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1

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...Chemical Substances § 721.10391 Copper gallium indium selenide. (a) Chemical...The chemical substance identified as copper gallium indium selenide (PMN...

2013-07-01

2

Dufour effect in superionic copper selenide  

Microsoft Academic Search

The Dufour effect has been observed in the superionic conductor copper selenide, Cu2?x\\u000a Se. This effect is the opposite of the Soret thermal diffusion effect which was previously only observed in gaseous and liquid\\u000a systems.

M. A. Korzhuev; A. A. Baèkov

1998-01-01

3

Copper Selenide Nanocrystals for Photothermal Therapy  

PubMed Central

Ligand-stabilized copper selenide (Cu2?xSe) 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 × 107 cm?1 M?1 at 980 nm. When excited with 800 nm light, the Cu2?xSe 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 Cu2?xSe nanocrystals in the presence of human colorectal cancer cell (HCT-116) led to cell destruction after 5 minutes of laser irradiation at 33 W/cm2, demonstrating the viabilitiy of Cu2?xSe nanocrystals for photothermal therapy applications.

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

2011-01-01

4

A study of the oxidative dissolution of synthetic copper-silver selenide minerals using the Intermittent galvanostatic polarisation (IGP) technique  

Microsoft Academic Search

Intermittent galvanostatic polarisation, combined with solid state analytical techniques and atomic absorption analysis, has been employed to investigate the electrochemical dissolution of synthetic silver selenide (naumannite) and copper-silver selenide (eucairite) in dilute nitric acid and perchloric acid media. At potentials above 0.75 V vs. SCE, silver selenide is oxidised directly to elemental selenium via the reaction: Ag2Se(c) = 2Ag+(aq) +

R. Luo; N. M. Rice; N. Taylor; R. Gee

1997-01-01

5

Novel complex-assisted photochemical route to the phase control of nanocrystalline copper selenide  

Microsoft Academic Search

Recently, extensive attention has been paid to the preparation and characterization of copper selenide nanoparticles, owing to their composition’s complexity and wide application in solar cells, as an optical filter and as a superionic material [1]. Various methods have been applied to prepare these important nanocrystals, such as solvothermal method [2, 3], ? -irradiation route [4], microwave-assisted heating method [5],

Y. L. Yan; X. F. Qian; J. Yin; Z. K. Zhu

2003-01-01

6

Characterization of copper selenide thin films deposited by chemical bath deposition technique  

NASA Astrophysics Data System (ADS)

A low-cost chemical bath deposition (CBD) technique has been used for the preparation of Cu 2- xSe thin films onto glass substrates and deposited films were characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and UV-vis spectrophotometry. Good quality thin films of smooth surface of copper selenide thin films were deposited using sodium selenosulfate as a source of selenide ions. The structural and optical behaviour of the films are discussed in the light of the observed data.

Al-Mamun; Islam, A. B. M. O.

2004-11-01

7

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

PubMed

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

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

2013-03-12

8

Surface-initiated atom transfer radical polymerization-induced transformation of selenium nanowires into copper selenide@polystyrene core-shell nanowires.  

PubMed

This Article reports the first preparation of cuprous and cupric selenide nanowires coated with a ?5 nm thick sheath of polystyrene (copper selenide@polystyrene). These hybrid nanostructures are prepared by the transformation of selenium nanowires in a one-pot reaction, which is performed under ambient conditions. The composition, purity, and crystallinity of the copper selenide@polystyrene products were assessed by scanning transmission electron microscopy, electron energy-loss spectroscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy techniques. We determined that the single crystalline selenium nanowires are converted into polycrystalline copper selenide@polystyrene nanowires containing both cuprous selenide and cupric selenide. The product is purified through the selective removal of residual, non-transformed selenium nanowires by performing thermal evaporation below the decomposition temperature of these copper selenides. Powder X-ray diffraction of the purified copper selenide nanowires@polystyrene identified the presence of hexagonal, cubic, and orthorhombic phases of copper selenide. These purified cuprous and cupric selenide@polystyrene nanowires have an indirect bandgap of 1.44 eV, as determined by UV-vis absorption spectroscopy. This new synthesis of polymer-encapsulated nanoscale materials may provide a method for preparing other complex hybrid nanostructures. PMID:24041404

Wang, Michael C P; Gates, Byron D

2013-09-17

9

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

SciTech Connect

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.

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

10

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

11

Copper Selenide Nanosnakes: Bovine Serum Albumin-Assisted Room Temperature Controllable Synthesis and Characterization  

PubMed Central

Herein we firstly reported a simple, environment-friendly, controllable synthetic method of CuSe nanosnakes at room temperature using copper salts and sodium selenosulfate as the reactants, and bovine serum albumin (BSA) as foaming agent. As the amounts of selenide ions (Se2?) released from Na2SeSO3 in the solution increased, the cubic and snake-like CuSe nanostructures were formed gradually, the cubic nanostructures were captured by the CuSe nanosnakes, the CuSe nanosnakes grew wider and longer as the reaction time increased. Finally, the cubic CuSe nanostructures were completely replaced by BSA–CuSe nanosnakes. The prepared BSA–CuSe nanosnakes exhibited enhanced biocompatibility than the CuSe nanocrystals, which highly suggest that as-prepared BSA–CuSe nanosnakes have great potentials in applications such as biomedical engineering.

2010-01-01

12

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

Microsoft Academic Search

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

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

2011-01-01

13

Influence of growth and photocatalytic properties of copper selenide (CuSe) nanoparticles using reflux condensation method  

NASA Astrophysics Data System (ADS)

Influence of reaction conditions on the synthesis of copper selenide (CuSe) nanoparticles and their photo degradation activity is studied. Nearly monodispersed uniform size (23–44 nm) nanoparticles are synthesized by varying the reaction conditions using reflux condensation method. The obtained nanoparticles are characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and UV–visible absorption spectroscopy. The X-ray diffraction analysis of the sample shows the formation of nanoparticles with hexagonal CuSe structure. The result indicates that on increasing the reaction time from 4 to 12 h, the particle size decreases from 44 to 23 nm, but an increase in the reaction temperature increases the particle size. The calculated band gap Eg is ranging from 2.34 to 3.05 eV which is blue shifted from the bulk CuSe (2.2 eV). The photocatalytic degradation efficiency of the CuSe nanoparticles on two organic dyes Methylene blue (MB) and Rhodamine-B (RhB) in aqueous solution under UV region is calculated as 76 and 87% respectively.

Sonia, S.; Kumar, P. Suresh; Mangalaraj, D.; Ponpandian, N.; Viswanathan, C.

2013-10-01

14

Bath Parameter Dependence of Chemically-Deposited Copper Selenide Thin Film  

NASA Astrophysics Data System (ADS)

In this article, a low cost chemical bath deposition (CBD) technique has been used for the preparation of Cu2-xSe thin films on to glass substrate. Different thin films (0.2-0.6 ?m) were prepared by adjusting the bath parameter like concentration of ammonia, deposition time, temperature of the solution, and the ratios of the mixing composition between copper and selenium in the reaction bath. From these studies, it reveals that at low concentration of ammonia or TEA, the terminal thicknesses of the films are less, which gradually increases with the increase of concentrations and then drop down at still higher concentrations. It has been found that complexing the Cu2+ ions with TEA first, and then addition of ammonia yields better results than the reverse process. The film thickness increases with the decrease of value x of Cu2-xSe.

Al-Mamun; Islam, A. B. M. O.

15

Synthesis and structure of an "iron-doped" copper selenide cluster molecule: [Cu30Fe2Se6(SePh)24(dppm)4].  

PubMed

CuCl and bis(diphenylphosphanyl)methane (dppm) react in the presence of small amounts of FeCl(3) with PhSeSiMe(3) and Se(SiMe(3))(2) to yield [Cu(30)Fe(2)Se(6)(SePh)(24)(dppm)(4)]. The crystal structure of the compound was determined by single-crystal X-ray analysis to give a mixed copper selenide/selenolate cluster molecule of a new structural type incorporating two central iron atoms. The formal oxidation state of the iron atoms was determined by Mössbauer spectroscopy to be +3, in agreement with quantum chemical calculations and modeling of the magnetic data. In addition, Mössbauer studies show no magnetic hyperfine structure in zero field, and the magnetically perturbed spectrum displays a pattern typical for a diamagnetic species in a transverse field, suggesting a singlet ground state. However, the inclusion of the iron atoms has a distinct influence on the optical properties of the compound compared to similar clusters containing only copper and selenium atoms. PMID:19691303

Eichhöfer, Andreas; Olkowska-Oetzel, Jolanta; Fenske, Dieter; Fink, Karin; Mereacre, Valeriu; Powell, Annie K; Buth, Gernot

2009-09-21

16

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)

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.

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

2008-12-01

17

catena-Poly[[[aqua-copper(II)]bis-[?-bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide  

PubMed Central

The title compound, {[Cu(C10H14N4Se)2(H2O)](BF4)2·2C18H15PO·H2O}n, has a polymeric structure where each CuII ion adopts a square-pyramidal coordination constituted by four N atoms of pyrazole moieties in the equatorial plane and an axial O atom of a water mol­ecule. A pair of bis­(3,5-dimethyl-1H-pyrazol-4-yl) selenide ligands bridges the CuII centres into a chain extending along the c axis. The water mol­ecules, anions and triphenyl­phosphine oxide mol­ecules are involved in inter­molecular hydrogen bonding, which links the chains into a three-dimensional network.

Seredyuk, Maksym; Znovjyak, Kateryna O.; Moroz, Yurii S.; Pavlenko, Vadim A.; Fritsky, Igor O.

2010-01-01

18

Neutralization by metal ions of the toxicity of sodium selenide.  

PubMed

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

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

2013-01-14

19

Selenide retention by mackinawite.  

PubMed

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

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

2012-09-04

20

Molecular Structure of Hydrogen Selenide  

NSDL National Science Digital Library

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.

2003-06-04

21

[Aqua-bis-(nitrato-?O)copper(II)]-?-{bis-[5-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl]selenide}-[diaqua-(nitrato-?O)copper(II)] nitrate monohydrate  

PubMed Central

In the title binuclear complex, [Cu2(NO3)3(C18H16N6Se)(H2O)3]NO3·H2O, the CuII ions are penta­coordinated in a tetra­gonal–pyramidal geometry. In both cases, the equatorial planes are formed by a chelating pyrazole-pyridine group, a water mol­ecule and a nitrate O atom, whereas the apical positions are occupied by a water mol­ecule for one CuII ion and a nitrate O atom for the other. The organic selenide ligand adopts a trans configuration with respect to the C–Se–C plane. Numerous inter­molecular O—H?O and N—H?O hydrogen bonds between the coordinating and lattice water mol­ecules, nitrate anions and pyrazole groups are observed. ?–? stacking inter­actions between the pyridine rings [averaged centroid–centroid distance = 3.652?(5)?Å] are also present. The lattice water molecule is equally disordered over two sets of sites.

Seredyuk, Maksym; Pavlenko, Vadim A.; Gumienna-Kontecka, Elzbieta; Iskenderov, Turganbay S.

2012-01-01

22

[Di-aqua-sesqui(nitrato-?O)hemi(perchlorato-?O)copper(II)]-?-{bis-[5-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl] selenide}-[tri-aqua-(perchlorato-?O)copper(II)] nitrate monohydrate  

PubMed Central

In the binuclear title complex, [Cu2(ClO4)1.5(NO3)1.5(C18H16N6Se)(H2O)5]NO3·H2O, both CuII ions are hexa­coordinated by O and N atoms, thus forming axially elongated CuO4N2 octa­hedra. The equatorial plane of each octa­hedron is formed by one chelating pyrazole–pyridine fragment of the organic ligand and two water mol­ecules. The axial positions in one octa­hedron are occupied by a water mol­ecule and a monodentately coordinated perchlorate anion, while those in the other are occupied by a nitrate anion and a disordered perchlorate/nitrate anion with equal site occupancy. The pyrazole–pyridine units of the organic selenide are trans-oriented to each other with a C—Se—C angle of 96.01?(14)°. In the crystal, uncoordinated nitrate anions and the coordinating water mol­ecules are involved in O—H?O and N—H?O hydrogen bonds, forming a bridge between the pyrazole group and the coordinating water mol­ecules. Further O—H?O hydrogen bonds between the complex mol­ecules and a ?–? stacking inter­action with a centroid–centroid distance of 3.834?(4)?Å are also observed.

Seredyuk, Maksym; Pavlenko, Vadim A.; Znovjyak, Kateryna O.; Gumienna-Kontecka, Elzbieta; Iskenderov, Turganbay S.

2013-01-01

23

Advanced selenide thermoelectric development program. Final report  

SciTech Connect

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

Seetoo, W.R.

1981-07-20

24

Copper  

MedlinePLUS

... form. Copper is often added to vitamin and mineral supplements. But most people are able to get ... arthritis. Today, many multivitamins and other herbal and mineral supplements include copper. What is the evidence? Copper ...

25

Copper.  

PubMed

Copper is an essential trace element, which is an important catalyst for heme synthesis and iron absorption. Following zinc and iron, copper is the third most abundant trace element in the body. Copper is a noble metal, like silver and gold. Useful industrial properties include high thermal and electrical conductivity, low corrosion, alloying ability, and malleability. Most of the metallic copper appears in electrical applications. Copper is a constituent of intrauterine contraceptive devices and the release of copper is necessary for their contraceptive effects. The average daily intake of copper in the US is about 1 mg Cu with the primary source being the diet. The bioavailability of copper from the diet is about 65-70% depending on a variety of factors including chemical form, interaction with other metals, and dietary components. The biological half-life of copper from the diet is 13-33 days with bilary excretion being the major route of elimination. Copper sulfate is a gastric irritant that produces erosion of the lining of the gastrointestinal tract. Chronic copper toxicity is rare and primarily affects the liver. Wilson's disease and Indian childhood cirrhosis are examples of severe chronic liver disease that results from the genetic predisposition to the hepatic accumulation of copper. The serum copper concentration ranges up to approximately 1.5 mg/L in healthy persons. Gastrointestinal symptoms occur at whole blood concentrations near 3 mg Cu/L. Chelating agents (CaNa2EDTA, BAL) are recommended in severe poisoning, but there are little pharmacokinetic data to evaluate the effectiveness of these agents. PMID:10382557

Barceloux, D G

1999-01-01

26

Hollow cadmium selenide semiconductor tetrapods  

NASA Astrophysics Data System (ADS)

Hollow cadmium selenide (CdSe) tetrapods were synthesized on a large scale. The directional growth of twins led the tetrapod nanostructure to be formed. The silicon powder was responsible for the growth of the hollow tetrapods. The UV-visible absorption spectra of the hollow CdSe tetrapods display an absorption edge at about 765 nm. There is a redshift of 53 nm of the absorption edge, in comparison with that of bulk CdSe at 712 nm. In the Raman spectra, two new anomalous modes at 250.91 and 493.42 cm-1 are observed. This might originate from the enhanced internal stress of hollow structures.

Wang, Z. Y.; Fang, X. S.; Lu, Q. F.; Ye, C. H.; Zhang, L. D.

2006-02-01

27

The Bismuth Telluride-Bismuth Selenide System.  

National Technical Information Service (NTIS)

These data sheets present a compilation of a wide range of electronic properties for the bismuth telluride-bismuth selenide system. Electrical properties include conductivity, dielectric constant, Hall coefficient, and mobility. Emission data were broken ...

M. Neuberger

1966-01-01

28

Electronic Transport in Exfoliated Bismuth Selenide  

NASA Astrophysics Data System (ADS)

Recent theoretical and experimental work has identified bismuth selenide as a promising candidate for studies of three-dimensional topological insulators due to its large bulk semiconducting gap crossed by topological Dirac surface states. We report on the fabrication and measurement of mesoscale exfoliated bismuth selenide devices, including the effects of electric-field-effect gating and magnetic field on transport and possible signatures of topological states. We will also discuss fabrication strategies to mitigate surface disorder and doping

Bestwick, Andrew; Williams, James; Gallagher, Patrick; Goldhaber-Gordon, David; Analytis, James; Fisher, Ian

2011-03-01

29

Electronic Transport in Exfoliated Bismuth Selenide  

Microsoft Academic Search

Recent theoretical and experimental work has identified bismuth selenide as a promising candidate for studies of three-dimensional topological insulators due to its large bulk semiconducting gap crossed by topological Dirac surface states. We report on the fabrication and measurement of mesoscale exfoliated bismuth selenide devices, including the effects of electric-field-effect gating and magnetic field on transport and possible signatures of

Andrew Bestwick; James Williams; Patrick Gallagher; David Goldhaber-Gordon; James Analytis; Ian Fisher

2011-01-01

30

Diffusion of iron in gallium selenide  

SciTech Connect

The temperature dependence of the diffusion coefficient of iron in gallium selenide with a defective sphalerite lattice was studied in the range 98-450 C. Iron 55 and Iron 59, in the form of an iron chloride solution, were used as tracers. The activation energies of fast and slow diffusion in alpha-Ga/sub 2/Se/sub 3/ were determined to be, respectively, 25.1 and 21.2 kJ/mole.

Firsova, L.P.

1987-02-01

31

Solvothermal synthesis of bismuth selenide nanotubes  

Microsoft Academic Search

Bismuth selenide (Bi2Se3) nanotubes have been synthesized for the first time using dimethyl formamide (DMF) by solvothermal method. Ammonium bismuth citrate (C24H20Bi14O28,6NH3,10H2O), elemental selenium (Se) and DMF when treated solvothermally in an autoclave at 165 °C formed Bi2Se3 nanocrystals of different morphologies. The morphological modifications are found to depend on the duration of heat treatment and the relative proportions of

Sudip K. Batabyal; C. Basu; A. R. Das; G. S. Sanyal

2006-01-01

32

Synthesis of diorganyl selenides mediated by zinc in ionic liquid.  

PubMed

A new approach for the synthesis of diorganyl selenides is described. By using economically attractive zinc dust in BMIM-BF(4), a series of diorganyl selenides were efficiently achieved in excellent yields, under neutral reaction conditions. Compared to the usual organic solvents, BMIM-BF(4) exhibited higher performance with the advantage to be reused up to five successive runs. PMID:20438119

Narayanaperumal, Senthil; Alberto, Eduardo E; Gul, Kashif; Rodrigues, Oscar E D; Braga, Antonio L

2010-06-01

33

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

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

34

The electrochemical oxidation of organic selenides and selenoxides  

SciTech Connect

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.

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

1997-06-01

35

Ternary and quaternary selenide crystals for nonlinear optical applications  

NASA Astrophysics Data System (ADS)

We have developed several binary, ternary and quaternary sulfide and selenide crystals for nonlinear optical applications and present an overview on the crystal growth and characterization of crystals for nonlinear optical (NLO) conversion efficiency. We have summarized the performance of silver gallium selenide (AgGaSe2), thallium arsenic selenide (Tl3AsSe3), and silver gallium germanium selenide (AgGaGe3Se8 and AgGaGe5Se12) crystals and have compared with gallium selenide (GaSe). All these crystals were grown by vertical Bridgman method in quartz ampoules by using stoichiometric compounds synthesized from constituent elements. The significant problem of cleaving of GaSe was reduced in ternary and quaternary compounds. Experimental results showed that binary, ternary and quaternary selenide compounds transmit at wavelengths up to 16 ?m, have reasonably high value of nonlinear conversion merit (d2/n3, where d is the NLO coefficient and n is the refractive index) and have the lowest absorption coefficient compared to arsenides, phosphides and other nonlinear optical (NLO) materials.

Singh, N. B.; Knuteson, D. J.; Kanner, G.; Berghmans, A.; Green, K.; Wagner, B.; Kahler, D.; King, M.; McLaughlin, S.

2011-09-01

36

The Diorganoselenium and Selenides Compounds Electrochemistry  

PubMed Central

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.

Tepecik, Abdulkadir; Altin, Zehra; Erturan, Seyfettin

2008-01-01

37

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

PubMed

Luminescent quantum dots were synthesized using bacterially derived selenide (Se(II-)) as the precursor. Biogenic Se(II-) 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 ?-mercaptoethanol-stabilized ZnSe nanoparticles by aqueous synthesis. Biological Se(II-) 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 Se(II-) 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 Se(II-) 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. PMID:23508116

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

2013-03-18

38

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

NASA Astrophysics Data System (ADS)

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.

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

39

Electroluminescence in zinc sulpho-selenide and in zinc sulphide  

Microsoft Academic Search

Light-emitting devices with electrode areas of 1 mm2 have been prepared on single crystals of solid solutions of zinc selenide and zinc sulphide. It is shown that it is relatively easy to prepare ohmic contacts with indium on samples containing lp to 80% molar of sulphur. The most intense electroluminescence has been obtained from devices carrying one indium and one

M. E. Ozsan; J. Woods

1977-01-01

40

Density of thin vapour-deposited films of zinc selenide  

Microsoft Academic Search

The density of thin vapour-deposited films of zinc selenide was determined by spectrophotometry combined with Rutherford backscattering spectrometry. Bulk stoichiometry of the films was measured by Rutherford backscattering spectroscopy. It was found that the films were relatively rich in Se. Depth profile study of the films, by x-ray photoelectron spectroscopy, revealed that surfaces were rich in Se while, away from

E. E. Khawaja; S. M. A. Durrani; A. B. Hallak; M. A. Salim; M. S. Hussain

1994-01-01

41

Semiconducting thin films of zinc selenide quantum dots  

Microsoft Academic Search

A novel chemical route for deposition of zinc selenide quantum dots in thin film form is developed. The deposited films are characterized with very high purity in crystallographic sense, and behave as typical intrinsic semiconductors. Evolution of the average crystal size, lattice constant, lattice strain and the optical properties of the films upon thermal treatment is followed and discussed. The

Biljana Pejova; Atanas Tanusevski; Ivan Grozdanov

2004-01-01

42

Synthesis and characterization of poly( N-vinylpyrrolidine)-silica hybrid shell coated cadmium selenide \\/ cadmium sulphide and cadmium selenide \\/ zinc sulfide nanoparticles  

Microsoft Academic Search

Poly(N-vinylpyrrolidine)-silica hybrid shell coated cadmium selenide \\/ cadmium sulphide and cadmium selenide \\/ zinc sulfide nanoparticles were synthesized by combining the organometallic and single “step” modified Stober method. The synthesized nanoparticles were characterized by atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, and a spectrofluorometer. Concluding, this report has provided important insights into the design of new water-soluble polymer

Kaliyaperumal Viswanathan; C. Bor Fuh

2011-01-01

43

Fabrication of core-shell-type copper indium selenide and zinc selenide composite quantum dots and their optical properties.  

PubMed

We successfully fabricated core/shell-type composite QDs based on the ternary-CuInSe2. For the CuInSe2/ZnSe core/shell QDs, an enhanced photoluminescence (PL) emission intensity, such as 16% of the photoluminescence quantum yield (PLQY), and a blue-shift in the emission after the ZnSe coating, were observed. The increase in the PLQY was the result of an exchange of the surface capping ligand from the organic hexadecylamine to the inorganic ZnSe and the smoothing of the confining profile due to the alloying. The blue-shift was attributed to the shrinkage of the effective size of the core-CuInSe2 region due to the partial alloying of the core-CuInSe2 with the ZnSe-shell around their interfaces. For the inverted core/shell QDs, i.e., the nominally ZnSe/CuIn5Se8 core/shell QDs, they showed a red emission at 619 nm. The emission wavelength is the shortest among the previously reported QDs in Cu-In-Se system. PMID:21770109

Omata, Takahisa; Nosel, Katsuhiro; Otsuka-Yao-Matsuo, Shinya

2011-06-01

44

Keeping Track of the Selenide zoo. A Combined Optical Microscopy - EPMA Study of Complex Selenides  

NASA Astrophysics Data System (ADS)

Hunting for new mineral phases is a fascinating scientific activity. This kind of research not only serves the replenishment of mineralogy textbooks with new mineral names but also the industry with new potential semiconductors, laser crystals and other 'high-tech phases'. Chemical analyses using the electron microprobe are an essential intermediate step in the course of the description of a new mineral. The study of a great number of different Cu-Pb-Ag-As-Hg-Tl-Sb-Bi-Cd selenides from the former uranium deposit Schlema-Alberode (Saxony) in the German part of the Erzgebirge represented a twofold challenge to us. The complex genetic and age relations of the ore minerals and gangue minerals entailed the development of very complex microstructures in a tight space. Typical features are symplectitic intergrowths, exsolutions, fine lamellae, zoned crystals and the development of pseudo- and paramorphs. Altogether we found 34 different selenide, sulfide and arsenide minerals, including 6 dimorpheous phases. Many of these minerals are indistinguishable by electron-optical methods used during different stages of the study. Dimorpheous minerals like bellidoite and berzelianite are as much indistinguishable like intergrowths of the minerals berzelianite, mgriite and lollingite using backscattered and secondary electron images. Optical microscopy is the key to overcome these problems. We show that the step-by-step combination of polarized light microscopy, phase contrast microscopy and differential interference contrast microscopy using transmitted and reflected light allowed a secure discrimination of the different minerals and unknown phases. 16 elements are incorporated into these phases either as main, minor or trace elements. A multitude of overlapping peaks, potenzial fluorescence effects caused by adjacent phases and different matrices in the minerals demanded the development of several specific methods optimized for the analysis of Pb-Se-, Cu-Tl-Se-, Cu-Fe-Zn-As-Se-, Hg-Pb-Ag-Se-, and arsenide phases. The electron microprobe studies will be followed by EBSD, TEM and crystal structure determination by X-ray diffraction using ultra-small amounts of material taken with the help of a New Wave micromill.

Schlothauer, T.; Renno, A. D.; Heide, G.

2007-12-01

45

Convenient synthesis of unsymmetrical organochalcogenides using organoboronic acids with dichalcogenides via cleavage of the S-S, Se-Se, or Te-Te bond by a copper catalyst.  

PubMed

This article describes the methodology for a copper-catalyzed preparation of numerous monochalcogenides from dichalcogenides with organoboronic acids. Unsymmetrical diorgano-monosulfides, selenides, and tellurides can be synthesized by the coupling of dichalcogenides with aryl- or alkylboronic acids using a copper catalyst in air. The present reaction can take advantage of both organochalcogenide groups on dichalcogenide. PMID:17288374

Taniguchi, Nobukazu

2007-02-16

46

Synthesis and shape evolution of bismuth selenide hollow nanospheres  

Microsoft Academic Search

Uniform bismuth selenide hollow nanospheres were synthesized on a large scale in a mixed solvent of ethylene glycol (EG) and oleic acid (OA). The diameter of the Bi2Se3 hollow nanospheres is about 600 nm and the thickness of the shell is about 40 nm. The shape evolution of Bi2Se3 nanostructures with different volume ratios of EG and OA was also

Jun Li; Yongchun Zhu; Jin Du; Junhao Zhang; Yitai Qian

2008-01-01

47

Solvothermal synthesis and thermoelectric property of nanostructured bismuth selenide  

Microsoft Academic Search

Bismuth selenide (Bi2Se3) nanostructures were synthesized via solvothermal method. The crystallinity of the as-prepared sample has been analyzed by X-ray diffraction, which shows the formation of rhombohedral Bi2Se3. Electron microscopy examination shows that the Bi2Se3 nanostructures have hexagonal plate like structure. The effect of the synthesis temperatures on the structure and morphology of the nanostructures has also been investigated. It

Kamal Kadel; Latha Kumari; Wenzhi Li; Jianu Huang; Paula P. Provencio; Zhifeng Ren

2010-01-01

48

Strong quantum confinement effects in thin zinc selenide films  

Microsoft Academic Search

Thin Zinc Selenide films in the thickness range 3–50nm have been prepared on high quality glass substrates by e-beam evaporation under ultrahigh vacuum conditions. Optical absorption spectroscopy experiments reveal a systematically increasing blue shift of the effective bandgap energy as the film thickness decreases, reaching a maximum value of 0.32eV for the thinner film. The experimental results, which indicate the

S. Baskoutas; P. Poulopoulos; V. Karoutsos; M. Angelakeris; N. K. Flevaris

2006-01-01

49

The unexpected properties of alkali metal iron selenide superconductors  

SciTech Connect

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

Dagotto, Elbio R [ORNL

2013-01-01

50

Colloquium: The unexpected properties of alkali metal iron selenide superconductors  

NASA Astrophysics Data System (ADS)

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.

Dagotto, Elbio

2013-04-01

51

Organoselenium bis selenide attenuates 3-nitropropionic acid-induced neurotoxicity in rats.  

PubMed

This study was designed to evaluate the effects of bis selenide on Huntington disease (HD)-like signs induced by 3-nitropropionic acid (3-NP) in rats. To this aim, rats were treated for 4 days with bis selenide (5 or 20 mg/kg/day, per oral) 30 min before 3-NP (20 mg/kg/day, intraperitoneally). The body weight gain, locomotor activity, motor coordination, and biochemical parameters in striatal preparations were assessed 24 h after the last injection of 3-NP. The highest dose of bis selenide was effective in protecting against body weight loss and motor coordination deficit induced by 3-NP. The impairment of locomotor activity caused by 3-NP was abolished by bis selenide at both doses. Bis selenide (5 and 20 mg/kg) partially restored succinate dehydrogenase activity inhibited after 3-NP exposure. The dose of 20 mg/kg of bis selenide recovered partially ?-aminolevulinic acid dehydratase activity, and totally Na(+), K(+)-ATPase activity, two sulfhydryl enzymes sensitive to oxidizing agents, which had their activities inhibited by 3-NP. Also, 3-NP led to an increase in protein carbonyl levels and glutathione reductase activity and inhibited catalase activity-alterations that were reversed by bis selenide administration at both doses. The highest dose of bis selenide was effective against the increase of RS levels, the depletion of reduced glutathione content, and the inhibition of glutathione peroxidase activity induced by 3-NP. Bis selenide was not effective against inhibition of SOD activity caused by 3-NP. These findings demonstrate that bis selenide elicited protective effects against HD-like signs induced by 3-NP in rats. PMID:22739838

Bortolatto, Cristiani F; Jesse, Cristiano R; Wilhelm, Ethel A; Chagas, Pietro M; Nogueira, Cristina W

2012-06-28

52

Neutron Scattering Study on the New 245 Iron Selenide Superconductors  

NASA Astrophysics Data System (ADS)

We determine using neutron and x-ray diffraction method the sample composition, crystalline structure and magnetic order of the recently discovered A2Fe4Se5 superconductors (A=K, Rb, Cs, Tl/K or Tl/Rb). Contrary to initial belief that these materials are heavily electron-doped variety of the BaFe2As2 family of Fe-based superconductors, they are almost charge balanced with the Fe valence close to 2+ as in the 11 iron selenide superconductors, and crystalize in an Fe vacancy-ordered lattice structure [1,2]. Coexisting with superconductivity is a novel block antiferromagnetic order which conforms to the tetragonal crystalline symmetry and possesses a very large ordered magnetic moment 3.3?B per Fe and a very high ordering temperature above 500 K [1]. Such Fe vacancy ordered crystal structure and coexisting antiferromagnetism and superconductivity occur in all 5 types of new iron selenide superconductors discovered so far. With Fe vacancy number departs from the chemical formulas A2Fe4Se5, an imperfect version of the Fe vacancy order results at base temperature while phase separation into two vacancy-ordered phases exists at the intermediate temperature range [4]. The Fe site disorder renders the materials insulating and destroys the superconductivity as spin-glass disorder does in previous 11 iron selenide superconductors [5]. [4pt] [1] W. Bao et al., Chin. Phys. Lett. 28, 086104 (2011).[0pt] [2] P. Zavalij etal., Phys. Rev. B 83, 132509 (2011).[0pt] [3] F. Ye et al., Phys. Rev. Lett. 107 137003 (2011).[0pt] [4] W. Bao et al., arXiv: 1102.3674 (2011).[0pt] [5] T.J. Liu et al., Nat. Materials 9, 716 (2010).

Bao, Wei

2012-02-01

53

Fractal simulation of the resistivity and capacitance of arsenic selenide  

SciTech Connect

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.

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

54

Copper Test  

MedlinePLUS

... 3. What happens if I am exposed to toxic amounts of copper? Copper poisoning can cause vomiting ... Asked Questions American Cancer Society: Copper Agency for Toxic Substances and Disease Registry: Public Health Statement for ...

55

Selenide Isotope Generator for the Galileo Mission. Quality Assurance Program Plan.  

National Technical Information Service (NTIS)

This Quality Program Plan has been prepared to describe the quality activities associated with the development, production, test and delivery of hardware for the Selenide Isotope Generator Program. The objective of the Quality Program Plan is to establish...

1978-01-01

56

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

Microsoft Academic Search

Chemical bath deposition techniques for bismuth sulfide, bismuth selenide, antimony sulfide, and antimony selenide thin films of about 0.20 - 0.25 micrometer thickness are reported. All these materials may be considered as solar absorber films: strong optical absorption edges, with absorption coefficient, (alpha) , greater than 104 cm-1, are located at 1.31 eV for Bi2Se3, 1.33 eV for Bi2S3, 1.8

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

1997-01-01

57

Synthesis and optical properties of single-crystalline bismuth selenide nanorods via a convenient route  

NASA Astrophysics Data System (ADS)

Single-crystalline bismuth selenide nanorods were synthesized on a large scale by a convenient solvothermal method. The as-prepared bismuth selenide was investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and UV Vis Spectrophotometer. And a possible formation mechanism was proposed. The band gap of the as-prepared Bi2Se3 nanorods is about 1.5 eV, indicating a blue-shift phenomenon relative to the bulk.

Yang, Xiaohong; Wang, Xiong; Zhang, Zude

2005-04-01

58

Synthesis and optical properties of single-crystalline bismuth selenide nanorods via a convenient route  

Microsoft Academic Search

Single-crystalline bismuth selenide nanorods were synthesized on a large scale by a convenient solvothermal method. The as-prepared bismuth selenide was investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and UV–Vis Spectrophotometer. And a possible formation mechanism was proposed. The band gap of the as-prepared Bi2Se3 nanorods is about 1.5eV, indicating a blue-shift phenomenon relative to

Xiaohong Yang; Xiong Wang; Zude Zhang

2005-01-01

59

Photoinduced synthesis of unsymmetrical diaryl selenides from triarylbismuthines and diaryl diselenides  

PubMed Central

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.

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

2013-01-01

60

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

Microsoft Academic Search

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

P. K. Khanna; B. K. Das

2004-01-01

61

Phase Separation and Magnetic Order in K-doped Iron Selenide Superconductor  

Microsoft Academic Search

Alkali-doped iron selenide is the latest member of high Tc superconductor family, and its peculiar characters have immediately attracted extensive attention. We prepared high-quality potassium-doped iron selenide (KxFe2-ySe2) thin films by molecular beam epitaxy and unambiguously demonstrated the existence of phase separation, which is currently under debate, in this material using scanning tunneling microscopy and spectroscopy. The stoichiometric superconducting phase

Wei Li; Hao Ding; Peng Deng; Kai Chang; Canli Song; Ke He; Lili Wang; Xucun Ma; Jiang-Ping Hu; Xi Chen; Qi-Kun Xue

2011-01-01

62

Hybrid Bismuth Selenide Nanostructures Synthesized by Chemical Vapor Deposition  

NASA Astrophysics Data System (ADS)

The recent demonstration of theoretically predicted topologically ordered states in real bismuth based chemical compounds such as bismuth antimony, bismuth selenide, bismuth telluride etc opened the field of topological insulators (materials exhibiting insulator properties in bulk, but metallic behavior on the surface) for a plethora of possible applications. Topological insulator nanostructures in particular are of great interest due to their large surface to volume ratio. We will report on the CVD synthesis of various hybrid 1D and 2D nanostructures of the bismuth-selenium complex, and their morphological and structural properties (investigated by SEM and TEM imaging coupled with EDAX and XRD spectroscopy). Optical and transport properties will be also presented and related to possible spintronics and no dissipation electronics applications.

Panaitescu, Eugen; Liu, Fangze; Kar, Swastik; Menon, Latika

2012-02-01

63

Solvothermal synthesis and thermoelectric property of nanostructured bismuth selenide  

NASA Astrophysics Data System (ADS)

Bismuth selenide (Bi2Se3) nanostructures were synthesized via solvothermal method. The crystallinity of the as-prepared sample has been analyzed by X-ray diffraction, which shows the formation of rhombohedral Bi2Se3. Electron microscopy examination shows that the Bi2Se3 nanostructures have hexagonal plate like structure. The effect of the synthesis temperatures on the structure and morphology of the nanostructures has also been investigated. It is found that the particle size increases with the synthesis temperature. Thermoelectric properties of Bi2Se3 nanostructures have also been measured. A maximum figure-of-merit (ZT) of 0.096 was obtained at 523K and a minimum thermal conductivity of 0.751Wm-1K-1 at 300K.

Kadel, Kamal; Kumari, Latha; Li, Wenzhi; Huang, Jianu; Provencio, Paula P.; Ren, Zhifeng

2010-03-01

64

Synthesis and characterization of nanostructured bismuth selenide thin films.  

PubMed

Nanostructured bismuth selenide thin films have been successfully fabricated on a silicon substrate at low temperature by rational design of the precursor solution. Bi(2)Se(3) thin films were constructed of coalesced lamella in the thickness of 50-80 nm. The nucleation and growth process of Bi(2)Se(3) thin films, as well as the influence of solution chemistry on the film structure were investigated in detail. As one of the most promising thermoelectric materials, the thermoelectric properties of the prepared Bi(2)Se(3) thin films were also investigated. The power factor increased with increasing carrier mobility, coming from the enlarged crystallites and enhanced coalesced structure, and reached 1 ?W cm(-1) K(-1). PMID:20949202

Sun, Zhengliang; Liufu, Shengcong; Chen, Lidong

2010-10-15

65

Nanopatterned cadmium selenide Langmuir-Blodgett platform for leukemia detection.  

PubMed

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

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

2012-03-16

66

Boron selenide semiconductor detectors for thermal neutron counting  

NASA Astrophysics Data System (ADS)

Thermal neutron detectors in planar configuration were fabricated from B2Se3 (Boron Selenide) crystals grown at RMD Inc. All fabricated semiconductor devices were characterized for the current-voltage (I-V) characteristic and neutron counting measurement. In this study, the resistivity of crystals is reported and the collected pulse height spectra are presented for devices irradiated with the 241AmBe neutron source. Long-term stability of the B2Se3 devices for neutron detection under continuous bias and without being under continuous bias was investigated and the results are reported. The B2Se3 devices showed response to thermal neutrons of the 241AmBe source.

Kargar, Alireza; Tower, Joshua; Cirignano, Leonard; Shah, Kanai

2013-09-01

67

Pressure-driven quantum criticality in iron-selenide superconductors.  

PubMed

We report a finding of a pressure-induced quantum critical transition in K0.8Fe(x)Se2 (x = 1.7 and 1.78) superconductors through in situ high-pressure electrical transport and x-ray diffraction measurements in diamond anvil cells. Transitions from metallic Fermi liquid behavior to non-Fermi liquid behavior and from antiferromagnetism to paramagnetism are found in the pressure range of 9.2-10.3 GPa, in which superconductivity tends to disappear. The change around the quantum critical point from the coexisting antiferromagnetism state and the Fermi liquid behavior to the paramagnetism state and the non-Fermi liquid behavior in the iron-selenide superconductors demonstrates a unique mechanism for their quantum critical transition. PMID:23003077

Guo, Jing; Chen, Xiao-Jia; Dai, Jianhui; Zhang, Chao; Guo, Jiangang; Chen, Xiaolong; Wu, Qi; Gu, Dachun; Gao, Peiwen; Yang, Lihong; Yang, Ke; Dai, Xi; Mao, Ho-kwang; Sun, Liling; Zhao, Zhongxian

2012-05-08

68

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

SciTech Connect

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.

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

1987-09-01

69

Amphoteric nature of copper impurities in Bi 2 Se 3 crystals  

Microsoft Academic Search

ReflectivityR(?) in infrared spectral region was measured on bismuth selenide crystals Bi2Se3(Cu) doped with copper and on the crystals Bi2Se3(2Cu+3Se) doped with copper and selenium in atomic ratio 2:3. Bi2Se3(Cu) crystals exhibit a pronounced shift of the reflectivity minimum towards shorter wavelengths, as compared with “pure”\\u000a Bi2Se3, whereas in the Bi2Se3(2Cu+3Se) crystals the reflectivity minimum is shifted towards longer wavelengths,

A. Vasko; L. Tichý; J. Horák; J. Weissenstein

1974-01-01

70

Copper Indium Gallium Selenide (CIGS) Photovoltaic Devices Made Using Multistep Selenization of Nanocrystal Films.  

PubMed

The power conversion efficiency of photovoltaic devices made with ink-deposited Cu(InxGa1-x)Se2 (CIGS) nanocrystal layers can be enhanced by sintering the nanocrystals with a high temperature selenization process. This process, however, can be challenging to control. Here, we report that ink deposition followed by annealing under inert gas and then selenization can provide better control over CIGS nanocrystal sintering and yield generally improved device efficiency. Annealing under argon at 525 °C removes organic ligands and diffuses sodium from the underlying soda lime glass into the Mo back contact to improve the rate and quality of nanocrystal sintering during selenization at 500 °C. Shorter selenization time alleviates excessive MoSe2 formation at the Mo back contact that leads to film delamination, which in turn enables multiple cycles of nanocrystal deposition and selenization to create thicker, more uniform absorber films. Devices with power conversion efficiency greater than 7% are fabricated using the multiple step nanocrystal deposition and sintering process. PMID:23957691

Harvey, Taylor B; Mori, Isao; Stolle, C Jackson; Bogart, Timothy D; Ostrowski, David P; Glaz, Micah S; Du, Jiang; Pernik, Douglas R; Akhavan, Vahid A; Kesrouani, Hady; Vanden Bout, David A; Korgel, Brian A

2013-09-05

71

Differences in copper indium selenide films obtained by electron beam and flash evaporation  

Microsoft Academic Search

Two alternative crystal structures have been identified in evaporated films grown from synthesized CuInSe2. The first one, tetragonal CuInSe2 was obtained by ‘flash’ evaporation and the second one, the ordered vacancy compound CuIn2Se3.5 by e-beam evaporation. They had optical gaps of 1.0 for the first and 1.24 eV for the second. The conductivities were p- and n-type, respectively; the last

S. I. Castañeda; F. Rueda

2000-01-01

72

Change in microhardness of copper selenide upon transition to the superionic phase  

SciTech Connect

We investigated the microhardness H of samples of Cu/sub 2-x/Se (x = 0-0.3) in the temperature interval 220-470 K. We observed an anomalous decrease in the microhardness of Cu/sub 2-x/Se samples (x = 0-0.3) upon transition to the superionic ..beta.. phase (T/sub c/ = 291-413 K), connected with a special state (intermediate between solid and liquid) of the superionic phase of the substance.

Korzhuev, M.A.; Korol'kova, I.G.; Abrikosov, N.Kh.

1988-05-01

73

Ternary cadmium sulphide selenide quantum dots as new scintillation materials  

SciTech Connect

Monodisperse, highly luminescent, zinc blende, cadmium sulphide selenide (CdS{sub x}Se{sub 1-x}, x=mole fraction of sulphur) quantum dots (QDs) were prepared in gram scales in the particle size range 2?6-4?3 nm. With the varying S and Se contents, emission wavelengths of CdS{sub x}Se{sub 1-x} QDs were tuned from 439 to 581 nm (?exc.=370 nm). QDs were well dispersed in organic solvents and optically transparent plastic scintillators made with up to 10 wt-%QDs in polyvinyltoluene (PVT) were prepared. The result from alpha particle detection indicated the wavelengths match with the sensitivity of the photomultiplier tube. Pulse height peaks of CdS{sub x}Se{sub 1-x} with the wavelength of emission from 439 to 482 nm, appeared around 0?35 (channel no./amplifier gain), with different photon counts. No pulse height peak was observed with QDs that emitted at 505 nm or longer wavelengths. Under studied conditions, CdS0?95Se0?05 was found to be the most efficient scintillator.

Brown, Suree [ORNL; Dai, Sheng [ORNL; Rondinone, Adam Justin [ORNL

2008-01-01

74

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

SciTech Connect

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.

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

75

Structural characterization of hot wall deposited cadmium selenide thin films  

NASA Astrophysics Data System (ADS)

Cadmium selenide (CdSe) films were prepared by the hot wall deposition technique with different quartz tube lengths under a vacuum of 6.6 mPa onto well cleaned glass substrates to optimize the tube length. The XRD analysis revealed that the films were polycrystalline in nature for smaller tube lengths and for smaller thicknesses, but with increasing thickness and increasing tube lengths a preferred orientation was observed on all substrates. The x-ray diffractograms of the films coated on 0.07 m length tube exhibit preferential orientation along the (103) direction for smaller thicknesses, which changes to the (002) direction as the thickness increases, but the films coated with other tube lengths show preferential orientation along the (002) plane parallel to the substrate at larger thicknesses. The lattice constants and the structural parameters viz., crystallite size (D), dislocation density 0268-1242/13/9/009/img7 and strain 0268-1242/13/9/009/img8, were calculated for all the films and it was found that as the tube length increases the grain size and strain decreases up to 0.13 m tube length and increases for 0.15 m tube length. The effects of the substrate were studied by coating the film on steatite, mica and ITO substrates using an optimized tube length (0.15 m). Films coated on glass, mica and ITO have a very smooth surface finish, reflecting like a mirror, and those on steatite have a matt finish. Depending on the adhesiveness and grain size the substrates were chosen for further applications. Studies on the effect of substrate temperature were carried out on the films obtained using 0.15 m quartz tube length. From Rutherford backscattering spectrometry analysis, it was found that as the tube length increases the Cd/Se ratio approaches unity.

Velumani, S.; Narayandass, Sa K.; Mangalaraj, D.

1998-09-01

76

Superconducting phases in potassium-intercalated iron selenides.  

PubMed

The ubiquitous coexistence of majority insulating 245 phases and minority superconducting (SC) phases in A(x)Fe(2-y)Se(2) (A = K, Cs, Rb, Tl/Rb, Tl/K) formed by high-temperature routes makes pure SC phases highly desirable for studying the intrinsic properties of this SC family. Here we report that there are at least two pure SC phases, K(x)Fe(2)Se(2)(NH(3))(y) (x ? 0.3 and 0.6), determined mainly by potassium concentration in the K-intercalated iron selenides formed via the liquid ammonia route. K(0.3)Fe(2)Se(2)(NH(3))(0.47) corresponds to the 44 K phase with lattice constant c = 15.56(1) Å and K(0.6)Fe(2)Se(2)(NH(3))(0.37) to the 30 K phase with c = 14.84(1) Å. With higher potassium doping, the 44 K phase can be converted into the 30 K phase. NH(3) has little, if any, effect on superconductivity. Thus, the conclusions should apply to both K(0.3)Fe(2)Se(2) and K(0.6)Fe(2)Se(2) SC phases. K(0.3)Fe(2)Se(2)(NH(3))(0.47) and K(0.6)Fe(2)Se(2)(NH(3))(0.37) stand out among known superconductors as their structures are stable only at particular potassium doping levels, and hence the variation of T(c) with doping is not dome-like. PMID:23406203

Ying, Tianping; Chen, Xiaolong; Wang, Gang; Jin, Shifeng; Lai, Xiaofang; Zhou, Tingting; Zhang, Han; Shen, Shijie; Wang, Wanyan

2013-02-19

77

Temperature and field effects on reflectivity of gallium selenide surface  

NASA Astrophysics Data System (ADS)

Monocrystals of gallium selenide (GaSe) has recently attracted significant attention in the field of new optoelectronic devices, due to the original combination of its specific features such as nonlinear optical properties, layered structure and high-photo sensitivity. GaSe crystals show both high reflectivity and unique surface perfection, which leads to a promising candidate for next generation optical devices. We will present our experimental results of reflection spectra of such crystals for various temperatures (273°K-383°K) and applied electric field (1 V/cm - 20 V/cm). The reflection spectra were analyzed to identify the mechanism of the reflective coefficient change in GaSe as a function of wavelength, temperature and electric field. This study will identify the optimal electrical field regimes and spectral segments, where we experimentally revealed reflective properties of GaSe are suitable for creating the field regulated optical applications of decoder and depolarizer. The temperature dependence of GaSe reflectance spectrum, its temperature and applied field dependences exemplified that the processes of photon-electron inter-exchanging on the surfaces are dominated over the bulk processes in forming the reflectance properties of layered crystals. The perfectness of natural surface and their high reflective properties weren't changed in the interval of experimental temperatures. The monolayer surface of GaSe can be utilized as an easy prepared natural plane surface for new optical devices on their surface basis in their original combinations. Such devises are applicable for optical information processing systems because of the stability function and weak dependence of the function of bulk properties.

Alhasson, Bader; Hajiyev, Yashar; Matin, Mohammad

2008-08-01

78

Living bio-membrane bi-template route for simultaneous synthesis of lead selenide nanorods and nanotubes  

NASA Astrophysics Data System (ADS)

In this paper, a novel method is reported by which semiconductor materials are synthesized via controlled organism membranes. Semiconductor lead selenide nanorods and nanotubes have been successfully prepared simultaneously through living bio-membrane bi-templates of the mungbean sprout. The lead selenide nanorods are approximately 45 nm in diameter, and up to 1100 nm in length; all of them are single crystalline in structure. Lead selenide nanotubes are 50 nm in diameter, and up to 2000 nm in length, and are poly-crystalline in structure. The characteristics of the products are illustrated by various means, and their possible formation mechanism is explored.

Li, Li; Wu, Qing-Sheng; Ding, Ya-Ping

2004-12-01

79

Axisymmetric deformation of a circular cylinder of piezoelectric cadmium selenide crystal  

Microsoft Academic Search

This paper deals with the axisymmetric deformations in a circular cylinder of finite length made of Piezoelectric, crystalline cadmium selenide belonging to class 6mm. The displacements and the electric potential are expressed in terms of a single function. Displacements and electric potential prescribed on the lateral surfaces are expanded in Fourier series, and the stresses and the electric potential prescribed

B. Srinivasa Rao; H. S. Paul

1969-01-01

80

Apoptosis induced by cadmium selenide quantum dots in JB6 cells.  

PubMed

Quantum dots are being widely used in physics and in the biomedical industry in recent years due to their excellent optical characteristics. However, studies have shown that cadmium selenide core-shell quantum dots exhibit cytotoxicity. The present study investigates the induction of apoptosis and the signal pathways involved in this process by cadmium selenide-core quantum dots in JB6 cells. We found that cadmium selenide-core quantum dots exhibited high cytotoxicity and caused apoptosis and necrosis of JB6 cells. Cell cycle detection showed an increase in the percentage of G1 phase cells but a decrease in the percentage of S and G2 phase cells after JB6 cells treated with various concentrations of cadmium selenide core-shell quantum dots for 24 h. At the same time, western-blot analysis showed an activation of pro-apoptotic factors including FAS, BAX and BID. Apoptosis-inducing factor (AIF), full length and cleaved caspase-6 and -8 were up-regulated. The current study provides a guide for the safe use of QDs as a new kind of biological fluorescence material for biological and medical applications. PMID:23421204

Kong, Lu; Zhang, Ting; Tang, Meng; Pu, Yuepu

2012-11-01

81

Anomalous Diffusion of Nickel in Single Crystals of Lead Selenide at 700C.  

National Technical Information Service (NTIS)

The diffusion of nickel into undoped and silver-doped, p-type lead selenide crystals exhibits anomalous behavior at 700C. The penetration profiles show pronounced minima and these minima migrate into the crystal as a function of time. The minima occur whe...

B. Swaroop J. B. Wagner

1968-01-01

82

Photochemical synthesis of bismuth selenide nanocrystals in an aqueous micellar solution.  

PubMed

The photolytic decomposition of triphenylbismuth and di-tert-butyl diselenide under aqueous micellar conditions yields 5-nm bismuth selenide nanocrystals of the BiSe stoichiometry. This is the first example of the bismuth-rich BiSe phase being prepared in a well-dispersed colloidal nanocrystal form. PMID:21235268

Webber, David H; Brutchey, Richard L

2011-01-05

83

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

Microsoft Academic Search

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

Don Berlincourt; Hans Jaffe; L. R. Shiozawa

1963-01-01

84

Dispersion strengthened copper  

DOEpatents

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

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

1990-01-01

85

Dispersion strengthened copper  

DOEpatents

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

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

1989-01-01

86

R and D on the Application of Polycrystalline Zinc Selenide and Cadmium Telluride to High Energy IR Laser Windows.  

National Technical Information Service (NTIS)

Theoptical absorption of previously available polycrystalline zinc selenide and cadmium telluride was too extensive to permit the use of these materials in high energy laser windows. The approach used in the program was to make polycrystalline windows by ...

C. R. Porter D. W. Roy M. W. Benecke

1972-01-01

87

Efficient Generation of Spin Current and Spin Transfer Torque by the Topological Insulator Bismuth Selenide  

NASA Astrophysics Data System (ADS)

We study the use of topological insulators as a source of spin current for applying spin transfer torque to a ferromagnet. We fabricate bismuth selenide / permalloy bilayers and use the spin-torque FMR technique to make quantitative measurements of the torque applied to the magnetic permalloy layer resulting from an in-plane current. Despite the fact that only a small fraction of the current flows in the bismuth selenide, we still observe large spin torque effects. There is a component of torque in the sample plane with the symmetry expected from the spin Hall effect, with a strength corresponding to a spin Hall angle greater than 1, larger than measured for any other material. There is also an additional out-of-plane, field-like torque several times larger than expected from the Oersted field. We will discuss the dependence of these effects on layer thickness, and attempt to distinguish whether they result from bulk or surface-state effects.

Mellnik, Alex; Grab, Jennifer; Mintun, Peter; Lee, Joon Sue; Richardella, Anthony; Samarth, Nitin; Ralph, Daniel

2013-03-01

88

Biological interaction between transition metals (Ag, Cd and Hg), selenide\\/sulfide and selenoprotein P  

Microsoft Academic Search

The interaction between transition metals (Ag+, Cd2+ and Hg2+) and selenium (Se) in the bloodstream was studied in vitro by means of the HPLC – inductively coupled argon plasma-mass spectrometry (ICP MS) method. Transition metal ions and selenide (produced in vitro from selenite in the presence of glutathione) or sulfide (Na2S) formed a (metal–Se\\/S) complex, which then bound to a

Chieka Sasakura; Kazuo T. Suzuki

1998-01-01

89

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

Microsoft Academic Search

Bismuth tellurium selenide (Bi2TeySe3?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(NO3)3) in water and to favor the reaction with reduced sources of tellurium and selenium. The resulting powder is

Cham Kim; Dong Hwan Kim; Yoon Soo Han; Jong Shik Chung; SangHa Park; Hoyoung Kim

2011-01-01

90

Chemical deposition and characterization of glassy bismuth(III) selenide thin films  

Microsoft Academic Search

Glassy thin films of bismuth(III) selenide were deposited onto glass and polyester substrates using a chemical bath deposition technique. X-Ray diffraction analysis was used for identification of the material obtained. Optical and electrical properties of the films were investigated. According to the resistance–temperature measurements, Bi2Se3 thin films are typical semi-conducting materials with calculated activation energies of 0.2 and 1.1 eV

Biljana Pejova; Ivan Grozdanov

2002-01-01

91

Optical and thermal band gap energy of chemically deposited bismuth(III) selenide thin films  

Microsoft Academic Search

The band gap energy of bismuth(III) selenide in thin-film form was determined using the optical and thermal methods. The optical band gap energy of 0.35eV was calculated on the basis of the recorded optical spectra in the near-infrared region, within the framework of a parabolic approximation for the dispersion relation, using the equations which arise from Fermi’s golden rule for

Biljana Pejova; Ivan Grozdanov; Atanas Tanuševski

2004-01-01

92

Spectroscopic ellipsometry studies on vacuum-evaporated zinc selenide thin film  

NASA Astrophysics Data System (ADS)

Optical constants of vacuum-deposited Zinc selenide (ZnSe) film from far infrared to near ultraviolet spectral region (270nm-30?m) have been determined by variable angle spectroscopic ellipsometry. The surface roughness layer and interface layer between ZnSe film and crystalline silicon have been modeled with Bruggeman effective medium approximation (BEMA). To evaluate the microstructure of ZnSe film, X-ray diffraction (XRD) measurements are also performed.

Gao, Weidong

2009-05-01

93

X-Ray spectroscopic evidence for chemical bonding in manganese selenide (MnSe)  

Microsoft Academic Search

K absorption spectra of manganese and selenium have been recorded photographically in the pure metals and in the intermetallic\\u000a compound manganese selenide (MnSe), employing a bent crystal X-ray spectrograph. It has been observed that the Mn K absorption\\u000a discontinuity in MnSe shifts by 5·6 eV toward the high energy side with respect to the discontinuity in the pure metal. On

Chintamani Mande; A. S. Nigavekar

1967-01-01

94

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

NASA Astrophysics Data System (ADS)

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

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

1997-10-01

95

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

Microsoft Academic Search

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 2–4nm which was well consistent with the size measured by UV analysis. The presence of paramagnetic substance Mn2+ in the ZnSe quantum dots was confirmed by

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

2011-01-01

96

Growth rate of equilibrium-like-shaped single crystals of superionic conductor cuprous selenide  

Microsoft Academic Search

The equilibrium-like-shaped single crystals of nonstoichiometric cuprous selenide were grown in their high-temperature phase from 480 to 530°C using Ohachi's method. The method had been developed for ionic–electronic mixed conductors, involving macroscopic transport of mobile metal atoms through the polycrystalline bulk, due to a fixed chemical potential difference, and utilising capillary narrowing for single-crystal selection. In the solid-state crystallisation mode

Z. Vucic; J Gladi?

1999-01-01

97

Magnesium-induced copper-catalyzed synthesis of unsymmetrical diaryl chalcogenide compounds from aryl iodide via cleavage of the Se-Se or S-S bond.  

PubMed

The methodology for a copper-catalyzed preparation of diaryl chalcogenide compounds from aryl iodides and diphenyl dichalcogenide molecules is reported. Unsymmetrical diaryl sulfide or diaryl selenide can be synthesized from aryl iodide and PhYYPh (Y = S, Se) with a copper catalyst (CuI or Cu(2)O) and magnesium metal in one pot. This reaction can be carried out under neutral conditions according to an addition of magnesium metal as the reductive reagent. Furthermore, it is efficiently available for two monophenylchalcogenide groups generated from diphenyl dichalcogenide. PMID:14750822

Taniguchi, Nobukazu; Onami, Tetsuo

2004-02-01

98

Solid Solution, Mass Transport, and Crystal Growth Studies of Cadmium Iron Selenide.  

NASA Astrophysics Data System (ADS)

Cadmium iron selenide, a semimagnetic semiconductor, has been investigated. Solid solubilities of iron in CdSe were determined at temperatures between 650^ circC and 1100^circC, using the X-ray diffraction Debye-Scherrer powder technique. The solubility limits of Fe in CdSe increase with the temperatures to reach a maximum of about 19.5 mole % FeSe_ {1.24} at 925^circ C, and then decrease with further increasing temperature. Solidification phenomena of the Cd-Fe-Se solid solutions were observed employing optical microscopy, which reveals a typical divorced, eutectic type, nonequilibrium solidification. The combination of the X-ray diffraction and the microscopic investigations yielded a pseudo-binary, eutectic type phase diagram of the Cd-Fe-Se system. Partial pressures of the major vapor species in the Cd-Fe-Se physical and the Cd-Fe-Se-Iodine chemical vapor transport systems were calculated. The partial pressure of gaseous iron species of the PVT system may be neglected compared to those of Cd and Se_2^ecies. This suggests that cadmium iron selenide crystals cannot be grown by the PVT method. For the PVT experiments, using the as-synthesized (CdSe)_ {0.90}(FeSe_{1.24})_{0.10 } source materials, crystals with compositions of 6-8 mole % FeSe_{1.24} were grown at a source temperature of 1000^ circC and a DeltaT of 12^circC. These result are contradictory to the thermodynamic predictions, and were further investigated employing specially purified source materials. Iron contents in the crystals grown in these experiments are close to zero. The transport of iron in the initial mass transport experiments may be due to the chemical impurities (most likely the metal chlorides) in the as-synthesized source materials. Mass transport experiments of the Cd-Fe-Se-Iodine CVT system were performed as a function of source temperatures, the degrees of undercooling (DeltaT), and initial iodine pressures. Promising parameters for the growth of cadmium iron selenide single crystals by the CVT method, e.g., the source temperatures of 800-850 ^circC, initial iodine pressures of 0.5-1.0 atm, and DeltaT of 10 -20^circC, were established. Mass fluxes of cadmium iron selenide were computed using a one -dimensional diffusion equation. The overall trends of the computed mass flux as a function of growth conditions are consistent with the experimental results. However, differences between the theoretical and experimental mass fluxes may be due to the uncertainties of the thermochemical data used and the approximations made in these estimations. Single crystals of cadmium iron selenide with compositions of 6.5-8.5 mole % FeSe_{1.24 } and of about 5 mm edge lengths were successfully grown from the (CdSe)_{0.90 }(FeSe_{1.24})_{0.10} source materials by the CVT method. Compositions of various portions of the bulk crystals are nearly constant along its axis within the error limits, indicating that the crystals possess reasonable compositional uniformity. The indices of the crystal surfaces were obtained by the X -ray diffraction Laue method. The (0001) and (1011) planes usually developed as the natural facets on the surfaces, and (1010) and(1120) as the cleavage planes. A promising chemical etchant for cadmium iron selenide crystals was developed, consisting of about 20 vol. % concentrated HNO_3, 60 vol. % glacial CH _3COOH, and 20 vol. % concentrated H _2SO_4 acids. Etch pit densities of the grown crystals are in the range of 5times10 ^4-rm5times10^5/cm ^2..

Huang, Xuejun

99

COPPER AND BRAIN FUNCTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increasing evidence shows that brain development and function are impaired when the brain is deprived of copper either through dietary copper deficiency or through genetic defects in copper transport. A number of copper-dependent enzymes whose activities are lowered by copper deprivation form the ba...

100

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

Microsoft Academic Search

Good quality thin films of bismuth selenide of thickness up to 0268-1242\\/12\\/5\\/020\\/img7 were deposited from solutions containing bismuth nitrate, triethanolamine and N,N-dimethylselenourea maintained at temperatures ranging from room temperature to 0268-1242\\/12\\/5\\/020\\/img8. X-ray diffraction patterns of the samples annealed at 0268-1242\\/12\\/5\\/020\\/img9 in air match the standard pattern of hexagonal 0268-1242\\/12\\/5\\/020\\/img10 (paraguanajuatite, JCPDS 33-0214). The films exhibit strong optical absorption corresponding to

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

1997-01-01

101

ESR study of the ferrimagnetic spinel selenide CuCr2Se4  

NASA Astrophysics Data System (ADS)

Ferrimagnetic spinel selenide CuCr2Se4 has been investigated by the electron spin resonance (ESR) spectroscopy. Experimental results reveal that ESR signals originate from the localized d-shell electrons of Cr3+ ions. In addition, the ESR linewidth ?HPP increases linearly with decreasing temperature. It is suggested that the spin-orbit coupling may be one of the contributions to the broadening of ?HPP. Our ESR results support the model of the ferrimagnetic hybridization between localized 3d3 electrons of Cr3+ with delocalized holes of Se 4p band.

Zhang, Lei; Tong, Wei; Fan, Jiyu; Zhang, Changjin; Li, Renwen; Zhang, Yuheng

2011-10-01

102

Compositional changes of the first sharp diffraction peak in binary selenide glasses  

NASA Astrophysics Data System (ADS)

Compositional changes of the first sharp diffraction peak (FSDP) in the measured structure factor have been studied for several binary selenide glasses using pulsed-neutron and high-energy x-ray diffraction techniques. The observed variations in the FSDP (factor of 10 in the amplitude and ?0.5Å-1 in the peak position) reflect multiple aspects in the glass network on both the short- and intermediate-range scales and are also correlated with macroscopic properties. An empirical relation has been discovered relating the compositional dependence of the FSDP position to the local coordination number of the guest atom.

Bychkov, E.; Benmore, C. J.; Price, D. L.

2005-11-01

103

Structure and physical properties of gallium selenide laser-intercalated with nickel  

NASA Astrophysics Data System (ADS)

Intercalated crystals of indium and gallium selenide are prepared. It is shown that laser intercalation of nickel into GaSe samples leads to a giant magnetoresistive effect whose magnitude and sign depend on the concentration of the guest component. The giant magnetoresistive effect in the InSe intercalation compounds is considerably weaker and does not exceed 5%. The experimental data obtained are explained in terms of magnetic delocalization (localization) of charge carriers with the participation of states of intercalated magnetically active atoms in the vicinity of the Fermi level.

Pokladok, N. T.; Grygorchak, I. I.; Lukiyanets, B. A.; Popovich, D. I.

2007-04-01

104

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

105

Preparing Copper Powder from Cemented Copper.  

National Technical Information Service (NTIS)

Techniques were developed for preparing metallurgical-grade copper powder from industrially produced cement copper. Flotation was used for rejecting discrete gangue particles, acid leaching to remove residual iron and aluminum, hydrogen reduction to elimi...

J. K. Winter L. G. Evans R. D. Groves

1971-01-01

106

Correlation of the molecular orbitals of organic sulfides (selenides) and five-membered heterocyclic compounds by photoelectron spectroscopy  

Microsoft Academic Search

The structure and the correlation of the molecular orbitals were studied for divinyl chalcogenides and the isoelectronic five-membered heterocyclic compounds by photoelectron spectroscopy (PES). It was shown that the two frontier p orbitals are inverted in the transition from divinyl sulfide to thiophene, while the heterocyclization of divinyl selenide is accompanied by quasidegeneration. According to PES, the orbital structure of

V. K. Turchaninov; L. M. Sinegovskaya; S. V. Eroshchenko; A. F. Ermikov; B. A. Trofimov

1991-01-01

107

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

PubMed Central

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

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

2012-01-01

108

Copper allergy from dental copper amalgam?  

PubMed

A 65-year-old female was investigated due to a gradually increasing greenish colour change of her plastic dental splint, which she used to prevent teeth grinding when sleeping. Furthermore, she had noted a greenish/bluish colour change on the back of her black gloves, which she used to wipe her tears away while walking outdoors. The investigation revealed that the patient had a contact allergy to copper, which is very rare. She had, however, had no occupational exposure to copper. The contact allergy may be caused by long-term exposure of the oral mucosa to copper from copper-rich amalgam fillings, which were frequently used in childhood dentistry up to the 1960s in Sweden. The deposition of a copper-containing coating on the dental splint may be caused by a raised copper intake from drinking water, increasing the copper excretion in saliva, in combination with release of copper due to electrochemical corrosion of dental amalgam. The greenish colour change of the surface of the splint is probably caused by deposition of a mixture of copper compounds, e.g. copper carbonates. Analysis by the X-ray diffraction technique indicates that the dominant component is copper oxide (Cu2O and CuO). The corresponding greenish/bluish discoloration observed on the back of the patient's gloves may be caused by increased copper excretion in tears. PMID:12083714

Gerhardsson, Lars; Björkner, Bert; Karlsteen, Magnus; Schütz, Andrejs

2002-05-01

109

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

NASA Astrophysics Data System (ADS)

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

Aguilar Juarez, Heriberto De Jesus

110

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

NASA Astrophysics Data System (ADS)

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

Little, Scott A.

111

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

NASA Astrophysics Data System (ADS)

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

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

2011-08-01

112

Chemical Bath Deposited Zinc Sulfide Buffer Layers for Copper Indium Gallium Sulfur-selenide Solar Cells and Device Analysis  

SciTech Connect

Cd free CIGSS thin film solar cell structures with a MgF2/TCO/CGD-ZnS/CIGSS/Mo/SLG structure have been fabricated using chemical bath deposited (CBD)-ZnS buffer layers and high quality CIGSS absorber layers supplied from Shell Solar Industries. The use of CBD-ZnS, which is a higher band gap materials than CdS, improved the quantum efficiency of fabricated cells at lower wavelengths, leading to an increase in short circuit current. The best cell to date yielded an active area (0.43 cm2) efficiency of 13.3%. This paper also presents a discussion of the issues relating to the use of the CBD-ZnS buffer materials for improving device performance.

Kundu, Sambhu N.; Olsen, Larry C.

2005-01-03

113

Copper and prion disease  

Microsoft Academic Search

The prion protein is a cell surface glyco-protein expressed by neurones. Its function has remained elusive until it was recently shown to be a copper binding protein. There is now strong evidence that the prion protein has a role in normal brain copper metabolism. Prion protein expression alters copper uptake into cells and enhances copper incorporation into superoxide dismutase. Furthermore

David R Brown

2001-01-01

114

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...

115

[Accumulation of mercuric selenide granules in the liver of Odontocetes (Mammifers, Cetacea): a possible method of detoxification of methylmercury by selenium].  

PubMed

In Mediterranean Cetaceans, concretions of pure mercuric selenide are found in the connective tissue of the liver. Their presence explains that high levels of mercury and selenium coexist with low level of methylmercury. The selenide could be produced parallel with demethylation of mercury, a process leading to the fossilization of mercury and partially of selenium under the form of a non biodegradable component. PMID:409540

Martoja, R; Viale, D

1977-07-01

116

M-lines characterization of selenide and telluride thick films for mid-infrared interferometry  

NASA Astrophysics Data System (ADS)

Nulling interferometry is an astronomical technique that requires to combine extremely flat wavefronts to achieve a deep rejection ratio in order to detect Earth-like planets in the mid-infrared band [5 - 20 µm]. Similarly to what is done in the near-infrared, high spatial filtering of the incoming beams can be achieved using single-mode waveguides operating in the mid-infrared. An appreciable reduction of the instrumental complexity is also possible using integrated optics (IO) devices in this spectral range. The lack of single-mode guided optics in the mid-infrared has motivated the present technological study to demonstrate the feasibility of dielectric waveguides functioning at longer wavelengths. We propose to use selenide and telluride components to pursue the development of more complex IO functions.

Labadie, Lucas; Vigreux-Bercovici, Caroline; Pradel, Annie; Kern, Pierre; Arezki, Brahim; Broquin, Jean-Emmanuel

2006-09-01

117

M-lines characterization of selenide and telluride thick films for mid-infrared interferometry.  

PubMed

Nulling interferometry is an astronomical technique that requires to combine extremely flat wavefronts to achieve a deep rejection ratio in order to detect Earth-like planets in the mid-infrared band [5 - 20 microm]. Similarly to what is done in the near-infrared, high spatial filtering of the incoming beams can be achieved using single-mode waveguides operating in the mid-infrared. An appreciable reduction of the instrumental complexity is also possible using integrated optics (IO) devices in this spectral range. The lack of single-mode guided optics in the mid-infrared has motivated the present technological study to demonstrate the feasibility of dielectric waveguides functioning at longer wavelengths. We propose to use selenide and telluride components to pursue the development of more complex IO functions. PMID:19529223

Labadie, Lucas; Vigreux-Bercovici, Caroline; Pradel, Annie; Kern, Pierre; Arezki, Brahim; Broquin, Jean-Emmanuel

2006-09-01

118

Temperature and carrier-concentration dependences of the thermoelectric properties of bismuth selenide dioxide compounds  

NASA Astrophysics Data System (ADS)

We performed an ab-initio electronic structure calculation for the bismuth selenide compound with oxygen substitution by using the all-electron full-potential linearized augmented plane-wave (FLAPW) method. The spin-orbit coupling in the second variational scheme and the screenedexchange local density approximation (sX-LDA) were adapted, and a large enhancement of the indirect band gap from 0.13 to 0.78 eV over the conventional LDA result was found. Exploiting the FLAPW wave-functions, we employed Boltzmann's equation in a constant relaxation-time approach to estimate the thermoelectric (TE) transport properties, including the Seebeck coefficient, the electrical conductivity and the power factor. The temperature and the carrier-concentration dependences of the TE properties were investigated in detail to find the effect of oxygen substitution on and to search for the optimal doping and temperature range for better thermoelectric performance.

Van Quang, Tran; Lim, Hanjo; Kim, Miyoung

2012-11-01

119

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

NASA Astrophysics Data System (ADS)

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.

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

2011-06-01

120

Functional renormalization group study of pairing symmetry and pairing mechanism in iron-selenide superconductors  

NASA Astrophysics Data System (ADS)

In iron-selenide superconductors, only electronlike Fermi pockets survive, challenging the S± pairing based on the quasinesting between the electron and hole Fermi pockets (as in iron arsenides). We performed a functional renormalization group study and showed that an in-phase S-wave pairing on the electron pockets (See++) is realized. The pairing mechanism involves two competing driving forces: The strong C-type spin fluctuations cause attractive pair scattering between and within electron pockets via Cooperon excitations on the virtual hole pockets, while the G-type spin fluctuations cause repulsive pair scattering. The latter effect is, however, weakened by the hybridization splitting of the electron pockets. The resulting See++-wave pairing symmetry is consistent with experiments. We further propose that the quasiparticle interference pattern in scanning tunneling microscopy and the Andreev reflection in out-of-plane contact tunneling are efficient probes of in-phase versus antiphase S-wave pairing on the electron pockets.

Xiang, Yuan-Yuan; Yang, Yang; Wang, Wan-Sheng; Li, Zheng-Zao; Wang, Qiang-Hua

2013-09-01

121

Photo-induced cooperative covalent-bond switching in amorphous arsenic selenide  

NASA Astrophysics Data System (ADS)

A microstructural mechanism of photoinduced transformations in amorphous arsenic selenide films was studied with IR Fourier-spectroscopy technique in 300-100 cm-1 region. It was shown that stage of irreversible photostructural changes was connected with cooperative process of coordination defect formation accompanied by homopolar chemical bonds switching in heteropolar ones. On the contrary, reversible photoinduced effects were caused by heteropolar chemical bonds switching in homopolar ones, as well as additional channel of bridge heteropolar bonds switching in short-layer ones. The both processes were associated with formation of anomalously coordinated defect pairs and accompanying atomic displacements at the level of medium-range ordering. The developed mathematical simulation procedure testified in a favour of defect-related origin of the reversible photo-thermallyinduced transformations, since their kinetics corresponded to known stretched-exponential dependence, tending to bimolecular behaviour rather then to single-exponential one.

Shpotyuk, O.; Balitska, V.; Filipecki, J.

2005-01-01

122

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

NASA Astrophysics Data System (ADS)

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

Imai, Takashi

2012-02-01

123

Dielectric Properties of Cadmium Selenide (CdSe) Nanoparticles synthesized by solvothermal method  

NASA Astrophysics Data System (ADS)

Synthesis of nanoparticles of cadmium selenide (CdSe) was carried out using solvothermal method with cadmium nitrate and sodium selenite as precursors. Hydrazine hydrate and ethylenediamine tetra acetic acid were used as the capping agent to control the size of the nanoparticles. As their size decreases to their Bohr radius (usually around a few nanometers), all electronic properties change, and equally important, become dependent on size. In this size, a semiconductor nanoparticle transition occurs in which the electrons and holes are confined beyond their natural Bohr radius. The properties become dependent not only on size, but also on shape. The crystalline nature and particle size of the samples were characterized by Powder X-ray diffraction analysis (XRD). The morphology of prepared CdSe nanoparticles was studied by scanning electron microscope. Dielectric studies were carried out for the pelletized sample of CdSe nanoparticles. The ac conductivity of CdSe nanoparticle has been studied. The obtained results are discussed.

Suresh, S.; Arunseshan, C.

2013-01-01

124

Curie temperature and NMR of 53Cr nuclei in doped ferromagnetic cadmium chromium selenide semiconductors  

NASA Astrophysics Data System (ADS)

The effect of alien-valence substitution on exchange interactions in ferromagnetic cadmium chromium selenide spinel is studied both experimentally and theoretically. The Curie temperature is calculated within the molecular field approximation. From comparing the calculated results with experimental dependences of the Curie temperature on impurity concentration and variation in NMR chromium spectra with temperature, a conclusion is drawn in favor of the model of magnetic clusters. The model suggests that, during the alien-valence substitution for nonmagnetic cations, the valence is compensated by a change in the valence state of chromium ions. The excess charge carriers hop between equivalent ions surrounding the impurity. By analogy with the double-exchange model, a detailed description of this hopping and its influence on the exchange interaction of magnetic ions is given.

Kuz'min, E. V.; Polulyakh, S. N.; Berzhansky, V. N.; Abelyashev, G. N.; Aminov, T. G.

2008-10-01

125

Resonance enhancement of nonlinear photoluminescence in gallium selenide and related compounds  

SciTech Connect

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.

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

2012-05-31

126

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

127

Novel chemical synthetic route and characterization of zinc selenide thin films  

NASA Astrophysics Data System (ADS)

Zinc selenide (ZnSe) thin film have been deposited using chemical bath method on non-conducting glass substrate in a tartarate bath containing zinc sulfate, ammonia, hydrazine hydrate, sodium selenosulfate in an aqueous alkaline medium at 333 K. The deposition parameter of the ZnSe thin film is interpreted in the present investigation. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical absorption, electrical measurements, atomic absorption spectroscopy (AAS). The ZnSe thin layers grown with polycrystalline zinc blende system along with some amorphous phase present in ZnSe film. The direct optical band gap ‘Eg’ for the film was found to be 2.81 eV and electrical conductivity in the order of 10-8(? cm)-1 with n-type conduction mechanism.

Hankare, P. P.; Chate, P. A.; Delekar, S. D.; Asabe, M. R.; Mulla, I. S.

2006-11-01

128

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

PubMed

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. PMID:24056899

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

2013-09-26

129

Chalcogenide clusters of copper and silver from silylated chalcogenide sources.  

PubMed

This review summarizes the rich structural variety of copper and silver chalcogenide clusters with protecting ligand shells of phosphane and/or organic ligands that were generated starting out from silylated chalcogenide sources. This route turned out to be fairly selective and thus allows for the isolation of uniform, polynuclear to nanosized cluster molecules that can consist of only a few or up to hundreds of metal atoms, being bridged by the chalcogen atoms. However, all of these clusters are only kinetically stable with respect to the formation of the binary coinage metal chalcogen phases, but do not collapse into the solid M(2)E materials owing to the protection by bulky ligands on the surface. Upon a more detailed analysis of the development of the structural properties with the cluster size, one recognizes differences for the particular M/E combinations: whereas copper chalcogenide and silver selenide clusters show a clear tendency to approach structural patterns of the Cu(2)E bulk, most obvious for the Cu/Se combination, this is not visible for silver sulfide clusters, even not at the largest species with 490 silver and 302 sulfur atoms. Besides the discussion on the structures of title compounds, the review presents insight into the bonding properties, reactivity, thermal and photophysical properties. The latter can be interpreted in terms of the quantum confinement effect, thus demonstrating the clusters to be understood as intermediates between mononuclear complexes and binary bulk phases. PMID:22918377

Fuhr, Olaf; Dehnen, Stefanie; Fenske, Dieter

2012-08-23

130

Vanadium-catalyzed selenide oxidation with in situ [2,3] sigmatropic rearrangement (SOS reaction): scope and asymmetric applications†‡  

PubMed Central

A vanadium-catalyzed method for the oxidation of prochiral aryl, allylic selenides with tandem [2,3] sigmatropic rearrangement has been developed. This protocol has been screened on a series of substrates to test for its generality and effectiveness. The applicability of this methodology to the synthesis of enantiomerically enriched allylic alcohols has been studied on a series of chiral oxazole-containing systems with a diastereomeric ratio (d.r.) of up to 85 : 15. The chiral transfer observed in the allyl alcohol products is the result of a net 1,9- and/or 1,10-induction. Finally, the first example of a selenium–oxygen nonbonding interaction in oxazole-containing selenide appears to have been observed via X-ray crystal analysis.

Campbell Bourland, T.; Yokochi, Alexandre F. T.

2008-01-01

131

A study of the synthesis of bismuth tellurium selenide nanocompounds and procedures for improving their thermoelectric performance  

Microsoft Academic Search

A bismuth tellurium selenide (Bi2TeySe3?y) nanocompound for thermoelectric applications was successfully prepared via a water-based chemical reaction in an atmospheric environment. The compound was less that ca. 100nm in size, with a crystalline structure corresponding to the rhombohedral Bi2Te2.7Se0.3. We sintered the compound via a spark plasma sintering process under the designated sintering conditions and measured the transport properties (i.e.,

Cham Kim; Dong Hwan Kim; Jong Sook Kim; Yoon Soo Han; Jong Shik Chung; Hoyoung Kim

2011-01-01

132

Properties of bismuth selenide intercalated with lithium from a solution of n -C 4 H 9 Li  

Microsoft Academic Search

The lithium-selective intercalation of bismuth selenide (Bi2Se3) samples is accomplished by treating them in a solution of n-butyllithium (n-C4H9Li) in hexane. It is found that, upon incorporation of lithium atoms, the interlayer spacing increases and the resistivity\\u000a in the direction normal to the layers (??) increases by a factor of more than two. The dependence ??(x) acquires the form of

I. I. Grigorchak; V. V. Netyaga; S. V. Gavrilyuk; B. P. Bakhmatyuk; Z. D. Kovalyuk

2001-01-01

133

Fabrication of thin films of bismuth selenide using novel single-source precursors by metal organic chemical vapor deposition  

Microsoft Academic Search

A metal-organic compound, Bi[(SePiPr2)2N]3 has been synthesized and used as a single-source precursor for the deposition of bismuth selenide thin films via low-pressure metal-organic chemical vapor deposition. Crystalline thin films of rhombohedral Bi2Se3 have been deposited on glass substrates. The films have been characterized by X-ray powder diffraction, scanning electron microscopy and energy dispersive analysis of X-rays.

J. Waters; D. Crouch; P. O'Brien; Jin-Ho Park

2003-01-01

134

Electrodeposition and stripping analysis of bismuth selenide thin films using combined electrochemical quartz crystal microgravimetry and stripping voltammetry  

Microsoft Academic Search

Combined stripping voltammetry and electrochemical quartz crystal microgravimetry were employed for the compositional analysis of electrodeposited bismuth selenide (Bi–Se) thin films. Electrodeposited films contain free Bi and free Se in addition to the targeted Bi2Se3 compound and the amount of these “impurity” phases depends on the electrodeposition variables. Thus the free Se content was determined using the reduction peak of

Sunyoung Ham; Soyeon Jeon; Seungun Choi; Ki-Jung Paeng; Noseung Myung; Krishnan Rajeshwar

2010-01-01

135

Analysis of space radiation effects in gallium arsenide and cadmium selenide semiconductor samples using luminescence spectroscopic techniques. Master's thesis  

Microsoft Academic Search

Analysis of space radiation effects in gallium arsenide and cadmium selenide semiconductor samples using luminescence spectroscopic techniques. The M0006 semiconductor samples were placed into a 28.5 degree inclination, 480 km altitude, near-circular orbit aboard the Long Duration Exposure Facility satellite and exposed to direct space environment for a period of 11 months, and were shielded by 0.313 inches of aluminum

Shaffer

1990-01-01

136

Analysis of space radiation effects in gallium arsenide and cadmium selenide semiconductor samples using luminescence spectroscopic techniques  

Microsoft Academic Search

Analysis of space radiation effects in gallium arsenide and cadmium selenide semiconductor samples using luminescence spectroscopic techniques. The M0006 semiconductor samples were placed into a 28.5 degree inclination, 480 km altitude, near-circular orbit aboard the Long Duration Exposure Facility satellite and exposed to direct space environment for a period of 11 months, and were shielded by 0.313 inches of aluminum

Brad L. Shaffer

1990-01-01

137

Copper metabolism of astrocytes  

PubMed Central

This short review will summarize the current knowledge on the uptake, storage, and export of copper ions by astrocytes and will address the potential roles of astrocytes in copper homeostasis in the normal and diseased brain. Astrocytes in culture efficiently accumulate copper by processes that include both the copper transporter Ctr1 and Ctr1-independent mechanisms. Exposure of astrocytes to copper induces an increase in cellular glutathione (GSH) content as well as synthesis of metallothioneins, suggesting that excess of copper is stored as complex with GSH and in metallothioneins. Furthermore, exposure of astrocytes to copper accelerates the release of GSH and glycolytically generated lactate. Astrocytes are able to export copper and express the Menkes protein ATP7A. This protein undergoes reversible, copper-dependent trafficking between the trans-Golgi network and vesicular structures. The ability of astrocytes to efficiently take up, store and export copper suggests that astrocytes play a key role in the supply of neurons with copper and that astrocytes should be considered as target for therapeutic interventions that aim to correct disturbances in brain copper homeostasis.

Dringen, Ralf; Scheiber, Ivo F.; Mercer, Julian F. B.

2013-01-01

138

Copper metabolism of astrocytes.  

PubMed

This short review will summarize the current knowledge on the uptake, storage, and export of copper ions by astrocytes and will address the potential roles of astrocytes in copper homeostasis in the normal and diseased brain. Astrocytes in culture efficiently accumulate copper by processes that include both the copper transporter Ctr1 and Ctr1-independent mechanisms. Exposure of astrocytes to copper induces an increase in cellular glutathione (GSH) content as well as synthesis of metallothioneins, suggesting that excess of copper is stored as complex with GSH and in metallothioneins. Furthermore, exposure of astrocytes to copper accelerates the release of GSH and glycolytically generated lactate. Astrocytes are able to export copper and express the Menkes protein ATP7A. This protein undergoes reversible, copper-dependent trafficking between the trans-Golgi network and vesicular structures. The ability of astrocytes to efficiently take up, store and export copper suggests that astrocytes play a key role in the supply of neurons with copper and that astrocytes should be considered as target for therapeutic interventions that aim to correct disturbances in brain copper homeostasis. PMID:23503037

Dringen, Ralf; Scheiber, Ivo F; Mercer, Julian F B

2013-03-14

139

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

NASA Astrophysics Data System (ADS)

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

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

1997-05-01

140

Analysis of corrosion processes at the surface of diamond-like carbon protected zinc selenide waveguides.  

PubMed

A detailed surface analytical study on the corrosion behavior of unprotected and diamond-like carbon (DLC)-coated mid-infrared (MIR) waveguides used in remote sensing applications at strongly oxidizing conditions is presented. High-quality DLC films, with a thickness of 100 nm serving as MIR-transparent corrosion barrier, have been produced at the surface of zinc selenide (ZnSe) attenuated total reflection waveguides via pulsed laser deposition techniques. IR microscopy and atomic force microscopy are applied to investigate the chemical inertness of DLC-based membranes against aqueous solutions of hydrogen peroxide. These stability studies show that uncoated ZnSe waveguides are subject to severe chemical surface modifications, while DLC-protected waveguides maintain their optical properties and chemical integrity. In situ studies on the corrosion behavior by a recently developed approach combining scanning electrochemical microscopy (SECM) with Au/Hg amalgam ultramicroelectrodes in a scanning stripping voltammetry experiment provides additional insight into the mechanisms of the corrosion process. It is demonstrated that the combination of surface analytical techniques and, in particular, the innovative application of SECM with amalgam electrodes provides superior information on corrosion processes at the surface of optical waveguides. This detailed study confirms the efficiency of protective DLC coatings deposited onto IR-transparent optical waveguides, rendering this novel concept ideal for sensing applications in harsh environments. PMID:15379485

Janotta, Markus; Rudolph, Douglas; Kueng, Angelika; Kranz, Christine; Voraberger, Hannes-Stefan; Waldhauser, Wolfgang; Mizaikoff, Boris

2004-09-28

141

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

PubMed

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

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

142

Patterning of cadmium selenide quantum dot nanocrystals for use with photovoltaic applications  

NASA Astrophysics Data System (ADS)

In this thesis, cadmium selenide (CdSe) quantum dots (QDs) are synthesized and characterized for patterning applications as well as for photovoltaic devices. The QDs were patterned and embedded into various polymers to form fluorescent composites. Their photophysical properties were investigated in detail. Through template assisted deposition the QDs-polymer composites were patterned into fluorescent nanorods. CdSe QDs were combined with multi-wall carbon nanotubes (CNTs) using a synthesized organic perylene derivative dye (N,N'-di(ethanethiol)-perylene-3,4,9,10-tetracarboxyl diimide) (ETPTCDI) as a link between QDs and CNTs. Upon testing, the QDs-ETPTCDI-CNTs nanocomposite displayed photoactive properties. Photophysical quenching studies of QD-ETPTCDI-CNTs provided better understanding of the electron-hole transfer of each component in the nanocomposite. The nanocomposite material was patterned onto microelectrode devices for photocurrent measurements under an AM1.5 solar simulated light source. These nanocomposites can be used as photovoltaic devices. The preliminary characterization studies of the device show excellent photoresponse under AM1.5 solar simulated light. The band gap alignment of each component of the nanocomposite and the charge transfer kinetics are the key to efficient electron-hole transfer. Optimization of the semiconducting material's interface can potentially make these nanocomposites a system for photovoltaic-based devices.

Weaver, Joseph Edison

143

Scaling of the magnetic entropy change in spinel selenide CuCr2Se4  

NASA Astrophysics Data System (ADS)

The magnetic entropy change (?SM) of the spinel selenide CuCr2Se4 has been thoroughly investigated around Curie temperature TC=430K. It is found that the temperature dependence of ?SM under different applied fields H presents a unimodal shape only below 1 T, while the full width at half maximum ?TFWHM becomes broad with the increase of H. We suggest that the suppression of the spin-orbit coupling between Cr3+ 3d electrons and Se 4p states by the external field should be responsible for the suppression of ?SM. In addition, it is displayed that the maximum of ?SM depends on Hn with n=0.63±0.05 obtained by experiment, in agreement with that n=0.62±0.06 deduced by the critical analysis. The relative cooling power [RCP(S)] increases with H fulfilling the relation RCP(S)=aHb, where a=25.4±0.5 J/kg T and b=0.93±0.08. With the scaling laws of ?SM, the experimental ?SM(T,H) collapse onto a universal curve, where an average curve is obtained. With the phenomenological universal curve, the experimental ?SM(T,H) are well predicted.

Zhang, Lei; Fan, Jiyu; Tong, Wei; Ling, Langsheng; Pi, Li; Zhang, Yuheng

2012-09-01

144

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

PubMed

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

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

2012-06-30

145

Chemical processes in the condensation of zinc selenide on gallium arsenide  

SciTech Connect

Heterojunctions of the GaAs-ZnSe type are promising from the standpoint of the possibility of using them as solar energy transformers. In this case, to obtain high efficiency it is necessary to produce structurally perfect heterojunctions. The purpose of this work was to find the optimum conditions of production of epitaxial heterostructures of the GaAs substrate-ZnSe film, structurally perfect and free of oxygen contaminations. Three temperature regions of growth of zinc selenide films on gallium arsenide were found: I) region of physical condensation; II) region of chemical interaction of materials with the formation of an intermediate layer of As/sub 2/Se/sub 3/; III) region of chemical interaction with the formation of an intermediate layer of Ga/sub 2/Se/sub 3/. The dependence of the nature of the chemical interaction on the polarity of the axis <111> of gallium arsenide was detected: The region Ib is absent on the plane )111)Ga, and oriented growth begins at lower temperatures. The values of the activation energies of growth of films in chemical interaction were determined: In the formation of an intermediate layer of As/sub 2/Se/sub 3/, E/sub int/ = 0.7-1 eV; in the formation of Ga/sub 2/Se/sub 3/, E/sub int/ = 2-2.4 eV.

Murav'eva, K.K.; Mirsagator, S.A.; Anorov, N.; Portnova, I.G.

1983-01-20

146

Size-induced effects in gallium selenide electronic structure: The influence of interlayer interactions  

NASA Astrophysics Data System (ADS)

The electronic structure of two-dimensional gallium selenide crystals containing a small number of layers was investigated theoretically and experimentally. The electronic band structure of the layered GaSe crystal was investigated by the first-principles density functional theory calculations. The GW approximation was used for the correction of the band-gap values. A dependence of the band-gap value on the number of tetralayers has been demonstrated. For the thin crystal with several tetralayers, the band gap becomes larger compared to the bulk crystal. The thin layers of GaSe have been experimentally produced by the ultrasonication of GaSe particles in water suspensions in the presence of Pluronic F127 surfactant. Their thickness was from one to a few tetralayers, according to the transmission electron microscopy studies. The optical absorption spectra demonstrate the well-resolved bands, shifted toward the blue relative to those of the bulk GaSe. Their origin is caused by the presence of GaSe structures with one to a few tetralayers.

Rybkovskiy, D. V.; Arutyunyan, N. R.; Orekhov, A. S.; Gromchenko, I. A.; Vorobiev, I. V.; Osadchy, A. V.; Salaev, E. Yu.; Baykara, T. K.; Allakhverdiev, K. R.; Obraztsova, E. D.

2011-08-01

147

Bond thermal expansion and effective pair potential in crystals: the case of cadmium selenide.  

PubMed

The local dynamics of cadmium selenide (CdSe) with wurtzite structure has been investigated by molecular dynamics simulations, using a many-body Tersoff potential. The radial distribution functions (i.e., the effective pair potentials) of the first seven coordination shells have been determined as a function of temperature, as well as their parallel and perpendicular mean-square relative atomic displacements. The bond thermal expansion of the first coordination shell is mainly due to the asymmetry of the effective pair potential. In contrast, the bond thermal expansion of the outer shells is mostly due to a rigid shift of the effective pair potential. This behavior, recently observed also in simple cubic monoatomic crystals, can be generalized and related to the correlation of atomic motion. Finally, a shift toward lower values of the first Se-Cd effective pair potential has been observed when increasing the temperature, confirming previous findings by extended x-ray absorption fine-structure measurements. Differently from superionic conductors like AgI and CuBr, in which this anomalous negative shift was tentatively explained by cluster distortion and cation diffusion, the negative shift of CdSe is related to the peculiar properties of the crystalline potential. PMID:21757799

Sanson, Andrea

2011-07-15

148

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

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

149

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

Microsoft Academic Search

Copper bleed solution generated from an Indian Copper smelter contains high amount of copper and nickel along with several impurities. Attempts have been made to develop a new process for the production of pure copper powder from such streams. The purity of the electrolytic copper powder produced from such bleed streams was found to be 99.93%. Properties such as compact

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

2007-01-01

150

How Bacteria Handle Copper  

Microsoft Academic Search

Copper in biological systems presents a formidable problem: it is essential for life, yet highly\\u000a reactive and a potential source of cell damage. Tight control of copper is thus a cellular necessity.\\u000a To meet this challenge, cells have evolved pumps for transmembranous transport, chaperones for intracellular\\u000a routing, oxidases and reductases to change the oxidation state of copper, and regulators to control gene\\u000a expression

David Magnani; Marc Solioz

151

The roles of zinc selenide sandwiched between organic layers and its applications in white light-emitting diodes  

Microsoft Academic Search

In this paper, the roles of zinc selenide (ZnSe) sandwiched between organic layers, i.e. organic\\/ZnSe\\/aluminum quinoline (Alq3), have been studied by varying device structure. A broad band emission was observed from ITO\\/poly(N-vinylcarbazole)(PVK)(80 nm)\\/ZnSe(120 nm)\\/ Alq3(15 nm)\\/Al under electric fields and it combined the emissions from the bulk of PVK, ZnSe and Alq3, however, emission from only Alq3 was observed from trilayer device ITO\\/N,N?-bis-(1-naphthyl)-N,N?-diphenyl-1,

Shengyi Yang; Yan Jiang; Feng Teng; Zheng Xu; Yanbing Hou; Xurong Xu

2006-01-01

152

First principles study of electronic and mechanical properties of molybdenum selenide type nanowires  

NASA Astrophysics Data System (ADS)

Using the first-principles plane-wave pseudopotential method within density functional theory, we have systematically investigated structural, electronic, and mechanical properties of M2Y6X6 , Y6X6 ( X=Se,Te,S ; Y=Mo,Cr,W ; and M=Li,Na ) nanowires and bulk phase of M2Y6X6 . We found that not only Mo6X6 , but also transition metal and chalcogen atoms lying in the same columns of Mo and Se can form stable nanowires consisting of staggered triangles of Y3X3 . We have shown that all wires have nonmagnetic ground states in their equilibrium geometry. Furthermore, these structures can be either a metal or semiconductor depending on the type of chalcogen element. All Y6X6 wires with X=Te atom are semiconductors. Mechanical stability, elastic stiffness constants, breaking point, and breaking force of these wires have been calculated in order to investigate the strength of these wires. Ab initio molecular dynamic simulations performed at 500K suggest that overall structure remains unchanged at high temperature. Adsorption of H, O, and transition metal atoms like Cr and Ti on Mo6Se6 have been investigated for possible functionalization. All these elements interact with Mo6Se6 wire forming strong chemisorption bonds, and a permanent magnetic moment is induced upon the adsorption of Cr or Ti atoms. Molybdenum selenide-type nanowires can be alternative for carbon nanotubes, since the crystalline ropes consisting of one type of (M2)Y6X6 structures can be decomposed into individual nanowires by using solvents, and an individual nanowire by itself is either a metal or semiconductor and can be functionalized.

Çak?r, D.; Durgun, E.; Gülseren, O.; Ciraci, S.

2006-12-01

153

Ultrafast exciton dynamics in cadmium selenide nanocrystals determined by femtosecond fluorescence upconversion spectroscopy  

NASA Astrophysics Data System (ADS)

Femtosecond fluorescence upconversion spectroscopy is a technique that allows the unambiguous determination of the excited state dynamics of an analyte. Combining this method with the use of tunable laser excitation, the exciton dynamics in semiconducting nanocrystals (NC's) of cadmium selenide (CdSe) have been determined, devoid of the complications arising from more common spectroscopic methods such as pump-probe. The results of this investigation were used to construct a model to fully describe the three-level system comprising of the valence and conduction bands and surface states, which have been calculated by others to lie mid-gap in energy. Smaller NC's showed faster decay components due to increased interaction between the exciton and surface states. The deep trap emission, which has never before been measured by ultrafast fluorescence techniques, shows a rapid rise time (˜2 ps), which is attributed to surface selenium dangling bonds relaxing to the valence band and radiatively combining with the photo-generated hole. The band edge fluorescence decays as the deep trap emission grows in, inherently coupling the two processes. An experiment which measured the dependence of the excitation energy showed that increased energy imparted to the NC's resulted in increased rise times, yielding the timescales for exciton relaxation through the valence and conduction band states to the lowest emitting state. Surface-oxidized and normally-passivated NC's display the same decay dynamics in time but differ in relative amplitude; the latter point agrees with steady-state measurements. The rotational anisotrophy of the NC's was measured and agrees with previous pump-probe data. Upconversion on the red and blue sides of the static fluorescence spectrum showed no discernable differences, which is either and inherent limitation of the experimental apparatus, or the possibility that lower-lying triplet states are populated on a timescale below the instrument resolution.

Underwood, David Frederick

154

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

NASA Astrophysics Data System (ADS)

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.

Lee, Nicholas Jabari Ouma

155

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...

156

Corrosion of Copper Pipes  

Microsoft Academic Search

Rapid pitting of the walls of copper pipes used in plumbing has resulted in several controversial overtones. The results of a study of the problem in southern California are now available in this article and should benefit the water purveyor, who is, after all, responsible for taking reasonable measures to prevent unnecessary corrosion to copper service lines

Henry Cruse; Richard D. Pomeroy

1974-01-01

157

Oxidation resistant copper  

NASA Astrophysics Data System (ADS)

Oxidation resistant particles composed of copper and at least one metal having a valence of +2 or +3 and having an intermediate lattice energy for the metal in its hydroxide form are presented. The metal is selected from nickel, cobalt, iron, manganese, cadmium, zinc, tin, magnesium, calcium and chromium. In one embodiment, the phases of copper and at least one metal in the particles are separate and the concentration of the metal is greater near the surface of the particles than inwardly thereof. Process for making the oxidation resistant copper particles includes the steps of dissolving a copper salt and a salt of at least one of the metals in a suitable solvent or diluent; forming primary particles of copper and at least one metal in basic form by mixing a base and the salt solution; separating, washing and drying the primary particles; reducing the primary particles to metallic form; and heat treating the particles in metallic form at an elevated temperature.

Edelstein, Alan S.; Kaatz, Forrest H.; Harris, Vincent G.

1993-11-01

158

Reduction of selenate to selenide by sulfate-respiring bacteria: experiments with cell suspensions and estuarine sediments. [Desulfovibrio desulfuricans  

SciTech Connect

Washed cell suspensions of Desulfovibrio desulfuricans subsp. aestuarii were capable of reducing nanomolar levels of (/sup 75/Se)selenate to (/sup 75/Se)selenide as well as sulfate to sulfide. Reduction of these species was inhibited by 1 mM selenate or tungstate. The addition of 1 mM sulfate decreased the reduction of selenate and enhanced the reduction of sulfate. Increasing concentrations of sulfate inhibited rates of selenate reduction but enhanced sulfate reduction rates. Cell suspensions kept in 1 mM selenate were incapable of reducing either selenate or sulfate when the selenate/sulfate ratio was greater than or equal to0.02, indicating that irreversible inhibition occurs at high selenate concentrations. Anoxic estuarine sediments having an active flora of sulfate-respiring bacteria were capable of a small amount of selenate reduction when ambient sulfate concentrations were low (<4 mM). These results indicate that sulfate is an inhibitor of the reduction of trace quantities of selenate. Therefore, direct reduction of traces of selenate to selenide by sulfate-respiring bacteria in natural environments is constrained by the ambient concentration of sulfate ions. The significance of this observation with regard to the role sediments play in sequestering selenium is discussed.

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

1987-06-01

159

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

USGS Publications Warehouse

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

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

1987-01-01

160

Techniques of copper recovery from Mexican copper oxide ore  

Microsoft Academic Search

Mexican copper ore is a mixed ore containing mainly copper oxide and some copper sulfide that responds well to flotation. The joint techniques of flotation and leaching were studied. The results indicate that an ore containing 19.01% copper could be obtained at a recovery ratio of 35.02% by using sodium sulfide and butyl xanthate flotation. Over 83.33% of the copper

Zhan-fang CAO; Hong ZHONG; Guang-yi LIU; Shu-juan ZHAO

2009-01-01

161

Copper sensitivity of Gonyaulax tamarensis  

Microsoft Academic Search

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

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

1978-01-01

162

Copper accumulation by cultured astrocytes.  

PubMed

To study copper transport in brain astrocytes, we have used astrocyte-rich primary cultures as model system. Cells in these cultures contained a basal copper content of 1.1+/-0.4 nmol per mg protein. The cellular copper content increased strongly after application of copper chloride in a time and concentration-dependent manner. Analysis of the linear copper accumulation during the first 5 min of copper exposure revealed that cultured astrocytes accumulated copper with saturable kinetics with apparent K(M)- and V(max)-values of 9.4+/-1.8 microM and 0.76+/-0.13 nmol/(min x mg protein), respectively. In contrast, incubation of astrocytes with copper in the presence of ascorbate caused a linear increase of the copper accumulation rates for copper concentrations of up to 30 microM. In addition, copper accumulation was strongly inhibited by the presence of an excess of zinc or of various other divalent metal ions. The presence of mRNA and of immunoreactivity of the copper transport protein Ctr1 in astrocyte cultures suggests that Ctr1 contributes to the observed copper accumulation. However, since some characteristics of the observed copper accumulation are not consistent with Ctr1-mediated copper transport, additional Ctr1-independent mechanism(s) are likely to be involved in astrocytic copper accumulation. PMID:20004225

Scheiber, Ivo F; Mercer, Julian F B; Dringen, Ralf

2009-12-11

163

COPPER CABLE RECYCLING TECHNOLOGY  

SciTech Connect

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.

Chelsea Hubbard

2001-05-01

164

Structural Characteristics of Zinc Selenide Based Heterostructures Grown on Gallium Arsenide Substrates by Molecular Beam Epitaxy  

NASA Astrophysics Data System (ADS)

Zinc selenide and its family of II-VI alloys possess direct wide bandgaps that make them candidates for short wavelength solid state lasers with emission ranging from the green to ultra violet. Until recent advances in growth techniques, p-type doping in ZnSe had not been achieved. With the advent of p-type material came the possibility of producing LEDs and lasers. The operation, efficiency and lifetime of such devices not only depends on the electrical properties of the layers but can be influenced significantly by the structural characteristics as well. It is the purpose of this work to characterize the microstructure of these ZnSe based heterostructures in order to find the optimum growth conditions for reducing the defect density in the layers. The growths of the layers were performed by molecular beam epitaxy using GaAs wafers as the substrate material. The structural characterization was performed by a combination of transmission electron microscopy and X-ray diffraction techniques. The growth of ZnSe on GaAs is accompanied by a lattice mismatch (difference in equilibrium lattice constants). When the layer reaches a thickness of ~1500A (critical layer thickness) misfit dislocations nucleate from the surface of the layer and glide to the interface to relax the lattice misfit strain. Because of the relaxation by misfit dislocations the layers always contain densities of threading dislocations with a range of 10^6cm^{ -2} to 10^8cm ^{-2} depending on growth conditions. The only way to produce ZnSe layers with lower densities is to stop the growth before critical layer thickness is reached. An alternative is to match the lattice constant of GaAs by alloying S and Mg with ZnSe in the proper ratios. Separate confinement heterostructures (confinement of the free carriers and optical field is in different layers) have been produced with these alloys with dislocation densities < 4 times 10^4 cm^{-2}. The devices made from these high structural quality wafers have given the best device performance parameters to date. Although significant advances have been made there is still a need for improvement in the structural as well as other properties in these materials.

Petruzzello, John

165

A surface and interface study of aluminum selenide on silicon: Growth and characterization of thin films  

NASA Astrophysics Data System (ADS)

The first growth of aluminum selenide on silicon is reported. A thin AlSe layer was formed on Si(111) by molecular beam epitaxy from a stoichiometric Al2Se3 evaporative source. The structural and electronic properties of the interface were investigated using angle-resolved valence and core-level photoelectron spectroscopy and diffraction. The AlSe-Si interface forms a bilayer structure similar to GaSe-terminated Si, however, the temperatures for bilayer formation and for Se re-evaporation from the film are higher for AlSe than for GaSe. In addition, the valence band structure shows that the AlSe bilayer termination electronically passivates the bulk Si with all interface states within the bulk Si bands. The passivated nature of the AlSe-terminated Si(11) surface make this a good candidate substrate for growth of quantum dots or other heteroepitaxy. To test their chemical stability, AlSe-terminated Si(111) and GaSe-terminated Si(111) have been exposed to a variety of atmospheric constituents. The resulting surfaces were investigated by photoelectron spectroscopy to examine changes, if any, in the local chemical environment of atomic constituents. The GaSe-terminated Si substrates were largely unaffected by the exposures, and physisorbed contaminants were easily removed by mild annealing. AlSe-terminated Si reacted with both pure O2 and atmosphere, and the clean bilayer surface was not recoverable. The differences in chemical stability show that GaSe would be more suitable than AlSe as a substrate for further heteroepitaxy (e.g. quantum dot formation) under a wide range of growth conditions; despite having lower temperature stability. We have also produced epitaxial thin films of Al2Se3 on Si(111). Higher flux rates of Al2Se3 are necessary to grow Al2Se3 bulk films on silicon than to form the interface bilayer. Photoemission spectroscopy was used to examine films of graded thickness, and the evolution of chemical environment and electronic structure with increasing film thickness was observed. Intermediate-thickness film characteristics are compared to those of the bilayer interface and of bulk Al2Se3. Also, we have measured the valence electronic structure of "thick" thin films of Al2Se3 grown on Si(111). With increasing thickness above the interface bilayer, the thin films show rapid development of bulk-like features, including the 3x3 vacancy ordering.

Adams, Jonathan A.

166

Canine models of copper toxicosis for understanding mammalian copper metabolism.  

PubMed

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

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

2011-12-07

167

Copper Containing Ballistic Additives.  

National Technical Information Service (NTIS)

In accordance with this invention, it has been found that the addition of certain copper compounds to solid propellant composition can materially increase the burning rate of the propellant grains while simultaneously reducing the pressure exponent in the...

R. C. Corley

1981-01-01

168

Electrodeposition of Copper.  

National Technical Information Service (NTIS)

The patent application consists of a method for electrowinning or electrorefining of metals, particularly copper, comprising electro-depositing the metal from an electrolyte solution under conditions comprising high cathode and anode current densities and...

Schlain McCawley Smith

1976-01-01

169

Stabilized Electroless Copper Solution.  

National Technical Information Service (NTIS)

The electroless copper plating solution contains Fehling's solution, a reducing agent such as formaldehyde and a stabilizing amount of 2-mercapto-benzothiazole. The solution is more stable than prior solutions.

F. Pearlstein

1965-01-01

170

Entrainment behavior of copper and copper matte in copper smelting operations  

Microsoft Academic Search

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

S. W. Ip; J. M. Toguri

1992-01-01

171

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

SciTech Connect

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.

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

1992-06-01

172

Copper deficiency myelopathy  

Microsoft Academic Search

Acquired copper deficiency has been recognised as a rare cause of anaemia and neutropenia for over half a century. Copper\\u000a deficiency myelopathy (CDM) was only described within the last decade, and represents a treatable cause of non-compressive\\u000a myelopathy which closely mimics subacute combined degeneration due to vitamin B12 deficiency. Here, 55 case reports from the\\u000a literature are reviewed regarding their

Stephan R. JaiserGavin; Gavin P. Winston

2010-01-01

173

Copper and Copper Alloy Powders. Seminar Held on 18th December 1976.  

National Technical Information Service (NTIS)

This report contains the following papers: Types, Properties and Uses of Copper Powder; Production of Copper & Copper Alloy Powders for General Engineering Applications; Bronze Powders; Atomized Copper and Copper Based Powders; Process and Equipment for t...

1976-01-01

174

Localization of copper and copper transporters in the human brain.  

PubMed

Disturbances in brain copper result in rare and severe neurological disorders and may play a role in the pathogenesis and progression of multiple neurodegenerative diseases. Our current understanding of mammalian brain copper transport is based on model systems outside the central nervous system and no data are available regarding copper transport systems in the human brain. To address this deficit, we quantified regional copper concentrations and examined the distribution and cellular localization of the copper transport proteins Copper transporter 1, Atox1, ATP7A, and ATP7B in multiple regions of the human brain using inductively coupled plasma-mass spectrometry, Western blot and immunohistochemistry. We identified significant relationships between copper transporter levels and brain copper concentrations, supporting a role for these proteins in copper transport in the human brain. Interestingly, the substantia nigra contained twice as much copper than that in other brain regions, suggesting an important role for copper in this brain region. Furthermore, ATP7A levels were significantly greater in the cerebellum, compared with other brain regions, supporting an important role for ATP7A in cerebellar neuronal health. This study provides novel data regarding copper regulation in the human brain, critical to understand the mechanisms by which brain copper levels can be altered, leading to neurological disease. PMID:23076575

Davies, Katherine M; Hare, Dominic J; Cottam, Veronica; Chen, Nicholas; Hilgers, Leon; Halliday, Glenda; Mercer, Julian F B; Double, Kay L

2013-01-01

175

Synthesis and characterization of hexagonal nano-sized nickel selenide by simple hydrothermal method assisted by CTAB  

NASA Astrophysics Data System (ADS)

Nano-sized nickel selenide powders have been successfully synthesized via an improved hydrothermal route based on the reaction between NiCl 2·6H 2O, SeCl 4 and hydrazine (N 2H 4·H 2O) in water, in present of cetyltrimethyl ammonium bromide (CTAB) as surfactant, at various conditions. The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray energy dispersive spectroscopy analysis. Effects of temperature, reaction time and reductant agent on the morphology, the particle sizes and the phase of the final products have been investigated. It was found that the phase and morphology of the products could be greatly influenced by these parameters. The synthesis procedure is simple and uses less toxic reagents than the previously reported methods. Photoluminescence (PL) was used to study the optical properties of NiSe samples.

Sobhani, Azam; Davar, Fatemeh; Salavati-Niasari, Masoud

2011-07-01

176

An approach to global rovibrational analysis based on anharmonic ladder operators: Application to hydrogen selenide and hydrogen sulfide  

NASA Astrophysics Data System (ADS)

A formalism to model the ro-vibrational spectrum of triatomic asymmetric top molecules is presented. The quantum mechanical ro-vibrational kinetic and potential energy function is considered as a Taylor expansion in internal coordinates of Morse local oscillators. Thereafter, local Morse coordinates and momenta are expanded in terms of Morse Potential ladder operators. Only polyad-conserving terms are considered. Expansions of the kinetic and potential energies of the ro-vibrational Hamiltonian are considered up to sextic terms. The resulting Hamiltonian was diagonalized using a symmetry-adapted basis, generated by the eigenfunction method ( J.Q.Chen, Group Representation Theory for Physicists,World Scientific, 1989; R. Lemus, 2003 Mol.Phys., 101 2511-2528.). The model is applied to hydrogen sulfide (H_2S) and hydrogen selenide (H_2Se).

Perez-Bernal, F.; Carvajal, M.; Alvarez-Bajo, O.

2011-05-01

177

Copper deficiency in celiac disease.  

PubMed

Copper deficiency is an uncommonly reported complication of celiac disease that has not received much attention in recent years. Copper deficiency may result in anemia and thrombocytopenia and also irreversible myeloneuropathy if it is not detected and treated appropriately. The prevalence of copper deficiency in patients with celiac disease is unknown. We describe 5 patients with celiac disease and associated copper deficiency diagnosed at our institution in recent years. All 5 patients had neurologic complications of copper deficiency and 3 patients also presented with hematologic abnormalities. We also review the literature regarding copper deficiency in celiac disease. PMID:18496230

Halfdanarson, Thorvardur R; Kumar, Neeraj; Hogan, William J; Murray, Joseph A

2009-02-01

178

Electrowinning of Copper from Chloride Solutions.  

National Technical Information Service (NTIS)

Electrowinning of copper from chloride solutions was studied in a diaphragm cell. The copper powder product was shaken periodically from the cathode and removed from the bottom of the cell. The effects of copper concentration, brine concentration, copper ...

R. E. Mussler R. S. Olsen T. T. Campbell

1975-01-01

179

Bacterial Killing by Dry Metallic Copper Surfaces?  

PubMed Central

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.

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

2011-01-01

180

Physical and Mechanical Properties of Copper and Copper Alloys  

SciTech Connect

High strength, high conductivity copper alloys are prime candidates for high heat flux applications in fusion energy systems. This chapter reviews the physical and mechanical properties of pure copper and copper alloys with the focus on precipitation-hardened CuCrZr and dispersion-strengthened CuAl25 alloys. The effect of neutron irradiation on copper and copper alloys is reviewed in terms of radiation effects on physical properties and mechanical properties (tensile properties, fracture toughness, fatigue and creep-fatigue), irradiation creep and void swelling. The effect of irradiation on the microstructure of copper and copper alloys and dislocation channeling is also presented. Joining techniques for copper alloys in fusion plasma facing components are briefly discussed.

Li, Meimei [Argonne National Laboratory (ANL); Zinkle, Steven J [ORNL

2012-01-01

181

Copper Proteins and Oxygen  

PubMed Central

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.

Frieden, Earl; Osaki, Shigemasa; Kobayashi, Hiroshi

1965-01-01

182

Copper and copper-nickel alloys as zebra mussel antifoulants  

SciTech Connect

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.

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

1996-04-01

183

Copper alloys for industrial hardware  

SciTech Connect

Copper and its alloys are widely used because of their excellent electrical and thermal conductivities, outstanding resistance to corrosion, and ease of fabrication. Lifecycle costs are another important reason for new and expanding applications for copper and copper alloys. For example, lifecycle cost analyses favor the use of copper-nickel for automotive brake tubes, and copper alloys in molds for plastic parts. However, copper also competes very well on a first-cost basis in the brazed copper-and-brass radiator, and in free-cutting brass machined components. This article highlights four specific applications in which advanced copper alloys and fabrication techniques enhance the performance of industrial hardware, based largely on conductivity, corrosion resistance, and lifecycle costs.

Peters, D.T. [Copper Development Association Inc., New York, NY (United States)

1996-10-01

184

Strong participation of selenium substituents in decomposition of pyrazolines formed by 1,3-dipolar cycloaddition of appropriate vinyl selenides with diazoalkanes  

SciTech Connect

Decomposition of 4-(arylseleno)pyrazolines (3) bearing two electron-withdrawing groups such as COOMe, COMe, and CN at C-3, which were prepared in situ by reaction of the corresponding aryl vinyl selenides (2) with diazoalkanes, are reported. The pyrazolines decompose below 0{degree}C to give allyl aryl selenide derivatives (4) by migration of 4-arylseleno group to C-5 concerted with extrusion of nitrogen. Facile decomposition of the pyrazolines with migration of the selenium substituent is explained by strong contribution of intramolecular diazonium salt resonance structure, within which arylseleno groups strongly participate in the decomposition. Most reactions of 2 with 2 mol of diazoalkanes gave the pyrazolines 5, whereas reaction of 2c with 2 mol of 2-diazopropane gave a reverse orientation adduct, the pyrazoline 9.

Hamaguchi, Masashi; Nagai, Toshikazu (Osaka Univ. (Japan))

1989-08-04

185

SOURCES OF COPPER AIR EMISSIONS  

EPA Science Inventory

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

186

Multilevel Dual Damascene copper interconnections  

Microsoft Academic Search

Copper has been acknowledged as the interconnect material for future generations of ICs to overcome the bottlenecks on speed and reliability present with the current Al based wiring. A new set of challenges brought to the forefront when copper replaces aluminum, have to be met and resolved to make it a viable option. Unit step processes related to copper technology

S. Lakshminarayanan

1997-01-01

187

Evidence for the involvement of the serotonergic 5-HT2A/C and 5-HT3 receptors in the antidepressant-like effect caused by oral administration of bis selenide in mice.  

PubMed

The present study investigated a possible antidepressant-like activity of bis selenide using two predictive tests for antidepressant effect on rodents: the forced swimming test (FST) and the tail suspension test (TST). Bis selenide (0.5-5 mg/kg, p.o.) decreased the immobility time in the mouse FST and TST. The anti-immobility effect of bis selenide (1 mg/kg, p.o.) in the TST was prevented by the pretreatment of mice with p-chlorophenylalanine methyl ester (PCPA; 100 mg/kg, i.p., an inhibitor of serotonin synthesis), ketanserin (1 mg/kg, i.p., a 5-HT(2A/2C) receptor antagonist), and ondasentron (1 mg/kg, i.p., a 5-HT(3) receptor antagonist). Pretreatment of mice with prazosin (1 mg/kg, i.p., an alpha(1)-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an alpha(2)-adrenoceptor antagonist), propranolol (2 mg/kg, i.p., a beta-adrenoceptor antagonist), SCH23390 (0.05 mg/kg, s.c., a dopamine D(1) receptor antagonist), sulpiride (50 mg/kg, i.p., a dopamine D(2) receptor antagonist), or WAY 100635 (0.1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist) did not block the antidepressant-like effect of bis selenide (1 mg/kg, p.o.) in the TST. Administration of bis selenide (0.1 mg/kg, p.o.) and fluoxetine (1 mg/kg), at subeffective doses, produced an antidepressant-like effect in the TST. Bis selenide did not alter Na(+) K(+) ATPase, MAO-A and MAO-B activities in whole brains of mice. Bis selenide produced an antidepressant-like effect in the mouse TST and FST, which may be related to the serotonergic system (5-HT(2A/2C) and 5-HT(3) receptors). PMID:19961893

Jesse, Cristiano R; Wilhelm, Ethel A; Bortolatto, Cristiani F; Nogueira, Cristina W

2009-12-02

188

Copper leaching from chalcopyrite concentrates  

NASA Astrophysics Data System (ADS)

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.

Wang, Shijie

2005-07-01

189

Copper Compounds in Plants.  

National Technical Information Service (NTIS)

A study of the distribution of copper compounds in leaves and in isolated chloroplasts of Primula obconica and Trifolium repens shows that a considerable content of them has been found in the fraction of substances soluble in chloroform and ether. The hig...

S. G. Yuferova G. N. Saenko E. A. Boichenko

1969-01-01

190

Hohenheim Consensus Workshop: Copper  

Microsoft Academic Search

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

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

2002-01-01

191

Type Zero Copper Proteins  

PubMed Central

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.

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

2009-01-01

192

Creative Copper Crests  

ERIC Educational Resources Information Center

|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…

Knab, Thomas

2011-01-01

193

Presenilin Promotes Dietary Copper Uptake  

PubMed Central

Dietary copper is essential for multicellular organisms. Copper is redox active and required as a cofactor for enzymes such as the antioxidant Superoxide Dismutase 1 (SOD1). Copper dyshomeostasis has been implicated in Alzheimer’s disease. Mutations in the presenilin genes encoding PS1 and PS2 are major causes of early-onset familial Alzheimer’s disease. PS1 and PS2 are required for efficient copper uptake in mammalian systems. Here we demonstrate a conserved role for presenilin in dietary copper uptake in the fly Drosophila melanogaster. Ubiquitous RNA interference-mediated knockdown of the single Drosophila presenilin (PSN) gene is lethal. However, PSN knockdown in the midgut produces viable flies. These flies have reduced copper levels and are more tolerant to excess dietary copper. Expression of a copper-responsive EYFP construct was also lower in the midgut of these larvae, indicative of reduced dietary copper uptake. SOD activity was reduced by midgut PSN knockdown, and these flies were sensitive to the superoxide-inducing chemical paraquat. These data support presenilin being needed for dietary copper uptake in the gut and so impacting on SOD activity and tolerance to oxidative stress. These results are consistent with previous studies of mammalian presenilins, supporting a conserved role for these proteins in mediating copper uptake.

Southon, Adam; Greenough, Mark A.; Ganio, George; Bush, Ashley I.; Burke, Richard; Camakaris, James

2013-01-01

194

Copper--a rare sensitizer.  

PubMed

To determine the incidence of patch test reactions to copper, 2% copper sulphate was included in our routine patch test series. The allergic potential of copper sulphate was evaluated by the guinea pig maximization test method (GPMT). 13 of the 1190 eczema patients showed reactions (1.1%), but they were considered non-relevant. 3 series of GPMT demonstrated that copper sulphate was a grade I allergen. A critical review of the literature disclosed that several reports on cases of allergic contact dermatitis to copper must be regarded as uncertain or non-relevant. 4 cases were considered relevant and another 20 cases probably relevant. It is suggested that a test reaction to copper sulphate should be verified by a serial dilution test (SDT). Furthermore, the sensitivity of patients to other metals should be stated, so that one can be aware that false positive reactions from metal impurities, especially nickel, in the copper salt used for testing may occur. PMID:6851521

Karlberg, A T; Boman, A; Wahlberg, J E

1983-03-01

195

Low temperature scanning tunneling spectroscopy of proximity effect junctions formed on the layered superconductors niobium selenide and bismuth strontium calcium copper oxide  

NASA Astrophysics Data System (ADS)

Since the advent of the scanning tunneling microscope in 1981, a large number of techniques have been developed using the STM to perform high resolution electronic spectroscopy. The unique ability of the STM to perform atomic resolution imaging combined with the capacity to probe the local energy dependent density of electronic states makes scanning tunneling microscopy and spectroscopy (STM/STS) exceptional tools for the investigation of the properties of materials on the microscopic and mesoscopic length scales. The ongoing development of STM systems has brought instruments which work under ultra-high vacuum and at very low temperatures (T < 200mK) which are capable of measuring the local properties of many superconducting materials. Such phenomena as vortex lattice structure, the increased density of states inside a vortex core and tunneling spectroscopy of high Tc superconductors have been measured with such an instrument. This work represents the application of STM/STS techniques to very thin normal metal layers placed in good electrical contact with superconducting substrate materials. Of particular interest is the nature of the superconductor-normal metal interface and the proximity effect modifications to the local density of states. When the contact between a normal and superconducting material is sufficiently good, superconducting pairs of electrons can leak into the normal metal and induce some of the properties of superconductivity near the NS interface. This proximity effect is of critical importance to some of the superconducting device technologies which have been proposed, especially those involving the short coherence length high Tc superconductors. There is considerable debate over the mechanism and nature of superconductivity in the high Tc cuprates and whether the order parameter has simple S-wave or some more complicated symmetry and little is known about the proximity effect between these compounds and conventional metals. Measurements of the proximity modified density of states at the surface of thin normal metal layers placed on the clean surface of NbSe2 and Bi2Sr2Ca1CU2O8 superconductors will be presented. The results on NbSe2 will be interpreted in terms of quasiparticle bound states below the energy gap of the superconductor which have an energy dependence on the normal metal thickness. A series of results will be presented with a consistent method of interpretation. The results for normal metal layers on the high Tc superconductor Bi 2Sr2Ca1CU2O8 indicate a proximity induced energy gap in the density of states for the normal metal layer. However, this shape of the resulting conductance spectra are significantly different than for a conventional proximity effect system. A series of measurements will be presented along with some possible ideas for future experiments.

Truscott, Anthony D.

196

Production of ultrahigh purity copper using waste copper nitrate solution.  

PubMed

The production of ultrahigh purity copper (99.9999%) by electrolysis in the presence of a cementation barrier has been attempted employing a waste nitric copper etching solution as the electrolyte. The amount of copper deposited on the cathode increased almost linearly with electrolysis time and the purity of copper was observed to increase as the electrolyte concentration was increased. At some point, however, as the electrolyte concentration increased, the purity of copper decreased slightly. As the total surface area of cementation barrier increased, the purity of product increased. The electrolyte temperature should be maintained below 35 degrees C in the range of investigated electrolysis conditions to obtain the ultrahigh purity copper. Considering that several industrial waste solutions contain valuable metallic components the result of present study may support a claim that electrowinning is a very desirable process for their treatment and recovery. PMID:12719148

Choi, J Y; Kim, D S

2003-04-25

197

Additive monitoring and interactions during copper electroprocessing  

Microsoft Academic Search

The electrochemical deposition of copper has been a major focus of research for decades. Renewed interest in copper electroplating is not limited to the copper producers but is also a major concern of semiconductor manufacturers. The focus on copper electrochemistry by the semiconductor manufacturers has increased since IBM's announcement in 1997 that copper will be used for metallization in high

Dale Wade Collins

2001-01-01

198

Friction stir welding of copper and copper alloys  

Microsoft Academic Search

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

K. Nakata

2005-01-01

199

Catecholase Activity Associated with Copper-S100B †  

Microsoft Academic Search

This study addresses the spectroscopic properties and reactivity associated with the copper- loaded form of S100B isolated from bovine brain. Copper(II)-S100B displays EPR features typical of a type II copper center and is shown here to exhibit catecholase activity, the two-electron oxidation of catechols. The steady-state kinetics associated with the oxidation of several catecholamines has been probed in order to

SueAnn Z. Senior; Laura L. Mans; Heather D. VanGuilder; Kimberly A. Kelly; Michael P. Hendrich; Timothy E. Elgren

2003-01-01

200

Copper Chaperones, Intracellular Copper Trafficking Proteins. Function, Structure, and Mechanism of Action  

Microsoft Academic Search

This review summarizes findings on a new family of small cytoplasmic proteins called copper chaperones. The copper chaperones bind and deliver copper ions to intracellular compartments and insert the copper into the active sites of specific partners, copper-dependent enzymes. Three types of copper chaperones have been found in eukaryotes. Their three-dimensional structures have been determined, intracellular target proteins identified, and

K. A. Markossian; B. I. Kurganov

2003-01-01

201

Copper losses and thermodynamic considerations in copper smelting  

Microsoft Academic Search

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

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

1997-01-01

202

Selecting copper and copper alloys; Part 1: Wrought products  

SciTech Connect

Coppers and copper alloys comprise one of the largest families of engineering materials. In North America alone, there are currently more than 275 recognized standard wrought grades, which can make the task of selecting the proper one for a new product appear bewildering. Best known for high conductivity and corrosion resistance, this large and diverse family of materials also offers a wide range of mechanical and physical properties, often in unique combinations. This article is intended to acquaint engineers with wrought coppers and copper alloys, and thereby help guide the selection process.

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

1994-02-01

203

Copper loss from the copper T model TCu22OC.  

PubMed

The effect of mineral deposits on the copper dissolution rate of the Copper T Model TCu22OC was examined. 118 Copper T22OC devices removed from subjects for various medical and personal reasons after 12 to 72 months in utero were examined and graded based on the proportion of the total copper area covered with mineral deposits. The deposits increased in average size during the first three years of IUD use and then remained relatively constant. Seventeen percent of the devices were in situ for four or more years. Copper analysis was performed on 30 Copper T 22OC devices from selected periods of use : 12-14, 22-26, 36-39 and 48-72 months of use. The mean daily copper loss was 29.4 micrograms and the range, 7.3 to 62.1 micrograms. An inverse correlation between the amount of mineral deposit on the copper surface and the rate of copper loss was observed. PMID:7172675

Thiery, M; Schmidt, F; Tatum, H J

1982-09-01

204

[Determination of gold in copper matte and sintered copper material].  

PubMed

Ore sample, pretreated at 650 degrees C, was decomposed with aqua regia. Gold in the sample solution was then pre-concentrated by adsorbing with polyurethane foam plastic, released with thiourea solution, and determined by inductively coupled plasma-atomic emission spectrometry and flame atomic absorption spectrometry. Based on the characteristic of the copper matte and sinter containing copper, the effects of sample dissolving condition, matrix effect and interference of coexisting elements were investigated. The accuracy, precision and detection limit were discussed. The results of test show that both of the two methods were suitable for determining the contents of gold in copper matte and sintered copper material. PMID:21800614

Ge, Yu-wei; Xiao, Li-mei; Suo, Jin-ling; Wang, Cheng; Hu, Xiao-min; Zhao, Shu-yun

2011-05-01

205

The roles of zinc selenide sandwiched between organic layers and its applications in white light-emitting diodes  

NASA Astrophysics Data System (ADS)

In this paper, the roles of zinc selenide (ZnSe) sandwiched between organic layers, i.e. organic/ZnSe/aluminum quinoline (Alq3), have been studied by varying device structure. A broad band emission was observed from ITO/poly(N-vinylcarbazole)(PVK)(80 nm)/ZnSe(120 nm)/ Alq3(15 nm)/Al under electric fields and it combined the emissions from the bulk of PVK, ZnSe and Alq3, however, emission from only Alq3 was observed from trilayer device ITO/N,N-bis-(1-naphthyl)-N,N-diphenyl-1, 1?-biphenyl-4, 4?-diamine (NPB) (40 nm)/ZnSe(120 nm)/ Alq3(15 nm)/Al. Consequently the luminescence mechanism in the ZnSe layer is suggested to be charge carrier injection and recombination. By thermal co-evaporating Alq3 and 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), we get white light emission with a Commission Internationale de l’E clairage (C.I.E) co-ordinates of (0.32, 0.38) from device ITO/PVK(80 nm)/ZnSe(120 nm)/ Alq3:DCJTB(0.5 wt% DCJTB)(15 nm)/Al at 15 V and the device performs stably with increasing applied voltages.

Yang, Shengyi; Jiang, Yan; Teng, Feng; Xu, Zheng; Hou, Yanbing; Xu, Xurong

2006-08-01

206

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

USGS Publications Warehouse

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

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

2003-01-01

207

Electronic structure of vacancy-ordered iron-selenide K0.5Fe1.75Se2  

NASA Astrophysics Data System (ADS)

The electronic structure of the vacancy-ordered K0.5Fe1.75Se2 iron-selenide compound (278 phase) is studied using the first-principles density functional method. The ground state of the 278 phase is stripelike antiferromagnetic, and its bare electron susceptibility shows a large peak around (?,?) in the folded Brillouin zone. Near the Fermi level, the density of states is dominated by the Fe-3d orbitals, and both electronlike and holelike Fermi surfaces appear in the Brillouin zone. An unfolded band structure shows limited similarities to a hole-doped 122 phase. With 0.1e electron doping, the susceptibility peak is quickly suppressed and broadened, while the two dimensionality of the electronlike Fermi surfaces is greatly enhanced, resulting in a better nesting behavior. Our study should be relevant to the recently reported superconducting phase K0.5+xFe1.75+ySe2 with both x and y being very tiny.

Cao, Chao; Zhang, Fuchun

2013-04-01

208

Influence of substrate temperature on the structural, optical and electrical properties of zinc selenide (ZnSe) thin films  

NASA Astrophysics Data System (ADS)

Zinc selenide (ZnSe) thin films were deposited onto well cleaned silicon (100) and glass substrates at different substrate temperatures (483-589 K) using vacuum evaporation method under a vacuum of 4 × 10-3 Pa. The compositions of the deposited films were determined by Rutherford backscattering spectrometry and the percentage of iodine concentration is calculated as (ZnSe)I0.001. The x-ray diffractograms reveal the cubic structure of the film oriented along the (111) direction. In optical studies, the transition of the deposited film is found to be a direct allowed transition. The optical energy gaps of the deposited films are found to be in the range from 2.72 to 2.60 eV. ZnSe/silicon Schottky diodes were fabricated. From the current-voltage measurement the ideality factor was found to be in the range 2.01-3.51. From the capacitance-voltage studies, the built in potential was found to be 1.51 V. The values of effective carrier concentration (NA) and the barrier height are calculated as 4.37 × 1011 cm-3 and 1.95 eV, respectively.

Venkatachalam, S.; Mangalaraj, D.; Narayandass, Sa K.

2006-11-01

209

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

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

210

Sulfur and selenium isotope separation by distillation. [ch/sub 3/SH, dimethy selenide, H/sub 2/Se  

SciTech Connect

Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of these isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separation of /sup 32/S vs. /sup 34/S were 1.127 for H/sub 2/S, 1.048 for COS, 0.838 for SF/sub 4/, and 1.058 for CH/sub 3/SH. Relative volatilities of /sup 32/S vs. /sup 34/S are 1.0006 for COS and 0.9976 for SF/sub 4/. There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H/sub 2/Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produced separated isotopes with an effect similar to that found for sulfur in SF/sub 4/. 8 refs., 2 tabs.

Mills, T. R.; McInteer, B. B.; Montoya, J. G.

1988-01-01

211

Atomized copper powders  

Microsoft Academic Search

For the first time in the Soviet Union pilot-plant batches of copper powder have been produced by the method of atomization of melts with water under high pressure. The powder produced is characterized by increased apparent density and flowability. The best compressibility (2–6 tons\\/cm2) is exhibited by the powder after annealing. The compressibility of the powder in the as-atomized condition

A. N. Karibyan; A. B. Medvedovskii; V. A. Belyakov; N. S. Sarkisyan; N. G. Dyuzhakova; O. S. Nichiporenko; V. T. Aivazyan; V. P. Poteshkina; Yu. I. Naida

1981-01-01

212

Direct Production of Copper  

NASA Astrophysics Data System (ADS)

The use of commercially pure oxygen in flash smelting a typical chalcopyrite concentrate or a low grade comminuted matte directly to copper produces a large excess of heat. The heat balance is controlled by adjusting the calorific value of the solid feed. A portion of the sulfide material is roasted to produce a calcine which is blended with unroasted material, and the blend is then autogeneously smelted with oxygen and flux directly to copper. Either iron silicate or iron calcareous slags are produced, both being subject to a slag cleaning treatment. Practically all of the sulfur is contained in a continuous stream of SO2 gas, most of which is strong enough for liquefaction. A particularly attractive feature of these technologies is that no radically new metallurgical equipment needs to be developed. The oxygen smelting can be carried out not only in the Inco type flash furnace but in other suitable smelters such as cyclone furnaces. Another major advantage stems from abolishion of the ever-troublesome converter aisle, which is replaced with continuous roasting of a fraction of the copper sulfide feed.

Victorovich, G. S.; Bell, M. C.; Diaz, C. M.; Bell, J. A. E.

1987-09-01

213

Copper intercalation into graphite  

NASA Astrophysics Data System (ADS)

An electric brush is necessary for an electric motor to function. The purpose of this thesis is to propose a technique to improve electric brush properties in an effort to produce a more proficient electric motor by creating a new brush material with improved properties and performance. There are many applications for electric motors and each application would benefit from overall, increased proficiency. Understanding the role an electric brush plays within an electric motor is crucial to improving functionality. The proposed technique to create a novel graphite-copper material involves a two-step procedure that will intercalate CuCl2 into the graphite structure, and then by chemical reduction, will reduce the CuCl2 and result in the final products of copper and graphite. The proposed technique seeks to successfully increase the conductivity and wear properties of an electric brush by incorporating copper into graphite which will also enhance the properties of an electric motor. This thesis will detail the procedures of data collection and how to analyze results of the proposed technique. Expected results will also be discussed utilizing preliminary data collected utilizing XRD, SEM, TGA, and BET equipment. Finally, struggles and challenges of such a technique will also be discussed as well as plans for future work on the proposed technique.

Kalbus, Kyle

214

"Myelodysplasia," myeloneuropathy, and copper deficiency.  

PubMed

We describe a patient with a suspected myelodysplastic syndrome that developed in association with a neurologic disorder resembling subacute combined degeneration but without vitamin B12 deficiency. Ultimately, the hematologic manifestations and the neurologic syndrome were linked to severe copper deficiency. Prompt and complete reversal of the hematologic abnormalities occurred with copper replacement. Serum copper determination should be included in the work-up of patients with anemia and leukopenia of unclear etiology who have associated myeloneuropathy. The hematologic picture can resemble sideroblastic anemia or myelodysplastic syndrome. Hyperzincemia can be an accompanying abnormality even without exogenous zinc ingestion. The reason for the copper deficiency may not be evident. PMID:16007901

Kumar, Neeraj; Elliott, Michelle A; Hoyer, James D; Harper, Charles M; Ahlskog, J Eric; Phyliky, Robert L

2005-07-01

215

21 CFR 73.2647 - Copper powder.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

216

21 CFR 73.2647 - Copper powder.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Copper powder. 73.2647 Section 73.2647...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity...

2009-04-01

217

Embrittlement of Gun Steel by Copper.  

National Technical Information Service (NTIS)

Metallographic examination of the bore surfaces of cannon tubes revealed a close association of copper with the erosion and cracking that occurs during firing. Metallic copper, transferred by abrasive contact between the steel surface and the copper rotat...

A. Szirmae M. H. Kamdar R. M. Fisher

1984-01-01

218

Biological Effects of Copper and Arsenic Pollution.  

National Technical Information Service (NTIS)

Inhibitory effects of copper toward marine microorganisms were studied. Phosphate was found to prevent copper inhibition. Growth and phosphate flux kinetics were described. These phosphate limited systems were found to be copper sensitive only under condi...

D. K. Button S. S. Dunker

1971-01-01

219

21 CFR 73.2647 - Copper powder.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

220

Removal of copper from ferrous scrap  

DOEpatents

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.

Blander, M.; Sinha, S.N.

1987-07-30

221

Recovery of dissipated copper and the future of copper supply  

Microsoft Academic Search

There is a substantial dissipation of copper leading to dilute copper contamination of soils. Extraction of dissipated metals from soils has been advocated as a means of resource conservation. However, proposals that have been brought forward to generate resources from dissipated metals will run into staggering practical problems, associated with, for instance, claims on water and land, if resource generation

L. Reijnders

2003-01-01

222

40 CFR 180.538 - Copper; tolerances for residues.  

Code of Federal Regulations, 2010 CFR

...established in water, potable for residues of copper resulting from the use of the algicides or herbicides basic copper carbonate (malachite), copper sulfate, copper monoethanolamine, and copper triethanolamine to control aquatic plants in reservoirs,...

2009-07-01

223

Synthesis of copper/copper oxide nanoparticles by solution plasma  

NASA Astrophysics Data System (ADS)

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.

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

2011-07-01

224

Network disruption and modification in arsenic and germanium chalcogenides by the addition of univalent metal sulfides and selenides: Comparisons with network disruption and modification in zirconium silicate alloys  

Microsoft Academic Search

The addition of the tetravalent metal oxide, ZrO2, into non-crystalline (nc-) SiO2 to form thin film nc-Zr silicates, and the univalent metal sulfides (selenides), (Cu,Ag)2S(Se), into nc-As2S(Se)3 and -GeS(Se)2 networks to form nc-thin film and\\/or bulk Ag and Cu chalcogenide alloys are compared. The bonding coordination of representative metal-atoms, generally (i) 4 for Cu, (ii) 3 for Ag, and (ii)

G. Lucovsky; J. C. Phillips

2006-01-01

225

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...

226

Beryllium Copper in Instrument Design  

Microsoft Academic Search

The physical characteristics of beryllium copper are described with particular reference to elastic properties. The usefulness of this alloy for instrument springs and similar parts is shown to be in its combination of high elastic limit with relatively low elastic modulus. The bearing of these and of other properties of beryllium copper upon the problems of arriving at appropriate deflexions

L B Hunt

1944-01-01

227

Textured Carbon Surfaces on Copper.  

National Technical Information Service (NTIS)

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 characteri...

A. N. Curren K. A. Jensen R. F. Roman

1984-01-01

228

Diagnosis of Copper Transport Disorders  

PubMed Central

Techniques for the diagnosis of copper transport disorders are increasingly important due to recent recognition of previously unappreciated clinical phenotypes and emerging advances in the treatment of these conditions. Here, we collate the diagnostic approaches and techniques currently employed for biochemical and molecular assessment of at-risk individuals in whom abnormal copper metabolism is suspected.

M?ller, Lisbeth B.; Hicks, Julia D.; Holmes, Courtney S.; Goldstein, David S.; Brendl, Cornelia; Huppke, Peter; Kaler, Stephen G.

2011-01-01

229

Copper chip technology  

NASA Astrophysics Data System (ADS)

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

Edelstein, Daniel C.

1998-08-01

230

Copper chip technology  

NASA Astrophysics Data System (ADS)

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

Edelstein, Daniel C.

1998-09-01

231

Copper chip technology  

NASA Astrophysics Data System (ADS)

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

Edelstein, Daniel C.

1998-09-01

232

Copper chip technology  

NASA Astrophysics Data System (ADS)

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

Edelstein, Daniel C.

1998-08-01

233

Copper chip technology  

NASA Astrophysics Data System (ADS)

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

Edelstein, Daniel C.

1998-09-01

234

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

Microsoft Academic Search

Little is known about how the growth of trihalomethanes (THMs) in drinking water is affected in copper pipe. The formation of THMs and chlorine consumption in copper pipe under stagnant flow conditions were investigated. Experiments for the same water held in glass bottles were performed for comparison. Results showed that although THMs levels firstly increased in the presence of chlorine

Bo Li; Jiuhui Qu; Huijuan Liu; Chengzhi Hu

2007-01-01

235

Copper chaperones. The concept of conformational control in the metabolism of copper.  

PubMed

Copper chaperones compose a specific class of proteins assuring safe handling and specific delivery of potentially harmful copper ions to a variety of essential copper proteins. Copper chaperones are structurally heterogeneous and can exist in multiple metal-loaded as well as oligomeric forms. Moreover, many copper chaperones can exist in various oxidative states and participate in redox catalysis, connected with their functioning. This review is focused on the analysis of the structural and functional properties of copper chaperones and their partners, which allowed us to define specific regulatory principles in copper metabolism connected with copper-induced conformational control of copper proteins. PMID:23684646

Palumaa, Peep

2013-05-16

236

The influence of chloride on interface kinetics and morphology of copper electrodeposits on copper single crystals  

Microsoft Academic Search

The influence of chloride on the kinetics and morphology of copper electrodeposition on copper single crystal in acidified copper sulfate solution was studied by atomic force microscopy (AFM) and by electro-analytical methods. AFM was employed to image deposits on low-index single crystal copper surface formed under potential control in a fluid electrolyte. The kinetic parameters for cathodic deposition of copper

Qunwei Wu

1998-01-01

237

Sodium borohydride efficiently removes copper from amino acid–copper complexes  

Microsoft Academic Search

Sodium borohydride very efficiently removed copper from amino acid–copper complexes. The copper in the amino acid–copper complex was reduced to insoluble copper(I) oxide and the free amino acid was released in pure form. This method is rapid, nontoxic and inexpensive compared to the currently used methods.

Gummadi Sailaja; Shaik Nowshuddin; M. N. A. Rao

2004-01-01

238

Tellurides, selenides and Bi-mineral assemblages from the Río Narcea Gold Belt, Asturias, Spain: genetic implications in Cu-Au and Au skarns  

NASA Astrophysics Data System (ADS)

Gold ores in skarns from the Río Narcea Gold Belt are associated with Bi-Te(-Se)-bearing minerals. These mineral assemblages have been used to compare two different skarns from this belt, a Cu-Au skarn (calcic and magnesian) from the El Valle deposit, and a Au-reduced calcic skarn from the Ortosa deposit. In the former, gold mineralization occurs associated with Cu-(Fe)-sulfides (chalcopyrite, bornite, chalcocite-digenite), commonly in the presence of magnetite. Gold occurs mainly as native gold and electrum. Au-tellurides (petzite, sylvanite, calaverite) are locally present; other tellurides are hessite, clausthalite and coloradoite. The Bi-bearing minerals related to gold are Bi-sulfosalts (wittichenite, emplectite, aikinite, bismuthinite), native bismuth, and Bi-tellurides and selenides (tetradymite, kawazulite, tsumoite). The speciation of Bi-tellurides with Bi/Te(Se + S) ? 1, the presence of magnetite and the abundance of precious metal tellurides and clausthalite indicate fO2 conditions within the magnetite stability field that locally overlap the magnetite-hematite buffer. In Ortosa deposit, gold essentially occurs as native gold and maldonite and is commonly related to pyrrhotite and to the replacement of löllingite by arsenopyrite, indicating lower fO2 conditions for gold mineralization than those for El Valle deposit. This fact is confirmed by the speciation of Bi-tellurides and selenides (hedleyite, joséite-B, joséite-A, ikunolite-laitakarite) with Bi/Te(+ Se + S) ? 1.

Cepedal, A.; Fuertes-Fuente, M.; Martín-Izard, A.; González-Nistal, S.; Rodríguez-Pevida, L.

2006-07-01

239

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)

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.

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

2013-08-01

240

2-Pyridyl selenolates of antimony and bismuth: Synthesis, characterization, structures and their use as single source molecular precursor for the preparation of metal selenide nanostructures and thin films.  

PubMed

Reactions of SbCl(3) and BiCl(3) with M'Se-C(5)H(3)(R-3)N (M' = Li or Na; R = H or Me) gave homoleptic selenolate complexes of the general formula [M{Se-C(5)H(3)(R-3)N}(3)] (M = Sb or Bi). The complexes were characterized by elemental analysis, UV-vis and NMR ((1)H, (13)C and (77)Se) spectroscopy. The single crystal X-ray analysis of [M{Se-C(5)H(3)(Me-3)N}(3)].nH(2)O (M/n = Sb/1.5 and Bi/0.5) revealed that the antimony complex adopts a trigonal pyramidal configuration with monodentate selenolate ligands while the bismuth analogue acquires a distorted square pyramidal configuration defined by two chelating and one monodentate selenolate groups. Pyrolysis of [M{Se-C(5)H(3)(Me-3)N}(3)] either in a furnace or in hexadecylamine (HDA) at different temperatures gave a variety of M(2)Se(3) nanostructures. Thin films of metal selenides have also been deposited on glass substrate by aerosol-assisted chemical vapor deposition (AACVD). Both nanostructures and thin films of metal selenides were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). PMID:20714620

Sharma, Rakesh K; Kedarnath, G; Jain, Vimal K; Wadawale, Amey; Nalliath, Manoj; Pillai, C G S; Vishwanadh, B

2010-08-12

241

Copper-nickel alloys for marine applications  

Microsoft Academic Search

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

Carol A. Powell; James F. Jenkins

2000-01-01

242

The Role of Copper in Neurodegenerative Disease  

Microsoft Academic Search

Copper is an essential trace metal which plays a fundamental role in the biochemistry of the human nervous system. Menkes disease and Wilson disease are inherited disorders of copper metabolism and the dramatic neurodegenerative phenotypes of these two diseases underscore the essential nature of copper in nervous system development as well as the toxicity of this metal when neuronal copper

Darrel J. Waggoner; Thomas B. Bartnikas; Jonathan D. Gitlin

1999-01-01

243

Nano copper conductive ink for RFID application  

Microsoft Academic Search

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

Jian Li; Bing An; Jian Qin; Yiping Wu

2011-01-01

244

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2011 CFR

...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 pipe...

2011-10-01

245

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2010 CFR

...Transportation 3 2009-10-01 2009-10-01 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 pipe...

2009-10-01

246

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2012 CFR

...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 pipe...

2012-10-01

247

49 CFR 192.279 - Copper pipe.  

Code of Federal Regulations, 2010 CFR

...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 pipe...

2010-10-01

248

Homogeneous Copper-Catalyzed Oxidations  

Microsoft Academic Search

The bioinorganic chemistry of copper has provided a stimulating background for exciting research\\u000a on homogeneous copper-catalyzed reactions in recent years, and this review starts with a brief and\\u000a concise overview of the role of copper containing active sites in metalloproteins that catalyze oxidation\\u000a or oxygenation reactions in nature. Efficient bio-inspired Cu-based catalysts for a variety of chemical\\u000a oxidative transformations have been developed over

Jarl Ivar van der Vlugt; Franc Meyer

249

Selecting copper and copper alloys; Part 2: Cast products  

SciTech Connect

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.

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

250

Irradiation effects on copper  

NASA Astrophysics Data System (ADS)

Copper, one of the most significant metals, is exposed to IR radiation. A Nd:YAG laser (1064 nm, 1.1 MW, 12 ns) has been used to irradiate fine polished and annealed samples (4 N, 1×1×0.3 cm3) with 100 laser shots under a vacuum of ˜10-6 torr. The laser focal spot size and power density on the target were 12 ?m and 3×1012 Wm-2 respectively. The surface and structural studies were performed by analyzing scanning electron micrographs and X-ray diffractograms (XRDs), respectively. Laser ablation results in boiling, splashing, hydrodynamical sputtering and exfoliation along with other relevant phenomena. The XRD patterns of the exposed sample indicate a change in diffraction intensity and grain sizes. The atomic planes remain undisturbed for the irradiated target. The information collected is useful for investigating the complexities found in radiation-metal interactions.

Latif, Anwar; Khaleeq-Ur-Rahman, M.; Rafique, M. S.; Bhatti, K. A.; Imran, M.

251

NID Copper Sample Analysis  

SciTech Connect

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.

Kouzes, Richard T.; Zhu, Zihua

2011-09-12

252

Use of Cement Copper in an Iron-Copper-Carbon Powder Metallurgy Alloy.  

National Technical Information Service (NTIS)

An investigation was made of the substitution of cement copper powder for commercial copper powder in an Fe-7 pct Cu-1 pct C powder metallurgy alloy. Copper powders from six different commercial cementation operations were separately upgraded by screening...

R. L. Crosby D. H. Desy R. M. Doerr

1970-01-01

253

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

Code of Federal Regulations, 2010 CFR

...Cosmetics § 73.2125 Potassium sodium copper chlorophyllin...The color additive potassium sodium copper chlorophyllin...and (b). (b) Uses and restrictions. Potassium sodium copper chlorophyllin...Sorbitol. Magnesium phosphate, tribasic....

2009-04-01

254

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

Code of Federal Regulations, 2010 CFR

...Cosmetics § 73.2125 Potassium sodium copper chlorophyllin...The color additive potassium sodium copper chlorophyllin...and (b). (b) Uses and restrictions. Potassium sodium copper chlorophyllin...Sorbitol. Magnesium phosphate, tribasic....

2010-04-01

255

Tetraphenylphosphonium copper(I) dicyanamide  

Microsoft Academic Search

In the title compound, {l_brace}(CHP)[Cu(CN)]{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.

J. A. Schlueter; U. Geiser

2007-01-01

256

Majorana Electroformed Copper Mechanical Analysis  

SciTech Connect

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

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

2012-04-30

257

Viscoplastic Theory Applied to Copper.  

National Technical Information Service (NTIS)

A phenomenologically based viscoplastic model is derived for copper. The model is thermodynamically constrained by the condition of material dissipativity. Two internal state variables are considered. The back stress accounts for strain-induced anisotropy...

A. D. Freed M. J. Verrilli

1988-01-01

258

Application of saccharose as copper(II) ligand for electroless copper plating solutions  

Microsoft Academic Search

Saccharose, forming sufficiently stable complexes with copper(II) ions in alkaline solutions, was found to be a suitable ligand for copper(II) chelating in alkaline (pH>12) electroless copper deposition solutions. Reduction of copper(II)–saccharose complexes by hydrated formaldehyde was investigated and the copper deposits formed were characterized. The thickness of the compact copper coatings obtained under optimal operating conditions in 1h reaches ca.

Eugenijus Norkus; K?stutis Prušinskas; Algirdas Vaškelis; Jan? Ja?iauskien?; Irena Stalnionien?; Donald L. Macalady

2007-01-01

259

FAST Copper For Broadband Access  

Microsoft Academic Search

This is an overview of the ongoing FAST Copper project, which is aimed at substantial improvements in rate, reach, reliability, and quality in copper-last-mile broadband access through fiber\\/DSL deployment, engineering innovations, and fundamental research. The project is funded by NSF, and is currently pursued jointly by Princeton University, Stanford University, and Fraser Research Lab. In this article, we out- line

Mung Chiang; Jianwei Huang; Dahai Xu; Yung Yi; Chee Wei Tan; Raphael Cendrillon

260

Recent advances in copper radiopharmaceuticals.  

PubMed

Copper has five radioisotopes ((60)Cu, (61)Cu, (62)Cu, (64)Cu, and (67)Cu) that can be used in copper radiopharmaceuticals. These radioisotopes decay by mixed emissions of ?+, ?-, and ? with a wide range of half-lives from 9.74 min ((62)Cu) to 2.58 d ((67)Cu), which enable the design and synthesis of a variety of radiopharmaceuticals for different biomedical applications in diagnostic and therapeutic nuclear medicine. However, due to the availability and production cost, the research efforts in copper radiopharmaceuticals are mainly focused on the use of (64)Cu (t(1/2) = 12.7 h; 17.4% ?+, 43% EC, 39% ?-), a radioisotope with low positron energy (E ?+max = 0.656 MeV) that is ideal for positron emission tomography (PET) imaging quantification and ?- emissions along with Auger electron for radiotherapy. Driven by the ever-increasing availability of preclinical and clinical PET scanners, a considerable interest has been seen in the development of novel copper radiopharmaceuticals in the past decade for a variety of diseases as represented by PET imaging of cancer. To avoid unnecessary literature redundancy, this review focuses on the unrepresented research aspects of copper chemistry (e.g. electrochemistry) and their uses in the evaluation of novel nuclear imaging probe design and recent advances in the field towards the practical use of copper radiopharmaceuticals. PMID:22191650

Hao, Guiyang; Singh, Ajay N; Oz, Orhan K; Sun, Xiankai

2011-04-01

261

Porins Increase Copper Susceptibility of Mycobacterium tuberculosis.  

PubMed

Copper resistance mechanisms are crucial for many pathogenic bacteria, including Mycobacterium tuberculosis, during infection because the innate immune system utilizes copper ions to kill bacterial intruders. Despite several studies detailing responses of mycobacteria to copper, the pathways by which copper ions cross the mycobacterial cell envelope are unknown. Deletion of porin genes in Mycobacterium smegmatis leads to a severe growth defect on trace copper medium but simultaneously increases tolerance for copper at elevated concentrations, indicating that porins mediate copper uptake across the outer membrane. Heterologous expression of the mycobacterial porin gene mspA reduced growth of M. tuberculosis in the presence of 2.5 ?M copper by 40% and completely suppressed growth at 15 ?M copper, while wild-type M. tuberculosis reached its normal cell density at that copper concentration. Moreover, the polyamine spermine, a known inhibitor of porin activity in Gram-negative bacteria, enhanced tolerance of M. tuberculosis for copper, suggesting that copper ions utilize endogenous outer membrane channel proteins of M. tuberculosis to gain access to interior cellular compartments. In summary, these findings highlight the outer membrane as the first barrier against copper ions and the role of porins in mediating copper uptake in M. smegmatis and M. tuberculosis. PMID:24013632

Speer, Alexander; Rowland, Jennifer L; Haeili, Mehri; Niederweis, Michael; Wolschendorf, Frank

2013-09-06

262

Process Of Bonding Copper And Tungsten  

DOEpatents

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.

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

2000-07-18

263

NID Copper Sample Analysis  

SciTech Connect

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.

Kouzes, Richard T.; Zhu, Zihua

2011-02-01

264

Catecholase activity associated with copper-S100B.  

PubMed

This study addresses the spectroscopic properties and reactivity associated with the copper-loaded form of S100B isolated from bovine brain. Copper(II)-S100B displays EPR features typical of a type II copper center and is shown here to exhibit catecholase activity, the two-electron oxidation of catechols. The steady-state kinetics associated with the oxidation of several catecholamines has been probed in order to further characterize this activity. The evidence provided indicates that the catecholase chemistry is copper initiated. Superoxide dismutase has no effect on the rates of catecholamine oxidation catalyzed by Cu-S100B, establishing that superoxide is not produced during this reaction, ruling out an autoxidative mechanism. Addition of catalase to the Cu-S100B reaction with catechols reduces the amount of oxygen consumed by 50%, demonstrating that peroxide is released during this reaction. The release of peroxide is mechanistically distinct from the type III dinuclear copper proteins, catechol oxidase and tyrosinase. PMID:12693934

Senior, SueAnn Z; Mans, Laura L; VanGuilder, Heather D; Kelly, Kimberly A; Hendrich, Michael P; Elgren, Timothy E

2003-04-22

265

Beryllium–copper reactivity in an ITER joining environment  

Microsoft Academic Search

Beryllium–copper reactivity was studied using test parameters being considered for use in the ITER reactor. In this application, beryllium–copper tiles are produced using a low-temperature copper–copper diffusion bonding technique. Beryllium is joined to copper by first plating the beryllium with copper followed by diffusion bonding the electrodeposited (ED) copper to a wrought copper alloy (CuNiBe) at 450°C, 1–3 h using

B. C. Odegard; C. H. Cadden; N. Y. C. Yang

1998-01-01

266

Ternary lanthanum sulfide selenides ?-LaS2-xSex (0  

NASA Astrophysics Data System (ADS)

Mixed lanthanum sulfide selenides LaS2-xSex (0

Bartsch, Christian; Doert, Thomas

2012-01-01

267

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)

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.

Vápenka, D.; Václavík, J.; Mokrý, P.

2013-04-01

268

Electric performance and photosensitivity of heterostructures prepared by thermal decomposition of a gallium nitrate aqueous solution on an indium selenide (0001) cleaved surface  

NASA Astrophysics Data System (ADS)

It is shown that thermal decomposition of a gallium nitrate aqueous solution on the surface of a semiconductor in air can basically be used for preparing structures sensitive to radiation from in the near-UV spectral range. The electric and photovoltaic properties of Ga2O3- n-( p-)InSe heterostructures are studied. It is found that a high-ohmic layer arising at the InSe-Ga2O3 interface affects not only the electric performance but also the photoelectric spectra of the heterostructures. It is supposed that current instability with Z- and N-shaped reverse branches in the I- V characteristics of the Ga2O3- p-InSe structures stems from doping nonuniformity in the bulk of quasi-two-dimensional p-type indium selenide.

Drapak, S. I.; Yurtsenyuk, N. S.; Kovalyuk, Z. D.

2009-03-01

269

Copper(II) Complexes with Subnormal Magnetic Moments.  

National Technical Information Service (NTIS)

On the basis of present investigations, copper(II) compounds with subnormal magnetic moments can be roughly divided into two types. Those with direct copper-to-copper interaction have short copper-to-copper distances. In these compounds, of which copper(I...

M. Kato H. B. Jonassen J. C. Fanning

1964-01-01

270

Biliary copper excretion by hepatocyte lysosomes in the rat. Major excretory pathway in experimental copper overload  

SciTech Connect

We investigated the hypothesis that lysosomes are the main source of biliary copper in conditions of hepatic copper overload. We used a rat model of oral copper loading and studied the relationship between the biliary output of copper and lysosomal hydrolases. Male Sprague-Dawley rats were given tap water with or without 0.125% copper acetate for up to 36 wk. Copper loading produced a 23-fold increase in the hepatic copper concentration and a 30-65% increase in hepatic lysosomal enzyme activity. Acid phosphatase histochemistry showed that copper-loaded livers contained an increased number of hepatocyte lysosomes; increased copper concentration of these organelles was confirmed directly by both x ray microanalysis and tissue fractionation. The copper-loaded rats showed a 16-fold increase in biliary copper output and a 50-300% increase in biliary lysosomal enzyme output. In the basal state, excretory profiles over time were similar for biliary outputs of lysosomal enzymes and copper in the copper-loaded animals but not in controls. After pharmacologic stimulation of lysosomal exocytosis, biliary outputs of copper and lysosomal hydrolases in the copper-loaded animals remained coupled: injection of colchicine or vinblastine produced an acute rise in the biliary output of both lysosomal enzymes and copper to 150-250% of baseline rates. After these same drugs, control animals showed only the expected increase in lysosomal enzyme output without a corresponding increase in copper output. We conclude that the hepatocyte responds to an increased copper load by sequestering excess copper in an increased number of lysosomes that then empty their contents directly into bile. The results provide direct evidence that exocytosis of lysosomal contents into biliary canaliculi is the major mechanism for biliary copper excretion in hepatic copper overload.

Gross, J.B. Jr.; Myers, B.M.; Kost, L.J.; Kuntz, S.M.; LaRusso, N.F.

1989-01-01

271

Hydrogen reduction of copper bleed solution from an Indian copper smelter for producing high purity copper powders  

Microsoft Academic Search

A bench scale investigation on the hydrogen reduction of a highly acidic copper bleed solution to produce high purity copper powder is discussed in this paper. A titanium lined autoclave of 1 L capacity was used for this study. The parameters optimized on the bench scale were validated by performing hydrogen reduction of copper in a larger autoclave. Effect of various

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

2006-01-01

272

Quantitative analysis of copper, zinc and copper\\/zinc ratio in selected human brain tumors  

Microsoft Academic Search

Summary Serum copper and zinc concentrations and copper\\/zinc ratios have been shown to be increased in several types of human malignancies, including human brain tumors. In this study, copper and zinc levels and copper\\/zinc ratios were determined by atomic absorption analysis in tissue and serum from 29 primary and metastatic brain tumor patients. Metastatic carcinomas and malignant gliomas revealed significantly

Daizo Yoshida; Yukio Ikeda; Shozo Nakazawa

1993-01-01

273

Copper deficiency myeloneuropathy resembling B12 deficiency: partial resolution of MR imaging findings with copper supplementation.  

PubMed

Copper deficiency has been associated with a clinical syndrome, myeloneuropathy. Radiographic changes resembling B(12) deficiency in the cervical spinal cord have been described. We present a case of copper deficiency myeloneuropathy, with cervical MR imaging findings resembling B(12) deficiency, which partially reversed following copper supplementation. This is, to our knowledge, the first described case of radiographic improvement with copper supplementation. PMID:17110677

Goodman, B P; Chong, B W; Patel, A C; Fletcher, G P; Smith, B E

274

Recovering Copper Values from Oxidized Ores.  

National Technical Information Service (NTIS)

A process is presented for recovering copper from oxidized ores such as azurite, malachite or chrysacolla. This is done by alkaline leachants having incorporated therein siliceous material to inhibit the dehydration of the formed copper complex. This perm...

P. R. Haskett D. J. Bauer C. H. Elges R. E. Lindstrom

1976-01-01

275

Leaching of Copper Ore by Thiobacillus Ferrooxidans.  

ERIC Educational Resources Information Center

|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)|

Lennox, John; Biaha, Thomas

1991-01-01

276

Copper plating the ground test accelerator RFQ.  

National Technical Information Service (NTIS)

The copper-plating process for the Ground Test Accelerator (GTA) radio frequency quadrupole (RFQ) vanes required a full development program and tight quality control procedures. The copper plating development program utilized full-size RFQ major and minor...

H. Mignardot J. Uher

1991-01-01

277

Extraction of Copper from Sulfide Ores.  

National Technical Information Service (NTIS)

In the patent application copper is extracted from sulfide ores or concentrates by electrolysis in a cell having separate anode and cathode sections, and having an intermediate liquid copper-mercury alloy electrode between the anode and cathode sections.

T. A. Henrie R. E. Lindstrom K. P. V. Lei

1976-01-01

278

Tissue copper determinations by neutron activation analysis  

PubMed Central

A method is described for the handling of tissue samples for copper determination by neutron activation analysis. The results obtained for normal liver copper estimations compared favourably with results obtained by conventional methods. Images

Todd, A. P.; Thorpe, M. E. C.; Rosenoer, V. M.

1967-01-01

279

Determination of copper in clarified apple juices.  

PubMed

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

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

2010-03-24

280

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

SciTech Connect

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

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

1988-07-01

281

Application of saccharose as copper(II) ligand for electroless copper plating solutions.  

PubMed

Saccharose, forming sufficiently stable complexes with copper(II) ions in alkaline solutions, was found to be a suitable ligand for copper(II) chelating in alkaline (pH>12) electroless copper deposition solutions. Reduction of copper(II)-saccharose complexes by hydrated formaldehyde was investigated and the copper deposits formed were characterized. The thickness of the compact copper coatings obtained under optimal operating conditions in 1h reaches ca. 2 microm at ambient temperature. The plating solutions were stable and no signs of Cu(II) reduction in the bulk solution were observed. Results were compared with those systems operating with other copper(II) ligands. PMID:17109836

Norkus, Eugenijus; Prusinskas, Kestutis; Vaskelis, Algirdas; Jaciauskiene, Jane; Stalnioniene, Irena; Macalady, Donald L

2006-10-27

282

Copper sulfide coated polysulfone films  

NASA Astrophysics Data System (ADS)

The modification of polysulfone surface was used to obtain effective interactions between an organic polymeric surface and an inorganic specie. A previous treatment of the polymer surface with modifiers is required in order to provide adherence. Our objective was the synthesis and the surface characterization of copper sulfide coated polysulfone (CuS PSf) films. SEM micrographs showed a homogeneous distribution of copper sulfide, which contributes to increasing electrical conductivity. X-ray analysis showed a decrease in copper sulfide particles (covellite porcelain) when compared with other polymeric composites prepared under similar conditions. The measured surface conductivity of the CuS PSf films was higher than those of other similar systems, ca. 800 S cm-1.

Kunita, M. H.; Rinaldi, A. W.; Girotto, E. M.; Radovanovic, E.; Muniz, E. C.; Rubira, A. F.

2006-03-01

283

Copper Post-CMP Cleaning  

NASA Astrophysics Data System (ADS)

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].

Starosvetsky, D.; Ein-Eli, Y.

284

Traveling fronts of copper deposition.  

PubMed

We report the experimental observation of traveling fronts during the electroless deposition of copper on passive steel substrates. The low-carbon steel samples are passivated in nitric acid prior to the plating experiment, thus creating a thin, protective oxide layer on the steel surface. The deposition experiments are carried out from slightly acidic (pH 3.2) copper sulfate solution and copper nitrate solution with the latter showing front propagation only in the presence of chloride ions. For up to 30 s, fronts propagate with constant velocities in the range from 0.5 to 5 mm/s depending on the experimental conditions. This phase of constant-speed propagation gives way to accelerating fronts and very rapid, spatially unstructured deposition. Front-mediated plating is observed over a wide range of cupric ion concentration and constitutes a striking and unexpected example for pattern formation in electrochemical systems. PMID:12197727

Thouvenel-Romans, Stephanie; Agladze, Konstantin; Steinbock, Oliver

2002-09-01

285

Hydrogen damage in friction welded copper joints  

Microsoft Academic Search

The occurrence of hydrogen attack in electrolytic copper and in copper deoxidized with phosphorous, during model heating in oil and in friction welded specimens was investigated. Dissimilar-metal joints, i.e. copper\\/TZM (titanium–zirconium–molybdenum based alloy) joints and copper\\/austenitic steel joints, were subjected to microstructural examinations and tensile strength tests.Microcracks near the weld surface, caused by hydrogen attack, were found to occur in

Andrzej Ambroziak

2010-01-01

286

Grain growth in copper interconnect lines  

Microsoft Academic Search

State-of-the-art copper interconnects are fabricated using a damascene process in which trenches are filled with copper by electro-plating. Similar to electro-plated copper films, the microstructural evolution of copper lines also shows a dependence on their geometric features. In this paper we examine the effect of geometric factors of narrow lines on grain growth. These factors include linewidth, aspect ratio and

W. Wu; D. Ernur; S. H. Brongersma; M. Van Hove; K. Maex

2004-01-01

287

High-temperature oxidation of copper  

NASA Astrophysics Data System (ADS)

Data on the kinetics and thermodynamics of high-temperature oxidation of copper are generalized. The attention is focused on the catastrophic oxidation of copper contacting some low-melting oxides. The results of experimental and theoretical studies of the last 10 years concerning the catastrophic oxidation of copper are analyzed. The theory of catastrophic oxidation of copper under a thin layer of low-melting oxide is considered. The bibliography includes 135 references.

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

2013-03-01

288

Semimanufactured products made of copper and copper alloys: An analysis of production and sale in a world perspective  

NASA Astrophysics Data System (ADS)

Semimanufactured products based on copper or copper alloys were investigated with a view to an economical and technically justified production in copper-exporting developing countries. The structure of the world copper industry is presented. The recycling of copper for industrial applications is discussed. The market for semimanufactured products and the copper market in developing countries is presented.

Sannen, A.

289

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

PubMed Central

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.

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

2008-01-01

290

Developments in the Manufacture of Copper Wire  

Microsoft Academic Search

This paper covers interesting developments in the manufacture of copper wire and contains a description of a copper rod and wire mill designed to meet the new requirements. It also includes a brief survey of the copper rolling and wire drawing art at the time the investigation was started; a summary of tests made in varying the practise in rod

John R. Shea; Samuel McMullan

1927-01-01

291

Copper complexation in the Northeast Pacific  

Microsoft Academic Search

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

KENNETH H. COALE; KENNETH W. BRULAND

1988-01-01

292

Copper accumulation in the crayfish (Orconectes rusticus)  

SciTech Connect

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.

Evans, M.L.

1980-06-01

293

Myeloneuropathy and anemia due to copper malabsorption  

Microsoft Academic Search

Dietary deficiency of copper results in a progressive ataxic myelopathy in ruminants called swayback. Menkes disease is a human disease due to an inherited defect in copper absorption; survival into adulthood is typically not known to occur. We report a 63-year-old woman who was evaluated by us for a myeloneuropathy that occurred in the setting of copper malabsorption. Her neurological

Neeraj Kumar; Phillip A. Low

2004-01-01

294

Copper sequestration using local waste products  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

295

Refining of the Copper and investment casting  

Microsoft Academic Search

The present work deals with the problems of vacuum metallurgy and the method of exact casting of refined copper. Copper refining comprises deoxidation and removal of hydrogen, oxygen as well as some volatile components. The non-solubility of nitrogen in molten metal is also considered.The refining theory in high vacuum copper melting by evaporation is dealt with. On the basis of

1995-01-01

296

The Early History of Insulated Copper Wire  

Microsoft Academic Search

In the early 1800s galvanometers could be constructed with the fine gauges of silk-covered copper or silver wires produced for decorative purposes, but when Faraday was making his classic electrical experiments in 1831 he needed a sturdier gauge of copper wire. Bare copper wire was available in many diameters for mechanical applications, but coils for electromagnetic investigations had to be

Allan A. Mills

2004-01-01

297

21 CFR 524.463 - Copper naphthenate.  

Code of Federal Regulations, 2013 CFR

...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....

2013-04-01

298

21 CFR 73.1647 - Copper powder.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

299

THE EVOLUTION OF SYNTHETICALLY PRECIPITATED COPPER SOLIDS  

EPA Science Inventory

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

300

Copper coating specification for the RHIC arcs  

SciTech Connect

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.

Blaskiewicz, M.

2010-12-01

301

Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats  

Microsoft Academic Search

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 (less than 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 64Cu whole-body retention. Freshly isolated liver parenchymal

G. J. Van den Berg; Goeij de JJM; I. Bock; MJJ Gijbels; A. Brouwer; K. Y. Lei; HFJ Hendriks

1991-01-01

302

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

ScienceCinema

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

303

Joining of alumina via copper/niobium/copper interlayers  

SciTech Connect

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.

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

2000-03-15

304

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

Microsoft Academic Search

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

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

1996-01-01

305

[An uncommon etiology of anemia: copper deficiency].  

PubMed

A 58-year-old patient, without any notable medical history, except for alcoholism and treated hypertension, developed anemia and leukopenia with macrocytosis. Folate deficiency was diagnosed and subsequently treated. Despite folate supplementation, the hematological parameters did not normalize. Further diagnosis investigations were led to search for uncommon etiologies of anemia and leukoneutropenia. We diagnosed severe copper deficiency on the basis of decreased plasma levels of copper and ceruloplasmin. Copper supplementation improved blood counts within three months. This case illustrates hematological disorders due to copper deficiency, initially masked by an associated folate deficiency. The copper deficiency etiology was not identified in this case. PMID:23906580

Kouamou, Edwige; Stépanian, Alain; Khadra, Fadi; de Prost, Dominique; Teillet, France

306

Myeloneuropathy and anemia due to copper malabsorption.  

PubMed

Dietary deficiency of copper results in a progressive ataxic myelopathy in ruminants called swayback. Menkes disease is a human disease due to an inherited defect in copper absorption; survival into adulthood is typically not known to occur. We report a 63-year-old woman who was evaluated by us for a myeloneuropathy that occurred in the setting of copper malabsorption. Her neurological deterioration stopped with copper supplementation. The limited literature on neurological manifestations of acquired copper deficiency suggests that the clinical presentation resembles the myeloneuropathy seen with vitamin B12 deficiency. PMID:15311353

Kumar, Neeraj; Low, Phillip A

2004-06-01

307

Tetraphenylphosphonium copper(I) dicyanamide.  

SciTech Connect

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.

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

2007-01-01

308

Copper sulfate: Liquid or crystals?  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

309

Copper Metalization Using Electroplating Process  

Microsoft Academic Search

Recently, electroplating method which deposits copper films by using cupric sulfate solution, has been proposed. The electroplating method has the advantages of simplicity, safety, low cost, low deposition temperature, high purity, low resistivity, and high capability of gap filling. In this method, an electrical contact is made to the seed layer and a current is passed such that the reaction

Byung Nam Park; Sie Young Choi

2003-01-01

310

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,...

311

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...

312

Building a Copper Pipe "Xylophone."  

ERIC Educational Resources Information Center

|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)|

Lapp, David R.

2003-01-01

313

CopperCore Service Integration  

ERIC Educational Resources Information Center

|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…

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

2007-01-01

314

Depositing copper patterns on teflon  

SciTech Connect

Printed circuit boards composed of patterned cooper features on poly(tetrafluorethylene), better known by the E.I. du Pont de Nemours and Company trade name Teflon, are currently used for high-frequency applications. The choice of these materials is based on the high conductivity of copper and the facts that Teflon has One of the lowest reported dielectric constants ({approximately}2.0). Low dissipation factors. High thermal stability. High chemical resistance. This paper reports that the high conductivity of copper, coupled with the low dielectric constant of Teflon, allows high-frequency operation and/or extensive miniaturization. However, one of Teflon's most important properties is chemical and physical inertness. While this property is extremely attractive in numerous applications involving hostile environments, it presents major problems in metallization for electronic applications. To address this condition, researchers at Sandia National Laboratories and the University of New Mexico have developed a three-step, additive method for the patterned deposition of copper on Teflon. Still, while the example of deposition work examined in this article is recent, it is nonetheless supported by considerable prior work on the patterned etching of Teflon and copper chemical vapor deposition (CVD).

Rye, R.R. (Sandia National Lab. (US)); Hampden-Smith, M.J.; Kodas, T.T. (Univ. of New Mexico, NM (US))

1992-07-01

315

Improved Copper Septum Magnet Design.  

National Technical Information Service (NTIS)

A copper septum magnet of improved design has been developed to replace the existing F5 septum deflector in the slow-extraction channel at the Brookhaven National Laboratory AGS. The new magnet has several novel design features such as a solid rather than...

E. S. Rodger H. L. Weisberg

1981-01-01

316

Building a copper pipe 'xylophone'  

Microsoft Academic Search

Music is central to the life of many students. This article describes using 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-like musical instrument or set of chimes from a 3 m section of copper pipe. The instrument produces a full major scale

David R. Lapp

2003-01-01

317

Process Of Bonding Copper And Tungsten  

DOEpatents

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.

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

1999-11-23

318

Nanotransfer printing for patterning conductive copper features  

NASA Astrophysics Data System (ADS)

The drive for low-cost electronics creates a need for new techniques to directly and inexpensively pattern copper features in the 1-100?m range. We have developed a solventless, additive approach for printing permanent, conductive copper features at ambient conditions. Our technique is analogous to previously established nanotransfer printing (nTP) procedures for patterning gold with one marked difference. When copper is deposited onto a poly(dimethylsiloxane), PDMS, stamp, residual oligomers from the stamp penetrate between copper grains. This penetration disrupts the conductive pathway between copper grains; the printed copper patterns are electrically insulating as a consequence. This phenomenon is not observed with nanotransfer printing of gold features. A simple modification to the patterning procedure -- leaching the PDMS stamps in boiling toluene for 2-3 days to remove uncrosslinked oligomers -- results in printed copper patterns that are electrically conductive, with an average resistivity of 31?ohms-cm.

Dickey, Kimberly; Sun, Yangming; Loo, Yueh Lin

2006-03-01

319

Catastrophic Oxidation of Copper: A Brief Review  

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

320

Controlling Copper Electrochemical Deposition (ECD)  

NASA Astrophysics Data System (ADS)

The implementation of copper processing in semiconductor manufacturing has resulted in major process development and manufacturing challenges. A fundamental understanding of the copper plating processes used in manufacturing has been limited by the lack of in-line methods for direct measurement and control of process chemistry. Plating bath chemistry adjustments and change-out frequencies are currently determined using a combination of indirect electrochemical monitoring techniques, off-line analyses of wafer metrology and analytical lab measurements. There have been a number of industry reports of major process startup delays, yield management problems and reliability issues as a result of these difficulties. A new in-process mass spectrometry (IPMS) approach enables automated, real-time measurement of both the inorganic components and organic additives in the copper electroplating chemistry as they change during production. The tool is not only capable of real time direct quantification of the copper, chloride, pH, and organic additives in the plating bath, but can also monitor additive breakdown byproducts as they occur during the production process. These breakdown products, as well as changes in the original bath constituent composition can be expected to have a major impact on process performance. We are now in the process of measuring longer term plating bath stability and chemistry changes in prototype applications in semiconductor fab manufacturing environments. The first results demonstrate improved process understanding and the potential for greatly improved process control. We will discuss the technical challenges that were successfully addressed in developing the IPMS capability for application to the copper plating process and the initial process data subsequently obtained.

West, Michael; McDonald, Robert; Anderson, Marc; Kingston, Skip; Mui, Rudy

2003-09-01

321

Uptake and internalisation of copper by three marine microalgae: comparison of copper-sensitive and copper-tolerant species.  

PubMed

Although it has been well established that different species of marine algae have different sensitivities to metals, our understanding of the physiological and biochemical basis for these differences is limited. This study investigated copper adsorption and internalisation in three algal species with differing sensitivities to copper. The diatom Phaeodactylum tricornutum was particularly sensitive to copper, with a 72-h IC50 (concentration of copper to inhibit growth rate by 50%) of 8.0 microg Cu L(-1), compared to the green algae Tetraselmis sp. (72-h IC50 47 microg Cu L(-1)) and Dunaliella tertiolecta (72-h IC50 530 microg Cu L(-1)). At these IC50 concentrations, Tetraselmis sp. had much higher intracellular copper (1.97+/-0.01 x 10(-13)g Cu cell(-1)) than P. tricornutum (0.23+/-0.19 x 10(-13)g Cu cell(-1)) and D. tertiolecta (0.59+/-0.05 x 10(-13)g Cu cell(-1)), suggesting that Tetraselmis sp. effectively detoxifies copper within the cell. By contrast, at the same external copper concentration (50 microg L(-1)), D. tertiolecta appears to better exclude copper than Tetraselmis sp. by having a slower copper internalisation rate and lower internal copper concentrations at equivalent extracellular concentrations. The results suggest that the use of internal copper concentrations and net uptake rates alone cannot explain differences in species-sensitivity for different algal species. Model prediction of copper toxicity to marine biota and understanding fundamental differences in species-sensitivity will require, not just an understanding of water quality parameters and copper-cell binding, but also further knowledge of cellular detoxification mechanisms. PMID:18639348

Levy, Jacqueline L; Angel, Brad M; Stauber, Jennifer L; Poon, Wing L; Simpson, Stuart L; Cheng, Shuk Han; Jolley, Dianne F

2008-06-08

322

Electromagnetic impact welding of copper-to-copper sheets  

Microsoft Academic Search

Copper (Cu) has some properties, similar to aluminium (Al), like high thermal conductivity, high thermal expansion coefficient,\\u000a relatively low melting point, brittleness at elevated temperatures and less viscosity of molten metal. These properties make\\u000a the welding of Cu and Cu alloys difficult as compared to welding of carbon steels. The present study investigates the feasibility\\u000a of electromagnetic impact welding of

Sachin Dnyandeo Kore; P. P. Date; S. V. Kulkarni; Satendra Kumar; Dolly Rani; M. R. Kulkarni; S. V. Desai; R. K. Rajawat; K. V. Nagesh; D. P. Chakravarty

2010-01-01

323

Laser shock compression of copper and copper-aluminum alloys  

SciTech Connect

Copper and copper aluminum (2 and 6 wt% Al) with orientations [0 0 1] and [1 3 4] were subjected to high intensity laser shocks (energy levels of 40-300 J; energy densities of 15-70 MJ/m2 and durations below 10 ns). In situ X-ray diffraction and VISAR wave profile measurements were used to study the response of the lattice to the shock. Recovered samples were characterized by transmission electron microscopy in order to study the defects within the lattice. The results are rationalized in terms of a criterion in which slip and twinning are considered as competing mechanisms. The slip-twinning transition is determined quantitatively and predicted as a function of orientation, temperature, and stacking fault energy (determined by the Al content of the alloy). A constitutive description is applied to the two orientations and differing compositions, incorporating both slip and twinning in terms of orientation, stacking fault energy, temperature, and strain rate. The threshold stress is calculated, considering the effect of shock heating. The constitutive description provides calculated thresholds in pure copper: 18 GPa for [0 0 1] and 25 GPa for [1 3 4]. The experimentally determined threshold twinning stress for pure copper in the [0 0 1] orientation is 25 GPa, whereas the one for the [1 3 4] orientation is between 40 and 60 GPa. The predictions are in agreement with experiments. It also provides thresholds for the Cu-Al alloys. The growth of voids in incipient spalling is modeled by dislocation loop emission from the void surface. The first dislocation-based void growth mechanism, proposed by Lubarda et al. [Acta Mat 2004; 52: 1397] is reviewed and extended to three dimensions. It has a generality rendering it applicable to a broad range of strain rates.

Schneider, Matthew S. [University of California, San Diego; Kad, Bimal [University of California, San Diego; Kalantar, Daniel H. [Lawrence Livermore National Laboratory (LLNL); Remington, Bruce A. [Lawrence Livermore National Laboratory (LLNL); Kenik, Edward A [ORNL; Jarmakani, H. [University of California, San Diego; Myers, Marc A. [University of California, San Diego

2005-01-01

324

Copper voids improvement for the copper dual damascene interconnection process  

Microsoft Academic Search

The mechanism of copper (Cu) voids formation from electro-chemical plating (ECP) followed by Cu chemical mechanical polishing (CMP) are studied in Cu dual-damascene interconnection. The formation of Cu voids at metal lines is the main problem that causes not only the failure of via-induced metal-island corrosion but also yield loss. The galvanic theory and Cu lifting mechanism are proposed to

T. C. Wang; Y. L. Wang; T. E. Hsieh; S. C. Chang; Y. L. Cheng

2008-01-01

325

Metallic Copper as an Antimicrobial Surface?  

PubMed Central

Bacteria, yeasts, and viruses are rapidly killed on metallic copper surfaces, and the term “contact killing” has been coined for this process. While the phenomenon was already known in ancient times, it is currently receiving renewed attention. This is due to the potential use of copper as an antibacterial material in health care settings. Contact killing was observed to take place at a rate of at least 7 to 8 logs per hour, and no live microorganisms were generally recovered from copper surfaces after prolonged incubation. The antimicrobial activity of copper and copper alloys is now well established, and copper has recently been registered at the U.S. Environmental Protection Agency as the first solid antimicrobial material. In several clinical studies, copper has been evaluated for use on touch surfaces, such as door handles, bathroom fixtures, or bed rails, in attempts to curb nosocomial infections. In connection to these new applications of copper, it is important to understand the mechanism of contact killing since it may bear on central issues, such as the possibility of the emergence and spread of resistant organisms, cleaning procedures, and questions of material and object engineering. Recent work has shed light on mechanistic aspects of contact killing. These findings will be reviewed here and juxtaposed with the toxicity mechanisms of ionic copper. The merit of copper as a hygienic material in hospitals and related settings will also be discussed.

Grass, Gregor; Rensing, Christopher; Solioz, Marc

2011-01-01

326

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

PubMed

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

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

2013-02-16

327

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

PubMed

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

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

2011-03-01

328

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

PubMed Central

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

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

2011-01-01

329

Regeneration of a Solution for Electroless Copper Plating  

Microsoft Academic Search

The possibility of electrochemical regeneration of a solution for electroless copper plating by membrane electrolysis was studied. The conditions of anodic dissolution of copper in a spent solution for electroless copper plating, under which the concentration of copper ions increases at a rate exceeding by an order of magnitude that of their deposition in the course of electroless copper plating,

D. Yu. Turaev; S. S. Kruglikov

2005-01-01

330

Soldering of aluminium with copper  

Microsoft Academic Search

Soldering of aluminium with copper becomes more significant, because of relatively low process temperature of about 400–450°C. It is applied not only in electrotechnical industry, in joining Al–Cu conductors, but also in cooling and air-conditioning equipment and in solar construction of collectors (Winiowski A. Lutowanie twarde aluminium i jegostopów – nowe trendy technologiczne, Biuletyn Instytutu Spawalnictwa, nr 6\\/2000, Fontargen GmbH.

Zbigniew Mirski; Kazimierz Granat; Hubert Drzeniek; Tomasz Piwowarczyk; Tomasz Wojdat

2011-01-01

331

Electric heating of copper conductors  

NASA Astrophysics Data System (ADS)

After a critical discussion of the contemporary state of the art a new differential equation describing electric heating of a conductor in quiet air has been derived and its solution is given. It is assumed that the heating is only caused by a constant value current passing through the conductor. The solution found is in good agreement with the experimental data in the range of temperatures to which copper conductors are subjected in electrical engineering applications.

Nasilowski, Jan

1984-02-01

332

Recovery of copper powders from leach solutions containing copper by means of ammonia, sulphur dioxide and acetonitrile  

Microsoft Academic Search

In this study, copper was precipitated as sulphites to produce copper powders from its impure solutions. Copper (I) sulphate solutions were prepared by utilizing these sulphites, and copper powders were produced by thermal disproportionation. The research was carried out in four steps: In the first step, the ore was dissolved with sulphuric acid. In the second step, the copper in

Sabri Çolak; Turan Çalban; Murat Ye?ilyurt; Demet Sergili; Zafer Ekinci

2003-01-01

333

Copper nitrilotriacetate: a potent therapeutic agent in the treatment of a genetic disorder of copper metabolism1  

Microsoft Academic Search

Copper nitrilotriacetate (NTA) was evaluated for its ability to ameliorate effects of the recessive mutant gene crinkled (cr) in mice. Copper-NTA was superior to copper sulfate in increasing postnatal survival and body copper content of offspring of dams supplemented during pregnancy and lactation. Feeding of NTA alone during these periods had no effect on survival. Postnatal supplementation with copper did

Carl L. Keen; Paul Saltman; Lucille S. Hurley

334

Electron scattering at copper surfaces  

NASA Astrophysics Data System (ADS)

As interconnects are scaled to smaller dimensions, the resistivity of the copper lines increases above the bulk resistivity due to a phenomena known as the size effect. Three components are known to contribute to the size effect: surface roughness, grain boundary scattering, and surface scattering. Of these, surface roughness and grain boundary scattering have been researched previously, and methods to minimize the resistivity increase due to these mechanisms have been proposed. The focus of this thesis research was to address the issue of surface scattering, which is the least understood component of the size effect. In particular, little is known about the materials and surface structure which lead to completely specular scattering (i.e. no increase in resistivity for thin layers). This research has built on the reported observation of partial specular scattering in both gold and silver films. The most promising layers have been shown to be single crystals. These single crystal films have the added advantage of simplifying the resistivity characterization, as there is no grain boundary component to the resistivity. Thus, particular focus was spent on determining the growth conditions required to produce high quality single crystal copper layers. Epitaxial copper layers were grown on single crystal magnesium oxide substrates with (001)Cu||(001)MgO with [001]Cu ||[001]MgO for samples grown at a substrate temperature T s of 100°C or less. The lattice mismatch between copper and MgO is 14.29%, which is resolved by 7x7 copper unit cells occupying 6x6 MgO cells. The highest crystalline quality was found for those layers grown at Ts = 100°C, while the layers grown at Ts = 40°C demonstrated the smoothest surface and lowest buried interface roughness. Surface morphology was studied through the use of in-situ scanning tunneling microscopy (STM). From these characterizations, the epitaxial copper surfaces have a self-affine surface structure, with a scaling exponent alpha of 0.82+/-0.03, independent of annealing. The mound width increased from 31+/-8 to 39+/-6 nm for increasing layer thickness, d, of 24 and 120 nm, respectively. The heights of the as-deposited mounds were nearly constant, independent of film thickness. In-situ annealing at Ta = 200 and 300°C results in thermodynamically driven mass transport that minimized the surface step density. This resulted in mounds with a larger mound radius and smaller root mean square roughness alpha. The effect was most pronounced on the thinnest layer, d = 24 nm, with the mound radius increasing from 31+/-8 to 70+/-20 nm, and sigma decreasing from 1.3+/-0.1 to 0.74+/-0.08 nm, for the as-deposited and 300°C annealed layers, respectively. Thus annealing resulted in a reduction in the mound aspect ratio when compared to the as-deposited layers. In the best case, terrace widths were increased from 1.5 to 6.3 nm, for the 24-nm-thick as-deposited and 300°C annealed layer, respectively. These terrace widths correspond to terraces which consist of 6 to 25 atoms per step. Further annealing at higher temperatures resulted in rough, partially discontinuous layers, attributed to oxidation of the copper-substrate interface as well as thermodynamically driven copper islanding in order to reduce the interfacial area between the copper and magnesium oxide. Electron transport experiments have shown that resistivity is highly dependent on the crystalline quality of the copper layers. Single crystal copper layers have resistivities that are a minimum of four times smaller than the polycrystalline layers, which is due to the absence of grain boundaries, which act as additional scattering centers. As-deposited copper layers resulted in completely diffuse scattering, which was attributed to the short length scales of atomically smooth terraces. Annealing resulted in layers which were smoother, but all layers exhibited completely diffuse surface scattering with a specularity parameter of p = 0. Low temperature and in-situ electron transport measurements were used in order to determine whether oxidation

Purswani, Jaya Murli

335

Effect of tarnish on copper release.  

PubMed

The rate of copper loss from bright and tarnished collars from Copper T Model TCu 380A IUDs has been investigated in amino acid solutions of pH 5.5 and 7.4 and in serum. In all three media, the tarnished collars quickly became bright and lost copper at the same rate as the initially bright collars. The single exception was when a high ratio of copper surface to serum was used. Under those conditions the tarnished collars initially became bright but after two days a black precipitate appeared on both the initially bright and tarnished collars and weight loss ceased. When a higher ratio of serum to copper surface was used, the pattern was one of continuing loss although at a lower rate than in the amino acid solutions. It is concluded that tarnish does not compromise the oxidation and dissolution of copper even in serum. Serum is considered a surrogate for uterine fluid. PMID:1756626

Tsong, Y Y; Nash, H A

1991-10-01

336

Risks and benefits of copper in light of new insights of copper homeostasis.  

PubMed

Copper is an essential micronutrient involved in a variety of biological processes indispensable to sustain life. At the same time, it can be toxic when present in excess, the most noticeable chronic effect being liver damage. Potent, efficient regulatory mechanisms control copper absorption in the digestive tract and copper biliary excretion; absorption ranges between 12 and 60% in humans, depending on Cu intake, presence of other factors in the diet that may promote or inhibit its absorption and on the copper status of the individual. Current evidence suggests that copper deficiency may be more prevalent than previously thought, while copper toxicity is uncommon under customary daily life conditions. Menkes syndrome and Wilson disease are genetic conditions associated with severe copper deficiency and severe copper toxicity, respectively. Effects of milder degrees of copper deficiency and excess copper exposure are not well described, mainly due to lack of sensitive and specific indicators; serum copper concentration and ceruloplasmin are the most frequently used indicators, but they only detect rather intense changes of copper status. Of the many proteins assessed as potential markers of copper status the chaperone of Zn-Cu superoxide dismutase (CCS1) has yielded promising results; data on its performance under different conditions are needed to confirm its use as an indicator of early copper deficiency. Defining copper requirements and upper safe limits of consumption (UL) is a complex process since there are adverse health consequences from both copper deficiency and copper excess (U shape curve). The regulatory framework for risk assessment of essential trace elements introduced by the International Programme on Chemical Safety (IPCS) has proposed a homeostatic model to determine the Adequate Range of Oral Intake (AROI) of essential trace elements; the nadir of the resulting U shape curve serves to define the AROI. At this range of intake physiological mechanisms allow for normal homeostasis and basically, there are no detectable adverse effects. At present, Recommended Dietary Intakes (DRIs) and Adequate Intakes (AIs) are used to recommend copper intakes at different ages and life situations. Evidence obtained in humans and non-human primates presented here suggest that current copper UL should be re evaluated. Developing the scientific basis for a copper UL and evaluating the relevance of copper deficiency globally are future key challenges for copper researchers. PMID:21342755

de Romaña, Daniel López; Olivares, Manuel; Uauy, Ricardo; Araya, Magdalena

2011-02-20

337

Copper status in the rat is affected by modes of copper delivery.  

PubMed

The purpose of this study was to determine whether the interaction between fructose and copper status can be affected by the mode of copper administration. Male Sprague-Dawley rats (n = 94) were fed from weaning diets that contained 0.65-0.85 mg copper/kg diet for 42 d. The experimental design of the study was a 2 x 2 x 3 analysis of variance: two types of carbohydrate (fructose, corn starch), two modes of copper delivery (orally or subcutaneously) and three different extrinsic copper levels (0, 1.5 or 3 mg/kg diet or 0, 11.25 or 22.5 micrograms Cu/d by injection). In the rats fed fructose, direct indicators of copper status such as plasma copper and tissue superoxide dismutase activity were increased to a much greater extent when copper was supplied subcutaneously rather than orally as part of the diet. In the starch-fed rats the effect of the mode of copper delivery on the levels of these indices was usually not significantly different. As a result, the feeding of fructose as compared to starch produced lower levels of direct indicators of copper status when copper was supplied in the diet but not subcutaneously. It appears that ingestion of fructose as compared to starch increases the requirement for copper and that the mode of copper administration that circumvents the gastrointestinal tract attenuates the fructose-copper interaction. Thus, the fructose-copper interaction occurs either during intestinal digestion and absorption, hepatic uptake of copper via the portal blood or its hepatic utilization. PMID:2921645

Koh, E T; Reiser, S; Fields, M; Scholfield, D J

1989-03-01

338

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

Microsoft Academic Search

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%

D. Salam; M. El-Fadel

2008-01-01

339

Properties of copper and copper alloys at cryogenic temperatures. Final report  

Microsoft Academic Search

The mechanical and physical properties at cryogenic temperatures for selected coppers and copper alloys have been compiled, reviewed, and analyzed. Tables, figures, and regression equations are included. The materials are: the oxygen-free coppers (C10100-C10700), beryllium coppers (C17000-C17510), and the phosphor bronzes (C50500-C52400). The temperature range for the property data is from 4 to 295 K. Mechanical properties include tensile, toughness,

N. J. Simon; E. S. Drexler; R. P. Reed

1992-01-01

340

Preparation of shape-controlled copper oxide powders from copper-containing solution  

Microsoft Academic Search

Shape-controlled copper oxides have been recovered from copper-containing waste etchant by neutralization with alkali hydroxide. Large amounts of copper-containing waste etchant composed of copper chloride, hydrochloric acid and water are generated from the printed circuit board (PCB) industry. In an environmental and economic point of view, the retrieval of the valuable natural resource from waste is important. In the recycling

Younghee Ko Kim; Doh-Hyung Riu; Soo-Ryong Kim; Byung-Ik Kim

2002-01-01

341

Myeloneuropathy due to copper deficiency: clinical and MRI findings after copper supplementation  

Microsoft Academic Search

Acquired copper deficiency constitutes an under-recognised cause of myelopathy. Aim of the study was to describe the clinical\\u000a and imaging features at admission and after copper supplementation of a patient with acquired copper deficiency myeloneuropathy.\\u000a A 73-year-old woman presented with anaemia and signs of posterior column dysfunction. Somatosensory evoked potentials showed\\u000a impaired central pathway conduction. Serum copper and caeruloplasmin levels

Laura Bolamperti; Maurizio A. Leone; Alessandro Stecco; Monica Reggiani; Mario Pirisi; Alessandro Carriero; Francesco Monaco

2009-01-01

342

Effects of copper and copper fungicide soil residues on Phytophthora infestans  

Microsoft Academic Search

Summary  Analysis of soils from plots in which potatoes had been sprayed with copper fungicides showed that the amount of water extractable\\u000a copper remained fairly constant at 5 to 7 ppm, while the content of replaceable copper ranged from 20 to 92 ppm.\\u000a \\u000a Copper was found to impair the germination ofP. infestans sporangia to a greater extent than that of zoospores.

Simeon S. Leach

1966-01-01

343

Incorporation of the red copper nitrosocyanin binding loop into blue copper azurin  

Microsoft Academic Search

\\u000a Abstract  Loop-directed mutagenesis was applied to the blue copper protein azurin to replace its copper binding loop with that from\\u000a the red copper protein nitrosocyanin. A ten amino acid long loop that provides three of the four copper ligands from nitrosocyanin\\u000a was incorporated into azurin to make a variant called NC-azurin. The chimeric protein displayed a red color, and UV–vis absorption

Steven M. BerryErika; Erika L. Bladholm; Elise J. Mostad; Audrey R. Schenewerk

2011-01-01

344

Copper Does Not Alter the Intracellular Distribution of ATP7B, a Copper-Transporting ATPase  

Microsoft Academic Search

Wilson's disease is a genetic disorder characterized by the accumulation of copper in the body due to a defect of biliary copper excretion. However, the mechanism of biliary copper excretion has not been fully clarified. We examined the effect of copper on the intracellular localization of the Wilson disease gene product (ATP7B) and green fluorescent protein (GFP)-tagged ATP7B in a

Masaru Harada; Shotaro Sakisaka; Takumi Kawaguchi; Rina Kimura; Eitaro Taniguchi; Hironori Koga; Shinichiro Hanada; Shinji Baba; Koh Furuta; Ryukichi Kumashiro; Toshihiro Sugiyama; Michio Sata

2000-01-01

345

Wear resistance of copper EDM tool electrode electroformed from copper sulfate baths and pyrophosphate baths  

Microsoft Academic Search

Electroforming copper from the copper sulfate baths or the pyrophosphate baths is one of commonly used methods for manufacturing\\u000a electro-discharge machining (EDM) tool electrode, in particular for the fabrication of micro- and meso-scale tool electrodes\\u000a with complex cross-section, but few literature on the electrode-wear performance of electroformed copper electrode has been\\u000a available until today. To better select copper tool electrode

Ping Mei Ming; Di Zhu; Yong Bin Zeng; Yang Yang Hu

2010-01-01

346

Relationship between copper exposure duration, tissue copper concentration, and rainbow trout growth  

Microsoft Academic Search

Rainbow trout fry were exposed in soft water to sublethal concentrations of copper for 60 days under controlled laboratory conditions. At 20-day intervals, fish were sampled for weight, length, and whole-body copper and metallothionein concentrations. Exposures to waterborne copper concentrations as low as 4.6 ?g 1?1 resulted in significantly reduced growth and significantly elevated whole-body copper concentrations after 20 days.

J. C. A. Marr; J. Lipton; D. Cacela; J. A. Hansen; H. L. Bergman; J. S. Meyer; C. Hogstrand

1996-01-01

347

Effects of copper speciation on aquatic ecosystems  

SciTech Connect

The kinds and quantities of copper species present in influent and effluent waters were determined in samples collected from power stations located adjacent to marine, estuarine, and freshwater ecosystems. Copper concentration and speciation differed with the site, season, and mode of operation of the station. Under normal operating conditions, the differences between influent and effluent waters were generally small and, at those sites where measurements of chemical form were taken, most of the copper was in bound (complexed) species. During startup of water circulation through cooling systems and during changeover from an open- to a closed-cycle operation, however, copper was high in concentration. The size, chemical form, and duration of the copper pulse released during startup and changeover differed with factors such as the interval between shutdown and startup, preconditioning of the condenser tubing, and hydrodynamic conditions. The effect of copper speciation on copper toxicity was evaluated. The responses to different chemical forms of copper differed with species and life stage. Some primary producers and early life stages of higher trophic organisms are sensitive to low levels of labile copper. Sublethal effects of copper on bluegills were assessed in populations living in the intake and discharge zones of a station adjacent to a fresh-water impoundment. These populations showed structural abnormalities and reduced reproductive capacity. Tissue analyses showed elevated copper concentrations in the livers. Liver metalloproteins were separated and quantified. The results indicated that metal detoxification systems in the bluegills were saturated and copper was present in some metalloprotein pools in levels that may result in impairment of metabolic functions.

Harrison, F.L.

1983-03-01

348

Electroless copper metallisation of titanium nitride  

Microsoft Academic Search

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

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

1995-01-01

349

Measuring bioavailable copper using anodic stripping voltammetry  

Microsoft Academic Search

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,

Emily Deaver; John H. Rodgers

1996-01-01

350

Pressure leaching las cruces copper ore  

NASA Astrophysics Data System (ADS)

A hydrometallurgical process was developed for treating the Las Cruces massive sulfide-ore deposit located near Seville, Spain. A two-stage countercurrent leach process, consisting of an atmospheric leach and a pressure leach, was developed to effectively leach copper from the copper-bearing minerals and to generate a solution suitable for the subsequent solvent-extraction and copper-electrowinning operations. The results of batch and continuous miniplant tests are presented.

Berezowsky, R. M.; Xue, T.; Collins, M. J.; Makwana, M.; Barton-Jones, I.; Southgate, M.; Maclean, J. K.

1999-12-01

351

Polypyrrole\\/polythiophene coating for copper protection  

Microsoft Academic Search

The electrochemical synthesis of polythiophene (PTh) has been investigated on copper electrode, in LiClO4 containing acetonitrile medium (ACN–LiClO4). It was shown that a corrosion protective PTh film cannot be obtained on copper surface, by direct electro oxidation of thiophene, because the surface could not be passivated sufficiently and copper dissolution continued in the monomer oxidation potential region. This prevented the

T. Tüken; B. Yaz?c?; M. Erbil

2005-01-01

352

A Bright Future for copper electrowinning  

Microsoft Academic Search

Over the past 40 years, the copper mining industry has undergone a dramatic shift toward hydrometallurgical extraction of\\u000a copper at the mine site. This has increased the importance of recovering high-purity copper by electrowinning. High-purity\\u000a cathode production was achieved by implementing numerous technologies including superior lead-alloy anodes, improved cathode\\u000a handling and\\/or stainless steel blanks, better electrolyte control, and advanced tankhouse

Michael Moats; Michael Free

2007-01-01

353

Earth's copper resources estimated from tectonic diffusion of porphyry copper deposits  

Microsoft Academic Search

Improved estimates of global mineral endowments are relevantto issues ranging from strategic planning to global geochemicalcycling. We have used a time-space model for the tectonic migrationof porphyry copper deposits vertically through the crust tocalculate Earth's endowment of copper in mineral deposits. Themodel relies only on knowledge of numbers and ages of porphyrycopper deposits, Earth's most widespread and important sourceof copper,

Stephen E. Kesler; Bruce H. Wilkinson

2008-01-01

354

Copper specifically regulates intracellular phosphorylation of the Wilson's disease protein, a human copper-transporting ATPase.  

PubMed

Copper is a trace element essential for normal cell homeostasis. The major physiological role of copper is to serve as a cofactor to a number of key metabolic enzymes. In humans, genetic defects of copper distribution, such as Wilson's disease, lead to severe pathologies, including neurodegeneration, liver lesions, and behavior abnormalities. Here, we demonstrate that, in addition to its role as a cofactor, copper can regulate important post-translational events such as protein phosphorylation. Specifically, in human cells copper modulates phosphorylation of a key copper transporter, the Wilson's disease protein (WNDP). Copper-induced phosphorylation of WNDP is rapid, specific, and reversible and correlates with the intracellular location of this copper transporter. WNDP is found to have at least two phosphorylation sites, a basal phosphorylation site and a site modified in response to increased copper concentration. Comparative analysis of WNDP, the WNDP pineal isoform, and WNDP C-terminal truncation mutants revealed that the basal phosphorylation site is located in the C-terminal Ser(796)-Tyr(1384) region of WNDP. The copper-induced phosphorylation appears to require the presence of the functional N-terminal domain of this protein. The novel physiological role of copper as a modulator of protein phosphorylation could be central to understanding how copper transport is regulated in mammalian cells. PMID:11470780

Vanderwerf, S M; Cooper, M J; Stetsenko, I V; Lutsenko, S

2001-07-26

355

Copper Specifically Regulates Intracellular Phosphorylation of the Wilson's Disease Protein, a Human Copper-transporting ATPase  

Microsoft Academic Search

Copper is a trace element essential for normal cell homeostasis. The major physiological role of copper is to serve as a cofactor to a number of key metabolic en- zymes. In humans, genetic defects of copper distribu- tion, such as Wilson's disease, lead to severe pathologies, including neurodegeneration, liver lesions, and behavior abnormalities. Here, we demonstrate that, in addition to

Scott M. Vanderwerf; Matthew J. Cooper; Inna V. Stetsenko; Svetlana Lutsenko

2001-01-01

356

An electronmicroscopic study on copper precipitation by copper-resistant yeast cells  

Microsoft Academic Search

Summary By electronmicroscopic observation of ultrathin sections, it was revealed that sulfide of copper was precipitated richly in the cell wall of copper-resistant yeast cells cultured in a copper-containing medium. The ratio Cu:S of the precipitation seems to range from about 1.8 to 1.

Joji Ashida; Noboru Higashi; Tadatoshi Kikuchi

1963-01-01

357

Identification of copper ions in aqueous and vitreous of eyes containing copper and iron foreign bodies  

Microsoft Academic Search

The reliability of aqueous analysis by the atomic absorption spectrophotometer for copper ion content in samples from eyes containing intravitreal pure copper particles was investigated. It was demonstrated that values of copper ions rose well above the normal in the aqueous as well as in the vitreous of such eyes. The standard deviations of the mean values were generally high.

Y Yassur; H Zauberman; M Zidon

1975-01-01

358

Extractive separation of copper and nickel from copper bleed stream by solvent extraction route  

Microsoft Academic Search

Bleed stream from electro refining step of copper smelter was processed to recover the metals as high value products such as copper and nickel powders or salts. The process consists of partial decopperisation of the bleed stream followed by crystallization of a mixed salt of copper and nickel sulphate, leaching of the mixed salt, removal of iron, solvent extraction for

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

2008-01-01

359

Quantitative chemical analysis on paper: Microdetermination of copper and a mixture of copper and silver  

Microsoft Academic Search

Summary A method has been suggested for the determination of small amounts of copper and of mixtures of copper and silver using filter paper impregnated with silver chloride and sodium carbonate. The method depends on competition between copper and silver ions to form complexes with cyanide added to the paper. The area of the spot produced by conversion of AgCl

K. Koev

1965-01-01

360

Deposition of Diamond Films on Copper Substrate  

NASA Astrophysics Data System (ADS)

The direct deposition of diamond films on copper substrate has been suffered from adhesion problems due to the mismatch of the thermal expansion coefficients of diamond and copper. In this paper, nuclei with valuable density were directly introduced through a submicron diamond powder layer. The diamond grits partially were buried in the copper substrate leading to better adhesion. Another method with nickel intermediate layer for enhancing the adhesion was studied here in detail. It was suggested that Cu-Ni eutectic between the copper substrate and Ni interlayer might contribute to the adhesion improvement. The quality of the diamond films deposited with nickel interlayer was investigated by scanning electron microscopy and Raman spectroscopy.

Ma, Zhi-bin; Wu, Qin-chong; Shu, Xing-sheng; Wang, Jian-hua; Wang, Chuan-xin; Li, Xiang-feng

2000-04-01

361

Material flows generated by pyromet copper smelting  

USGS Publications Warehouse

Copper production through smelting generates large volumes of material flows. As copper contained in ore becomes copper contained in concentrate to be fed into the smelting process, it leaves behind an altered landscape, sometimes mine waste, and always mill tailings. Copper concentrate, fluxing materials, fuels, oxygen, recyclables, scrap and water are inputs to the process. Dust (recycled), gases - containing carbon dioxide (CO2) (dissipated) and sulfur dioxide (SO2) (mostly collected, transformed and sold) and slag (discarded or sold) - are among the significant process outputs. This article reports estimates of the flows of these input/output materials for a particular set of smelters studied in some countries.

Goonan, T. G.

2005-01-01

362

Unraveling the Amycolatopsis tucumanensis copper-resistome.  

PubMed

Heavy metal pollution is widespread causing serious ecological problems in many parts of the world; especially in developing countries where a budget for remediation technology is not affordable. Therefore, screening for microbes with high accumulation capacities and studying their stable resistance characteristics is advisable to define cost-effective any remediation strategies. Herein, the copper-resistome of the novel copper-resistant strain Amycolatopsis tucumanensis was studied using several approaches. Two dimensional gel electrophoresis revealed that proteins of the central metabolism, energy production, transcriptional regulators, two-component system, antioxidants and protective metabolites increased their abundance upon copper-stress conditions. Transcriptome analysis revealed that in presence of copper, superoxide dismutase, alkyl hydroperoxide reductase and mycothiol reductase genes were markedly induced in expression. The oxidative damage of protein and lipid from A. tucumanensis was negligible compared with that observed in the copper-sensitive strain Amycolatopsis eurytherma. Thus, we provide evidence that A. tucumamensis shows a high adaptation towards copper, the sum of which is proposed as the copper-resistome. This adaptation allows the strain to accumulate copper and survive this stress; besides, it constitutes the first report in which the copper-resistome of a strain of the genus Amycolatopsis with bioremediation potential has been evaluated. PMID:22585085

Dávila Costa, José Sebastián; Kothe, Erika; Abate, Carlos Mauricio; Amoroso, María Julia

2012-05-15

363

Thermo-Optical Characterization of Cadmium Selenide/Zinc Sulfide (CdSe/ZnS) Quantum Dots Embedded in Biocompatible Materials.  

PubMed

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

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

2013-09-01

364

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)

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.

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

2009-08-01

365

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

PubMed

The structure of tetrasodium penta-deca-molybdenum nona-deca-selenide, Na3.88Mo15Se19, is isotypic with the In3+x Mo15Se19 compounds [Grüttner et al. (1979 ?). Acta Cryst. B35, 285-292]. It is characterized by two cluster units, Mo6Se (i) 8Se (a) 6 and Mo9Se (i) 11Se (a) 6 (where i represents inner and a apical atoms), that are present in a 1:1 ratio. The cluster units are centered at Wyckoff positions 2b and 2c and have point-group symmetry -3 and -6, respectively. The clusters are inter-connected through additional Mo-Se bonds. In the title compound, the Na(+) cations replace the trivalent as well as the monovalent indium atoms present in In3.9Mo15Se19. One Mo, one Se and one Na atom are situated on mirror planes, and two other Se atoms and one Na atom [occupancy 0.628?(14)] are situated on threefold rotation axes. The crystal studied was twinned by merohedry with refined components of 0.4216?(12) and 0.5784?(12). PMID:24098158

Salloum, Diala; Gougeon, Patrick; Gall, Philippe

2013-09-25

366

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

PubMed Central

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

Salloum, Diala; Gougeon, Patrick; Gall, Philippe

2013-01-01

367

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

Microsoft Academic Search

Quaternary selenides Sn2Pb5Bi4Se13 and Sn8.65Pb0.35Bi4Se15 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 Sn2Pb5Bi4Se13: a=14.001(6)Å, b=4.234(2)Å, c=23.471(8)Å, V=1376.2(1)Å3, R1\\/wR2=0.0584\\/0.1477, and GOF=1.023; Sn8.65Pb0.35Bi4Se15: a=13.872(3)Å, b=4.2021(8) (4)Å, c=26.855(5)Å, V=1557.1(5)Å3, R1\\/wR2=0.0506\\/0.1227, and GOF=1.425. These compounds exhibit tropochemical cell-twinning

Kuei-Bo Chen; Chi-Shen Lee

2009-01-01

368

Effect of Physicochemical Form on Copper Availability to Aquatic Organisms.  

National Technical Information Service (NTIS)

Copper concentration and speciation were determined in influent and effluent waters collected from eight power stations that used copper alloys in their cooling systems. Quantities of copper associated with particles, colloids, and organic and inorganic l...

F. L. Harrison

1983-01-01

369

21 CFR 862.1190 - Copper test system.  

Code of Federal Regulations, 2010 CFR

...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...

2009-04-01

370

21 CFR 862.1190 - Copper test system.  

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

371

Alternative Methods for Copper Recovery from Dump Leach Liquors.  

National Technical Information Service (NTIS)

The Bureau of Mines conducted large-scale laboratory copper ore leaching tests to enable improving copper recovery from large dump-leaching operations. This was done by comparing leaching progress when copper was recovered from recycled leach liquor eithe...

B. W. Madsen R. D. Groves

1981-01-01

372

Microstructure effects in CVD copper  

NASA Astrophysics Data System (ADS)

Computer chip manufacturers are beginning to implement copper as interconnect material in high-performance microprocessor metallization architectures. Replacing currently used aluminum metallization with its copper based counterpart will result in performance gain due to the low resistivity of copper (1.67muO·cm) which generates a reduction in (resistance x capacitance) signal delay. Futhermore, enhancements in stress and electromigration resistance by up to three orders of magnitude are expected from replacing aluminum with copper. Copper deposited by chemical vapor deposition has the proven ability to yield complete fill of aggressive via and trench structures at high deposition rates. At the same time, ultrathin Cu seed layers can be controlled grown by chemical vapor deposition (CVD) for use as activation layer in electrolytic plating (EP) applications. Additionally, integration studies using single and two-level damascene interconnect structures CVD Cu showed that excellent yield can be obtained. However, before CVD Cu can be incorporated into manufacturing process flows, several key reliability issues have to be addressed and resolved. At present, electroplating has the advantage of enhanced electromigration performance compared to CVD copper. It is therefore necessary to demonstrate the systematic ability to tailor the microstructure of CVD copper with the goal of enhanced electromigration and stress migration performance through the successful formation of (111) textured Cu with bamboo type microstructure. In the present work, the evolution of as-deposited Cu resistivity, grain size, texture, and surface roughness were systematically analyzed as a function of film thickness for an optimized CVD Cu process. In particular, investigations of the influence of substrate type and surface pretreatment on texture and grain size showed that: (a) Cu grows (111) textured on PVD TiN, if (002) Ti matrix is present, and on inorganic CVD TiN, regardless of the underlying matrix, and (b) hydrogen plasma pre-deposition surface treatment enhances texture "transfer" from the linear into the CVD Cu. Experimental observations of the evolution of as-deposited resistivity and texture were compared with the predictions from theoretical models, leading to a thorough understanding of key structural and morphological features of the CVD Cu process. In addition, grain texture and size evolution were examined in fine Cu lines as a function of post deposition annealing and feature size. The impact of liner material was assessed in terms of its effects on as-deposited and post-annealed grain size and texture. In particular, thermal treatment was shown to induce an increase in average grain size by up to 100%, but did not seem to exhibit any effect on Cu texture. Furthermore, the results indicated that appropriate processing methodology can be optimized for the CVD growth of bamboo-structured Cu (111) fine lines with enhanced electromigration resistance.

Manger, Dirk Karl

373

Behavior of Copper Impurity in ZnSe  

Microsoft Academic Search

The luminescence and diffusion behavior of copper impurity in ZnSe has been studied by the substoichiometric isotope dilution analysis and photoluminescence measurements. The copper-green emission is prominent in higher Cu-doped crystals, while the copper-red emission is prominent in lower copper concentration ZnSe. Copper acts as the killer center against the near-band edge blue emission. The characteristics of the recombination centers

Masafumi Yamaguchi; Toshio Shigematsu

1978-01-01

374

A Copper (II) Aspirinate Project for the General Chemistry Laboratory  

ERIC Educational Resources Information Center

|Describes an experiment that involves the synthesis of copper (II) aspirinate and the analysis of copper content in the product using electrogravimetric, spectrophotometric, and titrimetric methods. (MLH)|

Dudek, Emily

1977-01-01

375

Laboratory evolution of copper tolerant yeast strains  

PubMed Central

Background Yeast strains endowed with robustness towards copper and/or enriched in intracellular Cu might find application in biotechnology processes, among others in the production of functional foods. Moreover, they can contribute to the study of human diseases related to impairments of copper metabolism. In this study, we investigated the molecular and physiological factors that confer copper tolerance to strains of baker's yeasts. Results We characterized the effects elicited in natural strains of Candida humilis and Saccharomyces cerevisiae by the exposure to copper in the culture broth. We observed that, whereas the growth of Saccharomyces cells was inhibited already at low Cu concentration, C. humilis was naturally robust and tolerated up to 1 g · L-1 CuSO4 in the medium. This resistant strain accumulated over 7 mg of Cu per gram of biomass and escaped severe oxidative stress thanks to high constitutive levels of superoxide dismutase and catalase. Both yeasts were then "evolved" to obtain hyper-resistant cells able to proliferate in high copper medium. While in S. cerevisiae the evolution of robustness towards Cu was paralleled by the increase of antioxidative enzymes, these same activities decreased in evolved hyper-resistant Candida cells. We also characterized in some detail changes in the profile of copper binding proteins, that appeared to be modified by evolution but, again, in a different way in the two yeasts. Conclusions Following evolution, both Candida and Saccharomyces cells were able to proliferate up to 2.5 g · L-1 CuSO4 and to accumulate high amounts of intracellular copper. The comparison of yeasts differing in their robustness, allowed highlighting physiological and molecular determinants of natural and acquired copper tolerance. We observed that different mechanisms contribute to confer metal tolerance: the control of copper uptake, changes in the levels of enzymes involved in oxidative stress response and changes in the copper-binding proteome. However, copper elicits different physiological and molecular reactions in yeasts with different backgrounds.

2012-01-01

376

Geomorphology of the lower Copper River, Alaska  

USGS Publications Warehouse

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.

Brabets, Timothy P.

1997-01-01

377

Geomorphology of the lower Copper River, Alaska  

USGS Publications Warehouse

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.

Brabets, T. P.

1996-01-01

378

Increased blood and urine copper after residential exposure to copper naphthenate  

SciTech Connect

Despite widespread industrial use of copper naphthenate, there are no reports of the relationship of copper naphthenate and copper absorption in humans or animals. We report a family of three individuals who lived in a home where copper naphthenate was sprayed on the inner foundation. Subsequently, these individuals developed non-specific complaints. In two of these individuals, serum copper levels were elevated when first measured months after copper naphthenate was sprayed in the home. A gradual decline over several years in urine and serum copper levels was observed in the individual who maintained follow-up. It is not known if symptoms reflected exposure to naphthenate, the solvent vehicle, volatilized copper, or the stress of exposure to a malodorous compound perceived as toxic. Exposure to copper naphthenate may be another cause of an elevated serum and urine copper level but the interpretation of these levels as normal' or toxic' requires additional study for clarification. This report suggests the need for further study of the absorption and relative toxicity of copper naphthenate.

Bluhm, R.E.; Welch, L.; Branch, R.A. (Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (United States))

1992-01-01

379

Initiation of electroless nickel plating on copper, palladium-activated copper, gold, and platinum  

SciTech Connect

The catalytic activity of copper, palladium-activated copper, gold, and platinum for electro-oxidation of hypophosphite and electroless nickel plating was investigated in an ammoniacal solution of pH 8.8 at 50/sup 0/C by potential measurements and linear sweep voltammetry from -0.3 to -0.92V vs. SCE. Early stages of nickel plating on copper-palladium substrates were studied by scanning electron microscopy in conjunction with EDAX. It was found that palladium-activated copper and gold were catalytically active in the entire range of potentials examined; copper was active below -0.6 platinum was not active at all. Small amounts of electrolytically deposited nickel considerably increased the electro-oxidation rate of hypophosphite on copper, gold, and palladium. TEM examinations showed that activation of copper in a PdCl/sub 2//HCl solution resulted in the deposition of palladium in the form of separate patches. Electroless nickel deposition on copper substrates with separate palladium spots took place on copper and palladium independently of each other. The deposition on palladium was faster than that on copper. It was concluded that the activation of copper substrates around palladium spots occurred solely through a spontaneous potential shift, induced by electro-oxidation of hypophosphite on the palladium spots. It was suggested that small amounts of one metal synergistically enhanced the catalytic activity of the other metals.

Flis, J.; Duquette, D.J.

1984-02-01

380

Mechanical Separation of Metallic Copper from Polymer-Insulated Copper Wire  

NASA Astrophysics Data System (ADS)

It is very important to recycling of polymer-insulated copper wire to remove copper from the wire without any contamination. A rolling machine and a blender were used to separate and recover the copper wires from a polymer coated cable. In the experiment using a rolling machine, the recovery of copper was improved by an increase in the number of rolling times and by lowering the cable temperature. All of the copper was recovered from a cable of 115 K in temperature. In the other experiment using a blender, the weight of the recovery of copper was increased by shortening the cable length and by increasing the rotary speed of the blender and the treating time. All the copper in a cut cable of 3mm long was recovered from a cable.

Yokoyama, Seiji; Takeuchi, Sakae; Hisyamudin Bin Muhd Nor, Nik

2011-01-01

381

Mechanical Separation of Metallic Copper from Polymer-Insulated Copper Wire  

SciTech Connect

It is very important to recycling of polymer-insulated copper wire to remove copper from the wire without any contamination. A rolling machine and a blender were used to separate and recover the copper wires from a polymer coated cable. In the experiment using a rolling machine, the recovery of copper was improved by an increase in the number of rolling times and by lowering the cable temperature. All of the copper was recovered from a cable of 115 K in temperature. In the other experiment using a blender, the weight of the recovery of copper was increased by shortening the cable length and by increasing the rotary speed of the blender and the treating time. All the copper in a cut cable of 3mm long was recovered from a cable.

Yokoyama, Seiji [Department of Mechanical Engineering, Toyohashi University of Technology, (1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi, 441-8105, JAPAN) (Japan); Takeuchi, Sakae [Graduate School of Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi, 441-8105 (Japan); Hisyamudin Bin Muhd Nor, Nik [Department of Mechanical and Manufacturing Engineering, University Tun Hussein Onn Malaysia (Now, Graduate School of Toyohashi University of Technology) (Malaysia)

2011-01-17

382

Copper complexes as grease additives  

SciTech Connect

In order to improve the tribological properties of lubricating greases containing copper powder, it is recommended that various organic substances with donor properties should be added in amounts up to 0.2%. Greases containing metal powders have a number of disadvantages that limit their application. Therefore, it is more logical to prepare complexes of metals with organic ligands and then introduce them into the grease in small amounts. We have carried out a study of the influence of various complex compounds on the tribological properties of greases.

Ishchuk, Yu. L.; Mel`nik, Z.P.; Barykina, S.S. [and others

1994-11-01

383

Excitonic superconductivity in copper oxides  

SciTech Connect

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

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

1988-01-01

384

Copper vapor laser precision processing  

NASA Astrophysics Data System (ADS)

Copper vapor laser (CVL) was designed on the basis master oscillator (MO) - spatial filter - amplifier (AMP) system which is placed in thermostable volume. Processing material is moved by means of CNC system GPM-AP-400 with +/- 5 micrometers accuracy. Several cutting parameters are considered which define the quality and productivity of vaporization cutting: efficiency, cutwidth, height of upper and lower burr, roughness, laser and heat affected zones. Estimates are made for some metals with thickness 0.02 - 0.3 mm and cutwidth 0.01 - 0.03 mm. The examples of workpieces produced by CVL are presented.

Nikonchuk, Michail O.

1991-05-01

385

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...

386

Preparation of copper powder by glycerol process  

Microsoft Academic Search

A simple, least energy intensive, efficient, low temperature chemical process for the production of copper powder of narrow size distribution is described. It involves reduction of copper salts by glycerol under atmospheric conditions at a temperature below 240°C. The powders produced by this process have been characterized by X-ray diffraction, chemical composition, BET surface area analysis and scanning electron microscopy.

Amit Sinha; B. P Sharma

2002-01-01

387

Common Sense Copper and RF Guns  

SciTech Connect

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

Mulhollan, G.

2005-01-18

388

Copper Mining and Environmental Costs in Dominica  

Microsoft Academic Search

A proposal from an international mining company to establish a copper mining operation in the Caribbean island of Dominica could be highly favourable, given the potential for financial benefits associated with such a project. On the downside, such projects are often associated with environmental damage. The area targeted for this copper mine was a rainforest in the north-eastern portion of

Emaline L. Harris-Charles; Carlisle A. Pemberton

2007-01-01

389

Copper chloride cathode for a secondary battery  

Microsoft Academic Search

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

Ratnakumar V. Bugga; Salvador Distefano; Ganesan Nagasubramanian; Clyde P. Bankston

1990-01-01

390

Copper laser diagnostics and kinetics support  

SciTech Connect

In the effort MSNW participated with the LINL copper-Vapor Laser Program by providing a useful plasma diagnostic for interpretation of Copper-vapor laser kinetics. MSNW developed and delivered a pulsed interferometric diagnostic package to LLNL. Moreover MSNW provided personal services at the request and direction of LLL in the implementation of the diagnostic and interpretation of the data.

Not Available

1981-12-01

391

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...

392

Is the Western diet adequate in copper?  

PubMed

Copper has been known to be essential for health for more than three quarters of a century. Myriad experiments with animals reveal that the cardiovascular, musculoskeletal and nervous systems are most sensitive to deficiency. Copper in the Western diet has been decreasing at least since the 1930s; half of the adult population consumes less than the amount recommended in the European Communities and the United Kingdom. At least one fourth of adults consume less than the estimated average requirement published for the United States and Canada. Hundreds of people have been reported in journals about medicine and neurology rather than nutrition to have impaired copper nutriture based on the criteria of low copper concentrations and low activities of enzymes dependent on copper in various fluids and tissues. In contrast, only 46 people have participated in depletion/repletion experiments needed to define requirements. Almost 1000 people have benefited from supplements containing copper in controlled trials. People deficient in copper are being identified increasingly; it is unknown if unusually high requirements or unusually low diets are causal. Alzheimer's disease, ischemic heart disease and osteoporosis are the most likely human illnesses from low copper intakes. PMID:21982501

Klevay, Leslie M

2011-10-05

393

A discharge heated copper vapor laser  

Microsoft Academic Search

A simple, reliable copper vapor laser is described with vapor produced by discharge heating. Average output power of 1.3 W has resulted at 6.8 kHz and a specific energy of 39 ?J\\/cm3. Copper vapor density as high as3 times 10^{16}cm-3was achieved.

R. S. Anderson; L. Springer; B. G. Bricks; T. W. Karras

1975-01-01

394

Planktonic microbial community responses to added copper  

Microsoft Academic Search

It is generally agreed that autotrophic organisms and especially phytoplanktonic species can be harmed by copper through its effect on photosystem. However, the impact of copper on other components of the pelagic food web, such as the microbial loop (autotrophic and heterotrophic picoplankton, pigmented and non-pigmented flagellates and ciliates) has received little attention. Indoor experiments were conducted to evaluate the

Anne-Hélène Le Jeune; Marie Charpin; Denis Sargos; Jean-François Lenain; Véronique Deluchat; Nadine Ngayila; Michel Baudu; Christian Amblard

2007-01-01

395

Defect analysis of copper ball bonding  

Microsoft Academic Search

Copper ball bonding has gained more and more popularity compared to gold ball bonding due to its better electrical conductivity, better thermal conductivity, higher mechanical strength, lower cost and better reliability and so on. However copper wire has two well-known disadvantages, one is its greater hardness, the other is being easy to be oxidized when forming FAB (free air ball).

Huabin Chu; Jun Hu; Ling Jin; Yingliang Jie

2008-01-01

396

Copper metallization of stainless steels. Final report  

SciTech Connect

Stainless steel plates were vacuum metallized with pure copper films 0.004 inch thick. Prior to metallization the surfaces were cleaned with EPA-approved detergents. A thin layer of chromium was sputtered for improved adhesion followed by sputtering of the copper. Results showed excellent adhesion of the sputtered films to the substrates.

Rosenblum, B.Z.

1994-09-01

397

Additive monitoring and interactions during copper electroprocessing  

NASA Astrophysics Data System (ADS)

The electrochemical deposition of copper has been a major focus of research for decades. Renewed interest in copper electroplating is not limited to the copper producers but is also a major concern of semiconductor manufacturers. The focus on copper electrochemistry by the semiconductor manufacturers has increased since IBM's announcement in 1997 that copper will be used for metallization in high speed/power semiconductors [1--3]. The desire to use copper instead of aluminum is simply a reflection on copper's superior conductivity (lower RC time constants) and resistance to electromigration (generally proportional to the melting point). This dissertation is the compilation of the research into analytical techniques for monitoring surface-active additives in common sulfuric acid/copper sulfate plating baths. Chronopotentiometric, DC and AC voltammetry were the major analytical techniques used in this research. Several interactions between the additives will also be presented along with their apparent decline in activity. The decline in activity is well known in the industry and is also detected by these methods as presented in chapters 4 and 5. Finally, a systemic approach for monitoring the additive Galactosal, which is commonly used in electrowinning, will be outlined. The monitoring system proposed herein would have to be adjusted for each electrowinning facility because each has a unique chemistry and cell configuration.

Collins, Dale Wade

398

Fluidized-bed copper oxide process  

SciTech Connect

The fluidized-bed copper oxide process was developed to simultaneously remove sulfur dioxide and nitrogen oxide contaminants from the flue gas of coal-fired utility boilers. This dry and regenerable process uses a copper oxide sorbent in a fluidized-bed reactor. Contaminants are removed without generating waste material. (VC)

Shah, P.P.; Takahashi, G.S.; Leshock, D.G.

1991-10-14

399

Electrolytic Method for obtaining Bright Copper Surfaces  

Microsoft Academic Search

IT is possible to polish a copper surface electro-lytically by making it the anode in an aqueous solution of orthophosphoric acid at high current density (minunum 25 amp.\\/dm.2). This mode of polishing is particularly suitable for metallographic examinations, and has been used for the examination of copper deposits in presence of various colloids.

P. A. Jacquet

1935-01-01

400

Copper uptake by the water hyacinth  

Microsoft Academic Search

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

Terrence A. Lee; James K. Hardy

1987-01-01

401

Stress in copper films for interconnects  

Microsoft Academic Search

As the scaling down of integrated circuits progresses the demands for the interconnect material will reach a point where aluminium and its alloys can not be used any longer. Copper has the potential to meet future requirements, especially with its low electrical resistivity and high resistance against electromigration. Developing deposition processes for copper it is important to investigate the properties

S. Riedel; J. Rober; S. E. Schulz; T. Gessner

1997-01-01

402

Electroless Copper Plating Using Dimethylamine Borane.  

National Technical Information Service (NTIS)

Electroless copper plating from baths containing dimentylamine borane is discussed. An ammoniacal alkaline bath was developed that produces electroless copper deposits at 2.3 micrometers/hr on a variety of substrates; the dposits contain less than 0.1 per...

F. Pearlstein R. F. Weightman

1973-01-01

403

Initial study on copper CMP slurry chemistries  

Microsoft Academic Search

Chemical mechanical polishing (CMP) of copper has been investigated with suspended silica and alumina abrasives using various slurry chemistries. The characteristics of these chemistries were studied by electrochemical d.c. polarization and a.c. impedance measurements. Problems and directions related to the formulation of copper CMP slurries are discussed.

Ronald Carpio; Janos Farkas; Rahul Jairath

1995-01-01

404

The contemporary copper cycle of Asia  

Microsoft Academic Search

A regional stock and flow model for an industrial metal was developed based on the substance-flow framework. Using this model, the contemporary copper cycle of the Asian region was constructed by aggregating country-level production and import and export data for different stages of the copper cycle. The reliability and availability of data were assessed both qualitatively and quantitatively. Asia as

Amit Kapur; Marlen Bertram; Sabrina Spatari; Kensuke Fuse; Thomas E. Graedel

2003-01-01

405

Electrodialytic remediation of copper mine tailings  

Microsoft Academic Search

Mining activities in Chile have generated large amounts of solid waste, which have been deposited in mine tailing impoundments. These impoundments cause concern to the communities due to dam failures or natural leaching to groundwater and rivers.This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. The results show that electric current could remove copper

Henrik K. Hansen; Adrián Rojo; Lisbeth M. Ottosen

2005-01-01

406

Copper Metallization for High Performance Silicon Technology  

NASA Astrophysics Data System (ADS)

The increasingly rapid transition of the electronics industry to high-density, high-performance multifunctional microprocessor Si technology has precipitated migration to new materials alternatives that can satisfy stringent requirements. One of the recent innovations has been the substitution of copper for the standard aluminum-copper metal wiring in order to decrease resistance and tailor RC delay losses in the various hierarchies of the wiring network. This has been accomplished and the product shipped only since the fall of 1998, after more than a decade of intensive development. Critical fabrication innovations include the development of an electroplating process for the copper network, dual-damascence chem-mech polishing (CMP), and effective liner material for copper diffusion barrier and adhesion promotion. The present copper technology provides improved current-carrying capability by higher resistance to electromigration, no device contamination by copper migration, and the performance enhancement analytically predicted. This success of the shift to copper will accelerate the industry movement to finer features and more complex interconnect structures with sufficient device density and connectivity to integrate full systems on chips. The next innovation will be the introduction of low-dielectric constant material that, in combination with copper, will create added excitement as the industry learns how to utilize this new capability.

Rosenberg, R.; Edelstein, D. C.; Hu, C.-K.; Rodbell, K. P.

2000-08-01

407

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 ...

408

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

SciTech Connect

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

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

409

A Bright Future for copper electrowinning  

NASA Astrophysics Data System (ADS)

Over the past 40 years, the copper mining industry has undergone a dramatic shift toward hydrometallurgical extraction of copper at the mine site. This has increased the importance of recovering high-purity copper by electrowinning. High-purity cathode production was achieved by implementing numerous technologies including superior lead-alloy anodes, improved cathode handling and/or stainless steel blanks, better electrolyte control, and advanced tankhouse automation. In the future, it is projected that tankhouses will produce high-quality copper at lower costs using technologies that could include dimensionally stable anodes, alternative anode reactions, innovative cell designs, novel electrolyte circulation systems, and more. This paper reviews existing commercial copper electrowinning technologies and discusses advances that need to be made to implement future technologies.

Moats, Michael; Free, Michael

2007-10-01

410

Reactions of ?-dichlorobis(? 3-allyl)palladium(II) with bis(1 -H-benzo-triazolyl-methyl) selenide: Formation of unexpected polymeric structure with dormant Se donor site. Applications of the polymeric Pd-complexes in Heck coupling  

Microsoft Academic Search

Bis(1-H-benzotriazolylmethyl)selenide (L) has been synthesized by reacting Se2? generated in situ with 1-(chloromethyl)-1H-benzotriazole. Proton, C-13 and Se-77 NMR spectra of L are characteristic. ?-Dichlorobis(?3-allyl)palladium(II) reacts with L resulting in polymeric complexes which give single crystals of stoichiometry [Pd(?3-C3H5)(L)]·ClO4\\/PF6·CH3CN (1\\/2). The single crystal X-ray diffraction analyses of these polymeric species reveal that they have chain type of structures, and anions through

Dipanwita Das; Monika Singh; Ajai K. Singh

2009-01-01

411

Update on copper oxide superconductors  

SciTech Connect

The early high-{Tc} superconductors Ba{sub 2}YCu{sub 3}O{sub 7} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} remain the most studied for their potential application. The number and variety of new copper oxide superconductors discovered since 1986 is remarkable. Although physicists like to take credit for the superconductivity revolution, it is really a revolution in new materials. New materials of continually increasing complexity have driven the field forward since its beginning. It is no accident that the chemically simplest copper oxide superconductors were discovered first. Higher {Tc} values have been caused by the rapid growth in general knowledge in the material community of the empirical factors necessary for the occurrence of high-{Tc} superconductivity. The growth is based on improving chemical understanding of previous discoveries. The chemical understanding and complexity of cuprate superconductors continue to increase. The appearance in 1993 of mercury-based materials has further raised {Tc} values.

Cava, R.J. [AT and T Bell Labs., Murray Hill, NJ (United States)

1995-05-01

412

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

PubMed

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

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

2012-10-21

413

Bacterial stimulation of copper phytoaccumulation by bioaugmentation with rhizosphere bacteria.  

PubMed

Copper contaminated areas pose environmental health risk to living organisms. Remediation processes are thus required for both crop production and industrial activities. This study employed bioaugmentation with copper resistant bacteria to improve phytoremediation of vineyard soils and copper mining waste contaminated with high copper concentrations. Oatmeal plant (Avena sativa L.) was used for copper phytoextraction. Three copper resistant bacterial isolates from oatmeal rhizosphere (Pseudomonas putida A1; Stenotrophomonas maltophilia A2 and Acinetobacter calcoaceticus A6) were used for the stimulation of copper phytoextraction. Two long-term copper contaminated vineyard soils (Mollisol and Inceptisol) and copper mining waste from Southern Brazil were evaluated. Oatmeal plants substantially extracted copper from vineyard soils and copper mining waste. As much as 1549 mg of Cu kg?¹ dry mass was extracted from plants grown in Inceptisol soil. The vineyard Mollisol copper uptake (55 mg Cu kg?¹ of dry mass) in the shoots was significantly improved upon inoculation of oatmeal plants with isolate A2 (128 mg of Cu kg?¹ of shoot dry mass). Overall oatmeal plant biomass displayed higher potential of copper phytoextraction with inoculation of rhizosphere bacteria in vineyard soil to the extent that 404 and 327 g ha?¹ of copper removal were respectively observed in vineyard Mollisol bioaugmented with isolate A2 (S. maltophilia) and isolate A6 (A. calcoaceticus). Results suggest potential application of bacterial stimulation of phytoaccumulation of copper for biological removal of copper from contaminated areas. PMID:20937516

Andreazza, Robson; Okeke, Benedict C; Lambais, Márcio Rodrigues; Bortolon, Leandro; de Melo, George Wellington Bastos; Camargo, Flávio Anastácio de Oliveira

2010-11-01

414

Relapsing hypocupraemic myelopathy requiring high-dose oral copper replacement  

Microsoft Academic Search

Adult-onset copper deficiency with neurological manifestations is a newly recognised syndrome. Long-term oral copper replacement therapy has been the mainstay of treatment in the literature. A case of relapsing hypocupraemic myelopathy responsive to increased doses of copper replacement is reported. Standard doses of copper may not be sufficient for all patients.

C I Prodan; S S Bottomley; N R Holland; S E Lind

2006-01-01

415

Relapsing hypocupraemic myelopathy requiring high-dose oral copper replacement  

PubMed Central

Adult?onset copper deficiency with neurological manifestations is a newly recognised syndrome. Long?term oral copper replacement therapy has been the mainstay of treatment in the literature. A case of relapsing hypocupraemic myelopathy responsive to increased doses of copper replacement is reported. Standard doses of copper may not be sufficient for all patients.

Prodan, C I; Bottomley, S S; Holland, N R; Lind, S E

2006-01-01

416

???????????????????????????????????????????????????????? Performance Improvement of Copper Melting Furnace using Air Preheater  

Microsoft Academic Search

The aim of this research is to improve the performance of copper melting furnace using air preheater at a copper cable manufacturing factory. Before installation of the air preheater, the thermal efficiency of the copper furnace is approximately 47.11% where heat loss in the exhaust gas is nearly half of the energy input of copper melting furnace. After installation of

Tawatchai Sittisradoo; Sompong Putivisutisak

417

Determination of the Taste Threshold of Copper in Water  

Microsoft Academic Search

Copper effects on human health represent a relevant issue in modern nutrition. One of the difficulties in assessing the early, acute effects of copper ingested via drinking water is that the taste of copper may influence the response and the capacity to taste copper in different waters is unknown. The purpose of the study was to determine the taste threshold

I. Zacarias; Carmen G. Yáñez; Magdalena Araya; Chinwe Oraka; Manuel Olivares; Ricardo Uauy

2001-01-01

418

Bioinorganic Chemical Modeling of Dioxygen-Activating Copper Proteins.  

ERIC Educational Resources Information Center

|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…

Karlin, Kenneth D.; Gultneh, Yilma

1985-01-01

419

Bioinorganic Chemical Modeling of Dioxygen-Activating Copper Proteins.  

ERIC Educational Resources Information Center

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…

Karlin, Kenneth D.; Gultneh, Yilma

1985-01-01

420

Influence of complexing agents on texture formation of electrodeposited copper  

Microsoft Academic Search

Ethylenediaminetetraacetic acid (EDTA) and sodium citrate were used as complexing agents for copper coated on Ni–P substrate via the electrodeposited copper procedure. X-ray diffraction (XRD) has been used to examine the effect of complexing agents on the texture of copper films. The experimental results showed that copper films deposited without any additives have two different texture types, (111) and (110)

Bo Hong; Chuan-hai Jiang; Xin-jian Wang

2007-01-01

421

Investigations of the copper centers in proteins, phenanthrolines and polynucleotides  

Microsoft Academic Search

This work encompasses three different projects in three different copper systems with the underlying inorganic themes of bio-inorganic and photochemistry. The first project involved the mechanism of removal of copper from Rhus vernicifera tree laccase, a blue copper oxidase. Specifically, the selective removal of the type 2 copper was investigated. The mechanistic insights appear to be general in that under

Michele Katherine Eggleston

1996-01-01

422

Antibacterial Effects of Solid Copper on Waterborne Bacteria  

Microsoft Academic Search

Objectives\\/Goals I came across an article about people in India who are throwing copper and silver coins into their rivers. They believe copper and silver coins will be able to disinfect their polluted water systems. I designed an experiment to test the antibacterial effects of copper in water. After researching, I hypothesized that solid copper might have a moderate effect

Anna N. Shuster

423

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...

424

The Intec Copper Process: A Detailed Environmental Analysis  

Microsoft Academic Search

The Intec Copper Process is an environmentally advantageous hydrometallurgical process for the production of high purity copper and associated precious metals from copper sulphide concentrates. The process uses a mixed chloride-bromide lixiviant in an elegant cyclic circuit to leach the copper into solution, rejecting the iron as stable hematite rather than as unstable jarosite. After purification of the pregnant liquor,

D Sammut; N J Welham

425

Normal macrophage function in copper deficient mice  

SciTech Connect

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.

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

1986-03-01

426

Redox control of copper homeostasis in cyanobacteria.  

PubMed

Copper is essential for all living organisms but is toxic when present in excess. Therefore organisms have developed homeostatic mechanism to tightly regulate its cellular concentration. In a recent study we have shown that CopRS two-component system is essential for copper resistance in the cyanobacterium Synechocystis sp PCC 6803. This two-component regulates expression of a heavy-metal RND type copper efflux system (encoded by copBAC) as well as its own expression (in the copMRS operon) in response to an excess of copper in the media. We have also observed that both operons are induced under condition that reduces the photosynthetic electron flow and this induction depends on the presence of the copper-protein, plastocyanin. These findings, together with CopS localization to the thylakoid membrane and its periplasmic domain being able to bind copper directly, suggest that CopS could be involved in copper detection in both the periplasm and the thylakoid lumen. PMID:23073008

López-Maury, Luis; Giner-Lamia, Joaquín; Florencio, Francisco J

2012-10-16

427

Copper toxicosis in a Boer goat.  

PubMed

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

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

2012-11-02

428

Machining and mechanical engraving of copper thermal-sprayed coatings  

NASA Astrophysics Data System (ADS)

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.

Schroeder, M.

1998-09-01

429

Planktonic microbial community responses to added copper.  

PubMed

It is generally agreed that autotrophic organisms and especially phytoplanktonic species can be harmed by copper through its effect on photosystem. However, the impact of copper on other components of the pelagic food web, such as the microbial loop (autotrophic and heterotrophic picoplankton, pigmented and non-pigmented flagellates and ciliates) has received little attention. Indoor experiments were conducted to evaluate the direct and indirect effects of copper, supplied in the range of concentrations used to control cyanobacteria growth in ponds, on non-targeted organisms of natural microbial loop communities sampled in spring and summer. Two copper concentrations were tested (80microgL(-1) and 160microgL(-1) final concentrations), set, respectively, below and above the ligand binding capacity of the water samples. Both caused a significant decrease in the biomass and diversity of pigmented organisms (picophytoplankton and pigmented flagellates). Conversely, the heterotrophic bacterioplankton and the heterotrophic flagellates did not seem to be directly affected by either copper treatment in terms of biomass or diversity, according to the descriptor chosen. The ciliate biomass was significantly reduced with increasing copper concentrations, but differences in sensitivity appeared between spring and summer communities. Potential mixotrophic and nanoplanktorivorous ciliates appeared to be more sensitive to copper treatments than bacterivorous ciliates, suggesting a stronger direct and (or) indirect effect of copper on the former. Copper sulphate treatments had a significant restructuring effect on the microbial loop communities, resulting in a dominance of heterotrophic bacterioplankton among microbial microorganisms 27 days after the beginning of the treatment. The spring microbial communities exhibited a greater sensitivity than the summer communities with respect to their initial compositions. PMID:17582517

Le Jeune, Anne-Hélène; Charpin, Marie; Sargos, Denis; Lenain, Jean-François; Deluchat, Véronique; Ngayila, Nadine; Baudu, Michel; Amblard, Christian

2007-05-05

430

Isolation of copper-binding proteins from activated sludge culture.  

PubMed

Six copper-binding microbial proteins were isolated from activated sludge cultures grown on media containing copper at various concentrations. Molecular weights among isolated proteins were ranged from 1.3k to 1 74k dalton. Isolated proteins were compared for their copper binding capabilities. Proteins isolated from cultures grown in the presence of copper in the growth media exhibited higher copper binding capabilities than those isolated from the culture grown in the absence of copper. The highest metal uptake of 61.23 (mol copper/mol protein) was observed by a protein isolated from a culture grown with copper at a concentration of 0.25 mM. This isolated protein (CBP2) had a molecular weight of 24k dalton. Other protein exhibited copper binding capability of 4.8-32.5 (mol copper/mol protein). PMID:11548018

Fukushi, K; Kato, S; Antsuki, T; Omura, T

2001-01-01

431

Myeloneuropathy due to copper deficiency: clinical and MRI findings after copper supplementation.  

PubMed

Acquired copper deficiency constitutes an under-recognised cause of myelopathy. Aim of the study was to describe the clinical and imaging features at admission and after copper supplementation of a patient with acquired copper deficiency myeloneuropathy. A 73-year-old woman presented with anaemia and signs of posterior column dysfunction. Somatosensory evoked potentials showed impaired central pathway conduction. Serum copper and caeruloplasmin levels were low. Nerve conduction assessment revealed axonal polyneuropathy. Spinal magnetic resonance imaging (MRI) showed posterior column hyperintensity. Diffusion tensor imaging disclosed decreased fractional anisotropy (FA) corresponding to the hyperintensity. Copper supplementation normalised the haematological picture, whereas vibratory sensitivity was only slightly improved. Control MRI revealed a slight hyperintensity at C1-C2 level; FA values normalised. In conclusion, in acquired copper-deficiency-associated myelopathy, correction of blood and MRI alterations precedes that of neurological manifestations, which may remain suboptimal. PMID:19768378

Bolamperti, Laura; Leone, Maurizio A; Stecco, Alessandro; Reggiani, Monica; Pirisi, Mario; Carriero, Alessandro; Monaco, Francesco

2009-09-19

432

Effects of organic matters coming from Chinese tea on soluble copper release from copper teapot.  

PubMed

The morphology and elemental composition of the corrosion products of copper teapot's inner-surface were characterized by the scanning electron microscopy and energy dispersive X-ray surface analysis (SEM/EDS), X-ray powder diffraction (XRD) and X-ray photon spectroscopy (XPS) analysis. It was revealed that Cu, Fe, Ca, P, Si and Al were the main elements of corrosion by-products, and the alpha-SiO(2), Cu(2)O and CaCO(3) as the main mineral components on the inner-surface of copper teapot. The effects of organic matters coming from Chinese tea on soluble copper release from copper teapots in tap water were also investigated. The results showed that the doses of organic matter (as TOC), temperate and stagnation time have significant effects on the concentration of soluble copper released from copper teapots in tap water. PMID:17904199

Ni, Lixiao; Li, Shiyin

2007-09-27

433

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

NASA Astrophysics Data System (ADS)

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 the partially exchanged (Cu+ Na+) ??-alumina as a solid electrolyte for temperatures between 870 and 1300 K. The activities of copper and nickel in the solid solution at these temperatures exhibited positive deviations from Raoult's law. The activity coefficients of copper and nickel at infinite dilution at 973 K were estimated to be 5.55 and 3.71, respectively. Furthermore, the free energies, enthalpies and entropies of mixing were derived from EMF data.

Oishi, Toshio; Tagawa, Shinya; Tanegashima, Soichiro

2005-02-01

434

Patterning conductive copper by nanotransfer printing  

NASA Astrophysics Data System (ADS)

We describe a method for patterning conductive copper over large areas by nanotransfer printing (nTP). This technique is purely additive and yields feature sizes in the 1-500 ?m range. Unlike gold patterns printed in a similar manner, oligomers from poly(dimethylsiloxane) (PDMS) stamps used in nTP permeate through the entire thickness of printed copper resulting in nonconductive patterns. Hot leaching the PDMS stamps in toluene prior to printing removes residual oligomers; printing with pretreated stamps reproducibly yields conductive copper patterns with an average resistivity of 31 ??-cm.

Felmet, Kimberly; Loo, Yueh-Lin; Sun, Yangming

2004-10-01

435

Tandemly duplicated upstream control sequences mediate copper-induced transcription of the Saccharomyces cerevisiae copper-metallothionein gene.  

PubMed Central

Transcription of the Saccharomyces cerevisiae copper-metallothionein gene, CUP1, inducible by copper. By analyzing deletion and fusion mutants in the CUP1 5'-flanking region, we identified two closely related, tandemly arranged copper regulatory elements. A synthetic version of one of these elements conferred efficient copper induction on a heterologous promoter when present in two tandem copies. Images

Thiele, D J; Hamer, D H

1986-01-01

436

Penta-zirconium copper tribismuth  

PubMed Central

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.

Balinska, Agnieszka; Tarasiuk, Ivan; Pavlyuk, Volodymyr

2013-01-01

437

Electrowinning of Copper from Copper (I) Electrolytes. 3: Diffusion Coefficients and Rates of Electron Transfer in Copper (I) Electrolytes.  

National Technical Information Service (NTIS)

The object of this work was to measure diffusion coefficients and Tafel parameters in practical systems closely related to those employed in the CLEAR, Dextec or Parker processes and to compare values with the conventional copper (II) electrolytes. In thi...

D. M. Muir

1982-01-01

438

Synthesis and structural analysis of copper(II) cysteine complexes  

Microsoft Academic Search

This report describes the synthesis and structural analysis of stable copper(II) cysteine complexes. Pale pink copper(II) cysteine complexes were synthesized in mole ratios of 1:2, 1:4, and 1:6 of copper(II):cysteine in ethanol. Infrared spectroscopy and X-ray absorption spectroscopy confirmed that copper(II) binding occurred via the thiol ligand of cysteine. XANES analysis showed that the oxidation state of copper remained as

Kenneth M. Dokken; Jason G. Parsons; John McClure; Jorge L. Gardea-Torresdey

2009-01-01

439

Serum copper and zinc levels and copper\\/zinc ratio in patients with breast cancer  

Microsoft Academic Search

Serum copper, zinc levels, and the Cu\\/Zn ratio were evaluated in 31 patients with breast cancer and 35 healthy controls. Copper\\u000a and zinc were determined by atomic absorbtion spectrophotometry. The mean serum copper level and the mean Cu\\/Zn ratio in patients\\u000a with breast cancer were significantly higher than the control group (pp<0.001). In addition, the mean serum zinc level in

Idris Yücel; Fikret Arpaci; Ahmet Özet; Bülent Döner; Turan Karayilano?lu; Ahmet Sayar; Önder Berk

1994-01-01

440

Copper-matrix molybdenum particle composites made from copper coated molybdenum powder  

Microsoft Academic Search

Copper-matrix molybdenum particle composites containing 33 ~73 wt.% Mo were fabricated by hot pressing copper coated molybdenum\\u000a powder. For comparison, corresponding composites fabricated by hot pressing a mixture of copper and molybdenum powders were\\u000a also made. The former method gave composites of lower porosity, higher hardness, higher compressive yield strength, lower\\u000a coefficient of thermal expansion, lower electrical resistivity and higher

Pay Yih; D. D. L. Chung

1995-01-01

441

Purification of human copper, zinc superoxide dismutase by copper chelate affinity chromatography  

SciTech Connect

Copper, zinc superoxide dismutase was isolated from human red blood cell hemolysate by DEAE-Sepharose and copper chelate affinity chromatography. Enzyme preparations had specific activities ranging from 3400 to 3800 U/mg and recoveries were approximately 60% of the enzyme activity in the lysate. Copper chelate affinity chromatography resulted in a purification factor of about 60-fold. The homogeneity of the superoxide dismutase preparation was analyzed by sodium dodecyl sulfate-gel electrophoresis, analytical gel filtration chromatography, and isoelectric focusing.

Weslake, R.J.; Chesney, S.L.; Petkau, A.; Friesen, A.D.

1986-05-15

442

Initiation of electroless nickel plating on copper, palladium-activated copper, gold, and platinum  

Microsoft Academic Search

The catalytic activity of copper, palladium-activated copper, gold, and platinum for electro-oxidation of hypophosphite and electroless nickel plating was investigated in an ammoniacal solution of pH 8.8 at 50°C by potential measurements and linear sweep voltammetry from -0.3 to -0.92V vs. SCE. Early stages of nickel plating on copper-palladium substrates were studied by scanning electron microscopy in conjunction with EDAX.

J. Flis; D. J. Duquette

1984-01-01

443

In-situ ellipsometric study of copper passivation by copper heptanoate through electrochemical oxidation  

Microsoft Academic Search

Inhibition of copper in a desearated sodium heptanoate solution (0.08M, pH 8.0) by electro-oxidation has been investigated. Rp measurements were carried out to compare inhibition efficiency using this original method with that based on other usual chemical oxidation methods. In-situ spectroscopic and kinetic ellipsometric measurements have been performed to study the passivation mechanism of copper. The inhibition of copper is

N. Stein; L. Johann; C. Rapin; J. M. Lecuire

1998-01-01

444

Selective electroless copper plating on silicon seeded by copper ion implantation  

Microsoft Academic Search

We report on the successful use of copper (self) ion implantation into silicon to seed the electroless plating of copper on silicon (100) surfaces. Copper ions were implanted into silicon to doses of 5 times 10(exp 14)-6.4 times 10(exp 16) ions\\\\sq cm using a metal vapour vacuum arc ion implanter at extraction voltages of 10 kV and 20 kV. A

S. Bhansali; D. K. Sood; R. B. Zmood

1994-01-01

445

Phase relationships of the quaternary systems MCr2Se4-MGa2Se4 (M = Mn, Fe, Co, Ni): New layered ZnIn2S4-III type selenides  

NASA Astrophysics Data System (ADS)

The phase relationships of the quaternary systems MCr2Se4-MGa2Se4 (M = Mn, Fe, Co, Ni) and MV2S4-MGa2S4 (M = Fe, Ni) and the ternary system NiS-Ga2S3 were studied by X-ray phase analyses with the aim to prepare new layered structure and spinel-type chalcides. The hitherto unknown selenides MnCr0.5Ga1.5Se4, FeCr0.5Ga1.5Se4, CoCr0.5Ga1.5Se4, and (Ni, Cr, Ga, ?)3Se4 (all ZnIn2S4-III type) were obtained and characterized by X-ray and FIR studies. No quaternary chalcides are formed in the systems MV2S4-MGa2S4 ternary NiGa2Se4 and CoGa2Se4 were likewise not obtained. Whereas the phase widths of the end-member phases are small (with the exception of ?'-Ga2S3 at 1000°C) because of the strong tetrahedral and octahedral site preferences of gallium and both chromium and vanadium, respectively, the quaternary selenides form solid solutions of the type MCr2-2xGa2xSe4 with x = 0.65-0.80 for M = Mn and Fe.

Siwert, H.; Lutz, H. D.

1987-08-01

446

Urinary Copper Elevation in a Mouse Model of Wilson's Disease Is a Regulated Process to Specifically Decrease the Hepatic Copper Load  

Microsoft Academic Search

Body copper homeostasis is regulated by the liver, which removes excess copper via bile. In Wilson's disease (WD), this function is disrupted due to inactivation of the copper transporter ATP7B resulting in hepatic copper overload. High urinary copper is a diagnostic feature of WD linked to liver malfunction; the mechanism behind urinary copper elevation is not fully understood. Using Positron

Lawrence W. Gray; Fangyu Peng; Shannon A. Molloy; Venkata S. Pendyala; Abigael Muchenditsi; Otto Muzik; Jaekwon Lee; Jack H. Kaplan; Svetlana Lutsenko

2012-01-01

447

Digitonin resistance of liver mitochondria isolated from copper-deficient and copper-loaded rats.  

PubMed

Liver mitochondria of copper-deficient and copper-loaded rats are with changed composition, ultrastructure and functions. The aim of the present work is to study the digitonin resistance of these mitochondria as an indicator for the changes in the membranes. Copper deficiency and copper loading are achieved by eliminating resp. by adding copper to the diet for four to six weeks. The copper content of the mitochondria in the control group of animals is 0.55 X 10(-9)M/mg protein. 0.20 X 10(-9) M/mg protein in the copper-deficient rats and 1.8 X 10(-9) M in the copper-loaded rats. Digitonin resistance is measured by the degree of increase in the activity of a matrix enzyme, malatedehydrogenase, upon destruction of the various mitochondrial membranes and to a different degree by ascending digitonin concentrations. The digitonin effect on the membranes is maximal for concentrations of 0.8 to 1.0 mg digitonin/mg protein. The digitonin resistance of the inner membranes increases in the case of copper deficiency, while coppor loading has the opposite effect on the resistance of the outer membranes. Moreover, coppor loading results in an increase in the general activity of the mitochondrial malatedehydrogenase as compared with the control mitochondria. PMID:1211189

Russanov, E; Kirkova, M

1975-01-01

448

Effect of stainless steel on corrosion behavior of copper in a copper-bearing intrauterine device.  

PubMed

Some copper-bearing intrauterine devices (Cu-IUDs) consist of pure copper and stainless steel. Corrosion of copper in the Cu-IUD was anticipated to be affected by galvanic action due to electrical contact between these two metals. Electrochemical measurements were carried out in physiological saline with or without indomethacin, which was introduced for bleeding control. In the copper/stainless steel couple, the open-circuit potential of stainless steel was found to play a decisive role. In most cases, when stainless steel was in the passive state and acted as the cathode, the contact accelerated copper corrosion. In addition, the area ratio of stainless steel to copper altered copper corrosion behavior. The larger the area of stainless steel, the greater the acceleration of copper corrosion. It was noted that the stainless steel surface might be activated due to improper handling of the IUD. In this case, copper became the cathode of the couple and its corrosion was suppressed. PMID:9820933

Xue, H; Xu, N; Zhang, C

1998-06-01

449

Copper(ii) and triphenylphosphine copper(i) ethylene glycol carboxylates: synthesis, characterisation and copper nanoparticle generation.  

PubMed

Ethylene glycol-functionalised copper(ii) carboxylates Cu[O2CCR2(OC2H4)nOCH3]2 (n = 0-3; R = H, Me) () have been prepared by the reaction of [Cu2(OAc)4·2H2O] with CH3O(C2H4O)nCR2CO2H (). Upon reduction of with triphenylphosphine, the corresponding tris(triphenylphosphine)copper(i) complexes were obtained, which could be converted to the bis(triphenylphosphine)copper(i) complexes by removal of one phosphine ligand. Based on IR spectroscopy and single crystal X-ray structure analysis the binding motif of the carboxylato group on the copper ion is discussed. DSC, TG and TG-MS experiments were performed to analyse the thermal decomposition mechanism of . Complex was used as a precursor for the generation of copper nanoparticles by thermal decomposition in hexadecylamine without the need of any further reactants. Depending on the precursor concentration, spherical copper nanoparticles with a mean diameter ranging from 10 to 85 nm as well as nanorods with a length of up to 1.3 ?m (aspect ratios ranging between 2 and 32) were obtained. Electron diffraction analysis of the rods suggested that they consist of five domains which are arranged around a fivefold rotational axis. PMID:24030202

Adner, David; Möckel, Stefan; Korb, Marcus; Buschbeck, Roy; Rüffer, Tobias; Schulze, Steffen; Mertens, Lutz; Hietschold, Michael; Mehring, Michael; Lang, Heinrich

2013-10-22

450

40 CFR 468.20 - Applicability; description of the beryllium copper forming subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the beryllium copper forming subcategory. 468...FORMING POINT SOURCE CATEGORY Beryllium Copper Forming Subcategory § 468...Applicability; description of the beryllium copper forming subcategory....

2010-07-01

451

40 CFR 468.20 - Applicability; description of the beryllium copper forming subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the beryllium copper forming subcategory. 468...FORMING POINT SOURCE CATEGORY Beryllium Copper Forming Subcategory § 468...Applicability; description of the beryllium copper forming subcategory....

2009-01-01

452

40 CFR 468.20 - Applicability; description of the beryllium copper forming subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the beryllium copper forming subcategory. 468...FORMING POINT SOURCE CATEGORY Beryllium Copper Forming Subcategory § 468...Applicability; description of the beryllium copper forming subcategory....

2013-07-01

453

40 CFR 468.20 - Applicability; description of the beryllium copper forming subcategory.  

Code of Federal Regulations, 2011 CFR

...Applicability; description of the beryllium copper forming subcategory. ...FORMING POINT SOURCE CATEGORY Beryllium Copper Forming Subcategory ...Applicability; description of the beryllium copper forming...

2011-07-01

454

Biliary excretion of copper in LEC rat after introduction of copper transporting P-type ATPase, ATP7B  

Microsoft Academic Search

Wilson's disease, an autosomal recessive disorder, is characterized by the excessive accumulation of hepatic copper that results from reduced biliary copper excretion and disturbed incorporation of copper into ceruloplasmin. The ATP7B gene, responsible for the disease, encodes a copper transporting P-type ATPase. We previously demonstrated the involvement of ATP7B in hepatic copper secretion into plasma after the introduction of ATP7B

Kunihiko Terada; Namiko Aiba; Xiao-Li Yang; Masatake Iida; Michio Nakai; Naoyuki Miura; Toshihiro Sugiyama

1999-01-01

455

Simulated small-scale pilot heap leaching of low-grade copper sulfide ore with selective extraction of copper  

Microsoft Academic Search

The bioleaching of low-grade copper sulfide ore and the selective extraction of copper were investigated. Lix984 dissolved in kerosene was used as extractant. The results show that it is possible to selectively leach copper from the ores by heap leaching. The copper concentration of leaching liquor after 250 d is 2.17 g\\/L, and the copper concentration is 0.27 g\\/L after

Wen-qing QIN; Yan-sheng ZHANG; Wei-zhong LI; Jun WANG

2008-01-01

456

Copper Vapor Lasers for Isotope Separation.  

National Technical Information Service (NTIS)

Copper vapor lasers for uranium isotope separation were investigated. The laser system is composed of an oscillator and an amplifier, the diameters of which are 28 and 50 mm, respectively. An inverter electric power supply which synchronizes the laser fre...

C. Yamanaka E. Fujiwara T. Naka T. Takeda T. Yamanaka

1986-01-01

457

Manufacturing Methods for Dispersion Strengthened Copper.  

National Technical Information Service (NTIS)

Oxide-strengthened copper forms were processed from powders prepared by spray drying, calcining, and selective hydrogen reduction. The powders were compacted, sintered, and hot consolidated. Two major problems were encountered in the preparation of consol...

N. E. Kopatz W. Scheithauer R. F. Cheney

1970-01-01

458

Atom chips on direct bonded copper substrates  

NASA Astrophysics Data System (ADS)

We present the use of direct bonded copper (DBC) for the straightforward fabrication of high power atom chips. Atom chips using DBC have several benefits: excellent copper/substrate adhesion, high purity, thick (>100 ?m) copper layers, high substrate thermal conductivity, high aspect ratio wires, the potential for rapid (<8 h) fabrication, and three-dimensional atom chip structures. Two mask options for DBC atom chip fabrication are presented, as well as two methods for etching wire patterns into the copper layer. A test chip, able to support 100 A of current for 2 s without failing, is used to determine the thermal impedance of the DBC. An assembly using two DBC atom chips is used to magnetically trap laser cooled 87Rb atoms. The wire aspect ratio that optimizes the magnetic field gradient as a function of power dissipation is determined to be 0.84:1 (height:width).

Squires, Matthew B.; Stickney, James A.; Carlson, Evan J.; Baker, Paul M.; Buchwald, Walter R.; Wentzell, Sandra; Miller, Steven M.

2011-02-01

459

Atom chips on direct bonded copper substrates.  

PubMed

We present the use of direct bonded copper (DBC) for the straightforward fabrication of high power atom chips. Atom chips using DBC have several benefits: excellent copper/substrate adhesion, high purity, thick (>100??m) copper layers, high substrate thermal conductivity, high aspect ratio wires, the potential for rapid (<8 h) fabrication, and three-dimensional atom chip structures. Two mask options for DBC atom chip fabrication are presented, as well as two methods for etching wire patterns into the copper layer. A test chip, able to support 100 A of current for 2 s without failing, is used to determine the thermal impedance of the DBC. An assembly using two DBC atom chips is used to magnetically trap laser cooled (87)Rb atoms. The wire aspect ratio that optimizes the magnetic field gradient as a function of power dissipation is determined to be 0.84:1 (height:width). PMID:21361567

Squires, Matthew B; Stickney, James A; Carlson, Evan J; Baker, Paul M; Buchwald, Walter R; Wentzell, Sandra; Miller, Steven M

2011-02-01

460

Environmental Consideration for Emerging Copper Winning Processes.  

National Technical Information Service (NTIS)

Fourteen processes for the production of copper were examined to evaluate their potential environmental impact, economics and energy requirements relative to reverberatory smelting as commonly practices in the U.S. Because of limitations in data available...

H. Dolezal M. Hayashi G. M. Potter J. Burckle

1982-01-01

461

Investigating Automotive Gear Lubricant Copper Corrosivity.  

National Technical Information Service (NTIS)

An investigation was initiated to identify relationships between copper strip ratings and organic acidity/alkalinity values for gear oils meeting both military and commercial factory-fill specifications. No correlation was found to exist between organic a...

J. V. Shimek M. E. LePera

1973-01-01

462

Process for manufacturing stranded copper wire  

US Patent & Trademark Office Database

Oxidation of stranded copper wire during high temperature coating with non-melt-fabricable tetrafluoroethylene polymer is substantially prevented by subjecting the wire to a nonoxidizing atmosphere during heating immediately prior to and during coating.

Ross; John A. (Wallingford, PA)

1981-11-10

463

Atom chips on direct bonded copper substrates  

SciTech Connect

We present the use of direct bonded copper (DBC) for the straightforward fabrication of high power atom chips. Atom chips using DBC have several benefits: excellent copper/substrate adhesion, high purity, thick (>100 {mu}m) copper layers, high substrate thermal conductivity, high aspect ratio wires, the potential for rapid (<8 h) fabrication, and three-dimensional atom chip structures. Two mask options for DBC atom chip fabrication are presented, as well as two methods for etching wire patterns into the copper layer. A test chip, able to support 100 A of current for 2 s without failing, is used to determine the thermal impedance of the DBC. An assembly using two DBC atom chips is used to magnetically trap laser cooled {sup 87}Rb atoms. The wire aspect ratio that optimizes the magnetic field gradient as a function of power dissipation is determined to be 0.84:1 (height:width).

Squires, Matthew B.; Stickney, James A.; Carlson, Evan J.; Baker, Paul M.; Buchwald, Walter R.; Wentzell, Sandra; Miller, Steven M. [Air Force Research Laboratory, Hanscom AFB, Massachusetts 01731 (United States)

2011-02-15

464

Copper-Nickel Cladding on Stainless Steel.  

National Technical Information Service (NTIS)

Copper-nickel cladding on conventional and super-austenitic stainless steel has proved effective in reducing maintenance (from biofouling, reapplication of anti-fouling coatings, and corrosion) for various small ferries, tankers, and ships in Europe and N...

D. A. Shifler

2005-01-01

465

Copper-Tungsten Composites Sprayed by HVOF  

NASA Astrophysics Data System (ADS)

Copper and copper-tungsten composite coatings were produced by high-velocity oxy-fuel spraying (HVOF). After initial optimization of the spraying parameters, coatings of various compositions were made and their structure, composition, mechanical, thermal, and electrical properties were characterized. The HVOF technique was able to produce rather dense coatings with minimal oxide content and relatively good mechanical and thermal properties compared to, for example, plasma-sprayed coatings; however, the achieved tungsten content was quite low.

Mat?jí?ek, Ji?í; Zahálka, František; Bensch, Jan; Chi, Weiguang; Sedlá?ek, Josef

2008-06-01

466

PROGRESS IN COPPER-BASED WAFER BONDING  

Microsoft Academic Search

This article discusses a method of wafer-to-wafer bonding using metallic copper as the bonding medium. This method is commonly known as thermo-compression bonding. Bonding process is described and characterization results are presented. Reliability issues related to voids formation in the bonded layer is discussed. A survey on progress of copper-based wafer bonding and its application for 3-D ICs is included.

Chuan Seng Tan

467

Copper transport and compartmentation in grape cells.  

PubMed

Copper-based fungicides have been widely used against several grapevine (Vitis vinifera L.) diseases since the late 1800s when the Bordeaux mixture was developed, but their intensive use has raised phytotoxicity concerns. In this study, physiological, biochemical and molecular approaches were combined to investigate the impacts of copper in grape cells and how it is transported and compartmented intracellularly. Copper reduced the growth and viability of grape cells (CSB, Cabernet Sauvignon Berry) in a dose-dependent manner above 100 µM and was accumulated in specific metal ion sinks. The copper-sensitive probe Phen Green SK was used to characterize copper transport across the plasma membrane of CSB cells. The transport system (K(m) = 583 µM; V(max) = 177 × 10(-6) %?F min(-1) protoplast(-1)) was regulated by copper availability in the culture medium, stimulated by Ca(2+) and inhibited by Zn(2+). The pH-sensitive fluorescent probe ACMA (9-amino-6-chloro-2-methoxyacridine) was used to evaluate the involvement of proton-dependent copper transport across the tonoplast. Cu(2+) compartmentation in the vacuole was dependent on the transmembrane pH gradient generated by both V-H(+)-ATPase and V-H(+)-pyrophosphatase (PPase). High copper levels in the growth medium did not affect the activity of V-H(+)-PPase but decreased the magnitude of the H(+) gradient generated by V-H(+)-ATPase. Expression studies of VvCTr genes showed that VvCTr1 and VvCTr8 were distinctly affected by CuSO(4) availability in grape cell cultures and that both genes were highly expressed in the green stage of grape berries. PMID:22952251

Martins, Viviana; Hanana, Mohsen; Blumwald, Eduardo; Gerós, Hernâni

2012-09-05

468

Manganese in copper solvent extraction and electrowinning  

Microsoft Academic Search

In the copper solvent extraction–electrowinning (SX–EW) process, Mn2+ entrained in the organic solution may be transferred to the loaded electrolyte. It will then be oxidised during copper EW. The high-oxidation state manganese formed may in turn return to the SX circuit. The presence of high-oxidation state manganese has been associated with deterioration in the phase separation characteristics of the organic

C. Y. Cheng; C. A. Hughes; K. R. Barnard; K. Larcombe

2000-01-01

469

Electro-deposited copper in bismuth telluride  

Microsoft Academic Search

Observations have been made of the electrical conductivity as a function of time in single-crystal Bi2Te3 during copper plating. The diffusion coefficient along the basal planes is so high that the copper is deposited internally. It has been found that there is a saturation effect which depends on the plating current density, as well as a change of conductivity when

T A McCarthy; H J Goldsmid

1970-01-01