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

    DOEpatents

    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).

  2. Precursors for formation of copper selenide, indium selenide, copper indium diselenide, and/or copper indium gallium diselenide films

    DOEpatents

    Curtis, Calvin J; Miedaner, Alexander; Van Hest, Maikel; Ginley, David S

    2014-11-04

    Liquid-based precursors for formation of Copper Selenide, Indium Selenide, Copper Indium Diselenide, and/or copper Indium Galium Diselenide include 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. These liquid-based precursors can be deposited in liquid form onto substrates and treated by rapid thermal processing to form crystalline copper selenide and indium selenide films.

  3. Oxidation Mechanism of Copper Selenide

    NASA Astrophysics Data System (ADS)

    Taskinen, Pekka; Patana, Sonja; Kobylin, Petri; Latostenmaa, Petri

    2014-09-01

    The oxidation mechanism of copper selenide was investigated at deselenization temperatures of copper refining anode slimes. The isothermal roasting of synthetic, massive copper selenide in flowing oxygen and oxygen - 20% sulfur dioxide mixtures at 450-550 °C indicate that in both atmospheres the mass of Cu2Se increases as a function of time, due to formation of copper selenite as an intermediate product. Copper selenide oxidises to copper oxides without formation of thick copper selenite scales, and a significant fraction of selenium is vaporized as SeO2(g). The oxidation product scales on Cu2Se are porous which allows transport of atmospheric oxygen to the reaction zone and selenium dioxide vapor to the surrounding gas. Predominance area diagrams of the copper-selenium system, constructed for selenium roasting conditions, indicate that the stable phase of copper in a selenium roaster gas with SO2 is the sulfate CuSO4. The cuprous oxide formed in decomposition of Cu2Se is further sulfated to CuSO4.

  4. 40 CFR 721.10391 - Copper gallium indium selenide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Copper gallium indium selenide. 721.10391 Section 721...Substances § 721.10391 Copper gallium indium selenide. (a) Chemical substance...substance identified as copper gallium indium selenide (PMN P-10-424; CAS...

  5. 40 CFR 721.10391 - Copper gallium indium selenide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Copper gallium indium selenide. 721.10391 Section 721...Substances § 721.10391 Copper gallium indium selenide. (a) Chemical substance...substance identified as copper gallium indium selenide (PMN P-10-424; CAS...

  6. 40 CFR 721.10391 - Copper gallium indium selenide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Copper gallium indium selenide. 721.10391 Section 721...Substances § 721.10391 Copper gallium indium selenide. (a) Chemical substance...substance identified as copper gallium indium selenide (PMN P-10-424; CAS...

  7. Copper selenide nanocrystals for photothermal therapy.

    PubMed

    Hessel, Colin M; Pattani, Varun P; Rasch, Michael; Panthani, Matthew G; Koo, Bonil; Tunnell, James W; Korgel, Brian A

    2011-06-01

    Ligand-stabilized copper selenide (Cu(2-x)Se) nanocrystals, approximately 16 nm in diameter, were synthesized by a colloidal hot injection method and coated with amphiphilic polymer. The nanocrystals readily disperse in water and exhibit strong near-infrared (NIR) optical absorption with a high molar extinction coefficient of 7.7 × 10(7) cm(-1) M(-1) at 980 nm. When excited with 800 nm light, the Cu(2-x)Se nanocrystals produce significant photothermal heating with a photothermal transduction efficiency of 22%, comparable to nanorods and nanoshells of gold (Au). In vitro photothermal heating of Cu(2-x)Se nanocrystals in the presence of human colorectal cancer cell (HCT-116) led to cell destruction after 5 min of laser irradiation at 33 W/cm(2), demonstrating the viabilitiy of Cu(2-x)Se nanocrystals for photothermal therapy applications. PMID:21553924

  8. Electrodeposition of copper selenide films from acidic bath and their properties

    NASA Astrophysics Data System (ADS)

    Mane, Rajaram S.; Shaikh, Arif V.; Joo, Oh-Shim; Han, Sung-Hwan; Pathan, Habib M.

    2012-06-01

    Copper selenide thin films are successfully deposited using electrodeposition method by combining copper sulfate and sodiumseleno sulfate precursors at room temperature in acidic bath. The chemical composition was a key factor in preparing high-quality uniform and smooth thin films of the copper selenide. We present indium-tin-oxide as a substrate for depositing copper selenide films which usually exists as copper (I) selenide or copper (II) selenide. Obtained brownish films of copper selenide are examined for their structural, morphological, compositional and optical properties by means of X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and optical absorption measurement techniques, respectively for the structural, morphological and optical analysis.

  9. Aqueous preparation of surfactant-free copper selenide nanowires.

    PubMed

    Chen, Xinqi; Li, Zhen; Yang, Jianping; Sun, Qiao; Dou, Shixue

    2015-03-15

    Uniform surfactant-free copper selenide (Cu2-xSe) nanowires were prepared via an aqueous route. The effects of reaction parameters such as Cu/Se precursor ratio, Se/NaOH ratio, and reaction time on the formation of nanowires were comprehensively investigated. The results show that Cu2-xSe nanowires were formed through the assembling of CuSe nanoplates, accompanied by their self-redox reactions. The resultant Cu2-xSe nanowires were explored as a potential thermoelectric candidate in comparison with commercial copper selenide powder. Both synthetic and commercial samples have a similar performance and their figures of merit are 0.29 and 0.38 at 750K, respectively. PMID:25527088

  10. 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

  11. 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.

  12. 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.

  13. Chemical synthesis of p-type nanocrystalline copper selenide thin films for heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Ambade, Swapnil B.; Mane, R. S.; Kale, S. S.; Sonawane, S. H.; Shaikh, Arif V.; Han, Sung-Hwan

    2006-12-01

    Nanocrystalline thin films of copper selenide have been grown on glass and tin doped-indium oxide substrates using chemical method. At ambient temperature, golden films have been synthesized and annealed at 200 °C for 1 h and were examined for their structural, surface morphological and optical properties by means of X-ray diffraction (XRD), scanning electron microscopy and UV-vis spectrophotometry techniques, respectively. Cu 2- xSe phase was confirmed by XRD pattern and spherical grains of 30 ± 4 - 40 ± 4 nm in size aggregated over about 130 ± 10 nm islands were seen by SEM images. Effect of annealing on crystallinity improvement, band edge shift and photoelectrochemical performance (under 80 mW/cm 2 light intensity and in lithium iodide electrolyte) has been studied and reported. Observed p-type electrical conductivity in copper selenide thin films make it a suitable candidate for heterojunction solar cells.

  14. Metal ions to control the morphology of semiconductor nanoparticles: copper selenide nanocubes.

    PubMed

    Li, Wenhua; Zamani, Reza; Ibáñez, Maria; Cadavid, Doris; Shavel, Alexey; Morante, Joan Ramon; Arbiol, Jordi; Cabot, Andreu

    2013-03-27

    Morphology is a key parameter in the design of novel nanocrystals and nanomaterials with controlled functional properties. Here, we demonstrate the potential of foreign metal ions to tune the morphology of colloidal semiconductor nanoparticles. We illustrate the underlying mechanism by preparing copper selenide nanocubes in the presence of Al ions. We further characterize the plasmonic properties of the obtained nanocrystals and demonstrate their potential as a platform to produce cubic nanoparticles with different composition by cation exchange. PMID:23470030

  15. 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.

  16. Specific features of photoluminescence properties of copper-doped cadmium selenide quantum dots

    SciTech Connect

    Tselikov, G. I., E-mail: gleb@vega.phys.msu.ru [Moscow State University, Faculty of Physics (Russian Federation); Dorofeev, S. G.; Tananaev, P. N. [Moscow State University, Faculty of Chemistry (Russian Federation); Timoshenko, V. Yu. [Moscow State University, Faculty of Physics (Russian Federation)

    2011-09-15

    The effect of doping with copper on the photoluminescence properties of cadmium selenide quantum dots 4 nm in dimension is studied. The quenching of the excitonic photoluminescence band related to the quantum dots and the appearance of an impurity photoluminescence band in the near-infrared region are observed after doping of the quantum dots with copper. It is established that, on doping of the quantum dots, the photoluminescence kinetics undergoes substantial changes. The photoluminescence kinetics of the undoped quantum dots is adequately described by a sum of exponential relaxation relations, whereas the photoluminescence kinetics experimentally observed in the region of the impurity band of the copper-doped samples follows stretched exponential decay, with the average lifetimes 0.3-0.6 {mu}s at the photon energies in the range of 1.47-1.82 eV. The experimentally observed changes in the photoluminescence properties are attributed to transformation of radiative centers in the quantum dots when doped with copper atoms.

  17. Synthesis and characterization of wurtzite-phase copper tin selenide nanocrystals.

    PubMed

    Norako, Michelle E; Greaney, Matthew J; Brutchey, Richard L

    2012-01-11

    A new wurtzite phase of copper tin selenide (CTSe) was discovered, and the resulting nanocrystals were synthesized via a facile solution-phase method. The wurtzite CTSe nanocrystals were synthesized with dodecylamine and 1-dodecanethiol as coordinating solvents and di-tert-butyl diselenide ((t)Bu(2)Se(2)) as the selenium source. Specific reaction control (i.e., a combination of 1-dodecanethiol with (t)Bu(2)Se(2)) was proven to be critical in order to obtain this new phase of CTSe, which was verified by powder X-ray diffraction and selected area electron diffraction. The wurtzite CTSe nanocrystals possess an optical and electrochemical band gap of 1.7 eV and display an electrochemical photoresponse indicative of a p-type semiconductor. PMID:22148639

  18. 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

  19. Highly efficient copper-zinc-tin-selenide (CZTSe) solar cells by electrodeposition.

    PubMed

    Jeon, Jong-Ok; Lee, Kee Doo; Seul Oh, Lee; Seo, Se-Won; Lee, Doh-Kwon; Kim, Honggon; Jeong, Jeung-hyun; Ko, Min Jae; Kim, BongSoo; Son, Hae Jung; Kim, Jin Young

    2014-04-01

    Highly efficient copper-zinc-tin-selenide (Cu2ZnSnSe4 ; CZTSe) thin-film solar cells are prepared via the electrodepostion technique. A metallic alloy precursor (CZT) film with a Cu-poor, Zn-rich composition is directly deposited from a single aqueous bath under a constant current, and the precursor film is converted to CZTSe by annealing under a Se atmosphere at temperatures ranging from 400 °C to 600 °C. The crystallization of CZTSe starts at 400 °C and is completed at 500 °C, while crystal growth continues at higher temperatures. Owing to compromises between enhanced crystallinity and poor physical properties, CZTSe thin films annealed at 550 °C exhibit the best and most-stable device performances, reaching up to 8.0 % active efficiency; among the highest efficiencies for CZTSe thin-film solar cells prepared by electrodeposition. Further analysis of the electronic properties and a comparison with another state-of-the-art device prepared from a hydrazine-based solution, suggests that the conversion efficiency can be further improved by optimizing parameters such as film thickness, antireflection coating, MoSe2 formation, and p-n junction properties. PMID:24692285

  20. Highly Luminescent, Size- and Shape-Tunable Copper Indium Selenide Based Colloidal Nanocrystals

    PubMed Central

    2013-01-01

    We report a simple, high-yield colloidal synthesis of copper indium selenide nanocrystals (CISe NCs) based on a silylamide-promoted approach. The silylamide anions increase the nucleation rate, which results in small-sized NCs exhibiting high luminescence and constant NC stoichiometry and crystal structure regardless of the NC size and shape. In particular, by systematically varying synthesis time and temperature, we show that the size of the CISe NCs can be precisely controlled to be between 2.7 and 7.9 nm with size distributions down to 9–10%. By introducing a specific concentration of silylamide-anions in the reaction mixture, the shape of CISe NCs can be preselected to be either spherical or tetrahedral. Optical properties of these CISe NCs span from the visible to near-infrared region with peak luminescence wavelengths of 700 to 1200 nm. The luminescence efficiency improves from 10 to 15% to record values of 50–60% by overcoating as-prepared CISe NCs with ZnSe or ZnS shells, highlighting their potential for applications such as biolabeling and solid state lighting. PMID:24748721

  1. Investigation of the ablation of zinc oxide thin films on copper-indium-selenide layers by ps laser pulses

    NASA Astrophysics Data System (ADS)

    Heise, Gerhard; Dickmann, Marcel; Domke, Matthias; Heiss, Andreas; Kuznicki, Thomas; Palm, Jörg; Richter, Isabel; Vogt, Helmut; Huber, Heinz P.

    2011-07-01

    The selective laser structuring of zinc oxide thin films, which serve as the transparent negative electrodes of copper-indium-selenide (CIS) thin film solar cells, is of great common interest as it can replace the mechanical scribing of the so-called pattern 3 (P3) process step for the monolithic serial interconnection of these cells. We present an investigation of the single-pulse ablation behavior of zinc oxide thin films on glass substrates and on CIS layers and of trench scribing with 10-ps laser pulses at 1064 nm and at 532 nm. We show that the ablation behavior strongly depends on the properties of the underling substrate and that the energy required to ablate a specific volume using induced laser processes (often referred to as `lift off') is considerably reduced compared to the direct ablation of zinc oxide. With laser powers below 2 W at a wavelength of 1064 nm process speeds of 6 m/s for the P3 process have been achieved.

  2. Thin-film copper indium gallium selenide solar cell based on low-temperature all-printing process.

    PubMed

    Singh, Manjeet; Jiu, Jinting; Sugahara, Tohru; Suganuma, Katsuaki

    2014-09-24

    In the solar cell field, development of simple, low-cost, and low-temperature fabrication processes has become an important trend for energy-saving and environmental issues. Copper indium gallium selenide (CIGS) solar cells have attracted much attention due to the high absorption coefficient, tunable band gap energy, and high efficiency. However, vacuum and high-temperature processing in fabrication of solar cells have limited the applications. There is a strong need to develop simple and scalable methods. In this work, a CIGS solar cell based on all printing steps and low-temperature annealing is developed. CIGS absorber thin film is deposited by using dodecylamine-stabilized CIGS nanoparticle ink followed by printing buffer layer. Silver nanowire (AgNW) ink and sol-gel-derived ZnO precursor solution are used to prepare a highly conductive window layer ZnO/[AgNW/ZnO] electrode with a printing method that achieves 16 ?/sq sheet resistance and 94% transparency. A CIGS solar cell based on all printing processes exhibits efficiency of 1.6% with open circuit voltage of 0.48 V, short circuit current density of 9.7 mA/cm(2), and fill factor of 0.34 for 200 nm thick CIGS film, fabricated under ambient conditions and annealed at 250 °C. PMID:25180569

  3. The development of 6.7% efficient copper zinc indium selenide devices from copper zinc indium sulfide nanocrystal inks

    NASA Astrophysics Data System (ADS)

    Graeser, Brian K.

    As solar cell absorber materials, alloys of CuIn(S,Se)2 and Zn(S,Se) provide an opportunity to reduce the usage of indium along with the ability to tune the band gap. Here we report successful synthesis of alloyed (CuInS2)0.5(ZnS)0.5 nanocrystals by a method that solely uses oleylamine as the liquid medium for synthesis. The reactive sintering of a thin film of these nanocrystals via selenization at 500 °C results in a uniform composition alloy (CuIn(S,Se)2)0.5(Zn(S,Se)) 0.5 layer with micron size grains. Due to the large amount of zinc in the film, the sintered grains exhibit the zinc blende structure instead of the usual chalcopyrite structure of CuIn(S,Se)2 films. The use of the selenide films as a p-type absorber layer has yielded solar cells with total area power conversion efficiencies as high as 6.7% (7.4% based on active area). These preliminary results are encouraging and indicate that with further optimization this class of materials has promise as the absorber layer in solar cells.

  4. Growth and Characterization of the p-type Semiconductors Tin Sulfide and Bismuth Copper Oxy Selenide

    NASA Astrophysics Data System (ADS)

    Francis, Jason

    BiCuOSe and SnS are layered, moderate band gap (epsilon G ? 1 eV) semiconductors that exhibit intrinsic p type conductivity. Doping of BiCuOSe with Ca results in a slight expansion of the lattice and an increase of the hole concentration from 10 18 cm--3 to greater than 1020 cm --3. The large carrier density in undoped films is the result of copper vacancies. Mobility is unaffected by doping, remaining constant at 1.5 cm2V--1s--1 in both undoped and doped films, because the Bi-O layers serve as the source of carriers, while transport occurs within the Cu-Se layers. Bi possesses a 6s2 lone pair that was expected to hybridize with the oxygen p states at the top of the valence band, resulting in high hole mobility as compared to similar materials such as LaCuOSe, which lack this lone pair. However, both LaCuOSe and BiCuOSe have similar hole mobility. X-ray absorption and emission spectroscopy, combined with density functional theory calculations, reveal that the Bi 6 s states contribute deep within the valence band, forming bonding and anti-bonding states with O 2p at 11 eV and 3 eV below the valence band maximum, respectively. Hence, the Bi lone pair does not contribute at the top of the valence band and does not enhance the hole mobility. The Bi 6p states contribute at the bottom of the conduction band, resulting in a smaller band gap for BiCuOSe than LaCuOSe (1 eV vs. 3 eV). SnS is a potential photovoltaic absorber composed of weakly coupled layers stacked along the long axis. This weak coupling results in the formation of strongly oriented films on amorphous substrates. The optical band gap is 1.2 eV, in agreement with GW calculations. Absorption reaches 105 cm--1 within 0.5 eV of the band gap. The p type conduction arises from energetically favorable tin vacancies. Variation of growth conditions yields carrier densities of 1014 -- 1016 cm--3 and hole mobility of 7 -- 15 cm2V--1s--1. SnS was alloyed with rocksalt CaS, which was predicted to form a rocksalt structure when the calcium content is increased past 18%. Films of Sn1--x CaxS with x from 0.4 to 0.9 adopt the rocksalt structure with a band gap of 1.1-1.3 eV, with absorption greater than 105 cm--1 within about 0.7 eV of the band gap. The lattice contracts as the calcium content of the films is increased, reaching 5.7 A when x = 0.93. Films are highly insulating, but Seebeck measurements do indicate p type conduction.

  5. 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

  6. Template free-solvothermaly synthesized copper selenide (CuSe, Cu 2- xSe, ?-Cu 2Se and Cu 2Se) hexagonal nanoplates from different precursors at low temperature

    NASA Astrophysics Data System (ADS)

    Kumar, Pushpendra; Singh, Kedar; Srivastava, O. N.

    2010-09-01

    Nonstoichiometric (Cu 2- xSe) and stoichiometric (CuSe, ?-Cu 2Se and Cu 2Se) copper selenide hexagonal nanoplates have been synthesized using different general and convenient copper sources, e.g. copper chloride, copper sulphate, copper nitrate, copper acetate, elemental copper with elemental selenium, friendly ethylene glycol and hydrazine hydrate in a defined amount of water at 100 °C within 12 h adopting the solvothermal method. Phase analysis, purity and morphology of the product have been well studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray diffraction (EDAX) techniques. The structural and compositional analysis revealed that the products were of pure phase with corresponding atomic ratios. SEM, TEM and HRTEM analyses revealed that the nanoplates were in the range 200-450 nm and the as-prepared products were uniform and highly crystallized. The nanoplates consisted of {0 0 1} facets of top-bottom surfaces and {1 1 0} facets of the other six side surfaces. This new approach encompasses many advantages over the conventional solvothermal method in terms of product quality (better morphology control with high yield) and reaction conditions (lower temperatures). Copper selenide hexagonal nanoplates obtained by the described method could be potential building blocks to construct functional devices and solar cell. This work may open up a new rationale on designing the solution synthesis of nanostructures for materials possessing similar intrinsic crystal symmetry. On the basis of the carefully controlled experiments mentioned herein, a plausible formation mechanism of the hexagonal nanoplates was suggested and discussed. To the best of our knowledge, this is the first report on nonstoichiometric (Cu 2- xSe) as well as stoichiometric (CuSe, ?-Cu 2Se and Cu 2Se) copper selenide hexagonal nanoplates with such full control of morphologies and phases by this method under mild conditions.

  7. 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.

  8. 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.

  9. Magnetometer uses bismuth-selenide

    NASA Technical Reports Server (NTRS)

    Woollman, J. A.; Spain, I. L.; Beale, H.

    1972-01-01

    Characteristics of bismuth-selenide magnetometer are described. Advantages of bismuth-selenide magnetometer over standard magnetometers are stressed. Thermal stability of bismuth-selenide magnetometer is analyzed. Linearity of output versus magnetic field over wide range of temperatures is reported.

  10. 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.

  11. Selenide retention by mackinawite.

    PubMed

    Finck, N; Dardenne, K; Bosbach, D; Geckeis, H

    2012-09-18

    The isotope (79)Se may be of great concern with regard to the safe disposal of nuclear wastes in deep geological repositories due to its long half-life and potential mobility in the geosphere. The Se mobility is controlled by the oxidation state: the oxidized species (Se(IV)) and (Se(VI)) are highly mobile, whereas the reduced species (Se(0) and Se(-II)) form low soluble solids. The mobility of this trace pollutant can be greatly reduced by interacting with the various barriers of the repository. Numerous studies report on the oxidized species retention by mineral phases, but only very scarce studies report on the selenide (Se(-II)) retention. In the present study, the selenide retention by coprecipitation with and by adsorption on mackinawite (FeS) was investigated. XRD and SEM analyses of the samples reveal no significant influence of Se on the mackinawite precipitate morphology and structure. Samples from coprecipitation and from adsorption are characterized at the molecular scale by a multi-edge X-ray absorption spectroscopy (XAS) investigation. In the coprecipitation experiment, all elements (S, Fe, and Se) are in a low ionic oxidation state and the EXAFS data strongly point to selenium located in a mackinawite-like sulfide environment. By contacting selenide ions with FeS in suspension, part of Se is located in an environment similar to that found in the coprecipitation experiment. The explanation is a dynamical dissolution-recrystallization mechanism of the highly reactive mackinawite. This is the first experimental study to report on selenide incorporation in iron monosulfide by a multi-edge XAS approach. PMID:22900520

  12. 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.

  13. 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.

  14. Hydrogen selenide treatment of electrolytes

    SciTech Connect

    Rasmussen, J. R.; Virkar, A. V.

    1985-01-29

    A method for lowering the activation energy of a polycrystalline ceramic electrolyte is disclosed. Polycrystalline ceramic electrolytes, such as beta-alumina, when contacted with hydrogen selenide exhibit a lower activation energy than untreated electrolytes.

  15. 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...

  16. Copper

    MedlinePLUS

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

  17. Low-Resistivity Zinc Selenide for Heterojunctions

    NASA Technical Reports Server (NTRS)

    Stirn, R. J.

    1986-01-01

    Magnetron reactive sputtering enables doping of this semiconductor. Proposed method of reactive sputtering combined with doping shows potential for yielding low-resistivity zinc selenide films. Zinc selenide attractive material for forming heterojunctions with other semiconductor compounds as zinc phosphide, cadmium telluride, and gallium arsenide. Semiconductor junctions promising for future optoelectronic devices, including solar cells and electroluminescent displays. Resistivities of zinc selenide layers deposited by evaporation or chemical vapor deposition too high to form practical heterojunctions.

  18. Crystal chemistry and solid lubricating properties of the monochalcogenides gallium selenide and tin selenide

    NASA Astrophysics Data System (ADS)

    Erdemir, Ali

    1994-07-01

    The interatomic array and bond structure in crystalline states of the monochalcogenides tin selenide and gallium selenide are described and correlated with their solid lubricating capacity. Friction tests assessing their solid lubricating performance were carried out on pin-on-disk machine. Specifically, large crystalline pieces of each inorganic solid were cut and cleaved into flat squares and subsequently rubbed against sapphire balls. In another case, fine powders of gallium selenide and tin selenide and tin selenide were manually fed into the sliding interfaces of 440C pins and 440C disks. For the specific test conditions explored, friction coefficients of the sapphirel gallium selenide and sapphire/tin selenide pairs were approximately 0.23 and approximately 0.35, respectively. The friction coefficients of 440C pin/440C disk test pairs with gallium selenide and tin selenide powders were approximately 0.22 and approximately 0.38, respectively. For comparison, a number of parallel friction tests were also performed with MoS2 powders and compacts, and the results of these tests are reported. The friction data, together with the crystal-chemical knowledge and electron microscopy evidence, supported the conclusion that the solid lubricating capabilities and lubrication mechanisms of these solids are closely related to their crystal chemistry and the nature of their interlayer bonding.

  19. 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.

  20. 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

  1. Alloyed copper chalcogenide nanoplatelets via partial cation exchange reactions.

    PubMed

    Lesnyak, Vladimir; George, Chandramohan; Genovese, Alessandro; Prato, Mirko; Casu, Alberto; Ayyappan, S; Scarpellini, Alice; Manna, Liberato

    2014-08-26

    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

  2. Study of filamentation threshold in zinc selenide.

    PubMed

    Durand, Magali; Houard, Aurélien; Lim, Khan; Durécu, Anne; Vasseur, Olivier; Richardson, Martin

    2014-03-10

    The possibility of creating filaments with laser wavelengths ranging from 800 nm to 2.4 µm was investigated using an OPA laser system. Zinc Selenide's (ZnSe) unique characteristics - small band gap E(gZnSe)=2.67eV and positive dispersion for this wavelength range - are well suited for filamentation study where multi-photon absorption can be achieved with two to six photons. PMID:24663922

  3. The stoichiometry of single nanoparticles of copper zinc tin selenide.

    PubMed

    Haas, Wernfried; Rath, Thomas; Pein, Andreas; Rattenberger, Johannes; Trimmel, Gregor; Hofer, Ferdinand

    2011-02-21

    Cu(2)ZnSnSe(4) nanoparticles have high potential to be used as ink for printable solar cells. Using transmission electron microscopy we show that these nanoparticles exhibit a broad range of chemical heterogeneity. These results are contrary to the interpretation of previous experimental work and will have considerable impact on the development of these nanoparticles. PMID:21184006

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

    PubMed

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

    2014-07-01

    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

  5. Synthesis and characterization of luminescent cadmium selenide/zinc selenide/zinc sulfide cholinomimetic quantum dots

    NASA Astrophysics Data System (ADS)

    Gégout, Claire; McAtee, Maria L.; Bennett, Nichole M.; Viranga Tillekeratne, L. M.; Kirchhoff, Jon R.

    2012-07-01

    Luminescent quantum dots conjugated with highly selective molecular recognition ligands are widely used for targeting and imaging biological structures. In this paper, water soluble cholinomimetic cadmium selenide (core), zinc selenide/zinc sulfide (shell) quantum dots were synthesized for targeting cholinergic sites. Cholinomimetic specificity was incorporated by conjugation of the quantum dots to an aminated analogue of hemicholinium-15, a well known competitive inhibitor of the high affinity choline uptake transporter. Detailed evaluation of the nanocrystal synthesis and characterization of the final product was conducted by 1H and 31P NMR, absorption and emission spectroscopy, as well as transmission electron microscopy.Luminescent quantum dots conjugated with highly selective molecular recognition ligands are widely used for targeting and imaging biological structures. In this paper, water soluble cholinomimetic cadmium selenide (core), zinc selenide/zinc sulfide (shell) quantum dots were synthesized for targeting cholinergic sites. Cholinomimetic specificity was incorporated by conjugation of the quantum dots to an aminated analogue of hemicholinium-15, a well known competitive inhibitor of the high affinity choline uptake transporter. Detailed evaluation of the nanocrystal synthesis and characterization of the final product was conducted by 1H and 31P NMR, absorption and emission spectroscopy, as well as transmission electron microscopy. Electronic supplementary information (ESI) available: NMR spectra supporting the synthesis of the HC-15 QDs are available. See DOI: 10.1039/c2nr30713h

  6. A new tin niobium selenide superconductor

    NASA Astrophysics Data System (ADS)

    Soreau-Leblanc, A.; Molin´, P.; Jumas, J. C.

    1997-08-01

    The new selenide SnNb 5Se 9 has been synthesized and characterized by density measurements, X-ray powder diffraction. The cell, determined by U-fit software, derives from that of NbSe 2; it presents a superstructure and an important disorder along the c axis, a single crystal study confirms these points. Mo¨ssbauer studies show three types of Sn atom. Magnetic properties show a superconducting behavior at 17.1 K with ?H c1/?T= 71G.K -1 and ?H c2/?T= 5kG.K -1.

  7. 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.

  8. [Optical constants determination of zinc selenide by inversing transmittance spectrogram].

    PubMed

    Li, Dong; Ai, Qing; Xia, Xin-Lin

    2013-04-01

    The transmittance models of single slab and two spliced slabs were built, and a new method to determine optical constants of materials was proposed based on inversing the transmittance spectrograms of single slab and two spliced slabs. The measurements of transmittance spectrogram of zinc selenide glass slabs with different thickness in the infrared wavelength range of 1.33-21 microm at normal incidence were investigated by Bruke V70 FTIR spectrometer. The optical constants of zinc selenide were achieved by the inverse methods. The results indicate that the optical constants of zinc selenide determined by the new inverse method are in good agreement with previous data sets. PMID:23841401

  9. Limiting pump intensity for sulfur-doped gallium selenide crystals

    NASA Astrophysics Data System (ADS)

    Guo, J.; Li, D.-J.; Xie, J.-J.; Zhang, L.-M.; Feng, Z.-S.; Andreev, Yu M.; Kokh, K. A.; Lanskii, G. V.; Potekaev, A. I.; Shaiduko, A. V.; Svetlichnyi, V. A.

    2014-05-01

    High optical quality undoped and sulfur-doped gallium selenide crystals were grown from melts by the modified vertical Bridgman method. Detailed study of the damage produced under femtosecond pulse exposure has shown that evaluation of the damage threshold by visual control is unfounded. Black matter spots produced on crystal surfaces do not noticeably decrease either its transparency or its frequency conversion efficiency as opposed to real damage identified as caked well-cohesive gallium structures. For the first time it was demonstrated that optimally sulfur-doped gallium selenide crystal possesses the highest resistivity to optical emission (about four times higher in comparison with undoped gallium?selenide).

  10. Precursor conversion kinetics and the nucleation of cadmium selenide nanocrystals.

    PubMed

    Owen, Jonathan S; Chan, Emory M; Liu, Haitao; Alivisatos, A Paul

    2010-12-29

    The kinetics of cadmium selenide (CdSe) nanocrystal formation was studied using UV-visible absorption spectroscopy integrated with an automated, high-throughput synthesis platform. Reaction of anhydrous cadmium octadecylphosphonate (Cd-ODPA) with alkylphosphine selenides (1, tri-n-octylphosphine selenide; 2, di-n-butylphenylphosphine selenide; 3, n-butyldiphenylphosphine selenide) in recrystallized tri-n-octylphosphine oxide was monitored by following the absorbance of CdSe at ? = 350 nm, where the extinction coefficient is independent of size, and the disappearance of the selenium precursor using {(1)H}(31)P NMR spectroscopy. Our results indicate that precursor conversion limits the rate of nanocrystal nucleation and growth. The initial precursor conversion rate (Q(o)) depends linearly on [1] (Q(o)(1) = 3.0-36 ?M/s) and decreases as the number of aryl groups bound to phosphorus increases (1 > 2 > 3). Changes to Q(o) influence the final number of nanocrystals and thus control particle size. Using similar methods, we show that changing [ODPA] has a negligible influence on precursor reactivity while increasing the growth rate of nuclei, thereby decreasing the final number of nanocrystals. These results are interpreted in light of a mechanism where the precursors react in an irreversible step that supplies the reaction medium with a solute form of the semiconductor. PMID:21128655

  11. Ex situ formation of metal selenide quantum dots using bacterially derived selenide precursors

    NASA Astrophysics Data System (ADS)

    Fellowes, J. W.; Pattrick, R. A. D.; Lloyd, J. R.; Charnock, J. M.; Coker, V. S.; Mosselmans, J. F. W.; Weng, T.-C.; Pearce, C. I.

    2013-04-01

    Luminescent quantum dots were synthesized using bacterially derived selenide (SeII-) as the precursor. Biogenic SeII- was produced by the reduction of SeIV by Veillonella atypica and compared directly against borohydride-reduced SeIV for the production of glutathione-stabilized CdSe and ?-mercaptoethanol-stabilized ZnSe nanoparticles by aqueous synthesis. Biological SeII- formed smaller, narrower size distributed QDs under the same conditions. The growth kinetics of biologically sourced CdSe phases were slower. The proteins isolated from filter sterilized biogenic SeII- included a methylmalonyl-CoA decarboxylase previously characterized in the closely related Veillonella parvula. XAS analysis of the glutathione-capped CdSe at the S K-edge suggested that sulfur from the glutathione was structurally incorporated within the CdSe. A novel synchrotron based XAS technique was also developed to follow the nucleation of biological and inorganic selenide phases, and showed that biogenic SeII- is more stable and more resistant to beam-induced oxidative damage than its inorganic counterpart. The bacterial production of quantum dot precursors offers an alternative, ‘green’ synthesis technique that negates the requirement of expensive, toxic chemicals and suggests a possible link to the exploitation of selenium contaminated waste streams.

  12. Ex Situ Formation of Metal Selenide Quantum Dots Using Bacterially Derived Selenide Precursors

    SciTech Connect

    Fellowes, Jonathan W.; Pattrick, Richard; Lloyd, Jon; Charnock, John M.; Coker, Victoria S.; Mosselmans, JFW; Weng, Tsu-Chien; Pearce, Carolyn I.

    2013-04-12

    Luminescent quantum dots were synthesized using bacterially derived selenide (SeII-) as the precursor. Biogenic SeII- was produced by the reduction of Se-IV by Veillonella atypica and compared directly against borohydride-reduced Se-IV for the production of glutathione-stabilized CdSe and beta-mercaptoethanol-stabilized ZnSe nanoparticles by aqueous synthesis. Biological SeII- formed smaller, narrower size distributed QDs under the same conditions. The growth kinetics of biologically sourced CdSe phases were slower. The proteins isolated from filter sterilized biogenic SeII- included a methylmalonyl-CoA decarboxylase previously characterized in the closely related Veillonella parvula. XAS analysis of the glutathione-capped CdSe at the S K-edge suggested that sulfur from the glutathione was structurally incorporated within the CdSe. A novel synchrotron based XAS technique was also developed to follow the nucleation of biological and inorganic selenide phases, and showed that biogenic SeII- is more stable and more resistant to beam-induced oxidative damage than its inorganic counterpart. The bacterial production of quantum dot precursors offers an alternative, 'green' synthesis technique that negates the requirement of expensive, toxic chemicals and suggests a possible link to the exploitation of selenium contaminated waste streams.

  13. 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

  14. Optical absorption in tin selenide thin films

    NASA Astrophysics Data System (ADS)

    Wahab, Y. B.; Hutagalung, S. D.; Sakrani, S. B.

    1998-02-01

    Tin selenide (SnSe) thin films have been prepared by encapsulated selenization technique. The Sn/Se stacked films were deposited by vacuum evaporation and annealed at 200 degrees Celsius for 3 hours to form a stoichiometric SnSe compound. Optical absorption measurements were made on the as- prepared sample using spectrophotometer in the range from UV to visible region (200 - 900 nm). The absorption coefficient, (alpha) was found to be greater than 105 cm-1 that suggested the occurrence of either indirect allowed or direct forbidden optical transition. A further investigations on the (ahv)1/2 and (ahv)2/3 plots against photon energy have been carried out and the resulting optical bandgap obtained from indirect allowed transitions were 0.95 eV for 40.5 nm sample and reduced to 0.79 eV for 125 nm sample thickness. In the case of direct forbidden transition, the energy gaps were between 1.20 - 1.08 nm. The results also showed that the band gap decreased with increasing sample thickness.

  15. Preparation and Characterization of Silver Selenide Thin Film

    NASA Astrophysics Data System (ADS)

    Chandrasekar, L. Bruno; Vijayalakshmi, R.; Rajeswari, B.; Chandramohan, R.; Arivazhagan, G.; Packiaseeli, S. Arulmozhi

    2014-09-01

    Silver selenide, a phase-changing chalcogenide material, is prepared using electro deposition method for various molarities. X-ray diffraction studies show the cubic lattice of the material. The micro-structural properties such as grain size, strain, dislocation density, and texture coefficient are examined. The lattice constant is calculated using Nelson-Relay function. Morphological studies are done and uniform distributions of grains are observed. High purities of thin films are confirmed by energy dispersive X-ray analysis. The band gap is calculated using UV-vis spectroscopy and photoluminescence technique, and hence, the Stokes's effect is observed in silver selenide thin films. It is the first time that the lattice constant and the Urbach energy for various molarities in the case of silver selenide thin films are reported.

  16. Preparation and Characterization of Silver Selenide Thin Film

    NASA Astrophysics Data System (ADS)

    Chandrasekar, L. Bruno; Vijayalakshmi, R.; Rajeswari, B.; Chandramohan, R.; Arivazhagan, G.; Packiaseeli, S. Arulmozhi

    2014-12-01

    Silver selenide, a phase-changing chalcogenide material, is prepared using electro deposition method for various molarities. X-ray diffraction studies show the cubic lattice of the material. The micro-structural properties such as grain size, strain, dislocation density, and texture coefficient are examined. The lattice constant is calculated using Nelson-Relay function. Morphological studies are done and uniform distributions of grains are observed. High purities of thin films are confirmed by energy dispersive X-ray analysis. The band gap is calculated using UV-vis spectroscopy and photoluminescence technique, and hence, the Stokes's effect is observed in silver selenide thin films. It is the first time that the lattice constant and the Urbach energy for various molarities in the case of silver selenide thin films are reported.

  17. Ovonic type switching in tin selenide thin films

    NASA Technical Reports Server (NTRS)

    Baxter, C. R.; Mclennan, W. D.

    1975-01-01

    Amorphous tin selenide thin films which possess Ovonic type switching properties are fabricated using vacuum deposition techniques. The devices are fabricated in a planar configuration and consist of amorphous tin selenide deposited over silver contacts. Results obtained indicate that Ovonic type memory switching does occur in these films with the energy density required for switching from a high impedance to a low impedance state being dependent on the spacing between the electrodes of the device. There is also a strong implication that the switching is a function of the magnitude of the applied voltage pulse.

  18. Evaluating the potential for high thermoelectric efficiency of silver selenide

    E-print Network

    Martin, Alain

    for cooling applications as well as up to 600 K for waste heat recovery. 1 Introduction Thermoelectric application of an electric current, show promise as efficient harvesters of waste heat from industrialEvaluating the potential for high thermoelectric efficiency of silver selenide Tristan Day,a Fivos

  19. Tin-related double acceptors in gallium selenide single crystals

    NASA Astrophysics Data System (ADS)

    Sánchez-Royo, J. F.; Errandonea, D.; Segura, A.; Roa, L.; Chevy, A.

    1998-05-01

    Gallium selenide single crystals doped with different amounts of tin are studied through resistivity and Hall effect measurements in the temperature range from 30 to 700 K. At low doping concentration tin is shown to behave as a double acceptor impurity in gallium selenide with ionization energies of 155 and 310 meV. At higher doping concentration tin also introduces deep donor levels, but the material remains p-type in the whole studied range of tin doping concentrations. The deep character of donors in gallium selenide is discussed by comparison of its conduction band structure to that of indium selenide under pressure. The double acceptor center is proposed to be a tin atom in interlayer position, with a local configuration that is similar to that of tin diselenide. The hole mobility exhibits an anomalous dependence on the tin content, attaining its maximum value in the ingot with 0.2% nominal tin content. This is proposed to be related to impurity pairing effects giving rise to thermal shallow acceptors with low ionization energy and low carrier scattering cross section, making the hole mobility to be controlled by phonon scattering mechanisms even for relatively high impurity content.

  20. 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.

  1. Copper Test

    MedlinePLUS

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

  2. Synthesis of cadmium selenide colloidal quantum dots in aquatic medium

    NASA Astrophysics Data System (ADS)

    Mazing, D. S.; Matyushkin, L. B.; Aleksandrova, O. A.; Mikhailov, I. I.; Moshnikov, V. A.; Tarasov, S. A.

    2014-12-01

    Cadmium selenide nanocrystals were prepared in water phase through facile wet chemistry technique with thioglycolic acid (TGA) acting as capping agent. Structures were characterized using X-ray diffraction (XRD), UV-vis absorption and photoluminescence spectroscopies. Depending on synthesis conditions nanoparticles exhibit photoluminescence with maximum in the region of 580 – 680 nm. Influence of technological parameters and component concentrations on nanocrystals average size and properties was studied.

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

    NASA Astrophysics Data System (ADS)

    Dagotto, Elbio

    2013-04-01

    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 AxFe2-ySe2 (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 iron-based 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.

  4. Sodium Selenide Toxicity Is Mediated by O2-Dependent DNA Breaks

    PubMed Central

    Dauplais, Marc; Lazard, Myriam; Beuneu, François; Decourty, Laurence; Malabat, Christophe; Jacquier, Alain; Blanquet, Sylvain; Plateau, Pierre

    2012-01-01

    Hydrogen selenide is a recurrent metabolite of selenium compounds. However, few experiments studied the direct link between this toxic agent and cell death. To address this question, we first screened a systematic collection of Saccharomyces cerevisiae haploid knockout strains for sensitivity to sodium selenide, a donor for hydrogen selenide (H2Se/HSe?/Se2?). Among the genes whose deletion caused hypresensitivity, homologous recombination and DNA damage checkpoint genes were over-represented, suggesting that DNA double-strand breaks are a dominant cause of hydrogen selenide toxicity. Consistent with this hypothesis, treatment of S. cerevisiae cells with sodium selenide triggered G2/M checkpoint activation and induced in vivo chromosome fragmentation. In vitro, sodium selenide directly induced DNA phosphodiester-bond breaks via an O2-dependent reaction. The reaction was inhibited by mannitol, a hydroxyl radical quencher, but not by superoxide dismutase or catalase, strongly suggesting the involvement of hydroxyl radicals and ruling out participations of superoxide anions or hydrogen peroxide. The •OH signature could indeed be detected by electron spin resonance upon exposure of a solution of sodium selenide to O2. Finally we showed that, in vivo, toxicity strictly depended on the presence of O2. Therefore, by combining genome-wide and biochemical approaches, we demonstrated that, in yeast cells, hydrogen selenide induces toxic DNA breaks through an O2-dependent radical-based mechanism. PMID:22586468

  5. Synthesis and characterization of inorganic-organic hybrid gallium selenides.

    PubMed

    Ewing, Sarah J; Vaqueiro, Paz

    2014-09-01

    Two semiconducting hybrid gallium selenides, [Ga6Se9(C6H14N2)4][H2O] (1) and [C6H14N2][Ga4Se6(C6H14N2)2] (2), were prepared using a solvothermal method in the presence of 1,2-diaminocyclohexane (1,2-DACH). Both materials consist of neutral inorganic layers, in which 1,2-DACH is covalently bonded to gallium. In 1, the organic amine acts as a monodentate and a bidentate ligand, while in 2, bidentate and uncoordinated 1,2-DACH molecules coexist. PMID:25113435

  6. Brush plating of tin(II) selenide thin films

    NASA Astrophysics Data System (ADS)

    Subramanian, B.; Sanjeeviraja, C.; Jayachandran, M.

    2002-01-01

    Brush plating technique has been adopted for the first time to coat tin selenide thin film on tin oxide coated conducting substrates at room temperature, 50°C and 60°C. Uniform and pinhole free films were deposited at potentials 5.0 V. XRD analyses show the polycrystalline nature of the films with orthorhombic structure. Optical studies show the indirect nature with a bandgap of 1.0 eV. SEM pictures show smooth and uniform surface morphology with a grain size of about 0.3 ?m. Film roughness was characterized by atomic force microscopy. Mott-Schottky plot has been drawn to evaluate the semiconductor parameters.

  7. Preparation and characterization of flash evaporated tin selenide thin films

    NASA Astrophysics Data System (ADS)

    Hema Chandra, G.; Naveen Kumar, J.; Madhusudhana Rao, N.; Uthanna, S.

    2007-08-01

    Tin selenide thin films were grown by flash evaporation method at substrate temperatures, TS=303-513 K at an interval of 30 K. Single phase, nearly stoichiometric and polycrystalline films with strong (4 0 0) orientation exhibiting orthorhombic structure was observed at the substrate temperature of 513 K. The optical absorption studies indicated a direct band gap of 1.26 eV with high absorption coefficient (>10 4 cm -1) near the fundamental absorption edge. The films were found to have an electrical resistivity 8.1 ? cm with p-type conduction.

  8. Study on flash-evaporated tin selenide films

    NASA Astrophysics Data System (ADS)

    Singh, Taminder; Kaur, Surinder; Bedi, R. K.

    1992-02-01

    Tin selenide films have been prepared by flash evaporation technique onto glass substrates kept at different temperatures. An appreciable increase in grain size has been observed with increase in substrate temperature, grain size as large as 0.43 m has been obtained for the films deposited at 523 K. Observations reveal that SnSe films appear to be p-type and poly-crystalline in nature. The activation energy shows an abrupt increase beyond substrate temperature of 523 K, indicating poor crystallinity and short range order. The mobility and carrier concentration of SnSe films increases with increase in temperature.

  9. 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.

  10. 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). ...

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

    SciTech Connect

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

    2013-06-15

    Five quinternary selenides, Sr{sub 2.63}Y{sub 0.37}Ge{sub 0.63}Sb{sub 2.37}Se{sub 8} (I), Sr{sub 2.63}La{sub 0.37}Ge{sub 0.63}Sb{sub 2.37}Se{sub 8} (II), Sr{sub 2.71}La{sub 0.29}Sn{sub 0.77}Bi{sub 2.23}Se{sub 8} (III), Ba{sub 2.67}La{sub 0.33}Sn{sub 0.67}Sb{sub 2.33}Se{sub 8} (IV), and Ba{sub 2.67}La{sub 0.33}Sn{sub 0.67}Bi{sub 2.33}Se{sub 8} (V), were synthesized by solid-state reaction in fused silica tubes. These compounds are isostructural and crystallize in the Sr{sub 3}GeSb{sub 2}Se{sub 8} structural-type, which belongs to the orthorhombic space group Pnma (no. 62). Three structural units, {sup 1}{sub ?}[MSe{sub 3}], {sup 1}{sub ?}[M{sub 4}Se{sub 10}] (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{sub 2.67}M{sub 0.33}Tt{sub 0.67}Pn{sub 2.33}Se{sub 8} (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, {sup 1}{sub ?}[MSe{sub 3}] and {sup 1}{sub ?}[M{sub 4}Se{sub 10}] (M=Tt, Pn), construct the one-dimensional structure. • Calculations of electronic structure confirm site preference of Sr/La sites.

  12. Photoinduced synthesis of unsymmetrical diaryl selenides from triarylbismuthines and diaryl diselenides

    PubMed Central

    Kobiki, Yohsuke; Kawaguchi, Shin-ichi; Ohe, Takashi

    2013-01-01

    Summary A novel method of photoinduced synthesis of unsymmetrical diaryl selenides from triarylbismuthines and diaryl diselenides has been developed. Although the arylation reactions with triarylbismuthines are usually catalyzed by transition-metal complexes, the present arylation of diaryl diselenides with triarylbismuthines proceeds upon photoirradiation in the absence of transition-metal catalysts. A variety of unsymmetrical diaryl selenides can be conveniently prepared by using this arylation method. PMID:23843906

  13. 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.

  14. Nanopatterned cadmium selenide Langmuir-Blodgett platform for leukemia detection.

    PubMed

    Sharma, Aditya; Pandey, Chandra M; Matharu, Zimple; Soni, Udit; Sapra, Sameer; Sumana, Gajjala; Pandey, Manoj K; Chatterjee, Tathagat; Malhotra, Bansi D

    2012-04-01

    We present results of the studies relating to preparation of Langmuir-Blodgett (LB) monolayers of tri-n-octylphosphine oxide-capped cadmium selenide quantum dots (QCdSe) onto indium-tin oxide (ITO) coated glass substrate. The monolayer behavior has been studied at the air-water interface under various subphase conditions. This nanopatterned platform has been explored to fabricate an electrochemical DNA biosensor for detection of chronic myelogenous leukemia (CML) by covalently immobilizing the thiol-terminated oligonucleotide probe sequence via a displacement reaction. The results of electrochemical response studies reveal that this biosensor can detect target DNA in the range of 10(-6) to 10(-14) M within 120 s, has a shelf life of 2 months, and can be used about 8 times. Further, this nucleic acid sensor has been found to distinguish the CML-positive and the control negative clinical patient samples. PMID:22380657

  15. Observation of inverse spin Hall effect in bismuth selenide

    NASA Astrophysics Data System (ADS)

    Deorani, Praveen; Son, Jaesung; Banerjee, Karan; Koirala, Nikesh; Brahlek, Matthew; Oh, Seongshik; Yang, Hyunsoo

    2014-09-01

    Bismuth Selenide (Bi2Se3) is a topological insulator exhibiting helical spin polarization and strong spin-orbit coupling. The spin-orbit coupling links the charge current to spin current via the spin Hall effect (SHE). We demonstrate a Bi2Se3 spin detector by injecting the pure spin current from a magnetic permalloy layer to a Bi2Se3 thin film and detect the inverse SHE in Bi2Se3. The spin Hall angle of Bi2Se3 is found to be 0.0093 ± 0.0013 and the spin diffusion length in Bi2Se3 to be 6.2 ± 0.15 nm at room temperature. Our results suggest that topological insulators with strong spin-orbit coupling can be used in functional spintronic devices.

  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. Synthesis of colloidal nanoscaled copper-indium-gallium-selenide (CIGS) particles for photovoltaic applications.

    PubMed

    Mousavi, S H; Müller, T S; de Oliveira, P W

    2012-09-15

    In this work, Cu(In,Ga)Se(2) (CIGS) nanoparticles were synthesized using a wet chemical method. The method is based on a non-vacuum thermal process that does not use selenization. The effects of temperature, source materials, and growth conditions on the phase and particle size were investigated. X-ray diffraction results confirm the formation of a tetragonal CIGS structure as the main phase with the purity more than 99% obtained by energy-dispersive X-ray spectroscopy (EDX). The morphology and size of the samples were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Using these methods, 20-80nm particles were obtained. Through measurements of the absorption spectra of CIGS nanoparticles, the band gap of the synthesized material was determined to be about 1.44eV, which corresponds to an acceptable wavelength region for absorber layers in solar cells. PMID:22762985

  18. Copper indium gallium (di)selenide: Electronic activities of grain boundaries and solar cell fabrication studies

    NASA Astrophysics Data System (ADS)

    Erkan, Mehmet Eray

    This dissertation is composed of three studies related to chalcopyrite solar cells. The first study is on electronic activities of grain boundaries (GBs) in CuInSe2 (CIS). Despite being polycrystalline, chalcopyrite thin film solar cells have reached record power conversion efficiencies. This is against the classical understanding on the effect of GBs in semiconductor materials. Because GBs are expected to be recombination centers and barriers against the carrier flow, reducing the device efficiency. Therefore, a complete understanding on the electronic behavior of chalcopyrite GBs is missing. Moreover, the high efficiency chalcopyrite solar cells are grown with Na impurities which positively affect the performance of the solar cell, so-called sodium effect. Research on chalcopyrite GBs has been coupled with the effect of Na impurities, because Na has been found segregated at the GBs. The study presented in this dissertation was performed on GBs in a Na-free CIS. It is important to study the GBs in a Na-free chalcopyrite to avoid any uncontrolled effects of Na segregation at the GBs, for instance a possible Na-related secondary phase formation which would affect the conclusions drawn on the natural behavior of chalcopyrite GBs. In addition, it is known that Sigma3 GBs in chalcopyrite solar cells are abundant; therefore, it is meaningful to investigate the differences between Sigma3 and non-Sigma3 GBs. For this purpose, Sigma3, close to Sigma3 and Sigma9 GBs in a Bridgman-grown multicrystalline Na-free CIS wafer were identified by electron backscatter diffraction and their electronic properties were investigated by Kelvin probe force microscope and cathodoluminescence in scanning electron microscope. It is shown that the Sigma3 GB is neutral and it does not behave as a recombination center, whereas once the geometry of a GB deviates from the Sigma3 geometry, such as close to Sigma3 and Sigma9 GBs, the GB becomes charged and behaves as a recombination center. This result was concluded to be due to the increase in the amount of defects at the GB that introduce midgap states as the Sigma value increases. Our results indicate that the surprising high performance seen in the polycrystalline chalcopyrite solar cells is possibly due to the abundance of electrically inactive Sigma3 GBs in this material. To investigate the effect of Na on CIS GBs, projected work includes the characterization of Sigma3 and non-Sigma3 GBs in CIS wafers grown with increasing Na concentration. Consequently, it will be possible to answer the following questions on the impact of sodium-effect on GBs: Is there a certain Na concentration for Na to affect the GB electrical properties and how does it affect both Sigma3 and non-Sigma3 GBs? In the second study, the use of selenoamide instead of direct use of H2Se for atmospheric pressure selenization reaction is proposed and its feasibility is shown by fabricating CIS solar cells with up to 1.6% power conversion efficiency. In addition, observed In and Ga segregation towards the bottom of the CIS and CIGS thin films, respectively, are investigated through phase transformations occurring during the selenization and systematically designed annealing processes. The third study is on the effect of flow type on the growth kinetics of CdS thin films deposited by chemical bath deposition. CdS thin films are deposited on glass substrates under turbulent and laminar flow conditions only by changing the substrate's alignment with respect to the bottom of the beaker in unstirred bath. It is shown that the flow condition of the bath does not change the optical and structural properties of CdS; however, deposition under laminar flow is explained to be diffusion-limited, whereas it is feed-limited under turbulent flow.

  19. 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.

  20. Novel Film Formation Pathways for Copper Zinc Tin Selenide for Solar Cell Applications

    NASA Astrophysics Data System (ADS)

    Bendapudi, Sree Satya Kanth

    Because of the anticipated high demand for Indium, ongoing growth of CIGS technology may be limited. Kesterite materials, which replace In with a Zn/Sn couple, are thought to be a solution to this issue. However, efficiencies are still below the 10% level, and these materials are proving to be complex. Even determination of the bandgap is not settled because of the occurrence of secondary phases. We use a film growth process, 2SSS, which we believe helps control the formation of secondary phases. Under the right growth conditions we find 1/1 Zn/Sn ratios and XRD signatures for Cu2ZnSnSe 4 with no evidence of secondary phases. The optical absorption profile of our films is also a good match to the CIS profile even for films annealed at 500°C. We see no evidence of phase separation. The effect of intentional variation of the Zn/Sn ratio on material and device properties is also presented.

  1. Copper hypersensitivity.

    PubMed

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

    2014-10-01

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

  2. 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.

  3. 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.

  4. Dispersion strengthened copper

    SciTech Connect

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

    1988-12-05

    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.

  5. 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.

  6. 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

    2015-04-01

    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. PMID:25798738

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

    NASA Astrophysics Data System (ADS)

    Chung, Ming-Yan; Lee, Chi-Shen

    2013-06-01

    Five quinternary selenides, Sr2.63Y0.37Ge0.63Sb2.37Se8 (I), Sr2.63La0.37Ge0.63Sb2.37Se8 (II), Sr2.71La0.29Sn0.77Bi2.23Se8 (III), Ba2.67La0.33Sn0.67Sb2.33Se8 (IV), and Ba2.67La0.33Sn0.67Bi2.33Se8 (V), were synthesized by solid-state reaction in fused silica tubes. These compounds are isostructural and crystallize in the Sr3GeSb2Se8 structural-type, which belongs to the orthorhombic space group Pnma (no. 62). Three structural units, [M]?1, [MSe10]?1 (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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

  9. Methylation and demethylation of intermediates selenide and methylselenol in the metabolism of selenium

    SciTech Connect

    Ohta, Yuki [Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo, Chiba 260-8675 (Japan); Suzuki, Kazuo T. [Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo, Chiba 260-8675 (Japan)], E-mail: ktsuzuki@p.chiba-u.ac.jp

    2008-01-15

    All nutritional selenium sources are transformed into the assumed common intermediate selenide for the syntheses of selenoproteins for utilization and/or of selenosugar for excretion. Methylselenol [monomethylselenide, MMSe] is the assumed intermediate leading to other methylated metabolites, dimethylselenide (DMSe) and trimethylselenonium (TMSe) for excretion, and also to the intermediate selenide from methylselenocysteine and methylseleninic acid (MSA). Here, related methylation and demethylation reactions were studied in vitro by providing chemically reactive starting substrates ({sup 76}Se-selenide, {sup 77}Se-MMSe and {sup 82}Se-DMSe) which were prepared in situ by the reduction of the corresponding labeled proximate precursors ({sup 76}Se-selenite, {sup 77}Se-MSA and {sup 82}Se-dimethylselenoxide (DMSeO), respectively) with glutathione, the three substrates being incubated simultaneously in rat organ supernatants and homogenates. The resulting chemically labile reaction products were detected simultaneously by speciation analysis with HPLC-ICP-MS after converting the products and un-reacted substrates to the corresponding oxidized derivatives (selenite, MSA and DMSeO). The time-related changes in selenium isotope profiles showed that demethylation of MMSe to selenide was efficient but that of DMSe to MMSe was negligible, whereas methylation of selenide to MMSe, and MMSe to DMSe were efficient, and that of DMSe to TMSe occurred less efficiently. The present methylation and demethylation reactions on equilibrium between selenide, MMSe and DMSe without producing selenosugar and selenoproteins indicated that DMSe rather than TMSe is produced as the end product, suggesting that DMSe is to be excreted more abundantly than TMSe. Organ-dependent differences in the methylation and demethylation reactions were characterized for the liver, kidney and lung.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Draft Genome Sequence of Pseudomonas aeruginosa Strain RB, a Bacterium Capable of Synthesizing Cadmium Selenide Nanoparticles

    PubMed Central

    Ayano, Hiroyuki; Kuroda, Masashi; Soda, Satoshi

    2014-01-01

    Pseudomonas aeruginosa strain RB is a bacterium capable of synthesizing cadmium selenide (CdSe) nanoparticles and was isolated from a soil sample. Here, we present the draft genome sequence of P. aeruginosa strain RB. To the best of our knowledge, this is the first report of a draft genome of a CdSe-synthesizing bacterium. PMID:24831140

  15. 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 ...

  16. Synthesis and optical properties of cadmium selenide quantum dots for white light-emitting diode application

    SciTech Connect

    Xu, Xianmei; Wang, Yilin; Gule, Teri; Luo, Qiang [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China); Zhou, Liya, E-mail: zhouliyatf@163.com [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China); Gong, Fuzhong [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China)

    2013-03-15

    Highlights: ? Stable CdSe QDs were synthesized by the one-step and two-level process respectively. ? The fabricated white LEDs show good white balance. ? CdSe QDs present well green to yellow band luminescence. ? CdSe QDs displayed a broad excitation band. - Abstract: Yellow light-emitting cadmium selenide quantum dots were synthesized using one-step and two-step methods in an aqueous medium. The structural luminescent properties of these quantum dots were investigated. The obtained cadmium selenide quantum dots displayed a broad excitation band suitable for blue or near-ultraviolet light-emitting diode applications. White light-emitting diodes were fabricated by coating the cadmium selenide samples onto a 460 nm-emitting indium gallium nitrite chip. Both samples exhibited good white balance. Under a 20 mA working current, the white light-emitting diode fabricated via the one-step and two-step methods showed Commission Internationale de l’Éclairage coordinates at (0.27, 0.23) and (0.27, 0.33), respectively, and a color rendering index equal to 41 and 37, respectively. The one-step approach was simpler, greener, and more effective than the two-step approach. The one-step approach can be enhanced by combining cadmium selenide quantum dots with proper phosphors.

  17. 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.

  18. A convenient and stereoselective synthesis of (Z)-allyl selenides via Sm/TMSCl system-promoted coupling of Baylis-Hillman adducts with diselenides*

    PubMed Central

    Liu, Yun-kui; Xu, Dan-qian; Xu, Zhen-yuan; Zhang, Yong-min

    2006-01-01

    A simple and convenient procedure for stereoselective synthesis of (Z)-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCl system to form selenide anions, which then undergo SN2? substitution of Baylis-Hillman adducts to produce the (Z)-allyl selenides. PMID:16615170

  19. Bis[3-methyl-5-(pyridin-2-yl)-1H-pyrazol-4-yl] selenide methanol hemisolvate

    PubMed Central

    Seredyuk, Maksym; Sharkina, Natalia O.; Gumienna-Kontecka, Elzbieta; Kapshuk, Anatoly A.

    2014-01-01

    The asymmetric unit of the title compound, C18H16N6Se·0.5CH3OH, contains two independent mol­ecules of bis­[3-methyl-5-(pyridin-2-yl)-1H-pyrazol-4-yl] selenide with similar C—Se—C bond angles [99.30?(14) and 98.26?(13)°], and a methanol molecule of solvation. In one mol­ecule, the dihedral angles between pyrazole and neighbouring pyridine rings are 18.3?(2) and 15.8?(2)°, and the corresponding angles in the other mol­ecule are 13.5?(2) and 8.3?(2)°. In the crystal, the selenide and solvent mol­ecules are linked by classical O—H?N and N—H?N hydrogen bonds, as well as by weak C—H?O and C—H?? inter­actions, forming a three-dimensional supra­molecular architecture. PMID:24764855

  20. 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.

  1. Preparation and antibacterial activity studies of degraded polysaccharide selenide from Enteromorpha prolifera.

    PubMed

    Lü, Haitao; Gao, Yujie; Shan, Hu; Lin, Yingting

    2014-07-17

    Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities, but its molecular weight was greatly high which influenced the activity. Organic Se had higher biological activities and was safer than inorganic Se species. In the present study, degraded polysaccharide selenide (Se-LEP) was synthesized from sodium selenite and degraded polysaccharide (LEP) with the catalysis of nitric acid. The preparation conditions of LEP and Se-LEP were optimized by orthogonal experiments. The selenite ester group was formed, and the selenium content was 1335.27 µg/g. The thermal stability of Se-LEP decreased. LEP had less inhibitory effects on bacteria and plant pathogenic fungi. Se-LEP had stronger inhibitory effect on Eschetichia coli, and weaker inhibitory effect on Staphylococcus aureus than polysaccharide selenide (Se-EP). Se-LEP also had better inhibitory effects on plant pathogenic fungi. PMID:24702923

  2. What is the true parent state in alkali-doped Iron Selenides

    NASA Astrophysics Data System (ADS)

    Li, Wei; Dong, Shuai; Fang, Chen; Hu, Jiangping

    2012-02-01

    By performing first-principles electronic structure calculations and analyzing effective magnetic model of alkali-doped iron selenides, we show that the materials without iron vacancies should approach a novel checkerboard phase in which each four Fe sites group together in tetragonal structure. The checkerboard phase is the ground state with a block antiferromagnetic (AFM) order and a small charge density wave order in the absence of superconductivity. Both of them can also coexist with superconductivity. The results explain mysterious 2 by 2 ordered patterns and hidden orders observed in various different experiments, clarify the missing link between AFM and superconducting phases, suggest that the block-AFM state is the parent state, and unify the understanding of various observed phases in alkali-doped iron selenides. (Reference: Wei Li, et al, arxiv:1110.0372 (2011)

  3. 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.

  4. Magnetic Properties of Iron Selenide Nanocrystals Synthesized by the Thermal Decomposition

    Microsoft Academic Search

    Chun-Rong Lin; Yu-Jhan Siao; Shin-Zong Lu; Chie Gau

    2009-01-01

    Iron selenide nanocrystals with hexagonal (H) and monoclinic (M) NiAs-like structure were synthesized via a one-pot thermal decomposition of ferrous chloride and Se powder in oleylamine. Magnetic measurements indicate that the Curie temperature of the synthesized hexagonal phase and monoclinic phase is 453 K and 340 K, respectively. The obtained magnetization sigma1.1tau (300 K) for H-phase and M-phase are respectively

  5. A study of the reactions of arsinic and arsonic acids with hydrogen sulfide and hydrogen selenide

    E-print Network

    Applegate, Cynthia Annette

    1986-01-01

    of phenylcarboxymethylarsinic acid with hydrogen selenide produced 1, 4-diphenyl-1, 4-diarsa-2, 3, 5-triselenacyclopentane. The structure of this compound was determined by single crystal x-ray crystallography. The reactions of a series of arsonic acids including phenyl, p-methyl... OF CONTENTS (CONTINUED) Page Synthesis of 1, 4-Diphenyl-1, 4-diarsa-2, 3, 5-triselenacyclopentane Synthesis of 1, 4-Diphenyl-1, 4-diarsa-2, 3, 5-trithiacyclopentane Reaction of Phenylcarboxymethylarsinic Acid with Benzenethiol Synthesis of Phenyl Di...

  6. Room temperature growth of nanocrystalline tin (II) selenide from aqueous solution

    NASA Astrophysics Data System (ADS)

    Zhang, Weixin; Yang, Zeheng; Liu, Juewen; Zhang, Lei; Hui, Zehua; Yu, Weichao; Qian, Yitai; Chen, Lin; Liu, Xianming

    2000-07-01

    Sheet-like nanocrystalline SnSe with an orthorhombic phase has been prepared via a reaction between a selenium alkaline aqueous solution and tin (II) complex at room temperature under atmospheric pressure. The XRD pattern indicated that the selenium alkaline solution as a selenium source, made the product to crystallize well at room temperature. The XPS analysis indicated that the purity of the product was quite high. The mechanism of the formation of tin (II) selenide was discussed.

  7. Syntheses of sulfides and selenides through direct oxidative functionalization of C(sp3)-H bond.

    PubMed

    Du, Bingnan; Jin, Bo; Sun, Peipei

    2014-06-01

    A new protocol for C-S and C-Se bond formation by the direct functionalization of the C(sp(3))-H bond of alkanes under metal-free conditions was developed. Using (t)BuOO(t)Bu as the oxidant, the reaction of disulfides or diselenides with alkanes gave sulfides or selenides in moderate to good yields. The method was very simple and atom-economical. PMID:24835082

  8. 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, ...

  9. 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 ...

  10. 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.

  11. COPPER CORROSION RESEARCH UPDATE

    EPA Science Inventory

    Copper release and corrosion related issues continue to be important to many water systems. The objective of this presentation is to discuss the current state of copper research at the USEPA. Specifically, the role of aging on copper release, use of phosphates for copper corrosio...

  12. 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

  13. 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.

  14. [Effect of silver/zinc selenide core-shell structure spheres on the infrared absorption properties of sodium nitrate].

    PubMed

    Guo, Qiang; Li, Chun; Jia, Zhi-Jun; Yuan, Guang

    2013-10-01

    Silver/zinc selenide (Ag/ZnSe) core-shell structure spheres were made through the method of silver mirror reaction on zinc selenide micro spheres. Surface morphology of the spheres was depicted by scanning electron microscopy, X-ray diffraction and Fourier infrared absorption spectrum. This paper studies the effect of Ag/ZnSe core-shell structure spheres on the infrared absorption properties of sodium nitrate solution. The results show that, the anti-symmetric vibration absorption peaks of nitrate are blue-shifted, and the intensity are improved obviously by the effect of core-shell structure spheres. PMID:24409704

  15. Selenide and telluride glasses for mid-infrared bio-sensing

    NASA Astrophysics Data System (ADS)

    Cui, Shuo; Chahal, Radwan; Shpotyuk, Yaroslav; Boussard, Catherine; Lucas, Jacques; Charpentier, Frederic; Tariel, Hugues; Loréal, Olivier; Nazabal, Virginie; Sire, Olivier; Monbet, Valérie; Yang, Zhiyong; Lucas, Pierre; Bureau, Bruno

    2014-02-01

    Fiber Evanescent Wave Spectroscopy (FEWS) is an efficient way to collect optical spectra in situ, in real time and even, hopefully, in vivo. Thanks to selenide glass fibers, it is possible to get such spectra over the whole mid-infrared range from 2 to 12 ?m. This working window gives access to the fundamental vibration band of most of biological molecules. Moreover selenide glasses are stable and easy to handle, and it is possible to shape the fiber and create a tapered sensing head to drastically increase the sensitivity. Within the past decades, numerous multi-disciplinary studies have been conducted in collaboration with the City Hospital of Rennes. Clinical trials have provided very promising results in biology and medicine which have led to the creation in 2011 of the DIAFIR Company dedicated to the commercialization of fiber-based infrared biosensors. In addition, new glasses based on tellurium only have been recently developed, initially in the framework of the Darwin mission led by the European Space Agency (ESA). These glasses transmit light further into the far-infrared and could also be very useful for medical applications in the near future. Indeed, they permit to reach the vibrational bands of biomolecules laying from 12 to 16 ?m where selenide glasses do not transmit light anymore. However, while Se is a very good glass former, telluride glasses tend to crystallize easily due to the metallic nature of Te bonds. Hence, further work is under way to stabilize the glass composition for fibers drawing and to lower the optical losses for improving their sensitivity as bio-sensors.

  16. Transparent and flexible nonvolatile memory using poly(methylsilsesquioxane) dielectric embedded with cadmium selenide quantum dots

    NASA Astrophysics Data System (ADS)

    Ooi, Poh Choon; Li, Fushan; Perumal Veeramalai, Chandrasekar; Guo, Tailiang

    2014-12-01

    In this work, a transparent and flexible nonvolatile memory was fabricated using a solution process. The conduction mechanisms of the metal/insulator/metal structure consisting of cadmium selenide quantum dots embedded in poly(methylsilsesquioxane) dielectric layers were investigated in terms of current–voltage characteristics. The memory device is reprogrammable and stable up to 1 × 104 s with little deterioration and a distinct ON/OFF ratio of 104. Endurance cycle and retention tests of the as-fabricated memory device were also carried out. The results indicate that the device has good operating stability.

  17. 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.

  18. 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.

  19. Tin U --centers formed through nuclear transformations in vitreous arsenic sulfides and selenides

    NASA Astrophysics Data System (ADS)

    Bordovsky, G. A.; Kozhokar', M. Yu.; Marchenko, A. V.; Naletko, A. S.; Seregin, P. P.

    2012-07-01

    It has been shown using the Mössbauer emission spectroscopy for isotope 119Sn that impurity tin atoms formed after the radioactive decay of 119Sb atoms in vitreous arsenic sulfide and selenide are localized in arsenic sites and play the role of two-electron centers with negative correlation energy. The most of daughter 119 m Sn atoms formed after the radioactive decay of the 119 m Te atoms in glasses are arranged in chalcogen sites; they are electrically inactive. Considerable recoil energy of daughter atoms in the case of decay of 119 m Te leads to the appearance of 119 m Sn atoms shifted from chalcogen sites.

  20. Dissimilatory Reduction of Elemental Selenium to Selenide in Sediments and Anaerobic Cultures of Selenium Respiring Bacteria

    NASA Astrophysics Data System (ADS)

    Herbel, M. J.; Switzer-Blum, J.; Oremland, R. S.

    2001-12-01

    Selenium contaminated environments often contain elemental Se (Se0) in their sediments that originates from dissimilatory reduction of Se oxyanions. The forms of Se in sedimentary rocks similarly contain high proportions of Se0, but much of the Se is also in the form of metal selenides, Se-2. It is not clear if the occurrence of these selenides is due to microbial reduction of Se0, or some other biological or chemical process. In this investigation we examined the possibility that bacterial respiratory reduction of Se0 to Se-2 could explain the presence of the latter species in sedimentary rocks. We conducted incubations of anoxic sediment slurries amended with different forms of Se0. High levels of Se0 (mM) were added to San Francisco Bay sediments in order to enhance the detection of soluble HSe-, which was precipitated with Cu2+ then redissolved and quantified by ICP-MS. Concentrations of HSe- were highest in live samples amended with red amorphous Se0 formed by either microbial reduction of Se+4 ("biogenic Se0") or by chemical oxidation of H2Se(g) ("chem. Se0"); very little HSe- was formed in those amended with black crystalline Se0, indicating the general lack of reactivity of this allotrope. Controls poisoned with 10% formalin did not produce HSe- from additions of chem. Se0. Reduction of both forms of red amorphous Se0 to HSe- occurred vigorously in growing cultures of Bacillus selenitireducens, an anaerobic halophile previously isolated from sediments of Mono Lake, CA. Up to 73% and 68% of red amorphous, biogenic Se0 or chem. Se0, respectively, was reduced to HSe- during growth of B. selenitireducens, (incubation time ~ 200 hrs): oxidation of lactate to acetate as well as cell density increases indicated that a dissimilatory reduction pathway was likely. Reduction was most enhanced when cells were previously grown on elemental sulfur or Se+4. In contrast to the growth experiments, washed cell suspensions of B. selenitireducens exhibited no HSe- production when amended with red amorphous or black Se0; however, they could convert up to 34% of added Se+4 to HSe- after its complete reduction to Se0 first occurred. These findings indicate that reduction of Se0 in sediments to HSe- or metal selenides is a bacterial dissimilatory processes, that explains the presence of selenides in some sedimentary rocks.

  1. 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.

    2015-01-01

    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.

  2. Influence of indium concentration on the structural and optoelectronic properties of indium selenide thin films

    NASA Astrophysics Data System (ADS)

    Yan, Yong; Li, Shasha; Yu, Zhou; Liu, Lian; Yan, Chuanpeng; Zhang, Yong; Zhao, Yong

    2014-12-01

    We have grown indium selenide thin films using magnetron sputtering method. The influence of indium concentration on the structural, optical and electrical properties was studied. The concentration of indium in indium selenide thin films was varied by adjusting the sputtering power from 40 to 80 W while keeping the substrate temperature and argon pressure constant. The ?-phase, which only exists at elevated temperatures in bulk single crystals, can persist at room temperature in the In-rich films. The ?-phase thin film with smaller band gap has an electrical resistivity about four orders of magnitude lower than that of the ?-In2Se3 thin film, which is also stable at room temperature. Furthermore, the single-phase ?-In2Se3 thin film was then assembled in visible-light photodetector which shows a fast, reversible, and stable response. These results indicate the possibility of using ?-In2Se3 thin film in various next-generation photoelectric and optical-memory applications.

  3. Transparent metal selenide alloy counter electrodes for high-efficiency bifacial dye-sensitized solar cells.

    PubMed

    Duan, Yanyan; Tang, Qunwei; Liu, Juan; He, Benlin; Yu, Liangmin

    2014-12-22

    The exploration of cost-effective and transparent counter electrodes (CEs) is a persistent objective in the development of bifacial dye-sensitized solar cells (DSSCs). Transparent counter electrodes based on binary-alloy metal selenides (M-Se; M=Co, Ni, Cu, Fe, Ru) are now obtained by a mild, solution-based method and employed in efficient bifacial DSSCs. Owing to superior charge-transfer ability for the I(-) /I3 (-) redox couple, electrocatalytic activity toward I3 (-) reduction, and optical transparency, the bifacial DSSCs with CEs consisting of a metal selenide alloy yield front and rear efficiencies of 8.30?% and 4.63?% for Co0.85 Se, 7.85?% and 4.37?% for Ni0.85 Se, 6.43?% and 4.24?% for Cu0.50 Se, 7.64?% and 5.05?% for FeSe, and 9.22?% and 5.90?% for Ru0.33 Se in comparison with 6.18?% and 3.56?% for a cell with an electrode based on pristine platinum, respectively. Moreover, fast activity onset, high multiple start/stop capability, and relatively good stability demonstrate that these new electrodes should find applications in solar panels. PMID:25358619

  4. PREPARATION AND PROPERTIES OF THE SINGLE CRYSTALLINE ABâ-TYPE SELENIDES AND TELLURIDES OF NIOBIUM, TANTALUM, MOLYBDENUM AND TUNGSTEN

    Microsoft Academic Search

    L Brixner

    1962-01-01

    The ABâ-type selenides and tellurides of niobium, tantalum, ; molybdenum, and tungsten were prepared in single crystalline form by means of ; transport reactions. Lattice parameters were determined on the basis of single ; crystal patterns and are given for the eight compounds. Pertinent thermoelectric ; parameters, such as electrical resistlvity, Seebeck coefficient, and thermal ; conductivity were measured on

  5. HEALTH MATTERS Copper T IUD

    E-print Network

    Yener, Aylin

    HEALTH MATTERS Copper T IUD What is the Copper T IUD? The Copper T IUD is one of two types of intrauterine devices available in the United States. The Copper T IUD is a small, flexible device made of soft pregnancy. How effective is the Copper T IUD? The Copper T IUD is extremely effective and can last up to 12

  6. Copper: Technology & Standards

    NSDL National Science Digital Library

    Art Cohen

    This article explains modern copper mining, ore extraction, and casting processes and details innovative copper products, major markets, service activities, and the future of copper in industry and everyday life. It was published in the November 1998 issue of the online magazine Innovations.

  7. 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.

  8. Demystifying Controlling Copper Corrosion

    EPA Science Inventory

    The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

  9. Simulations of silver-doped germanium-selenide glasses and their response to radiation.

    PubMed

    Prasai, Kiran; Drabold, David A

    2014-01-01

    Chalcogenide glasses doped with silver have many applications including their use as a novel radiation sensor. In this paper, we undertake the first atomistic simulation of radiation damage and healing in silver-doped Germanium-selenide glass. We jointly employ empirical potentials and ab initio methods to create and characterize new structural models and to show that they are in accord with many experimental observations. Next, we simulate a thermal spike and track the evolution of the radiation damage and its eventual healing by application of a simulated annealing process. The silver network is strongly affected by the rearrangements, and its connectivity (and thus contribution to the electrical conductivity) change rapidly in time. The electronic structure of the material after annealing is essentially identical to that of the initial structure. PMID:25426005

  10. Intracavity doubling of a CO2 TEA laser with thallium-arsenic-selenide crystal

    NASA Astrophysics Data System (ADS)

    Pastel, Robert L.

    1987-05-01

    Intracavity doubling of a grating-tuned CO2 TEA laser was achieved by using a thallium-arsenic-selenide (TAS) crystal in the cavity. The TAS crystal used measured 3.7 cm long and 2.5 cm in diameter. The laser was tuned to the 9.58-micron P(24) line and apertured to obtain a TEM(00) mode, and A 13-mJ radiation at 4.8 microns was generated in one of the second harmonic beams from the CO2 laser (which normally emits 120 mJ of energy at 9.6 microns). The insertion loss of the doubling crystal was 17 percent. Thus, assuming the theoretical limit of 25-percent conversion efficiency predicted by Smith (1970), the doubling efficiency of this laser is limited to 12.5 percent.

  11. 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

  12. Pulsed laser ablation of zinc selenide in nitrogen ambience: Formation of zinc nitride films

    NASA Astrophysics Data System (ADS)

    Simi, S.; Navas, I.; Vinodkumar, R.; Chalana, S. R.; Gangrade, Mohan; Ganesan, V.; Pillai, V. P. Mahadevan

    2011-09-01

    Zinc nitride (Zn 3N 2) thin films are prepared using pulsed laser deposition (PLD) from zinc selenide (ZnSe) target at different nitrogen ambient pressures viz. 1, 3, 5, 7 and 10 Pa. The films prepared with nitrogen pressures 1 and 3 Pa are amorphous in nature, whereas the films prepared at 5, 7 and 10 Pa exhibit the presence of cubic bixbyite Zn 3N 2 structure with lattice parameter very close to bulk of Zn 3N 2. The particle size calculated by Debye Scherrer's formula is in the nano regime. Surface morphology of the films is studied by SEM and AFM analysis. Optical parameters such as band gap, refractive index and porosity of the films are calculated. Moreover, the present study confers an outlook about how do various factors such as substrate temperature, reactive supplementing gas and laser-target interaction influence the film developing process during pulsed lased deposition.

  13. The growth of zinc selenide single crystals by physical vapor transport in microgravity

    NASA Technical Reports Server (NTRS)

    Anderson, Elmer E.; Rosenberger, Franz E.; Cheng, Hai-Yuin

    1990-01-01

    Growth and characterization studies will be performed on zinc selenide single crystals. The high temperature outgassing behavior of the silica ampoule material will be studied in order to develop a cleaning and bake-out procedure that will minimize the amount of impurities introduced into the vapor from the ampoule materials and in particular during the seal-off procedure. The outgassing behavior of the ZnSe starting material will be studied during high vacuum refinement at elevated temperatures in order to develop a temperature pressure program that will optimize the removal of impurities while minimizing a shift in stoichiometry due to preferred evaporation of the higher fugacity component. The mass spectrometer system was completed, and after calibration, will be used to perform the above tasks. The system and its operation is described in detail.

  14. Organic molecules passivated Mn doped Zinc Selenide quantum dots and its properties

    NASA Astrophysics Data System (ADS)

    Archana, J.; Navaneethan, M.; Ponnusamy, S.; Hayakawa, Y.; Muthamizhchelvan, C.

    2011-06-01

    Quantum dots of Mn doped Zinc Selenide with N-Methylaniline as the capping agent was prepared by simple and inexpensive wet chemical method. Size of the particles observed by TEM was of the order of 2-4 nm which was well consistent with the size measured by UV analysis. The presence of paramagnetic substance Mn 2+ in the ZnSe quantum dots was confirmed by EPR measurement. Mn doped ZnSe nanoparticles exhibited a strong blue emission that was strongly dependent upon the Mn dopant level and the surface passivation produced by N-Methylaniline. The stability of the product was studied by thermal analysis which shows that this product is highly suitable for opto-electronic applications.

  15. 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

  16. Resonance enhancement of nonlinear photoluminescence in gallium selenide and related compounds

    SciTech Connect

    Angermann, Ch; Karich, P; Kador, Lothar; Allakhverdiev, K R; Baykara, T; Salaev, E Yu

    2012-05-31

    Maker fringe experiments on the layered chalcogenide semiconductor gallium selenide (GaSe) with weak cw diode lasers are presented. It is demonstrated that nonlinear photoluminescence emitted by this material and by the similar compound GaSe{sub 0.9}S{sub 0.1} under illumination with a 632.8-nm He - Ne laser shows very strong resonance enhancement upon heating when the absorption edge and exciton levels are shifted towards the laser line. The photoluminescence appears to be strongest when the energy level of the direct exciton, which emits it, is resonant with the photon energy of the laser. The previously observed enhancement of the photoluminescence by electric fields is interpreted in this context.

  17. Controllable synthesis of metal selenide heterostructures mediated by Ag2Se nanocrystals acting as catalysts

    NASA Astrophysics Data System (ADS)

    Zhou, Jiangcong; Huang, Feng; Xu, Ju; Wang, Yuansheng

    2013-09-01

    Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se-ZnSe, and even multi-segment heterostructures such as Ag2Se-CdSe-ZnSe and Ag2Se-ZnSe-CdSe, were successfully synthesized. Several interesting features were found in the Ag2Se based heterogrowth. At the initial stage of heterogrowth, a layer of the second phase forms on the surface of an Ag2Se nanosphere, with a curved junction interface between the two phases. With further growth of the second phase, the Ag2Se nanosphere tends to flatten the junction surface by modifying its shape from sphere to hemisphere in order to minimize the conjunct area and thus the interfacial energy. Notably, the crystallographic relationship of the two phases in the heterostructure varies with the lattice parameters of the second phase, in order to reduce the lattice mismatch at the interface. Furthermore, a small lattice mismatch at the interface results in a straight rod-like second phase, while a large lattice mismatch would induce a tortuous product. The reported results may provide a new route for developing novel selenide semiconductor heterostructures which are potentially applicable in optoelectronic, biomedical, photovoltaic and catalytic fields.Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se-ZnSe, and even multi-segment heterostructures such as Ag2Se-CdSe-ZnSe and Ag2Se-ZnSe-CdSe, were successfully synthesized. Several interesting features were found in the Ag2Se based heterogrowth. At the initial stage of heterogrowth, a layer of the second phase forms on the surface of an Ag2Se nanosphere, with a curved junction interface between the two phases. With further growth of the second phase, the Ag2Se nanosphere tends to flatten the junction surface by modifying its shape from sphere to hemisphere in order to minimize the conjunct area and thus the interfacial energy. Notably, the crystallographic relationship of the two phases in the heterostructure varies with the lattice parameters of the second phase, in order to reduce the lattice mismatch at the interface. Furthermore, a small lattice mismatch at the interface results in a straight rod-like second phase, while a large lattice mismatch would induce a tortuous product. The reported results may provide a new route for developing novel selenide semiconductor heterostructures which are potentially applicable in optoelectronic, biomedical, photovoltaic and catalytic fields. Electronic supplementary information (ESI) available: Fig. S1-S8 and Table S1. See DOI: 10.1039/c3nr03601d

  18. Counter electrodes from binary ruthenium selenide alloys for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Li, Pinjiang; Cai, Hongyuan; Tang, Qunwei; He, Benlin; Lin, Lin

    2014-12-01

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its merits on clean, cost-effectiveness, relatively high efficiency, and easy fabrication. However, the reduction of fabrication cost without sacrifice of power conversion efficiencies of the DSSCs is a golden rule for their commercialization. Here we design a new binary ruthenium selenide (Ru-Se) alloy counter electrodes (CEs) by a low-temperature hydrothermal reduction method. The electrochemical behaviors are evaluated by cyclic voltammogram, electrochemical impedance, and Tafel measurements, giving an optimized Ru/Se molar ratio of 1:1. The DSSC device with RuSe alloy CE achieves a power conversion efficiency of 7.15%, which is higher than 5.79% from Pt-only CE based DSSC. The new concept, easy process along with promising results provide a new approach for reducing cost but enhancing photovoltaic performances of DSSCs.

  19. Effect of cadmium selenide quantum dots on the dielectric and physical parameters of ferroelectric liquid crystal

    SciTech Connect

    Singh, D. P.; Gupta, S. K.; Manohar, R., E-mail: rajiv.manohar@gmail.com [Liquid Crystal Research Lab, Physics Department, University of Lucknow, Lucknow-226007 (India); Varia, M. C.; Kumar, S. [Soft Condensed Matter Laboratory, Raman Research Institute, C. V. Raman Avenue, Sadashivnagar, Bangalore 560080 (India); Kumar, A. [Department of Physics, Deshbandhu College, Delhi University, Delhi-110019 (India)

    2014-07-21

    The effect of cadmium selenide quantum dots (CdSe QDs) on the dielectric relaxation and material constants of a ferroelectric liquid crystal (FLC) has been investigated. Along with the characteristic Goldstone mode, a new relaxation mode has been induced in the FLC material due to the presence of CdSe QDs. This new relaxation mode is strongly dependent on the concentration of CdSe QDs but is found to be independent of the external bias voltage and temperature. The material constants have also been modified remarkably due to the presence of CdSe QDs. The appearance of this new relaxation phenomenon has been attributed to the concentration dependent interaction between CdSe QDs and FLC molecules.

  20. Optical and Structural Studies on Tin Selenide (SnSe) Multilayer Thin Films

    NASA Astrophysics Data System (ADS)

    Parvathi, M. Manonmani; Arivazhagan, V.; Mohan, A.; Rajesh, S.

    2011-10-01

    Multilayer structure of Tin Selenide thin films were prepared by thermal evaporation technique by successive coatings of Tin and Selenium metal powders. The number of layers varied from 3 to 11 during deposition on the glass substrate with 423 K temperature. The optical properties of the multilayer films studied using UV-Vis spectrophotometer. The absorption edge towards blue region shows the nanocrystalline effect of the films. The optical band gap values lies in the ranges of 2.6-3.2 eV. The structural studies reveals that the prepared films oriented at (0 0 1) plane with hexagonal structure. The crystalline size varies from 11-22 nm on the different multilayer films and discussed in this paper.

  1. Reaction chemistry and ligand exchange at cadmium-selenide nanocrystal surfaces.

    PubMed

    Owen, Jonathan S; Park, Jungwon; Trudeau, Paul-Emile; Alivisatos, A Paul

    2008-09-17

    The surface chemistry of cadmium selenide nanocrystals, prepared from tri-n-octylphosphine selenide and cadmium octadecylphosphonate in tri-n-octylphosphine oxide, was studied with 1H and {1H}31P NMR spectroscopy as well as ESI-MS and XPS. The identity of the surface ligands was inferred from reaction of nanocrystals with Me3Si-X (X = -S-SiMe3, -Se-SiMe3, -Cl and -S-(CH2CH2O)4OCH3)) and unambiguous assignment of the organic byproducts, O,O'-bis(trimethylsilyl)octadecylphosphonic acid ester and O,O'-bis(trimethylsilyl)ocatdecylphosphonic acid anhydride ester. Nanocrystals isolated from these reactions have undergone exchange of the octadecylphosphonate ligands for -X as was shown by 1H NMR (X = -S-(CH2CH2O)4OCH3) and XPS (X = -Cl). Addition of free thiols to as prepared nanocrystals results in binding of the thiol to the particle surface and quenching of the nanocrystal fluorescence. Isolation of the thiol-ligated nanocrystals shows this chemisorption proceeds without displacement of the octadecylphosphonate ligands, suggesting the presence of unoccupied Lewis-acidic sites on the particle surface. In the presence of added triethylamine, however, the octadecylphosphonate ligands are readily displaced from the particle surface as was shown with 1H and {1H}31P NMR. These results, in conjunction with previous literature reports, indicate that as-prepared nanocrystal surfaces are terminated by X-type binding of octadecylphosphonate moieties to a layer of excess cadmium ions. PMID:18722426

  2. Synthesis and characterization of a nickel selenide series via a hydrothermal process

    NASA Astrophysics Data System (ADS)

    Sobhani, Azam; Salavati-Niasari, Masoud

    2014-01-01

    A series of nickel selenides (NiSe and NiSe2) has been successfully synthesized from the reaction of SeCl4 with NiCl2?6H2O in the presence of cetyltrimethyl ammonium bromide (CTAB) as surfactant and hydrazine hydrate (N2H4?H2O) as reductant at 180 °C for 12 h through a simple hydrothermal method. The morphology, phase structure and composition of NixSey can be controlled by adjusting the Ni/Se ratio of the raw materials, the quantity of reductant, the reaction temperature and so forth. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) analysis. It was found that when the ratio of Ni/Se is 1:1 or 3:2, flower-like assemblies of NiSe nanosheets are formed, at 180 °C for 12 h. When the ratio of Ni/Se is 1:2 at 180 °C, the products are found to be the mixture of hexagonal NiSe and cubic NiSe2. With decrease of nickel content in molar ratio of 1:2 (Ni:Se), nanospheres are agglomerated and microstructures are formed. With the reaction temperature decreasing from 180 °C to 120 °C, we reach pure NiSe2 nanoparticles. The formation mechanism of the nickel selenides has been investigated in detail by means of XRD and SEM analyses.

  3. Achieving higher TC superconductivity in dense cuprates, iron selenides, and hydrocarbons

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-Jia

    2013-03-01

    Pressure plays an essential role in inducing or tuning superconductivity as well as shedding insight on the mechanism of superconductivity. There are much rich phase diagrams in unconventional superconductors under pressure. Finding ways to control the quantum coherence properties to have a higher critical temperature TC than the material has remains a challenge. Here we will talk about our recent experimental efforts in achieving higher temperature superconductivity in cuprates, iron selenides, and hydrocarbons. We will show how to enhance remarkably TC through the pressure tuning of competing electronic order in multilayer cuprates [1] and how to have superconductivity in two distinct regimes in iron selenides [2,3]. We will present a discovery of an enhancement of TC at more than doubled ambient value in a highly compressed aromatic hydrocarbon [4]. Our results have important implications for designing and engineering superconductors with much higher TCs at ambient conditions.[4pt] [1] X. J. Chen, V. V. Struzhkin, Y. Yu, A. F. Goncharov, C. T. Lin, H. K. Mao, and R. J. Hemley, Nature 466, 950-953 (2010).[0pt] [2] L. L. Sun, X. J. Chen, J. Guo, P. W. Gao, H. D. Wang, M. H. Fang, X. L. Chen, G. F. Chen, Q. Wu, C. Zhang, D. C. Gu, X. L. Dong, K. Yang, A. G. Li, X. Dai, H. K. Mao, and Z. X. Zhao, Nature 483, 67-69 (2012) .[0pt] [3] X. J. Chen, Q. Huang, S. B. Wang, J. X. Zhu, W. Bao, M. H. Fang, J. B. Zhang, L. Y. Tang, Y. M. Xiao, P. Chaw, J. Shu, W. L. Mao, V. V. Struzhkin, R. J. Hemley, and H. K. Mao, unpublished.[0pt] [4] X. J. Chen, X. F. Wang, Z. X. Qin, H. Wu, Q. Z. Huang, T. Muramatsu, J. J. Ying, P. Cheng, Z. J. Xiang, X. H. Chen, W. G. Yang, V. V. Struzhkin, and H. K. Mao, unpublished.

  4. 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

  5. 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

  6. Tin selenide synthesized by a chemical route: the effect of the annealing conditions in the obtained phase

    NASA Astrophysics Data System (ADS)

    Bernardes-Silva, Ana Cláudia; Mesquita, A. F.; de Moura Neto, E.; Porto, A. O.; de Lima, G. M.; Ardisson, J. D.; Lameiras, F. S.

    2005-09-01

    The effects of different annealing conditions over the tin selenide obtained from a chemical route are presented in this work. The tin selenide was annealed at 300 and 600 °C under hydrogen, nitrogen and argon atmospheres. The materials were characterized by X-ray diffraction and 119Sn Mössbauer spectroscopy. In the 'as synthetized' material a considerably amount of tin oxide (57%) was detected by Mössbauer spectroscopy. After thermal annealing the amount of these oxides varied according to the temperature and atmosphere used. At 600 °C/hydrogen the smallest amount of tin oxide was obtained (20%). These oxides were formed during the synthetic procedure through the hydrolysis of tin chloride used as reagent.

  7. Thermo-optical effect in zinc selenide windows for two-color interferometer for fusion plasma diagnostics

    Microsoft Academic Search

    Miguel Sa´nchez; Joaqui´n Sa´nchez

    2005-01-01

    After some improvements in the two-color interferometer for plasma density measurements in the TJII fusion device, an effect, which we attribute to the thermo-optical characteristics of zinc selenide windows, has been put in evidence. Part of the 53.2 GHz mm radiation, used to heat the plasma, heats the windows and produces an optical path length difference between the two laser

  8. Spin-flip Raman scattering studies of post-growth annealed p-type nitrogen-doped zinc selenide

    Microsoft Academic Search

    Catherine L. Orange; Daniel Wolverson; Bernhard Schlichtherle; J. John Davies; Ken-ichi Ogata; Shigeo Fujita

    1997-01-01

    Spin-flip Raman scattering (SFRS) studies of post-growth annealed p-type nitrogen-doped zinc selenide grown by photoassisted metallo-organic vapour phase epitaxy (MOVPE) are presented. Four pieces from the same parent structure were subjected to annealing times between 0 and 60 min in a nitrogen atmosphere at a temperature of 0268-1242\\/12\\/12\\/011\\/img9. The changes in net nitrogen acceptor concentration were determined via capacitance -

  9. Synthesis, structure, and thermal properties of soluble hydrazinium germanium(IV) and tin(IV) selenide salts.

    PubMed

    Mitzi, David B

    2005-05-16

    The crystal structures of two hydrazinium-based germanium(IV) and tin(IV) selenide salts are determined. (N(2)H(5))(4)Ge(2)Se(6) (1) [I4(1)cd, a = 12.708(1) Angstroms, c = 21.955(2) Angstroms, Z = 8] and (N(2)H(4))(3)(N(2)H(5))(4)Sn(2)Se(6) (2) [P, a = 6.6475(6) Angstroms, b = 9.5474(9) Angstroms, c = 9.8830(10) Angstroms, alpha = 94.110(2) degrees, beta = 99.429(2) degrees, gamma = 104.141(2) degrees, Z = 1] each consist of anionic dimers of edge-sharing metal selenide tetrahedra, M(2)Se(6)(4-) (M = Ge or Sn), separated by hydrazinium cations and, for 2, additional neutral hydrazine molecules. Substantial hydrogen bonding exists among the hydrazine/hydrazinium molecules as well as between the hydrazinium cations and the selenide anions. Whereas the previously reported tin(IV) sulfide system, (N(2)H(5))(4)Sn(2)S(6), decomposes cleanly to microcrystalline SnS(2) when heated to 200 degrees C in an inert atmosphere, higher temperatures (>300 degrees C) are required to dissociate selenium from 1 and 2 for the analogous preparations of single-phase metal selenides. The metal chalcogenide salts are highly soluble in hydrazine, as well as in a variety of amines and DMSO, highlighting the potential usefulness of these compounds as precursors for the solution deposition of the corresponding metal chalcogenide films. PMID:15877460

  10. 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.

  11. 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.

  12. 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.

  13. Improved Electroformed Structural Copper and Copper Alloys

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Hudson, W.; Babcock, B.; Edwards, R.

    1998-01-01

    Electroforming offers a superior means for fabricating internally cooled heat exchangers and structures subjected to thermal environments. Copper is deposited from many such applications because of the good thermal conductivity. It suffers from mediocre yield strength as a structural material and loses mechanical strength at intermediate temperatures. Mechanical properties similar to those of electroformed nickel are desired. Phase 1 examined innovative means to improve deposited copper structural performance. Yield strengths as high as 483 MPa (70 ksi) were obtained with useful ductility while retaining a high level of purity essential to good thermal conductivity. Phase 2 represents a program to explore new additive combinations in copper electrolytes to produce a more fine, equiaxed grain which can be thermally stabilized by other techniques such as alloying in modest degrees and dispersion strengthening. Evaluation of new technology - such as the codeposition of fullerness (diamond-like) particles were made to enhance thermal conductivity in low alloys. A test fire quality tube-bundle engine was fabricated using these copper property improvement concepts to show the superiority of the new coppers and fabrications methods over competitive technologies such as brazing and plasma deposition.

  14. 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.

  15. COPPER RESEARCH UPDATE

    EPA Science Inventory

    This presentation provides an update and overview of new research results and remaining research needs with respect to copper corrosion control issues. The topics to be covered include: occurrence of elevated copper release in systems that meet the Action Level; impact of water c...

  16. Transition-metal doped sulfide, selenide, and telluride laser crystal and lasers

    DOEpatents

    Krupke, W.F.; Page, R.H.; DeLoach, L.D.; Payne, S.A.

    1996-07-30

    A new class of solid state laser crystals and lasers are formed of transition metal doped sulfide, selenide, and telluride host crystals which have four fold coordinated substitutional sites. The host crystals include II-VI compounds. The host crystal is doped with a transition metal laser ion, e.g., chromium, cobalt or iron. In particular, Cr{sup 2+}-doped ZnS and ZnSe generate laser action near 2.3 {micro}m. Oxide, chloride, fluoride, bromide and iodide crystals with similar structures can also be used. Important aspects of these laser materials are the tetrahedral site symmetry of the host crystal, low excited state absorption losses and high luminescence efficiency, and the d{sup 4} and d{sup 6} electronic configurations of the transition metal ions. The same materials are also useful as saturable absorbers for passive Q-switching applications. The laser materials can be used as gain media in amplifiers and oscillators; these gain media can be incorporated into waveguides and semiconductor lasers. 18 figs.

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

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz

    1993-01-01

    The goals of this research were the optimization of growth parameters for large (20 mm diameter and length) zinc selenide single crystals with low structural defect density, and the development of a 3-D numerical model for the transport rates to be expected in physical vapor transport under a given set of thermal and geometrical boundary conditions, in order to provide guidance for an advantageous conduct of the growth experiments. In the crystal growth studies, it was decided to exclusively apply the Effusive Ampoule PVT technique (EAPVT) to the growth of ZnSe. In this technique, the accumulation of transport-limiting gaseous components at the growing crystal is suppressed by continuous effusion to vacuum of part of the vapor contents. This is achieved through calibrated leaks in one of the ground joints of the ampoule. Regarding the PVT transport rates, a 3-D spectral code was modified. After introduction of the proper boundary conditions and subroutines for the composition-dependent transport properties, the code reproduced the experimentally determined transport rates for the two cases with strongest convective flux contributions to within the experimental and numerical error.

  18. Band gap engineering of zinc selenide thin films through alloying with cadmium telluride.

    PubMed

    Al-Kuhaili, M F; Kayani, A; Durrani, S M A; Bakhtiari, I A; Haider, M B

    2013-06-12

    This work investigates band gap engineering of zinc selenide (ZnSe) thin films. This was achieved by mixing ZnSe with cadmium telluride (CdTe). The mass ratio (x) of CdTe in the starting material was varied in the range x = 0-0.333. The films were prepared using thermal evaporation. The chemical composition of the films was investigated through energy dispersive spectroscopy and Rutherford backscattering spectrometry. Structural analysis was carried out using X-ray diffraction and atomic force microscopy. Normal incidence transmittance and reflectance were measured over the wavelength range 300-1300 nm. The absorption coefficients and band gaps were determined from these spectrophotometric measurements. The band gap monotonically decreased from 2.58 eV (for x = 0) to 1.75 eV (for x = 0.333). Photocurrent measurements indicated that the maximum current density was obtained for films with x = 0.286. A figure of merit, based on crystallinity, band gap, and photocurrent, was defined. The optimum characteristics were obtained for the films with x = 0.231, for which the band gap was 2.14 eV. PMID:23688048

  19. Tunable photoconduction sensitivity and bandwidth for lithographically patterned nanocrystalline cadmium selenide nanowires.

    PubMed

    Kung, Sheng-Chin; Xing, Wendong; van der Veer, Wytze E; Yang, Fan; Donavan, Keith C; Cheng, Ming; Hemminger, John C; Penner, Reginald M

    2011-09-27

    Nanocrystalline cadmium selenide (nc-CdSe) nanowires were prepared using the lithographically patterned nanowire electrodeposition method. Arrays of 350 linear nc-CdSe nanowires with lateral dimensions of 60 nm (h) × 200 nm (w) were patterned at 5 ?m pitch on glass. nc-CdSe nanowires electrodeposited from aqueous solutions at 25 °C had a mean grain diameter, d(ave), of 5 nm. A combination of three methods was used to increase d(ave) to 10, 20, and 100 nm: (1) The deposition bath was heated to 75 °C, (2) nanowires were thermally annealed at 300 °C, and (3) nanowires were exposed to methanolic CdCl(2) followed by thermal annealing at 300 °C. The morphology, chemical composition, grain diameter, and photoconductivity of the resulting nanowires were studied as a function of d(ave). As d(ave) was increased from 10 to 100 nm, the photoconductivity response of the nanowires was modified in two ways: First, the measured photoconductive gain, G, was elevated from G = 0.017 (d(ave) = 5 nm) to ?4.9 (100 nm), a factor of 290. Second, the photocurrent rise time was increased from 8 ?s for d(ave) = 10 nm to 8 s for 100 nm, corresponding to a decrease by a factor of 1 million of the photoconduction bandwidth from 44 kHz to 44 mHz. PMID:21861535

  20. 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.

  1. Memory functions of nanocrystalline cadmium selenide embedded ZrHfO high-k dielectric stack

    SciTech Connect

    Lin, Chi-Chou; Kuo, Yue [Thin Film Nano and Microelectronics Research Laboratory, Artie McFerrin Department of Chemical Engineering, Texas A and M University, College Station, Texas 77843-3122 (United States)

    2014-02-28

    Metal-oxide-semiconductor capacitors made of the nanocrystalline cadmium selenide nc-CdSe embedded Zr-doped HfO{sub 2} high-k stack on the p-type silicon wafer have been fabricated and studied for their charge trapping, detrapping, and retention characteristics. Both holes and electrons can be trapped to the nanocrystal-embedded dielectric stack depending on the polarity of the applied gate voltage. With the same magnitude of applied gate voltage, the sample can trap more holes than electrons. A small amount of holes are loosely trapped at the nc-CdSe/high-k interface and the remaining holes are strongly trapped to the bulk nanocrystalline CdSe site. Charges trapped to the nanocrystals caused the Coulomb blockade effect in the leakage current vs. voltage curve, which is not observed in the control sample. The addition of the nanocrystals to the dielectric film changed the defect density and the physical thickness, which are reflected on the leakage current and the breakdown voltage. More than half of the originally trapped holes can be retained in the embedded nanocrystals for more than 10 yr. The nanocrystalline CdSe embedded high-k stack is a useful gate dielectric for this nonvolatile memory device.

  2. Photoluminescence properties of cadmium-selenide quantum dots embedded in a liquid-crystal polymer matrix

    SciTech Connect

    Tselikov, G. I., E-mail: gleb@vega.phys.msu.ru; Timoshenko, V. Yu. [Moscow State University, Faculty of Physics (Russian Federation); Plenge, J.; Ruehl, E. [Free University of Berlin, Institute of Chemistry and Biochemistry (Germany); Shatalova, A. M.; Shandryuk, G. A.; Merekalov, A. S.; Tal'roze, R. V. [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation)

    2013-05-15

    The photoluminescence properties of cadmium-selenide (CdSe) quantum dots with an average size of {approx}3 nm, embedded in a liquid-crystal polymer matrix are studied. It was found that an increase in the quantum-dot concentration results in modification of the intrinsic (exciton) photoluminescence spectrum in the range 500-600 nm and a nonmonotonic change in its intensity. Time-resolved measurements show the biexponential decay of the photoluminescence intensity with various ratios of fast and slow components depending on the quantum-dot concentration. In this case, the characteristic lifetimes of exciton photoluminescence are 5-10 and 35-50 ns for the fast and slow components, respectively, which is much shorter than the times for colloidal CdSe quantum dots of the same size. The observed features of the photoluminescence spectra and kinetics are explained by the effects of light reabsorption, energy transfer from quantum dots to the liquid-crystal polymer matrix, and the effect of the electronic states at the CdSe/(liquid crystal) interface.

  3. Ultrafast charge- and energy-transfer dynamics in conjugated polymer: cadmium selenide nanocrystal blends.

    PubMed

    Morgenstern, Frederik S F; Rao, Akshay; Böhm, Marcus L; Kist, René J P; Vaynzof, Yana; Greenham, Neil C

    2014-02-25

    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

  4. [Bis(pyridin-2-yl) selenide-?2 N,N?]tetra­chloridotin(IV)

    PubMed Central

    Mammadova, Gunay Z.; Matsulevich, Zhanna V.; Osmanov, Vladimir K.; Borisov, Alexander V.; Khrustalev, Victor N.

    2012-01-01

    The title compound, [SnCl4(C10H8N2Se)], was obtained by the reaction of 2,2?-dipyridyl diselenide with tin tetra­chloride. The SnIV ion is coordinated by two N atoms [Sn—N = 2.266?(2) and 2.274?(2)?Å] from the bis­(2-pyrid­yl)selenide ligand and four chloride anions [Sn—Cl = 2.3717?(6)–2.3939?(6)?Å] in a distorted octa­hedral geometry. The central six-membered chelate ring has a boat conformation with the Se and Sn atoms deviating by 0.692?(3) and 0.855?(3)?Å, respectively, from the mean plane through the remaining four ring atoms. The pyridine rings are inclined to each other by a dihedral angle of 49.62?(8)°. The crystal packing exhibits short inter­molecular Se?Cl contacts [3.5417?(7) and 3.5648?(7)?Å], weak C—H?Cl hydrogen bonds and ?–? stacking inter­actions between the pyridine rings with a centroid–centroid distance of 3.683?(3)?Å. PMID:22807800

  5. [Bis(pyridin-2-yl) selenide-?(2)N,N']tetra-chloridotin(IV).

    PubMed

    Mammadova, Gunay Z; Matsulevich, Zhanna V; Osmanov, Vladimir K; Borisov, Alexander V; Khrustalev, Victor N

    2012-07-01

    The title compound, [SnCl(4)(C(10)H(8)N(2)Se)], was obtained by the reaction of 2,2'-dipyridyl diselenide with tin tetra-chloride. The Sn(IV) ion is coordinated by two N atoms [Sn-N = 2.266?(2) and 2.274?(2)?Å] from the bis-(2-pyrid-yl)selenide ligand and four chloride anions [Sn-Cl = 2.3717?(6)-2.3939?(6)?Å] in a distorted octa-hedral geometry. The central six-membered chelate ring has a boat conformation with the Se and Sn atoms deviating by 0.692?(3) and 0.855?(3)?Å, respectively, from the mean plane through the remaining four ring atoms. The pyridine rings are inclined to each other by a dihedral angle of 49.62?(8)°. The crystal packing exhibits short inter-molecular Se?Cl contacts [3.5417?(7) and 3.5648?(7)?Å], weak C-H?Cl hydrogen bonds and ?-? stacking inter-actions between the pyridine rings with a centroid-centroid distance of 3.683?(3)?Å. PMID:22807800

  6. Poole-Frenkel conduction in antimony-doped tin selenide thin films

    NASA Astrophysics Data System (ADS)

    Sakrani, S. B.; Jabar, Sakena A.

    1998-02-01

    Tin selenide thin films have been prepared onto glass substrates at a temperature 240 degrees Celsius and fixed film thickness by means of a solid state reaction process at pressure about 10-5 mbar. Low level antimony doping was maintained at a concentration 1.8%. The dark current- voltage measurements have been performed on the sandwiched structures of Al-SnSe-Al and Al-SnSe:Sb-Al at temperatures in the range 143 - 300 K, and the results showed a ln J varies direct as V1/2 dependence which was indicative of the Poole-Frenkel effect. It was found that, the calculated field-lowering coefficients, (beta) p for the latter samples (3.71 - 4.81 X 10-5 eV m1/2 V-1/2) were higher than the predicted value (2.18 X 10-5 eV m1/2 V-1/2) by a factor of 1.71 - 2.21. These were further confirmed by the linear dependence of the graphs's slope and inverse of temperature. The results were explained in terms of lowering potential barrier by the interaction of electron with applied electric field.

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

    NASA Astrophysics Data System (ADS)

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

    2003-05-01

    The versatile spray pyrolysis technique was employed to prepare thin films of lanthanum selenide (La 2Se 3) 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 La 2Se 3 phase. The estimated optical band gap was found to be 2.6 eV. The dielectric properties such as dielectric constant and dielectric loss of the films deposited on FTO coated glass substrates were measured with FTO-La 2Se 3-Ag structure as a function of frequency and the results are reported. At room temperature dielectric constant and dielectric loss for 1 kHz frequency were found to be 6.2 and 0.048, respectively. The room temperature electrical resistivity was of the order of 10 5 ? cm. The La 2Se 3 films are found to be n-type semiconductor.

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

    NASA Astrophysics Data System (ADS)

    Gupta, Vinay; Upreti, Tanvi; Chand, Suresh

    2013-12-01

    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(FBTTh2)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(FBTTh2)2: CdSe/Ca/Al. The optimized ratio of p-DTS(FBTTh2)2:CdSe::60:40 leads to a short circuit current density (Jsc) = 5.45 mA/cm2, open circuit voltage (Voc) = 0.727 V, and fill factor (FF) = 51%, and a power conversion efficiency = 2.02% at 100 mW/cm2 under AM1.5G illumination. The Jsc and FF are sensitive to the ratio of p-DTS(FBTTh2)2:CdSe, which is a crucial factor for the device performance.

  9. 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.

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

    PubMed Central

    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

  11. 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

  12. Transition-metal doped sulfide, selenide, and telluride laser crystal and lasers

    DOEpatents

    Krupke, William F. (Pleasanton, CA); Page, Ralph H. (San Ramon, CA); DeLoach, Laura D. (Manteca, CA); Payne, Stephen A. (Castro Valley, CA)

    1996-01-01

    A new class of solid state laser crystals and lasers are formed of transition metal doped sulfide, selenide, and telluride host crystals which have four fold coordinated substitutional sites. The host crystals include II-VI compounds. The host crystal is doped with a transition metal laser ion, e.g., chromium, cobalt or iron. In particular, Cr.sup.2+ -doped ZnS and ZnSe generate laser action near 2.3 .mu.m. Oxide, chloride, fluoride, bromide and iodide crystals with similar structures can also be used. Important aspects of these laser materials are the tetrahedral site symmetry of the host crystal, low excited state absorption losses and high luminescence efficiency, and the d.sup.4 and d.sup.6 electronic configurations of the transition metal ions. The same materials are also useful as saturable absorbers for passive Q-switching applications. The laser materials can be used as gain media in amplifiers and oscillators; these gain media can be incorporated into waveguides and semiconductor lasers.

  13. The piezoresistance coefficients of copper and copper-nickel alloys

    Microsoft Academic Search

    Changyi Hu; Yiqun Gao; Zhongyi Sheng

    2000-01-01

    This paper attempts to further a better understanding of the piezoresistance coefficients by studying the piezoresistive effects in copper and copper-nickel alloys. The experimental evidence of isotropic piezoresistance coefficients (p11?=?p12) has been obtained for the annealed copper and copper-nickel alloys. The piezoresistance coefficients of the cold-worked copper and Cu60Ni40 alloy are of the tensor character (p11???p12). A physical explanation has

  14. Copper tolerance in Silene cucubalus

    Microsoft Academic Search

    P. C. Lolkema; R. Vooijs

    1986-01-01

    The uptake, translocation and subcellular distribution of copper as well as its effect on chloroplasts and plastocyanin synthesis were studied in a copper-sensitive and a copper-tolerant population of Silene cucubalus (L.) Wib. As a function of time, the copper concentration in roots of tolerant plants increased more slowly than that in roots of sensitive ones. Translocation to the shoot occurred

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. Drinking Water Problems: Copper

    E-print Network

    Dozier, Monty; McFarland, Mark L.; Lesikar, Bruce J.

    2006-01-25

    Monty C. Dozier, Assistant Professor and Extension Specialist, Mark McFarland, Professor and Extension Soil Fertlity Specialist, Bruce J. Lesikar, Professor and Extension Agricultural Engineer, Texas Cooperative Extension, The Texas A&M University... of electrical currents. Proper testing of the water and diagnosis of the cause of elevated copper concentrations in the water are essential to identify a treatment system that will control or correct the problem. What are the indications of copper present...

  20. Copper tolerance and copper accumulation of herbaceous plants colonizing inactive California copper mines

    SciTech Connect

    Kruckeberg, A.L.; Wu, L. (Department of Environmental Horticulture, University of California, Davis (United States))

    1992-06-01

    Herbaceous plant species colonizing four copper mine waste sites in northern California were investigated for copper tolerance and copper accumulation. Copper tolerance was found in plant species colonizing soils with high concentrations of soil copper. Seven of the eight plant species tested were found at more than one copper mine. The mines are geographically isolated, which makes dispersal of seeds from one mine to another unlikely. Tolerance has probably evolved independently at each site. The nontolerant field control population of Vulpia microstachya displays significantly higher tolerance to copper at all copper concentration levels tested than the nontolerant Vulpia myrous population, and the degree of copper tolerance attained by V. microstachya at the two copper mines was much greater than that found in V. myrous. It suggests that even in these two closely related species, the innate tolerance in their nontolerant populations may reflect their potential for evolution of copper tolerance and their ability to initially colonize copper mine waste sites. The shoot tissue of the copper mine plants of Arenaria douglasii, Bromous mollis, and V. microstachya accumulated less copper than those plants of the same species from the field control sites when the two were grown in identical conditions in nutrient solution containing copper. The root tissue of these mine plants contain more copper than the roots of the nonmine plants. This result suggests that exclusion of copper from the shoots, in part by immobilization in the roots, may be a feature of copper tolerance. No difference in the tissue copper concentration was detected between tolerant and nontolerant plants of Lotus purshianus, Lupinus bicolor, and Trifolium pratense even though the root tissue had more copper than the leaves.

  1. Entrainment behavior of copper and copper matte in copper smelting operations

    Microsoft Academic Search

    S. W. Ip; J. M. Toguri

    1992-01-01

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

  2. Mott metal-insulator transitions in d-electron (hole) Degenerate transition metal oxides, sulphides and selenides

    Microsoft Academic Search

    Edward Siegel

    1978-01-01

    The phase diagrams o fthe Mott metal-insulator transition of Kohn, Rice and Brinkman, Gutzwiller, Goodenough and McWhan et al. are modified by the inclusion of d-electron (hole) spin-orbital degeneracy along the lines of the ren-fold degenerate Hubbard and Anderson models of Siegel and Kemeny, and Moriya. The systems treated are: transition metal sulphides and selenides (NiS2,NiSe2, CoSe2, RhSe2etc.), the transition

  3. 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...CERTIFICATION Drugs § 73.1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper...Identity. (1) The color additive potassium sodium copper chlorophyllin is...

  4. Parallel molecular dynamics simulations of pressure-induced structural transformations in cadmium selenide nanocrystals

    NASA Astrophysics Data System (ADS)

    Lee, Nicholas Jabari Ouma

    Parallel molecular dynamics (MD) simulations are performed to investigate pressure-induced solid-to-solid structural phase transformations in cadmium selenide (CdSe) nanorods. The effects of the size and shape of nanorods on different aspects of structural phase transformations are studied. Simulations are based on interatomic potentials validated extensively by experiments. Simulations range from 105 to 106 atoms. These simulations are enabled by highly scalable algorithms executed on massively parallel Beowulf computing architectures. Pressure-induced structural transformations are studied using a hydrostatic pressure medium simulated by atoms interacting via Lennard-Jones potential. Four single-crystal CdSe nanorods, each 44A in diameter but varying in length, in the range between 44A and 600A, are studied independently in two sets of simulations. The first simulation is the downstroke simulation, where each rod is embedded in the pressure medium and subjected to increasing pressure during which it undergoes a forward transformation from a 4-fold coordinated wurtzite (WZ) crystal structure to a 6-fold coordinated rocksalt (RS) crystal structure. In the second so-called upstroke simulation, the pressure on the rods is decreased and a reverse transformation from 6-fold RS to a 4-fold coordinated phase is observed. The transformation pressure in the forward transformation depends on the nanorod size, with longer rods transforming at lower pressures close to the bulk transformation pressure. Spatially-resolved structural analyses, including pair-distributions, atomic-coordinations and bond-angle distributions, indicate nucleation begins at the surface of nanorods and spreads inward. The transformation results in a single RS domain, in agreement with experiments. The microscopic mechanism for transformation is observed to be the same as for bulk CdSe. A nanorod size dependency is also found in reverse structural transformations, with longer nanorods transforming more readily than smaller ones. Nucleation initiates at the center of the rod and grows outward.

  5. Phase selection and site-selective distribution by tin and sulfur in supertetrahedral zinc gallium selenides.

    PubMed

    Wu, Tao; Bu, Xianhui; Zhao, Xiang; Khazhakyan, Ripsime; Feng, Pingyun

    2011-06-22

    Doping is among the most important methods to tune the properties of semiconductors. For dense phase semiconductors, the distribution of dopant atoms in crystal lattices is often random. However, when the size of semiconductors becomes increasingly smaller and reaches the extreme situation as is the case in chalcogenide supertetrahedral clusters, different chemically distinct sites (e.g., corner, edge, face, and core) occur, which can dramatically affect the doping chemistry at different sites and also spatial assembly of such clusters into covalent superlattices. In this work, we use the Zn-Ga-Se supertetrahedral clusters and their frameworks as the model system to examine the doping chemistry of Sn(4+) and S(2-) in the Zn-Ga-Se clusters. A series of selenide clusters (undoped supertetrahedral T4-ZnGaSe, S-doped T4-ZnGaSeS, Sn-doped T4-ZnGaSnSe, and dual S- and Sn-doped T4-ZnGaSnSeS) have been prepared with various levels of Sn- and S-doping and with different superlattice structures (OCF-1, -5, -40, and -42). The complex compositional and structural features of these materials are dictated by the convoluted interplay of three key factors: (1) the overall charge density and size/shape matching between clusters/frameworks and protonated guest amines determine the framework topology and the doping levels of Sn(4+) and S(2-); (2) the site selectivity of Sn(4+) is dictated by the local charge balance surrounding anionic Se/S sites as required by the electrostatic valence sum rule; and (3) the site selectivity and doping levels of sulfur is dictated by the location and amount of Sn based on hard soft acid base (HSAB) principle. The cooperative effect of amine-templating and doping by Sn and/or S leads to a rich chemical system with tunable framework compositions, topologies, and electronic properties. PMID:21595469

  6. 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

  7. Phase diagram of (Li(1-x)Fe(x))OHFeSe: a bridge between iron selenide and arsenide superconductors.

    PubMed

    Dong, Xiaoli; Zhou, Huaxue; Yang, Huaixin; Yuan, Jie; Jin, Kui; Zhou, Fang; Yuan, Dongna; Wei, Linlin; Li, Jianqi; Wang, Xinqiang; Zhang, Guangming; Zhao, Zhongxian

    2015-01-14

    Previous experimental results have shown important differences between iron selenide and arsenide superconductors which seem to suggest that the high-temperature superconductivity in these two subgroups of iron-based families may arise from different electronic ground states. Here we report the complete phase diagram of a newly synthesized superconducting (SC) system, (Li1-xFex)OHFeSe, with a structure similar to that of FeAs-based superconductors. In the non-SC samples, an antiferromagnetic (AFM) spin-density-wave (SDW) transition occurs at ?127 K. This is the first example to demonstrate such an SDW phase in an FeSe-based superconductor system. Transmission electron microscopy shows that a well-known ?5×?5 iron vacancy ordered state, resulting in an AFM order at ?500 K in AyFe2-xSe2 (A = metal ions) superconductor systems, is absent in both non-SC and SC samples, but a unique superstructure with a modulation wave vector q = (1)/2(1,1,0), identical to that seen in the SC phase of KyFe2-xSe2, is dominant in the optimal SC sample (with an SC transition temperature Tc = 40 K). Hence, we conclude that the high-Tc superconductivity in (Li1-xFex)OHFeSe stems from the similarly weak AFM fluctuations as FeAs-based superconductors, suggesting a universal physical picture for both iron selenide and arsenide superconductors. PMID:25532066

  8. Growth and evaluation of nonlinear optical crystals for laser applications: Lithium borate, barium borate and silver gallium selenide

    NASA Astrophysics Data System (ADS)

    Feigelson, Robert S.; Route, Roger K.

    1994-12-01

    This report summarizes a four year program on the development of high efficiency nonlinear optical materials. Major achievements were the development of effective top-seeded solution growth techniques for beta-barium borate (BBO) and lithium triborate (LBO). BBO crystals were also grown for the first time in the US by the direct melt growth technique, a metastable method that leads to significantly higher growth rates than the commercial solution-growth technique. High quality crystals were made available for optical property determinations and nonlinear optical device development at government and commercial laboratories. Additional accomplishments involved development of an optimum heat-treatment technology for eliminating optical scattering centers from as-grown crystals of silver gallium selenide. Cooperative programs were carried out with NRL to quantify the effects of intrinsic and extrinsic defects on residual absorption. It was discovered that silver gallium selenide and silver gallium sulfide crystals grown from silver-rich solutions are free of anomolous absorption in the 2 micron waveband which is currently the major problem limiting generation of high intensity, tunable 3-5 micron radiation by OPO methods using these materials. A new nonlinear optical material, (La,Gd)Sc3(BO3)4 has been identified for future study.

  9. Copper trafficking to the mitochondrion and assembly of copper metalloenzymes

    Microsoft Academic Search

    Paul A. Cobine; Fabien Pierrel; Dennis R. Winge

    2006-01-01

    Copper is required within the mitochondrion for the function of two metalloenzymes, cytochrome c oxidase (CcO) and superoxide dismutase (Sod1). Copper metallation of these two enzymes occurs within the mitochondrial intermembrane space and is mediated by metallochaperone proteins. Cox17 is a key copper donor to two accessory proteins, Sco1 and Cox11, to form the two copper centers in the mature

  10. Copper Proteins and Oxygen

    PubMed Central

    Frieden, Earl; Osaki, Shigemasa; Kobayashi, Hiroshi

    1965-01-01

    A comprehensive survey of the interaction of the copper proteins and oxygen is presented including a correlation of structure, function, and other properties of the known copper oxidases and of hemocyanin. The origin of their blue color and the structure of copper complexes and copper proteins are related to the oxidation state of copper ion and relevant electronic transitions probably arising from the formation of charge transfer complexes. The oxygen reactions of hemocyanin, ceruloplasmin, and cytochrome oxidase show half-saturation values far below the other Cu enzymes. The formation of hydrogen peroxide as a reaction product is associated with the presence of one Cu atom per oxidase molecule or catalytic system. Water is the corresponding product of the other Cu oxidases with four or more Cu atoms per molecule, except for monoamine oxidase. Mechanisms for the oxidase action of the two and four electron transfer Cu oxidases and tyrosinase are proposed. These reactions account for the number, the oxidation-reduction potential, and the oxidation state of Cu in the resting enzyme, the cyclical change from Cu(II) to Cu(I), the diatomic nature of O2, the sequence of the oxidation and reduction reactions, and other salient features. The catalytic reactions involved in the oxidation of ascorbic acid by plant ascorbate oxidase, ceruloplasmin, and Cu(II) are compared. Finally the substrate specificity, inhibitory control, and the detailed mechanism of the oxidase activity of ceruloplasmin are summarized. PMID:4285728

  11. Soft Chemical Control of Superconductivity in Lithium Iron Selenide Hydroxides Li1-xFex(OH)Fe1-ySe.

    PubMed

    Sun, Hualei; Woodruff, Daniel N; Cassidy, Simon J; Allcroft, Genevieve M; Sedlmaier, Stefan J; Thompson, Amber L; Bingham, Paul A; Forder, Susan D; Cartenet, Simon; Mary, Nicolas; Ramos, Silvia; Foronda, Francesca R; Williams, Benjamin H; Li, Xiaodong; Blundell, Stephen J; Clarke, Simon J

    2015-02-16

    Hydrothermal synthesis is described of layered lithium iron selenide hydroxides Li1-xFex(OH)Fe1-ySe (x ? 0.2; 0.02 < y < 0.15) with a wide range of iron site vacancy concentrations in the iron selenide layers. This iron vacancy concentration is revealed as the only significant compositional variable and as the key parameter controlling the crystal structure and the electronic properties. Single crystal X-ray diffraction, neutron powder diffraction, and X-ray absorption spectroscopy measurements are used to demonstrate that superconductivity at temperatures as high as 40 K is observed in the hydrothermally synthesized samples when the iron vacancy concentration is low (y < 0.05) and when the iron oxidation state is reduced slightly below +2, while samples with a higher vacancy concentration and a correspondingly higher iron oxidation state are not superconducting. The importance of combining a low iron oxidation state with a low vacancy concentration in the iron selenide layers is emphasized by the demonstration that reductive postsynthetic lithiation of the samples turns on superconductivity with critical temperatures exceeding 40 K by displacing iron atoms from the Li1-xFex(OH) reservoir layer to fill vacancies in the selenide layer. PMID:25613347

  12. Copper and copper-nickel alloys as zebra mussel antifoulants

    SciTech Connect

    Dormon, J.M.; Cottrell, C.M.; Allen, D.G.; Ackerman, J.D.; Spelt, J.K. [Univ. of Toronto, Ontario (Canada)

    1996-04-01

    Copper has been used in the marine environment for decades as cladding on ships and pipes to prevent biofouling by marine mussels (Mytilus edulis L.). This motivated the present investigation into the possibility of using copper to prevent biofouling in freshwater by both zebra mussels and quagga mussels (Dreissena polymorpha and D. bugensis collectively referred to as zebra mussels). Copper and copper alloy sheet proved to be highly effective in preventing biofouling by zebra mussels over a three-year period. Further studies were conducted with copper and copper-nickel mesh (lattice of expanded metal) and screen (woven wire with a smaller hole size), which reduced the amount of copper used. Copper screen was also found to be strongly biofouling-resistant with respect to zebra mussels, while copper mesh reduced zebra mussel biofouling in comparison to controls, but did not prevent it entirely. Preliminary investigations into the mechanism of copper antifouling, using galvanic couples, indicated that the release of copper ions from the surface of the exposed metal into the surrounding water is directly or indirectly responsible for the biofouling resistance of copper.

  13. Preparation of high purity copper fluoride by fluorinating copper hydroxyfluoride

    NASA Technical Reports Server (NTRS)

    King, R. B.; Lundquist, J. R.

    1969-01-01

    Copper fluoride containing no more than 50 ppm of any contaminating element was prepared by the fluorination of copper hydroxyfluoride. The impurity content was obtained by spark source mass spectrometry. High purity copper fluoride is needed as a cathode material for high energy density batteries.

  14. 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

  15. Copper and copper-nickel alloys as zebra mussel antifoulants

    Microsoft Academic Search

    Jane M. Dormon; Catherine M. Cottrell; D. Grant Allen; Joseph D. Ackerman; Jan K. Spelt

    1996-01-01

    Copper has been used in the marine environment for decades as cladding on ships and pipes to prevent biofouling by marine mussels (Mytilus edulis L.). This motivated the present investigation into the possibility of using copper to prevent biofouling in freshwater by both zebra mussels and quagga mussels (Dreissena polymorpha and D. bugensis collectively referred to as zebra mussels). Copper

  16. Exploring for Copper Deposits

    NSDL National Science Digital Library

    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.

  17. Copper-phosphorus alloys offer advantages in brazing copper

    SciTech Connect

    Rupert, W.D. [Engelhard Corp., Warwick, RI (United States)

    1996-05-01

    Copper-phosphorus brazing alloys are used extensively for joining copper, especially refrigeration and air-conditioning copper tubing and electrical conductors. What is the effect of phosphorus when alloyed with copper? The following are some of the major effects: (1) It lowers the melt temperature of copper (a temperature depressant). (2) It increases the fluidity of the copper when in the liquid state. (3) It acts as a deoxidant or a fluxing agent with copper. (4) It lowers the ductility of copper (embrittles). There is a misconception that silver improves the ductility of the copper-phosphorus alloys. In reality, silver added to copper acts in a similar manner as phosphorus. The addition of silver to copper lowers the melt temperature (temperature depressant) and decreases the ductility. Fortunately, the rate and amount at which silver lowers copper ductility is significantly less than that of phosphorus. Therefore, taking advantage of the temperature depressant property of silver, a Ag-Cu-P alloy can be selected at approximately the same melt temperature as a Cu-P alloy, but at a lower phosphorus content. The lowering of the phosphorus content actually makes the alloy more ductile, not the silver addition. A major advantage of the copper-phosphorus alloys is the self-fluxing characteristic when joining copper to copper. They may also be used with the addition of a paste flux on brass, bronze, and specialized applications on silver, tungsten and molybdenum. Whether it is selection of the proper BCuP alloy or troubleshooting an existing problem, the suggested approach is a review of the desired phosphorus content in the liquid metal and how it is being altered during application. In torch brazing, a slight change in the oxygen-fuel ratio can affect the joint quality or leak tightness.

  18. High adherence copper plating process

    SciTech Connect

    Mignardot, H.

    1992-12-31

    A process is described 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.

  19. High adherence copper plating process

    DOEpatents

    Nignardot, H.

    1993-09-21

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

  20. December 200 Copper Acquisition by

    E-print Network

    Fischlin, Andreas

    December 200 Copper Acquisition by Methanotrophic Bacteria 7 Term Paper HS2007 Major a specific copper acquisition strategy. In recent stu- dies, an enzyme extruded by some microorganisms which but also has a high affinity to other metals. Our current knowledge on copper acquisition of methano

  1. Copper leaching from chalcopyrite concentrates

    NASA Astrophysics Data System (ADS)

    Wang, Shijie

    2005-07-01

    Chalcopyrite (CuFeS2) is one of the most abundant copper-bearing minerals, which accounts for approximately 70 percent of the world’s known copper reserves. For more than 30 years, a significant number of processes have been developed to leach copper from chalcopyrite concentrates. These processes recover copper via hydrometallurgical leaching of the copper component of chalcopyrite concentrates, followed by solvent extraction and electrowinning. A number of demonstration plant operations have been conducted, but as of this writing none of the processes have become completely commercially operational.

  2. Type Zero Copper Proteins

    PubMed Central

    Lancaster, Kyle M.; DeBeer George, Serena; Yokoyama, Keiko; Richards, John H.; Gray, Harry B.

    2009-01-01

    Copper proteins play key roles in biological processes such as electron transfer and dioxygen activation; the active site of each of these proteins is classified as either type 1, 2, or 3, depending on its optical and electron paramagnetic resonance properties. We have built a new type of site that we call “type zero copper” by incorporating leucine, isoleucine, or phenylalanine in place of methionine at position 121 in C112D Pseudomonas aeruginosa azurin. X-ray crystallographic analysis shows that these sites adopt distorted tetrahedral geometries, with an unusually short Cu-O(G45 carbonyl) bond (2.35–2.55 Å). Relatively weak absorption near 800 nm and narrow parallel hyperfine splittings in EPR spectra are the spectroscopic signatures of type zero copper. Copper K-edge x-ray absorption spectra suggest elevated Cu(II) 4p character in the d-electron ground state. Cyclic voltammetric experiments demonstrate that the electron transfer reactivities of type zero azurins are enhanced relative to that of the corresponding type 2 (C112D) protein. PMID:20305734

  3. 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.…

  4. 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.

  5. Supersonic copper clusters

    NASA Astrophysics Data System (ADS)

    Powers, D. E.; Hansen, S. G.; Geusic, M. E.; Michalopoulos, D. L.; Smalley, R. E.

    1983-03-01

    Copper clusters ranging in size from 1 to 29 atoms have been prepared in a supersonic beam by laser vaporization of a rotating copper target rod within the throat of a pulsed supersonic nozzle using helium for the carrier gas. The clusters were cooled extensively in the supersonic expansion [T(translational) 1 to 4 K, T(rotational)=4 K, T(vibrational)=20 to 70 K]. These clusters were detected in the supersonic beam by laser photoionization with time-of-flight mass analysis. Using a number of fixed frequency outputs of an exciplex laser, the threshold behavior of the photoionization cross section was monitored as a function of cluster size. The 7.9 eV photon energy of the F2 excimer laser was found to be above the ionization potential of all clusters, and the photoion mass spectrum thus produced showed the copper cluster concentration in the beam to follow a monotonically decreasing function of cluster size. The 6.4 eV ArF exciplex laser photon energy was found to be above the photoionization threshold of clusters with three or more atoms in the case of odd-numbered clusters, but only for clusters with eight or more atoms for even-numbered clusters. Extending out to clusters as large as 29 atoms, laser photoionization at 6.4 eV produced a time-of-flight mass distribution with a pronounced even/odd alternation in cluster photoion intensity. This alternation in ionization threshold behavior was attributed to an even/odd alternation in the electronic structure of the copper clusters with the highest occupied molecular orbital (HOMO) of the even clusters being considerably more strongly bonding than it is in the clusters with an odd number of copper atoms. The 4.98 eV photon energy of the KrF exciplex laser was found to lie below the ionization threshold of all clusters in the 1 to 29 atom range. An extensive survey of the ultraviolet absorption spectrum of the copper dimer was also performed with this supersonic beam source. Resonance two-photon ionization (R2PI) with mass selective detection allowed the detection of five new electronic band systems in the region between 2690 and 3200 Å, for each of the three naturally occurring isotopic forms of Cu2. In the process of scanning the R2PI spectrum of these new electronic states, the ionization potential of the copper dimer was determined to be 7.894±0.015 eV.

  6. Volume 7. Copper base powder metallurgy

    Microsoft Academic Search

    Taubenblat

    1980-01-01

    This book is based on a series of lectures on copper and copper base P\\/M materials sponsored by the Metal Powder Industries Federation. It covers recent developments in the fields of copper powder metallurgy and offers a comprehensive survey of copper and copper-base P\\/M materials. It begins with a chapter on the production of copper and copper alloy powders followed

  7. Synthesis and characterization of the layered iron-selenide Na0.8Fe1.6Se2

    NASA Astrophysics Data System (ADS)

    Long, Y. J.; Wang, D. M.; Wang, Z.; Yang, H. X.; He, J. B.; Zhao, L. X.; Wang, P. P.; Xue, M. Q.; Li, J. Q.; Ren, Z. A.; Chen, G. F.

    2014-10-01

    An iron-selenide Na0.8Fe1.6Se2 single crystal has been successfully synthesized using a self-flux method. The electrical resistivity measurement shows that this material exhibits semiconducting behavior in the whole temperature range, with an anomalous increment of resistivity at Ts˜595 K. By varying the concentrations of Na and Fe, a small volume of superconducting phase could be achieved with a critical temperature of Tc˜34 K. Structural characterization shows that, similarly to K0.8Fe1.6Se2 , the Na0.8Fe1.6Se2 phase exhibits clear superstructure with a modulation wave vector of q =(3 /5 ,1 /5 ,0 ) caused by the Fe-vacancy order within the a-b plane.

  8. Enhancement in hole current density on polarization in poly(3-hexylthiophene):cadmium selenide quantum dot nanocomposite thin films

    NASA Astrophysics Data System (ADS)

    Kumari, Kusum; Chand, Suresh; Vankar, V. D.; Kumar, Vikram

    2009-05-01

    We demonstrate the effect of polarization on space charge limited J-V behavior in poly(3-hexylthiophene) (P3HT):cadmium selenide (CdSe) (˜5 nm) quantum dot nanocomposite thin films in hole-only device configuration, indium tin oxide/poly(ethylene-dioxthiophene):polystyrenesulphonate/P3HT:CdSe/Au. Current density has been found to enhance in these hybrid films on polarization. This has been attributed to decrease in characteristic trap energy from 32 to 27 meV, trap density from 1.7×1018 to 1×1018 cm-3 and increase in hole mobility from 2.6×10-6 to 7.7×10-6 cm2 V-1 s-1 due to field induced enhanced order by dipolar alignment and/or trapping of charge carriers at the nanoscale interfacial boundaries of P3HT and CdSe quantum dots.

  9. Crystal growth and magnetic properties of tin selenide-doped europium Sn 1-xEu xSe

    NASA Astrophysics Data System (ADS)

    Isber, S.; Gratens, X.

    2010-05-01

    The growth and magnetic properties of Tin Selenide (SnSe) doped with Eu 2+ Sn 1-xEu xSe ( x=2.5%) were investigated. Q-band (34 GHz) electron paramagnetic resonance measurements show that the site symmetry of Eu 2+ at 4.2 K is orthorhombic and the Landé factor was determined to be g=1.99±0.01. The exchange coupling between nearest-neighbor (NN) Eu 2+ ions was estimated from magnetization and magnetic-susceptibility measurements using a model that takes into account the magnetic contributions of single ions, pairs and triplets. The exchange interaction between Eu 2+ nearest neighbors was found to be antiferromagnetic with an estimated average value of J p/ k B=-0.18±0.03 K.

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. Copper isotope fractionation in sedimentary copper mineralization (Timna Valley, Israel)

    Microsoft Academic Search

    Dan Asael; Alan Matthews; Miryam Bar-Matthews; Ludwik Halicz

    2007-01-01

    Copper isotopes (65Cu\\/63Cu) are potentially powerful new geochemical proxies for oxidation–reduction processes and metallic cycling. This research presents a Cu-isotope study of mineralization in historically mined stratiform sediment-hosted copper (SSC) ore deposits of the Precambrian and Cambrian rocks of the Timna Valley, southern Israel. These deposits provide a natural laboratory for studying isotopic fractionations between Cu-sulphides and Cu(II) minerals (copper

  15. Selective oxidation of copper from liquid copper-silver alloys

    Microsoft Academic Search

    C. A. Pickles

    1998-01-01

    In this work, the oxygen refining of liquid copper-silver alloys with a borosilicate slag was studied. First, a comprehensive\\u000a thermodynamic analysis was performed using the data available in the literature. The results indicate that since silver oxide\\u000a is relatively unstable in silicate-based slags, then it should be thermodynamically feasible to oxidize copper from copper-silver\\u000a alloys with a very low silver

  16. Oxidation rates of liquid copper and liquid copper sulfide

    Microsoft Academic Search

    F. Ajersch; J. M. Toguri

    1972-01-01

    The kinetics of oxidation of liquid copper and copper sulfide were determined when the rate was controlled by the diffusion\\u000a of the oxidizing gas to the melt interface. The method incorporated a capillary tube sample holder and the flux rate was measured\\u000a by a quartz spring and cathetometer. The sample of copper sulfide was suspended from the balance in a

  17. Friction stir welding of copper and copper alloys

    Microsoft Academic Search

    K. Nakata

    2005-01-01

    Copper, through having good thermal conductivity and a relatively high melting point, generally requires preheating treatment to maintain satisfactory penetration during arc welding, ranking as a hard-to-weld material. Like aluminium and magnesium, however, copper is basically a soft metal and can therefore be relatively easily joined by friction stir welding. Available FSW research has focused on fabrication of copper (oxygen-free

  18. Copper@polypyrrole nanocables

    PubMed Central

    2012-01-01

    A simple hydrothermal redox reaction between microcrystalline CuOHCl and pyrrole leads to the isolation of striking nanostructures formed by polypyrrole-coated copper nanocables. These multicomponent cables that feature single-crystalline face-centered cubic Cu cores (ca. 300 nm wide and up to 200 ?m long) are smoothly coated by conducting polypyrrole, which in addition to its functionality, offers protection against oxidation of the metal core. PMID:23009710

  19. Copper losses and thermodynamic considerations in copper smelting

    Microsoft Academic Search

    R. Sridhar; J. M. Toguri; S. Simeonov

    1997-01-01

    A relationship between copper in slag and copper in matte during copper sulfide smelting has been derived using industrial\\u000a data from 42 plants employing blast furnaces, reverberatory furnaces, flash furnaces, and Mitsubishi smelting furnaces together\\u000a with the available thermodynamic equilibrium data for Cu-Fe-S-O, FeO-SiO2, and Cu-Fe-S systems and laboratory slag-matte equilibrium information. A copper smelting diagram showing oxygen potential;\\u000a sulfur

  20. Structure and composition of the superconducting phase in alkali iron selenide KyFe1.6+xSe2

    NASA Astrophysics Data System (ADS)

    Carr, Scott V.; Louca, Despina; Siewenie, Joan; Huang, Q.; Wang, Aifeng; Chen, Xianhui; Dai, Pengcheng

    2014-04-01

    We use neutron diffraction to study the temperature evolution of the average structure and local lattice distortions in insulating and superconducting potassium iron selenide KyFe1.6+xSe2. In the high temperature paramagnetic state, both materials have a single phase with a crystal structure similar to that of the BaFe2As2 family of iron pnictides. While the insulating KyFe1.6+xSe2 forms a ?5 ×?5 iron vacancy ordered block antiferromagnetic (AF) structure at low temperature, the superconducting compounds spontaneously phase separate into an insulating part with ?5 ×?5 iron vacancy order and a superconducting phase with chemical composition of KzFe2Se2 and BaFe2As2 structure. Therefore, superconductivity in alkaline iron selenides arises from alkali deficient KzFe2Se2 in the matrix of the insulating block AF phase.

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. 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

  6. Entrainment behavior of copper and copper matte in copper smelting operations

    NASA Astrophysics Data System (ADS)

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

    1992-06-01

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

  7. Synthesis of copper/copper oxide nanoparticles by solution plasma

    NASA Astrophysics Data System (ADS)

    Saito, Genki; Hosokai, Sou; Tsubota, Masakatsu; Akiyama, Tomohiro

    2011-07-01

    This paper describes the synthesis of copper/copper oxide nanoparticles via a solution plasma, in which the effect of the electrolyte and electrolysis time on the morphology of the products was mainly examined. In the experiments, a copper wire as a cathode was immersed in an electrolysis solution of a K2CO3 with the concentration from 0.001 to 0.50 M or a citrate buffer (pH = 4.8), and was melted by the local-concentration of current. The results demonstrated that by using the K2CO3 solution, we obtained CuO nanoflowers with many sharp nanorods, the size of which decreased with decreasing the concentration of the solution. Spherical particles of copper with/without pores formed when the citrate buffer was used. The pores in the copper nanoparticles appeared when the applied voltage changed from 105 V to 130 V, due to the dissolution of Cu2O.

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

    SciTech Connect

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

    1995-12-31

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

  9. AN OVERVIEW OF PROCESS OPTIONS AND BEHAVIORAL ASPECTS OF THE COPPER VALUES RECOVERED FROM THE COPPER BLEED STREAM OF A COPPER SMELTER DEVELOPED AT THE NATIONAL METALLURGICAL LABORATORY

    Microsoft Academic Search

    Archana Agrawal; D. Bagchi; S. Kumari; B. D. Pandey

    2009-01-01

    In the present research, an effort has been made to prepare copper salt\\/powder from the copper bleed stream generated during the electrowinning of pure copper from the copper anode in a copper smelter. Various approaches have been opted for the complete recovery of copper values such as: evaporation–crystallization, electrolytic process, and direct hydrogen reduction. Physical and chemical properties of copper

  10. Flame spectra of copper salts

    Microsoft Academic Search

    Nand Lal Singh

    1947-01-01

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

  11. Thermal activation of copper carbonate

    E-print Network

    Z. Ding; R. L. Frost; J. T. Kloprogge

    Much interest focuses on the use of nano-scale copper and copper oxide for catalyst use [1]. The copper oxide may be used as a solid solution or as a mixture of mixed oxides [2-6]. The application of these mixed oxides is in environmental applications such as the catalytic oxidation of carbon monoxide and the wet oxidation of organics in aqueous systems [5,6]. These nano-scale chemicals are produced through the thermal decomposition of copper salts such as copper carbonate, copper hydroxy-carbonate either synthetic or natural (malachite) [7-9]. Many studies of the thermal treatment of these copper carbonates have been undertaken [9-16]. The use of thermogravimetry to assess the effect of mechanochemical activation by dry grinding of malachite determined the mass loss of water and carbon dioxide separately and/or together for Cu2(OH)2CO3 samples untreated and ground for different times [17,18]. Often the thermal analysis is used to determine the effectiveness of catalyst precursors [19]. Indeed copper carbonates and nitrates can form part of the basic synthesis of superconductors. Thus there is a need to understand the thermal decomposition and surface reactions during thermal

  12. Lead and Copper Control 101

    EPA Science Inventory

    This presentation is an overview of the most important water treatment strategies for the control of lead and copper release from drinking water corrosion. In addition to the sections specifically on lead and copper treatment, sections are included that cover sampling to find le...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. Copper-nickel alloys for marine applications

    Microsoft Academic Search

    Carol A. Powell; James F. Jenkins

    2000-01-01

    Copper alloys have been used for many centuries for their ease of fabrication, and corrosion resistance. In marine applications, copper and some copper alloys also have the property of possessing a high resistance to the attachment and growth of marine organisms that foul most other materials exposed to the ocean. The addition of nickel to copper increases its strength and

  19. Effect of deposition temperature on the structural and optical properties of chemically prepared nanocrystalline lead selenide thin films

    PubMed Central

    Hussain, Amir; Rahman, Atowar

    2012-01-01

    Summary Nanocrystalline lead selenide (PbSe) thin films were prepared on glass substrates by a chemical bath deposition method, using sodium selenosulfate (Na2SeSO3) as a source of Se2? ions, and lead acetate as a source of Pb2+ ions. Trisodium citrate (TSC) was used as a complexing agent. PbSe films were prepared at various deposition temperatures while the pH value was kept fixed at 11, and the effect on the resulting film properties was studied by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and optical absorption studies. The structural parameters, such as the lattice constant (a), crystallite size (D), dislocation density (?) and microstrain (?) were evaluated from the XRD spectra. It was found that average crystallite size, as calculated from Scherrer’s formula, increased from 23 to 33 nm as the deposition temperature was varied from 303 to 343 K. The dislocation density and microstrain were found to vary inversely with the crystallite size, whereas the lattice constant was found to increase with an increase in crystallite size. The optical absorption spectra of the nanocrystalline PbSe films showed a blue shift, and the optical band gap (E g ) was found to increase from 1.96 to 2.10 eV with the decrease in crystallite size. PMID:23016148

  20. Investigation of reaction mechanisms of bismuth tellurium selenide nanomaterials for simple reaction manipulation causing effective adjustment of thermoelectric properties.

    PubMed

    Kim, Cham; Kim, Dong Hwan; Kim, Jong Tae; Han, Yoon Soo; Kim, Hoyoung

    2014-01-22

    We synthesized ternary n-type bismuth tellurium selenide nanomaterials for thermoelectric applications via a water-based chemical reaction under an atmospheric environment. In this work, bismuth nitrate was employed as a bismuth precursor and was hydrolyzed to form bismuth hydroxide in an aqueous solution. Ascorbic acid was used to dissolve the bismuth hydroxide and give a reactive bismuth source (Bi(3+) ions) that was able to react with anion sources (Te(2-)/Se(2-) ions). Ascorbic acid played a role in reducing bismuth hydroxide to an unreactive bismuth source (bismuth particles, Bi(0)). We confirmed that ascorbic acid dissolved or reduced bismuth hydroxide depending on the solution pH. Because either Bi(3+) ions or bismuth particles were generated depending on the pH, the nanomaterial stoichiometry was pH dependent. Nanomaterials prepared at various pH levels were individually sintered using a spark plasma sintering process to measure their thermoelectric transport properties (i.e., carrier concentration, electrical resistivity, Seebeck coefficient, and thermal conductivity). We observed how the transport properties were affected through adjustment of the pH of the reaction and found an appropriate pH for optimizing the transport properties, which resulted in enhancement of the thermoelectric performance. PMID:24372342

  1. Atmospheric Doping Affects on the Transport Properties of the Topological Insulator Bismuth Selenide (Bi2Se3) Grown By MBE

    NASA Astrophysics Data System (ADS)

    Brahlek, Matthew; Kim, Yong Seung; Bansal, Namrata; Edrey, Eliav; Oh, Seongshik

    2011-03-01

    During the last five years much experimental work has been done to determine if the theoretical prediction of topological insulting (TI) states truly exist. Angle resolved photo emission spectroscopy (ARPES) measurements have shown that a Dirac type linear dispersion does exist for a variety of materials, and the surface states have been observed by direct transport measurements. The next challenge is to isolate the surface electrons by removing the bulk conduction. This not trivial because bismuth selenide's Fermi energy sits in the conduction band, and most of the measured carriers are due to these bulk states. The prediction is that the surface states are robust under perturbation, but like standard semiconductors, Bi2Se3's bulk states are sensitive to doping. I will report on our work done on how the transport properties of MBE grown Bi2Se3 thin films are affected by atmospheric dopants such as oxygen and water vapor. Future prospects for studying TIs such Bi2Se3 and ultimately building a device depend on being able to tune the Fermi level into the gap thereby isolating the surface states, and then passivating the surface against contamination due to atmospheric oxygen and water vapor.

  2. Electric double-layer transistor using layered iron selenide Mott insulator TlFe1.6Se2

    PubMed Central

    Katase, Takayoshi; Hiramatsu, Hidenori; Kamiya, Toshio; Hosono, Hideo

    2014-01-01

    A1–xFe2–ySe2 (A = K, Cs, Rb, Tl) are recently discovered iron-based superconductors with critical temperatures (Tc) ranging up to 32 K. Their parent phases have unique properties compared with other iron-based superconductors; e.g., their crystal structures include ordered Fe vacancies, their normal states are antiferromagnetic (AFM) insulating phases, and they have extremely high Néel transition temperatures. However, control of carrier doping into the parent AFM insulators has been difficult due to their intrinsic phase separation. Here, we fabricated an Fe-vacancy-ordered TlFe1.6Se2 insulating epitaxial film with an atomically flat surface and examined its electrostatic carrier doping using an electric double-layer transistor (EDLT) structure with an ionic liquid gate. The positive gate voltage gave a conductance modulation of three orders of magnitude at 25 K, and further induced and manipulated a phase transition; i.e., delocalized carrier generation by electrostatic doping is the origin of the phase transition. This is the first demonstration, to the authors' knowledge, of an EDLT using a Mott insulator iron selenide channel and opens a way to explore high Tc superconductivity in iron-based layered materials, where carrier doping by conventional chemical means is difficult. PMID:24591598

  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. Facile hot-injection synthesis of stoichiometric Cu2ZnSnSe4 nanocrystals using bis(triethylsilyl) selenide.

    PubMed

    Jin, Chunyu; Ramasamy, Parthiban; Kim, Jinkwon

    2014-07-01

    Cu2ZnSnSe4 is a prospective material as an absorber in thin film solar cells due to its many advantages including direct band gap, high absorption coefficient, low toxicity, and relative abundance (indium-free) of its elements. In this report, CZTSe nanoparticles have been synthesized by the hot-injection method using bis-(triethylsilyl)selenide [(Et3Si)2Se] as the selenium source for the first time. Energy dispersive X-ray spectroscopy (EDS) confirmed the stoichiometry of CZTSe nanoparticles. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies showed that the nanocrystals were single phase polycrystalline with their size within the range of 25-30 nm. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy measurements ruled out the existence of secondary phases such as Cu2SnSe3 and ZnSe. The effect of reaction time and precursor injection order on the formation of stoichiometric CZTSe nanoparticles has been studied by Raman spectroscopy. UV-vis-NIR data indicate that the CZTSe nanocrystals have an optical band gap of 1.59 eV, which is optimal for photovoltaic applications. PMID:24823944

  6. Volume 7. Copper base powder metallurgy

    SciTech Connect

    Taubenblat, P.W. (ed.)

    1980-01-01

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

  7. Selecting copper and copper alloys; Part 2: Cast products

    SciTech Connect

    Peters, D.T. (Copper Development Association Inc., New York, NY (United States)); Kundig, K.J.A. (Kundig (Konrad J.A.), Randolph, NJ (United States))

    1994-06-01

    This article provides an introduction to the properties, characteristics, and applications of cast coppers and copper alloys. An overview of alloy families is presented since it is impractical to describe all 130 standard grades in detail. However, additional technical information is readily available from the Copper Development Assn. Inc. (CDA) and the resources listed in the references and bibliography at the end of the article. Copper casting alloys are primarily selected for either their corrosion resistance, or their combination of corrosion resistance and mechanical properties. The materials also feature good castability, high machinability, and, compared with other corrosion-resistant alloys, reasonable cost. Additional benefits include biofouling resistance--important in marine applications--and a spectrum of attractive colors. Many of the alloys also have favorable tribological properties, which explains their widespread use for sleeve bearings, wear plates, gears, and other wear-prone components.

  8. NID Copper Sample Analysis

    SciTech Connect

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12

    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 MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one 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. 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 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 in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  9. Arsenic activities in molten copper and copper sulfide melts

    Microsoft Academic Search

    M. Hino; J. M. Toguri

    1986-01-01

    In recent years, the concentration of the group Va elements such as arsenic, antimony, and bismuth has been increasing in\\u000a copper concentrates. The elimination and recovery of these elements during the copper smelting process have presented serious\\u000a problems. While the distribution of minor elements has been studied extensively, very little knowledge exists on the activities\\u000a of these minor elements in

  10. 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

  11. Genome Sequences of Two Copper-Resistant Escherichia coli Strains Isolated from Copper-Fed Pigs

    PubMed Central

    Lüthje, Freja L.; Hasman, Henrik; Aarestrup, Frank M.; Alwathnani, Hend A.

    2014-01-01

    The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances. PMID:25540351

  12. Spectroscopic studies of copper enzymes

    Microsoft Academic Search

    D. M. Dooley; R. Moog; W. Zumft; S. H. Koenig; R. A. Scott; C. E. Cote; M. McGuirl

    1986-01-01

    Several spectroscopic methods, including absorption, circular dichroism (CD), magnetic CD (MCD), X-ray absorption, resonance Raman, EPR, NMR, and quasi-elastic light-scattering spectroscopy, have been used to probe the structures of copper-containing amine oxidases, nitrite reductase, and nitrous oxide reductase. The basic goals are to determine the copper site structure, electronic properties, and to generate structure-reactivity correlations. Collectively, the results on the

  13. Majorana Electroformed Copper Mechanical Analysis

    Microsoft Academic Search

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

    2012-01-01

    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

  14. Occupational genotoxicity among copper smelters.

    PubMed

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

    2012-10-01

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

  15. Metal selenides as a new class of electrocatalysts for quantum dot-sensitized solar cells: a tale of Cu(1.8)Se and PbSe.

    PubMed

    Choi, Hye Mi; Ji, In Ae; Bang, Jin Ho

    2014-02-26

    The development of a Pt-free, highly active electrocatalyst for a counter electrode (CE) is vital to the construction of highly efficient quantum dot-sensitized solar cells (QDSSCs). As an alternative to Pt, the use of various metal sulfides, such as Cu2S, CoS, and PbS, has been successfully demonstrated; however, the studies on the utilization of non-sulfide materials have been scarcely reported. In this regard, we examined eight different types of binary metal selenides as new candidate materials, and found that the electrocatalytic activity of Cu1.8Se and PbSe toward polysulfide reduction was superior to that of Pt. In depth investigation into these two materials further revealed that, while the electrocatalytic activity of both metal selenides surpasses that of Pt, the long-term utilization of the PbSe CE is hindered by the formation of PbO on the surface of PbSe, which is attributed to the instability of PbSe under air. Unlike PbSe, Cu1.8Se was found to be chemically stable with a polysulfide electrolyte and was even better than Cu2S, a commonly used CE material for QDSSCs. Using the Cu1.8Se CE, we obtained a power conversion efficiency of 5.0% for CdS/CdSe-sensitized solar cells, which was an efficiency almost twice that obtained from Pt CE. This work provides a new application for metal selenides, which have been traditionally utilized as sensitizers for QDSSCs. PMID:24490774

  16. "Pulling the plug" on cellular copper: The role of mitochondria in copper export Scot C. Leary a,

    E-print Network

    Leary, Scot

    , are required for normal cell physiology. Copper deficiency and overload syndromes in humans that result to balance global copper content, and to distribute copper to different subcellular compartments

  17. METAL-SELENIUM INTERACTIONS. SYNTHESIS AND CRYSTAL STRUCTURE OF [DIIODO{1,1?-METHYLENE-BIS (DIPHENYL PHOSPHINE SELENIDE)}] ZINC(II)

    Microsoft Academic Search

    Tarlok S. Lobana; Rajbir Hundal; Peter Turner

    2001-01-01

    Reaction of 1,1?-methylenebis(diphenylphosphine selenide) {Ph2P(Se)—CH2—P(Se)Ph2, dpmSe2} with zinc(II) diiodide in dry diethylether-benzene mixture formed Znl2(dpmSe2) (1), which has been characterised with the help of analytical data, IR spectroscopy and single crystal X-ray crystallography. Zinc(II) is bonded to two iodine atoms {Zn—I, 2.5732(9), 2.5584(7) Å} and two selenium atoms {Zn—Se, 2.5135(8), 2.4906(10) Å}. The angles about Zn vary from 103.56(3) to

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

    NASA Astrophysics Data System (ADS)

    Kheraj, Vipul; Patel, K. K.; Patel, S. J.; Shah, D. V.

    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 high absorption co-efficient and direct band-gap. Moreover, all the constituent elements of CZTS are non-toxic and aplenty on the earth-crust, making it a potential candidate for the thin-film photovoltaics. Here we report the synthesis of CZTS powder from its constituent elements, viz. copper, zinc, tin and sulphur, in an evacuated Quartz ampoule at 1030 K temperature. The sulphur content in the raw mixture in the ampoule was varied and optimised in order to attain the desired atomic stoichiometry of the compound. The synthesised powder was characterised by X-Ray diffraction technique (XRD), Raman Scattering Spectroscopy, Energy Dispersive Analysis of X-Ray (EDAX) and UV-Visible Absorption Spectra. The XRD Patterns of the synthesised compound show the preferred orientation of (112), (220) and (312) planes, confirming the Kesterite structure of CZTS. The chemical composition of the powder was analysed by EDAX and shows good atomic stoichiometry of the constituent elements in the CZTS compound. The UV-Vis absorption spectra confirm the direct band-gap of about 1.45 eV, which is quite close to the optimum value for the semiconductor material as an absorber in solar-cells.

  19. SYNTHESIS OF COPPER METAL\\/SALTS FROM COPPER BLEED SOLUTION OF A COPPER PLANT

    Microsoft Academic Search

    Sarita Kumari; A. Agrawal; D. Bagchi; V. Kumar; B. D. Pandey

    2006-01-01

    Copper bleed solution (CBS) generated during the electrorefining of anode copper contains 40 g\\/L Cu, 10–20 g\\/L Ni, and 170–200 g\\/L H2SO4, along with other impurities in different quantities. In order to get the valuable metals from this CBS, studies have been carried out to crystallize and recover metal salts on bench scale with\\/without partial decopperization from the point of view of reuse

  20. BTA copper complexes.

    PubMed

    Friedrich, Manfred; Gálvez-Ruiz, Juan Carlos; Klapötke, Thomas M; Mayer, Peter; Weber, Birgit; Weigand, Jan J

    2005-10-31

    Cupric oxide is one of the most important additives used (a) to catalyze decomposition reactions in gas generators to obtain cooler reaction gases, (b) as burning enhancer for ammonium perchlorate-based composite propellants, and (c) as coloring agent in pyrotechnics. In this context, the reaction of Cu(2+) ions in aqueous ammonia solution with bis(tetrazolyl)amine (H(2)bta) was investigated. Depending on the reaction conditions three complexes were obtained: Cu(bta)(NH(3))(2) (1), Cu(bta)(NH(3))(2).H(2)O (2), and (NH(4))(2)Cu(bta)(2).2.5H(2)O (3). The crystal structures of 1 and 2 are discussed with respect to the coordination mode of the dianion of N,N-bis(1(2)H-tetrazol-5-yl)-amine (bta), which mediates in the case of 1 and 2 weak superexchange interactions between the adjacent magnetic transition-metal Cu(II) cations. These antiferromagnetic interactions result from 1D copper chains over an hidden azide end-to-end bridge. Interestingly, the structural arrangement of 1 completely changes in the presence of crystal-bound water. Moreover, some physicochemical properties (e.g., heat of formation, friction, and impact sensitivity, DSC) of these complexes with respect to high-energetic materials are discussed. PMID:16241154

  1. 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.

  2. Physical and biophysical assessment of highly fluorescent, magnetic quantum dots of a wurtzite-phase manganese selenide system

    NASA Astrophysics Data System (ADS)

    Sarma, Runjun; Das, Queen; Hussain, Anowar; Ramteke, Anand; Choudhury, Amarjyoti; Mohanta, Dambarudhar

    2014-07-01

    Combining fluorescence and magnetic features in a non-iron based, select type of quantum dots (QDs) can have immense value in cellular imaging, tagging and other nano-bio interface applications, including targeted drug delivery. Herein, we report on the colloidal synthesis and physical and biophysical assessment of wurtzite-type manganese selenide (MnSe) QDs in cell culture media. Aiming to provide a suitable colloidal system of biological relevance, different concentrations of reactants and ligands (e.g., thioglycolic acid, TGA) have been considered. The average size of the QDs is ˜7 nm, which exhibited a quantum yield of ˜75% as compared to rhodamine 6 G dye®. As revealed from time-resolved photoluminescence (TR-PL) response, the near band edge emission followed a bi-exponential decay feature with characteristic times of ˜0.64 ns and 3.04 ns. At room temperature, the QDs were found to exhibit paramagnetic features with coercivity and remanence impelled by TGA concentrations. With BSA as a dispersing agent, the QDs showed an improved optical stability in Dulbecco’s Modified Eagle Media® (DMEM) and Minimum Essential Media® (MEM), as compared to the Roswell Park Memorial Institute® (RPMI-1640) media. Finally, the cell viability of lymphocytes was found to be strongly influenced by the concentration of MnSe QDs, and had a safe limit upto 0.5 ?M. With BSA inclusion in cell media, the cellular uptake of MnSe QDs was observed to be more prominent, as revealed from fluorescence imaging. The fabrication of water soluble, nontoxic MnSe QDs would open up an alternative strategy in nanobiotechnology, while preserving their luminescent and magnetic properties intact.

  3. 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.

  4. Genes involved in copper resistance influence survival of Pseudomonas aeruginosa on copper surfaces

    PubMed Central

    Elguindi, Jutta; Wagner, Janine; Rensing, Christopher

    2013-01-01

    Aims To evaluate the killing of Pseudomonas aeruginosa PAO1 on copper cast alloys and the influence of genes on survival on copper containing medium and surfaces. Methods and Results Different strains of P. aeruginosa were inoculated on copper containing medium or different copper cast alloys and the survival rate determined. The survival rates were compared to rates on copper-free medium and stainless steel as control. In addition, the effect of temperature on survival was examined. Conclusions Copper cast alloys had previously shown to be bactericidal to various bacteria but the mechanism of copper-mediated killing is still not known. In this report we demonstrate that P. aeruginosa PAO1 is rapidly killed on different copper cast alloys and that genes involved in conferring copper resistance in copper-containing medium also influenced survival on copper cast alloys. We also show that the rate of killing is influenced by temperature. PMID:19239551

  5. 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.

  6. Femtosecond laser ablation of copper

    NASA Astrophysics Data System (ADS)

    Goh, Yeow-Whatt; Lu, Yong-Feng; Hong, Ming-Hui; Chong, Tow Chong

    2003-02-01

    In recent years, femtosecond (fs) laser ablation has attracted much interest in both basic and applied physics, mainly because of its potential application in micromachining and pulsed laser deposition. Ultrashort laser ablation have the capability to ablate materials precisely with little or no collateral damage, even with materials that are impervious to laser energy from conventional pulsed lasers. The extreme intensities and short timescale at which ultrashort pulsed lasers operate differentiate them from other lasers such as nanosecond laser. In this work, we investigate the expansion dynamics of Cu (copper) plasma generated by ultrashort laser ablation of pure copper targets by optically examining the plasma plume. Time-integrated optical emission spectroscopy measurements by using intensified charged couple detector array (ICCD) imaging were used to detect the species present in the plasma and to study the laser-generated plasma formation and evolution. Temporal emission profiles are measured. Our interest in the dynamics of laser-generated copper plasma arises from the fact that copper has been considered as a substitute for Aluminum (Al) interconnects/metallization in ULSI devices (for future technology). It is important to know the composition and behavior of copper plasma species for the understanding of the mechanisms involved and optimizing the micro-machining processes and deposition conditions.

  7. Spray pyrolysis of tin selenide thin-film semiconductors: the effect of selenium concentration on the properties of the thin films

    NASA Astrophysics Data System (ADS)

    Fadavieslam, M. R.; Bagheri-Mohagheghi, M. M.

    2013-08-01

    Thin films of tin selenide (SnxSey) with an atomic ratio of , 1 and 1.5 were prepared on a glass substrate at T = 470°C using a spray pyrolysis technique. The initial materials for the preparation of the thin films were an alcoholic solution consisting of tin chloride (SnCl4· 5H2O) and selenide acide (H2SeO3). The prepared thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy, scanning tunneling microscopy, scanning helium ion microscopy, and UV-vis spectroscopy. The photoconductivity and thermoelectric effects of the SnxSey thin films were then studied. The SnxSey thin films had a polycrystalline structure with an almost uniform surface and cluster type growth. The increasing atomic ratio of r in the films, the optical gap, photosensitivity and Seebeck coefficient were changed from 1.6 to 1.37 eV, 0.01 to 0.31 and -26.2 to -42.7 mV/K (at T = 350 K), respectively. In addition, the XRD patterns indicated intensity peaks in r = 1 that corresponded to the increase in the SnSe and SnSe2 phases.

  8. 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

  9. Recovery of nickel powder from copper bleed electrolyte of an Indian copper smelter by electrolysis

    Microsoft Academic Search

    Archana Agrawal; D. Bagchi; S. Kumari; V. Kumar; B. D. Pandey

    2007-01-01

    When nickel concentration increases in the copper sulphate electrolyte during electrolysis, it starts electrodepositing on the copper cathode thereby affecting the purity of the copper. In order to produce high quality copper cathodes with less than 1 ppm Ni, it became necessary to bleed-off large volumes of foul electrolyte contaminated with nickel and other impurities. The study reported in this paper

  10. 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

  11. Diamine ligands in copper-catalyzed reactions

    E-print Network

    Surry, David S.

    The utility of copper-mediated cross-coupling reactions has been significantly increased by the development of mild reaction conditions and the ability to employ catalytic amounts of copper. The use of diamine-based ligands ...

  12. 21 CFR 73.2647 - Copper powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity...Copper powder may be safely used in coloring cosmetics generally, including cosmetics intended for use in the area of the eye,...

  13. 21 CFR 73.2647 - Copper powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity...Copper powder may be safely used in coloring cosmetics generally, including cosmetics intended for use in the area of the eye,...

  14. 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 ...

  15. Molecular Mediators Governing Iron-Copper Interactions

    PubMed Central

    Gulec, Sukru; Collins, James F.

    2015-01-01

    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

  16. 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

  17. Leaching of Copper Ore by Thiobacillus Ferrooxidans.

    ERIC Educational Resources Information Center

    Lennox, John; Biaha, Thomas

    1991-01-01

    A quantitative laboratory exercise based upon the procedures copper manufacturers employ to increase copper production is described. The role of chemoautotrophic microorganisms in biogeologic process is emphasized. Safety considerations when working with bacteria are included. (KR)

  18. 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].

  19. Copper nanocluster diffusion in carbon nanotube

    Microsoft Academic Search

    Ho Jung Hwang; Oh-Keun Kwon; Jeong Won Kang

    2004-01-01

    The diffusion of copper nanocluster in carbon nanotube was investigated using a classical molecular dynamics simulation and three empirical potential functions. The results indicated a growth mechanism of the copper-filled ultra-thin carbon nanotubes: the copper nanoclusters inserted into carbon nanotubes swiftly migrate along the tube axis, and then the copper nanowires grow in the ultra-thin carbon nanotubes. Periodic energy barriers

  20. Textured carbon surfaces on copper by sputtering

    NASA Technical Reports Server (NTRS)

    Curren, A. N. (inventor); Jensen, K. A. (inventor); Roman, R. F. (inventor)

    1986-01-01

    A very thin layer of highly textured carbon is applied to a copper surface by a triode sputtering process. A carbon target and a copper substrate are simultaneously exposed to an argon plasma in a vacuum chamber. The resulting carbon surface is characterized by a dense, random array of needle like spires or peaks which extend perpendicularly from the copper surface. The coated copper is especially useful for electrode plates in multistage depressed collectors.

  1. Copper transport and Alzheimer’s disease

    Microsoft Academic Search

    Ian G. Macreadie

    2008-01-01

    This brief review discusses copper transport in humans, with an emphasis on knowledge learned from one of the simplest model\\u000a organisms, yeast. There is a further focus on copper transport in Alzheimer’s Disease (AD). Copper homeostasis is essential\\u000a for the well-being of all organisms, from bacteria to yeast to humans: survival depends on maintaining the required supply\\u000a of copper for

  2. Contribution of Copper Ion Resistance to Survival of Escherichia coli on Metallic Copper Surfaces?

    PubMed Central

    Santo, Christophe Espírito; Taudte, Nadine; Nies, Dietrich H.; Grass, Gregor

    2008-01-01

    Bacterial contamination of touch surfaces poses a serious threat for public health. The use of bactericidal surface materials, such as copper and its alloys, might constitute a way to aid the use of antibiotics and disinfectants, thus minimizing the risk of emergence and spread of multiresistant germs. The survival of Escherichia coli on metallic copper surfaces has been studied previously; however, the mechanisms underlying bacterial inactivation on copper surfaces have not been elucidated. Data presented in this study suggest that bacteria are killed rapidly on dry copper surfaces. Several factors, such as copper ion toxicity, copper chelators, cold, osmotic stress, and reactive oxygen species, but not anaerobiosis, influenced killing rates. Strains deleted in copper detoxification systems were slightly more sensitive than was the wild type. Preadaptation to copper enhanced survival rates upon copper surface exposure. This study constitutes a first step toward understanding the reasons for metallic copper surface-mediated killing of bacteria. PMID:18156321

  3. Copper accumulation in the crayfish (Orconectes rusticus)

    SciTech Connect

    Evans, M.L.

    1980-06-01

    The purpose of this study was to determine whether or not the crayfish, O. rusticus could fulfill Nehring's (1976) criteria for a good biological monitor of heavy metal pollution. Since there is some evidence that the cupric ion is the most toxic form of aqueous copper, crayfish-accumulated copper was compared to both total and cupric copper in the culture water.

  4. Acute copper toxicosis in the Canada goose

    Microsoft Academic Search

    B. M. Henderson; R. W. Winterfield

    2009-01-01

    Acute copper toxicosis resulted in Canada geese, Branta canadensis, following ingestion of copper sulfate at about 600 mg\\/kg from a small man-made pond on a game farm. The lesions were those associated with copper toxicosis in other avian species. The primary patholgic change was necrosis and sloughing of the proventriculus and gizzard. A greenish discoloration of the lungs also occured.

  5. 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.

  6. 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...

  7. 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....

  8. 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...

  9. 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.

  10. 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....

  11. 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

  12. 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....

  13. 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....

  14. 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....

  15. Ferric leaching of copper slag flotation tailings

    Microsoft Academic Search

    F. Carranza; N. Iglesias; A. Mazuelos; R. Romero; O. Forcat

    2009-01-01

    The pyrometallurgical production of copper generates slags, a residue with a significant content of this metal. Copper can be recovered from the slags by froth flotation after cooling, crushing, and grinding. The obtained Cu-concentrate is sent to the pyrometallurgical process. If grinding is not fine enough for efficient flotation, copper is lost in tailings. In this paper, the ferric leaching

  16. Mechanism of Diffusion of Copper in Germanium

    Microsoft Academic Search

    F. C. Frank; D. Turnbull

    1956-01-01

    To explain the rapid diffusivity of copper in germanium and its dependence on structure, it is proposed that the copper be dissolved in two states, interstitial and substitutional. It is deduced that in the interstitial state the solubility of copper is about 10-2 times less and the diffusivity many orders of magnitude greater than in the substitutional state. Conversion from

  17. 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.

  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. 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

  20. 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.

  1. 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

  2. a Study of Volatile Precursors for the Growth of Cadmium Sulphide and Cadmium Selenide by Metal Organic Chemical Vapour Deposition.

    NASA Astrophysics Data System (ADS)

    Beer, Michael P.

    Available from UMI in association with The British Library. The wide-band-gap semiconductors, cadmium sulphide and cadmium selenide, may be grown by Metal Organic Chemical Vapour Deposition (MOCVD). This method typically involves the reaction of gaseous streams of Me_2 Cd and H_2Y (Y = S, Se) over a heated substrate (usually gallium arsenide) on which the desired compound is grown as an epitaxial layer. Unfortunately, the precursors start to react in the cold zone of the reactor, that is before they reach the heated substrate. This problem is known as prereaction. The problem of prereaction is partially reduced by the use of adducts of dimethyl cadmium in place of the free dialkyl compound although the mechanism by which such adducts block prereaction is unknown. Accordingly, a study of adducts of dimethyl cadmium was undertaken with a view to determining their properties in all phases. The adduct of Me_2Cd with 2,2^ '-bipyridyl was found to be monomeric in the solid state while that with 1,4-dioxane, a volatile compound used for prereaction reduction, was found to be polymeric. A study of adducts in the gas phase using mass spectrometry and gas phase Fourier transform infrared spectroscopy gave no evidence to suggest there is any gas phase association between 1,4-dioxane and dimethyl cadmium. With the 2,2 ^'-bipyridyl adduct some evidence for partial retention of coordinate bonds upon sublimation was obtained. The solid adduct of Me _2Cd with N,N,N^' ,N^'-tetramethylethylenediamine (TMEDA) was prepared as it was hoped that the flexibility of the aliphatic Lewis base would permit the formation of an adduct containing strong co-ordinate bonds which would remain intact upon sublimation. Using gas phase electron diffraction, the structure of the adduct of Me_2Cd and TMEDA was determined. It was shown to exist in the gas phase purely as the associated monomeric species. The adduct was then employed for the growth of CdS and CdSe in an industrial MOCVD apparatus. The possibility of the occurrence of surface initiated processes leading to prereaction was considered. We examined the sulphur containing molecules ethylene sulphide and propylene sulphide with a view to their replacing H_2S in the MOCVD growth of CdS. These precursors were seen to allow the growth of CdS at the relatively low temperature of 350^circ C and there was no evidence of prereaction.(Abstract shortened by UMI.).

  3. Copper Nanotubes for Packaging Applications

    Microsoft Academic Search

    D. Choi; V. Fucsko; Eui-Hyeok Yang

    2008-01-01

    In this paper, we present a process for fabricating Copper (Cu) nanotubes, which can be utilized for novel electrical interconnect materials. Because of superior properties in electromigration and thermal management to aluminum, Cu technology has been attractive to the semiconductor industry. Cu nanotubes can be fabricated by electrodeposition using alumina nanopore templates. Nanotubes can provide high surface-to-volume ratio in nanostructures

  4. 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.

  5. 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…

  6. 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)

  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. Crystallization of copper metaphosphate glass

    NASA Technical Reports Server (NTRS)

    Bae, Byeong-Soo; Weinberg, Michael C.

    1993-01-01

    The effect of the valence state of copper in copper metaphosphate glass on the crystallization behavior and glass transition temperature has been investigated. The crystallization of copper metaphosphate is initiated from the surface and its main crystalline phase is copper metaphosphate (Cu(PO)3),independent of the (Cu sup 2+)/(Cu(total)). However, the crystal morphology, the relative crystallization rates, and their temperature dependences are affected by the (Cu sup 2+)/(Cu (total)) ratio in the glass. On the other hand, the totally oxidized glass crystallizes from all over the surface. The relative crystallization rate of the reduced glass to the totally oxidized glass is large at low temperature, but small at high temperature. The glass transition temperature of the glass increases as the (Cu sup 2+)/(Cu(total)) ratio is raised. It is also found that the atmosphere used during heat treatment does not influence the crystallization of the reduced glass, except for the formation of a very thin CuO surface layer when heated in air.

  9. 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)....

  10. The Future of Copper Metallurgy

    Microsoft Academic Search

    FATHI HABASHI

    1995-01-01

    Copper technology changed from the vertical to the horizontal furnace and from the roast reaction to the converting reaction towards the end of the last century. However, the horizontal furnace proved to be an inefficient and polluting reactor. As a result many attempts were made to replace it. In the past 40 years new successful melting processes were introduced on

  11. 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,...

  12. Spectroscopic studies of copper enzymes

    SciTech Connect

    Dooley, D.M.; Moog, R.; Zumft, W.; Koenig, S.H.; Scott, R.A.; Cote, C.E.; McGuirl, M.

    1986-05-01

    Several spectroscopic methods, including absorption, circular dichroism (CD), magnetic CD (MCD), X-ray absorption, resonance Raman, EPR, NMR, and quasi-elastic light-scattering spectroscopy, have been used to probe the structures of copper-containing amine oxidases, nitrite reductase, and nitrous oxide reductase. The basic goals are to determine the copper site structure, electronic properties, and to generate structure-reactivity correlations. Collectively, the results on the amine oxidases permit a detailed model for the Cu(II) sites in these enzymes to be constructed that, in turn, rationalizes the ligand-binding chemistry. Resonance Raman spectra of the phenylhydrazine and 2,4-dinitrophenyl-hydrazine derivatives of bovine plasma amine oxidase and models for its organic cofactor, e.g. pyridoxal, methoxatin, are most consistent with methoxatin being the intrinsic cofactor. The structure of the Cu(I) forms of the amine oxidases have been investigated by X-ray absorption spectroscopy (XAS); the copper coordination geometry is significantly different in the oxidized and reduced forms. Some anomalous properties of the amine oxidases in solution are explicable in terms of their reversible aggregation, which the authors have characterized via light scattering. Nitrite and nitrous oxide reductases display several novel spectral properties. The data suggest that new types of copper sites are present.

  13. COPPER CORROSION AND SOLUBILITY RESEARCH

    EPA Science Inventory

    This poster provides a very cursory summary of TTEB in-house copper research experimental systems, and extramural research projects. The field studies summarized are the Indian Hill (OH) study of the use of orthophosphate for reducing cuprosolvency in a high alkalinity water, an...

  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. 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.

  16. Copper economy in Chlamydomonas: Prioritized allocation and reallocation of copper to respiration vs. photosynthesis.

    PubMed

    Kropat, Janette; Gallaher, Sean D; Urzica, Eugen I; Nakamoto, Stacie S; Strenkert, Daniela; Tottey, Stephen; Mason, Andrew Z; Merchant, Sabeeha S

    2015-03-01

    Inorganic elements, although required only in trace amounts, permit life and primary productivity because of their functions in catalysis. Every organism has a minimal requirement of each metal based on the intracellular abundance of proteins that use inorganic cofactors, but elemental sparing mechanisms can reduce this quota. A well-studied copper-sparing mechanism that operates in microalgae faced with copper deficiency is the replacement of the abundant copper protein plastocyanin with a heme-containing substitute, cytochrome (Cyt) c6. This switch, which is dependent on a copper-sensing transcription factor, copper response regulator 1 (CRR1), dramatically reduces the copper quota. We show here that in a situation of marginal copper availability, copper is preferentially allocated from plastocyanin, whose function is dispensable, to other more critical copper-dependent enzymes like Cyt oxidase and a ferroxidase. In the absence of an extracellular source, copper allocation to Cyt oxidase includes CRR1-dependent proteolysis of plastocyanin and quantitative recycling of the copper cofactor from plastocyanin to Cyt oxidase. Transcriptome profiling identifies a gene encoding a Zn-metalloprotease, as a candidate effecting copper recycling. One reason for the retention of genes encoding both plastocyanin and Cyt c6 in algal and cyanobacterial genomes might be because plastocyanin provides a competitive advantage in copper-depleted environments as a ready source of copper. PMID:25646490

  17. Copper economy in Chlamydomonas: Prioritized allocation and reallocation of copper to respiration vs. photosynthesis

    PubMed Central

    Kropat, Janette; Gallaher, Sean D.; Urzica, Eugen I.; Nakamoto, Stacie S.; Strenkert, Daniela; Tottey, Stephen; Mason, Andrew Z.; Merchant, Sabeeha S.

    2015-01-01

    Inorganic elements, although required only in trace amounts, permit life and primary productivity because of their functions in catalysis. Every organism has a minimal requirement of each metal based on the intracellular abundance of proteins that use inorganic cofactors, but elemental sparing mechanisms can reduce this quota. A well-studied copper-sparing mechanism that operates in microalgae faced with copper deficiency is the replacement of the abundant copper protein plastocyanin with a heme-containing substitute, cytochrome (Cyt) c6. This switch, which is dependent on a copper-sensing transcription factor, copper response regulator 1 (CRR1), dramatically reduces the copper quota. We show here that in a situation of marginal copper availability, copper is preferentially allocated from plastocyanin, whose function is dispensable, to other more critical copper-dependent enzymes like Cyt oxidase and a ferroxidase. In the absence of an extracellular source, copper allocation to Cyt oxidase includes CRR1-dependent proteolysis of plastocyanin and quantitative recycling of the copper cofactor from plastocyanin to Cyt oxidase. Transcriptome profiling identifies a gene encoding a Zn-metalloprotease, as a candidate effecting copper recycling. One reason for the retention of genes encoding both plastocyanin and Cyt c6 in algal and cyanobacterial genomes might be because plastocyanin provides a competitive advantage in copper-depleted environments as a ready source of copper. PMID:25646490

  18. 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}.

  19. 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.

  20. Superior photoluminescence (PL) of Pr³?-In, compared to Pr³?-Ga, selenide-chalcogenide bulk glasses and PL of optically-clad fiber.

    PubMed

    Sakr, H; Furniss, D; Tang, Z; Sojka, L; Moneim, N A; Barney, E; Sujecki, S; Benson, T M; Seddon, A B

    2014-09-01

    The photoluminescent-(PL)-properties of Pr³?-ions in indium-containing selenide-chalcogenide bulk-glasses are found to be superior when compared with gallium-containing analogues. We observe circa doubling of mid-infrared (MIR) PL intensity from 3.5 to 6 ?m for bulk glasses, pumped at 1.55 ?m wavelength, and an increased excited state lifetime at 4.7 ?m. PL is reported in optically-clad fiber. Ga addition is well known to enhance RE³? solubility and PL behavior, and is believed to form ([RE³?]-Se-[Ga(III)]) in the glasses. Indium has the same outer electronic-structure as gallium for solvating the RE-ions. Moreover, indium is heavier and promotes lower phonon energy locally around the RE-ion, thereby enhancing the RE-ion PL behavior, as observed here. PMID:25321504

  1. Design and fabrication of anti-reflection coating on Gallium Phosphide, Zinc Selenide and Zinc Sulfide substrates for visible and infrared application

    NASA Astrophysics Data System (ADS)

    Vápenka, D.; Václavík, J.; Mokrý, P.

    2013-04-01

    Results of design and fabrication of a dual-band anti-reflection coating on a gallium phosphide (GaP), zinc selenide (ZnSe) and zinc sulfide (ZnS) substrates are presented. A multilayer stack structure of antireflection coatings made of zinc sulfide and yttrium fluoride (YF3) was theoretically designed for optical bands between 0.8 and 0.9 ?m and between 9.5 and 10.5 ?m. This stack was designed as efficient for these materials (GaP, ZnS, ZnSe) together. Multilayer stack structure was deposited using thermal evaporation method. Theoretically predicted transmittance spectra were compared with transmitted spectra measured on coated substrates. Efficiency of anti-reflection coating is estimated and discrepancies are analyzed and discussed.

  2. Broadband Second-Harmonic Generation in the Near-Infrared Region in a Tapered Zinc Selenide Slab Using Total Internal Reflection Quasi-Phase Matching

    NASA Astrophysics Data System (ADS)

    Saha, Ardhendu; Deb, Sumita

    2011-10-01

    We analytically describe the concept of broadband second-harmonic generation in the near-IR region in an isotropic tapered semiconductor slab made of zinc selenide. A computer-aided simulation has been carried out to determine the possibility of generating broadband second-harmonic intensity when broadband fundamental laser radiation is allowed to undergo total internal reflection inside the tapered semiconductor slab. The simulated results indicate an extremely broad spectral bandwidth of 557 nm centered at 4.05 µm (3.812 to 4.369 µm) in a 10-mm-long slab with a conversion efficiency of 0.02%. The losses due to absorption and surface roughness of the semiconductor material have been considered in the analysis. The effects of variations in the temperature, length, and tapering angle of the semiconductor slab have been studied for the generated second-harmonic radiation.

  3. Photoluminescence and generation of singlet oxygen by ligand-stabilized gold-selenide clusters [Au18Se8(dppe)6]Br2

    NASA Astrophysics Data System (ADS)

    Lebedkin, Sergei; Langetepe, Timo; Sevillano, Paloma; Fenske, Dieter; Kappes, Manfred M.

    2001-11-01

    Photophysical properties of a novel ligand-stabilized gold-selenide cluster [Au18Se8(dppe)6]Br2 depend strongly on its aggregation state. The polycrystalline compound shows red photoluminescence (PL) with a quantum yield of 0.55/0.05 and characteristic lifetime of ˜12/˜1 ?s at 77/293 K, respectively. The emission was assigned to an excited triplet state. In a solution this state decays more rapidly (?=63 ns in Ar-purged CH2Cl2) and PL is weak. Despite the short lifetime, the cluster in the triplet state efficiently sensitizes singlet oxygen via energy transfer (the quantum yield is 0.17 in air-equilibrated CH2Cl2). Both in the solid state and in a solution the cluster shows good photostability under UV-VIS irradiation.

  4. Resonant effects in the manifestation of hybridized electronic states of iron impurities in the temperature dependences of the absorption coefficient and velocity of ultrasound propagation in mercury selenide

    NASA Astrophysics Data System (ADS)

    Okulov, V. I.; Gudkov, V. V.; Govorkova, T. E.; Zhevstovskikh, I. V.; Lonchakov, A. T.; Paranchich, S. Yu.

    2007-11-01

    The temperature dependences of the absorption coefficient and phase velocity of 52-MHz ultrasonic waves in iron-doped mercury selenide crystals are studied. The presence of impurities in concentrations of about 1019 cm-3 is found to initiate the appearance of a resonance peak in the absorption coefficient at a temperature of about 5 K and the corresponding anomaly in the velocity of the slow transverse wave propagating in the <110> direction. It is shown that the observed effects can be accounted for by the interaction of ultrasound with electrons in the states created in hybridization of the iron impurity donor states with the conduction band states of the crystal. A straightforward theoretical description and quantitative interpretation of these effects are proposed and used to derive data on the hybridized states, which conform with the earlier treatment of the temperature and concentration anomalies of conductivity in the crystals under study.

  5. 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

  6. 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.

  7. 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?

  8. Effect of copper additions on the isothermal bainitic transformation in hypereutectoid copper and copper-nickel steels

    SciTech Connect

    Fourlaris, G.; Baker, A.J. [Univ. of Leeds (United Kingdom). School of Materials] [Univ. of Leeds (United Kingdom). School of Materials; Papadimitriou, G.D. [National Technical Univ. of Athens (Greece). Lab. of Physical Metallurgy] [National Technical Univ. of Athens (Greece). Lab. of Physical Metallurgy

    1996-12-01

    During the isothermal bainitic transformation in hypereutectoid steels alloyed with copper or copper and nickel, it was found that at all the transformation temperatures studied, the formation of equally copper supersaturated bainitic ferrite and cementite always occurred. This observation implies the formation of bainitic ferrite and cementite from the parent austenite phase without redistribution of the alloying elements, since the solubility of copper in cementite is negligible and very low in bainitic ferrite. By carefully designing suitable tempering treatments, it is possible to produce copper precipitation not only within tempered bainitic ferrite in both types of steel using low tempering temperatures, but also within the tempered bainitic cementite of the copper steel at higher tempering temperatures. The interpretation of these experimental data strongly supports the theory that bainite formation is promoted through a shear controlled type of mechanism.

  9. Chronic poisoning by copper in tap water: I. Copper intoxications with predominantly gastointestinal symptoms.

    PubMed

    Eife, R; Weiss, M; Barros, V; Sigmund, B; Goriup, U; Komb, D; Wolf, W; Kittel, J; Schramel, P; Reiter, K

    1999-06-28

    Copper can induce acute and chronic intoxications in humans. Copper in tap water has caused a series of severe systemic diseases in Germany in recent years (copper induced liver cirrhosis). Besides cirrhosis, another type of disease with predominantly gastrointestinal symptoms has occurred which likewise appeared to be induced by copper in tap water. - In a retrospective investigation we looked for additional indications and proof that chronic copper poisoning has been the cause of the observed gastrointestinal diseases. All patients suffering from this type of disease had copper plumbing in their houses. - The patients (children and adults) suffered from nausea, vomiting, colic, and diarrhoea. In the group of infants, one refused formula milk (prepared with tap water) and the others suffered from persistent restlessness, unexplainable screaming (especially at night) and/or long lasting diaper rash. - We accept the diagnosis of chronic copper intoxication as the cause of the gastrointestinal symptoms when at least one of the following criteria were fulfilled: 1. first manifestation, remission and relapse of the disease depend on intake and a non-intake of water containing copper, respectively. 2. hypercupric state of the patients (i.e. pathological high concentrations of the non-ceruloplasmin-bound copper in serum and/or elevated copper levels in urine) 3. signs of systemic copper intoxication in the same patient 4. signs of systemic copper intoxication or hypercupric states in members of the patient s family or in his neighbourhood (non-relatives) - We found that the disease can even be caused by copper concentrations below the allowed concentration given by the German Guidelines for Drinking Water (Trinkwasserverordnung). - The data prove that copper in drinking water can cause gastrointestinal diseases and not only the better known systemic diseases (i.e. copper induced liver cirrhosis). Copper poisoning must be considered as a possible cause of chronic gastrointestinal diseases in those countries in which copper plumbing is common. PMID:10383875

  10. Biosorption and bioreduction of copper from different copper compounds in aqueous solution.

    PubMed

    Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Bento, Fátima M; Camargo, Flávio A O

    2013-06-01

    High copper concentration is toxic for living organisms including humans. Biosorption is a bioremediation technique that can remove copper and other pollutants from aqueous medium and soils, consequently cleaning the environment. The aim of this study was, therefore, to investigate the influence of different copper compounds (Cu(II) as CuCl2; Cu(II) as CuSO4; and Cu(I) as CuCl) on copper bioreduction and biosorption using four copper-resistant bacteria isolated from the rhizosphere of two plants (Avena sativa and Plantago lanceolata) in aqueous matrix. Copper resistance profile, bioreduction, and biosorption after 48 h of incubation were evaluated. The isolates displayed high copper resistance. However, isolate A1 did not grow very well in the CuCl2 and isolate T5 was less resistant to copper in aqueous solutions amended with CuCl (Cu(I)). The best copper source for copper bioreduction and biosorption was CuSO4 and the isolates removed as much as ten times more copper than in aqueous solutions amended with the other copper compounds. Moreover, Cu(I) did not succumb to biosorption, although the microbes were resistant to aqueous solutions of CuCl. In summary, Cu(II) from CuSO4 was furthermost susceptible to bioreduction and biosorption for all isolates. This is an indication that copper contamination of the environment from the use of CuSO4 as an agrochemical is amenable to bioremediation. PMID:23417495

  11. Metallurgy and performance of electrodeposited copper for flexible circuits

    Microsoft Academic Search

    H. D. Merchant; J. T. Wang; L. A. Giannuzzi; Y. L. Liu

    2000-01-01

    In this paper, we consider intrinsic properties of copper electrodeposited as plateup on polyimide substrate, thermal response of electrodeposited copper and fatigue performance of copper and copper\\/polyimide construction. The critical material characteristics examined are grain morphology and structure, crystallographic texture, microhardness, uniaxial strength and ductility and isothermal cyclic fatigue life. Given optimum processing conditions, copper plateup in flexible circuits displays

  12. Characteristics and antimicrobial activity of copper-based materials

    Microsoft Academic Search

    Bowen Li

    2008-01-01

    In this study, copper vermiculite was synthesized, and the characteristics, antimicrobial effects, and chemical stability of copper vermiculite were investigated. Two types of copper vermiculite materials, micron-sized copper vermiculite (MCV) and exfoliated copper vermiculite (MECV), are selected for this research. Since most of the functional fillers used in industry products, such as plastics, paints, rubbers, papers, and textiles prefer micron-scaled

  13. 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

  14. 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

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

    Microsoft Academic Search

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

    2010-01-01

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

  16. Mobility and Availability of Copper in Agricultural Soils Irrigated from Water Treated with Copper Sulfate Algaecide

    Microsoft Academic Search

    D. Salam; M. El-Fadel

    2008-01-01

    In this paper, downward movement and availability of copper in soils irrigated with CuSO4 algaecide treated water were examined using column leaching experiments. Two simulations considering 1 and 10 years irrigation\\u000a period were conducted at copper application rate of about 18.7 kg CuSO4\\/ha\\/year. Effluent copper concentrations and vertical distribution of acid and DTPA-extractable copper in the soil columns\\u000a were determined. Nearly 99%

  17. 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

  18. Thermodynamic study of solid copper–nickel alloys by use of copper–beta-alumina

    Microsoft Academic Search

    Toshio Oishi; Shinya Tagawa; Soichiro Tanegashima

    2005-01-01

    Copper–??-alumina was prepared by ion exchange reactions starting with a sodium–??-alumina. Exchange from sodium ion to copper ion was done by immersing the sample in liquid cuprous chloride. Exchange of Na+ ion in ??-alumina to Cu+ ion was not complete as Na+ ion remained within the ??-alumina.Copper activity in solid copper–nickel alloys was measured by electromotive force (EMF) technique incorporating

  19. Copper-graphite materials with copper-clad graphite granule additions

    Microsoft Academic Search

    V. I. Pavlenko; A. A. Zaporozhets; N. S. Dyadenko

    1973-01-01

    In this article, the results are presented of investigations into the antifriction properties of copper base sintered materials with additions of copper-clad graphite granules. Copper-graphite materials are used mainly for sliding electrical contacts, i.e., brushes of electrical machines and inserts for current collectors of electrical vehicles. The performance of copper-graphite sliding contacts is strongly affected by their rubbing speed, applied

  20. 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.

  1. Copper intake and health threat by consuming seafood from copper-contaminated coastal environments in Taiwan

    Microsoft Academic Search

    Bor-cheng Han; Woei-Lih Jeng; Tsu-Chang Hung; Ming-Shiou Jeng

    1994-01-01

    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

  2. Copper Accumulation in a Reservoir Ecosystem Following Copper Sulfate Treatment (St. Germain Les Belles, France)

    Microsoft Academic Search

    Eric van Hullebusch; Philippe Chatenet; Véronique Deluchat; Philippe M. Chazal; Didier Froissard; Michel Botineau; Axel Ghestem; Michel Baudu

    2003-01-01

    Copper sulfate (CuSO4) addition to freshwater for phytoplankton control has been practiced for decades, and remains the most effective algicidal treatment for numerous managed water bodies. A reservoir in the centre of France was the site for an investigation of copper distribution in aquatic systems after a copper sulfate treatment. Results of monitoring showed a rapid conversion of dissolved Cu

  3. Void formation in irradiated copper, nickel and copper-nickel alloys

    Microsoft Academic Search

    J. L. Brimhall; H. E. Kissinger

    1972-01-01

    The formation of voids during neutron irradiation of pure nickel, pure copper and nickel-copper alloys has been studied. Part I concerns the fluence dependence of void parameters in pure copper and nickel irradiated at 285 °C and at very low fluences. The void swelling at these low fluences is not a linear function of the fluence, but varies approximately as

  4. The copper plating of graphite powders in the manufacture of copper-graphite materials

    Microsoft Academic Search

    V. I. Pavlenko

    1976-01-01

    The results are presented of a study of the deposition of copper on graphite powders and of a comparison of chemical and combined (chemical + electrolytic) copper deposition processes. The combined process gives an appreciable saving of copper, improves the qualify of the deposit, and facilitates control of the deposit thickness.

  5. Pyrometallurgical Preconcentration Technique for the Recovery of Copper, Nickel and Cobalt from Copper Converter Slag

    Microsoft Academic Search

    S. MOOKHERJEE; A. A. GADKARI; D. M. DEO; A. GOSWAMI

    1992-01-01

    Laboratory trials of reduction-smelting of copper converter slag of M\\/s Hindustan Copper Limited, Ghatsila to preconcentrate the nonferrous metal values into a metallic alloy form gave an indication for its utility as a pretreatment for a subsequent hydrometallurgical processing to separate the individual metals. Although electric slag cleaning furnaces are prevalent in many copper industries, it was decided to investigate

  6. A novel copper=polydimethiylsiloxane nanocomposite for copper-containing intrauterine contraceptive devices

    E-print Network

    Zheng, Yufeng

    availability, copper- containing intrauterine devices (Cu-IUD) is an increasingly used long-acting reversible to relate to the cupric ion burst release behavior of the copper content of the IUD. In addition, the low throughout the usage of the Cu-IUD by improving either the corrosion performance of the copper content

  7. Radioactivity at the Copper Creek copper lode prospect, Eagle district, east-central Alaska

    USGS Publications Warehouse

    Wedow, Helmuth; Tolbert, Gene Edward

    1952-01-01

    Investigation of radioactivity anomalies at the Copper Creek copper lode prospect, Eagle district, east-central Alaska, during 1949 disclosed that the radioactivity is associated with copper mineralization in highly metamorphosed sedimentary rocks. These rocks are a roof pendant in the Mesozoic "Charley River" batholith. The radioactivity is probably all due to uranium associated with bornite and malachite.

  8. Synthetic Fluorescent Probes for Monovalent Copper

    PubMed Central

    Fahrni, Christoph J.

    2013-01-01

    Fluorescent probes are powerful and cost-effective tools for the detection of metal ions in biological systems. Compared to non-redox-active metal ions, the design of fluorescent probes for biological copper is challenging. Within the reducing cellular environment, copper is predominantly present in its monovalent oxidation state; therefore, the design of fluorescent probes for biological copper must take into account the rich redox and coordination chemistry of Cu(I). Recent progress in understanding the underlying solution chemistry and photophysical pathways led to the development of new probes that offer high fluorescence contrast and excellent selectivity towards monovalent copper. PMID:23769869

  9. 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

  10. 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.

  11. Copper Electroforming at the Canfranc Underground Laboratory. Status Report

    Microsoft Academic Search

    S. Borjabad; J. Amare´; J. Morales; A. Ortiz de Solo´rzano; J. A. Villar

    2007-01-01

    A brief summary of the copper electroforming process is given. The process parameters tuning to attain a copper part with the required characteristics is explained. Several electroformed copper parts with complicated geometry are described. Some radiopurity measurements are provided.

  12. Copper Electroforming at the Canfranc Underground Laboratory. Status Report

    SciTech Connect

    Borjabad, S.; Amare, J.; Morales, J.; Ortiz de Solorzano, A.; Villar, J. A. [Laboratorio de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain)

    2007-03-28

    A brief summary of the copper electroforming process is given. The process parameters tuning to attain a copper part with the required characteristics is explained. Several electroformed copper parts with complicated geometry are described. Some radiopurity measurements are provided.

  13. Copper Electroforming at the Canfranc Underground Laboratory. Status Report

    NASA Astrophysics Data System (ADS)

    Borjabad, S.; Amaré, J.; Morales, J.; Ortiz de Solórzano, A.; Villar, J. A.

    2007-03-01

    A brief summary of the copper electroforming process is given. The process parameters tuning to attain a copper part with the required characteristics is explained. Several electroformed copper parts with complicated geometry are described. Some radiopurity measurements are provided.

  14. 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...

  15. Chromated Copper Arsenate (CCA): Inorganic Arsenical Pressure-Treated Wood

    MedlinePLUS

    ... Information Sheet: Inorganic Arsenical Pressure-Treated Wood Chromated Copper Arsenate (CCA): Consumer Safety Information Sheet: Inorganic Arsenical ... Web page está disponible en español [Including Chromate Copper Arsenate (CCA), Ammoniacal Copper Arsenate (ACA), and Ammoniacal ...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 21 CFR 862.1190 - Copper test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Test Systems § 862.1190 Copper test system. (a) Identification. A copper test system is a device intended to measure copper...hereditary disease primarily of the liver and nervous system). Test results are also used in...

  1. 21 CFR 862.1190 - Copper test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Test Systems § 862.1190 Copper test system. (a) Identification. A copper test system is a device intended to measure copper...hereditary disease primarily of the liver and nervous system). Test results are also used in...

  2. 21 CFR 862.1190 - Copper test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Test Systems § 862.1190 Copper test system. (a) Identification. A copper test system is a device intended to measure copper...hereditary disease primarily of the liver and nervous system). Test results are also used in...

  3. 21 CFR 862.1190 - Copper test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Test Systems § 862.1190 Copper test system. (a) Identification. A copper test system is a device intended to measure copper...hereditary disease primarily of the liver and nervous system). Test results are also used in...

  4. SURVIVAL AND IMMUNE RESPONSE OF COHO SALMON EXPOSED TO COPPER

    EPA Science Inventory

    Vaccination with Vibrio anguillarum by oral administration during copper exposure and intraperitoneal injection prior to copper exposure was employed to investigate the effects of copper upon survival and the immune response of juvenile coho salmon (Oncorhynchus kisutch). Followi...

  5. Dietary copper intake influences skin lysyl oxidase in young men

    Microsoft Academic Search

    Moshe J. Werman; Sam J. Bhathena; Judith R. Turnlund

    1997-01-01

    The effect of low dietary copper on copper status and the copper-containing enzyme lysyl oxidase was studied in young men. The study was divided into three dietary periods. During the first period, subjects were fed 0.66 mg\\/day Cu for 24 days (marginal copper). The level of copper was dropped to 0.38 mg\\/day for the next 42 days (low copper) and

  6. Title. ATP7B copper-regulated traffic and association with the tight junctions: copper excretion into Short title. ATP7B and copper excretion by liver

    E-print Network

    Boyer, Edmond

    1 Title. ATP7B copper-regulated traffic and association with the tight junctions: copper excretion into the bile Short title. ATP7B and copper excretion by liver Authors. Sonia Hernandez*§ , Yo Tsuchiya manuscript Gastroenterology 2008;134(4):1215-23 #12;2 Abstract The copper transporter ATP7B plays a central

  7. Electrochemical nucleation and growth of copper

    NASA Astrophysics Data System (ADS)

    Radisic, Aleksandar

    2005-12-01

    The primary goal of this dissertation is to provide more insight into nucleation and growth processes during electrochemical deposition of copper on various metallic and semiconductor substrates. Electrodeposition is the current method used in forming copper interconnects in integrated circuits, primarily due to the ability of this technique to fill high aspect ratio features with complex geometries at high deposition rates, leading to high throughput and lower manufacturing costs. Important processing steps prior to electroplating involve the deposition of a thin diffusion barrier layer, to prevent copper diffusion into silicon, and deposition of a copper seed layer by means of physical vapor deposition (PVD). The copper seed layer provides good electrical contact and improved adhesion to the diffusion barrier layer. As the feature sizes in integrated circuits continue to decrease, industry is forced to explore the possibility of electrochemical deposition of high quality copper films without the use of a copper seed layer. It is not a priori clear that copper films deposited on diffusion barriers will follow the same growth mode as copper films deposited on copper seed layers, and whether it will be possible to achieve the "superfilling" effects without the copper seed layer. The growth of copper films on diffusion barrier materials occurs through Volmer-Weber (3D island) mode of growth. As a result, high nucleus densities are essential in depositing continuous thin films. For complex structures with small length scales, such as trenches and vias in integrated circuits, a detailed understanding of nucleation and growth, and the influence of parameters such as potential and solution chemistry on the deposition mechanism is critical in designing processes for obtaining the void-free features. The goal of our research is to improve the understanding of the electrochemical nucleation and growth processes necessary for successful electrodeposition of copper onto diffusion barrier layers, e.g. TiN, Ta, or TaN. The mechanism of nucleation and growth of copper from different plating solutions is studied using cyclic voltammetry and chronoamperometry. Deposited films are characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), in-situ, real-time, transmission electron microscopy (TEM). Using the results from these experiments we will optimize procedures for electrodeposition of continuous, high quality copper films on diffusion barrier layers.

  8. 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.

  9. Synthesis of Commercial Products from Copper Wire-Drawing Waste

    NASA Astrophysics Data System (ADS)

    Ayala, J.; Fernández, B.

    2014-06-01

    Copper powder and copper sulfate pentahydrate were obtained from copper wire-drawing scale. The hydrometallurgical recycling process proposed in this article yields a high-purity copper powder and analytical grade copper sulfate pentahydrate. In the first stage of this process, the copper is dissolved in sulfuric acid media via dismutation of the scale. In the second stage, copper sulfate pentahydrate is precipitated using ethanol. Effects such as pH, reaction times, stirring speed, initial copper concentration, and ethanol/solution volume ratio were studied during the precipitation from solution reaction. The proposed method is technically straightforward and provides efficient recovery of Cu from wire-drawing scale.

  10. Energy and materials flows in the copper industry

    SciTech Connect

    Gaines, L.L.

    1980-12-01

    The copper industry comprises both the primary copper industry, which produces 99.9%-pure copper from copper ore, and the secondary copper industry, which salvages and recycles copper-containing scrap metal to extract pure copper or copper alloys. The United States uses about 2 million tons of copper annually, 60% of it for electrical applications. Demand is expected to increase less than 4% annually for the next 20 years. The primary copper industry is concentrated in the Southwest; Arizona produced 66% of the 1979 total ore output. Primary production uses about 170 x 10/sup 12/ Btu total energy annually (about 100 x 10/sup 6/ Btu/ton pure copper produced from ore). Mining and milling use about 60% of the total consumption, because low-grade ore (0.6% copper) is now being mined. Most copper is extracted by smelting sulfide ores, with concomitant production of sulfur dioxide. Clean air regulations will require smelters to reduce sulfur emissions, necessitating smelting process modifications that could also save 20 x 10/sup 12/ Btu (10 x 10/sup 6/ Btu/ton of copper) in smelting energy. Energy use in secondary copper production averages 20 x 10/sup 6/ Btu/ton of copper. If all copper products were recycled, instead of the 30% now salvaged, the energy conservation potential would be about one-half the total energy consumption of the primary copper industry.

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

    Microsoft Academic Search

    Bryan Webler; Lan Yin; Seetharaman Sridhar

    2008-01-01

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

  12. Geomorphology of the lower Copper River, Alaska

    USGS Publications Warehouse

    Brabets, Timothy P.

    1997-01-01

    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 1995, 11 bridges were located along this section of the highway. These bridges cross parts 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. When the outflow rate from Van Cleve Lake reaches it peak, the flow of the Copper River will increase between 150,000 to 190,000 cubic feet per second. Data collected by bedload sampling and continuous seismic reflection indicated 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 Lake, 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. However, 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.

  13. 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.

  14. Tear copper and its association with liver copper concentrations in six adult ewes.

    PubMed Central

    Schoster, J V; Stuhr, C; Kiorpes, A

    1995-01-01

    Tear and liver copper concentrations from 6 clinically healthy adult mixed-breed ewes were measured by Atomic Absorption Electrothermal Atomization (graphite furnace) Spectrometry and Flame Absorption Spectrometry, respectively, 7 times over 227 d to determine if their tears contained copper and if so, whether tear copper concentrations could reliably predict liver copper concentrations. To produce changes in liver copper concentration, the diet was supplemented with copper at concentrations that increased from 23 mg to 45 mg Cu/kg feed/day/sheep during the study. This regimen raised liver copper for all sheep to potentially toxic hepatic tissue concentration of greater than 500 mg/kg dry (DM) matter (tissue). The results of the study showed that copper was present in the tears of all sheep. The mean tear copper concentration showed a positive correlation with liver copper concentration (P = 0.003), increasing from 0.07 mg/kg DM at the start to 0.44 mg/kg DM at the end of the study, but could not reliably predict liver copper concentration (R2 = 0.222). PMID:7648525

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

    PubMed

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

    2009-10-01

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

  16. Potentially novel copper resistance genes in copper-enriched activated sludge revealed by metagenomic analysis.

    PubMed

    Li, Li-Guan; Cai, Lin; Zhang, Xu-Xiang; Zhang, Tong

    2014-12-01

    In this study, we utilized the Illumina high-throughput metagenomic approach to investigate diversity and abundance of both microbial community and copper resistance genes (CuRGs) in activated sludge (AS) which was enriched under copper selective stress up to 800 mg/L. The raw datasets (~3.5 Gb for each sample, i.e., the copper-enriched AS and the control AS) were merged and normalized for the BLAST analyses against the SILVA SSU rRNA gene database and self-constructed copper resistance protein database (CuRD). Also, the raw metagenomic sequences were assembled into contigs and analyzed based on Open Reading Frames (ORFs) to identify potentially novel copper resistance genes. Among the different resistance systems for copper detoxification under the high copper stress condition, the Cus system was the most enriched system. The results also indicated that genes encoding multi-copper oxidase played a more important role than those encoding efflux proteins. More significantly, several potentially novel copper resistance ORFs were identified by Pfam search and phylogenic analysis. This study demonstrated a new understanding of microbial-mediated copper resistance under high copper stress using high-throughput shotgun sequencing technique. PMID:25081552

  17. Inborn errors of copper metabolism

    PubMed Central

    KALER, STEPHEN G.

    2014-01-01

    SUMMARY Wilson disease, Menkes disease, occipital horn syndrome, and X-linked distal hereditary motor neuropathy are genetic disorders of copper metabolism that span a broad spectrum of neurological dysfunction (Table 180.1). The occurrence of these disorders indicates the fundamental importance of ATP7A and ATP7B. Further research to clarify the mechanisms suggested by these clinical and biochemical phenotypes may yield insight about the roles of ATP7A and ATP7B in neuronal cells, and lead to improved treatments. PMID:23622398

  18. The distribution of copper in neonatal mottled mutant mice after exposure to copper and penicillamine

    SciTech Connect

    Hunt, D.M.; Port, A.E.

    1982-08-01

    Tissue copper levels of brindled (Mo/sup br/) mice and normal littermates after single and repeated dosing with CuCl/sub 2/ and/or D-penicillamine are examined, together with a study of the cytosol distribution of copper after CuCl/sub 2/ treatment. The results confirm that the mutant mouse kidney is capable of extensive copper accumulation in association with the low MW copper-binding protein. Deficient tissues such as brain, heart and spleen are able to sequester sufficient of the exogenous copper to raise their levels to the normal control level, whereas mutant liver levels, even after copper treatment, remain below normal, indicating that the Mo gene affects the ability of the liver to retain copper.

  19. Treatment of Wilson's disease with zinc. II. Validation of oral /sup 64/copper with copper balance

    SciTech Connect

    Hill, G.M.; Brewer, G.J.; Juni, J.E.; Prasad, A.S.; Dick, R.D.

    1986-12-01

    The efficacy of zinc as a therapeutic agent to control copper balance in Wilson's disease patients has been previously documented with balance studies. In an attempt to develop a simpler and faster tool for evaluating the adequacy of zinc therapy, a technique that measures the uptake into blood of a small oral dose of /sup 64/copper was studied in conjunction with copper balance. The mean peak /sup 64/copper uptake into blood of nine Wilson's disease patients on D-penicillamine, trien, or no medication was 6.04 +/- 2.74%, comparable with normal controls. Seven patients on zinc therapy had a markedly and significantly reduced mean uptake of 0.79 +/- 1.05% after treatment. The data demonstrate that the prevention of copper uptake into blood in Wilson's disease patients by zinc therapy can be evaluated by /sup 64/copper uptake and that peak uptakes of less than 1% occur in patients with neutral or negative copper balance.

  20. POLLUTION ABATEMENT IN A COPPER WIRE MILL

    EPA Science Inventory

    This Capsule Report shows how water consumption in copper wire mills can be reduced by 90%. The reduction was from 200,000 gallons per day to 20,000 gallons per day by chemical rinsing and water reuse. The sulfuric acid pickle was regenerated and high purity metallic copper recov...

  1. Acute toxicity of copper to mediterranean dogfish.

    PubMed

    Torres, P; Tort, L; Flos, R

    1987-01-01

    Acute copper toxicity to dogfish (Scyliorhinus canicula) was determined. Median lethal concentrations (LC50) for 24 and 48 hr were respectively 16 and 4 mg/l. These results are compared with those for zinc in dogfish and with the values for copper toxicity in several teleosts obtained by other authors. PMID:2881713

  2. 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

  3. 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 ...

  4. Fractionation of elements during copper smelting

    Microsoft Academic Search

    Mark S. Germani; W. H. Zoller; M. Small; Jarvis L. Moyers

    1981-01-01

    A recent study of the elemental composition of particulate material collected from the plumes of five copper smelters in southeastern Arizona indicated that arsenic, lead, selenium, cadmium, zinc, tungsten, indium, and other chalcophilic elements are highly enriched in the plume materials relative to the background aerosol. Enrichments are due to the volatilization of these elements during copper smelting. Significant differences

  5. 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...

  6. 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

  7. Application of INKORAM-75 copper corrosion inhibitor

    NASA Astrophysics Data System (ADS)

    Galanin, A. V.; Fedorov, A. I.; Kucherenko, O. V.; Gromov, A. F.

    2014-02-01

    Treatment of cooling water with INKORAM-75 copper corrosion inhibitor is applied for reducing corrosion processes in the copper-containing alloy of which turbine condensers are made. The results obtained from industrial trial of the INKORAM-75 inhibitor in the service cooling water system of the Novovoronezh NPP Units 3 and 4 are presented.

  8. NON-UNIFORM COPPER CORROSION: RESEARCH UPDATE

    EPA Science Inventory

    Pinhole leaks due to copper pitting corrosion are a major cause of home plumbing failure. This study documents cases of copper pitting corrosion found in homes supplied by Butler County Environmental Services in Ohio. SEM. XRD, and optical microscopy were used to document pit s...

  9. Fetal polyol metabolism in copper deficiency

    SciTech Connect

    Fields, M.; Lewis, C.G.; Beal, T. (Georgetown Univ. Medical Center, Washington, DC (USA))

    1989-02-09

    Since pregnant rats consuming fructose, copper deficient diets fail to give birth, the relationship between maternal copper deficiency, polyol metabolism and fetal mortality was investigated. Forty Sprague-Dawley rats were fed from conception one of the following diets: fructose, copper deficient; fructose, copper adequate; starch, copper deficient or starch, copper adequate. The deficient diets contained 0.6 ug Cu and the adequate 6.0 ug Cu/g diet. Pregnancy was terminated at day 19 of gestation. Glucose, sorbitol and fructose were measured in maternal blood, placenta and fetal liver. Fructose consumption during pregnancy resulted in higher levels of fructose and sorbitol in maternal blood when compared to starch. In the fructose dietary groups, the placenta and fetal liver contained extremely high levels of glucose, fructose and sorbitol compared to the corresponding metabolites from the starch dietary groups. Copper deficiency further elevated fructose and sorbitol concentrations in the placenta and fetal liver respectively. Since high tissue levels of glucose, fructose and sorbitol have been shown to have deleterious effects on cellular metabolism, these data suggest that when fructose was fed during pregnancy the combination of an aberration of carbohydrate metabolism with copper deficiency could be responsible for the pathology and mortality of the developing fetus.

  10. Lead and Copper Control 101-slides

    EPA Science Inventory

    This presentation is an overview of the most important water treatment strategies for the control of lead and copper release from drinking water corrosion. In addition to the sections specifically on lead and copper treatment, sections are included that cover sampling to find le...

  11. Effects of copper on phagocytosis in Tetrahymena

    Microsoft Academic Search

    Jytte R. Nilsson

    1981-01-01

    Summary Addition of copper, corresponding to 100 ppm, to the normal 2% proteose peptone medium is tolerated byTetrahymena. This concentration of copper stimulates phagocytosis to a maximum value which is reached gradually during the first 1 hour exposure, and which is maintained during continuous exposures. Cell proliferation is resumed after a lag period, although at a decreased rate. Cells exposed

  12. Reactivity studies of plasma-synthesized aluminum trifluoride and electrochemical synthesis of non-stoichiometric silver selenide nanowire arrays

    NASA Astrophysics Data System (ADS)

    Hajime, Evan Koon Lun Yuuji

    A high surface area aluminum trifluoride material ("plasma-AIF3 ") has previously been synthesized in our laboratory by decomposition of zeolitic precursors in fluorine-containing, low-temperature plasmas. The characterization of the halogen exchange reactivity of this unique fluoride material is presented in Part 1 of the dissertation. A gas flow reactor was designed and built to study the isothermal and temperature-dependent halogen exchange activity of plasma-AIF3, with comparisons being made to the well-known halogen exchange catalyst beta-AIF3. Isothermal experiments showed that plasma-AIF3 is an active halogen exchange catalyst for the dismutation of dichlorodifluoromethane, while temperature-programmed reaction (TPR) experiments revealed a lower temperature onset of activity with plasma-AIF3 when compared to beta-AIF3. The existence of two distinct active sites for halogen exchange on aluminum fluoride is proposed, with sites characteristic of plasma-AIF3 and R-AIF3 having lower and higher temperature onsets of activity, respectively. TPR data for hydrated plasma-AIF3 showed a significant attenuation of the lower temperature active sites, while the higher temperature site remained relatively unchanged in activity. Temperature-programmed X-ray diffraction of plasma-AIF3 revealed the existence of beta-AIF 3 crystallites at temperatures between 225 and 500°C, thus rationalizing the existence of the higher temperature active site (associated with beta-AIF 3) in plasma-AIF3 during heating. Plasma-AIF3 also displayed a high affinity for crystalline hydrate formation with extended exposure to moist air, and TPR experiments performed on commercially available AIF3·3H2O produced plots similar in shape and features when compared to plasma-AIF3. The thermal transformation processes of the trihydrate suggest the origin of the lower temperature active site to be associated with an amorphous bulk AIF3 structure. Part 2 of the dissertation summarizes the current efforts made toward the template-assisted electrodeposition of Ag2+deltaSe nanowire arrays for fundamental and exploratory studies of the magnetoresistance in non-stoichiometric silver chalcogenides. Silver selenide can be difficult to electrodeposit due in part to the highly facile plating of silver metal from aqueous solutions. A new electrodeposition solution is proposed, containing AgNO3 and SeCl4 as the metal precursors, dimethyl sulfoxide (DMSO) as the solvent and tetrabutylammonium chloride (TBACl) as a supporting electrolyte. The electrodeposition of Ag2Se from this solution and a previously reported solution using NaNO3 as supporting electrolyte was investigated using cyclic voltammetry and X-ray diffraction analysis of electrodeposited thin films. Cyclic voltammograms of solutions containing only AgNO3 and TBACl in DMSO showed one redox couple corresponding to the deposition and stripping of Ag metal, while the NaNO3-based solution showed an additional redox couple believed to involve the generation of negatively-charged Ag nanoparticles. Thin film electrodeposition of Ag metal from DMSO-based solutions produced non-dendritic deposits, and may be a useful alternative bath solvent for the silver plating industry. Solutions containing only SeCl 4 and TBACl in DMSO were studied by cyclic voltammetry, and revealed important potential ranges within which elemental Se is stable with respect to oxidation and reduction. The proposed mixed-metal electrodeposition solution was also analyzed with cyclic voltammetry, and the reductive formation of Ag2Se was found to occur at potentials between -0.55 V and -0.70 V (vs. Pt/0.1 M Nal, 0.05 M I2 (DMSO)). Using the results from the electroanalysis of the electrodeposition solutions, nanowire arrays of Ag2+deltaSe were successfully grown by electrodeposition into porous alumina membranes at room temperature (22°C) using an applied voltage of -0.70 V (vs. Pt/0.1 M Nal, 0.05 M I2 (DMSO)). Scanning electron microscopy showed smooth and continuous nanowires of 50 and 100 nm diameters and up to lengths of 25 mum. Electro

  13. 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

  14. Effects of pattern characteristics on copper CMP

    NASA Astrophysics Data System (ADS)

    Wenbiao, Ruan; Lan, Chen; Zhigang, Li; Tianchun, Ye

    2009-04-01

    Copper chemical mechanical polishing (CMP) is influenced by geometric characteristics such as line width and pattern density, as well as by the more obvious parameters such as slurry chemistry, pad type, polishing pressure and rotational speed. Variations in the copper thickness across each die and across the wafer can impact the circuit performance and reduce the yield. In this paper, we propose a modeling method to simulate the polishing behavior as a function of layout pattern factors. Under the same process conditions, the pattern density, the line width and the line spacing have a strong influence on copper dishing, dielectric erosion and topography. The test results showed: the wider the copper line or the spacing, the higher the copper dishing; the higher the density, the higher the dielectric erosion; the dishing and erosion increase slowly as a function of increasing density and go into saturation when the density is more than 0.7.

  15. Synthesis, crystal structure and electronic properties of the new iron selenide Ba{sub 9}Fe{sub 4}Se{sub 16}

    SciTech Connect

    Berthebaud, David, E-mail: david.berthebaud@ensicaen.fr; Preethi Meher, K.R.S.; Pelloquin, Denis; Maignan, Antoine

    2014-03-15

    The new ternary selenide Ba{sub 9}Fe{sub 4}Se{sub 16} 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 I4{sub 1}/a with a=10.0068(3) Å and c=35.6415(9) Å, Z=4. It is an isostructural compound to the sulfide ?-Ba{sub 9}Fe{sub 4}S{sub 15}, which is a high temperature polymorph of ?-Ba{sub 9}Fe{sub 4}Se{sub 15} that belongs to the indefinitely adaptive phases series Ba{sub 3}Fe{sub 1+x}S{sub 5}, 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 FeSe{sub 4} tetrahedra are found. Magnetic measurements performed on Ba{sub 9}Fe{sub 4}Se{sub 16} 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 T{sub N}. However no magneto dielectric effect was evidenced for magnetic fields of up to 3 T. Activation energy, E{sub A}=0.18 eV, was extracted from the AC conductivity plot in the temperature range of 160–300 K. -- Graphical abstract: Experimental electron diffraction (ED) patterns of Ba{sub 9}Fe{sub 4}Se{sub 16} recorded along a-[010]. Highlights: • A new iron selenide material. • A structure resolution by combination of XRD and TEM. • Magnetic properties of the new compound Ba{sub 9}Fe{sub 4}Se{sub 16} are discussed.

  16. 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

  17. Effect of chelators on copper metabolism and copper pools in mouse hepatocytes

    SciTech Connect

    McArdle, H.J.; Gross, S.M.; Creaser, I.; Sargeson, A.M.; Danks, D.M.

    1989-04-01

    Disorders of copper storage are usually treated by chelation therapy. It is generally thought that the chelators act by mobilizing copper from the liver, hence allowing excretion in the urine. This paper has examined the effect of chelators on copper uptake and storage in mouse hepatocytes. Penicillamine, a clinically important chelator, does not block the uptake of copper or remove copper from hepatocytes. Two other copper chelators, sar and diamsar, which form very stable and kinetically inert Cu2+ complexes by encapsulating the metal ion in an organic cage, were shown to block copper accumulation by the cells and to remove up to 80% of cell-associated copper. They also removed most (approximately 80%) of the /sup 64/Cu accumulated by the cells in 30 min, but released only a small percentage (less than 20%) of that accumulated over 18 h. The results show that copper in the hepatocyte can be divided into at least two pools, an easily accessible one, and another, not removable even after long-term incubation with any of the chelators. Most of the copper normally found in the cell appeared to be associated with the former pool.

  18. Thermal enrichment and speciation of copper in rice husk ashes.

    PubMed

    Wei, Yu-Ling; Hu, Ming-Jan; Peng, Yen-Hsun

    2010-12-15

    Copper(II) was considerably enriched in the residual ash via thermal treatment of copper-sorbed rice husk at 700-1100°C for 2h, and the copper speciation was quantitatively determined with X-ray absorption spectroscopy. After the thermal process, the resulting ash only represents by weight 18.7-26.4% of the pre-heated samples. Copper content in the ashes is >7% which is far above the required minimum copper content in copper ores for the copper smelting sector, 0.5%. Crystalline SiO(2) is observed only in the ash generated at 1100°C, with more copper in this ash being available for leaching in acidic solution. It is suggested that this is due to the considerable dissimilarity in crystalline structure between copper compounds and crystalline SiO(2). No chemical reaction between copper and SiO(2) is observed in any ash. In fact, we suggest that the SiO(2) crystalline phase repels copper during the thermal process; this would make it easy to extract copper from the ashes. For copper speciation in the ashes, CuO merely represents 0-12% of the total copper, while Cu(2)O and Cu(0) represent 34-42% and 46-63%, respectively. The lower copper oxidation state would be beneficial for the copper smelting process due to less usage of coke. PMID:20869164

  19. A mechanistic study of copper electropolishing in phosphoric acid solutions

    Microsoft Academic Search

    Andrew Mansson

    2005-01-01

    The microelectronics industry is using copper as the interconnect material for microchips. A study of copper electropolishing is important for the process development of a new, low downforce approach, which is being developed to replace chemical mechanical polishing (CMP) of the copper overburden. A promising technology is a combination of electropolishing with conventional CMP. Electropolishing of copper in phosphoric acid

  20. Effects of electromigration on copper atoms in carbon nanotube channels

    Microsoft Academic Search

    M. C. G. Lim; Z. W. Zhong

    2011-01-01

    The effects of electromigration on copper in carbon nanotube (CNT) channels are investigated using molecular dynamics simulations. The study shows that the potential energy of copper and the resistive forces on copper are dependent on the shape of the CNT junction, and the increase in bias voltages magnifies these effects. Bias voltages affect the density of copper in the downstream

  1. Dynamical behavior of copper atoms in a carbon nanotube channel

    Microsoft Academic Search

    M. C. G. Lim; Z. W. Zhong

    2011-01-01

    The transportation of copper atoms along a carbon nanotube (CNT) channel, which consists of a junction, is studied using molecular dynamics simulations. A bias voltage is applied along the channel to induce an electromigration force on copper atoms. The study focuses on the flow of copper atoms by varying the voltage gradient and the temperature of copper. The results show

  2. 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...

  3. 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

  4. 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

  5. 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

  6. Ctr6, a Vacuolar Membrane Copper Transporter in Schizosaccharomyces pombe*

    E-print Network

    Labbé, Simon

    is induced under copper-limiting conditions. This regulation is mediated by the cis-acting promoter element CuSE (copper-sig- naling element) through the copper-sensing transcrip- tion factor Cuf1. An S. pombe to the cytosol. Acquisition of copper is crucial for aerobic life, because this element is an essential component

  7. Plated copper on ceramic for power hybrid applications

    Microsoft Academic Search

    R. W. Johnson; D. Hopkins; J. Muir; J. R. Williams

    1989-01-01

    A technique for plating copper onto ceramic with top layers of nickel, gold, and\\/or solder is described. The adhesion mechanism of the copper is an interlocking of the film and ceramic surface to form a mechanical bond. Soldered adhesion of the copper did not degrade during high-temperature storage or thermal cycling. A nickel barrier between the plated copper and solder

  8. Bioinorganic Chemical Modeling of Dioxygen-Activating Copper Proteins.

    ERIC Educational Resources Information Center

    Karlin, Kenneth D.; Gultneh, Yilma

    1985-01-01

    Discusses studies done in modeling the copper centers in the proteins hemocyanin (a dioxygen carrier), tyrosinase, and dopamine beta-hydroxylase. Copper proteins, model approach in copper bioinorganic chemistry, characterization of reversible oxygen carriers and dioxygen-metal complexes, a copper mono-oxygenase model reaction, and other topics are…

  9. Copper toxicosis in a Boer goat.

    PubMed

    Cregar, Laura C; Wiedmeyer, Charles E; Ringen, Davin R; Evans, Tim J; Johnson, Gayle C; Kuroki, Keiichi

    2012-12-01

    A 1-year-old female Boer goat was presented with a 1-day history of pigmenturia, anorexia, and shivering. Anemia was not present initially, but progressive hemolytic anemia developed subsequently and was characterized by the finding of Heinz bodies in both intact RBCs and in ghost cells and the presence of atypical fusiform RBCs. Plasma biochemical analysis revealed increased activities of aspartate aminotransferase and gamma-glutamyltransferase, hyperbilirubinemia, and azotemia. Histopathologic examination of a liver biopsy revealed necrosis of individual hepatocytes and intracytoplasmic rhodamine-positive granules, consistent with copper. Copper concentration in ante-mortem hepatic tissue was increased, and a diagnosis of copper toxicosis was made. Despite supportive therapy, the goat continued to decline and was euthanized. Necropsy findings included hepatic necrosis and hemoglobinuric nephrosis. Freshly collected specimens of liver and kidney had markedly increased copper concentrations. The mineral composition of the water, grass hay, and goat chow was evaluated, and toxins and significant mineral imbalances were not found. The underlying cause of the hepatic accumulation and subsequent release of copper remains unclear in this goat. Recently, Boer goats have been recognized as being prone to copper toxicosis and may be more susceptible than other breeds; similar to sheep, Boer goats may experience a hemolytic crisis secondary to copper toxicosis. PMID:23121408

  10. Normal macrophage function in copper deficient mice

    SciTech Connect

    Lukasewycz, O.A.; Kolquist, K.L.; Prohaska, J.R.

    1986-03-01

    Copper deficiency (-Cu) was produced in C57 BL and C58 mice by feeding a low copper diet (modified AIN-76A) from birth. Mice given supplemental copper in the drinking water (+Cu) served as controls. Copper status was monitored by assay of ceruloplasmin (CP) activity. Macrophages (M0) were obtained from matched +Cu and -Cu male 7 week-old mice by peritoneal lavage 3 days after thioglycollate stimulation. M0 were assayed in terms of lipopolysaccharide-induced hexose monophosphate shunt activity by monitoring /sup 14/CO/sub 2/ production from (1-/sup 14/C)-glucose and by the determination of phagocytic index using fluorescein labelled latex bead ingestion. M0 from -Cu mice were equivalent to those of +Cu mice in both these parameters. However, superoxide dismutase and cytochrome oxidase activities were both significantly lower in -Cu M0, confirming a functional copper deficiency. Previous results from this laboratory have shown that -Cu mice have a decreased antibody response to sheep erythrocyte antigens and a diminished reactivity to B and T cell mitogens. These immunological insufficiencies appear to be proportional to the severity of copper depletion as determined by CP levels. Furthermore, -Cu lymphocytes exhibit depressed mixed lymphocyte reactivity consistent with alterations at the membrane surface. The present results suggest that M0/monocytes are less severely affected than lymphocytes in copper deficiency states.

  11. Machining and mechanical engraving of copper thermal-sprayed coatings

    NASA Astrophysics Data System (ADS)

    Schroeder, M.

    1998-09-01

    Copper rolls and copper thermal spray coated rolls are being used throughout the printing industry. Copper is the material of choice for printing rolls that are subsequently machined, mechanically engraved, and hard chrome plated. However, there are several limitations associated with the application of copper thermal spray coatings, especially onto copper substrates at thicknesses greater than 0.015 in. This article presents thermal spray techniques that will improve the coating quality of copper coatings. These techniques reduce the oxide content, lower the porosity level, and produce a coating with a more desirable hardness range that allows for improved machining and easier mechanical engraving of copper coatings.

  12. 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

  13. Penta­zirconium copper tribismuth

    PubMed Central

    Balinska, Agnieszka; Tarasiuk, Ivan; Pavlyuk, Volodymyr

    2013-01-01

    Penta­zirconium copper tribismuth, Zr5CuBi3, crystallizes in the hexa­gonal Hf5CuSn3 structure type. The asymmetric unit contains two Zr sites (site symmetries 3.2 and m2m), one Cu site (site symmetry 3.m) and one Bi site (site symmetry m2m). The environment of the Bi atoms is a tetra­gonal anti­prism with one added atom and a coordination number (CN) of 9. The polyhedron around the Zr1 atom is a defective cubo­octa­hedron with CN = 11. The bicapped hexa­gonal anti­prism (CN = 14) is typical for Zr2 atoms. The Cu atom is enclosed in a eight-vertex polyhedron (octa­hedron with two centered faces). The metallic type of bonding was indicated by an analysis of the inter­atomic distances and electronic structure calculation data. PMID:24109256

  14. Copper-Exchanged Zeolite L Traps Oxygen

    NASA Technical Reports Server (NTRS)

    Sharma, Pramod K.; Seshan, Panchalam K.

    1991-01-01

    Brief series of simple chemical treatments found to enhance ability of zeolite to remove oxygen from mixture of gases. Thermally stable up to 700 degrees C and has high specific surface area which provides high capacity for adsorption of gases. To increase ability to adsorb oxygen selectively, copper added by ion exchange, and copper-exchanged zeolite reduced with hydrogen. As result, copper dispersed atomically on inner surfaces of zeolite, making it highly reactive to oxygen, even at room temperature. Reactivity to oxygen even greater at higher temperatures.

  15. Titanium diboride copper-matrix composites

    Microsoft Academic Search

    P. YIH; D. D. L CHUNG

    1997-01-01

    Copper-matrix titanium diboride platelet (3–5 ?m) composites containing 15–60 vol% TiB2, were fabricated by powder metallurgy,\\u000a using copper-coated TiB2 (60 vol% TiB2) and various amounts of copper powder. The porosity was ?0.5% when TiB2 was ?48 vol%.\\u000a Above 48 vol% TiB2, the porosity increased abruptly with increasing TiB2 content, reaching 6.7% at 60 vol% TiB2. As a result,\\u000a the hardness

  16. Copper leaching, solvent extraction, and electrowinning technology

    SciTech Connect

    Jergensen, G.V. II [ed.

    1999-07-01

    This volume recognizes the growing role of solvent extraction and electrowinning technology in the global copper business. This process is an efficient and cost effective way to extract copper. This proceedings documents the present status of the SX-EW business. It represents a substantial body of historical, scientific, engineering, and commercial information regarding the growth and application of the technology. Sections include: the business and technology of SX-EW, theory and practice of copper leaching, theory and practice of tankhouse operations, and theory and practice of solvent extraction.

  17. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierrae from California

    USGS Publications Warehouse

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour. Copyright ?? 2011 British Lichen Society.

  18. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierra from California

    USGS Publications Warehouse

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour.

  19. 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.

  20. Thermo-optical characterization of cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dots embedded in biocompatible materials.

    PubMed

    Pilla, Viviane; Alves, Leandro P; Iwazaki, Adalberto N; Andrade, Acácio A; Antunes, Andrea; Munin, Egberto

    2013-09-01

    Cadmium selenide/zinc sulfide (CdSe/ZnS) core-shell quantum dots (QDs) embedded in biocompatible materials were thermally and optically characterized with a thermal lens (TL) technique. Transient TL measurements were performed with a mode-mismatched, dual-beam (excitation and probe) configuration. A thermo-optical study of the CdSe/ZnS QDs was performed for different core diameters (3.5, 4.0, 5.2, and 6.6 nm) in aqueous solution and synthetic saliva, and three different core diameters (2.4, 2.9, and 4.1 nm) embedded in restorative dental resin (0.025% by mass). The thermal diffusivity results are characteristic of the biocompatible matrices. The radiative quantum efficiencies for aqueous solution and biofluid materials are dependent on the core size of the CdSe/ZnS core-shell QDs. The results obtained from the fluorescence spectral measurements for the biocompatible materials support the TL results. PMID:24067629

  1. 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.

  2. 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

  3. Pool Boiling Performance Comparison of Smooth and Sintered Copper Surfaces with and Without Carbon Nanotubes

    Microsoft Academic Search

    John P. McHale; Suresh V. Garimella; Timothy S. Fisher; Glen A. Powell

    2011-01-01

    Pool boiling heat transfer is measured with two individual working fluids on copper surfaces enhanced with sintered copper powder and carbon nanotubes. The working fluids are a segregated hydrofluoroether, HFE-7300 (3M Electronic Markets Materials Division, St. Paul, MN), and deionized water. The surfaces considered in the experiments include smooth copper, copper with sintered copper particles, smooth copper with copper-coated carbon

  4. 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

  5. Complexation of Copper(I) by Thioamino acids. Implications for copper speciation in blood plasma

    Microsoft Academic Search

    Lan-Chi Tran-Ho; Peter M. May; Glenn T. Hefter

    1997-01-01

    There is mounting evidence that Cu(I) is the most important oxidation state of copper in many physiological systems. Research into Cu(I)-thioamino acid complex formation serves not only to improve the chelation therapy for treating copper intoxication but may also provide a better understanding of many facets of normal copper metabolism. Formation constants for the ternary mixed ligand complexes of Cu(I)

  6. Selective recovery of copper from copper-nickel sulfide concentrates by applying segregation technology

    Microsoft Academic Search

    William R. Opie; Lamar D. Coffin; David L. Armant; Otto F. Cimler

    1979-01-01

    Copper can be selectively segregated from roasted copper-nickel sulfide concentrates. Conditions are reported for desulfurizing-roasting\\u000a followed by segregation treatment to selectively reduce and segregate copper without nickel contamination. A process is described\\u000a which is applicable for treating low grade sulfide concentrates such as are produced in Botswana (4.6 pct Cu, 3.1 pct Ni)\\u000a and higher grade concentrates that can potentially

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

    Microsoft Academic Search

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

    2011-01-01

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

  8. On the kinetics of oxidation of liquid copper and copper-sulfur alloys by carbon dioxide

    Microsoft Academic Search

    C. F. Acton; G. R. Belton

    1976-01-01

    The rates of transfer of oxygen between CO2-CO gas mixtures and liquid copper and copper-sulfur alloys have been studied by a steady-state electrochemical technique.\\u000a For sulfur-free stagnant copper, and under the conditions of the experiments, the rates are shown to be controlled by the\\u000a diffusion of oxygen in the metal. The resulting diffusivities are in close accord with the bulk

  9. Leaching of Copper Sulphides and Copper Mattes in Oxygenated Chloride\\/Sulphate Leachants

    Microsoft Academic Search

    FRANK LAWSON; CHU-YONG CHENG; LISA SIEW YING LEE

    1992-01-01

    The leaching of chalcocite (Cu2S) and copper-lead matte in oxygenated acidic chloride-sulphate leachants at 85°C has been studied.Copper leaches from both materials via a two stage process, the overall reactions beingandThe chloride ions are believed to promote the formation of a crystalline porous sulphur layer on the reacting particle so that essentially complete copper extraction is possible. The same mechanism

  10. Copper-graphite materials with copper-clad graphite granule additions

    Microsoft Academic Search

    L. A. Osvetimskii; N. S. Dyadenko; A. A. Zaporozhets; N. A. Belentsova

    1971-01-01

    1.Sintered copper-graphite materials have been produced containing additions of copper-clad graphite granules.2.The addition of graphite in clad form to copper-graphite materials lowers their electrical resistivity and raises their compressive strength; the presence of more than 6% of clad graphite increase also the hardness and trnasverse rupture strength. Thus, the hardness, compressive strength, and transverse rupture strength of a material with

  11. Electrical conduction in composites containing copper core-copper oxide shell nanostructure in silica gel

    Microsoft Academic Search

    D. Das; T. K. Kundu; M. K. Dey; S. Chakraborty; D. Chakravorty

    2003-01-01

    Composites of nanometre-sized copper core-copper oxide shell with diameters in the range 6.1 to 7.3 nm dispersed in a silica\\u000a gel were synthesised by a technique comprising reduction followed by oxidation of a suitably chosen precursor gel. The hot\\u000a pressed gel powders mixed with nanometre-sized copper particles dispersed in silica gel showed electrical resistivities several\\u000a orders of magnitude lower than

  12. Ordered arrays of copper nanowires enveloped in polyaniline nanotubes

    Microsoft Academic Search

    A. Prun?; V. Brânzoi; F. Brânzoi

    2011-01-01

    Copper nanowires enveloped in polyaniline (PANI) nanotubes were obtained by ‘second order’ electrodeposition into the pores\\u000a of anodic porous alumina. The templated synthesis of copper nanowires was performed by both potentiostatic and galvanostatic\\u000a methods. The morphology of the polyaniline nanotubes, copper nanowires as well as the copper-filled polyaniline nanotubes\\u000a was investigated by means of scanning electron microscopy. The copper nanowires

  13. Managing the Use of Copper-Based Antifouling Paints

    Microsoft Academic Search

    Mridula Srinivasan; Geoffrey W. Swain

    2007-01-01

    Copper is the biocide of choice for present-day antifouling (AF) paints. It is also a major source of copper loading in to\\u000a the marine environment and, as such, might cause local copper levels to exceed water quality criteria. The present study is\\u000a multifaceted and looks into the overall impact of copper-based AF paints on copper concentrations along a 64-km stretch

  14. Electrochemical behaviour of copper-nickel alloy in chloride solution

    Microsoft Academic Search

    J Mathiyarasu; N Palaniswamy; V S Muralidharan

    1999-01-01

    Cyclic voltammetric measurements were made on pure copper, nickel and 70\\/30 copper-nickel alloy in sodium sulphate and sodium\\u000a chloride (0.5 M) solutions. In sodium sulphate solution the passivation of copper and nickel is through oxide formation. The\\u000a passive film on copper nickel alloy is found to have nickel ions ingress along with copper oxide by volume diffusion. Nickel\\u000a ions cause

  15. 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.

  16. 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

  17. Effects of stimulation of copper bioleaching on microbial community in vineyard soil and copper mining waste.

    PubMed

    Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Bortolon, Leandro; Lambais, Márcio R; Camargo, Flávio A O

    2012-04-01

    Long-term copper application in vineyards and copper mining activities cause heavy metal pollution sites. Such sites need remediation to protect soil and water quality. Bioremediation of contaminated areas through bioleaching can help to remove copper ions from the contaminated soils. Thus, the aim of this work was to evaluate the effects of different treatments for copper bioleaching in two diverse copper-contaminated soils (a 40-year-old vineyard and a copper mining waste) and to evaluate the effect on microbial community by applying denaturing gradient gel electrophoresis (DGGE) of 16S ribosomal DNA amplicons and DNA sequence analysis. Several treatments with HCl, H(2)SO(4), and FeSO(4) were evaluated by stimulation of bioleaching of copper in the soils. Treatments and extractions using FeSO(4) and H(2)SO(4) mixture at 30°C displayed more copper leaching than extractions with deionized water at room temperature. Treatment with H(2)SO(4) supported bioleaching of as much as 120 mg kg(-1) of copper from vineyard soil after 115 days of incubation. DGGE analysis of the treatments revealed that some treatments caused greater diversity of microorganisms in the vineyard soil compared to the copper mining waste. Nucleotide Blast of PCR-amplified fragments of 16S rRNA gene bands from DGGE indicated the presence of Rhodobacter sp., Silicibacter sp., Bacillus sp., Paracoccus sp., Pediococcus sp., a Myxococcales, Clostridium sp., Thiomonas sp., a firmicute, Caulobacter vibrioides, Serratia sp., and an actinomycetales in vineyard soil. Contrarily, Sphingomonas was the predominant genus in copper mining waste in most treatments. Paracoccus sp. and Enterobacter sp. were also identified from DGGE bands of the copper mining waste. Paracoccus species is involved in the copper bioleaching by sulfur oxidation system, liberating the copper bounded in the soils and hence promoting copper bioremediation. Results indicate that stimulation of bioleaching with a combination of FeSO(4) and H(2)SO(4) promoted bioleaching in the soils and can be employed ex situ to remediate copper-impacted soils. PMID:21947860

  18. Characteristics and antimicrobial activity of copper-based materials

    NASA Astrophysics Data System (ADS)

    Li, Bowen

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

  19. 21 CFR 73.2647 - Copper powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive copper powder shall conform...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

  20. 21 CFR 73.2647 - Copper powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive copper powder shall conform...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

  1. Molecular dynamics simulation of polycrystalline copper

    NASA Astrophysics Data System (ADS)

    Bolesta, A. V.; Fomin, V. M.

    2014-09-01

    An approach for molecular dynamics simulation of the formation of polycrystalline materials from a melt during its cooling is proposed. Atomic configurations of copper corresponding to polycrystals with the mean grain size from 2 to 16 nm are obtained. Isothermal uniaxial tension and compression of these polycrystals is studied by the molecular dynamics method. For the mean grain size of polycrystalline copper being smaller than 10 nm, it is shown that Young's modulus and yield stress decrease as the grain size decreases. Shock adiabats for polycrystalline copper are constructed. For a material with the grain size approximately equal to 2 nm, the temperature behind the shock wave front is demonstrated to be 10% higher than that in a polycrystal with the grain size greater than 10 nm. Molecular dynamics calculations predict the presence of copper with a body-centered cubic lattice behind the shock wave front at pressures ranging from 100 to 200 GPa.

  2. 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.

  3. Copper-Catalyzed Trifluoromethylation of Unactivated Olefins

    E-print Network

    Parsons, Andrew T.

    Activating the inactive: A copper-catalyzed allylic trifluoromethylation of unactivated terminal olefins proceeds under mild conditions to produce linear allylic trifluoromethylated products with high E/Z selectivity (see ...

  4. 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 ...

  5. 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 ...

  6. 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.

  7. Minerals and Trace Elements Copper Uptake and Retention in Liver Parenchymal Cells Isolated from Nutritionally! Copper-Deficient Rats

    Microsoft Academic Search

    GERRIT J. VANDENBERG; JEROEN J. M. DE; INGRID BOCK; MARION J. J. GLJBELS; K. Y. LEI

    Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (< 1 mg Cu\\/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver, anemia, low plasma ceruloplasmin oxidase activity and increased MCu whole-body retention. Freshly isolated liver paren chyma!

  8. Diamine Ligands in Copper-Catalyzed Reactions

    PubMed Central

    Surry, David S.

    2012-01-01

    The utility of copper-mediated cross-coupling reactions has been significantly increased by the development of mild reaction conditions and the ability to employ catalytic amounts of copper. The use of diamine-based ligands has been important in these advances and in this review we discuss these systems, including the choice of reaction conditions and applications in the synthesis of pharmaceuticals, natural products and designed materials. PMID:22384310

  9. Average power scaling of copper hybrid lasers

    Microsoft Academic Search

    L. Little; Chris E. Little

    1997-01-01

    Copper lasers are the highest efficiency high average power visible lasers (510.6 and 578.2 nm). The most efficient of them all is the copper hybrid laser, which has been demonstrated to produce 200 W average power with 1.9% efficiency. The prospects for increasing the average output power from single or double tube devices into the kilowatt regime are discussed. With

  10. Copper mercaptides as sulfur dioxide indicators

    DOEpatents

    Eller, Phillip G. (Los Alamos, NM); Kubas, Gregory J. (Los Alamos, NM)

    1979-01-01

    Organophosphine copper(I) mercaptide complexes are useful as convenient and semiquantitative visual sulfur dioxide gas indicators. The air-stable complexes form 1:1 adducts in the presence of low concentrations of sulfur dioxide gas, with an associated color change from nearly colorless to yellow-orange. The mercaptides are made by mixing stoichiometric amounts of the appropriate copper(I) mercaptide and phosphine in an inert organic solvent.

  11. Sorption of copper by vegetated copper-mine tailings

    NASA Astrophysics Data System (ADS)

    de Coninck, A.; Karam, A.; Jaouich, A.

    2009-04-01

    The lixiviation of copper (Cu) from vegetated mine tailings may present an environmental risk because of the potential adverse effects it may pose to ground and surface water around mines. However, bonding of Cu to mine tailings can limit transfer to surrounding water. The main objective of the present study is to assess Cu sorption by cultivated Cu-mine tailings containing calcite (pH 7.7) as influenced by commercial peat moss-shrimp waste compost (PSC) and chelating solution. Fresh tailing and tailing that had been used in pot experiments were tested and compared. Samples (0.50 g) of tailings were equilibrated with 20 cm3 of 0.01 M CaCl2 solution containing 100 mg Cu dm-3, as CuCl2, for 72 h at room temperature. After equilibration period, the samples were centrifuged and filtered. Concentration of Cu in the equilibrium solution was measured by atomic absorption spectrophotometry. The sorption coefficient (Ks) was used to interpret the sorption data. The sorption experiment was replicated two times. Compost was the most effective organic amendment in enhancing Cu sorption. The Ks values were positively and significantly correlated with organic matter content and Cu associated with the organic fraction of tailing samples. The mineralogy and organic matter content can influence the sorption capacity of Cu-mine tailings. Calcite-containing mine tailings amended with PSC can be used to sorb Cu from chloride solutions.

  12. Copper stable isotopes to trace copper behavior in wetland systems.

    PubMed

    Babcsányi, Izabella; Imfeld, Gwenaël; Granet, Mathieu; Chabaux, François

    2014-05-20

    Wetlands are reactive zones of the landscape that can sequester metals released by industrial and agricultural activities. Copper (Cu) stable isotope ratios (?(65)Cu) have recently been used as tracers of transport and transformation processes in polluted environments. Here, we used Cu stable isotopes to trace the behavior of Cu in a stormwater wetland receiving runoff from a vineyard catchment (Alsace, France). The Cu loads and stable isotope ratios were determined in the dissolved phase, suspended particulate matter (SPM), wetland sediments, and vegetation. The wetland retained >68% of the dissolved Cu and >92% of the SPM-bound Cu, which represented 84.4% of the total Cu in the runoff. The dissolved Cu became depleted in (65)Cu when passing through the wetland (?(65)Cuinlet-outlet from 0.03‰ to 0.77‰), which reflects Cu adsorption to aluminum minerals and organic matter. The ?(65)Cu values varied little in the wetland sediments (0.04 ± 0.10‰), which stored >96% of the total Cu mass within the wetland. During high-flow conditions, the Cu flowing out of the wetland became isotopically lighter, indicating the mobilization of reduced Cu(I) species from the sediments and Cu reduction within the sediments. Our results demonstrate that the Cu stable isotope ratios may help trace Cu behavior in redox-dynamic environments such as wetlands. PMID:24787375

  13. Regulation of Copper Transporter 2 Expression by Copper and Cisplatin in Human Ovarian Carcinoma Cells

    PubMed Central

    Blair, Brian G.; Larson, Christopher A.; Adams, Preston L.; Abada, Paolo B.; Safaei, Roohangiz

    2010-01-01

    Down-regulation of copper transporter 1 (CTR1) reduces uptake and sensitivity, whereas down-regulation of CTR2 enhances both. Cisplatin (DDP) triggers the rapid degradation of CTR1 and thus limits its own accumulation. We sought to determine the effect of DDP and copper on the expression of CTR2. Changes in CTR1 and CTR2 mRNA and protein levels in human ovarian carcinoma 2008 cells and ATOX1(+/+) and ATOX1(?/?) mouse embryo fibroblasts in response to exposure to DDP and copper were measured by quantitative reverse transcriptase-polymerase chain reaction, Western blot analysis, and deconvolution microscopy. DDP triggered rapid degradation of CTR1 in 2008 human ovarian cancer cells. However, it increased the expression of CTR2 mRNA and protein levels. Expression of CTR2 was heavily modulated by changes in intracellular copper concentration; copper depletion produced rapid disappearance of CTR2, whereas excess copper increased the level of CTR2 protein. This increase was associated with an increase in CTR2 mRNA and prolongation of the CTR2 half-life. Consistent with prior observations that short hairpin RNA interference-mediated knockdown of CTR2 enhanced DDP uptake and tumor cell kill, reduction of CTR2 by copper starvation also enhanced DDP uptake and cytotoxicity. Comparison of the ability of copper and DDP to modulate the expression of CTR1 in ATOX1(+/+) and ATOX1(?/?) indicated that ATOX1 participates in the regulation of CTR2 expression. Unlike CTR1, the expression of CTR2 is increased rather than decreased by DDP. Therefore, these two copper transporters have opposite effects on DDP sensitivity. CTR2 expression is regulated by copper availability via the copper-dependent regulator ATOX1. PMID:20194531

  14. 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

  15. Ternary lanthanum sulfide selenides {alpha}-LaS{sub 2-x}Se{sub x} (0

    SciTech Connect

    Bartsch, Christian [Department of Chemistry and Food Chemistry, Technische Universitaet Dresden, D-01062 Dresden (Germany); Doert, Thomas, E-mail: thomas.doert@chemie.tu-dresden.de [Department of Chemistry and Food Chemistry, Technische Universitaet Dresden, D-01062 Dresden (Germany)

    2012-01-15

    Mixed lanthanum sulfide selenides LaS{sub 2-x}Se{sub x} (0selenides. Highlights: Black-Right-Pointing-Pointer Vegard series of mixed lanthanum sulfide selenides LaS{sub 2-x}Se{sub x} (0

  16. Thick film oxidation of copper in an electroplated MEMS process

    NASA Astrophysics Data System (ADS)

    Lazarus, N.; Meyer, C. D.; Bedair, S. S.; Song, X.; Boteler, L. M.; Kierzewski, I. M.

    2013-06-01

    Copper forms a porous oxide, allowing the formation of oxide layers up to tens of microns thick to be created at modest processing temperatures. In this work, the controlled oxidation of copper is employed within an all-metal electroplating process to create electrically insulating, structural posts and beams. This capability could eliminate the additional dielectric deposition and patterning steps that are often needed during the construction of sensors, waveguides, and other microfabricated devices. In this paper, copper oxidation rates for thermal and plasma-assisted growth methods are characterized. Time control of the oxide growth enables larger copper structures to remain conductive while smaller copper posts are fully oxidized. The concept is demonstrated using the controlled oxidation of a copper layer between two nickel layers to fabricate nickel inductors having both copper electrical vias and copper oxide support pillars. Nickel was utilized in this demonstration for its resistance against low temperature oxidation and interdiffusion with copper.

  17. 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.

  18. Active Uptake of Copper and Zinc during Haemodialysis

    PubMed Central

    Blomfield, Jeanette; McPherson, Jean; George, C. R. P.

    1969-01-01

    The uptake of copper and zinc by patients undergoing regular haemodialysis has been assessed by measuring the dialysis fluid for copper and zinc concentration, and the blood entering and leaving the dialysis coil for red cell copper, plasma free copper, and plasma zinc levels during priming of the coil and subsequent haemodialysis, and by in-vitro studies. Red cells avidly removed copper from dialysis fluid when mixed with saline during priming, but did not take up copper during the haemodialysis. At both these stages plasma actively took up both copper and zinc from dialysis fluid, even against a concentration gradient, so that loss of these metals from plasma to dialysis fluid did not occur. In the dialysis systems investigated the sources of the copper in the dialysis fluid were the copper plumbing of the tap-water and the dialysis coil, and the major source of zinc was the zinc oxide of the adhesive plaster around the dialysis coil. PMID:5778936

  19. {[M(NH3)6][Ag4M4Sn3Se13]}? (M=Zn, Mn): Three-dimensional chalcogenide frameworks constructed from quaternary metal selenide clusters with two different transition metals

    NASA Astrophysics Data System (ADS)

    Xiong, Wei-Wei; Miao, Jianwei; Li, Pei-Zhou; Zhao, Yanli; Liu, Bin; Zhang, Qichun

    2014-10-01

    Herein we report solvothermal syntheses of two new three-dimensional chalcogenide frameworks {[M(NH3)6][Ag4M4Sn3Se13]}n (M=Zn (1), Mn (2)), which consist of quaternary metal selenide clusters with two different transition metals. The compounds represent the first Ag-Zn/Mn-Sn-Se based quaternary anionic frameworks. The optical studies show that the band gaps for 1 and 2 are 2.09 eV and 1.71 eV, respectively. Moreover, the photoelectrochemical study indicates that compound 1 displays n-type semiconducting behaviour and is photoactive under visible light illumination (?>400 nm).

  20. 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.

  1. Speciation and leachability of copper in mine tailings from porphyry copper mining: influence of particle size.

    PubMed

    Hansen, Henrik K; Yianatos, Juan B; Ottosen, Lisbeth M

    2005-09-01

    Mine tailing from the El Teniente-Codelco copper mine situated in VI Region of Chile was analysed in order to evaluate the mobility and speciation of copper in the solid material. Mine tailing was sampled after the rougher flotation circuits, and the copper content was measured to 1150 mg kg (-1) dry matter. This tailing was segmented into fractions of different size intervals: 0-38, 38-45, 45-53, 53-75, 75-106, 106-150, 150-212, and >212 microm, respectively. Copper content determination, sequential chemical extraction, and desorption experiments were carried out for each size interval in order to evaluate the speciation of copper. It was found that the particles of smallest size contained 50-60% weak acid leachable copper, whereas only 32% of the copper found in largest particles could be leached in weak acid. Copper oxides and carbonates were the dominating species in the smaller particles, and the larger particles contained considerable amounts of sulphides. PMID:16054920

  2. Abrasive Wear Behaviour of COPPER-SiC and COPPER-SiO2 Composites

    NASA Astrophysics Data System (ADS)

    Umale, Tejas; Singh, Amarjit; Reddy, Y.; Khatitrkar, R. K.; Sapate, S. G.

    The present paper reports abrasive wear behaviour of copper matrix composites reinforced with silicon carbide and silica particles. Copper - SiC (12%) and Copper-SiO2 (9%) composites were prepared by powder metallurgical technique. Metallography, image analysis and hardness studies were carried out on copper composites. The abrasive wear experiments were carried out using pin on disc apparatus. The effect of sliding distance and load was studied on Copper - SiC (12%) and Copper-SiO2 (9%) composites. The abrasive wear volume loss increased with sliding distance in both the composites although the magnitude of increase was different in each case. Copper - SiC (12%) composites exhibited relatively better abrasion resistance as compared to and Copper-SiO2 (9%) composites. The abraded surfaces were observed under scanning electron microscope to study the morphology of abraded surfaces and operating wear mechanism. The analysis of wear debris particles was also carried out to substantiate the findings of the investigation.

  3. Spreading and interlayer formation at the copper-copper oxide\\/polycrystalline alumina interface

    Microsoft Academic Search

    M. D. Baldwin; P. R. Chidambaram; G. R. Edwards

    1994-01-01

    Spreadability and reaction layer growth rates of copper-oxygen alloys on polycrystalline alumina were measured above the melting point of copper to better understand the direct bonding process. Spreading was measured as a function of composition and temperature by monitoring the diameter of molten droplets as a function of time. As the oxygen content of the melt increased from 0 to

  4. 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

  5. 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

  6. 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).

  7. Phototunable Magnetism in Copper Octacyanomolybdate

    PubMed Central

    Ohara, Jun

    2014-01-01

    We introduce copper molybdenum cyanides of general formula Cu2[Mo(CN)8]·nH2O, which can serve as optofunctional magnetic devices. Their ground states generally stay paramagnetic down to temperatures of the K order but exhibit a spontaneous magnetization upon photoirradiation usually below a few tens of K. To interest us still further, such a ferromagnetic stateinduced by blue-laser irradiation is demagnetized step by step through further application of red or near-infrared laser pulses. We solve this intriguing photomagnetism. The ground-state properties are fully revealed by means of a group-theoretical technique. Taking account of experimental observations, we simulate applying pump laser pulses to a likely ground state and successfully reproduce both the magnetization and demagnetization dynamics. We monitor the photorelaxation process through angle-resolved photoemission spectroscopy. Electrons are fully itinerant in any of the photoinduced steady states, forming a striking contrast to the initial equilibrium state of atomic aspect. The fully demagnetized final steady state looks completely different from the initial paramagnetism but bears good analogy to one of the possible ground states available with the Coulomb repulsion on Cu sites suppressed. PMID:24895661

  8. Metal (copper) segregation in magmas

    NASA Astrophysics Data System (ADS)

    Vigneresse, Jean-Louis; Truche, Laurent; Chattaraj, Pratim K.

    2014-11-01

    Before precipitating to form porphyry-type deposits, metals are transported and concentrated into magmas. Ultimately, they can enter crystalline phases or segregate into the volatile phase. In both cases, partition coefficients determine the partitioning according to the ambient physico-chemical conditions. Metal partitioning between the melt and the magmatic volatile phase (MVP) is driven by their solubility. In this study, Cu has been selected as a test for metal segregation. We evaluate qualitatively the metal's behavior with respect to the melt or to the MVP by comparing the difference in chemical potential and polarizability between the fluid phase and dissolved copper compound. Maps of polarizability are drawn after computing the chemical reactivity parameters (electrophilicity, hardness, and polarizability) for various silicate melts; a synthetic fluid phase with water, CO2, S18 compounds and halogens; and Cu-compounds as a test metal. Cu-compounds show a better affinity with the fluid phase, enhanced by the presence of S in its reduced form. It explains how Cu could segregate into the fluid phase at the magmatic stage before being enriched by diffusion or melt/vapor partitioning, leading to late hydrothermal precipitation. The method should therefore be considered as a model for understanding the behavior of other metals and their segregation during the magmatic stage.

  9. Oxidation of molten copper matte

    NASA Astrophysics Data System (ADS)

    Asaki, Z.; Ando, S.; Kondo, Y.

    1988-02-01

    An amount of 80 mg of molten copper matte of a pseudo-ternary Cu2S-FeS-Fe system contained in a slender alumina sample tube was oxidized at 1503 and 1533 K in a mixed O2-Ar gas stream and the oxidation path was followed, comparing the overall rate of oxidation with the gaseous diffusion in the sample tube. The following successive reactions were found to be controlled by gas diffusion. Initially, Fe was oxidized to form FeO. After the melt composition reached a pseudo-ternary Cu2S-FeS-FeO system, FeS was oxidized to form FeO. As the amount of FeO increased, Fe3O4 was also formed and subsequently Cu was produced by the oxidation of Cu2S. In the latter stage, the Cu was oxidized, and the final product under the condition of gas diffusion control was composed of Cu2O, Fe3O4, and CuFeO2. On the other hand, the rate of formation of Fe2O3, CuO, and CuFe2O4 was much slower and they were not formed during the oxidation duration where the overall rate of oxidation was controlled by gas diffusion.

  10. The Copper Balance of Cities

    PubMed Central

    Kral, Ulrich; Lin, Chih-Yi; Kellner, Katharina; Ma, Hwong-wen; Brunner, Paul H

    2014-01-01

    Material management faces a dual challenge: on the one hand satisfying large and increasing demands for goods and on the other hand accommodating wastes and emissions in sinks. Hence, the characterization of material flows and stocks is relevant for both improving resource efficiency and environmental protection. This article focuses on the urban scale, a dimension rarely investigated in past metal flow studies. We compare the copper (Cu) metabolism of two cities in different economic states, namely, Vienna (Europe) and Taipei (Asia). Substance flow analysis is used to calculate urban Cu balances in a comprehensive and transparent form. The main difference between Cu in the two cities appears to be the stock: Vienna seems close to saturation with 180 kilograms per capita (kg/cap) and a growth rate of 2% per year. In contrast, the Taipei stock of 30 kg/cap grows rapidly by 26% per year. Even though most Cu is recycled in both cities, bottom ash from municipal solid waste incineration represents an unused Cu potential accounting for 1% to 5% of annual demand. Nonpoint emissions are predominant; up to 50% of the loadings into the sewer system are from nonpoint sources. The results of this research are instrumental for the design of the Cu metabolism in each city. The outcomes serve as a base for identification and recovery of recyclables as well as for directing nonrecyclables to appropriate sinks, avoiding sensitive environmental pathways. The methodology applied is well suited for city benchmarking if sufficient data are available. PMID:25866460

  11. Heme/copper terminal oxidases

    SciTech Connect

    Ferguson-Miller, S.; Babcock, G.T. [Michigan State Univ., East Lansing, MI (United States)] [Michigan State Univ., East Lansing, MI (United States)

    1996-11-01

    Spatially well-organized electron-transfer reactions in a series of membrane-bound redox proteins form the basis for energy conservation in both photosynthesis and respiration. The membrane-bound nature of the electron-transfer processes is critical, as the free energy made available in exergonic redox chemistry is used to generate transmembrane proton concentration and electrostatic potential gradients. These gradients are subsequently used to drive ATP formation, which provides the immediate energy source for constructive cellular processes. The terminal heme/copper oxidases in respiratory electron-transfer chains illustrate a number of the thermodynamic and structural principles that have driven the development of respiration. This class of enzyme reduces dioxygen to water, thus clearing the respiratory system of low-energy electrons so that sustained electron transfer and free-energy transduction can occur. By using dioxygen as the oxidizing substrate, free-energy production per electron through the chain is substantial, owing to the high reduction potential of O{sub 2} (0.815 V at pH 7). 122 refs.

  12. Utilization of Copper Alloys for Marine Applications

    NASA Astrophysics Data System (ADS)

    Drach, Andrew

    Utilization of copper alloy components in systems deployed in marine environment presents potential improvements by reducing maintenance costs, prolonging service life, and increasing reliability. However, integration of these materials faces technological challenges, which are discussed and addressed in this work, including characterization of material performance in seawater environment, hydrodynamics of copper alloy components, and design procedures for systems with copper alloys. To characterize the hydrodynamic behavior of copper alloy nets, mesh geometry of the major types of copper nets currently used in the marine aquaculture are analyzed and formulae for the solidity and strand length are proposed. Experimental studies of drag forces on copper alloy net panels are described. Based on these studies, empirical values for normal drag coefficients are proposed for various types of copper netting. These findings are compared to the previously published data on polymer nets. It is shown that copper nets exhibit significantly lower resistance to normal currents, which corresponds to lower values of normal drag coefficient. The seawater performance (corrosion and biofouling) of copper alloys is studied through the field trials of tensioned and untensioned specimens in a one-year deployment in the North Atlantic Ocean. The corrosion behavior is characterized by weight loss, optical microscopy, and SEM/EDX analyses. The biofouling performance is quantified in terms of the biomass accumulation. To estimate the effects of stray electrical currents on the seawater corrosion measurements, a low cost three-axis stray electric current monitoring device is designed and tested both in the lab and in the 30-day field deployment. The system consists of a remotely operated PC with a set of pseudo-electrodes and a digital compass. The collected data is processed to determine magnitudes of AC and DC components of electric field and dominant AC frequencies. Mechanical behavior of copper alloys is investigated through a series of uniaxial tension tests on virgin and weathered (after one-year deployment in the ocean) specimens. The changes in mechanical properties are quantified in terms of differences in Young's modulus, Poisson's ratio, ultimate strength, and ultimate strain. The obtained stress-strain data is used for numerical modeling of the mechanical behavior of chain-link nets. The simulations are compared with the experimental data on stiffness and strength of the nets. The available information on seawater performance of copper alloys (corrosion, biofouling, mechanics) and copper alloy nets (hydrodynamics) is used to develop engineering procedures for marine aquaculture fish cage systems with copper alloy netting. The design, analysis, and fabrication procedures are illustrated on a commercial size gravity-type offshore fish cage deployed in the Pacific Ocean near Isla Italia (Patagonia, Chile). The funding for this work was provided by the International Copper Association. This work was also supported through two UNH Fellowships: CEPS UNH Graduate Fellowship to Outstanding PhD Program Applicants and Dissertation Year Fellowship.

  13. One-step brazing process to join CFC composites to copper and copper alloy

    NASA Astrophysics Data System (ADS)

    Salvo, Milena; Casalegno, Valentina; Rizzo, Stefano; Smeacetto, Federico; Ferraris, Monica; Merola, Mario

    2008-02-01

    The aim of this work is to develop a new single-step brazing technique to join carbon fibre reinforced carbon composite (CFC) to pure copper (Cu) and copper alloy (CuCrZr) for nuclear fusion applications. In order to increase the wettability of CFC by a copper-based brazing alloy containing no active metal, the composite surface was modified by direct reaction with chromium, which forms a carbide layer and allows a large reduction of the contact angle. After the CFC surface modification, the commercial Gemco ® alloy (Cu/Ge) was successfully used to braze CFC to pure copper and pure copper to CuCrZr by the same heat treatment. The shear strength of the CFC/Cu joints measured by single lap shear tests at room temperature was (34 ± 4) MPa, comparable to the values obtained by other joining processes and higher than the intrinsic CFC shear strength.

  14. Extracting copper from copper oxide ore by a zwitterionic reagent and dissolution kinetics

    NASA Astrophysics Data System (ADS)

    Deng, Jiu-shuai; Wen, Shu-ming; Deng, Jian-ying; Wu, Dan-dan

    2015-03-01

    Sulfamic acid (SA), which possesses a zwitterionic structure, was applied as a leaching reagent for the first time for extracting copper from copper oxide ore. The effects of reaction time, temperature, particle size, reagent concentration, and stirring speed on this leaching were studied. The dissolution kinetics of malachite was illustrated with a three-dimensional diffusion model. A novel leaching effect of SA on malachite was eventually demonstrated. The leaching rate increased with decreasing particle size and increasing concentration, reaction temperature and stirring speed. The activation energy for SA leaching malachite was 33.23 kJ/mol. Furthermore, the effectiveness of SA as a new reagent for extracting copper from copper oxide ore was confirmed by experiment. This approach may provide a solution suitable for subsequent electrowinning. In addition, results reported herein may provide basic data that enable the leaching of other carbonate minerals of copper, zinc, cobalt and so on in an SA system.

  15. 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.

  16. 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.

  17. Diorganotin(IV) 2-pyridyl selenolates: synthesis, structures and their utility as molecular precursors for the preparation of tin selenide nanocrystals and thin films.

    PubMed

    Sharma, Rakesh K; Kedarnath, G; Wadawale, Amey; Betty, C A; Vishwanadh, B; Jain, Vimal K

    2012-10-21

    Reactions of R(2)SnCl(2) (R = Me, Et, (t)Bu) with NaSeC(5)H(3)(R'-3)N (R' = H or Me) gave complexes of the composition [R(2)Sn{2-SeC(5)H(3)(R'-3)N)}(2)], which on treatment with R(2)SnCl(2) afforded chloro complexes, [R(2)Sn{2-SeC(5)H(3)(R'-3)N}Cl]. These complexes were characterized by elemental analyses and UV-vis and NMR ((1)H, (13)C, (77)Se and (119)Sn) spectroscopy. The crystal structures of [R(2)Sn(SeC(5)H(4)N)(2)] (R = Me or (t)Bu) and [Me(2)Sn{2-SeC(5)H(3)(Me-3)N}Cl] were determined by single crystal X-ray diffraction. The tin atom in the former two structures acquires a skew trapezoidal configuration, whereas in the latter it adopts a distorted trigonal bipyramidal geometry. Thermolysis of [R(2)Sn(2-SeC(5)H(4)N)(2)] (R = Me, Et or (t)Bu) and [Et(2)Sn{2-SeC(5)H(3)(Me-3)N}(2)] in oleylamine (OA) afforded tin selenide nanostructures. Thin films of SnSe were deposited on glass and silicon substrates by the AACVD of [(t)Bu(2)Sn(2-SeC(5)H(4)N)(2)]. The nanostructures and thin films were characterized by XRD, EDX, AFM, SEM, TEM and SAED techniques. The photovoltaic properties of the thin films have been evaluated. PMID:22918450

  18. Synthesis and characterization of quaternary selenides Sn 2Pb 5Bi 4Se 13 and Sn 8.65Pb 0.35Bi 4Se 15

    NASA Astrophysics Data System (ADS)

    Chen, Kuei-Bo; Lee, Chi-Shen

    2009-09-01

    Quaternary selenides Sn 2Pb 5Bi 4Se 13 and Sn 8.65Pb 0.35Bi 4Se 15 were synthesized from the elements in sealed silica tubes; their crystal structures were determined by single-crystal and powder X-ray diffraction. Both compounds crystallize in monoclinic space group C2/ m (No.12), with lattice parameters of Sn 2Pb 5Bi 4Se 13: a = 14.001(6) Å, b = 4.234(2) Å, c = 23.471(8) Å, V = 1376.2(1) Å 3, R1/ wR2 = 0.0584/0.1477, and GOF = 1.023; Sn 8.65Pb 0.35Bi 4Se 15: a = 13.872(3) Å, b = 4.2021(8) (4) Å, c = 26.855(5) Å, V = 1557.1(5) Å 3, R1/ wR2 = 0.0506/0.1227, and GOF = 1.425. These compounds exhibit tropochemical cell-twinning of NaCl-type structures with lillianite homologous series L(4, 5) and L(4, 7) for Sn 2Pb 5Bi 4Se 13 and Sn 8.65Pb 0.35Bi 4Se 15, respectively. Measurements of electrical conductivity indicate that these materials are semiconductors with narrow band gaps; Sn 2Pb 5Bi 4Se 13 is n-type, whereas Sn 8.65Pb 0.35Bi 4Se 15 is a p-type semiconductor with Seebeck coefficients -80(5) and 178(7) ?V/K at 300 K, respectively.

  19. 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

  20. Structural, magnetic, and electronic properties of iron selenide Fe6-7Se8 nanoparticles obtained by thermal decomposition in high-temperature organic solvents

    NASA Astrophysics Data System (ADS)

    Lyubutin, I. S.; Lin, Chun-Rong; Funtov, K. O.; Dmitrieva, T. V.; Starchikov, S. S.; Siao, Yu-Jhan; Chen, Mei-Li

    2014-07-01

    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 Fe3+ ions and stimulate the magnetic transition with the rotation of the Fe3+ 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.

  1. 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.

  2. Runoff rates, chemical speciation and bioavailability of copper released from naturally patinated copper.

    PubMed

    Karlén, C; Wallinder, I Odnevall; Heijerick, D; Leygraf, C

    2002-01-01

    The release of copper, induced by atmospheric corrosion, from naturally patinated copper of varying age (0 and 30 years) has been investigated together with its potential ecotoxic effect. Results were generated in an interdisciplinary research effort in which corrosion science and ecotoxicology aspects were combined. The aim of the investigation was to elucidate the situation when copper-containing rainwater leaves a roof in terms of runoff rate, chemical speciation, bioavailability and ecotoxicity effects. Data have been collected during a three-year field exposure conducted in the urban environment of Stockholm, Sweden. The potential environmental effects have been evaluated using a combination of a copper specific biosensor test with the bacterium Alcaligenes eutrophus and the conventional 72-h growth inhibition test with the green alga Raphidocelis subcapitata. The results show annual runoff rates between 1.0 and 1.5 g/m2 year for naturally patinated copper of varying age. The runoff rate increased slightly with patina age, which mainly is attributed to the enhanced first flush effect observed on thicker patina layers. The total copper concentration in investigated runoff samplings ranged from 0.9 to 9.7 mg/l. Both computer modeling and experimental studies revealed that the majority (60-100%) of released copper was present as the free hydrated cupric ion, Cu(H2O)6(2+), the most bioavailable copper species. However, other copper species in the runoff water, such as, e.g. Cu(OH)+ and Cu2(OH)2(2+), were also bioavailable. The copper-containing runoff water, sampled directly after release from the roof, caused significant reduction in growth rate of the green alga. It should be emphasized that the results describe the runoff situation immediately after release from the copper roof and not the real environmental ecotoxicity. Therefore the data should only be used as an initial assessment of the potential environmental effect of copper runoff from building applications. Future risk assessments should also consider dilution effects of copper, changes in its chemical speciation and bioavailability during environmental entry, and type and sensitivity of the receiving ecosystem. PMID:12442792

  3. Serum copper, ceruloplasmin and 24-h urine copper evaluations in celiac patients.

    PubMed

    Ince, Ali Tüzün; Kayadibi, Hüseyin; Soylu, Aliye; Ovunç, Oya; Gültepe, Mustafa; Toros, Ahmet Burak; Ya?ar, Bülent; Kendir, Tulin; Abut, Evren

    2008-06-01

    The aim of the study is to evaluate the serum copper, ceruloplasmin and 24-h urine copper levels in celiac patients. Serum copper, ceruloplasmin and 24-h urine measurements were evaluated in patients with celiac (n = 32), Crohn's (n = 25), Wilson's (n = 11) and in a healthy group (n = 35). Serum and 24-h urine zinc levels, AST, ALT, BUN, creatinine, iron, hemoglobin, hematocrit, lymphocyte, sedimentation and CRP levels were also measured. Results were evaluated statistically and significance was accepted as meaningful if P < 0.05. In celiacs, levels of urine copper were high (52 +/- 29 microg/day, P < 0.000) but serum copper was the same as in controls (105 +/- 16 microg/dl, P < 0.158). High urinary copper of celiacs were coming out in women (56 +/- 30 microg/day) and in man (33 +/- 17 microg/day, P < 0.115). Most celiacs were female (P < 0.001). Serum copper and ceruloplasmin levels in all groups were higher in women than in men and this was meaningful for serum copper in the control group (P < 0.045) and for ceruloplasmin in Crohn's (P < 0.055) and control groups (P < 0.031). Serum (70 +/- 14 microg/dl, P < 0.000) and urine zinc levels (25 +/- 15 microg/dl, P < 0.039) of celiacs were low. Ceruloplasmin levels were higher in celiacs (337 +/- 64 U/1) and Crohn's patients (366 +/- 47 U/l, P < 0.000). Correlations observed in the groups of celiac (P < 0.029) and Crohn's (P < 0.024), celiac and Wilson's (P < 0.001) and Crohn's and Wilson's (P < 0.001) between the ceruloplasmin and 24-h urine copper parameters. AST and ALT levels were higher in celiac and Wilson's patients than in Crohn's patients and controls. Mean CRP levels were significantly higher in Crohn's than others. Lymphocyte counts were meaningfully higher in celiacs. Statistically, while mean iron, hemoglobulin and hematocrit levels of celiac and Crohn groups were meaningfully lower than the normal and Wilson's group, it was similar in Wilson's and the control group. Serum copper (85 +/- 26 microg/dl, P < 0.158) and ceruloplasmin (219 +/- 83 U/l, P < 0.001) levels were low and 24-h urine copper levels were high (415 +/- 346 microg/day) in Wilson's group. Increased urinary loss may be another cause of copper deficiency in female celiacs besides malabsorption and this topic needs more investigation. Increased urinary copper levels in celiac women should not always be regarded as a diagnosis of Wilson's disease. PMID:17934856

  4. Acute toxicity of aqueous and substrate-bound copper to the midge, Chironomus decorus

    Microsoft Academic Search

    Prapimpan Kosalwat; Allen W. Knight

    1987-01-01

    Fourth instar larvae of the midge,Chironomus decorus, were exposed to copper in water and copper in food and substrate (bound forms). Copper present in aqueous forms was more toxic than when it was present in bound forms. The relationship between copper in water and copper in midges could be described by an exponential equation while the relationship between copper in

  5. Characterization of copper-resistant rhizosphere bacteria from Avena sativa and Plantago lanceolata for copper bioreduction and biosorption.

    PubMed

    Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Camargo, Flávio A O

    2012-04-01

    Copper is a toxic heavy metal widely used to microbial control especially in agriculture. Consequently, high concentrations of copper residues remain in soils selecting copper-resistant organisms. In vineyards, copper is routinely used for fungi control. This work was undertaken to study copper resistance by rhizosphere microorganisms from two plants (Avena sativa L. and Plantago lanceolata L.) common in vineyard soils. Eleven rhizosphere microorganisms were isolated, and four displayed high resistance to copper. The isolates were identified by 16S rRNA gene sequence analysis as Pseudomonas putida (A1), Stenotrophomonas maltophilia (A2) and Acinetobacter sp. (A6), isolated from Avena sativa rhizosphere, and Acinetobacter sp. (T5), isolated from Plantago lanceolata rhizosphere. The isolates displayed high copper resistance in the temperature range from 25°C to 35°C and pH in the range from 5.0 to 9.0. Pseudomonas putida A1 resisted as much as 1,000 mg L(-1) of copper. The isolates showed similar behavior on copper removal from liquid medium, with a bioremoval rate of 30% at 500 mg L(-1) after 24 h of growth. Speciation of copper revealed high copper biotransformation, reducing Cu(II) to Cu(I), capacity. Results indicate that our isolates are potential agents for copper bioremoval and bacterial stimulation of copper biosorption by Avena sativa and Plantago lanceolata. PMID:22002857

  6. 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

  7. Nanotube Boiler 1 Abstract--Controlled copper evaporation at attogram

    E-print Network

    Paris-Sud XI, Université de

    Nanotube Boiler 1 Abstract-- Controlled copper evaporation at attogram level from individual carbon nanotube (CNT) vessels, which we call nanotube boilers, is investigated experimentally for evaporation is by positively ionizing the encapsulated copper, therefore, an electrostatic field can be used

  8. 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

  9. 49 CFR 192.377 - Service lines: Copper.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.377 Service lines: Copper. Each copper service line installed...

  10. 49 CFR 192.377 - Service lines: Copper.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.377 Service lines: Copper. Each copper service line installed...

  11. 49 CFR 192.377 - Service lines: Copper.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.377 Service lines: Copper. Each copper service line installed...

  12. 49 CFR 192.377 - Service lines: Copper.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.377 Service lines: Copper. Each copper service line installed...

  13. Metals in Metal Salts: A Copper Mirror Demonstration

    ERIC Educational Resources Information Center

    Pike, Robert D.

    2010-01-01

    A simple lecture demonstration is described to show the latent presence of metal atoms in a metal salt. Copper(II) formate tetrahydrate is heated in a round-bottom flask forming a high-quality copper mirror.

  14. Protective coating for copper in aluminum heat exchangers

    NASA Technical Reports Server (NTRS)

    Avazian, R.

    1978-01-01

    Application of ultrathin layer of molybdenum disulfied coating to copper tubing permits utilization of tubing in cast-aluminum heat exchangers. Coating prevents formation of copper/aluminum eutectic, but does not impede heat transfer.

  15. 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

  16. Behaviour of non-standard composition copper bearing anodes from the copper refining process.

    PubMed

    Markovi?, R; Friedrich, B; Staji?-Trosi?, J; Jordovi?, B; Jugovi?, B; Gvozdenovi?, M; Stevanovi?, J

    2010-10-15

    This paper addresses on investigation the possibility of electrolytic treatment the sulphur acidic waste solution, obtained in the conventional electrolytic copper refining process. Beside the high copper concentration, the high concentration of other metals, in this case nickel, is the main characteristic of these waste solutions. Due to this fact, the copper bearing anodes with non-standard nickel, lead, tin and antimony content were specially prepared for the refining process. Nickel content of all anodes was approximately 7.5 mass%, and the content of lead, tin and antimony was varied. The preliminary results, obtained using the standard electrochemical techniques, have indicated that the copper bearing anodes could be used under the same conditions as well as in the conventional copper refining process. The measurements in constant galvanostatic pulse have pointed out that the all chemical elements from copper bearing anodes were dissolved and only copper was deposited onto the cathode. It was also pointed out that Ni concentration in the base working electrolyte (sulphur acidic waste solution), after 72 h of process, increased to 102 mass% at T(1)=63+/-2 degrees C and up to 122 mass% at T(1)=73+/-2 degrees C, while arsenic concentration decreased to a minimum value. PMID:20667423

  17. Electrochemical entry of hydrogen into copper

    SciTech Connect

    Platonov, B.M.; Polukarov, Yu. M.; Urin, O.V.

    1984-08-01

    This article studies the effect of hydrogen entry into copper foils in 1 N H/sub 2/SO/sub 4/ and 1 N Na/sub 2/SO/sub 4/ with and without the addition of 0.1 g/liter of thiourea. The foils were examined for the extent of hydrogen saturation and changes in length, resistivity and crystal lattice constant. Results show that a copper substrate cannot be used as an inert material in studying hydrogen sorption or measuring internal stresses in metal deposits where the plating is accompanied by hydrogen ion discharge. An example shown is hydrogen entry into copper via a 5-micrometer nickel film from solutions with and without a hydrogen stimulator. Hydrogen attack in such a system caused cathode elongation and hydrogen adsorption.

  18. Evaluating wild grapevine tolerance to copper toxicity.

    PubMed

    Cambrollé, J; García, J L; Figueroa, M E; Cantos, M

    2015-02-01

    We evaluate copper tolerance and accumulation in Vitis vinifera ssp. sylvestris in populations from a copper contaminated site and an uncontaminated site, and in the grapevine rootstock "41B", investigating the effects of copper (0-23 mM) on growth, photosynthetic performance and mineral nutrient content. The highest Cu treatment induced nutrient imbalances and inhibited photosynthetic function, causing a drastic reduction in growth in the three study plants. Effective concentration was higher than 23 mM Cu in the wild grapevines and around 9 mM in the "41B" plants. The wild grapevine accessions studied controlled root Cu concentration more efficiently than is the case with the "41B" rootstock and must be considered Cu-tolerant. Wild grapevines from the Cu-contaminated site present certain physiological characteristics that make them relatively more suitable for exploitation in the genetic improvement of vines against conditions of excess Cu, compared to wild grapevine populations from uncontaminated sites. PMID:25025740

  19. Cascade collapse in copper and nickel

    SciTech Connect

    Vetrano, J.S.; Robertson, I.M.; Averback, R.S. (Illinois Univ., Urbana, IL (USA). Dept. of Materials Science and Engineering); Kirk, M.A. (Argonne National Lab., IL (USA))

    1990-04-01

    In-situ TEM studies of the development of the damage structure produced by heavy ion irradiations have been performed in copper and nickel to investigate the possibility that melting occurs in local regions within displacement cascades. These experiments reveal that as the ion dose increases additional loops form from isolated displacement cascades, but more surprisingly some fo the pre-existing loops are annihilated, change position, size and/or Burgers vector. It was also found that the probability for loop formation and the defect image size are greater in copper than in nickel even at temperatures well below stage 3. It will be demonstrated that these observations provide supporting evidence, albeit indirect, that local melting occurs within the cascade core. These results will be compared to the molecular dynamic computer simulations of the damage created by low energy self-ions in copper and nickel. 15 refs., 4 figs.

  20. Preliminary Model of Porphyry Copper Deposits

    USGS Publications Warehouse

    Berger, Byron R.; Ayuso, Robert A.; Wynn, Jeffrey C.; Seal, Robert R., II

    2008-01-01

    The U.S. Geological Survey (USGS) Mineral Resources Program develops mineral-deposit models for application in USGS mineral-resource assessments and other mineral resource-related activities within the USGS as well as for nongovernmental applications. Periodic updates of models are published in order to incorporate new concepts and findings on the occurrence, nature, and origin of specific mineral deposit types. This update is a preliminary model of porphyry copper deposits that begins an update process of porphyry copper models published in USGS Bulletin 1693 in 1986. This update includes a greater variety of deposit attributes than were included in the 1986 model as well as more information about each attribute. It also includes an expanded discussion of geophysical and remote sensing attributes and tools useful in resource evaluations, a summary of current theoretical concepts of porphyry copper deposit genesis, and a summary of the environmental attributes of unmined and mined deposits.