expected to result in intermediate energy density - not as

  2. Joining of alumina via copper/niobium/copper interlayers

    SciTech Connect

    Marks, Robert A.; Chapman, Daniel R.; Danielson, David T.; Glaeser, Andreas M.

    2000-03-15

    Alumina has been joined at 1150 degrees C and 1400 degrees C using multilayer copper/niobium/copper interlayers. Four-point bend strengths are sensitive to processing temperature, bonding pressure, and furnace environment (ambient oxygen partial pressure). Under optimum conditions, joints with reproducibly high room temperature strengths (approximately equal 240 plus/minus 20 MPa) can be produced; most failures occur within the ceramic. Joints made with sapphire show that during bonding an initially continuous copper film undergoes a morphological instability, resulting in the formation of isolated copper-rich droplets/particles at the sapphire/interlayer interface, and extensive regions of direct bonding between sapphire and niobium. For optimized alumina bonds, bend tests at 800 degrees C-1100 degrees C indicate significant strength is retained; even at the highest test temperature, ceramic failure is observed. Post-bonding anneals at 1000 degrees C in vacuum or in gettered argon were used to assess joint stability and to probe the effect of ambient oxygen partial pressure on joint characteristics. Annealing in vacuum for up to 200 h causes no significant decrease in room temperature bend strength or change in fracture path. With increasing anneal time in a lower oxygen partial pressure environment, the fracture strength decreases only slightly, but the fracture path shifts from the ceramic to the interface.

  3. Metabolic crossroads of iron and copper

    PubMed Central

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

    2013-01-01

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

  4. Copper sulfate: Liquid or crystals?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two separate experiments were conducted to evaluate copper toxicity to channel catfish and free-swimming Ichthyophthirius multifiliis or Ich (the stage of Ich that can be treated); the compounds we used were CuSO4 crystals and a non-chelated liquid CuSO4 product. In 96 hr tests conducted in aquaria...

  5. Status of Copper Sulfate - 2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is brief overview of the Technical Sections completed and being worked on for the New Animal Drug Application (NADA) for copper sulfate. Initial Label Claim (Ich on catfish): 1) Human Food Safety - Complete for all fin fish - February 2004. This includes human intestinal microflora issues,...

  6. Tetraphenylphosphonium copper(I) dicyanamide.

    SciTech Connect

    Schlueter, J. A.; Geiser, U.; Materials Science Division

    2007-01-01

    In the title compound, {l_brace}(C{sub 24}H{sub 20}P)[Cu(C{sub 2}N{sub 3}){sub 2}]{r_brace}{sub n}, the copper(I) dicyanamide anion forms a distorted three-dimensional single diamondoid network. Templating tetraphenylphosphonium cations reside within the cavities of the polymeric anion.

  7. Michigan's Copper Country in Photographs

    NSDL National Science Digital Library

    2008-06-19

    Copper production has gone on around Michigan's Keweenaw Peninsula for over 3,000 years. Native Americans first engaged in the practice these many millennia ago, and by the 1840s, there were mineral rushes going on in the area. Many thousands of people came in search of copper, and by 1985, over 14 billion pounds of copper were produced from the region. This remarkable digital collection crafted by Michigan Technological University brings together many historical photographs that document the district. All told, there are over 3,500 items here, and visitors can search the holdings by keyword or more detailed parameters. Visitors also have the option of creating their own personal web album with items of interest to them. The Subject Browse tab is a good way to delve into the collection, as visitors can look over anything from Accidents to Woody Plants. This collection illuminates the region and the ways in which the copper industry transformed this rural and bucolic environment.

  8. CopperCore Service Integration

    ERIC Educational Resources Information Center

    Vogten, Hubert; Martens, Harrie; Nadolski, Rob; Tattersall, Colin; van Rosmalen, Peter; Koper, Rob

    2007-01-01

    In an e-learning environment there is a need to integrate various e-learning services like assessment services, collaboration services, learning design services and communication services. In this article we present the design and implementation of a generic integrative service framework, called CopperCore Service Integration (CCSI). We will…

  9. Building a Copper Pipe "Xylophone."

    ERIC Educational Resources Information Center

    Lapp, David R.

    2003-01-01

    Explains how to use the equation for frequency of vibration of a transversely oscillating bar or pipe with both ends free to vibrate to build a simple and inexpensive xylophone from a 3-meter section of copper pipe. The instrument produces a full major scale and can be used to investigate various musical intervals. (Author/NB)

  10. Adrift on the Copper River

    USGS Multimedia Gallery

    Snow drifts in early May at the mouth of the Copper River.  Just a mile or two away from here, at the same elevation, there was no snow. Shown are Woods Hole (MA) scientists Andrew Schroth (left) and Kevin Kroeger (right)....

  11. Subclinical copper accumulation in llamas.

    PubMed Central

    Weaver, D M; Tyler, J W; Marion, R S; Casteel, S W; Loiacono, C M; Turk, J R

    1999-01-01

    A 9-year-old, intact male llama with mild ataxia and generalized malaise of 1 month's duration was euthanized following clinical evaluation. Excessive liver copper concentrations were found in the llama and also in clinically normal herdmates. This case documents multiple animals with increased hepatic stores from standard diets and mineral supplements. PMID:10367160

  12. Status of copper sulfate - 2007

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A brief overview of the Technical Sections completed and being worked on for the New Animal Drug Application (NADA) for copper sulfate will be presented. Various aspects of these technical sections will be open for discussion. The update will include information and dates for both the initial labe...

  13. Deformation of Large Copper Whiskers

    Microsoft Academic Search

    M. N. Shetty

    1968-01-01

    Copper whiskers of [100], [110] and [111] orientation in the diameter (d) range of 30-400 microns are tested in tension. The deformation characteristics of these whiskers are found to be between fine whisker (d<30 microns) and bulk single crystal behaviour. Even though there is no conspicuous yield drop, the maximum flow stress reached in some orientations is comparable to the

  14. Status of copper sulfate - 2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is brief overview of the Technical Sections completed and being worked on for the New Animal Drug Application (NADA) for copper sulfate. Initial Label Claim (Ich on catfish): 1) Human Food Safety - Complete for all fin fish – February 2004. This includes human intestinal microflora issues,...

  15. XIAP: CELL DEATH REGULATION MEETS COPPER HOMEOSTASIS

    PubMed Central

    Mufti, Arjmand R.; Burstein, Ezra; Duckett, Colin S.

    2007-01-01

    SUMMARY X-linked inhibitor of apoptosis (XIAP), traditionally known as an anti-apoptotic protein, has recently been shown to be involved in copper homeostasis. XIAP promotes the ubiquitination and degradation of COMMD1, a protein that promotes the efflux of copper from the cell. Through its effects on COMMD1, XIAP can regulate copper export from the cell and potentially represents an additional intracellular sensor for copper levels. XIAP binds copper directly and undergoes a substantial conformational change in the copper bound state. This in turn destabilizes XIAP, resulting in lowered steady-state levels of the protein. Furthermore, copper-bound XIAP is unable to inhibit caspases and cells that express this form of the protein exhibit increased rates of cell death in response to apoptotic stimuli. These events take place in the setting of excess intracellular copper accumulation as seen in copper toxicosis disorders such as Wilson's disease and establish a new relationship between copper levels and the regulation of cell death via XIAP. These findings raise important questions about the role of XIAP in the development of copper toxicosis disorders and may point to XIAP as a potential therapeutic target in these disease states. PMID:17382285

  16. Process Of Bonding Copper And Tungsten

    DOEpatents

    Slattery, Kevin T. (St. Charles, MO); Driemeyer, Daniel E. (Manchester, MO)

    1999-11-23

    Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by thermal plasma spraying mixtures of copper powder and tungsten powder in a varied blending ratio such that the blending ratio of the copper powder and the tungsten powder that is fed to a plasma torch is intermittently adjusted to provide progressively higher copper content/tungsten content, by volume, ratio values in the interlayer in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

  17. Catastrophic Oxidation of Copper: A Brief Review

    NASA Astrophysics Data System (ADS)

    Belousov, V. V.; Klimashin, A. A.

    2012-10-01

    A brief review of the current understanding of copper accelerated oxidation in the presence of low-melting oxides (Bi2O3, MoO3, and V2O5) is given. Special attention is paid to the kinetics, thermodynamics, and mechanisms of accelerated oxidation of copper. The mechanisms of two stages (fast and superfast) of the copper accelerated oxidation are considered. It is shown that the fast oxidation of copper occurs by a diffusion mechanism. Oxygen diffusion along the liquid channels in the oxide scale is the rate-limiting step in the overall mechanism. The superfast oxidation of copper occurs by a fluxing mechanism. Realization of the particular mechanism depends on the mass ratio of low-melting oxide to the metal. The mass ratios of low-melting oxide to the metal and the oxygen partial pressures for superfast oxidation of copper are established. A model of the fast oxidation of copper is discussed.

  18. Study of layer disorder and microstructural parameters of molybdenumtungsten mixed sulpho-selenide Mo 0.5 W 0.5 S x Se 2- x (0 ? x ? 2) by X-ray line profile analysis

    Microsoft Academic Search

    D. Palit; S. K. Srivastava; M. C. Chakravorti; B. K. Samantaray

    1996-01-01

    The sulphides and selenides of Mo and Ware layered compounds that possess a hexagonal strueture. The electronic structure of these layered transition metal dichalcogenide compounds, e.g. MoS2, WS2, MoSe2, WSe2, etc. [1-6], is of fundamental interest primarily because of the unusual crystal structure of these compounds. Within a layer the bonds are strong; while between adjacent layers, they are weak.

  19. Identification of copper-copper and copper-hydrogen complexes in silicon

    SciTech Connect

    Yarykin, N. A., E-mail: NAY@iptm.ru [Russian Academy of Sciences, Institute of Microelectronics Technology (Russian Federation); Weber, J. [Technische Universitaet Dresden (Germany)

    2013-02-15

    The centers formed in silicon as a result of interaction between the substitutional copper impurity (Cu{sub s}) and interstitial copper (Cu{sub i}) or hydrogen (H) atoms, which are mobile at room temperature, are investigated in this study using the deep-level transient spectroscopy (DLTS) technique. It is shown that a well-known photoluminescence center, which includes four copper atoms, is formed from Cu{sub s} via the subsequent addition of Cu{sub i}. Both intermediate complexes (Cu{sub s}-Cu{sub i} and Cu{sub s}-2Cu{sub i}) are identified by their deep levels in the lower half of the band gap. It is found that Cu{sub s} atoms form complexes with one, two, and three hydrogen atoms, with Cu{sub s}-H and Cu{sub s}-2H being electrically active. It is noted that the addition of either hydrogen or copper has a similar effect on the deep-level structure of Cu{sub s}.

  20. Bioavailability of copper from tribasic copper chloride and copper sulfate in growing cattle

    Microsoft Academic Search

    J. W Spears; E. B Kegley; L. A Mullis

    2004-01-01

    Two experiments were conducted to determine the bioavailability of copper (Cu) from tribasic Cu chloride (Cu2(OH)3Cl) relative to Cu sulfate in growing steers. Experiment 1 compared tribasic Cu chloride to sulfate in terms of ability to maintain Cu status when supplemented to steers fed diets high in the Cu antagonists, molybdenum (Mo) and sulfur (S). Sixty Angus and Angus ×

  1. Accumulation and hyperaccumulation of copper in plants

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    Copper is natural component of our environment. Flow of copper(II) ions in the environment depends on solubility of compounds containing this metal. Mobile ion coming from soil and rocks due to volcanic activity, rains and others are then distributed to water. Bio-availability of copper is substantially lower than its concentration in the aquatic environment. Copper present in the water reacts with other compounds and creates a complex, not available for organisms. The availability of copper varies depending on the environment, but moving around within the range from 5 to 25 % of total copper. Thus copper is stored in the sediments and the rest is transported to the seas and oceans. It is common knowledge that copper is essential element for most living organisms. For this reason this element is actively accumulated in the tissues. The total quantity of copper in soil ranges from 2 to 250 mg / kg, the average concentration is 30 mg / kg. Certain activities related to agriculture (the use of fungicides), possibly with the metallurgical industry and mining, tend to increase the total quantity of copper in the soil. This amount of copper in the soil is a problem particularly for agricultural production of food. The lack of copper causes a decrease in revenue and reduction in quality of production. In Europe, shows the low level of copper in total 18 million hectares of farmland. To remedy this adverse situation is the increasing use of copper fertilizers in agricultural soils. It is known that copper compounds are used in plant protection against various illnesses and pests. Mining of minerals is for the development of human society a key economic activity. An important site where the copper is mined in the Slovakia is nearby Smolníka. Due to long time mining in his area (more than 700 years) there are places with extremely high concentrations of various metals including copper. Besides copper, there are also detected iron, zinc and arsenic. Various plant species have adapted on such stress. The aim of this study is to investigate the behaviour of copper in plants and to assess its potential effect on the surrounding environment. To detect copper in biological samples electrochemical methods were employed particularly differential pulse voltammetry (DPV). Copper gave signals at 0.02 V measured by DPV. The obtained calibration dependence was linear (R2 = 0.995). Further, this method was utilized for determination of copper in real soil samples obtained from previously mentioned heavy-metal-polluted mining area. The content varied within range from tens to hundreds of mg of copper per kg of the soil. Moreover, we focused on investigation of copper influence on seedlings of Norway spruce. The seedlings were treated with copper (0, 0.1, 10 and 100 mM) for four weeks. We observed anatomical-morphological changes and other biochemical parameters in plants. We determined that seedlings synthesized more than 48 % protective thiols (glutathione and phytochelatins) compared to control ones. We investigated copper distribution in plant tissues by diphenylcarbazide staining. We found out that copper is highly accumulated in parenchymal stalk cells. In needles, change in auto-fluorescence of parenchymal cells of mesoderm similarly to endodermis cells. Besides, we analyzed samples of plants from the polluted area (spruce, pin, birch). The data obtained well correlated with previously mentioned. Acknowledgement The work on this experiment was supported by grant: INCHEMBIOL MSM0021622412.

  2. Dietary copper influences reproduction in cats.

    PubMed

    Fascetti, A J; Rogers, Q R; Morris, J G

    2000-05-01

    The objective of this study was to determine the copper requirement of female cats (queens) for gestation. Cuproenzyme activities were evaluated to identify a noninvasive indicator of copper status. This study used a depletion-repletion model. Specific pathogen-free queens (n = 28) were adapted to a purified diet; after consuming a copper-depletion diet (0.8 mg Cu/kg diet) for 4 mo, they were randomly allocated to three dietary treatment groups receiving copper sulfate at 4.0, 5.8 or 10.8 mg Cu/kg diet. Four queens underwent liver biopsies at two time points during the study. Plasma samples were analyzed for copper concentrations, extracellular superoxide dismutase, ceruloplasmin and diamine oxidase activities. Only liver copper concentrations were responsive to dietary copper intake. The dietary concentration of copper had a significant effect on the time taken for queens to conceive (P = 0.04). There was a negative linear relationship between dietary copper (x = Cu mg/kg diet) and the mean time (y = days) for queens to conceive (y = 43.38-2.87x; R(2) = 0.97). The current NRC recommendation of 5 mg/kg diet copper for cats appears marginal for optimal reproduction. PMID:10801931

  3. Copper sensitivity of Oregon coastal phytoplankton

    SciTech Connect

    Riedel, G.F.

    1983-01-01

    The copper sensitivity of natural populations of Oregon coastal phytoplankton was studied using both additions of ionic copper and Cu-TRIS free ion activity buffers in coastal seawater. Phytoplankton growth rate, taxonomic composition and copper content were examined in treatment additions. The growth rate results suggested that the deficiency of another trace metal increased the apparent toxicity of copper to phytoplankton, especially in TRIS-free ion activity buffered seawater. Laboratory experiments with isolated coastal phytoplankton species indicated that manganese deficiency exacerbated copper toxicity, and that manganese deficiency was induced in TRIS buffered seawater by a TRIS-catalyzed oxidation of Mn. When manganese additions to natural populations were employed inconjunction with ionic copper additions and TRIS-free ion regulated seawater, they showed that ambient manganese concentrations were low enough to shift the onset of copper toxicity to lower copper concentrations. The results suggest that while acute toxicity to phytoplankton by ambient concentrations of copper is unlikely, the interactions of copper and other metals, especially manganese, may influence natural coastal phytoplankton populations in more subtle ways, such as taxonomic composition.

  4. Investigations of copper speciation and bioavailability

    SciTech Connect

    Deaver, E.; Rodgers, J.H. Jr. [Univ. of Mississippi, University, MS (United States)

    1995-12-31

    Speciation, or form in which copper occurs, can effect the bioavailability and therefore, the toxicity of that element. One needs to determine the bioavailable forms of copper in sediment/water effects on organisms. In both water and sediment experiments, physical/chemical factors influencing copper speciation were evaluated and related to organism responses. Ten day aqueous experiments encompassing a range of pH (6.5--8.1), alkalinity (10--70 mg/L as CaCO{sub 3}), hardness (10--70 mg/L as CaCO{sub 3}) and conductivity (30--300 umhos/cm) were conducted using Hyalella azteca. Amphipod survival was evaluated relative to changes in water characteristics and concomitant changes in copper speciation as measured using atomic adsorption spectroscopy (AA) for acid extractable copper, and differential pulse anodic stripping voltammetry (DPASV) for labile copper. Ten day LC50s based on AA measured copper concentrations ranged from 42 to 142 ug/L Cu, and LC50s based on DPASV measured copper concentrations ranged from 17.4--24.8 ug/L Cu. Ten day sediment experiments encompassing a range of sediment pH, organic carbon content, acid volatile sulfides and redox concentrations were also conducted using H. azteca. Overlying water (AA and DPASV) and sediment copper concentrations (AA) were measured and evaluated relative to organism survival. Ten day sediment test LC50s based on DPASV measured copper concentrations in overlying water were 18.5 and 18 ug/L Cu for experiments in sandy and silty sediments, respectively. Organism survival, used as a measure of bioavailable copper, was evaluated in relation to measured copper species concentrations and used to develop guidelines for predicting copper toxicity in freshwater systems.

  5. BotEC: Percentage of Copper in Ore

    NSDL National Science Digital Library

    Barb Tewksbury

    Question Suppose that you are building a new house. It will take about 90 kg (198 pounds) of copper to do the electrical wiring. In order to get the copper in the first place, someone needs to mine solid rock that contains copper, extract the copper minerals, throw away the waste rock, and smelt the copper minerals to produce copper metal. Rocks mined for copper typically contain only very small percentages of copperâabout 0.7% in the case of most of the big porphyry copper deposits of the world. How much rock would someone have to mine in order to extract enough copper to wire your new house?

  6. Copper-induced production of copper-binding supernatant proteins by the marine bacterium Vibrio alginolyticus.

    PubMed Central

    Harwood-Sears, V; Gordon, A S

    1990-01-01

    Growth of the marine bacterium Vibrio alginolyticus is temporarily inhibited by micromolar levels of copper. During the copper-induced lag phase, supernatant compounds which complex and detoxify copper are produced. In this study two copper-inducible supernatant proteins having molecular masses of ca. 21 and 19 kilodaltons (CuBP1 and CuBP2) were identified; these proteins were, respectively, 25 and 46 times amplified in supernatants of copper-challenged cultures compared with controls. Experiments in which chloramphenicol was added to cultures indicated that there was de novo synthesis of these proteins in response to copper. When supernatants were separated by gel permeation chromatography, CuBP1 and CuBP2 coeluted with a copper-induced peak in copper-binding activity. CuBP1 and CuBP2 from whole supernatants were concentrated and partially purified by using a copper-charged immobilized metal ion affinity chromatography column, confirming the affinity of these proteins for copper. A comparison of cell pellets and supernatants demonstrated that CuBP1 was more concentrated in supernatants than in cells. Our data are consistent with a model for a novel mechanism of copper detoxification in which excretion of copper-binding protein is induced by copper. Images PMID:2339887

  7. Antimicrobial activity of different copper alloy surfaces against copper resistant and sensitive Salmonella enterica.

    PubMed

    Zhu, Libin; Elguindi, Jutta; Rensing, Christopher; Ravishankar, Sadhana

    2012-05-01

    Copper has shown antibacterial effects against foodborne pathogens. The objective of this study was to evaluate the antibacterial activity of copper surfaces on copper resistant and sensitive strains of Salmonella enterica. Six different copper alloy coupons (60-99.9% copper) were tested along with stainless steel as the control. The coupons were surface inoculated with either S. Enteritidis or one of the 3 copper resistant strains, S. Typhimurium S9, S19 and S20; stored under various incubation conditions at room temperature; and sampled at various times up to 2 h. The results showed that under dry incubation conditions, Salmonella only survived 10-15 min on high copper content alloys. Salmonella on low copper content alloys showed 3-4 log reductions. Under moist incubation conditions, no survivors were detected after 30 min-2 h on high copper content alloys, while the cell counts decreased 2-4 logs on low copper content coupons. Although the copper resistant strains survived better than S. Enteritidis, they were either completely inactivated or survival was decreased. Copper coupons showed better antimicrobial efficacy in the absence of organic compounds. These results clearly show the antibacterial effects of copper and its potential as an alternative to stainless steel for selected food contact surfaces. PMID:22265316

  8. Direct, rapid, facile photochemical method for preparing copper nanoparticles and copper patterns.

    PubMed

    Zhu, Xiaoqun; Wang, Bowen; Shi, Feng; Nie, Jun

    2012-10-01

    We develop a facile method for preparing copper nanoparticles and patterned surfaces with copper stripes by ultraviolet (UV) irradiation of a mixture solution containing a photoinitiator and a copper-amine coordination compound. The copper-amine compound is formed by adding diethanol amine to an ethanol solution of copper chloride. Under UV irradiation, free radicals are generated by photoinitiator decomposition. Meanwhile, the copper-amine coordination compound is rapidly reduced to copper particles because the formation of the copper-amine coordination compound prevents the production of insoluble cuprous chloride. Poly(vinylpyrrolidone) is used as a capping agent to prevent the aggregation of the as-prepared copper nanoparticles. The capping agent increases the dispersion of copper nanoparticles in the ethanol solution and affects their size and morphology. Increasing the concentration of the copper-amine coordination compound to 0.1 M directly forms a patterned surface with copper stripes on the transparent substrate. This patterned surface is formed through the combination of the heterogeneous nucleation of copper nanoparticles and photolithography. We also investigate the mechanism of photoreduction by UV-vis spectroscopy and gas chromatography-mass spectrometry. PMID:22974517

  9. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption

    PubMed Central

    Andreazza, R.; Pieniz, S.; Okeke, B.C.; Camargo, F.A.O

    2011-01-01

    Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29°09?53.92?S and 51°31?39.40?W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30°29?43.48?S and 53?32?37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L?1 in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration. PMID:24031606

  10. “Pulling the plug” on cellular copper: The role of mitochondria in copper export

    PubMed Central

    Leary, Scot C.; Winge, Dennis R.; Cobine, Paul A.

    2014-01-01

    Mitochondria contain two enzymes, Cu, Zn superoxide dismutase (Sod1) and cytochrome c oxidase (CcO), that require copper as a cofactor for their biological activity. The copper used for their metallation originates from a conserved, bioactive pool contained within the mitochondrial matrix, the size of which changes in response to either genetic or pharmacological manipulation of cellular copper status. Its dynamic nature implies molecular mechanisms exist that functionally couple mitochondrial copper handling with other, extramitochondrial copper trafficking pathways. The recent finding that mitochondrial proteins with established roles in CcO assembly can also effect changes in cellular copper levels by modulating copper efflux from the cell supports a mechanistic link between organellar and cellular copper metabolism. However, the proteins and molecular mechanisms that link trafficking of copper to and from the organelle with other cellular copper trafficking pathways are unknown. This review documents our current understanding of copper trafficking to, and within, the mitochondrion for metallation of CcO and Sod1; the pathways by which the two copper centers in CcO are formed; and, the interconnections between mitochondrial function and the regulation of cellular copper homeostasis. PMID:18522804

  11. Comparative efficacy of several potential treatments for copper mobilization in copper-overloaded rats.

    PubMed

    Domingo, J L; Gómez, M; Jones, M M

    2000-05-01

    D-Penicillamine (DPA) is effective in the treatment of Wilson's disease, whereas zinc salts are also used as a therapy for this disorder of copper transport. Recently, it has been shown that the copper chelators 1,4,7,11-tetraazaundecane tetrahydrochloride (TAUD) and tetraethylenepentamine pentahydrochloride (TETREN) could be useful for copper mobilization in rats. Because these agents could be potential clinical alternatives to DPA for patients with Wilson's disease who are intolerant to this drug, we examined whether oral administration of TAUD and TETREN could be effective in mobilizing copper in experimental copper-overloaded rats. The efficacy of a combined administration of zinc and DPA, TAUD, or TETREN was also assessed. Rats were copper loaded with 0.125% copper acetate in water for 12 wk. After this period, DPA, TAUD, and TETREN were administered by gavage at 0.67 mmol/kg/d for 5 d, and zinc was given at 2.5 mg Zn/kg/d. Twelve weeks of copper loading resulted in a 32-fold increase in total hepatic copper. TETREN was the most effective chelator in increasing the urinary excretion of copper. However, it did not reduce significantly the hepatic copper levels. In turn, combined administration of zinc and chelating agents significantly reduced the amount of copper found in the feces. Although TAUD and TETREN showed a similar or higher efficacy to DPA in mobilizing copper, concurrent treatment of chelating agents and zinc salts should be discarded according to the current results. PMID:11051587

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

    SciTech Connect

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

    1992-01-01

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

  13. Copper-induced production of copper-binding supernatant proteins by the marine bacterium Vibrio alginolyticus

    SciTech Connect

    Harwood-Sears, V.; Gordon, A.S. (Old Dominion Univ., Norfolk, VA (USA))

    1990-05-01

    Growth of the marine bacterium Vibrio alginolyticus is temporarily inhibited by micromolar levels of copper. During the copper-induced lag phase, supernatant compounds and detoxify copper are produced. In this study two copper-inducible supernatant proteins having molecular masses of ca. 21 and 19 kilodaltons (CuBP1 and CuPB2) were identified; these proteins were, respectively, 25 and 46 times amplified in supernatants of copper-challenged cultures compared with controls. Experiments in which chloramphenicol was added to cultures indicated that there was de novo synthesis of these proteins in response to copper. When supernatants were separated by gel permeation chromatography, CuBP1 and CuPB2 coeluted with a copper-induced peak in copper-binding activity. CuBP1 and CuBP2 from whole supernatants were concentrated and partially purified by using a copper-charged immobilized metal ion affinity chromatography column, confirming the affinity of these proteins for copper. A comparison of cell pellets and supernatants demonstrated that CuBP1 was more concentrated in supernatants than in cells. Our data are consistent with a model for a novel mechanism of copper detoxification in which excretion of copper-binding protein is induced by copper.

  14. Electrical conductance of bolted copper joints for cryogenic applications

    E-print Network

    Paris-Sud XI, Université de

    Electrical conductance of bolted copper joints for cryogenic applications F. Blondelle · A. Sultan contact resistance measurements at low temperatures on copper-to-copper bolted joints. Our accurate resistances in sim- ple copper-to-copper bolted joints, used in our fast-cooling pulse-tube dilution

  15. Copper complexes with bioactive ligands

    Microsoft Academic Search

    B. Dudová; D. Hudecová; R. Pokorný; M. Mi?ková; M. Palicová; P. Segl'a; M. Melník

    2002-01-01

    Antifungal activity of new copper(II) complexes of 2-methylthionicotinate (2-MeSNic) of the composition Cu(2-MeSNic)2(MeNia)2·4H2O (where MeNia isN-methylnicotinamide), and Cu(2-MeSNic)2(Nia)2·2H2O (where Nia is nicotinamide) and Cu(2-MeSNic)2L2 (where L is isonicotinamide, iNia, or ethyl nicotinate, EtNic) were tested on various strains of filamentous fungi by the\\u000a macrodilution method. Most sensitive against copper(II) adducts with bioactive ligands wereRhizopus oryzae andMicrosporum gypseum (IC50 1.5–2.3 mmol\\/L).

  16. Copper disinfection ban causes storm.

    PubMed

    Lester, Alan

    2013-05-01

    Since 1 February this year, under the EU's Biocidal Products Directive, it has been illegal to sell or use water treatment systems that use elemental copper, a practice employed historically by a significant number of UK healthcare facilities to combat Legionella. Alan Lester, managing director of specialist supplier of 'environmentally-friendly' water treatment systems, Advanced Hydro, says the ban has caused 'a storm of giant proportion,' with advocates of copper ion-based treatment systems arguing that this disinfection method dates back 3,000 years to Egyptian times, making it an 'undoubtedly proven' technology. Here he explains why the ban came into force, considers why the UK's Health and Safety Executive (HSE) is seeking a derogation, looks at the ban's likely impact, and gives a personal viewpoint on the 'pros and cons' of some of the alternative treatment technologies, including a titanium dioxide-based system marketed by Advanced Hydro itself in the UK. PMID:23763088

  17. Fast Sintering of Nanocrystalline Copper

    Microsoft Academic Search

    Alessandro Fais; Matteo Leoni; Paolo Scardi

    2011-01-01

    The behavior of nanocrystalline (nc) copper specimens obtained by high energy ball milling (HEBM) and electromagnetic field-assisted\\u000a sintering under stress and mechanical compression is explored. High yield stress values combined with plastic behavior are\\u000a observed. The basic densification mechanisms involved in the production process and the peculiar action on the dislocation\\u000a network are discussed.

  18. Chronic Copper Poisoning in Sheep.

    E-print Network

    Boughton, I. B. (Ivan Bertrand); Hardy, W. T. (William Tyree)

    1934-01-01

    POISONING IN SHEEP A trouble occurring among sheep on numerous ranches in the Edwards plateau region of Texas characterized clinically by generalized icterus, hemoglobinuria and hematuria, inappetence, and extreme weakness, was found to be chronic copper... liver; enlarged, very dark brown to black kidneys; a swollen, "blackberry jam" spleen; generalized icterus; poorly- collapsed, doughy lungs, and a pale flaccid heart. As a matter of fact the condition is really a cumulative poisoning since...

  19. COPPER VESSEL, MAGIC AND DISEASE

    PubMed Central

    Richter, Franz–Helmut; Thoss, Gabriele

    1986-01-01

    The use of a copper vessel as a magic and a medical aid in South Indian Folkmedicine is described. The authors discuss its relation to the neglected external treatments of Siddha Medicine and the use of cupping glasses in West Germany. With this article they want to rise the interest in a comparative study of the different medical systems and to emphasize the use of the external treatments in Siddha Medicine, which are rarely practiced today. PMID:22557555

  20. Copper: a metal for the ages

    USGS Publications Warehouse

    Doebrich, Jeff

    2009-01-01

    Copper was one of the first metals ever extracted and used by humans, and it has made vital contributions to sustaining and improving society since the dawn of civilization. Copper was first used in coins and ornaments starting about 8000 B.C., and at about 5500 B.C., copper tools helped civilization emerge from the Stone Age. The discovery that copper alloyed with tin produces bronze marked the beginning of the Bronze Age at about 3000 B.C. Copper is easily stretched, molded, and shaped; is resistant to corrosion; and conducts heat and electricity efficiently. As a result, copper was important to early humans and continues to be a material of choice for a variety of domestic, industrial, and high-technology applications today.

  1. MicroRNA-mediated Systemic Down-regulation of Copper Protein Expression in Response to Low Copper

    E-print Network

    MicroRNA-mediated Systemic Down-regulation of Copper Protein Expression in Response to Low Copper 44519, Egypt In plants, copper is an essential micronutrient required for photosynthesis. Two of the most abundant copper proteins, plastocyanin and copper/zinc superoxide dismutase, are found

  2. The Fission Yeast Copper-sensing Transcription Factor Cuf1 Regulates the Copper Transporter Gene Expression through an

    E-print Network

    Labbé, Simon

    The Fission Yeast Copper-sensing Transcription Factor Cuf1 Regulates the Copper Transporter Gene of copper transport is essential for copper homeostasis and growth in yeast. Analysis of regulatory regions in the promoter of the ctr4 copper transporter gene in fission yeast Schizosaccharomyces pombe re- veals

  3. Copper(I) and copper(II) complexes of an ethylene cross-bridged cyclam

    E-print Network

    Hubin, Tim

    Copper(I) and copper(II) complexes of an ethylene cross-bridged cyclam Timothy J. Hubin,a Nathaniel and crystal structures of (4,11-dibenzyl- 1,4,8,11-tetraazabicyclo[6.6.2]hexadecane- 4 N)copper(I) hexa)- copper(II) bis(hexa¯uorophosphate), [Cu(C2H3N)(C26H38- N4)](PF6)2, are described. The CuI ion

  4. The Copper Chaperone Atox1 in Canine Copper Toxicosis in Bedlington Terriers

    Microsoft Academic Search

    Manoj. S. Nanji; Diane. W. Cox

    1999-01-01

    Copper toxicosis, resulting in liver disease, commonly occurs in Bedlington terriers. This recessively inherited disorder, similar in many respects to Wilson disease, is of particular interest because the canine Atp7b gene, homologous to ATP7B defective in Wilson disease, is not responsible for canine copper toxicosis as has been expected. Atox1, a copper chaperone delivering copper to Atp7b, therefore became a

  5. Ultraviolet photoelectron spectroscopy of copper clusters

    Microsoft Academic Search

    C. L. Pettiette; S. H. Yang; M. J. Craycraft; J. Conceicao; R. T. Laaksonen; O. Cheshnovsky; R. E. Smalley

    1988-01-01

    Using a new magnetically focused time-of-flight photoelectron spectrometer, the ultraviolet photoelectron spectra (UPS) of mass-selected negative copper clusters have been measured at photon energy of 4.66 eV for all clusters in the range from 6 through 41 copper atoms. These UPS data provide the first detailed probe of the 4s valence band structure of such medium size negative copper clusters,

  6. Geochemical characteristics of porphyry copper (molybdenum) mineralization

    Microsoft Academic Search

    Bingqiu Zhu; Waisheng Xu

    1985-01-01

    Dealt with in this paper are some geochemical characteristics of porphyry copper mineralization, especially those observed\\u000a in intrusive bodies, wall rocks, alteration zones, ores and pyrites. Ore bearing bodies have been correlated with barren ones\\u000a from such aspects as major and trace elements, copper contents of biotite and pyrite, and distribution pattern of copper.\\u000a In the mineralized rocks, trace elements

  7. Electroless copper metallisation of titanium nitride

    Microsoft Academic Search

    J. C. Patterson; C. Ni Dheasuna; J. Barrett; T. R. Spalding; M. O'Reilly; X. Jiang; G. M. Crean

    1995-01-01

    This paper reports on electroless copper plating as a novel low temperature, selective technique for metallisation of TiN. Various properties of the as-deposited copper were examined. The adhesion of the as-deposited Cu was tested by a quantitative pull test and a force of 1.5–1.7 kg\\/mm2 failed to remove the copper from the TiN surface. It was found that the as-deposited

  8. Copper chloride cathode for a secondary battery

    NASA Technical Reports Server (NTRS)

    Bugga, Ratnakumar V. (inventor); Distefano, Salvador (inventor); Nagasubramanian, Ganesan (inventor); Bankston, Clyde P. (inventor)

    1990-01-01

    Higher energy and power densities are achieved in a secondary battery based on molten sodium and a solid, ceramic separator such as a beta alumina and a molten catholyte such as sodium tetrachloroaluminate and a copper chloride cathode. The higher cell voltage of copper chloride provides higher energy densities and the higher power density results from increased conductivity resulting from formation of copper as discharge proceeds.

  9. InsideIllinoisDec. 19, 2013 Vol. 33, No. 12

    E-print Network

    Lewis, Jennifer

    to a par- ticular structure. They can make a nano- crystal of one material and transform it into another tiny crystals of the material cad- mium selenide to crystals of copper sel- enide. Copper selenide selenide creates nano- crystals with a purity difficult to attain from other methods. The researchers

  10. Cytological detection of copper for the diagnosis of inherited copper toxicosis in Bedlington terriers

    Microsoft Academic Search

    E Teske; BG Brinkhuis; P Bode; TS van den Ingh; J Rothuizen

    1992-01-01

    The reliability of a cytological examination of impression smears of the liver was investigated in 89 Bedlington terriers by using the rubeanic acid staining method for copper and comparing the results with the results of a histological examination. Histological examination revealed copper accumulation in the liver of 24 dogs. The cytological method had a sensitivity of 0.96 for detecting copper

  11. XIAP Is a Copper Binding Protein Deregulated in Wilson's Disease and Other Copper Toxicosis Disorders

    Microsoft Academic Search

    Arjmand R. Mufti; Ezra Burstein; Rebecca A. Csomos; Paul C. F. Graf; John C. Wilkinson; Robert D. Dick; Madhavi Challa; Jae-Kyoung Son; Shawn B. Bratton; Grace L. Su; George J. Brewer; Ursula Jakob; Colin S. Duckett

    2006-01-01

    Summary X-linked inhibitor of apoptosis (XIAP), known primarily for its caspase inhibitory properties, has recently been shown to interact with and regulate the levels of COMMD1, a protein associated with a form of canine copper toxicosis. Here, we describe a role for XIAP in copper metabolism. We find that XIAP levels are greatly reduced by intracellular copper accumulation in Wilson's

  12. High intensity copper atom beam - Preliminary results

    NASA Technical Reports Server (NTRS)

    Kelly, A. J.; Santavicca, D.

    1973-01-01

    The development of a nozzle which gas-dynamically accelerates neutral copper atoms at controlled energy levels and flux rates suitable for the investigation of inelastic copper atom collision processes is reported. Preliminary test data demonstrate that vapor-deposited rhenium nozzles do not degrade in the presence of copper vapor at high temperatures. Operation with high purity helium gas at nozzle stagnation temperatures in the range 2650-2700 K and total stagnation pressures from 1/4 to 2 atm with continuous copper atom flux rates of approximately 10 to the 18th power per second has been maintained, for a total time of 8-1/2 h to date.

  13. [Copper in methane oxidation: a review].

    PubMed

    Su, Yao; Kong, Jiao-Yan; Zhang, Xuan; Xia, Fang-Fang; He, Ruo

    2014-04-01

    Methane bio-oxidation plays an important role in the global methane balance and warming mitigation, while copper has a crucial function in methane bio-oxidation. On one side, copper is known to be a key factor in regulating the expression of the genes encoding the two forms of methane monooxygenases (MMOs) and is the essential metal element of the particulate methane monooxygenase (pMMO). On the other side, the content and fractionation of copper in the environment have great effects on the distribution of methanotrophs and their metabolic capability of methane and non-methane organic compounds, as well as on the copper-specific uptake systems in methanotrophs. Thus, it is meaningful to know the role of copper in methane bio-oxidation for comprehensive understanding of this process and is valuable for guiding the application of methanotrophs in greenhouse gas removal and pollution remediation. In this paper, the roles of copper in methane oxidation were reviewed, including the effect of copper on methanotrophic community structure and activity, the expression and activity of MMOs as well as the copper uptake systems in methanotrophs. The future studies of copper and methane oxidation were also discussed. PMID:25011321

  14. 49 CFR 192.377 - Service lines: Copper.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Service lines: Copper. 192.377 Section 192.377 Transportation...and Service Lines § 192.377 Service lines: Copper. Each copper service line installed within a building must be...

  15. 19 CFR 10.98 - Copper-bearing fluxing material.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Copper-bearing fluxing material. 10.98...Provisions Fluxing Material § 10.98 Copper-bearing fluxing material. ...contain by weight not over 15 percent copper. (b) [Reserved] (c)...

  16. 21 CFR 73.125 - Sodium copper chlorophyllin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Sodium copper chlorophyllin. 73.125 Section...CERTIFICATION Foods § 73.125 Sodium copper chlorophyllin. (a) Identity. (1) The color additive sodium copper chlorophyllin is a green to...

  17. 49 CFR 192.377 - Service lines: Copper.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Service lines: Copper. 192.377 Section 192.377 Transportation...and Service Lines § 192.377 Service lines: Copper. Each copper service line installed within a building must be...

  18. 49 CFR 192.377 - Service lines: Copper.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Service lines: Copper. 192.377 Section 192.377 Transportation...and Service Lines § 192.377 Service lines: Copper. Each copper service line installed within a building must be...

  19. 19 CFR 10.98 - Copper-bearing fluxing material.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Copper-bearing fluxing material. 10.98...Provisions Fluxing Material § 10.98 Copper-bearing fluxing material. ...contain by weight not over 15 percent copper. (b) [Reserved] (c)...

  20. 21 CFR 73.125 - Sodium copper chlorophyllin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Sodium copper chlorophyllin. 73.125 Section...CERTIFICATION Foods § 73.125 Sodium copper chlorophyllin. (a) Identity. (1) The color additive sodium copper chlorophyllin is a green to...

  1. 19 CFR 10.98 - Copper-bearing fluxing material.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Copper-bearing fluxing material. 10.98...Provisions Fluxing Material § 10.98 Copper-bearing fluxing material. ...contain by weight not over 15 percent copper. (b) [Reserved] (c)...

  2. 21 CFR 862.1190 - Copper test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 2012-04-01 false Copper test system. 862.1190 Section 862...Clinical Chemistry Test Systems § 862.1190 Copper test system. (a) Identification. A copper test system is a device intended to...

  3. 21 CFR 73.125 - Sodium copper chlorophyllin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Sodium copper chlorophyllin. 73.125 Section...CERTIFICATION Foods § 73.125 Sodium copper chlorophyllin. (a) Identity. (1) The color additive sodium copper chlorophyllin is a green to...

  4. 19 CFR 10.98 - Copper-bearing fluxing material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Copper-bearing fluxing material. 10.98...Provisions Fluxing Material § 10.98 Copper-bearing fluxing material. ...contain by weight not over 15 percent copper. (b) [Reserved] (c)...

  5. 21 CFR 862.1190 - Copper test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 2013-04-01 false Copper test system. 862.1190 Section 862...Clinical Chemistry Test Systems § 862.1190 Copper test system. (a) Identification. A copper test system is a device intended to...

  6. 21 CFR 73.125 - Sodium copper chlorophyllin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Sodium copper chlorophyllin. 73.125 Section...CERTIFICATION Foods § 73.125 Sodium copper chlorophyllin. (a) Identity. (1) The color additive sodium copper chlorophyllin is a green to...

  7. 21 CFR 862.1190 - Copper test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 2011-04-01 false Copper test system. 862.1190 Section 862...Clinical Chemistry Test Systems § 862.1190 Copper test system. (a) Identification. A copper test system is a device intended to...

  8. 21 CFR 862.1190 - Copper test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 2014-04-01 false Copper test system. 862.1190 Section 862...Clinical Chemistry Test Systems § 862.1190 Copper test system. (a) Identification. A copper test system is a device intended to...

  9. 21 CFR 73.125 - Sodium copper chlorophyllin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Sodium copper chlorophyllin. 73.125 Section...CERTIFICATION Foods § 73.125 Sodium copper chlorophyllin. (a) Identity. (1) The color additive sodium copper chlorophyllin is a green to...

  10. 49 CFR 192.377 - Service lines: Copper.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Service lines: Copper. 192.377 Section 192.377 Transportation...and Service Lines § 192.377 Service lines: Copper. Each copper service line installed within a building must be...

  11. 49 CFR 192.377 - Service lines: Copper.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Service lines: Copper. 192.377 Section 192.377 Transportation...and Service Lines § 192.377 Service lines: Copper. Each copper service line installed within a building must be...

  12. 19 CFR 10.98 - Copper-bearing fluxing material.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Copper-bearing fluxing material. 10.98...Provisions Fluxing Material § 10.98 Copper-bearing fluxing material. ...contain by weight not over 15 percent copper. (b) [Reserved] (c)...

  13. 21 CFR 862.1190 - Copper test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2010-04-01 false Copper test system. 862.1190 Section 862...Clinical Chemistry Test Systems § 862.1190 Copper test system. (a) Identification. A copper test system is a device intended to...

  14. Evaluations of bioavailable copper in amended wetland sediments

    SciTech Connect

    Deaver, E.; Rodgers, J.H. Jr. [Univ. of Mississippi, University, MS (United States)

    1994-12-31

    Copper sulfate was added to the water column of six of twelve wetland mesocosms. In successive 10d experiments using invertebrates Hyalella azteca and Chironomus tentans, sediment toxicity and copper bioavailability were examined in sediments collected monthly from wetlands amended with copper sulfate, untreated wetlands, and control sediments. Evaluations included examinations of temporal changes in toxicity, bioavailability of aqueous and sediment associated copper, and comparison of organism responses to copper. In some cases copper remained acutely toxic over the 6 month study period, however, total copper concentrations in sediment had no relation to bioavailable copper. The relationship of copper speciation to bioavailability was discerned by measuring total copper (AA), labile copper (ASV) and copper ion activity (ISE) during these sediment toxicity experiments.

  15. Surface structure influences contact killing of bacteria by copper

    PubMed Central

    Zeiger, Marco; Solioz, Marc; Edongué, Hervais; Arzt, Eduard; Schneider, Andreas S

    2014-01-01

    Copper kills bacteria rapidly by a mechanism that is not yet fully resolved. The antibacterial property of copper has raised interest in its use in hospitals, in place of plastic or stainless steel. On the latter surfaces, bacteria can survive for days or even weeks. Copper surfaces could thus provide a powerful accessory measure to curb nosocomial infections. We here investigated the effect of the copper surface structure on the efficiency of contact killing of Escherichia coli, an aspect which so far has received very little attention. It was shown that electroplated copper surfaces killed bacteria more rapidly than either polished copper or native rolled copper. The release of ionic copper was also more rapid from electroplated copper compared to the other materials. Scanning electron microscopy revealed that the bacteria nudged into the grooves between the copper grains of deposited copper. The findings suggest that, in terms of contact killing, more efficient copper surfaces can be engineered. PMID:24740976

  16. Zinc sulfide and zinc selenide immersion gratings for astronomical high-resolution spectroscopy: evaluation of internal attenuation of bulk materials in the short near-infrared region

    NASA Astrophysics Data System (ADS)

    Ikeda, Yuji; Kobayashi, Naoto; Kondo, Sohei; Yasui, Chikako; Kuzmenko, Paul J.; Tokoro, Hitoshi; Terada, Hiroshi

    2009-08-01

    We measure the internal attenuation of bulk crystals of chemical vapor deposition zinc selenide (CVD-ZnS), chemical vapor deposition zinc sulfide (CVD-ZnSe), Si, and GaAs in the short near-infrared (sNIR) region to evaluate the possibility of astronomical immersion gratings with those high refractive index materials. We confirm that multispectral grade CVD-ZnS and CVD-ZnSe are best suited for the immersion gratings, with the smallest internal attenuation of ?att=0.01 to 0.03 cm-1 among the major candidates. The measured attenuation is roughly in proportion to ?-2, suggesting it is dominated by bulk scattering due to the polycrystalline grains rather than by absorption. The total transmittance in the immersion grating is estimated to be at least >80%, even for the spectral resolution of R=300,000. Two potential problems, the scattered light by the bulk material and the degradation of the spectral resolution due to the gradient illumination in the diffracted beam, are investigated and found to be negligible for usual astronomical applications. Since the remaining problem, the difficulty of cutting grooves on CVD-ZnS and CVD-ZnSe, has recently been overcome by the nanoprecision fly-cutting technique, ZnS and ZnSe immersion gratings for astronomy can be technically realized.

  17. Electronic characterization of defects in narrow gap semiconductors: Comparison of electronic energy levels and formation energies in mercury cadmium telluride, mercury zinc telluride, and mercury zinc selenide

    NASA Technical Reports Server (NTRS)

    Patterson, James D.; Li, Wei-Gang

    1995-01-01

    The project has evolved to that of using Green's functions to predict properties of deep defects in narrow gap materials. Deep defects are now defined as originating from short range potentials and are often located near the middle of the energy gap. They are important because they affect the lifetime of charge carriers and hence the switching time of transistors. We are now moving into the arena of predicting formation energies of deep defects. This will also allow us to make predictions about the relative concentrations of the defects that could be expected at a given temperature. The narrow gap materials mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS) are of interest to NASA because they have commercial value for infrared detecting materials, and because there is a good possibility that they can be grown better in a microgravity environment. The uniform growth of these crystals on earth is difficult because of convection (caused by solute depletion just ahead of the growing interface, and also due to thermal gradients). In general it is very difficult to grow crystals with both radial and axial homogeneity.

  18. Cadmium telluride (CdTe) and cadmium selenide (CdSe) leaching behavior and surface chemistry in response to pH and O2.

    PubMed

    Zeng, Chao; Ramos-Ruiz, Adriana; Field, Jim A; Sierra-Alvarez, Reyes

    2015-05-01

    Cadmium telluride (CdTe) and cadmium selenide (CdSe) are increasingly being applied in photovoltaic solar cells and electronic components. A major concern is the public health and ecological risks associated with the potential release of toxic cadmium, tellurium, and/or selenium species. In this study, different tests were applied to investigate the leaching behavior of CdTe and CdSe in solutions simulating landfill leachate. CdTe showed a comparatively high leaching potential. In the Toxicity Characteristic Leaching Procedure (TCLP) and Waste Extraction Test (WET), the concentrations of cadmium released from CdTe were about 1500 and 260 times higher than the regulatory limit (1 mg/L). In contrast, CdSe was relatively stable and dissolved selenium in both leaching tests was below the regulatory limit (1 mg/L). Nonetheless, the regulatory limit for cadmium was exceeded by 5- to 6- fold in both tests. Experiments performed under different pH and redox conditions confirmed a marked enhancement in CdTe and CdSe dissolution both at acidic pH and under aerobic conditions. These findings are in agreement with thermodynamic predictions. Taken as a whole, the results indicate that recycling of decommissioned CdTe-containing devices is desirable to prevent the potential environmental release of toxic cadmium and tellurium in municipal landfills. PMID:25710599

  19. Hydrothermal synthesis of [C 6H 16N 2][In 2Se 3(Se 2)]: A new one-dimensional indium selenide

    NASA Astrophysics Data System (ADS)

    Ewing, Sarah J.; Powell, Anthony V.; Vaqueiro, Paz

    2011-07-01

    A new organically templated indium selenide, [C 6H 16N 2][In 2Se 3(Se 2)], has been prepared hydrothermally from the reaction of indium, selenium and trans-1,4-diaminocyclohexane in water at 170 °C. This material was characterised by single-crystal and powder X-ray diffraction, thermogravimetric analysis, UV-vis diffuse reflectance spectroscopy, FT-IR and elemental analysis. The compound crystallises in the monoclinic space group C2/ c ( a=12.0221(16) Å, b=11.2498(15) Å, c=12.8470(17) Å, ?=110.514(6)°). The crystal structure of [C 6H 16N 2][In 2Se 3(Se 2)] contains anionic chains of stoichiometry [In 2Se 3(Se 2)] 2-, which are aligned parallel to the [1 0 1] direction, and separated by diprotonated trans-1,4-diaminocyclohexane cations. The [In 2Se 3(Se 2)] 2- chains, which consist of alternating four-membered [In 2Se 2] and five-membered [In 2Se 3] rings, contain perselenide (Se 2) 2- units. UV-vis diffuse reflectance spectroscopy indicates that [C 6H 16N 2][In 2Se 3(Se 2)] has a band gap of 2.23(1) eV.

  20. Na3.88Mo15Se19: a novel ternary reduced molybdenum selenide containing Mo6 and Mo9 clusters

    PubMed Central

    Salloum, Diala; Gougeon, Patrick; Gall, Philippe

    2013-01-01

    The structure of tetrasodium penta­deca­molybdenum nona­deca­selenide, Na3.88Mo15Se19, is isotypic with the In3+xMo15Se19 compounds [Grüttner et al. (1979 ?). Acta Cryst. B35, 285–292]. It is characterized by two cluster units, Mo6Sei 8Sea 6 and Mo9Sei 11Sea 6 (where i represents inner and a apical atoms), that are present in a 1:1 ratio. The cluster units are centered at Wyckoff positions 2b and 2c and have point-group symmetry -3 and -6, respectively. The clusters are inter­connected through additional Mo—Se bonds. In the title compound, the Na+ cations replace the trivalent as well as the monovalent indium atoms present in In3.9Mo15Se19. One Mo, one Se and one Na atom are situated on mirror planes, and two other Se atoms and one Na atom [occupancy 0.628?(14)] are situated on threefold rotation axes. The crystal studied was twinned by merohedry with refined components of 0.4216?(12) and 0.5784?(12). PMID:24098158

  1. Copper: Its trade manufacture, use, and environmental status

    SciTech Connect

    Kundig, K.J.A. [ed.; Joseph, G.

    1998-12-31

    Providing a comprehensive overview of the various technical and commercial aspects affecting the role of copper and its use as an engineered material, this book offers representative numerical data collected from industrial sources around the world and also selected from the scientific literature. This book contains more than 270 figures and some 160 tables. Contents include: history of the use of copper; the copper trade; metallurgy and properties of copper and copper alloys; copper products; processing and fabrication; applications of copper and copper alloys; environmental aspects; and an index.

  2. Daily copper supplement effects on copper balance in trained subjects during prolonged restriction of muscular activity.

    PubMed

    Zorbas, Y G; Charapakin, K P; Kakurin, V J; Kuznetsov, N K; Federov, M A; Popov, V K

    1999-08-01

    The aim of this study was to assess the effect of a daily intake of copper supplements on negative copper balance during prolonged exposure to hypokinesia (decreased number of kilometers per day). During hypokinesia (HK), negative copper balance is shown by increased, not by decreased, serum copper concentration, as it happens in other situations. Studies were done during a 30-d prehypokinetic period and a 364-d hypokinetic period. Forty male trained volunteers aged 22-26 yr with a peak oxygen uptake of 66.4 mL/min/kg and with an average of 13.7 km/d running distance were chosen as subjects. They were equally divided into four groups: unsupplemented ambulatory control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented hypokinetic subjects (SHKS), and supplemented ambulatory control subjects (SACS). The SACS and SHKS groups took 0.09 mg copper carbonate/kg body weight daily. The SHKS and UHKS groups were maintained under an average running distance of 1.7 km/d, whereas the SACS and UACS groups did not experience any modifications in their normal training routines. During the 30-d prehypokinetic period and the 346-d hypokinetic period, urinary excretion of copper, calcium, and magnesium and serum concentrations of copper, calcium, and magnesium were measured. Copper loss in feces and copper balance was also determined. In both UHKS and SHKS groups, urinary excretion of copper, calcium, and magnesium and concentrations of copper, magnesium, and calcium in serum increased significantly when compared with the SACS and UACS groups. Loss of copper in feces was also increased significantly in the SHKS and UHKS groups when compared with the UACS and SACS groups. Throughout the study, the copper balance was negative in the SHKS and UHKS groups, whereas in the SACS and UACS groups, the copper balance was positive. It was concluded that a daily intake of copper supplements cannot be used to prevent copper deficiency shown by increased copper concentration. Copper supplements also failed to prevent negative copper balance and copper losses in feces and urine in endurance-trained subjects during prolonged exposure to HK. PMID:10433342

  3. Bioreduction of Cu(II) by Cell-Free Copper Reductase from a Copper Resistant Pseudomonas sp. NA

    Microsoft Academic Search

    Robson Andreazza; Benedict C. Okeke; Simone Pieniz; Adriano Brandelli; Mácio R. Lambais; Flávio A. O. Camargo

    Environmental copper contamination is a serious human health problem. Copper reductase is produced by microorganisms to facilitate\\u000a copper uptake by ATPases into the cells increasing copper biosorption. This study assessed the reduction of Cu(II) by cell-free\\u000a extracts of a highly copper-resistant bacterium, Pseudomonas sp. strain NA, isolated from vineyard soil contaminated with copper. Both intact cells and cell-free extract of

  4. Geomorphology of the lower Copper River, Alaska

    USGS Publications Warehouse

    Brabets, T.P.

    1996-01-01

    The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1996, 11 bridges were located along this section of the highway. These bridges cross parts or all of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. At the peak outflow rate from Van Cleve Lake, the flow of the Copper River will increase an additional 140,000 and 190,000 cubic feet per second. Bedload sampling and continuous seismic reflection were used to show that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lakes, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow- gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake, long-term flow characteristics of the lower Copper River were synthesized. Historical discharge and cross-section data indicate that as late as 1970, most of the flow of the lower Copper River was through the first three bridges of the Copper River Highway as it begins to traverse the alluvial flood plain. In the mid 1980's, a percentage of the flow had shifted away from these three bridges and in 1995, only 51 percent of the flow of the Copper River passed through them. Eight different years of aerial photography of the lower Copper River were analyzed using Geographical Information System techniques. This analysis indicated that no major channel changes were caused by the 1964 earthquake. A flood in 1981 that had a recurrence interval of more than 100 years caused significant channel changes in the lower Copper River. A probability analysis of the lower Copper River indicated stable areas and the long-term locations of channels. By knowing the number of times a particular area has been occupied by water and the last year an area was occupied by water, areas of instability can be located. A Markov analysis of the lower Copper River indicated that the tendency of the flood plain is to remain in its current state. Large floods of the magnitude of the 1981 event are believed to be the cause of major changes in the lower Copper River.

  5. Antiangiogenic therapy through copper chelation.

    PubMed

    Sproull, Mary; Brechbiel, Martin; Camphausen, Kevin

    2003-06-01

    As new compounds are being evaluated for use in clinical trials involving antiangiogenic therapies, two important factors must be considered. Independent of clinical efficacy, the potential drug must be cost-effective and have reasonable ease of production. The compound endostatin (Entremed, Inc.) has recently completed two Phase I trials with minimal toxicity to the patients treated [1,2]. However, due to the difficulty and expense of producing large quantities of a recombinant protein, Entremed Inc. has experienced financial difficulties [3]. As this company's fate indicates, a drug must not only be clinically effective, but must also possess reasonable production economics. Another interesting component of compound development is selectivity. Highly selective antiangiogenic compounds such as the tyrosine kinase inhibitor SU-5416 are being replaced by less selective compounds such as SU-6668, which acts on a broader spectrum of tyrosine kinase receptors [4]. This move towards using less selective antiangiogenic compounds is based on preclinical models that demonstrate both better clinical efficacy when using less specific molecules and low response rates from the more selective compounds. With the aim of further examining broadly-acting antiangiogenic agents, the authors are currently evaluating new classes of agents that preferentially bind copper and inhibit angiogenesis. Copper has been known to be a significant target for antiangiogenic therapy for a number of years [5]. Recently, through the use of molecular techniques, the target enzymes that utilise copper as a cofactor are being elucidated. This review will describe the historical use of anticopper therapy for the treatment of Wilson's disease and evaluate some of the new anticopper compounds currently under consideration for use in antiangiogenic therapy. PMID:12783576

  6. Excitonic superconductivity in copper oxides

    SciTech Connect

    Tesanovic, Z.; Bishop, A.R.; Martin, R.L.; Harris, C.

    1988-01-01

    We discuss the possibility of excitonic superconductivity in high T/sub c/ copper oxides. The Hamiltonians describing CuO/sub 2/ planes supports both antiferromagnetism and low-lying Cu /longleftrightarrow/ O intra- and interband charge fluctuations. One crosses from one regime to another as the number of holes per unit cell increases. The high T/sub c/ superconductivity takes place at hole concentrations most favorable for intraband charge transfer excitations. The dynamic polarizability of the environment surrounding CuO/sub 2/ planes plays an important role in enhancing T/sub c/. 15 refs., 4 figs.

  7. Common Sense Copper and RF Guns

    SciTech Connect

    Mulhollan, G.

    2005-01-18

    The purpose of this document is to gather together both fundamental information on copper and on the cleaning and operation of copper in RF gun structures. While incomplete, this is a living document and will be added to and updated as necessary.

  8. Electrolytic Corrosion of Iron and Copper

    Microsoft Academic Search

    W. F. Higgins

    1954-01-01

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

  9. Reversibleirreversible plasticity transition in twinned copper nanopillars

    E-print Network

    Ghoniem, Nasr M.

    Reversible­irreversible plasticity transition in twinned copper nanopillars J.A. Brown, N 31 October 2009 Abstract Through computer simulations, we show that plasticity in twinned copper nanopillar under compression, plastic deformation can be totally reversed when rR is in the range 0:5 6 rR 6

  10. Biosorption of copper by fungal melanin

    Microsoft Academic Search

    Geoffrey M. Gadd; Louise de Rome

    1988-01-01

    Melanin obtained from Aureobasidium pullulans and Cladosporium resinae was an efficient biosorbent for copper. Copper uptake could be expressed using various adsorption isotherms; melanin from A. pullulans obeyed Freundlich and Langmuir isotherms whereas C. resinae melanin followed the BET isotherm indicating a more complex type of adsorption than in A. pullulans. In general, uptake capacities of melanin were greater than

  11. CONTROL OF COPPER SMELTER FUGITIVE EMISSIONS

    EPA Science Inventory

    This report deals with fugitive emissions from copper smelting and with related emission control measures. The study involved evaluation of the controls now used in the copper smelting industry and development of suggestions for alternative control devices and practices. A brief ...

  12. Efficient copper-vapor pulsed laser

    NASA Technical Reports Server (NTRS)

    Russell, G. R.; Nerheim, N. M.; Pivirotto, T. J.

    1977-01-01

    High velocity flow is attained within system by expanding heated mixture of copper vapor, argon, and helium through supersonic nozzle. Arc heater, operated on argon/helium mixture, supplies energy to vaporize copper and to produce high temperature supersonic flow of gas/vapor mixture.

  13. Inheritance of copper toxicosis in Bedlington terriers.

    PubMed

    Johnson, G F; Sternlieb, I; Twedt, D C; Grushoff, P S; Scheinberg, I

    1980-11-01

    The mode of transmission of copper toxicosis, previously reported to be associated with progressive hepatic disease in certain Bedlington Terriers, has been studied by means of 5 matings involving affected and unaffected Bedlington Terriers and dogs of different breeds. The abnormally large concentration of hepatic copper underlying the disorder was found to follow an autosomal recessive pattern of inheritance. PMID:7212417

  14. Electricity's Part in Open Cut Copper Mining

    Microsoft Academic Search

    R. J. Corfield

    1931-01-01

    This paper is intended to describe the electrification of the world's largest open cut copper mine, and also covers briefly main line transportation and miscellaneous uses of electrical energy at the concentrating plants, that are located approximately 18 miles from the mine. This electrification project was an economical and progressive step in copper mining and developed some very interesting engineering

  15. Copper uptake by the water hyacinth

    Microsoft Academic Search

    Terrence A. Lee; James K. Hardy

    1987-01-01

    Factors affecting Cu uptake by the water hyacinth (Eichornia crassipes) were examined. Two phases of copper uptake were observed throughout the uptake range (1–1000 mg\\/1). An initial rapid uptake phase of 4 hours followed by a slower, near linear uptake phase extending past 48 hours was observed. Stirring the solution enhanced uptake, suggesting copper removal is partially diffusion limited. Variations

  16. COPPER PITTING AND PINHOLE LEAK RESEARCH STUDY

    EPA Science Inventory

    Localized copper corrosion or pitting is a significant problem at many water utilities across the United States. Copper pinhole leak problems resulting from extensive pitting are widely under reported. Given the sensitive nature of the problem, extent of damage possible, costs o...

  17. Lack of effects of copper gluconate

    Microsoft Academic Search

    William B Pratt; John L Omdahl; John RJ Sorenson

    A double-blind study was done giving 10 mg ofcopper\\/day as copper gluconate or placebo capsules for 12 wk. The seven subjects receiving copper gluconate had no change in the level ofcopper in the serum, urine, or hair. There was also no change in the levels ofzinc or magnesium. There was also no significant change in levels of hematocrit, triglyceride, SOOT,

  18. Cu2Se nanoparticles with tunable electronic properties due to a controlled solid-state phase transition driven by copper oxidation and cationic conduction.

    PubMed

    Riha, Shannon C; Johnson, Derek C; Prieto, Amy L

    2011-02-01

    Stoichiometric copper(I) selenide nanoparticles have been synthesized using the hot injection method. The effects of air exposure on the surface composition, crystal structure, and electronic properties were monitored using X-ray photoelectron spectroscopy, X-ray diffraction, and conductivity measurements. The current-voltage response changes from semiconducting to ohmic, and within a week a 3000-fold increase in conductivity is observed under ambient conditions. The enhanced electronic properties can be explained by the oxidation of Cu(+) and Se(2-) on the nanoparticle surface, ultimately leading to a solid-state conversion of the core from monoclinic Cu(2)Se to cubic Cu(1.8)Se. This behavior is a result of the facile solid-state ionic conductivity of cationic Cu within the crystal and the high susceptibility of the nanoparticle surface to oxidation. This regulated transformation is appealing as one could envision using layers of Cu(2)Se nanoparticles as both semiconducting and conducting domains in optoelectronic devices simply by tuning the electronic properties for each layer through controlled oxidation. PMID:21033686

  19. Molecular responses of mouse macrophages to copper and copper oxide nanoparticles inferred from proteomic analyses.

    PubMed

    Triboulet, Sarah; Aude-Garcia, Catherine; Carrière, Marie; Diemer, Hélène; Proamer, Fabienne; Habert, Aurélie; Chevallet, Mireille; Collin-Faure, Véronique; Strub, Jean-Marc; Hanau, Daniel; Van Dorsselaer, Alain; Herlin-Boime, Nathalie; Rabilloud, Thierry

    2013-11-01

    The molecular responses of macrophages to copper-based nanoparticles have been investigated via a combination of proteomic and biochemical approaches, using the RAW264.7 cell line as a model. Both metallic copper and copper oxide nanoparticles have been tested, with copper ion and zirconium oxide nanoparticles used as controls. Proteomic analysis highlighted changes in proteins implicated in oxidative stress responses (superoxide dismutases and peroxiredoxins), glutathione biosynthesis, the actomyosin cytoskeleton, and mitochondrial proteins (especially oxidative phosphorylation complex subunits). Validation studies employing functional analyses showed that the increases in glutathione biosynthesis and in mitochondrial complexes observed in the proteomic screen were critical to cell survival upon stress with copper-based nanoparticles; pharmacological inhibition of these two pathways enhanced cell vulnerability to copper-based nanoparticles, but not to copper ions. Furthermore, functional analyses using primary macrophages derived from bone marrow showed a decrease in reduced glutathione levels, a decrease in the mitochondrial transmembrane potential, and inhibition of phagocytosis and of lipopolysaccharide-induced nitric oxide production. However, only a fraction of these effects could be obtained with copper ions. In conclusion, this study showed that macrophage functions are significantly altered by copper-based nanoparticles. Also highlighted are the cellular pathways modulated by cells for survival and the exemplified cross-toxicities that can occur between copper-based nanoparticles and pharmacological agents. PMID:23882024

  20. Copper accumulation in channel catfish (Ictalurus punctatus) exposed to water borne copper sulfate

    SciTech Connect

    Hobbs, M. [Oak Ridge Inst. for Science and Education, TN (United States); Griffin, B. [National Biological Service, Stuttgart, AR (United States); Schlenk, D. [Univ. of Mississippi, Oxford, MS (United States); Kadlubar, F.; Brand, C.D. [National Center for Toxicological Research, Jefferson, AR (United States)

    1995-12-31

    Liver and axial muscle of channel catfish (Ictalurus punctatus) was analyzed for residual copper after exposure to water borne copper sulfate. Copper sulfate was continuously introduced into well water in three fiber glass tanks to achieve 1.7 mg/L, 2.7 mg/L and 3.6 mg/L copper sulfate concentrations in exposure waters. Milli-Q quality water was metered into a fourth tank at the same rate for unexposed fish. Actual levels of copper in exposure waters were determined by daily sampling and analysis by graphite furnace atomic absorption spectrophotometry (GFAA). Tissue samples were taken from six fish from each of the exposed and unexposed tanks at two-week intervals, Samples were collected until tissue analysis indicated an equilibrium had been established between the uptake and elimination in both the muscle and liver tissue. Elimination was followed until a clear rate of deputation could be established. Samples were digested in nitric acid in a micro wave digestor and analyzed by GFAA. Results of tissue analysis will be presented to demonstrate bioaccumulation and the effect of copper concentration, length of copper exposure, and gender on copper uptake, establishment of tissue:environmental copper equilibrium, and rate of copper elimination following exposure.

  1. Molecular Responses of Mouse Macrophages to Copper and Copper Oxide Nanoparticles Inferred from Proteomic Analyses*

    PubMed Central

    Triboulet, Sarah; Aude-Garcia, Catherine; Carrière, Marie; Diemer, Hélène; Proamer, Fabienne; Habert, Aurélie; Chevallet, Mireille; Collin-Faure, Véronique; Strub, Jean-Marc; Hanau, Daniel; Van Dorsselaer, Alain; Herlin-Boime, Nathalie; Rabilloud, Thierry

    2013-01-01

    The molecular responses of macrophages to copper-based nanoparticles have been investigated via a combination of proteomic and biochemical approaches, using the RAW264.7 cell line as a model. Both metallic copper and copper oxide nanoparticles have been tested, with copper ion and zirconium oxide nanoparticles used as controls. Proteomic analysis highlighted changes in proteins implicated in oxidative stress responses (superoxide dismutases and peroxiredoxins), glutathione biosynthesis, the actomyosin cytoskeleton, and mitochondrial proteins (especially oxidative phosphorylation complex subunits). Validation studies employing functional analyses showed that the increases in glutathione biosynthesis and in mitochondrial complexes observed in the proteomic screen were critical to cell survival upon stress with copper-based nanoparticles; pharmacological inhibition of these two pathways enhanced cell vulnerability to copper-based nanoparticles, but not to copper ions. Furthermore, functional analyses using primary macrophages derived from bone marrow showed a decrease in reduced glutathione levels, a decrease in the mitochondrial transmembrane potential, and inhibition of phagocytosis and of lipopolysaccharide-induced nitric oxide production. However, only a fraction of these effects could be obtained with copper ions. In conclusion, this study showed that macrophage functions are significantly altered by copper-based nanoparticles. Also highlighted are the cellular pathways modulated by cells for survival and the exemplified cross-toxicities that can occur between copper-based nanoparticles and pharmacological agents. PMID:23882024

  2. Structural properties of Cu(In,Ga)Se 2 thin films prepared from chemically processed precursor layers

    Microsoft Academic Search

    C. J. Hibberd; M. Ganchev; M. Kaelin; S. E. Dann; G. Bilger; H. U. Upadhyaya; A. N. Tiwari

    2009-01-01

    We have developed a chemical process for incorporating copper into indium gallium selenide layers with the goal of creating a precursor structure for the formation of copper indium gallium diselenide (CIGS) photovoltaic absorbers. Stylus profilometry, EDX, Raman spectroscopy, XRD and SIMS measurements show that when indium gallium selenide layers are immersed in a hot copper chloride solution, copper is incorporated

  3. THE IMPACT OF ORTHOPHOSPHATE ON COPPER CORROSION AND CHLORINE DEMAND

    EPA Science Inventory

    In 1991, EPA promulgated the Lead and Copper Rule, which established a copper action level of 1.3 mg/L in a 1-liter, first-draw sample collected from the consumer?s tap. Excessive corrosion of copper can lead to elevated copper levels at the consumer's tap, and in some cases, can...

  4. 7 CFR 1755.403 - Copper cable telecommunications plant measurements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Copper cable telecommunications plant measurements...STANDARD CONTRACT FORMS § 1755.403 Copper cable telecommunications plant measurements... 0.53 Where: Column A-10 mil Copper shield. Column B—5 mil Copper...

  5. THE EFFECT OF AUFWUCHS COPPER ON SPAT SETTLEMENT OF THE

    E-print Network

    District of Columbia, University of the

    #12;#12;THE EFFECT OF AUFWUCHS COPPER ON SPAT SETTLEMENT OF THE OYSTER, CRASSOSTERA VIRGINICA Dr States Government." #12;THE EFFECT OF AUFWUCKS COPPER ON SPAT SETTLEMENT OF THE OYSTER, CRASSOSTREA is copper. Copper is used specifically as an antifouling agent on ship bottoms. Crisp and Austin (1960

  6. 7 CFR 1755.403 - Copper cable telecommunications plant measurements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Copper cable telecommunications plant measurements...STANDARD CONTRACT FORMS § 1755.403 Copper cable telecommunications plant measurements... 0.53 Where: Column A-10 mil Copper shield. Column B—5 mil Copper...

  7. 7 CFR 1755.403 - Copper cable telecommunications plant measurements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Copper cable telecommunications plant measurements...STANDARD CONTRACT FORMS § 1755.403 Copper cable telecommunications plant measurements... 0.53 Where: Column A-10 mil Copper shield. Column B—5 mil Copper...

  8. Formation of Metallic Copper Nanoparticles at the Soil-Root

    E-print Network

    Illinois at Chicago, University of

    Formation of Metallic Copper Nanoparticles at the Soil-Root Interface A L A I N M A N C E A U. Accepted December 10, 2007. Copper is an essential element in the cellular electron- transport chain copper toxicity. Plants diminish excess copper in two structural regions: rare hyperaccumulators bind

  9. 7 CFR 1755.403 - Copper cable telecommunications plant measurements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Copper cable telecommunications plant measurements...STANDARD CONTRACT FORMS § 1755.403 Copper cable telecommunications plant measurements... 0.53 Where: Column A-10 mil Copper shield. Column B—5 mil Copper...

  10. COPPER--1999 22.1 By Daniel E. Edelstein

    E-print Network

    COPPER--1999 22.1 COPPER By Daniel E. Edelstein Domestic survey data and tables were prepared. In 1999, mine production of recoverable copper in the United States continued its downward slide to mine closures announced in 1998 that carried forward into 1999, low refined copper prices led

  11. COPPER--2003 21.1 By Daniel L. Edelstein

    E-print Network

    COPPER--2003 21.1 COPPER By Daniel L. Edelstein Domestic survey data and tables were prepared copper products; one of the refineries operated for only a portion of the year. Scrap was also consumed declined by about 50,000 t to 2.25 Mt owing to the dismantling of Cerro Copper Products secondary refinery

  12. COPPER--2000 23.1 By Daniel L. Edelstein

    E-print Network

    COPPER--2000 23.1 COPPER By Daniel L. Edelstein Domestic survey data and tables were prepared. In 2000, mine production of recoverable copper in the United States continued its downward slide to mine closures and cutbacks carried forward from midyear 1999, high energy costs coupled with low copper

  13. COPPER--1998 22.1 By Daniel L. Edelstein

    E-print Network

    COPPER--1998 22.1 COPPER By Daniel L. Edelstein Domestic survey data and tables were prepared of recoverable copper in the United States reversed its decade-long upward trend, declining by about 80,000 metric tons to the lowest level since 1995. Mine cutbacks and closures were attributed to low copper

  14. Electronic Characterization of Defects in Narrow Gap Semiconductors-Comparison of Electronic Energy Levels and Formation Energies in Mercury Cadmium Telluride, Mercury Zinc Telluride, and Mercury Zinc Selenide

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1996-01-01

    We have used a Green's function technique to calculate the energy levels and formation energy of deep defects in the narrow gap semiconductors mercury cadmium telluride (MCT), mercury zinc telluride (MZT) and mercury zinc selenide (MZS). The formation energy is calculated from the difference between the total energy with an impurity cluster and the total energy for the perfect crystal. Substitutional (including antisite), interstitial (self and foreign), and vacancy deep defects are considered. Relaxation effects are calculated (with molecular dynamics). By use of a pseudopotential, we generalize the ideal vacancy model so as to be able to consider relaxation for vacancies. Different charge states are considered and the charged state energy shift (as computed by a modified Haldane-Anderson model) can be twice that due to relaxation. Different charged states for vacancies were not calculated to have much effect on the formation energy. For all cases we find deep defects in the energy gap only for cation site s-like orbitals or anion site p-like orbitals, and for the substitutional case only the latter are appreciably effected by relaxation. For most cases for MCT, MZT, MZS, we consider x (the concentration of Cd or Zn) in the range appropriate for a band gap of 0.1 eV. For defect energy levels, the absolute accuracy of our results is limited, but the precision is good, and hence chemical trends are accurately predicted. For the same reason, defect formation energies are more accurately predicted than energy level position. We attempt, in Appendix B, to calculate vacancy formation energies using relatively simple chemical bonding ideas due to Harrison. However, these results are only marginally accurate for estimating vacancy binding energies. Appendix C lists all written reports and publications produced for the grant. We include abstracts and a complete paper that summarizes our work which is not yet available.

  15. Structural, magnetic, and electronic properties of iron selenide Fe6-7Se8 nanoparticles obtained by thermal decomposition in high-temperature organic solvents.

    PubMed

    Lyubutin, I S; Lin, Chun-Rong; Funtov, K O; Dmitrieva, T V; Starchikov, S S; Siao, Yu-Jhan; Chen, Mei-Li

    2014-07-28

    Iron selenide nanoparticles with the NiAs-like crystal structure were synthesized by thermal decomposition of iron chloride and selenium powder in a high-temperature organic solvent. Depending on the time of the compound processing at 340?°C, the nanocrystals with monoclinic (M)-Fe3Se4 or hexagonal (H)-Fe7Se8 structures as well as a mixture of these two phases can be obtained. The magnetic behavior of the monoclinic and hexagonal phases is very different. The applied-field and temperature dependences of magnetization reveal a complicated transformation between ferrimagnetic (FRM) and antiferromagnetic (AFM) structures, which can be related to the spin rotation process connected with the redistribution of cation vacancies. From XRD and Mössbauer data, the 3c type superstructure of vacancy ordering was found in the hexagonal Fe7Se8. Redistribution of vacancies in Fe7Se8 from random to ordered leads to the transformation of the magnetic structure from FRM to AFM. The Mössbauer data indicate that vacancies in the monoclinic Fe3Se4 prefer to appear near the Fe(3+) ions and stimulate the magnetic transition with the rotation of the Fe(3+) magnetic moments. Unusually high coercive force Hc was found in both (H) and (M) nanocrystals with the highest ("giant") value of about 25 kOe in monoclinic Fe3Se4. This is explained by the strong surface magnetic anisotropy which is essentially larger than the core anisotropy. Such a large coercivity is rare for materials without rare earth or noble metal elements, and the Fe3Se4-based compounds can be the low-cost, nontoxic alternative materials for advanced magnets. In addition, an unusual effect of "switching" of magnetization in a field of 10 kOe was found in the Fe3Se4 nanoparticles below 280 K, which can be important for applications. PMID:25084934

  16. Cytochemical detection of inherited copper toxicosis of Bedlington terriers.

    PubMed

    Johnson, G F; Gilbertson, S R; Goldfischer, S; Grushoff, P S; Sternlieb, I

    1984-01-01

    Sections of paraffin-embedded specimens of liver obtained from Bedlington terriers were stained with rhodanine for copper and examined and graded by two pathologists. Their results correlated well with each other, as well as with the results of quantitative determinations of hepatic copper content. Copper toxicosis was established by cytochemistry in 20 of 21 specimens, indicating a sensitivity of 95%. The method is highly specific--none of the 19 specimens obtained from unaffected dogs displayed copper-containing granules suggestive of copper toxicosis. Copper cytochemistry appears to be a satisfactory substitute for chemical analysis of hepatic copper content. PMID:6710813

  17. Cytological detection of copper for the diagnosis of inherited copper toxicosis in Bedlington terriers.

    PubMed

    Teske, E; Brinkhuis, B G; Bode, P; van den Ingh, T S; Rothuizen, J

    1992-07-11

    The reliability of a cytological examination of impression smears of the liver was investigated in 89 Bedlington terriers by using the rubeanic acid staining method for copper and comparing the results with the results of a histological examination. Histological examination revealed copper accumulation in the liver of 24 dogs. The cytological method had a sensitivity of 0.96 for detecting copper toxicosis and a specificity of 1.0. When a grading system for the amount of copper was applied, the coefficient of correlation (r) between the cytological and histological techniques was 0.917 (P less than 0.0001). It was concluded that a cytological examination of impression smears stained with rubeanic acid for copper offers a rapid and reliable method for the detection of copper toxicosis in Bedlington terriers. PMID:1380748

  18. The apparent copper complexing capacity of seawater and the interaction of copper with humic matter

    NASA Astrophysics Data System (ADS)

    Sun, Mingyi

    1985-12-01

    The anodic stripping voltammetry with physically-coating mercury film electrode was used to investigate the complexing action of trace heavy metals in seawater with organic ligands. The apparent copper complexing capacity of seawater was determined by titrating the organic ligands in natural seawater with standard ionic copper solution. The complexing actions of copper in seawater with humic acid (HA) or fulvic acid (FA) were investigated by titrating copper in seawater with HA or FA solution. The equilibrium time, electrodeposition potential, and effect of pH etc. were investigated respectively. The results show that the interaction of copper in seawater with organic matter is a fast process. At natural pH, HA or FA tend to act with copper in seawater to form nonlabile complexes. During experimental electrode process, these complexes did not significantly dissociate. The experimental results were calculated according to 1?1 complex formation.

  19. Copper toxicosis in an Australian child.

    PubMed

    Walker, N I

    1999-06-28

    A 20 month old Caucasian child living in rural Australia presented with liver failure after exposure from birth to milk formula made from acidic bore water containing excess copper leached from the copper piping. The liver pathology was identical to that seen in Indian childhood cirrhosis and similar disease in non-Indian children now termed idiopathic copper toxicosis (ICT). The only other Australian case, reported more than 20 years previously, had identical presentation, pathology and circumstances of occurrence. The rarity of ICT in Australia, despite a significant population at risk, and the implications of these cases are discussed. PMID:10383881

  20. Nanosecond pulsed laser blackening of copper

    NASA Astrophysics Data System (ADS)

    Tang, Guang; Hourd, Andrew C.; Abdolvand, Amin

    2012-12-01

    Nanosecond (12 ns) pulsed laser processing of copper at 532 nm resulted in the formation of homogenously distributed, highly organized microstructures. This led to the fabrication of large area black copper substrates with absorbance of over 97% in the spectral range from 250 nm to 750 nm, and a broadband absorbance of over 80% between 750 nm and 2500 nm. Optical and chemical analyses of the fabricated black metal are presented and discussed. The employed laser is an industrially adaptable source and the presented technique for fabrication of black copper could find applications in broadband thermal radiation sources, solar energy absorbers, irradiative heat transfer devices, and thermophotovoltaics.

  1. Copper complexes with bioactive ligands

    Microsoft Academic Search

    B. Dudová; D. Hudecová; R. Pokorný; M. Mikulášová; M. Palicová; P. Segla; M. Melník

    2001-01-01

    Biological properties of new copper(II) complexes of 2-methylthionicotinate (2-MeSNic) of composition Cu(2-MeSNic)2(MeNia)2·4H2O (where MeNia isN-methylnicotinamide), Cu(2-MeSNic)2(Nia)2·2H2O (where Nia is nicotinamide) and Cu(2-MeSNic)2(2 (where L is isonicotinamide (iNia) or ethyl nicotinate (EtNic)) are reported. Gram?-bacteria (Escherichia coli) are more resistant against Cu(II) complexes than Gram+-bacteria (Staphylococcus aureus)—significant antistaphylococcal activity was found with Cu(2-MeSNic)2(MeNia)2·4H2O (IC50 1.3 mmol\\/L).Caddida parapsilosis was most inhibited by

  2. Copper Homeostasis in Mycobacterium tuberculosis

    PubMed Central

    Shi, Xiaoshan; Darwin, K. Heran

    2015-01-01

    Copper (Cu) is a trace element essential for the growth and development of almost all organisms, including bacteria. However, Cu overload in most systems is toxic. Studies show Cu accumulates in macrophage phagosomes infected with bacteria, suggesting Cu provides an innate immune mechanism to combat invading pathogens. To counteract the host-supplied Cu, increasing evidence suggests that bacteria have evolved Cu resistance mechanisms to facilitate their pathogenesis. In particular, Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, has evolved multiple pathways to respond to Cu. Here, we summarize what is currently known about Cu homeostasis in Mtb and discuss potential sources of Cu encountered by this and other pathogens in a mammalian host. PMID:25614981

  3. Copper: Toxicological relevance and mechanisms

    PubMed Central

    Gaetke, Lisa M.; Chow-Johnson, Hannah S.; Chow, Ching K.

    2015-01-01

    Copper (Cu) is a vital mineral essential for many biological processes. The vast majority of all Cu in healthy humans is associated with enzyme prosthetic groups or bound to proteins. Cu homeostasis is tightly regulated through a complex system of Cu transporters and chaperone proteins. Excess or toxicity of Cu, which is associated with the pathogenesis of hepatic disorder, neurodegenerative changes and other disease conditions, can occur when Cu homeostasis is disrupted. The capacity to initiate oxidative damage is most commonly attributed to Cu-induced cellular toxicity. Recently, altered cellular events, including lipid metabolism, gene expression, alpha-synuclein aggregation, activation of acidic sphingomyelinase and release of ceramide, and temporal and spatial distribution of Cu in hepatocytes, as well as Cu-protein interaction in the nerve system, have been suggested to play a role in Cu toxicity. However, whether these changes are independent of, or secondary to, an altered cellular redox state of Cu remain to be elucidated. PMID:25199685

  4. Copper homeostasis in Mycobacterium tuberculosis.

    PubMed

    Shi, Xiaoshan; Darwin, K Heran

    2015-06-10

    Copper (Cu) is a trace element essential for the growth and development of almost all organisms, including bacteria. However, Cu overload in most systems is toxic. Studies show Cu accumulates in macrophage phagosomes infected with bacteria, suggesting Cu provides an innate immune mechanism to combat invading pathogens. To counteract the host-supplied Cu, increasing evidence suggests that bacteria have evolved Cu resistance mechanisms to facilitate their pathogenesis. In particular, Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, has evolved multiple pathways to respond to Cu. Here, we summarize what is currently known about Cu homeostasis in Mtb and discuss potential sources of Cu encountered by this and other pathogens in a mammalian host. PMID:25614981

  5. Three stages of copper accumulation in hepatocellular lysosomes: X-ray microanalysis of copper-loaded golden hamsters.

    PubMed Central

    Yagi, A.; Hayashi, H.; Higuchi, T.; Hishida, N.; Sakamoto, N.

    1992-01-01

    Male golden hamsters were loaded with copper by supplying them for up to 12 weeks with drinking water containing 0.5% cupric acetate. The copper feeding increased hepatic copper to widely varying levels. Energy dispersive X-ray microanalysis could always identify a copper-sulphur complex in the hepatocyte lysosomes of copper-loaded hamsters and the X-ray intensity of copper was found to be a reliable parameter to measure in-situ copper accumulation. Combining this parameter with the copper binding ratio expressed by delta Cu/delta S enabled us to discern two stages of sub-histochemical copper accumulation. The first stage was marked by low levels of both lysosomal copper and binding ratio, which suggested that this initial copper transfer was mediated by unsaturated cuproproteins. The second stage was characterized by median amounts of lysosomal copper and a binding ratio of more than 0.50. At the third stage, histochemically detectable copper appeared in animals whose lysosomal copper was extraordinarily high in later experimental periods. With the copper binding ratio being in the same range of 0.50-0.83, it seemed that saturated cuproproteins were the main mediator of copper transport in the later two stages. Images Fig. 2 PMID:1576079

  6. Integrated chip-scale simulation of pattern dependencies in copper electroplating and copper chemical mechanical polishing processes

    Microsoft Academic Search

    Tamba E. Tugbawa; Tae H. Park; Duane S. Boning

    2002-01-01

    We present a characterization and modeling methodology for chip-level simulation of pattern dependencies in the fabrication of copper interconnects. The methodology integrates semi-empirical models for copper CMP and copper plating processes, and uses a specialized test mask and design of experiments for calibration purposes. We demonstrate the methodology with a four step copper CMP process and a superfill electroplating technology

  7. The apparent copper complexing capacity of seawater and the interaction of copper with humic matter

    Microsoft Academic Search

    Mingyi Sun

    1985-01-01

    The anodic stripping voltammetry with physically-coating mercury film electrode was used to investigate the complexing action\\u000a of trace heavy metals in seawater with organic ligands. The apparent copper complexing capacity of seawater was determined\\u000a by titrating the organic ligands in natural seawater with standard ionic copper solution. The complexing actions of copper\\u000a in seawater with humic acid (HA) or fulvic

  8. Comparative efficacy of several potential treatments for copper mobilization in copper-overloaded rats

    Microsoft Academic Search

    Jose L. Domingo; Mercedes Gómez; Mark M. Jones

    2000-01-01

    d-Penicillamine (DPA) is effective in the treatment of Wilson’s disease, whereas zinc salts are also used as a therapy for\\u000a this disorder of copper transport. Recently, it has been shown that the copper chelators 1,4,7,11-tetraazaundecane tetrahydrochloride\\u000a (TAUD) and tetraethylenepentamine pentahydrochloride (TETREN) could be useful for copper mobilization in rats. Because these\\u000a agents could be potential clinical alternatives to DPA for

  9. X-Ray Diffraction Studies of Copper Nanopowder

    E-print Network

    T. Theivasanthi; M. Alagar

    2010-03-31

    Copper nanopowder preparation and its X-Ray diffraction studies are reported in this paper. Electrolytic cathode deposition method is simple and cheapest process for its preparation. Copper nanopowder has been prepared from aqueous copper sulphate solution. Wide range of experimental conditions has been adopted in this process and its X-Ray diffraction characterizations have been studied. The results confirming copper nanopowder with size below 30 nm. Uniformed size Copper nanopowder preparation, in normal room temperature is importance of this study.

  10. Nonoxidative copper nano and fine particles for electroconductive materials

    Microsoft Academic Search

    Tetsu Yonezawa; Hiroki Tsukamoto; Takashi Narushima

    2011-01-01

    Metallic copper nano and fine particles have been successfully prepared by a wet process using a biopolymer as an anti-oxidation reagent. Copper oxide (CuO) and copper sulfate (CuSO4) were the metal sauces used in this study. Hydrazine was used as the reducing reagent in order to obtain copper metal atoms. Uniform sized metallic copper particles were obtained by this process.

  11. Study on film forming organo-copper polymer

    Microsoft Academic Search

    A. B. Samui; J. G. Chavan; V. R. Hande

    2006-01-01

    Film forming organo-copper polymer was synthesized from diethanol amine. The organo-copper polymer (copper salt of polyester amide) contains long chain amide in the side group. The intermediates and the final products were characterized for chemical structure, molecular weight, copper content, curing and thermal properties of cured resin. Organo-copper polymer was used as soluble resin to formulate a coating. Mechanical strength

  12. Effect of zinc supplementation on bovine plasma copper

    Microsoft Academic Search

    N. R. Towers; P. W. Young; D. E. Wright

    1981-01-01

    Zinc sulphate was added to the drinking water of Angus cows and calves grazing an area considered marginal for copper nutrition of cattle. Mean daily intakes of approximately 12–15 mg Zn\\/kg live-weight further depressed already low plasma copper concentrations to levels considered to indicate copper deficiency. The plasma copper concentrations in untreated animals increased during the trial indicating adequate copper

  13. Functional understanding of the versatile protein copper metabolism MURR1 domain 1 (COMMD1) in copper homeostasis.

    PubMed

    Fedoseienko, Alina; Bartuzi, Paulina; van de Sluis, Bart

    2014-05-01

    Copper is an important cofactor in numerous biological processes in all living organisms. However, excessive copper can be extremely toxic, so it is vital that the copper level within a cell is tightly regulated. The damaging effect of copper is seen in several hereditary forms of copper toxicity in humans and animals. At present, Wilson's disease is the best-described and best-studied copper-storage disorder in humans; it is caused by mutations in the ATP7B gene. In dogs, a mutation in the COMMD1 gene has been found to be associated with copper toxicosis. Using a liver-specific Commd1 knockout mouse, the biological role of Commd1 in copper homeostasis has been confirmed. Yet, the exact mechanism by which COMMD1 regulates copper homeostasis is still unknown. Here, we give an overview of the current knowledge and perspectives on the molecular function of COMMD1 in copper homeostasis. PMID:24697840

  14. Copper release from copper nanoparticles in the presence of natural organic matter.

    PubMed

    Wang, Long-Fei; Habibul, Nuzahat; He, Dong-Qin; Li, Wen-Wei; Zhang, Xing; Jiang, Hong; Yu, Han-Qing

    2015-01-01

    Copper nanoparticles (CuNPs) are widely used and inevitably released into aqueous environments, causing ecological and health risks. Ubiquitous natural organic matter (NOM) might affect the copper release behaviors from CuNPs and their toxicity. This work aims to elucidate how NOM affects copper release from CuNPs, with a focus on the impacts of NOM properties and the NOM-CuNPs interaction mechanism. The copper release kinetics and different copper fractions induced by representative NOMs were characterized. The presence of NOM led to a more dispersive state of CuNPs clusters. Copper release mainly resulted from complexation reactions between CuNPs and functional groups of NOM. Humic substances were more effective in releasing copper than sodium alginate and bovine serum albumin, due to a higher amount of functional groups and lower molecular weight, which facilitated the contact and complexion reactions. Chlorination treatment of NOM significantly decelerated copper release due to the destruction of functional groups and less attachment of NOM. However, the copper releasing ability of humic acid was not substantially affected by Ca²?-induced coagulation. This study provides better understanding about the persistence and transformation of CuNPs in aquatic environments. PMID:25462713

  15. Modification of Phenolic Oximes for Copper Extraction 

    E-print Network

    Forgan, Ross Stewart

    2008-01-01

    The thesis deals with the modification of salicylaldoxime-based reagents used in hydrometallurgical extraction, addressing rational ligand design to tune copper(II) extractant strengths and also the development of reagents ...

  16. Electrolytic remediation of chromated copper arsenate wastes

    E-print Network

    Stern, Heather A. G. (Heather Ann Ganung)

    2006-01-01

    While chromated copper arsenate (CCA) has proven to be exceptionally effective in protecting wood from rot and infestation, its toxic nature has led to the problem of disposal of CCA-treated lumber and remediation of waters ...

  17. Disturbed Copper Bioavailability in Alzheimer's Disease

    PubMed Central

    Kaden, Daniela; Bush, Ashley I.; Danzeisen, Ruth; Bayer, Thomas A.; Multhaup, Gerd

    2011-01-01

    Recent data from in vitro, animal, and human studies have shed new light on the positive roles of copper in many aspects of AD. Copper promotes the non-amyloidogenic processing of APP and thereby lowers the A? production in cell culture systems, and it increases lifetime and decreases soluble amyloid production in APP transgenic mice. In a clinical trial with Alzheimer patients, the decline of A? levels in CSF, which is a diagnostic marker, is diminished in the verum group (8?mg copper/day), indicating a beneficial effect of the copper treatment. These observations are in line with the benefit of treatment with compounds aimed at normalizing metal levels in the brain, such as PBT2. The data reviewed here demonstrate that there is an apparent disturbance in metal homeostasis in AD. More research is urgently needed to understand how this disturbance can be addressed therapeutically. PMID:22145082

  18. Purity test for copper-plating solutions

    NASA Technical Reports Server (NTRS)

    Mansfeld, F. B.

    1977-01-01

    Electrode configuration can be used to measure extent of impurities in acid-copper plating solution. It can be inserted into any plating tank and will show whether bath is clean or contaminated, within fifteen minutes.

  19. Electroless Copper Deposition: A Sustainable Approach

    NASA Astrophysics Data System (ADS)

    Kutnahorsky, Marika Renee

    A sustainable electroless copper coating process was developed for plating automotive fasteners shaped from AISI 9255 low carbon, high silicon steel. The objective was to minimize the ionic and organic species present in each step of the plating process. A sulfuric acid solution inhibited with quinine was defined to clean the steel prior to plating. The corrosivity of the solution was examined through electrochemical and weight loss measurements to evaluate the efficiency of the cleaning process at high temperatures and high acid concentrations. An electroless copper coating process was then developed using a simple copper sulfate chemistry inhibited with quinine to extend the possible operating window. Finally, benzotriazole was evaluated as a possible anti-oxidant coating. Accelerated thioacetamide corrosion tests were used to evaluate the corrosion inhibition of benzotriazole on copper coatings.

  20. Characterization of copper nanopowders after natural aging

    NASA Astrophysics Data System (ADS)

    Amelkovich, Yu A.; Nazarenko, O. B.; Sechin, A. I.; Visakh, P. M.

    2015-04-01

    Copper nanopowders after storage under natural conditions can oxidize and change their properties. In this work, the phase composition, morphology and thermal properties of copper nanopowders after natural aging of 10 years were studied. The copper nanopowders were produced by the method of electrical explosion of wires in different gaseous ambient: argon and carbon dioxide. The nanopowders were characterized by X-ray diffraction, thermal analysis, scanning electron microscopy, Fourier transform infrared spectroscopy. The content of copper oxides phases was found to be increased in comparison with freshly synthesized powders. This transformation results in the change of the thermal characteristics of the nanopowders. The effect of the synthesis conditions on the composition and thermal characteristics was shown.

  1. Characterizations of severely deformed and annealed copper 

    E-print Network

    Haouaoui, Mohammed

    2001-01-01

    The objectives of this study were to characterize severely plastically deformed and recrystallized oxygen free high conductivity copper, to determine texture transformation potential of Equal Channel Angular Extrusion (ECAE) and to investigate...

  2. Copper Sulphate as an Aquatic Herbicide

    Microsoft Academic Search

    Hamid Sharif El Din

    1954-01-01

    DURING the course of an experiment in the use of copper sulphate against bilharzia snail hosts in the season 1951-52, it was noted that the water-weed vegetation appeared to be affected by the treatment.

  3. Characterizations of severely deformed and annealed copper

    E-print Network

    Haouaoui, Mohammed

    2001-01-01

    The objectives of this study were to characterize severely plastically deformed and recrystallized oxygen free high conductivity copper, to determine texture transformation potential of Equal Channel Angular Extrusion (ECAE) and to investigate...

  4. Thickness Induced Buckling of bcc Copper Films

    SciTech Connect

    Ocko, B.M.; Weinert, M. [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)] [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States); Robinson, I.K. [Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States)] [Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States); Randler, R.J.; Kolb, D.M. [Department of Electrochemistry, University of Ulm, D-89069 Ulm (Germany)] [Department of Electrochemistry, University of Ulm, D-89069 Ulm (Germany)

    1999-07-01

    Copper films electrodeposited on Au(100) develop a buckling instability after the 11th layer leading to stripes with a 60{endash}75thinspthinsp{Angstrom} period. Analysis of the x-ray diffraction data shows that the entire copper film restructures by forming regions which are locally orthorhombic in a spatially modulated pattern. This distortion is supported by first-principles calculations. {copyright} {ital 1999} {ital The American Physical Society }

  5. Copper metallization for ULSL and beyond

    Microsoft Academic Search

    Shyam P. Murarka; Steven W. Hymes

    1995-01-01

    The investigation of copper for use as an interconnection metal in the ultra large-scale integration (ULSI) era of silicon integrated circuits has accelerated in the past several years. The obvious advantages for using copper to replace currently used Al are related to its lower resistivity (1.7 ??-cm vs. 2.7 ??-cm for Al) and its higher electromigration resistance (several orders of

  6. Copper Deficiency in Calves in Northcentral Manitoba

    PubMed Central

    Smart, M. E.; Gudmundson, J.; Brockman, R. P.; Cymbaluk, N.; Doige, C.

    1980-01-01

    Four seven month old Simmental calves were examined because of unthriftiness, a persistent cough, stiffness and lameness. The calves had gastrointestinal and pulmonary parasitism. Analysis of the blood copper levels of these calves and of cows and calves on the farm indicated a generalized deficiency. Only the calves affected with parasitism showed signs of clinical copper deficiency. ImagesFigure 1.Figure 2.Figure 3.Figure 4. PMID:7260830

  7. Defect of nanocrystalline copper and silver

    Microsoft Academic Search

    Zhikun Zhang; Zuolin Cui; Chuncheng Hao; Lifeng Dong; Zhaoguo Meng; Liyan Yu

    1998-01-01

    Nanoscale copper and silver were synthesized by the H2+Ar arc plasma method. During the synthesis, hydrogen molecules were dissociated into hydrogen atoms and stored in the particles.\\u000a At the same time, nanometer copper and silver particles were prepared by the inert gas condensation method whose power is\\u000a about identical with the hydrogen arc plasma method. Various specimens were annealed respectively

  8. Inherited copper toxicosis in Bedlington terriers.

    PubMed

    Robertson, H M; Studdert, V P; Reuter, R E

    1983-08-01

    Chronic hepatitis and increased hepatic copper concentrations, from 1,600 to 6,361 micrograms/g dry tissue were found in 4 related, Australian-bred Bedlington terriers. Two dogs were asymptomatic and 2 were clinically ill with signs referable to liver dysfunction. Two dogs were treated with d-penicillamine. After one year there was no improvement in the histopathological liver changes in either dog or significant lowering of hepatic copper level in one dog. PMID:6639527

  9. Biosorption of copper by water hyacinth roots

    Microsoft Academic Search

    K. S. Low; C. K. Lee; C. H. Tai

    1994-01-01

    Biomass of non?living dried water hyacinth roots, Eichhornia crassipes, showed high sorption for copper from aqueous solutions. Maximum sorption was 20.90 mg Cu\\/g as determined from Langmuir isotherm. Several factors affecting sorption were investigated. They include effect of pH, initial concentrations, presence of chelators and other metals. The feasibility of removing copper from electroplating waste using this material in a

  10. Micro brands manufacturing by copper vapor laser

    NASA Astrophysics Data System (ADS)

    Nikontchouk, Mikhail; Polyakov, Igor V.; Gorny, Sergey

    2001-10-01

    The manuscript presents the results of research of different processes of micro brands (identification marks) manufacturing. Two methods are taken into consideration, namely, the projection method and the method based on making brand by deep laser marking. These manufacturing methods are compared in terms of their accuracy, manufacturing flexibility and efficiency. There are a lot of micro brand manufacturing processes and one of them is laser deep marking. In this paper we consider brand manufacturing by Copper vapor lasers and compare it with well-known Nd:YAG laser. A copper vapor laser has a diffraction-limited divergence, a short pulse, and a high repetition rate. These properties enable an efficient evaporation of any material with a very small heat affected zone and with a minimal amount of the melted material. In the projection method a copper vapor laser cuts a mask of 0.15 mm copper foil. The mask image being projected to a material surface is five times less than the original mask. A pulse solid-state laser illuminating the mask evaporates the exposed material. An impact tool for brand stamping is made of steel by precision deep (0.5 mm) marking using a copper vapor laser. A laser beam 10 mm in diameter is deflected by electromechanical scanners and evaporates material layer by layer at the raster movement. Copper vapor laser marking makes possible the direct manufacturing of brands on gold surfaces at 0.5 mm depth with 10 mm accuracy as well.

  11. Regulation of copper absorption by copper availability in the Caco-2 cell intestinal model.

    PubMed

    Zerounian, Nora R; Redekosky, Carmen; Malpe, Rashmi; Linder, Maria C

    2003-05-01

    Relatively little is known about the individual steps in intestinal copper absorption and whether or how they may be regulated. Polarized Caco-2 cell monolayers with tight junctions offer an already tested model in which to study intestinal metal transport. This model was used to examine potential effects of cellular copper availability on copper absorption. Uptake and transport were determined on application of (64)Cu(II) to the brush border. In the range of 0.2-2 micro M, uptake was dose dependent and was approximately 20% of dose/90 min. Overall transport of (64)Cu across the basolateral surface was approximately 0.3%. When cellular copper levels were depleted 40% by 18-h pretreatment with the specific copper chelator triethylenetetraamine, uptake and overall transport were markedly increased, going to 80 and 65% of dose, respectively. Cellular retention of (64)Cu fell fourfold, from 6 to 1.5%. Depletion of copper with the chelator was rapid and preceded initial changes in uptake and overall transport by 4 h. A lesser depletion of cellular copper (13%) failed to enhance copper uptake but doubled the rate of overall transport, as measured with (64)Cu and by atomic absorption. As previously reported, preexposure of the cells to excess copper (10 micro M, 18 h) also enhanced copper uptake ( approximately 3-fold). In contrast, ascorbate (10-1,000 micro M) failed to significantly alter uptake and transport of 1 micro M (64)Cu. Our findings are consistent with the concepts that, in the low physiological range, copper availability alters the absorption capacity of the intestine to support whole body homeostasis and that basolateral transport is more sensitively regulated than uptake. PMID:12540371

  12. The effect of copper-amended fertiliser and copper oxide wire particles on the copper status of farmed red deer (Cervus elaphus) and their progeny

    Microsoft Academic Search

    ND Grace; PR Wilson; AK Quinn

    2005-01-01

    AIM: To determine changes in serum and liver copper concentrations in postnatal, weaner, yearling, and mature deer after grazing pasture topdressed with copper (Cu) at two rates of application of copper sulphate (CuSO4.5H2O), and following oral administration of copper oxide (CuO) wire particles to some of the deer.METHODS: In mid-March 2000 (Year 1), 1.1-ha paddocks (two\\/treatment) of ryegrass\\/white clover pasture

  13. Method for providing uranium with a protective copper coating

    DOEpatents

    Waldrop, Forrest B. (Powell, TN); Jones, Edward (Knoxville, TN)

    1981-01-01

    The present invention is directed to a method for providing uranium metal with a protective coating of copper. Uranium metal is subjected to a conventional cleaning operation wherein oxides and other surface contaminants are removed, followed by etching and pickling operations. The copper coating is provided by first electrodepositing a thin and relatively porous flash layer of copper on the uranium in a copper cyanide bath. The resulting copper-layered article is then heated in an air or inert atmosphere to volatilize and drive off the volatile material underlying the copper flash layer. After the heating step an adherent and essentially non-porous layer of copper is electro-deposited on the flash layer of copper to provide an adherent, multi-layer copper coating which is essentially impervious to corrosion by most gases.

  14. Putting copper into action: copper-impregnated products with potent biocidal activities.

    PubMed

    Borkow, Gadi; Gabbay, Jeffrey

    2004-11-01

    Copper ions, either alone or in copper complexes, have been used for centuries to disinfect liquids, solids, and human tissue. Today copper is used as a water purifier, algaecide, fungicide, nematocide, molluscicide, and antibacterial and antifouling agent. Copper also displays potent antiviral activity. We hypothesized that introducing copper into clothing, bedding, and other articles would provide them with biocidal properties. A durable platform technology has been developed that introduces copper into cotton fibers, latex, and other polymeric materials. This study demonstrates the broad-spectrum antimicrobial (antibacterial, antiviral, antifungal) and antimite activities of copper-impregnated fibers and polyester products. This technology enabled the production of antiviral gloves and filters (which deactivate HIV-1 and other viruses), antibacterial self-sterilizing fabrics (which kill antibiotic-resistant bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci), antifungal socks (which alleviate symptoms of athlete's foot), and anti-dust mite mattress covers (which reduce mite-related allergies). These products did not have skin-sensitizing properties, as determined by guine pig maximization and rabbit skin irritation tests. Our study demonstrates the potential use of copper in new applications. These applications address medical issues of the greatest importance, such as viral transmissions; nosocomial, or healthcare-associated, infections; and the spread of antibiotic-resistant bacteria. PMID:15345689

  15. The Effect of Copper Bearing Particles Liberation on Copper Recovery from Smelter Slag by Flotation

    Microsoft Academic Search

    Zoran M. Stirbanovic; Zoran S. Markovic

    2011-01-01

    In this paper we have presented the results of our study. We have investigated the impact of liberation of copper bearing particles on recovery of copper in the flotation process. Tests have shown that grinding of material highly impacts the recovery rate in the flotation process. Results of flotation of smelter slag samples with different contents of grain size fraction

  16. Sulfidation treatment of copper-containing plating sludge towards copper resource recovery.

    PubMed

    Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

    2006-11-01

    The present study is concerned with the sulfidation treatment of copper-containing plating sludge towards copper resource recovery by flotation of copper sulfide from treated sludge. The sulfidation treatment was carried out by contacting simulated or real copper plating sludge with Na(2)S solution for a period of 5 min to 24 h. The initial molar ratio of S(2-) to Cu(2+) (S(2-) to Me(2+) in the case of real sludge) was adjusted to 1.00, 1.25 or 1.50, while the solid to liquid ratio was set at 1:50. As a result, it was found that copper compounds were converted to various copper sulfides within the first 5 min. In the case of simulated copper sludge, CuS was identified as the main sulfidation product at the molar ratio of S(2-) to Cu(2+) of 1.00, while Cu(7)S(4) (Roxbyite) was mainly found at the molar ratios of S(2-) to Cu(2+) of 1.50 and 1.25. Based on the measurements of oxidation-reduction potential, the formation of either CuS or Cu(7)S(4) at different S(2-) to Cu(2+) molar ratios was attributed to the changes in the oxidation-reduction potential. By contrast, in the case of sulfidation treatment of real copper sludge, CuS was predominantly formed, irrespective of S(2-) to Me(2+) molar ratio. PMID:16806690

  17. Copper intake and health threat by consuming seafood from copper-contaminated coastal environments in Taiwan

    SciTech Connect

    Han, B.C. (Taipei Medical Coll. (Taiwan, Province of China). School of Public Health); Jeng, W.L.; Hung, T.C. (National Taiwan Univ., Taipei (Taiwan, Province of China). Inst. of Oceanography); Jeng, M.S. (Academia Sinica, Taipei (Taiwan, Province of China). Inst. of Zoology)

    1994-05-01

    The purpose of this paper is to describe the impact of copper pollution on the main aquaculture coast of Taiwan and the potential risk from eating the green oysters cultured along the polluted coast. The data show that the highest average concentration of copper in oysters was observed in the Erhjin Chi estuary from 1986 to 1990. The copper concentration in both the seawater and the sediment collected along the Erhjin Chi estuary was also the highest in all sampling locations. Copper concentration in oysters collected from Erhjin Chi, Hsiangshan, and Anping from 1988 to 1990 was, respectively, 61, 29, and 22 times higher than that of 10 years ago. The potential frisk from consuming oysters is relatively higher than that of other seafoods due the high bioaccumulation of oysters. The oysters in the Erhjin Chi estuary had an average concentration of copper of 3,075 [+-] 826 [mu]g/g during the past three years (1988--1990). The average copper intake from oysters for an adult with 70 kg body weight was 12.6 mg/d. The estimate indicated that the average copper intake from the oysters for female individuals is 14 times more than that of international limits. Based on the average value, long-term intake of copper through consumption of oysters cultured along the Erhjin Chi estuary be critical, especially for some high-risk groups.

  18. Independent Evolution of Heavy Metal-Associated Domains in Copper Chaperones and Copper-Transporting ATPases

    E-print Network

    Jordan, King

    Independent Evolution of Heavy Metal-Associated Domains in Copper Chaperones and Copper and structure to the Cu- binding heavy metal-associated (HMA) domains of Cu- transporting ATPases (Cu to the Cu-binding heavy metal-associated (HMA) domains of Cu-transporting ATPases (Cu- ATPases) whose genes

  19. Copper Recycling in the United States in 2004

    USGS Publications Warehouse

    Goonan, Thomas G.

    2009-01-01

    As one of a series of reports that describe the recycling of metal commodities in the United States, this report discusses the flow of copper from production through distribution and use, with particular emphasis on the recycling of industrial scrap (new scrap1) and used products (old scrap) in the year 2004. This materials flow study includes a description of copper supply and demand for the United States to illustrate the extent of copper recycling and to identify recycling trends. Understanding how materials flow from a source through disposition can aid in improving the management of natural resource delivery systems. In 2004, the U.S. refined copper supply was 2.53 million metric tons (Mt) of refined unalloyed copper. With adjustment for refined copper exports of 127,000 metric tons (t) of copper, the net U.S. refined copper supply was 2.14 Mt of copper. With this net supply and a consumer inventory decrease of 9,000 t of refined copper, 2.42 Mt of refined copper was consumed by U.S. semifabricators (brass mills, wire rod mills, ingot makers, and foundries and others) in 2004. In addition to the 2.42 Mt of refined copper consumed in 2004, U.S. copper semifabricators consumed 853,000 t of copper contained in recycled scrap. Furthermore, 61,000 t of copper contained in scrap was consumed by noncopper alloy makers, for example, steelmakers and aluminum alloy makers. Old scrap recycling efficiency for copper was estimated to be 43 percent of theoretical old scrap supply, the recycling rate for copper was 30 percent of apparent supply, and the new-scrap-to-old-scrap ratio for U.S. copper product production was 3.2 (76:24).

  20. Vitrification of copper flotation waste.

    PubMed

    Karamanov, Alexander; Aloisi, Mirko; Pelino, Mario

    2007-02-01

    The vitrification of an hazardous iron-rich waste (W), arising from slag flotation of copper production, was studied. Two glasses, containing 30wt% W were melted for 30min at 1400 degrees C. The first batch, labeled WSZ, was obtained by mixing W, blast furnace slag (S) and zeolite tuff (Z), whereas the second, labeled WG, was prepared by mixing W, glass cullet (G), sand and limestone. The glass frits showed high chemical durability, measured by the TCLP test. The crystallization of the glasses was evaluated by DTA. The crystal phases formed were identified by XRD resulting to be pyroxene and wollastonite solid solutions, magnetite and hematite. The morphology of the glass-ceramics was observed by optical and scanning electron microscopy. WSZ composition showed a high rate of bulk crystallization and resulted to be suitable for producing glass-ceramics by a short crystallization heat-treatment. WG composition showed a low crystallization rate and good sinterability; glass-ceramics were obtained by sinter-crystallization of the glass frit. PMID:17064848

  1. Activity of arsenic in copper

    NASA Astrophysics Data System (ADS)

    Lynch, D. C.

    1980-12-01

    Values have been reported in the literature for the Henrian activity coefficient for arsenic in molten copper ranging from 1.45 × 10-4 to 5 × 10-7 at temperatures between 1273 and 1573 K. In this study, that data was reexamined and was found to be in closer agreement than originally reported. The Henrian activity coefficient was found to range from 2.2 × 10-3 at 1273 K to 5.6 × 10-3 at 1373 K. The experimental data indicate that at 0.21 < NAs < 0.30 the activity coefficient ?As can be determined from the following equations: log ?As = -5.58 N{Cu/2} + 1.65 (T = 1273 K) log ?as = -6.22 NCu/2 + 2.25 (T = 1373 K) This study also examined the extent of the disassociation of tetratomic arsenic vapor as As, As2 and As3. The results of the analysis indicate that As2 is the predominant species when arsenic vapor, equilibrated with metallic arsenic at temperatures below 873 K, is heated to temperatures above 1273 K.

  2. Optical phonons in nanostructured thin films composed by zincblende zinc selenide quantum dots in strong size-quantization regime: Competition between phonon confinement and strain-related effects

    SciTech Connect

    Pejova, Biljana, E-mail: biljana@pmf.ukim.mk

    2014-05-01

    Raman scattering in combination with optical spectroscopy and structural studies by X-ray diffraction was employed to investigate the phonon confinement and strain-induced effects in 3D assemblies of variable-size zincblende ZnSe quantum dots close packed in thin film form. Nanostructured thin films were synthesized by colloidal chemical approach, while tuning of the nanocrystal size was enabled by post-deposition thermal annealing treatment. In-depth insights into the factors governing the observed trends of the position and half-width of the 1LO band as a function of the average QD size were gained. The overall shifts in the position of 1LO band were found to result from an intricate compromise between the influence of phonon confinement and lattice strain-induced effects. Both contributions were quantitatively and exactly modeled. Accurate assignments of the bands due to surface optical (SO) modes as well as of the theoretically forbidden transverse optical (TO) modes were provided, on the basis of reliable physical models (such as the dielectric continuum model of Ruppin and Englman). The size-dependence of the ratio of intensities of the TO and LO modes was studied and discussed as well. Relaxation time characterizing the phonon decay processes in as-deposited samples was found to be approximately 0.38 ps, while upon post-deposition annealing already at 200 °C it increases to about 0.50 ps. Both of these values are, however, significantly smaller than those characteristic for a macrocrystalline ZnSe sample. - Graphical abstract: Optical phonons in nanostructured thin films composed by zincblende zinc selenide quantum dots in strong size-quantization regime: competition between phonon confinement and strain-related effects. - Highlights: • Phonon confinement vs. strain-induced effects in ZnSe 3D QD assemblies were studied. • Shifts of the 1LO band result from an intricate compromise between the two effects. • SO and theoretically forbidden TO modes were accurately assigned. • Phonon relaxation time in as-deposited and annealed samples is 0.38 ps and 0.50 ps. • Both values are significantly smaller than in macrocrystalline ZnSe sample.

  3. The amyloid precursor protein of Alzheimer's disease in the reduction of copper(II) to copper(I)

    PubMed

    Multhaup, G; Schlicksupp, A; Hesse, L; Beher, D; Ruppert, T; Masters, C L; Beyreuther, K

    1996-03-01

    The transition metal ion copper(II) has a critical role in chronic neurologic diseases. The amyloid precursor protein (APP) of Alzheimer's disease or a synthetic peptide representing its copper-binding site reduced bound copper(II) to copper(I). This copper ion-mediated redox reaction led to disulfide bond formation in APP, which indicated that free sulfhydryl groups of APP were involved. Neither superoxide nor hydrogen peroxide had an effect on the kinetics of copper(II) reduction. The reduction of copper(II) to copper(I) by APP involves an electron-transfer reaction and could enhance the production of hydroxyl radicals, which could then attack nearby sites. Thus, copper-mediated toxicity may contribute to neurodegeneration in Alzheimer's disease. PMID:8596911

  4. Comparative study on the preparation of conductive copper pastes with copper nanoparticles prepared by electron beam irradiation and chemical reduction

    NASA Astrophysics Data System (ADS)

    Pham, Long Quoc; Sohn, Jong Hwa; Park, Ji Hyun; Kang, Hyun Suk; Lee, Byung Cheol; Kang, Young Soo

    2011-05-01

    Copper nanoparticles with narrow size distribution of 5-7 nm were synthesized by using electron beam irradiation. The copper nanoparticles were stable in ambient air for two months. TGA showed that the copper nanoparticles prepared by using electron beam irradiation have the higher wt% of pure copper metal compared with the one prepared by chemical reduction using hydrazine hydrate(N 2H 4· xH 2O). The conductive copper paste with copper nanoparticles prepared by electron beam irradiation showed higher conductivity than the paste with copper nanoparticles prepared by chemical reduction with N 2H 4 due to small size, less amount of surfactants on the surface and higher stability against the oxidation in ambient condition. The highest conductivity of copper paste was determined as 170 S cm -1 at 90 wt% of copper nanoparticles in the paste.

  5. Hereditary copper toxicosis in West Highland white terriers.

    PubMed

    Thornburg, L P; Shaw, D; Dolan, M; Raisbeck, M; Crawford, S; Dennis, G L; Olwin, D B

    1986-03-01

    Histologic, histochemical and atomic absorption studies on liver tissue from 71 West Highland white terriers are reported. Twenty-seven dogs had histologically normal liver and copper concentration comparable to mongrel control dogs. Forty-four dogs had hepatic copper concentrations up to 22 times the mean copper concentration found in clinically normal mongrel dogs. Hepatitis, hepatic necrosis and cirrhosis were associated with the increased copper concentration in some dogs. Matings between dogs with high liver copper concentration produced pups with high liver concentration. The copper storage defect is inherited. PMID:3962081

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

    NASA Astrophysics Data System (ADS)

    Nazim, Muhammad

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

  7. Mechanism of copper transport from plasma to hepatocytes

    SciTech Connect

    Ettinger, M.J.; Darwish, H.M.; Schmitt, R.C.

    1986-11-01

    The effects of plasma components on the kinetics of copper transport by rat hepatocytes were examined in an attempt to determine how copper is mobilized from plasma for uptake by the liver. Specific protein-facilitated transport was indicated by saturation kinetics, competition by related substrates, and similar kinetic parameters for uptake and efflux. For copper uptake, K/sub m/ = 11 +/- 0.6 ..mu..M and V/sub max/ = 2.7 +/- 0.6 nmol Cu/(min x mg protein). Zinc is a competitive inhibitor of copper uptake, and copper competes for zinc uptake. Copper efflux from preloaded cells is biphasic. The kinetic parameters for the initial rapid phase are similar to the parameters for uptake. Copper transport by hepatocytes is strictly passive. A variety of metabolic inhibitors have no effect on uptake and initial rates are solely dependent on extracellular-intracellular concentration gradients. Albumin markedly inhibits copper intake by a substrate removal mechanism, and histidine facilitates albumin-inhibited copper uptake. The active species that delivers copper to hepatocytes under conditions of excess albumin and excess histidine is the His/sub 2/Cu complex. Experiments with (/sup 3/H)His/sub 2/ /sup 64/Cu showed that the transported species is free ionic copper. The kinetic parameters of copper transport by hepatocytes isolated from the brindled mouse model of Menkes' disease are normal. However, these cells show a decreased capacity to accumulate copper on prolonged incubation. An intracellular metabolic defect seems to be involved.

  8. Hypertension in rats deficient in copper

    SciTech Connect

    Klevay, L.M.

    1986-03-01

    Male weanling rats were matched into two groups of equal mean weight (48 g), were fed a diet low in copper and zinc and were supplemented with a drinking solution with 10..mu..gZn and 2/sup +/gCu per ml until they grew to approximately 300 g. Systolic blood pressure (mmHg) was measured without anesthesia with an Electro-Sphygmomanometer and pneumatic pulse transducer; no significant difference between groups was found (0 > 0.05). Then copper was omitted from the solution of the group with lower blood pressure in each of two experiments. Plasma cholesterol (mg/dl) was measured by fluorometry and blood pressure was measured again 53 to 86 days later; mean (SE), n = 14, 15. Hypercholesterolemia verified deficiency. Hypotension in copper deficient rats in experiments of others probably was the result of cardiac defects induced in weanling animals. Hypertension joins hypercholesterolemia, hyperuricemia, glucose intolerance and abnormal electrocardiograms as a stigma of copper deficiency. Copper deficiency is the only nutritional insult that induces all of these characteristics useful in predicting risk of ischemic heart disease.

  9. Sol-gel-derived percolative copper film

    SciTech Connect

    Szu Sungping [Department of Physics, National Chung-Hsing University, Taichung 402, Taiwan (China)], E-mail: spszu@phys.nchu.edu.tw; Cheng, C.-L. [Department of Physics, National Chung-Hsing University, Taichung 402, Taiwan (China)

    2008-10-02

    Cu-SiO{sub 2} films were prepared by the sol-gel method. Two-dimensional fractal copper films were formed after the films were thermally treated in reducing atmosphere. dc resistances of the films decrease 12 orders of magnitude as the content of copper increases from 70 to 80 mol%. During the resistance measurement under argon atmosphere, samples showed a sharp increase or decrease of resistance at a transition temperature which is ascribed to the oxidation of Cu into CuO. The oxidation was also observed in the in situ high temperature X-ray diffraction under vacuum condition. The evolution of the morphology of the films was studied by scanning electron microscopy. As the content of copper increases, the forms of copper particles change from discrete to aggregate then to interconnecting. The coverage coefficients of the copper range from 23 to 55% and the fractal dimensions range from 1.65 to 1.77. The percolation thresholds for the coverage coefficient and the fractal dimension are about 33% and 1.71, respectively, which corresponds to the sample containing 72.5 mol% of Cu.

  10. Variations in the intralobular distribution of copper in the livers of copper-loaded rats in relation to the pathogenesis of copper storage diseases.

    PubMed

    Fuentealba, I; Haywood, S; Trafford, J

    1989-01-01

    There are differences in the hepatic intralobular distribution of copper in copper storage related diseases which may be of pathogenetic significance. Male rats fed a high copper diet (1500 ppm) for 16 weeks were killed at intervals in an attempt to compare copper distribution in their livers with those in human, canine and ovine copper toxicosis. Copper was found to accumulate almost exclusively in the periportal and mid-zones of the rat liver lobules and was associated with progressive pathological changes which included focal and periportal degeneration and necrosis. This pattern of copper distribution contrasts markedly with the centrilobular retention reported in familial canine copper toxicosis and chronic copper poisoning in sheep which suggests that, in these conditions, a secretory deficiency may be less important than a metabolic zonal defect of intracellular copper metabolism. The pathological changes observed in copper-loaded rats have a different micro-anatomical localization from those in dogs and sheep, but show similarities to the early changes reported in the latter species and indicate the possibility of a similar cellular lesion. PMID:2918104

  11. Metallic copper corrosion rates, moisture content, and growth medium influence survival of copper ion-resistant bacteria.

    PubMed

    Elguindi, Jutta; Moffitt, Stuart; Hasman, Henrik; Andrade, Cassandra; Raghavan, Srini; Rensing, Christopher

    2011-03-01

    The rapid killing of various bacteria in contact with metallic copper is thought to be influenced by the influx of copper ions into the cells, but the exact mechanism is not fully understood. This study showed that the kinetics of contact killing of copper surfaces depended greatly on the amount of moisture present, copper content of alloys, type of medium used, and type of bacteria. We examined antibiotic- and copper ion-resistant strains of Escherichia coli and Enterococcus faecium isolated from pig farms following the use of copper sulfate as feed supplement. The results showed rapid killing of both copper ion-resistant E. coli and E. faecium strains when samples in rich medium were spread in a thin, moist layer on copper alloys with 85% or greater copper content. E. coli strains were rapidly killed under dry conditions, while E. faecium strains were less affected. Electroplated copper surface corrosion rates were determined from electrochemical polarization tests using the Stern-Geary method and revealed decreased corrosion rates with benzotriazole and thermal oxide coating. Copper ion-resistant E. coli and E. faecium cells suspended in 0.8% NaCl showed prolonged survival rates on electroplated copper surfaces with benzotriazole coating and thermal oxide coating compared to surfaces without anti-corrosion treatment. Control of surface corrosion affected the level of copper ion influx into bacterial cells, which contributed directly to bacterial killing. PMID:21085951

  12. Metallic copper corrosion rates, moisture content, and growth medium influence survival of copper-ion resistant bacteria

    PubMed Central

    Elguindi, Jutta; Moffitt, Stuart; Hasman, Henrik; Andrade, Cassandra; Raghavan, Srini; Rensing, Christopher

    2013-01-01

    The rapid killing of various bacteria in contact with metallic copper is thought to be influenced by influx of copper ions into the cells but the exact mechanism is not fully understood. This study showed that the kinetics of contact-killing of copper surfaces depended greatly on the amount of moisture present, copper content of alloys, type of medium used, and type of bacteria. We examined antibiotic- and copper-ion resistant strains of Escherichia coli and Enterococcus faecium isolated from pig farms following the use of copper sulfate as feed supplement. The results showed rapid killing of both copper-ion resistant E. coli and E. faecium strains when samples in rich medium were spread in a thin, moist layer on copper alloys with 85% or greater copper content. E. coli strains were rapidly killed under dry conditions while E. faecium strains were less affected. Electroplated copper surface corrosion rates were determined from electro-chemical polarization tests using the Stern-Geary method and revealed decreased corrosion rates with benzotriazole and thermal oxide coating. Copper-ion resistant E. coli and E. faecium cells suspended in 0.8% NaCl showed prolonged survival rates on electroplated copper surfaces with benzotriazole coating and thermal oxide coating compared to surfaces without anti-corrosion treatment. Control of surface corrosion affected the level of copper ion influx into bacterial cells which contributed directly to bacterial killing. PMID:21085951

  13. Effect of copper impurity on polycrystalline silicon solar cells

    NASA Technical Reports Server (NTRS)

    Daud, T.; Koliwad, K. M.

    1978-01-01

    The presence of copper impurity, up to 10 to the 15th atoms/cc, in single crystal silicon has been shown to have no deleterious effect on the p-n junction solar cell performance. However, in polycrystalline silicon, copper atoms tend to migrate to the defect sites because of the structural sensitive properties of copper. This study was undertaken to investigate the influence of this behavior of copper impurity on the performance of p-n junction solar cells fabricated from structurally imperfect silicon. Two sets of polycrystalline silicon substrates containing copper were examined. In one set of samples, copper was incorporated during growth, whereas in the other, copper was diffused. Solar cells were fabricated on both the sets of substrates by a standard process. Dark and light I-V and spectral response characteristics of the cells were measured and compared with copper-free polycrystalline silicon solar cells. The results and the model are discussed.

  14. Pathogenic adaptations to host-derived antibacterial copper

    PubMed Central

    Chaturvedi, Kaveri S.; Henderson, Jeffrey P.

    2014-01-01

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

  15. New canine models of copper toxicosis: diagnosis, treatment, and genetics.

    PubMed

    Fieten, Hille; Penning, Louis C; Leegwater, Peter A J; Rothuizen, Jan

    2014-05-01

    The One Health principle recognizes that human health, animal health, and environmental health are inextricably linked. An excellent example is the study of naturally occurring copper toxicosis in dogs to help understand human disorders of copper metabolism. Besides the Bedlington terrier, where copper toxicosis is caused by a mutation in the COMMD1 gene, more complex hereditary forms of copper-associated hepatitis were recognized recently in other dog breeds. The Labrador retriever is one such breed, where an interplay between genetic susceptibility and exposure to copper lead to clinical copper toxicosis. Purebred dog populations are ideal for gene mapping studies, and because genes involved in copper metabolism are highly conserved across species, newly identified gene mutations in the dog may help unravel the genetic complexity of different human forms of copper toxicosis. Furthermore, increasing knowledge with respect to diagnosis and treatment strategies will benefit both species. PMID:24758744

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

    SciTech Connect

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

    1986-03-05

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

  17. Preparation of polyamine-functionalized copper specific adsorbents for selective adsorption of copper.

    PubMed

    Yu, Zhiyuan; Wu, Ren'an; Wu, Minghuo; Zhao, Liang; Li, Ruibin; Zou, Hanfa

    2010-07-01

    The level of serum free copper is greatly elevated in Wilson's disease. For patients with acute Wilson's disease, liver transplantation is the only lifesaving treatment. Plasma exchange or albumin dialysis is often used as a bridge to liver transplantation to maintain a stable clinical status for patients. Hemoperfusion is another effective therapy in removing toxins from the plasma. However, hemoperfusion has not been reported to remove copper due to lack of copper specific adsorbent. In this work, copper chelating agents, triethylenetetramine and tetraethylenepentamine, were covalently immobilized onto macroporous poly(glycidyl methacrylate-co-trimethylolpropane trimethacrylate) microspheres to prepare copper specific adsorbents. The resulting adsorbents demonstrated good adsorption capacities of 63.44 and 58.48 mg/g, respectively, for Cu2+ ion. Additionally, with the interference of other metal ions such as Fe2+, Mg2+, Zn2+ and Ca2+, the prepared copper adsorbents still demonstrated good specificity toward Cu2+ ion. These results indicate that the adsorbents are promising adsorbents in hemoperfusion therapy for selective removal of copper for patients with severe Wilson's disease. PMID:20381321

  18. Cratering on thermosonic copper wire ball bonding

    NASA Astrophysics Data System (ADS)

    Wei, Tan Chee; Daud, Abdul Razak

    2002-06-01

    Copper wire bonding offers several mechanical and electrical advantages as well as cost saving compared to its gold wire predecessor. Despite these benefits, silicon cratering, which completes the fracture and removal of bond pad underlayers, has been a major hurdle to overcome in copper wire bonding. Copper wire is harder than gold, and thus needs greater ultrasonic power and bond force to bond it onto metal pads such as aluminum. This paper reports a study on the influence of wire materials, bond pad hardness, and bonding-machine parameters (i.e., ultrasonic power and bond force) on silicon cratering phenomenon. Ultrasonic power and z-axis bond force were identified as the most critical bonding machine parameters in silicon cratering defects. A combination of greater bond force and lower ultrasonic power avoids silicon cratering and gives the desired effects. Results also show that a harder bond pad provides relatively good protection from silicon cratering.

  19. Growth Of Single Crystalline Copper Nanowhiskers

    NASA Astrophysics Data System (ADS)

    Kolb, Matthias; Richter, Gunther

    2010-11-01

    Nanowhiskers are defect free single crystals with high aspect ratios and as result exhibit superior physical, e.g. mechanical properties. This paper sheds light on the kinetics of copper nanowhisker growth and thickening. Whisker growth was provoked by covering silicon wafers with a thin carbon film and subsequently coating them with copper by molecular beam epitaxy. The whiskers grown were examined by scanning electron microscopy and the length and diameter were measured as a function of the amount of copper deposited. The experiments show that nanowhisker growth follows Ruth and Hirth's growth model. A fit of the model parameters to the acquired data shows that adsorption of atoms on the substrate and on the whisker surface, with subsequent surface diffusion to the whisker tip, delivers by far the greatest portion of material for whisker growth. Additionally, the experiments demonstrate that the crystallographic orientation of the substrate surface greatly influences the growth rate in the early stage of whisker growth.

  20. Copper Electrodeposition for 3D Integration

    E-print Network

    Beica, Rozalia; Ritzdorf, Tom

    2008-01-01

    Two dimensional (2D) integration has been the traditional approach for IC integration. Due to increasing demands for providing electronic devices with superior performance and functionality in more efficient and compact packages, has driven the semiconductor industry to develop more advanced packaging technologies. Three-dimensional (3D) approaches address both miniaturization and integration required for advanced and portable electronic products. Vertical integration proved to be essential in achieving a greater integration flexibility of disparate technologies, reason for which a general trend of transition from 2D to 3D integration is currently being observed in the industry. 3D chip integration using through silicon via (TSV) copper is considered one of the most advanced technologies among all different types of 3D packaging technologies. Copper electrodeposition is one of technologies that enable the formation of TSV structures. Because of its well-known application for copper damascene, it was believed ...

  1. Graphene-protected copper and silver plasmonics.

    PubMed

    Kravets, V G; Jalil, R; Kim, Y-J; Ansell, D; Aznakayeva, D E; Thackray, B; Britnell, L; Belle, B D; Withers, F; Radko, I P; Han, Z; Bozhevolnyi, S I; Novoselov, K S; Geim, A K; Grigorenko, A N

    2014-01-01

    Plasmonics has established itself as a branch of physics which promises to revolutionize data processing, improve photovoltaics, and increase sensitivity of bio-detection. A widespread use of plasmonic devices is notably hindered by high losses and the absence of stable and inexpensive metal films suitable for plasmonic applications. To this end, there has been a continuous search for alternative plasmonic materials that are also compatible with complementary metal oxide semiconductor technology. Here we show that copper and silver protected by graphene are viable candidates. Copper films covered with one to a few graphene layers show excellent plasmonic characteristics. They can be used to fabricate plasmonic devices and survive for at least a year, even in wet and corroding conditions. As a proof of concept, we use the graphene-protected copper to demonstrate dielectric loaded plasmonic waveguides and test sensitivity of surface plasmon resonances. Our results are likely to initiate wide use of graphene-protected plasmonics. PMID:24980150

  2. Comparative effects of dissolved copper and copper oxide nanoparticle exposure to the sea anemone, Exaiptasia pallida.

    PubMed

    Siddiqui, Samreen; Goddard, Russell H; Bielmyer-Fraser, Gretchen K

    2015-03-01

    Increasing use of metal oxide nanoparticles (NP) by various industries has resulted in substantial output of these NP into aquatic systems. At elevated concentrations, NP may interact with and potentially affect aquatic organisms. Environmental implications of increased NP use are largely unknown, particularly in marine systems. This research investigated and compared the effects of copper oxide (CuO) NP and dissolved copper, as copper chloride (CuCl2), on the sea anemone, Exaiptasia pallida. Sea anemones were collected over 21 days and tissue copper accumulation and activities of the enzymes: catalase, glutathione peroxidase, glutathione reductase, and carbonic anhydrase were quantified. The size and shape of CuO NP were observed using a ecanning electron microscope (SEM) and the presence of copper was confirmed by using Oxford energy dispersive spectroscopy systems (EDS/EDX). E. pallida accumulated copper in their tissues in a concentration- and time-dependent manner, with the animals exposed to CuCl2 accumulating higher tissue copper burdens than those exposed to CuO NP. As a consequence of increased copper exposure, as CuO NP or CuCl2, anemones increased activities of all of the antioxidant enzymes measured to some degree, and decreased the activity of carbonic anhydrase. Anemones exposed to CuO NP generally had higher anti-oxidant enzyme activities than those exposed to the same concentrations of CuCl2. This study is useful in discerning differences between CuO NP and dissolved copper exposure and the findings have implications for exposure of aquatic organisms to NP in the environment. PMID:25661886

  3. The copper chaperone Atox1 in canine copper toxicosis in Bedlington terriers.

    PubMed

    Nanji, M S; Cox, D W

    1999-11-15

    Copper toxicosis, resulting in liver disease, commonly occurs in Bedlington terriers. This recessively inherited disorder, similar in many respects to Wilson disease, is of particular interest because the canine Atp7b gene, homologous to ATP7B defective in Wilson disease, is not responsible for canine copper toxicosis as has been expected. Atox1, a copper chaperone delivering copper to Atp7b, therefore became a potential candidate. We cloned canine Atox1, which shows conserved motifs of the copper-binding domain (MTCXXC) and of the lysine-rich region (KTGK), and showed 88, 80, and 41% amino acid sequence identity with the orthologous mouse, human, and yeast proteins. No gross deletions of Atox1 could be identified in the affected Bedlington terriers by Southern blot analysis of genomic DNA. The canine Atox1 gene spans about 4 kb, with a 204-bp open reading frame cDNA contained within two exons. Sequence analysis of the coding regions, including intron/exon boundaries, showed no mutations in Atox1 from genomic DNA of an affected dog. We have also identified an apparently nontranscribed canine Atox1 pseudogene, with 12 sequence changes and no intron. Mapping of Atox1 and a marker closely linked to the canine copper toxicosis locus indicated lack of synteny. Atox1 is therefore excluded as a candidate gene for canine copper toxicosis, indicating that some other unidentified gene must be responsible for this copper storage disease in dogs and also suggesting the possibility of a similar gene responsible for a copper storage disease in humans. PMID:10585777

  4. Copper recovery from chalcopyrite concentrates by the BRISA process

    Microsoft Academic Search

    R Romero; A Mazuelos; I Palencia; F Carranza

    2003-01-01

    The technical viability of the BRISA process (Biolixiviación Rápida Indirecta con Separación de Acciones: Fast Indirect Bioleaching with Actions Separation) for the copper recovery from chalcopyrite concentrates has been proved. Two copper concentrates (with a copper content of 8.9 and 9.9 wt.%) with chalcopyrite as the dominant copper mineral have been leached with ferric sulphate at 12 g\\/L of ferric

  5. SELECTIVE DISSOLUTION OF COPPER OXALATE USING SUPPORTED LIQUID MEMBRANES

    Microsoft Academic Search

    Damir Kralj; Gerdi R. M. Breembroek; Geert Jan Witkamp; Gerda M. van Rosmalen; Ljerka Bre?evi?

    1996-01-01

    A supported liquid membrane has been used to dissolve selectively copper oxalate from a suspension of copper, calcium and cadmium oxalate, which have low, similar solubilities. 2-Hydroxy-5-nonyl-acetophenone oxime (HX) dissolved in kerosene was used as a carrier for copper transport from the suspension to the stripping solution. A mathematical model of the copper permeation is presented. The model takes into

  6. Pesticidal Copper (I) Oxide: Environmental Fate and Aquatic Toxicity

    Microsoft Academic Search

    Lina Kiaune; Nan Singhasemanon

    \\u000a Besides being a naturally occurring element and an essential micronutrient, copper is used as a pesticide, but at generally\\u000a higher concentrations. Copper, unlike organic pesticides, does not degrade, but rather enters a complex biogeochemical cycle.\\u000a In the water column, copper can exist bound to both organic and inorganic species and as free or hydrated copper ions. Water\\u000a column chemistry affects

  7. Copper removal using electrosterically stabilized nanocrystalline cellulose.

    PubMed

    Sheikhi, Amir; Safari, Salman; Yang, Han; van de Ven, Theo G M

    2015-06-01

    Removal of heavy metal ions such as copper using an efficient and low-cost method with low ecological footprint is a critical process in wastewater treatment, which can be achieved in a liquid phase using nanoadsorbents such as inorganic nanoparticles. Recently, attention has turned toward developing sustainable and environmentally friendly nanoadsorbents to remove heavy metal ions from aqueous media. Electrosterically stabilized nanocrystalline cellulose (ENCC), which can be prepared from wood fibers through periodate/chlorite oxidation, has been shown to have a high charge content and colloidal stability. Here, we show that ENCC scavenges copper ions by different mechanisms depending on the ion concentration. When the Cu(II) concentration is low (C0 ? 200 ppm), agglomerates of starlike ENCC particles appear, which are broken into individual starlike entities by shear and Brownian motion, as evidenced by photometric dispersion analysis, dynamic light scattering, and transmission electron microscopy. On the other hand, at higher copper concentrations, the aggregate morphology changes from starlike to raftlike, which is probably due to the collapse of protruding dicarboxylic cellulose (DCC) chains and ENCC charge neutralization by copper adsorption. Such raftlike structures result from head-to-head and lateral aggregation of neutralized ENCCs as confirmed by transmission electron microscopy. As opposed to starlike aggregates, the raftlike structures grow gradually and are prone to sedimentation at copper concentrations C0 ? 500 ppm, which eliminates a costly separation step in wastewater treatment processes. Moreover, a copper removal capacity of ?185 mg g(-1) was achieved thanks to the highly charged DCC polyanions protruding from ENCC. These properties along with the biorenewability make ENCC a promising candidate for wastewater treatment, in which fast, facile, and low-cost removal of heavy metal ions is desired most. PMID:25950624

  8. Studies on copper alloys containing chromium on the copper side phase diagram

    NASA Technical Reports Server (NTRS)

    Doi, T.

    1984-01-01

    Specimens were prepared from vacuum melted alloys of high purity vacuum melted copper and electrolytic chromium. The liquidus and eutectic point were determined by thermal analysis. The eutectic temperature is 1974.8 F and its composition is 1.28 wt% of chromium. The determination of solid solubility of chromium in copper was made by microscopic observation and electrical resistivity measurement. The solubility of chromium in solid copper is 0.6 wt% at 1050 F, 0.4 wt% at 1000 F, 0.25 wt% at 950 F, 0.17 wt% at 900 F, and 0.30 wt% at 840 F.

  9. Bioavailability of copper proteinate and copper carbonate relative to copper sulfate in cattle.

    PubMed

    Ward, J D; Spears, J W; Kegley, E B

    1996-01-01

    Two experiments were conducted to determine the relative bioavailabilities of Cu proteinate, CuCO3, and CuSO4. In Experiment 1, 30 heifers that had been depleted of Cu were us 1. Treatments were control, Cu proteinate A, Cu proteinate B, CuCO3, and CuSO4. Sources provided 50 mg of Cu/d. Supplementation increased plasma Cu by d 21, but there were no differences among the sources. Heifers supplemented with Cu had greater liver Cu concentrations on d 21 than did controls. Heifers receiving CuCO3 had lower liver Cu concentrations than the other heifers. In Experiment 2, 40 heifers were fed diets containing 0.15% of added S and 5 mg of added Mo/kg of DM. Treatments were control, CuSO4, CuCO3, and Cu proteinate A. All sources provided 5 mg of added Cu/kg of DM. Controls and heifers supplemented with CuSO4 had declining plasma Cu concentrations. Supplementation with CuCO3 or Cu proteinate A maintained plasma Cu concentrations. Heifers supplemented with Cu proteinate A had smaller decreases in liver Cu concentrations than did heifers supplemented with other Cu sources. In the absence of high Mo, Cu proteinates were similar in bioavailability to CuSO4. In the presence of high Mo, Cu proteinate A appeared to have a greater bioavailability than CuSO4. Copper carbonate increased or maintained plasma Cu concentrations but was not stored in the liver efficiently. PMID:8675775

  10. Electron density measurements in copper vapor lasers

    NASA Astrophysics Data System (ADS)

    Petrash, Gueorgii G.

    2000-04-01

    A critical overview of the results of electron density measurements in copper vapor lasers is presented. There are considerable contradictions between the results of measurements made by different methods especially between the results concerning temporal behavior of electron density between excitation pulses. Possible reasons of these contradictions are discussed. The method of electron density measurement based on atomic hydrogen Balmer lines broadening is considered in greater detail. Possible nature of the Balmer lines emission under the conditions of copper vapor laser operation and processes of the lines broadening are discussed.

  11. Low-toxicity copper corrosion inhibitors

    SciTech Connect

    Stupnisek-Lisac, E.; Bozic, A.L. [Univ. of Zagreb (Croatia). Faculty of Chemical Engineering and Technology; Cafuk, I. [PLIVA--Pharmaceutic Industry, Zagreb (Croatia). Lab. for Ecological Engineering

    1998-09-01

    The efficiency of various imidazole derivatives as corrosion inhibitors for copper i hydrochloric and sulfuric acids (HCl and H{sub 2}SO{sub 4}) was investigated. Electrochemical measurements showed the organic compounds investigated have fairly good inhibiting properties, except for 4-methyl-5-imidazole-carbaldehyde in HCl. Protecting properties of most imidazole derivatives were close to those of commercial inhibitors for copper. Evaluation of the toxicity of the water solutions on the biological system for treatment of waste water--as measured in regard to chemical oxygen demand (COD), aerobic, and anaerobic toxicity--showed the tested inhibitors have relatively low toxicity.

  12. 6,000 years of copper smelting : Center for the Study of Copper Smelting in Ancient Societies

    E-print Network

    Steinberg, Marc J. (Marc Jonathan), 1969-

    2000-01-01

    In 1959 professor of archeology Beno Rothenberg began investigating the production of copper in the Sinai desert and Aravah region of southern Israel. He discovered over 650 previously unknown ancient copper mining and ...

  13. Process for producing copper barrier type, nuclear fuel cladding

    Microsoft Academic Search

    T. Ishikawa; K. Murakami; M. Wajima

    1982-01-01

    A copper barrier type, nuclear fuel cladding is produced by forming an oxide layer on the inner wall surface of a tube of zirconium or zirconium alloy and then applying electroless copper plating to the oxide layer with a solution containing at least a copper salt, a complexing agent, a reducing agent, and 2,2'dipyridyl, or further together with polyalkylene glycol

  14. Tantalum-copper alloy and method for making

    DOEpatents

    Schmidt, Frederick A. (Ames, IA); Verhoeven, John D. (Ames, IA); Gibson, Edwin D. (Ames, IA)

    1984-11-06

    A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

  15. Tantalum-copper alloy and method for making

    DOEpatents

    Schmidt, F.A.; Verhoeven, J.D.; Gibson, E.D.

    1983-06-01

    A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

  16. ENVIRONMENTAL FATE AND ECOLOGICAL IMPACT OF COPPER HYDROXIDE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper, applied in the form of copper hydroxide, is a widely used fungicide/bactericide for control of plant diseases. Copper has been shown to have adverse effects on aquatic organisms including a reduction in macroinvertebrate survival and structural and functional effects on fish nervous systems....

  17. Bioavailable copper modulates oxidative phosphorylation and growth of tumors

    PubMed Central

    Ishida, Seiko; Andreux, Pénélope; Poitry-Yamate, Carole; Auwerx, Johan; Hanahan, Douglas

    2013-01-01

    Copper is an essential trace element, the imbalances of which are associated with various pathological conditions, including cancer, albeit via largely undefined molecular and cellular mechanisms. Here we provide evidence that levels of bioavailable copper modulate tumor growth. Chronic exposure to elevated levels of copper in drinking water, corresponding to the maximum allowed in public water supplies, stimulated proliferation of cancer cells and de novo pancreatic tumor growth in mice. Conversely, reducing systemic copper levels with a chelating drug, clinically used to treat copper disorders, impaired both. Under such copper limitation, tumors displayed decreased activity of the copper-binding mitochondrial enzyme cytochrome c oxidase and reduced ATP levels, despite enhanced glycolysis, which was not accompanied by increased invasiveness of tumors. The antiproliferative effect of copper chelation was enhanced when combined with inhibitors of glycolysis. Interestingly, larger tumors contained less copper than smaller tumors and exhibited comparatively lower activity of cytochrome c oxidase and increased glucose uptake. These results establish copper as a tumor promoter and reveal that varying levels of copper serves to regulate oxidative phosphorylation in rapidly proliferating cancer cells inside solid tumors. Thus, activation of glycolysis in tumors may in part reflect insufficient copper bioavailability in the tumor microenvironment. PMID:24218578

  18. Orientation dependence of thermal conductivity in copper-graphene composites

    Microsoft Academic Search

    K. Jagannadham

    2011-01-01

    Copper and graphene multilayer films were deposited on a copper substrate. The surface of the multilayer film was covered with another film of copper by electrochemical deposition. An electrically insulating film of polymer followed by films of silicon and yttria-stabilized zirconia were deposited to isolate the sample electrically from a gold heater line deposited on the top. The three-omega method

  19. LONG-TERM IMPACTS OF ORTHOPHOSPHATE TREATMENT ON COPPER

    EPA Science Inventory

    Laboratory, pilot, and field data collected support the theoretical "cupric hydroxide" copper solubility model. For the short time frames inherent in laboratory and pilot studies of copper solubility and in initial field monitoring for the LCR from Tier 1 soldered copper sites, c...

  20. Copper deficiency in a herd of captive muskoxen.

    PubMed Central

    Blakley, B R; Tedesco, S C; Flood, P F

    1998-01-01

    At necropsy, a mature muskox cow was found to have exceedingly low serum and liver copper concentrations of 4.8 = mumol/L and 0.02 mmol/kg, respectively. Serum copper levels were also low in remaining members of the herd but returned to normal after parenteral treatment with calcium copper edetate. PMID:9592616