WorldWideScience

Sample records for copper carbonates

  1. Electron Percolation In Copper Infiltrated Carbon

    Science.gov (United States)

    Krcho, Stanislav

    2015-11-01

    The work describes the dependence of the electrical conductivity of carbon materials infiltrated with copper in a vacuum-pressure autoclave on copper concentration and on the effective pore radius of the carbon skeleton. In comparison with non-infiltrated material the electrical conductivity of copper infiltrated composite increased almost 500 times. If the composite contained less than 7.2 vol% of Cu, a linear dependence of the electrical conductivity upon cupper content was observed. If infiltrated carbon contained more than 7.2 vol% of Cu, the dependence was nonlinear - the curve could be described by a power formula (x - xc)t. This is a typical formula describing the electron percolation process in regions containing higher Cu fraction than the critical one. The maximum measured electrical conductivity was 396 × 104 Ω-1 m-1 for copper concentration 27.6 vol%. Experiments and analysis of the electrical conductivity showed that electron percolation occurred in carbon materials infiltrated by copper when the copper volume exceeded the critical concentration. The analysis also showed a sharp increase of electrical conductivity in composites with copper concentration higher than the threshold, where the effective radius of carbon skeleton pores decreased to 350 nanometres.

  2. Studies on copper coating on carbon fibers

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The weak interface bonding of metal matrix reinforced by carbon fibers is the central problem of fabricating such composites. Depositing copper coating on carbon fibers is regarded as a feasible method to solve the problem. In this paper, copper coating has been deposited on the fibers through both electroless deposition and electroplating methods. Two kinds of complexing agents and two stabilizing agents are taken during the electroless plating process. The solution is stable, and little extraneous component is absorbed on the surface. After adding additive agents and increasing the concentration of H2SO4 to the acid cupric sulfate electrolyte, the "black core" during usual electroplating process is avoided. The quality of copper coating is analyzed using SEM and XRD, etc.

  3. Structure evolution on annealing of copper-doped carbon film

    Energy Technology Data Exchange (ETDEWEB)

    Onoprienko, A.A. [Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhyzhanovsky St., 03142 Kiev (Ukraine)]. E-mail: onopr@ipms.kiev.ua; Danilenko, N.I. [Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhyzhanovsky St., 03142 Kiev (Ukraine); Kossko, I.A. [Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhyzhanovsky St., 03142 Kiev (Ukraine)

    2007-06-13

    Thin copper-doped (8 at.% Cu) carbon film was deposited by direct current magnetron sputtering of composite graphite/copper target in argon plasma. The evolution of film structure on annealing at 600 deg. C in a vacuum has been studied by transmission electron microscopy and electron diffraction. The as-deposited film was amorphous with copper atoms uniformly distributed over the film volume. Annealing resulted in precipitation of copper particles within carbon film followed by the decrease in the density of copper particles and increase in particle average size with annealing time due to diffusion coalescence within the ensemble of copper particles. The coalescence occurred by the mixed mechanism of bulk and surface diffusion of copper atoms within carbon film that contained a large number of structural defects. As a result, the mean radius of copper particles in ensemble changed as R-bar {sup 5} {approx} t.

  4. Carbon Coating Of Copper By Arc-Discharge Pyrolysis

    Science.gov (United States)

    Ebihara, Ben T.; Jopek, Stanley

    1988-01-01

    Adherent, abrasion-resistant coat deposited with existing equipment. Carbon formed and deposited as coating on copper substrate by pyrolysis of hydrocarbon oil in electrical-arc discharges. Technique for producing carbon deposits on copper accomplished with electrical-discharge-machining equipment used for cutting metals. Applications for new coating technique include the following: solar-energy-collecting devices, coating of metals other than copper with carbon, and carburization of metal surfaces.

  5. Structures of ultrathin copper nanowires encapsulated in carbon nanotubes

    Science.gov (United States)

    Choi, Won Young; Kang, Jeong Won; Hwang, Ho Jung

    2003-11-01

    We have investigated the structures of copper nanowires encapsulated in carbon nanotubes using a structural optimization process applied to the steepest descent method. The results showed that the stable morphology of the cylindrical ultrathin copper nanowires in carbon nanotubes is multishell packs consisting of coaxial cylindrical shells. As the diameter of carbon nanotubes increased, the encapsulated copper nanowires have the face-centered-cubic structure as the bulk. The circular rolling of a triangular network can explain the structures of ultrathin multishell copper nanowires encapsulated in carbon nanotubes.

  6. Preparation and structure of carbon encapsulated copper nanoparticles

    Science.gov (United States)

    Hao, Chuncheng; Xiao, Feng; Cui, Zuolin

    2008-01-01

    Carbon-encapsulated copper nanoparticles were synthesized by a modified arc plasma method using methane as carbon source. The particles were characterized in detail by transmission electron microscope, high-resolution transmission electron microscopy, selected-area electron diffraction, X-ray diffraction, thermogravimetric and differential scanning calorimetry. The encapsulated copper nanoparticles were about 30 nm in diameter with 3-5 nm graphitic carbon shells. The outside graphitic carbon layers effectively prevented unwanted oxidation of the copper inside. The effect of the ratio of He/CH4 on the morphologies and the formation of the carbon shell were investigated.

  7. Preparation and structure of carbon encapsulated copper nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hao Chuncheng, E-mail: clx@qust.edu.cn; Xiao Feng; Cui Zuolin [Qingdao University of Science and Technology, Shandong Key Lab for Nanostructured Materials (China)

    2008-01-15

    Carbon-encapsulated copper nanoparticles were synthesized by a modified arc plasma method using methane as carbon source. The particles were characterized in detail by transmission electron microscope, high-resolution transmission electron microscopy, selected-area electron diffraction, X-ray diffraction, thermogravimetric and differential scanning calorimetry. The encapsulated copper nanoparticles were about 30 nm in diameter with 3-5 nm graphitic carbon shells. The outside graphitic carbon layers effectively prevented unwanted oxidation of the copper inside. The effect of the ratio of He/CH{sub 4} on the morphologies and the formation of the carbon shell were investigated.

  8. Copper modified carbon molecular sieves for selective oxygen removal

    Science.gov (United States)

    Sharma, Pramod K. (Inventor); Seshan, Panchalam K. (Inventor)

    1992-01-01

    Carbon molecular sieves modified by the incorporation of finely divided elemental copper useful for the selective sorption of oxygen at elevated temperatures. The carbon molecular sieves can be regenerated by reduction with hydrogen. The copper modified carbon molecular sieves are prepared by pyrolysis of a mixture of a copper-containing material and polyfunctional alcohol to form a sorbent precursor. The sorbent precursors are then heated and reduced to produce copper modified carbon molecular sieves. The copper modified carbon molecular sieves are useful for sorption of all concentrations of oxygen at temperatures up to about 200.degree. C. They are also useful for removal of trace amount of oxygen from gases at temperatures up to about 600.degree. C.

  9. Copper crystallite in carbon molecular sieves for selective oxygen removal

    Science.gov (United States)

    Sharma, Pramod K. (Inventor); Seshan, Panchalam K. (Inventor)

    1993-01-01

    Carbon molecular sieves modified by the incorporation of finely divided elemental copper useful for the selective sorption of oxygen at elevated temperatures. The carbon molecular sieves can be regenerated by reduction with hydrogen. The copper modified carbon molecular sieves are prepared by pyrolysis of a mixture of a copper-containing material and polyfurfuryl alcohol to form a sorbent precursor. The sorbent precursors are then heated and reduced to produce copper modified carbon molecular sieves. The copper modified carbon molecular sieves are useful for sorption of all concentrations of oxygen at temperatures up to about 200.degree. C. They are also useful for removal of trace amount of oxygen from gases at temperatures up to about 600.degree. C.

  10. Synergistic strengthening effect of nanocrystalline copper reinforced with carbon nanotubes.

    Science.gov (United States)

    Wang, Hu; Zhang, Zhao-Hui; Hu, Zheng-Yang; Wang, Fu-Chi; Li, Sheng-Lin; Korznikov, Elena; Zhao, Xiu-Chen; Liu, Ying; Liu, Zhen-Feng; Kang, Zhe

    2016-05-17

    In this study, a novel multi-walled carbon nanotubes reinforced nanocrystalline copper matrix composite with super high strength and moderate plasticity was synthesized. We successfully overcome the agglomeration problem of the carbon nanotubes and the grain growth problem of the nanocrystalline copper matrix by combined use of the electroless deposition and spark plasma sintering methods. The yield strength of the composite reach up to 692 MPa, which is increased by 2 and 5 times comparing with those of the nanocrystalline and coarse copper, respectively. Simultaneously, the plasticity of the composite was also significantly increased in contrast with that of the nanocrystalline copper. The increase of the density of the carbon nanotubes after coating, the isolation effect caused by the copper coating, and the improvement of the compatibility between the reinforcements and matrix as well as the effective control of the grain growth of the copper matrix all contribute to improving the mechanical properties of the composite. In addition, a new strengthening mechanism, i.e., the series-connection effect of the nanocrystalline copper grains introduced by carbon nanotubes, is proposed to further explain the mechanical behavior of the nanocomposite.

  11. Preparation of Nickel-Copper Bilayers Coated on Single-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Zhong Zheng

    2015-01-01

    Full Text Available Due to oxidizability of copper coating on carbon nanotubes, the interfacial bond strength between copper coating and its matrix is weak, which leads to the reduction of the macroscopic properties of copper matrix composite. The electroless coating technics was applied to prepare nickel-copper bilayers coated on single-walled carbon nanotubes. The coated single-walled carbon nanotubes were characterized through transmission electron microscope spectroscopy, field-emission electron microscope spectroscopy, X-ray diffractometry, and thermogravimetric analysis. The results demonstrated that the nickel-copper bilayers coated on single-walled carbon nanotubes possessed higher purity of unoxidized copper fine-grains than copper monolayers.

  12. Copper nanoparticles encapsulated in multi-shell carbon cages

    Energy Technology Data Exchange (ETDEWEB)

    Schaper, A.K. [Material Sciences Center and Department of Geosciences, Philipps University, Hans-Meerwein-Str., 35032, Marburg (Germany); Hou, H. [Material Sciences Center and Department of Chemistry, Philipps University, Hans-Meerwein-Str., 35032, Marburg (Germany); University of Akron, Ohio (United States); Greiner, A. [Material Sciences Center and Department of Chemistry, Philipps University, Hans-Meerwein-Str., 35032, Marburg (Germany); Schneider, R. [Institute of Physics, Humboldt University, Invalidenstr. 110, 10115, Berlin (Germany); Phillipp, F. [Max Planck Institute for Metal Research, Heisenbergstr. 3, 70569, Stuttgart (Germany)

    2004-01-01

    Nanoparticles are attracting increasing interest because of their high potential for a great number of practical applications, such as optical and electronic devices, nanoscale storage, and delivery systems. Using Cu-phthalocyanine as precursor material, we have synthesized multi-shell graphitic carbon nanospheres without and with metal encapsulation, depending on the pyrolysis conditions. The encapsulated elemental copper nanocrystals achieved using that route were of the order of 50 nm in size. The particles were characterized in detail by high-resolution transmission electron microscopy (HRTEM) and by energy filtering microscopy (EFTEM). The concentric graphitic carbon shells of the as-grown particles were clearly discernable. After in situ high-temperature annealing, an increase in the degree of order was observed. Under high-voltage electron irradiation and heating, a melting point reduction of the enclosed nanosized copper of more than 200 K could be detected, as compared to the melting point 1083 C of bulk copper. Time-resolved imaging revealed the displacement of the melting copper by migration through the carbon shells, leaving intact carbon cages with a central hole. At intermediate stages of this process the transformation into a hexagonal morphology of the copper nanocrystals was observed. (orig.)

  13. Hollow silica-copper-carbon anodes using copper metal-organic frameworks as skeletons

    Science.gov (United States)

    Sun, Zixu; Xin, Fengxia; Cao, Can; Zhao, Chongchong; Shen, Cai; Han, Wei-Qiang

    2015-12-01

    Hollow silica-copper-carbon (H-SCC) nanocomposites are first synthesized using copper metal-organic frameworks as skeletons to form Cu-MOF@SiO2 and then subjected to heat treatment. In the composites, the hollow structure and the void space from the collapse of the MOF skeleton can accommodate the huge volume change, buffer the mechanical stress caused by lithium ion insertion/extraction and maintain the structural integrity of the electrode and a long cycling stability. The ultrafine copper with a uniform size of around 5 nm and carbon with homogeneous distribution from the decomposition of the MOF skeleton can not only enhance the electrical conductivity of the composite and preserve the structural and interfacial stabilization, but also suppress the aggregation of silica nanoparticles and cushion the volume change. In consequence, the resulting material as an anode for lithium-ion batteries (LIBs) delivers a reversible capacity of 495 mA h g-1 after 400 cycles at a current density of 500 mA g-1. The synthetic method presented in this paper provides a facile and low-cost strategy for the large-scale production of hollow silica/copper/carbon nanocomposites as an anode in LIBs.Hollow silica-copper-carbon (H-SCC) nanocomposites are first synthesized using copper metal-organic frameworks as skeletons to form Cu-MOF@SiO2 and then subjected to heat treatment. In the composites, the hollow structure and the void space from the collapse of the MOF skeleton can accommodate the huge volume change, buffer the mechanical stress caused by lithium ion insertion/extraction and maintain the structural integrity of the electrode and a long cycling stability. The ultrafine copper with a uniform size of around 5 nm and carbon with homogeneous distribution from the decomposition of the MOF skeleton can not only enhance the electrical conductivity of the composite and preserve the structural and interfacial stabilization, but also suppress the aggregation of silica nanoparticles and

  14. Method for aqueous gold thiosulfate extraction using copper-cyanide pretreated carbon adsorption

    Science.gov (United States)

    Young, Courtney; Melashvili, Mariam; Gow, Nicholas V

    2013-08-06

    A gold thiosulfate leaching process uses carbon to remove gold from the leach liquor. The activated carbon is pretreated with copper cyanide. A copper (on the carbon) to gold (in solution) ratio of at least 1.5 optimizes gold recovery from solution. To recover the gold from the carbon, conventional elution technology works but is dependent on the copper to gold ratio on the carbon.

  15. XPS investigation of copper corrosion in hydro-carbonate electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Sieber, I.; Hildebrand, H.; Schmuki, P. [University Erlangen-Nuremberg, Martensstr.7, D-91058 Erlangen (Germany); Kaluzhina, S.A. [Voronezh State University, University Sq.1, 394006 Voronezh (Russian Federation)

    2004-07-01

    Problems of corrosion and effective methods of metal protection are still actual in the present days. Special interest is in copper material, which as basic component of heat exchanger constructions can corrode in contact with carbonate water. The intensity of the corrosion destruction depends on the carbon water concentration and thermal conditions in the system. The present paper provides new insights into the role of the HCO{sub 3}{sup -} - ions in the corrosion process of copper. Copper samples after anodic oxidation in 0.02 and 0.1 M NaHCO{sub 3} have been studied using XPS and SEM. The presence of carbonate compounds in the passive film in 0.1 M NaHCO{sub 3} was established by XPS analysis all over the surface. These compounds are responsible for the protective character of the passive film towards local destruction. In the 0.02 M NaHCO{sub 3} electrolyte carbonate compounds were not found at places of pit formation after multi-cycling of the sample. (authors)

  16. Copper Decoration of Carbon Nanotubes and High Resolution Electron Microscopy

    Science.gov (United States)

    Probst, Camille

    A new process of decorating carbon nanotubes with copper was developed for the fabrication of nanocomposite aluminum-nanotubes. The process consists of three stages: oxidation, activation and electroless copper plating on the nanotubes. The oxidation step was required to create chemical function on the nanotubes, essential for the activation step. Then, catalytic nanoparticles of tin-palladium were deposited on the tubes. Finally, during the electroless copper plating, copper particles with a size between 20 and 60 nm were uniformly deposited on the nanotubes surface. The reproducibility of the process was shown by using another type of carbon nanotube. The fabrication of nanocomposites aluminum-nanotubes was tested by aluminum vacuum infiltration. Although the infiltration of carbon nanotubes did not produce the expected results, an interesting electron microscopy sample was discovered during the process development: the activated carbon nanotubes. Secondly, scanning transmitted electron microscopy (STEM) imaging in SEM was analysed. The images were obtained with a new detector on the field emission scanning electron microscope (Hitachi S-4700). Various parameters were analysed with the use of two different samples: the activated carbon nanotubes (previously obtained) and gold-palladium nanodeposits. Influences of working distance, accelerating voltage or sample used on the spatial resolution of images obtained with SMART (Scanning Microscope Assessment and Resolution Testing) were analysed. An optimum working distance for the best spatial resolution related to the sample analysed was found for the imaging in STEM mode. Finally, relation between probe size and spatial resolution of backscattered electrons (BSE) images was studied. An image synthesis method was developed to generate the BSE images from backscattered electrons coefficients obtained with CASINO software. Spatial resolution of images was determined using SMART. The analysis shown that using a probe

  17. Antibacterial Carbon Nanotubes by Impregnation with Copper Nanostructures

    Science.gov (United States)

    Palza, Humberto; Saldias, Natalia; Arriagada, Paulo; Palma, Patricia; Sanchez, Jorge

    2017-08-01

    The addition of metal-based nanoparticles on carbon nanotubes (CNT) is a relevant method producing multifunctional materials. In this context, CNT were dispersed in an ethanol/water solution containing copper acetate for their impregnation with different copper nanostructures by either a non-thermal or a thermal post-synthesis treatment. Our simple method is based on pure CNT in an air atmosphere without any other reagents. Particles without thermal treatment were present as a well-dispersed layered copper hydroxide acetate nanostructures on CNT, as confirmed by scanning and transmission (TEM) electron microscopies, and showing a characteristic x-ray diffraction peak at 6.6°. On the other hand, by thermal post-synthesis treatment at 300°C, these layered nanostructures became Cu2O nanoparticles of around 20 nm supported on CNT, as confirmed by TEM images and x-ray diffraction peaks. These copper nanostructures present on the CNT surface rendered antibacterial behavior to the resulting hybrid materials against both Staphylococcus aureus and Escherichia coli. These findings present for the first time a simple method for producing antibacterial CNT by direct impregnation of copper nanostructures.

  18. Building reactive copper centers in human carbonic anhydrase II.

    Science.gov (United States)

    Song, He; Weitz, Andrew C; Hendrich, Michael P; Lewis, Edwin A; Emerson, Joseph P

    2013-08-01

    Reengineering metalloproteins to generate new biologically relevant metal centers is an effective a way to test our understanding of the structural and mechanistic features that steer chemical transformations in biological systems. Here, we report thermodynamic data characterizing the formation of two type-2 copper sites in carbonic anhydrase and experimental evidence showing one of these new, copper centers has characteristics similar to a variety of well-characterized copper centers in synthetic models and enzymatic systems. Human carbonic anhydrase II is known to bind two Cu(2+) ions; these binding events were explored using modern isothermal titration calorimetry techniques that have become a proven method to accurately measure metal-binding thermodynamic parameters. The two Cu(2+)-binding events have different affinities (K a approximately 5 × 10(12) and 1 × 10(10)), and both are enthalpically driven processes. Reconstituting these Cu(2+) sites under a range of conditions has allowed us to assign the Cu(2+)-binding event to the three-histidine, native, metal-binding site. Our initial efforts to characterize these Cu(2+) sites have yielded data that show distinctive (and noncoupled) EPR signals associated with each copper-binding site and that this reconstituted enzyme can activate hydrogen peroxide to catalyze the oxidation of 2-aminophenol.

  19. Sintering studies on iron-carbon-copper compacts

    Directory of Open Access Journals (Sweden)

    Perianayagam Philomen-D-Anand Raj

    2016-01-01

    Full Text Available Sintered Iron-Carbon-Copper parts are among the most widely used powder metallurgy product in automobile. In this paper, studies have been carried out to find out the sintering characteristics of iron-carbon-copper compacts when sintered in nitrogen atmosphere. The effects of various processing parameters on the sintering characteristics were studied. The various processing parameters considered were compaction pressure, green density and sintering temperature. The sintering characteristics determined were sintered density, porosity, dimensional change, micro hardness and radial crush strength. The results obtained have been discussed on the basis of micro structural observations. The characteristics of SEM fractography were also used to determine the mechanism of fracture. The fracture energy is strongly dependent on density of the compact.

  20. Effect of Reaction Temperature on Carbon Yield and Morphology of CNTs on Copper Loaded Nickel Nanoparticles

    National Research Council Canada - National Science Library

    Ming, Hu; Peiling, Ding; Yunlong, Zhang; Jing, Gao; Xiaoxue, Ren

    2016-01-01

      This investigation was attempted to introduce carbon nanotubes (CNTs) onto surface of copper powders in order to improve heat transfer performance of copper matrix for engineering application of electrical packaging materials...

  1. The fabrication of carbon nanotubes reinforced copper coating by a kinetic spray process.

    Science.gov (United States)

    Xiong, Yuming; Kang, Kicheol; Yoon, Sanghoon; Lee, Changhee

    2008-10-01

    In this paper, multiwalled carbon nanotubes (MWCNTs) reinforced copper coating was deposited on copper sheet through kinetic spraying process. Effect of heat treatment on microstructure, conductivity, and hardness of the coating was investigated. The incompact MWCNTs reinforced copper coating exhibits a comparable hardness, but higher electrical resistivity than pure copper coating. After heat treatment at 600 degrees C for 2 h, the hardness of copper coatings significantly decreased due to the substantial grain growth. MWCNTs reinforced copper coating showed stable hardness and electrical conductivity against heat treatment owing to the inhibition of CNTs to grain growth and the intimate contact between CNTs and copper matrix.

  2. A method for synthesizing large quantities of carbon nanotubes and encapsulated copper nanowires

    Science.gov (United States)

    Setlur, A. A.; Lauerhaas, J. M.; Dai, J. Y.; Chang, R. P. H.

    1996-07-01

    A method using a hydrogen arc for synthesizing large quantities of carbon nanotubes filled with pure copper is reported. The interaction of small copper clusters with polycyclic aromatic hydrocarbons (PAHs) is shown to form carbon nanotubes and encapsulated copper nanowires. The effectiveness of this model is demonstrated by showing that no copper filled nanotubes are formed in a helium arc that does not generate PAHs. A direct proof of this model is demonstrated by using pyrene, a PAH molecule, to grow carbon nanotubes and encapsulated copper nanowires.

  3. Determination of Copper, Total Chromium and Silver in Impregnated Carbon

    Directory of Open Access Journals (Sweden)

    Beer Singh

    1998-10-01

    Full Text Available Carbon samples were impregnated with ammonical solutions of silver salt alone and in combination with Cu and Cr salts. The impregnated samples were characterised for Cu, total Cr and Ag. Copper was extracted as CuCl/sub 2/ using concentrated HCl and Cr with NaOH. Silver was extracted from impregnated carbon using HNO3 and sodium thiosulphate (Na/sub 2/S/sub 2/O/sub 3/-5H/sub 2/0 and ashed impregnated carbons using aqua regia. The extracted metals in their solutions were quantitatively determined by titrimetric method and atomic absorption spectroscopy. The results were within acceptable limits of error. Sodium thiosulphate is recommended for extraction of Ag, as it accomplishes complete leaching of Ag faster than the other extracting agents.

  4. Electrostatic-assembly carbon nanotube-implanted copper composite spheres

    Energy Technology Data Exchange (ETDEWEB)

    Xu Longshan; Chen Xiaohua; Pan Weiying; Li Wenhua; Yang Zhi; Pu Yuxing [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China)

    2007-10-31

    A unique method for synthesis of multi-walled-carbon-nanotube- (MWCNT-) implanted copper composite spheres is reported. It involves Cu ions combining with functionalized MWCNTs at molecular level and formation of spheres after reduction, nucleation and growth of Cu ions attaching to the surface of MWCNTs. The MWCNT-implanted composite spheres allow MWCNTs to avoid being damaged and effectively bond to the matrix. This unique spherical structure will serve as an excellent candidate as powders for the fabrication of a bulk MWCNT-reinforced composite with high strength and good thermal and electrical conductivity.

  5. Catalytic effect of activated carbon on bioleaching of low-grade primary copper sulfide ores

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The catalytic effect of activated carbon on the bioleaching of low-grade primary copper sulfide ores using mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was investigated. The results show that the addition of activated carbon can greatly accelerate the rate and efficiency of copper dissolution from low-grade primary copper sulfide ores. The solution with the concentration of 3.0 g/L activated carbon is most beneficial to the dissolution of copper. The resting time of the mixture of activated carbon and ores has an impact on the bioleaching of low-grade primary copper sulfide ores. The 2 d resting time is most favorable to the dissolution of copper. The enhanced dissolution rate and efficiency of copper can be attributed to the galvanic interaction between activated carbon and chalcopyrite. The addition of activated carbon obviously depresses the dissolution of iron and the bacterial oxidation of ferrous ions in solution. The lower redox potentials are more favorable to the copper dissolution than the higher potentials for low-grade primary copper sulfide ores in the presence of activated carbon.

  6. Effects of Two Purification Pretreatments on Electroless Copper Coating over Single-Walled Carbon Nanotubes

    OpenAIRE

    Zhong Zheng; Lianjie Li; Shijie Dong; Anchun Xiao; Shixuan Sun; Sinian Li

    2014-01-01

    To achieve the reinforcement of copper matrix composite by single-walled carbon nanotubes, a three-step-refluxing purification of carbon nanotubes sample with HNO3-NaOH-HCl was proposed and demonstrated. A previously reported purification process using an electromagnetic stirring with H2O2/HCl mixture was also repeated. Then, the purified carbon nanotubes were coated with copper by the same electroless plating process. At the end, the effects of the method on carbon nanotubes themselves and o...

  7. Copper-decorated carbon nanotubes-based composite electrodes for nonenzymatic detection of glucose

    NARCIS (Netherlands)

    Pop, A.; Manea, F.; Orha, C.; Motoc, S.; Llinoiu, E.; Vaszilcsin, N.; Schoonman, J.

    2012-01-01

    The aim of this study was to prepare three types of multiwall carbon nanotubes (CNT)-based composite electrodes and to modify their surface by copper electrodeposition for nonenzymatic oxidation and determination of glucose from aqueous solution. Copper-decorated multiwall carbon nanotubes composite

  8. Copper on activated carbon for catalytic wet air oxidation

    Directory of Open Access Journals (Sweden)

    Nora Dolores Martínez

    2009-03-01

    Full Text Available Textile industry is an important source of water contamination. Some of the organic contaminants cannot be eliminated by nature in a reasonable period. Heterogeneous catalytic wet air oxidation is one of the most effective methods to purify wastewater with organic contaminants. In this work, catalysts based on copper supported on activated carbon were synthesized. The activated carbons were obtained from industrial wastes (apricot core and grape stalk of San Juan, Argentina. These were impregnated with a copper salt and thermically treated in an inert atmosphere. Analysis of specific surface, pore volume, p zc, acidity, basicity and XRD patterns were made in order to characterize the catalysts. The catalytic activity was tested in the oxidation of methylene blue (MB and polyvinyl alcohol (PVA in aqueous phase with pure oxygen. Reaction tests were carried out in a Parr batch reactor at different temperatures, with a 0.2 MPa partial pressure of oxygen. The amount of unconverted organics was measured by spectrophotometry. Higher temperatures were necessary for the degradation of PVA compared to those for methylene blue.

  9. Copper-encapsulated vertically aligned carbon nanotube arrays.

    Science.gov (United States)

    Stano, Kelly L; Chapla, Rachel; Carroll, Murphy; Nowak, Joshua; McCord, Marian; Bradford, Philip D

    2013-11-13

    A new procedure is described for the fabrication of vertically aligned carbon nanotubes (VACNTs) that are decorated, and even completely encapsulated, by a dense network of copper nanoparticles. The process involves the conformal deposition of pyrolytic carbon (Py-C) to stabilize the aligned carbon-nanotube structure during processing. The stabilized arrays are mildly functionalized using oxygen plasma treatment to improve wettability, and they are then infiltrated with an aqueous, supersaturated Cu salt solution. Once dried, the salt forms a stabilizing crystal network throughout the array. After calcination and H2 reduction, Cu nanoparticles are left decorating the CNT surfaces. Studies were carried out to determine the optimal processing parameters to maximize Cu content in the composite. These included the duration of Py-C deposition and system process pressure as well as the implementation of subsequent and multiple Cu salt solution infiltrations. The optimized procedure yielded a nanoscale hybrid material where the anisotropic alignment from the VACNT array was preserved, and the mass of the stabilized arrays was increased by over 24-fold because of the addition of Cu. The procedure has been adapted for other Cu salts and can also be used for other metal salts altogether, including Ni, Co, Fe, and Ag. The resulting composite is ideally suited for application in thermal management devices because of its low density, mechanical integrity, and potentially high thermal conductivity. Additionally, further processing of the material via pressing and sintering can yield consolidated, dense bulk composites.

  10. The fungicidal properties of the carbon materials obtained from chitin and chitosan promoted by copper salts

    Energy Technology Data Exchange (ETDEWEB)

    Ilnicka, Anna, E-mail: annakucinska@o2.pl; Walczyk, Mariusz; Lukaszewicz, Jerzy P.

    2015-07-01

    Renewable raw materials chitin and chitosan (N-deacetylated derivative of chitin) were subjected to action of different copper modifiers that were carbonized in the atmosphere of the N{sub 2} inert gas. As a result of the novel manufacturing procedure, a series of carbon materials was obtained with developed surface area and containing copper derivatives of differentiated form, size, and dispersion. The copper modifier and manufacturing procedure (concentration, carbonization temperature) influence the physical–chemical and fungicide properties of the carbons. The received carbons were chemically characterized using several methods like low-temperature adsorption of nitrogen, X-ray diffraction analysis, scanning electron microscopy, cyclic voltammetry, elemental analysis, and bioassay. Besides chemical testing, some biological tests were performed and let to select carbons with the highest fungicidal activity. Such carbons were characteristic of the specific form of copper derivatives occurring in them, i.e., nanocrystallites of Cu{sup 0} and/or Cu{sub 2}O of high dispersion on the surface of carbon. The carbons may find an application as effective contact fungistatic agents in cosmetology, medicine, food industry, etc. - Highlights: • The novel manufacturing procedure yields new functional carbon materials. • Two biopolymers chitin and chitosan can undergo copper(II) ion modification. • The Cu-modified carbon materials exhibit high fungicidal activity. • The fungicidal activity results from the presence of Cu{sup 0} and Cu{sub 2}O nano-crystallites.

  11. Microstructure and properties of pure iron/copper composite cladding layers on carbon steel

    Science.gov (United States)

    Wan, Long; Huang, Yong-xian; Lü, Shi-xiong; Huang, Ti-fang; Lü, Zong-liang

    2016-08-01

    In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses of the composite cladding layers. Iron liquid-solid-phase zones were formed at copper/steel and iron interfaces because of the melting of the steel substrate and iron. Iron concentrated in the copper cladding layer was observed to exhibit belt, globule, and dendrite morphologies. The appearance of iron-rich globules indicated the occurrence of liquid phase separation (LPS) prior to solidification, and iron-rich dendrites crystallized without the occurrence of LPS. The maximum microhardness of the iron/steel interface was lower than that of the copper/steel interface because of the diffusion of elemental carbon. All samples fractured in the cladding layers. Because of a relatively lower strength of the copper layer, a short plateau region appeared when shear movement was from copper to iron.

  12. Compound Hertzian Chain Model for Copper-Carbon Nanocomposites' Absorption Spectrum

    CERN Document Server

    Kokabi, Alireza; Saeedi, Saman; Moftakharzadeh, Ali; Vesaghi, Mohammad Ali; Fardmanesh, Mehdi

    2011-01-01

    The infrared range optical absorption mechanism of Carbon-Copper composite thin layer coated on the Diamond-Like Carbon (DLC) buffer layer has been investigated. By consideration of weak interactions between copper nanoparticles in their network, optical absorption is modeled using their coherent dipole behavior induced by the electromagnetic radiation. The copper nanoparticles in the bulk of carbon are assumed as a chain of plasmonic dipoles, which have coupling resonance. Considering nearest neighbor interactions for this metallic nanoparticles, surface plasmon resonance frequency ({\\omega}\

  13. Cobalt promoted copper manganese oxide catalysts for ambient temperature carbon monoxide oxidation.

    Science.gov (United States)

    Jones, Christopher; Taylor, Stuart H; Burrows, Andrew; Crudace, Mandy J; Kiely, Christopher J; Hutchings, Graham J

    2008-04-14

    Low levels of cobalt doping (1 wt%) of copper manganese oxide enhances its activity for carbon monoxide oxidation under ambient conditions and the doped catalyst can display higher activity than current commercial catalysts.

  14. Organic carbon, and not copper, controls denitrification in oxygen minimum zones of the ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Ward, B.B.; Tuit, C.B.; Jayakumar, A.; Rich, J.J.; Moffett, J.; Naqvi, S.W.A.

    Incubation experiments under trace metal clean conditions and ambient oxygen concentrations were used to investigate the response of microbial assemblages in oxygen minimum zones (OMZs) to additions of organic carbon and copper, two factors...

  15. Study on tunable resonator using a cantilevered carbon nanotube encapsulating a copper nanocluster

    Science.gov (United States)

    Kang, Jeong Won; Kim, Ki-Sub; Park, Jungchul; Hwang, Ho Jung

    2011-02-01

    We investigated an ultrahigh frequency carbon nanotube resonator encapsulating a nanocluster, as another tunable resonator, via classical molecular dynamics simulations and continuum models. The fundamental frequency of cantilevered carbon nanotube resonator encapsulating a copper nanocluster could be adjusted by controlling the position of the encapsulated copper nanocluster. Data obtained from the molecular dynamics simulations were analyzed with continuum theory, and we found that statistically the change in the effective mass factor was greatly correlated with the position change of the encapsulated nanocluster.

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

    Science.gov (United States)

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

    2007-12-12

    Carbon nanotubes incorporating copper are highly sought after for nanoelectronic applications. Indeed, several recent studies have demonstrated the production of copper-tipped nanotubes using the chemical vapor deposition method. Here we present the growth and detailed characterization of such copper-tipped nanotubes. The nanotubes grown were of a 'bamboo-like' structure, consisting of stacked cups of graphene, and were produced by chemical vapor deposition employing iron and copper nanoparticles as a catalyst and metal source respectively. Transmission electron microscopy and electron holography analysis of the tips of these nanotubes revealed a small crystalline iron particle on the inner side of the copper tip, with the nanotube structure encapsulating the iron. This form of growth may allow the formation of similar structures with various other metal-tipped carbon nanotubes to be manufactured.

  17. Synthesis of carbon-supported copper catalyst and its catalytic performance in methanol dehydrogenation

    Science.gov (United States)

    Shelepova, Ekaterina V.; Vedyagin, Aleksey A.; Ilina, Ludmila Yu.; Nizovskii, Alexander I.; Tsyrulnikov, Pavel G.

    2017-07-01

    Carbon-supported copper catalyst was prepared by incipient wetness impregnation of Sibunit with an aqueous solution of copper nitrate. Copper loading was 5 wt.%. Temperature of reductive pretreatment was varied within a range of 200-400 °C. The samples were characterized by transmission electron microscopy, X-ray diffraction analysis, X-ray photoelectron and X-ray absorption spectroscopies. Catalytic activity of the samples was studied in a reaction of methanol dehydrogenation. Silica-based catalyst with similar copper loading was used as a reference. It was found that copper is distributed over the surface of support in the form of metallic and partially oxidized particles of about 12-17 nm in size. Diminished interaction of copper with support was supposed to be responsible for high catalytic activity.

  18. Copper-Multiwall Carbon Nanotubes and Copper-Diamond Composites for Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Ellis, Dave L.; Smelyanskiy, Vadim; Foygel, Michael; Rape, Aaron; Singh, Jogender; Vohra, Yogesh K.; Thomas, Vinoy; Otte, Kyle G.; Li, Deyu

    2013-01-01

    This paper reports on the research effort to improve the thermal conductivity of the copper-based alloy NARloy-Z (Cu-3 wt.%Ag-0.5 wt.% Zr), the state-of-the-art alloy used to make combustion chamber liners in regeneratively-cooled liquid rocket engines, using nanotechnology. The approach was to embed high thermal conductivity multiwall carbon nanotubes (MWCNTs) and diamond (D) particles in the NARloy-Z matrix using powder metallurgy techniques. The thermal conductivity of MWCNTs and D have been reported to be 5 to 10 times that of NARloy-Z. Hence, 10 to 20 vol. % MWCNT finely dispersed in NARloy-Z matrix could nearly double the thermal conductivity, provided there is a good thermal bond between MWCNTs and copper matrix. Quantum mechanics-based modeling showed that zirconium (Zr) in NARloy-Z should form ZrC at the MWCNT-Cu interface and provide a good thermal bond. In this study, NARloy-Z powder was blended with MWCNTs in a ball mill, and the resulting mixture was consolidated under high pressure and temperature using Field Assisted Sintering Technology (FAST). Microstructural analysis showed that the MWCNTs, which were provided as tangles of MWCNTs by the manufacturer, did not detangle well during blending and formed clumps at the prior particle boundaries. The composites made form these powders showed lower thermal conductivity than the base NARloy-Z. To eliminate the observed physical agglomeration, tangled multiwall MWCNTs were separated by acid treatment and electroless plated with a thin layer of chromium to keep them separated during further processing. Separately, the thermal conductivities of MWCNTs used in this work were measured, and the results showed very low values, a major factor in the low thermal conductivity of the composite. On the other hand, D particles embedded in NARloy-Z matrix showed much improved thermal conductivity. Elemental analysis showed migration of Zr to the NARloy-Z-D interface to form ZrC, which appeared to provide a low contact

  19. Copper Multiwall Carbon Nanotubes and Copper-Diamond Composites for Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Ellis, Dave L.; Smelyanskiy, Vadim; Foygel, Michael; Singh, Jogender; Rape, Aaron; Vohra, Yogesh; Thomas, Vinoy; Li, Deyu; Otte, Kyle

    2013-01-01

    This paper reports on the research effort to improve the thermal conductivity of the copper-based alloy NARloy-Z (Cu-3 wt.%Ag-0.5 wt.% Zr), the state-of-the-art alloy used to make combustion chamber liners in regeneratively-cooled liquid rocket engines, using nanotechnology. The approach was to embed high thermal conductivity multiwall carbon nanotubes (MWCNTs) and diamond (D) particles in the NARloy-Z matrix using powder metallurgy techniques. The thermal conductivity of MWCNTs and D have been reported to be 5 to 10 times that of NARloy-Z. Hence, 10 to 20 vol. % MWCNT finely dispersed in NARloy-Z matrix could nearly double the thermal conductivity, provided there is a good thermal bond between MWCNTs and copper matrix. Quantum mechanics-based modeling showed that zirconium (Zr) in NARloy-Z should form ZrC at the MWCNT-Cu interface and provide a good thermal bond. In this study, NARloy-Z powder was blended with MWCNTs in a ball mill, and the resulting mixture was consolidated under high pressure and temperature using Field Assisted Sintering Technology (FAST). Microstructural analysis showed that the MWCNTs, which were provided as tangles of MWCNTs by the manufacturer, did not detangle well during blending and formed clumps at the prior particle boundaries. The composites made form these powders showed lower thermal conductivity than the base NARloy-Z. To eliminate the observed physical agglomeration, tangled multiwall MWCNTs were separated by acid treatment and electroless plated with a thin layer of chromium to keep them separated during further processing. Separately, the thermal conductivities of MWCNTs used in this work were measured, and the results showed very low values, a major factor in the low thermal conductivity of the composite. On the other hand, D particles embedded in NARloy-Z matrix showed much improved thermal conductivity. Elemental analysis showed migration of Zr to the NARloy-Z-D interface to form ZrC, which appeared to provide a low contact

  20. Effect of copper carbonate and zinc oxide applied to seeds on copper and zinc uptake by maize seedlings

    Directory of Open Access Journals (Sweden)

    Marcos Altomani Neves Dias

    2016-01-01

    Full Text Available ABSTRACT Seed treatment is an interesting alternative to deliver micronutrients to field crops. The aim of this study was to investigate the uptake of Cu and Zn by maize seedlings, with the application of the water-insoluble sources copper carbonate and zinc oxide as seed treatment. Treatments were composed of a control (untreated seeds, five doses of copper (0.14, 0.28, 0.56, 1.12 and 2.24 mg Cu∙seed–1 and zinc (0.55, 1.10, 2.20, 4.40 and 8.80 mg Zn∙seed–1 as well as five doses of copper and zinc combined (0.14, 0.28, 0.56, 1.12 and 2.24 mg Cu∙seed–1; 0.55, 1.10, 2.20, 4.40 and 8.80 mg Zn∙seed–1. Plants were cultivated in sand, under greenhouse conditions and, at the two-leaf stage (15 days, the root and shoot tissues dry mass and concentration of Cu and Zn were determined, which allowed to calculate accumulation and uptake efficiency of these micronutrients by maize plants. Seed treatment with copper carbonate and zinc oxide increased both root and shoot concentration and accumulation of Cu and Zn in maize seedlings, with two fully expanded leaves. Cu tended to accumulate in roots, while Zn was more evenly distributed among roots and shoots. Combined application of copper carbonate and zinc oxide resulted in lower uptake of both Cu and Zn by maize if compared to individual applications, with Cu uptake reduced in a higher extent.

  1. Copper-cerium oxides supported on carbon nanomaterial for preferential oxidation of carbon monoxide

    Institute of Scientific and Technical Information of China (English)

    高美怡; 江楠; 赵宇宏; 徐长进; 苏海全; 曾尚红

    2016-01-01

    The CuxO-CeO2/Fe@CNSs, CuxO-CeO2/MWCNTs-Co and CuxO-CeO2/MWCNTs-Ni catalysts were prepared by the im-pregnation method and characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffrac-tion, H2-temperature programmed reduction and N2 adsorption-desorption techniques. It was found that the Fe nanoparticles were encapsulated into the multi-layered carbon nanospheres (CNSs). However, the multi-wall carbon nanotubes (MWCNTS) were generated on the Co/Al2O3 and Ni/Al2O3 precursor. The addition of carbon nanomaterial as supports could improve structural properties and low-temperature activity of the CuO-CeO2 catalyst, and save the used amount of metal catalysts in the temperature range with high selectivity for CO oxidation. The copper-cerium oxides supported on carbon nanomaterial had good resistence to H2O and CO2.

  2. Impact of carbon on the surface and activity of silica-carbon supported copper catalysts for reduction of nitrogen oxides

    Science.gov (United States)

    Spassova, I.; Stoeva, N.; Nickolov, R.; Atanasova, G.; Khristova, M.

    2016-04-01

    Composite catalysts, prepared by one or more active components supported on a support are of interest because of the possible interaction between the catalytic components and the support materials. The supports of combined hydrophilic-hydrophobic type may influence how these materials maintain an active phase and as a result a possible cooperation between active components and the support material could occur and affects the catalytic behavior. Silica-carbon nanocomposites were prepared by sol-gel, using different in specific surface areas and porous texture carbon materials. Catalysts were obtained after copper deposition on these composites. The nanocomposites and the catalysts were characterized by nitrogen adsorption, TG, XRD, TEM- HRTEM, H2-TPR, and XPS. The nature of the carbon predetermines the composite's texture. The IEPs of carbon materials and silica is a force of composites formation and determines the respective distribution of the silica and carbon components on the surface of the composites. Copper deposition over the investigated silica-carbon composites leads to formation of active phases in which copper is in different oxidation states. The reduction of NO with CO proceeds by different paths on different catalysts due to the textural differences of the composites, maintaining different surface composition and oxidation states of copper.

  3. Copper ions removal from water using functionalized carbon nanotubes–mullite composite as adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Tofighy, Maryam Ahmadzadeh; Mohammadi, Toraj, E-mail: torajmohammadi@iust.ac.ir

    2015-08-15

    Highlights: • CNTs–mullite composite was prepared via chemical vapor deposition (CVD) method. • The prepared composite was modified with concentrated nitric acid and chitosan. • The modified CNTs–mullite composites were used as novel adsorbents. • Copper ion removal from water by the prepared adsorbents was performed. • Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. - Abstract: Carbon nanotubes–mullite composite was synthesized by direct growth of carbon nanotubes on mullite particles via chemical vapor deposition method using cyclohexanol and ferrocene as carbon precursor and catalyst, respectively. The carbon nanotubes–mullite composite was oxidized with concentrated nitric acid and functionalized with chitosan and then used as a novel adsorbent for copper ions removal from water. The results demonstrated that modification with concentrated nitric acid and chitosan improves copper ions adsorption capacity of the prepared composite, significantly. Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. The carbon nanotubes growth on mullite particles to form the carbon nanotubes–mullite composite with further modification is an inherently safe approach for many promising environmental applications to avoid some concerns regarding environment, health and safety. It was found that the modified carbon nanotubes–mullite composite can be considered as an excellent adsorbent for copper ions removal from water.

  4. Measurement of labile copper in wine by medium exchange stripping potentiometry utilising screen printed carbon electrodes.

    Science.gov (United States)

    Clark, Andrew C; Kontoudakis, Nikolaos; Barril, Celia; Schmidtke, Leigh M; Scollary, Geoffrey R

    2016-07-01

    The presence of copper in wine is known to impact the reductive, oxidative and colloidal stability of wine, and techniques enabling measurement of different forms of copper in wine are of particular interest in understanding these spoilage processes. Electrochemical stripping techniques developed to date require significant pretreatment of wine, potentially disturbing the copper binding equilibria. A thin mercury film on a screen printed carbon electrode was utilised in a flow system for the direct analysis of labile copper in red and white wine by constant current stripping potentiometry with medium exchange. Under the optimised conditions, including an enrichment time of 500s and constant current of 1.0μA, the response range was linear from 0.015 to 0.200mg/L. The analysis of 52 red and white wines showed that this technique generally provided lower labile copper concentrations than reported for batch measurement by related techniques. Studies in a model system and in finished wines showed that the copper sulfide was not measured as labile copper, and that loss of hydrogen sulfide via volatilisation induced an increase in labile copper within the model wine system.

  5. Thermal conductivity, electrical conductivity and specific heat of copper-carbon fiber composite

    Science.gov (United States)

    Kuniya, Keiichi; Arakawa, Hideo; Kanai, Tsuneyuki; Chiba, Akio

    1988-01-01

    A new material of copper/carbon fiber composite is developed which retains the properties of copper, i.e., its excellent electrical and thermal conductivity, and the property of carbon, i.e., a small thermal expansion coefficient. These properties of the composite are adjustable within a certain range by changing the volume and/or the orientation of the carbon fibers. The effects of carbon fiber volume and arrangement changes on the thermal and electrical conductivity, and specific heat of the composite are studied. Results obtained are as follows: the thermal and electrical conductivity of the composite decrease as the volume of the carbon fiber increases, and were influenced by the fiber orientation. The results are predictable from a careful application of the rule of mixtures for composites. The specific heat of the composite was dependent, not on fiber orientation, but on fiber volume. In the thermal fatigue tests, no degradation in the electrical conductivity of this composite was observed.

  6. Effects of Two Purification Pretreatments on Electroless Copper Coating over Single-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Zhong Zheng

    2014-01-01

    Full Text Available To achieve the reinforcement of copper matrix composite by single-walled carbon nanotubes, a three-step-refluxing purification of carbon nanotubes sample with HNO3-NaOH-HCl was proposed and demonstrated. A previously reported purification process using an electromagnetic stirring with H2O2/HCl mixture was also repeated. Then, the purified carbon nanotubes were coated with copper by the same electroless plating process. At the end, the effects of the method on carbon nanotubes themselves and on copper coating were determined by transmission electron microscope spectroscopy, scanning electron microscope spectroscopy, X-ray diffractometry, thermogravimetric analysis, Fourier transformed infrared spectroscopy, and energy dispersive spectrometry. It was clearly confirmed that both of the two processes could remove most of iron catalyst particles and carbonaceous impurities without significant damage to carbon nanotubes. The thermal stability of the sample purified by H2O2/HCl treatment was slightly higher than that purified by HNO3-NaOH-HCl treatment. Nevertheless, the purification by HNO3-NaOH-HCl treatment was more effective for carboxyl functionalization on nanotubes than that by H2O2/HCl treatment. The Cu-coating on carbon nanotubes purified by both purification processes was complete, homogenous, and continuous. However, the Cu-coating on carbon nanotubes purified by H2O2/HCl was oxidized more seriously than those on carbon nanotubes purified by HNO3-NaOH-HCl treatment.

  7. Microstructure and properties of pure iron/copper composite cladding layers on carbon steel

    Institute of Scientific and Technical Information of China (English)

    Long Wan; Yong-xian Huang; Shi-xiong L; Ti-fang Huang; Zong-liang L

    2016-01-01

    In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses of the composite cladding layers. Iron liq-uid–solid-phase zones were formed at copper/steel and iron interfaces because of the melting of the steel substrate and iron. Iron concentrated in the copper cladding layer was observed to exhibit belt, globule, and dendrite morphologies. The appearance of iron-rich globules indicated the occurrence of liquid phase separation (LPS) prior to solidification, and iron-rich dendrites crystallized without the occurrence of LPS. The maximum microhardness of the iron/steel interface was lower than that of the copper/steel interface because of the diffusion of elemental carbon. All samples fractured in the cladding layers. Because of a relatively lower strength of the copper layer, a short plateau region ap-peared when shear movement was from copper to iron.

  8. Dissolved organic carbon reduces the toxicity of copper to germlings of the macroalgae, Fucus vesiculosus.

    Science.gov (United States)

    Brooks, Steven J; Bolam, Thi; Tolhurst, Laura; Bassett, Janice; La Roche, Jay; Waldock, Mike; Barry, Jon; Thomas, Kevin V

    2008-05-01

    This study investigates the effects of waterborne copper exposure on germling growth in chemically defined seawater. Germlings of the macroalgae, Fucus vesiculosus were exposed to a range of copper and dissolved organic carbon (DOC as humic acid) concentrations over 14 days. Germling growth was found to be a sensitive indicator of copper exposure with total copper (TCu) and labile copper (LCu) EC(50) values of approximately 40 and 20 microg/L, respectively, in the absence of added DOC. The addition of DOC into the exposure media provided germlings with protection against copper toxicity, with an increased TCu EC(50) value of 117.3 microg/L at a corrected DOC (cDOC from humic acid only) concentration of 2.03 mg/L. The LCu EC(50) was not affected by a cDOC concentration of 1.65 mg/L or less, suggesting that the LCu concentration not the TCu concentration was responsible for inhibiting germling growth. However, at a cDOC concentration of approximately 2mg/L an increase in the LCu EC(50) suggests that the LCu concentration may play a role in the overall toxicity to the germlings. This is contrary to current understanding of aquatic copper toxicity and possible explanations for this are discussed.

  9. INFLUENCE OF THERMAL CYCLING ON MICROSTRUCTURE AND THERMAL EXPANSION OF CARBON FIBRES/COPPER COMPOSITES

    Directory of Open Access Journals (Sweden)

    Pavol Štefánik

    2009-06-01

    Full Text Available The preparation of copper matrix reinforced by high modulus carbon fibres (Thornel K1100 as well as the microstructure and dilatation changes during thermocycling is presented.Unidirectional composites with two types of matrix - pure copper and/or copper alloy with 0.2 wt. % of chromium - were thermally cycled between 30-600 °C three times.The composite with pure Cu exhibited larger voids and weak interfacial bonding. Due to the chemical reaction with K1100 fibres a reactive interfacial bonding has been formed. During thermocycling the hysteresis, but no large disintegration was observed. The coefficients of thermal expansion (CTEs strongly depend on fibre orientation. In direction parallel to the fibre orientation in the temperature range of 220-500°C CTEs were very low (0.7-1.0x10-6/K, but in perpendicular direction the CTEs were higher than that of pure copper.

  10. Expeditious low-temperature sintering of copper nanoparticles with thin defective carbon shells

    Science.gov (United States)

    Kim, Changkyu; Lee, Gyoungja; Rhee, Changkyu; Lee, Minku

    2015-04-01

    The realization of air-stable nanoparticles, well-formulated nanoinks, and conductive patterns based on copper is a great challenge in low-cost and large-area flexible printed electronics. This work reports the synthesis of a conductively interconnected copper structure via thermal sintering of copper inks at a low temperature for a short period of time, with the help of thin defective carbon shells coated onto the copper nanoparticles. Air-stable copper/carbon core/shell nanoparticles (typical size ~23 nm, shell thickness ~1.0 nm) are prepared by means of an electric explosion of wires. Gaseous oxidation of the carbon shells with a defective structure occurs at 180 °C, impacting the choice of organic solvents as well as the sintering conditions to create a crucial neck formation. Isothermal oxidation and reduction treatment at 200 °C for only about 10 min yields an oxide-free copper network structure with an electrical resistivity of 25.1 μΩ cm (14.0 μΩ cm at 250 °C). Finally, conductive copper line patterns are achieved down to a 50 μm width with an excellent printing resolution (standard deviation ~4.0%) onto a polyimide substrate using screen printing of the optimized inks.The realization of air-stable nanoparticles, well-formulated nanoinks, and conductive patterns based on copper is a great challenge in low-cost and large-area flexible printed electronics. This work reports the synthesis of a conductively interconnected copper structure via thermal sintering of copper inks at a low temperature for a short period of time, with the help of thin defective carbon shells coated onto the copper nanoparticles. Air-stable copper/carbon core/shell nanoparticles (typical size ~23 nm, shell thickness ~1.0 nm) are prepared by means of an electric explosion of wires. Gaseous oxidation of the carbon shells with a defective structure occurs at 180 °C, impacting the choice of organic solvents as well as the sintering conditions to create a crucial neck formation

  11. An infrared spectroscopic study of the adsorption of carbon monoxide on silica-supported copper oxide

    NARCIS (Netherlands)

    Jong, K.P. de; Geus, John W.; Joziasse, J.

    1980-01-01

    Adsorption of carbon monoxide at room temperature (0.1–50 Torr) on silica-supported copper oxide was studied by infrared spectroscopy. Catalysts were prepared by deposition-precipitation or impregnation. After calcination two types of adsorbed CO were identified showing absorption bands at 2136 ± 3

  12. Analytical applications of a carbon nanotubes composite modified with copper microparticles as detector in flow systems.

    Science.gov (United States)

    Arribas, Alberto Sánchez; Bermejo, Esperanza; Chicharro, Manuel; Zapardiel, Antonio; Luque, Guillermina L; Ferreyra, Nancy F; Rivas, Gustavo A

    2006-09-08

    In this work we report on the successful use of a composite prepared by dispersion of multi-wall carbon nanotubes (1-5 microm length, 20-50 nm diameter) and copper microparticles within mineral oil as detector for amino acids quantification in flow injection analysis and capillary electrophoresis. The resulting electrode displays a highly sensitive amperometric detection of amino acids, based on the copper dissolution facilitated by the strong activity of amino acids as ligands of Cu(II). The sensor makes possible the detection of amino acids, electroactive or not, at very low potentials (0.000 V) and physiological pH. A correlation between the sensitivity for the amino acids and the amount of copper within the composite is observed, demonstrating the importance of the metal in the sensor response. The best analytical performance is obtained for the electrode containing 12.0% (w/w) copper. The excellent results obtained with the carbon nanotube paste electrodes containing copper (CNTPE-Cu) as detector in flow systems makes them an interesting alternative for further analytical applications involving different bioanalytes.

  13. Effect of reduction treatment on copper modified activated carbons on NO(x) adsorption at room temperature.

    Science.gov (United States)

    Levasseur, Benoit; Gonzalez-Lopez, Eugene; Rossin, Joseph A; Bandosz, Teresa J

    2011-05-01

    Activated carbon was impregnated with copper salt and then exposed to reductive environment using hydrazine hydrate or heat treatment under nitrogen at 925 °C. On the obtained samples, adsorption of NO(2) was carried out at dynamic conditions at ambient temperature. The adsorbents before and after exposure to nitrogen dioxide were characterized by X-ray diffraction (XRD), thermal analysis, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS), N(2)-sorption at -196 °C, and potentiometric titration. Copper loading improved the adsorption capacity of NO(2) as well as the retention of NO formed in the process of NO(2) reduction on the carbon surface. That improvement is linked to the presence of copper metal and its high dispersion on the surface. Even though both reduction methods lead to the reduction of copper, different reactions with the carbon surface take place. Heat treatment results in a significant percentage of metallic copper and a reduction of oxygen functional groups of the carbon matrix, whereas hydrazine, besides reduction of copper, leads to an incorporation of nitrogen. The results suggest that NO(2) mainly is converted to copper nitrates although the possibility to its reduction to N(2) is not ruled out. A high capacity on hydrazine treated samples is linked to the high dispersion of metallic copper on the surface of this carbon.

  14. Corrosion of carbon steel, zinc and copper by air pollution in Chongqing

    Institute of Scientific and Technical Information of China (English)

    YE Di; ZHAO Da-wei; CHEN Gang-cai; ZHANG Dong-bao

    2007-01-01

    This paper presents the research on the atmospheric corrosion rates of carbon steel, zinc and copper in Chongqing, which was a corrosion subprogram of an international project, Regional Air Pollution in Developing Countries. We performed field exposure tests of carbon steel, zinc and copper at an urban site Guanyinqiao and a rural site Tieshanping inChongqing, then used grey relational analysis, based on the database of the whole corrosion project, to determine the order of the effect of environmental factors on corrosion rates of tested metals, and established dose-response functions for these three metals. The results showed that the two crucial agents of acidic environment, SO2 and H+, were common factors that contributed most to the corrosion of the tested metals. The established dose-response functions for outdoor carbon steel and zinc are proved applicable to use in Chongqing, but the function for copper needs further modifying. We employed these dose-response functions and general environmental data to elaborate the maps of corrosion rate respectively of carbon steel and zinc by geological information system (GIS) technique which help to identify areas of high corrosion damage risk. An acceptable annual average SO2 level of 21 μg/m3 for carbon steel and that of 61 μg/m3 for zinc are also put forward to control the air pollution impact on atmospheric corrosion in Chongqing urban areas.

  15. Mechanical synthesis of copper-carbon nanocomposites: Structural changes, strengthening and thermal stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, D., E-mail: daniela.nunes@ist.utl.pt [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); LNEG, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); ICEMS, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Livramento, V. [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); LNEG, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); Mateus, R. [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Correia, J.B. [LNEG, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); Alves, L.C. [ITN, Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Vilarigues, M. [Departamento de Conservacao e Restauro e R and D Unit Vidro e da Ceramica Para as Artes, FCT-UNL, Quinta da Torre, 2829-516 Caparica (Portugal); Carvalho, P.A. [ICEMS, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Departamento de Bioengenharia, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2011-11-15

    Highlights: {yields} The study characterized Cu-nanodiamond (Cu-nD) and Cu-graphite (Cu-G) composites. {yields} Preservation of nD crystalline structure during high-energy milling was demonstrated. {yields} Higher refinement of matrix in Cu-nD comparing to Cu-G is due to a milling mechanism. {yields} Remarkable thermal stability and microhardness have been achieved in Cu-nD and Cu-G. {yields} Strengthening resulted mainly from grain refinement and second-phase reinforcement. - Abstract: Processing of copper-carbon nanocomposites by mechanical synthesis poses specific challenges as carbon phases are prone to amorphization and exhibit an intrinsically difficult bonding with copper. The present work investigates Cu-nanodiamond (Cu-nD) and Cu-graphite (Cu-G) composites produced by mechanical synthesis and subsequent heat treatments. Transmission electron microscopy observations showed homogeneous particle distributions and intimate bonding between the metallic matrix and the carbon phases. Ring diffraction patterns of chemically extracted carbon phases demonstrated that milled nanodiamond preserved crystallinity, while an essentially amorphous nature could be inferred for milled graphite. Raman spectra confirmed that nanodiamond particles remained essentially unaffected by the mechanical synthesis, whereas the bands of milled graphite were significantly changed into the typical amorphous carbon fingerprint. Particle-induced X-ray emission spectroscopy showed that the total contamination originating from the milling media remained below 0.7 wt.%. The Cu-nanodiamond composite exhibited remarkable microhardness and microstructural thermal stability when compared with pure nanostructured copper.

  16. Electrochemical Reduction of Carbon Dioxide over CNT-Supported Nanoscale Copper Electrocatalysts

    Directory of Open Access Journals (Sweden)

    Sk. Safdar Hossain

    2014-01-01

    Full Text Available This paper presents the experimental investigation of copper loaded carbon nanotubes (CNTs electrocatalysts for the electrochemical reduction of carbon dioxide. The electrocatalysts were synthesized by homogeneous deposition precipitation method (HDP using urea as precipitating agent. The prepared catalysts were characterized by TEM, SEM, XRD, XPS, BET, and FTIR for their morphology and structure. Characterization results confirm the deposition of Cu nanoparticles (3–60 nm on CNTs. Linear sweep voltammetry (LSV and chronoamperometry (CA were used to investigate the activity of the as-prepared catalysts for the electrochemical reduction of carbon dioxide. The electrocatalysts reduced CO2 with high current density in the potential range 0~−3 V versus SCE (standard calomel electrode. Among all catalysts tested, 20 wt. % copper loaded CNTs showed maximum activity. Gas chromatograph with TCD was used to analyze liquid phase composition. The faradaic efficiency for methanol formation was estimated to be 38.5%.

  17. Bimetallic ruthenium-copper nanoparticles embedded in mesoporous carbon as an effective hydrogenation catalyst.

    Science.gov (United States)

    Liu, Jiajia; Zhang, Li Li; Zhang, Jiatao; Liu, Tao; Zhao, X S

    2013-11-21

    Bimetallic ruthenium-copper nanoparticles embedded in the pore walls of mesoporous carbon were prepared via a template route and evaluated in terms of catalytic properties in D-glucose hydrogenation. The existence of bimetallic entities was supported by Ru L3-edge and Cu K-edge X-ray absorption results. The hydrogen spillover effect of the bimetallic catalyst on the hydrogenation reaction was evidenced by the results of both hydrogen and carbon monoxide chemisorptions. The bimetallic catalyst displayed a higher catalytic activity than the single-metal catalysts prepared using the same approach, namely ruthenium or copper nanoparticles embedded in the pore walls of mesoporous carbon. This improvement was due to the changes in the geometric and electronic structures of the bimetallic catalyst because of the presence of the second metal.

  18. Large pore volume mesoporous copper particles and scaffold microporous carbon material obtained from an inorganic-organic nanohybrid material, copper-succinate-layered hydroxide.

    Science.gov (United States)

    Ghotbi, Mohammad Yeganeh; Bagheri, Narjes; Sadrnezhaad, S K

    2011-10-01

    Copper-succinate-layered hydroxide (CSLH), a new nanohybrid material, was synthesized as an inorganic-organic nanohybrid, in which organic moiety was intercalated between the layers of a single cation layered material, copper hydroxide nitrate. Microporous scaffold carbon material was obtained by thermal decomposition of the nanohybrid at 500 °C under argon atmosphere followed by acid washing process. Furthermore, the heat-treated product of the nanohybrid at 600 °C was ultrafine mesoporous metallic copper particles. The results of this study confirmed the great potential of CSLH to produce the carbon material with large surface area (580 m(2)/g) and high pore volume copper powder (2.04 cm(3)/g).

  19. Carbon mediated reduction of silicon dioxide and growth of copper silicide particles in uniform width channels

    DEFF Research Database (Denmark)

    Pizzocchero, Filippo; Bøggild, Peter; Booth, Tim

    2013-01-01

    channels, which are aligned with the intersections of the (100) surface of the wafer and the {110} planes on an oxidized silicon wafer, as well as endotaxial copper silicide nanoparticles within the wafer bulk. We apply energy dispersive x-ray spectroscopy, in combination with scanning and transmission......We show that surface arc-discharge deposited carbon plays a critical intermediary role in the breakdown of thermally grown oxide diffusion barriers of 90 nm on a silicon wafer at 1035°C in an Ar/H2 atmosphere, resulting in the formation of epitaxial copper silicide particles in ≈ 10 μm wide...

  20. Towards understanding the carbon trapping mechanism in copper by investigating the carbon-vacancy interaction

    Institute of Scientific and Technical Information of China (English)

    Zhou Hong-Bo; Jin Shuo

    2013-01-01

    We propose a vacancy trapping mechanism for carbon-vacancy (C-V) complex formation in copper (Cu) according to the first-principles calculations of the energetics and kinetics of C-V interaction.Vacancy reduces charge density in its vicinity to induce C nucleation.A monovacancy is capable of trapping as many as four C atoms to form CnV (n =1,2,3,4)complexes.A single C atom prefers to interact with neighboring Cu at a vacancy with a trapping energy of-0.21 eV.With multiple C atoms added,they are preferred to bind with each other to form covalent-like bonds despite of the metallic Cu environment.For the CnV complexes,C2V is the major one due to its lowest average trapping energy (1.31 eV).Kinetically,the formation of the CnV complexes can be ascribed to the vacancy mechanism due to the lower activation energy barrier and the larger diffusion coefficient of vacancy than those of the interstitial C.

  1. Applying of copper(ІІ carbonate as a decrease mode of a fire hazard of epoxy-amine composites

    Directory of Open Access Journals (Sweden)

    Олена Іванівна Лавренюк

    2016-05-01

    Full Text Available Being based on data about electronic and crystal structure of copper salts, their using perspective for fire retardants of epoxy-amine composites have been foreseen. Epoxy-amine composites modified by copper compounds, in particular, by copper(ІІ carbonate have been elaborated. Influence of fire retardant onto processes of thermal-oxidative decomposition of epoxy-amine composites and their fire hazard has been studied

  2. Modified activated carbons with amino groups and their copper adsorption properties in aqueous solution

    Institute of Scientific and Technical Information of China (English)

    Mohammad Hassan Mahaninia; Paria Rahimian; Tahereh Kaghazchi

    2015-01-01

    Activated carbons were prepared by two chemical methods and the adsorption of Cu (II) on activated carbons from aqueous solution containing amino groups was studied. The first method involved the chlorination of activated carbon following by substitution of chloride groups with amino groups, and the second involved the nitrilation of activated carbon with reduction of nitro groups to amino groups. Resultant activated carbons were characterized in terms of porous structure, elemental analysis, FTIR spectroscopy, XPS, Boehm titration, and pHzpc. Kinetic and equilibrium tests were performed for copper adsorption in the batch mode. Also, adsorption mechanism and effect of pH on the adsorption of Cu (II) ions were discussed. Adsorption study shows enhanced adsorption for copper on the modified activated carbons, mainly by the presence of amino groups, and the Freundlich model is applicable for the activated carbons. It is suggested that binding of nitrogen atoms with Cu (II) ions is stronger than that with H+ions due to relatively higher divalent charge or stronger electrostatic force.

  3. Copper induced hollow carbon nanospheres by arc discharge method: controlled synthesis and formation mechanism

    Science.gov (United States)

    Hu, Rui; Alexandru Ciolan, Mihai; Wang, Xiangke; Nagatsu, Masaaki

    2016-08-01

    Hollow carbon nanospheres with controlled morphologies were synthesized via the copper-carbon direct current arc discharge method by alternating the concentrations of methane in the reactant gas mixture. A self-healing process to keep the structural integrity of encapsulated graphitic shells was evolved gradually by adding methane gas from 0% to 20%. The outer part of the coated layers expanded and hollow nanospheres grew to be large fluffy ones with high methane concentrations from 30% to 50%. A self-repairing function by the reattachment of broken graphitic layers initiated from near-electrode space to distance was also distinctly exhibited. By comparing several comparable metals (e.g. copper, silver, gold, zinc, iron and nickel)-carbon arc discharge products, a catalytic carbon-encapsulation mechanism combined with a core-escaping process has been proposed. Specifically, on the basis of the experimental results, copper could be applied as a unique model for both the catalysis of graphitic encapsulation and as an adequate template for the formation of hollow nanostructures.

  4. Enhanced electrochemical methanation of carbon dioxide with a dispersible nanoscale copper catalyst.

    Science.gov (United States)

    Manthiram, Karthish; Beberwyck, Brandon J; Alivisatos, A Paul

    2014-09-24

    Although the vast majority of hydrocarbon fuels and products are presently derived from petroleum, there is much interest in the development of routes for synthesizing these same products by hydrogenating CO2. The simplest hydrocarbon target is methane, which can utilize existing infrastructure for natural gas storage, distribution, and consumption. Electrochemical methods for methanizing CO2 currently suffer from a combination of low activities and poor selectivities. We demonstrate that copper nanoparticles supported on glassy carbon (n-Cu/C) achieve up to 4 times greater methanation current densities compared to high-purity copper foil electrodes. The n-Cu/C electrocatalyst also exhibits an average Faradaic efficiency for methanation of 80% during extended electrolysis, the highest Faradaic efficiency for room-temperature methanation reported to date. We find that the level of copper catalyst loading on the glassy carbon support has an enormous impact on the morphology of the copper under catalytic conditions and the resulting Faradaic efficiency for methane. The improved activity and Faradaic efficiency for methanation involves a mechanism that is distinct from what is generally thought to occur on copper foils. Electrochemical data indicate that the early steps of methanation on n-Cu/C involve a pre-equilibrium one-electron transfer to CO2 to form an adsorbed radical, followed by a rate-limiting non-electrochemical step in which the adsorbed CO2 radical reacts with a second CO2 molecule from solution. These nanoscale copper electrocatalysts represent a first step toward the preparation of practical methanation catalysts that can be incorporated into membrane-electrode assemblies in electrolyzers.

  5. In situ investigation of morphological and phase changes during thermal annealing and oxidation of carbon-encapsulated copper nanoparticles

    Science.gov (United States)

    Bokhonov, B. B.; Novopashin, S. A.

    2010-10-01

    In situ electron microscope and X-ray investigations of the morphological and phase characteristics of copper nanoparticles encapsulated in a carbon shell were carried out. It was found that oxidation of the copper nanoparticles starts at a temperature of 200 °C. The formation of oxide phases occurs on the surface of the carbon shells, with the Cu2O phase appearing first followed by the formation of the CuO phase. Upon heating to just below its melting point, the copper sublimes resulting in the formation of hollow carbon nanocapsules. Treatment of the initial or oxidized encapsulated copper nanoparticles with nitric acid and annealing can be used to obtain hollow carbon nanocapsules.

  6. In situ investigation of morphological and phase changes during thermal annealing and oxidation of carbon-encapsulated copper nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bokhonov, B. B., E-mail: bokhonov@solid.nsc.r [Russian Academy Sciences, Laboratory of Non-Equilibrium Processes, Institute of Solid State Chemistry, Siberian Branch (Russian Federation); Novopashin, S. A. [Russian Academy Sciences, Department of Rarefied Gases, Institute of Thermophysics, Siberian Branch (Russian Federation)

    2010-10-15

    In situ electron microscope and X-ray investigations of the morphological and phase characteristics of copper nanoparticles encapsulated in a carbon shell were carried out. It was found that oxidation of the copper nanoparticles starts at a temperature of 200 {sup o}C. The formation of oxide phases occurs on the surface of the carbon shells, with the Cu{sub 2}O phase appearing first followed by the formation of the CuO phase. Upon heating to just below its melting point, the copper sublimes resulting in the formation of hollow carbon nanocapsules. Treatment of the initial or oxidized encapsulated copper nanoparticles with nitric acid and annealing can be used to obtain hollow carbon nanocapsules.

  7. The synthesis of a copper/multi-walled carbon nanotube hybrid nanowire in a microfluidic reactor

    Science.gov (United States)

    Peng, Yitian; Chen, Quanfang

    2009-06-01

    Metallic nanowires are promising as components in nanoscale systems including nanoelectronics. However, the application of nanowires made of a single material is limited by the properties of the material used. We report here an effort to fabricate a hybrid copper-coated carbon nanotube (CNT)—Cu/CNT nanowire, using a microfluidic reactor. The fabrication of copper/multi-walled carbon nanotube (MWCNT) hybrid nanowires was realized by an electroless copper deposition technique in which MWCNT templates and an electrolyte were introduced separately into the microfluidic reactor. The morphology and structure of the Cu/MWCNT hybrid nanowire were studied by means of transmission electron microscopy (TEM), selected-area electron diffraction (SAED), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX), as well as XRD. Results reveal that the fabricated Cu/MWCNT hybrid nanowires are continuously covered by crystallized copper with a preferred crystal orientation along the (111) planes in the radial direction of the MWCNTs. These structural properties are attributed to the unique reaction environment including laminar flow and diffusion-controlled reaction.

  8. A double-walled carbon nanotube oscillator encapsulating a copper nanowire

    Science.gov (United States)

    Kang, Jeong Won; Jiang, Qing; Hwang, Ho Jung

    2006-11-01

    A double-walled carbon nanotube (CNT) oscillator encapsulating a copper nanowire has been investigated using molecular dynamics simulations. Our simulation results show that the excess energy due to the interactions between the copper nanowire and the outer CNT were around 1% of the excess of van der Waals energy between the inner and the outer CNTs. The classical oscillation theory and the theory given by Zheng et al (2002 Phys. Rev. Lett. 88 045503) provide a fairly good estimate of the mass-dependent frequency of a CNT oscillator encapsulating a metal nanowire. The nanotube oscillator encapsulating a metal nanowire is found to be more dependent on the encapsulated metal mass than the metal-carbon interaction.

  9. Immobilization and direct electrochemistry of copper-containing enzymes on active carbon

    Institute of Scientific and Technical Information of China (English)

    SUN Dongmei; CAI Chenxin; XING Wei; LU Tianhong

    2004-01-01

    Two typical and important copper-containing enzymes, laccase (Lac) and tyrosinase (Tyr), have been immobilized on the surface of active carbon with simple adsorption method. The cyclic voltammetric results indicated that the active carbon could promote the direct electron transfer of both Lac and Tyr and a pair of well-defined and nearly symmetric redox peaks appeared on the cyclic voltammograms of Lac or Tyr with the formal potential, E0′, independent on the scan rate. The further experimental results showed that the immobilized copper-containing oxidase displayed an excellent electrocatalytic activity to the electrochemical reduction of O2. The immobilization method presented here has several advantages, such as simplicity, easy to operation and keeping good activity of enzyme etc., and could be further used to study the direct electrochemistry of other redox proteins and enzymes and fabricate the catalysts for biofuel cell.

  10. Nanostructured Multifilamentary Carbon-Copper Composites: Fabrication, Microstructural Characterization, and Properties

    Directory of Open Access Journals (Sweden)

    Evarice Yama Nzoma

    2012-01-01

    Full Text Available This work is part of research on the emerging techniques to produce bulk nanostructured composites materials by severe plastic deformation and their characterization. Based on the Levi work, we present a new method to synthesize a composite wire-containing carbon-nanosized filaments (graphite and C60 fullerenes embedded in a copper matrix. The originality of this process is using powder media as fiber. Microstructures and electrical, mechanical, and thermal properties are presented.

  11. Preconcentration and electroanalysis of copper at glassy carbon electrode modified with poly(2-aminothiazole)

    OpenAIRE

    Çiftçi, Hakan; Testereci, Hasan Nur; Öktem, Zeki

    2011-01-01

    Conducting poly(2-aminothiazole), PAT, was synthesized in acetonitrile with tetrabutylammonium tetrafluoroborate, TBAFB, as supporting electrolyte via constant potential electrolysis, CPE. Glassy carbon, GC, electrode was modified by immersing the electrode in a DMSO solution of PAT. Preconcentration of copper on polymer matrix was carried out at -0.7 V. The effects of preconcentration time and pH and Cu(II) concentration of the preconcentration solution on the stripping peak current of coppe...

  12. Field emission response from multi-walled carbon nanotubes grown on electrochemically engineered copper foil

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Amit Kumar; Jain, Vaibhav [Nanomaterials and Applications Lab., Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India); Saini, Krishna [Nanomaterials and Applications Lab., Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India); Centre of Excellence: Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India); Lahiri, Indranil, E-mail: indrafmt@iitr.ac.in [Nanomaterials and Applications Lab., Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India); Centre of Excellence: Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand (India)

    2017-02-01

    Exciting properties of carbon nanotube has proven it to be a promising candidate for field emission applications, if its processing cost can be reduced effectively. In this research, a new electrochemical technique is proposed for growing carbon nanotubes in selective areas by thermal chemical vapour deposition. In this process, electrochemical processing is used to create localized pits and deposition of catalysts, which act as roots to support growth and alignment of the CNTs on copper substrate. CNTs grown thus were characterized and studied using scanning electron microscope, transmission electron microscope and Raman spectroscopy, elucidating presence of multiwall carbon nanotubes (MWCNT). These CNT emitters have comparatively lower turn-on field and higher field enhancement factor. - Highlights: • Electrochemical pitting for localized carbon nanotube growth is proposed. • Electrochemical pitting method shows patterning effect on the substrate. • Size and density of pits depend on voltage, pH and temperature. • CNTs thus grown shows good field emission response.

  13. Barium carbonate as an agent to improve the electrical properties of neodymium-barium-copper system at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, J.P. [Post-Graduate Program in Chemical Engineering, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, 88040-900 (Brazil); Duarte, G.W. [Post-Graduate Program in Chemical Engineering, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, 88040-900 (Brazil); Research Group in Technology and Information, Centro Universitário Barriga Verde (UNIBAVE), Santa Catarina, SC (Brazil); Caldart, C. [Post-Graduate Program in Science and Materials Engineering, Universidade do Extremo Sul Catarinense (UNESC), Criciúma, SC, 88806-000 (Brazil); Kniess, C.T. [Post-Graduate Program in Professional Master in Management, Universidade Nove de Julho, São Paulo, SP (Brazil); Montedo, O.R.K.; Rocha, M.R. [Post-Graduate Program in Science and Materials Engineering, Universidade do Extremo Sul Catarinense (UNESC), Criciúma, SC, 88806-000 (Brazil); Riella, H.G. [Post-Graduate Program in Chemical Engineering, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, 88040-900 (Brazil); Fiori, M.A., E-mail: fiori@unochapeco.edu.br [Post-Graduate Program in Environmental Science, Universidade Comunitária da Região de Chapecó (UNOCHAPECÓ), Chapecó, SC, 89809-000 (Brazil); Post-Graduate Program in Technology and Management of the Innovation, Universidade Comunitária da Região de Chapecó (UNOCHAPECÓ), Chapecó, SC, 89809-000 (Brazil)

    2015-11-15

    Specialized ceramics are manufactured under special conditions and contain specific elements. They possess unique electrical and thermal properties and are frequently used by the electronics industry. Ceramics containing neodymium-barium-copper (NBC) exhibit high conductivities at low temperatures. NBC-based ceramics are typically combined with oxides, i.e., NBCo produced from neodymium oxide, barium oxide and copper oxide. This study presents NBC ceramics that were produced with barium carbonate, copper oxide and neodymium oxide (NBCa) as starting materials. These ceramics have good electrical conductivities at room temperature. Their conductivities are temperature dependent and related to the starting amount of barium carbonate (w%). - Highlights: • The new crystalline structure were obtained due presence of the barium carbonate. • The NBCa compound has excellent electrical conductivity at room temperature. • The grain crystalline morphology was modified by presence of the barium carbonate. • New Phases α and β were introduced by carbonate barium in the NBC compound.

  14. Co-sputtering C-Cu thin film synthesis: microstructural study of copper precipitates encapsulated into a carbon matrix

    Science.gov (United States)

    Cabioc'h, Thierry; Naudon, Andre; Jaouen, Michel; Thiaudiere, Dominique; Babonneau, David

    1999-03-01

    Co-sputtered C-Cu thin film depositions have been performed in the temperature range 80-873 K, the atomic carbon concentration varying from 16% to 96% . To characterize the microstructure of the C-Cu thin films, transmission electron microscopy, extended X-ray absorption fine structure and grazing incidence small angle X-ray scattering experiments have been used. During the deposition process, a demixing occurs of the carbon and copper species due to their very low solubilities that leads to the formation of nanometric copper precipitates homogeneously distributed in a more or less graphitic matrix. These precipitates have an elongated shape in the direction of the thin film growth. When the deposition was performed at 273 K for copper atomic concentrations CCu > 55% , as well as for all thin films synthesized at 573 K whatever the CCu value, the formation of graphene layers parallel to the surface of the copper precipitates was observed so that an encapsulation of the Cu aggregates in carbon cages occurs. We propose that surface diffusion of the different species occurring during the deposition process leads to the demixing of carbon and copper. Thus, we suggest that the copper acts as a catalyst for graphitization of carbon to explain the formation of such structures at temperatures as low as those used in these experiments.

  15. Co-precipitation of copper and niobium carbide in a low carbon steel

    Science.gov (United States)

    Gagliano, Michael Scott

    Co-precipitation of niobium carbide and body-centered cubic (BCC) copper in ferrite was investigated as a high strength, low carbon, chromium-free alternative to conventional high performance structural steels that rely on a tempered martensitic microstructure. Theoretical nucleation and growth rate models for BCC copper and niobium carbide were constructed using calculated thermodynamic driving forces in conjunction with classical theories for the homogeneous nucleation and subsequent growth of coherent, spherical precipitates. The maximum calculated nucleation and growth rates for niobium carbide were found to be 1.0 x 106 nuclei/cm3s at 666°C and 1.0 nm/s at 836°C, respectively, for an austenitizing temperature of 1170°C. For BCC copper in ferrite, the maximum calculated nucleation and growth rates were determined to be 8.0 x 1015 nuclei/cm 3s at 612°C and 0.038 nm/s at 682°C, respectively, for all austenitizing temperatures. Three-dimensional atom probe (3DAP) microscopy revealed the presence of nano-scale BCC copper clusters in approximately the same number density predicted by the theoretical nucleation model. Using an experimentally determined "effective" activation energy for copper in iron, the normalized theoretical nucleation rate curve compared very well with the normalized hardness response after 5 minutes of aging and effectively described the experimental short-time aging behavior of a low carbon, niobium bearing steel. The size and morphological evolution as well as the growth and coarsening behavior of copper precipitates were investigated through conventional TEM during isothermal direct aging at 550°C for a niobium and niobium-free steel. Although niobium carbide precipitation was not characterized, niobium additions provided increased hardness upon direct aging and showed a much higher resistance to overaging, than a niobium-free steel, for long isothermal aging times. In both steels for aging times up to five hours, both 9R type and BCC

  16. Improved field emission performance of carbon nanotube by introducing copper metallic particles

    Directory of Open Access Journals (Sweden)

    Chen Yiren

    2011-01-01

    Full Text Available Abstract To improve the field emission performance of carbon nanotubes (CNTs, a simple and low-cost method was adopted in this article. We introduced copper particles for decorating the CNTs so as to form copper particle-CNT composites. The composites were fabricated by electrophoretic deposition technique which produced copper metallic particles localized on the outer wall of CNTs and deposited them onto indium tin oxide (ITO electrode. The results showed that the conductivity increased from 10-5 to 4 × 10-5 S while the turn-on field was reduced from 3.4 to 2.2 V/μm. Moreover, the field emission current tended to be undiminished after continuous emission for 24 h. The reasons were summarized that introducing copper metallic particles to decorate CNTs could increase the surface roughness of the CNTs which was beneficial to field emission, restrain field emission current from saturating when the applied electric field was above the critical field. In addition, it could also improve the electrical contact by increasing the contact area between CNT and ITO electrode that was beneficial to the electron transport and avoided instable electron emission caused by thermal injury of CNTs.

  17. Improved field emission performance of carbon nanotube by introducing copper metallic particles.

    Science.gov (United States)

    Chen, Yiren; Jiang, Hong; Li, Dabing; Song, Hang; Li, Zhiming; Sun, Xiaojuan; Miao, Guoqing; Zhao, Haifeng

    2011-10-03

    To improve the field emission performance of carbon nanotubes (CNTs), a simple and low-cost method was adopted in this article. We introduced copper particles for decorating the CNTs so as to form copper particle-CNT composites. The composites were fabricated by electrophoretic deposition technique which produced copper metallic particles localized on the outer wall of CNTs and deposited them onto indium tin oxide (ITO) electrode. The results showed that the conductivity increased from 10-5 to 4 × 10-5 S while the turn-on field was reduced from 3.4 to 2.2 V/μm. Moreover, the field emission current tended to be undiminished after continuous emission for 24 h. The reasons were summarized that introducing copper metallic particles to decorate CNTs could increase the surface roughness of the CNTs which was beneficial to field emission, restrain field emission current from saturating when the applied electric field was above the critical field. In addition, it could also improve the electrical contact by increasing the contact area between CNT and ITO electrode that was beneficial to the electron transport and avoided instable electron emission caused by thermal injury of CNTs.

  18. Interfacial thermal resistance and thermal rectification in carbon nanotube film-copper systems.

    Science.gov (United States)

    Duan, Zheng; Liu, Danyang; Zhang, Guang; Li, Qingwei; Liu, Changhong; Fan, Shoushan

    2017-03-02

    Thermal rectification occurring at interfaces is an important research area, which contains deep fundamental physics and has extensive application prospects. In general, the measurement of interfacial thermal rectification is based on measuring interfacial thermal resistance (ITR). However, ITRs measured via conventional methods cannot avoid extra thermal resistance asymmetry due to the contact between the sample and the thermometer. In this study, we employed a non-contact infrared thermal imager to monitor the temperature of super-aligned carbon nanotube (CNT) films and obtain the ITRs between the CNT films and copper. The ITRs along the CNT-copper direction and the reverse direction are in the ranges of 2.2-3.6 cm(2) K W(-1) and 9.6-11.9 cm(2) K W(-1), respectively. The obvious difference in the ITRs of the two directions shows a significant thermal rectification effect, and the rectifying coefficient ranges between 0.57 and 0.68. The remarkable rectification factor is extremely promising for the manufacture of thermal transistors with a copper/CNT/copper structure and further thermal logic devices. Moreover, our method could be extended to other 2-dimensional materials, such as graphene and MoS2, for further explorations.

  19. Orientation of Carbon Fibers in Copper matrix Produced by Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Irfan Shirazi M.

    2014-07-01

    Full Text Available Fiber orientation is a big challenge in short fiber reinforced composites. Powder injection molding (PIM process has some intrinsic fiber alignment associated with it. During PIM process fibers in skin region of moldings are aligned as these regions experience higher shear flow caused by the mold walls. Fibers in the core region remain randomly aligned as these regions are far from mold walls and experience lesser shear flow. In this study short carbon fiber (CF reinforced copper matrix composite was developed by PIM process. Two copper composite feedstock formulations were prepared having 5 vol% and 10 vol% CFs and a wax based binder system. Fiber orientation was controlled during injection molding by using a modified mold that has a diverging sprue. The sprue creates converging flow when feedstock enters into the mold cavity. Fiber orientation was analysed after molding using FESEM. The orientation of fibers can be controlled by controlling flow of feedstock into the mold.

  20. The influence of molybdenum on stress corrosion in Ultra Low Carbon Steels with copper addition

    Directory of Open Access Journals (Sweden)

    M. Mazur

    2010-07-01

    Full Text Available The influence of molybdenum content on the process of stress corrosion of ultra-low carbon structural steels with the addition of copper HSLA (High Strength Low Alloy was analyzed. The study was conducted for steels after heat treatment consisting of quenching andfollowing tempering at 600°C and it was obtained microstructure of the tempered martensite laths with copper precipitates and the phaseLaves Fe2Mo type. It was found strong influence of Laves phase precipitate on the grain boundaries of retained austenite on rate anddevelopment of stress corrosion processes. The lowest corrosion resistance was obtained for W3 steel characterized by high contents ofmolybdenum (2.94% Mo which should be connected with the intensity precipitate processes of Fe2Mo phase. For steels W1 and W2which contents molybdenum equals 1.02% and 1.88%, respectively were obtained similar courses of corrosive cracking.

  1. Amperometric sensing of hydrogen peroxide using glassy carbon electrode modified with copper nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sophia, J.; Muralidharan, G., E-mail: muraligru@gmail.com

    2015-10-15

    In this paper, fabrication of glassy carbon electrode (GCE) modified with nano copper particles is discussed. The modified electrode has been tested for the non-enzymatic electrochemical detection of hydrogen peroxide (H{sub 2}O{sub 2}). The copper nanoparticles (Cu NPs) were prepared employing a simple chemical reduction method. The presence of Cu NPs was confirmed through UV–visible (UV–vis) absorption spectroscopy and X-ray diffraction (XRD) analysis. The size and morphology of the particles were investigated using transmission electron microscopy (TEM). The electrochemical properties of the fabricated sensor were studied via cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The electrochemical sensor displayed excellent performance features towards H{sub 2}O{sub 2} detection exhibiting wide linear range, low detection limit, swift response time, good reproducibility and stability.

  2. Carbon nitride supported copper nanoparticles: light-induced electronic effect of the support for triazole synthesis

    Science.gov (United States)

    Nandi, Debkumar; Taher, Abu; Ul Islam, Rafique; Siwal, Samarjeet; Choudhary, Meenakshi; Mallick, Kaushik

    2016-11-01

    The composite framework of graphitic carbon nitride (gCN) supported copper nanoparticle can act as a high-performance photoreactor for the synthesis of 1,2,3-triazole derivatives under light irradiation in the absence of alkaline condition. The photoactivity of gCN originates from an electron transition from the valence band to the conduction band, in the presence of photon energy, and the hot electron acts as a scavenger of the terminal proton of the alkyne molecule to facilitate the formation of copper acetanilide complex. In this study, we have performed the experiment under a different photonic environment, including dark condition, and in the presence and absence of base. A comparative study was also executed using Cu-TiO2 system, as a reference material, in the support of our proposed mechanism. The recycling performance and the photocorrosion effect of the catalyst have also been reported in this study.

  3. ADSORPTION OF COPPER FROM AQUEOUS SOLUTION BY ELAIS GUINEENSIS KERNEL ACTIVATED CARBON

    Directory of Open Access Journals (Sweden)

    NAJUA DELAILA TUMIN

    2008-08-01

    Full Text Available In this study, a series of batch laboratory experiments were conducted in order to investigate the feasibility of Elais Guineensis kernel or known as palm kernel shell (PKS-based activated carbon for the removal of copper from aqueous solution by the adsorption process. Investigation was carried out by studying the influence of initial solution pH, adsorbent dosage and initial concentration of copper. The particle size of PKS used was categorized as PKS–M. All batch experiments were carried out at a constant temperature of 30°C (±2°C using mechanical shaker that operated at 100 rpm. The single component equilibrium data was analyzed using Langmuir, Freundlich, Redlich-Peterson, Temkin and Toth adsorption isotherms.

  4. Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR

    Science.gov (United States)

    Lluveras, A.; Boularand, S.; Andreotti, A.; Vendrell-Saz, M.

    2010-05-01

    This article illustrates the analysis by synchrotron micro-analytical techniques of an azurite painting presenting greenish chromatic degradation. The challenge of the experiments was to obtain the spatial distribution of the degradation products of azurite. Copper hydroxychlorides, carbonates and copper oxalates have been mapped by SR FTIR imaging of cross sections in transmission mode. To complement the information, Py/GC/MS and GC/MS techniques were applied in order to characterize the binding media and organic materials present as well as their degradation products. Results contribute to a better understanding of the decay of blue areas in ancient paintings not only from the particular point of view of azurite weathering, but also by adding information regarding the oxalates’ formation and their distribution in painting samples. Synchrotron radiation demonstrates its capability for the mapping in painting cross sections.

  5. Electroless Plating of Carbon Nanotubes with Copper%碳纳米管的化学镀铜

    Institute of Scientific and Technical Information of China (English)

    凤仪; 袁海龙

    2004-01-01

    A simple chemical method was employed to coat carbon nanotubes with a layer of copper. Due to the hydrophobic nature, large surface curvature, small diameter and large aspect ratio, it is difficult to gain continuous electroless plating layer on the surface of carbon nanotubes. In this paper, a series methods (oxidization, sensitization and activation) are used to add active sites before electroless plating, and the adjustment of the traditional composition of copper electroless plating bath and operating condition can decelerate electroless plating rate. The samples before and after coating were analyzed using transmission electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that the surface of carbon nanotubes was successfully coated with continuous layer of copper, which lays a good foundation for applying carbon nanotubes in composites.

  6. Direct Deposition of Bamboo-Like Carbon Nanotubes on Copper Substrates by Sulfur-Assisted HFCVD

    Directory of Open Access Journals (Sweden)

    Sri Lakshmi Katar

    2008-01-01

    Full Text Available Films of bamboo-like carbon nanotubes (BCNTs were grown directly on copper substrates by sulfur-assisted hot filament chemical vapor deposition (HFCVD. The effects of substrate temperature and growth time over the BCNT structure were investigated. The films were characterized by scanning electron microscopy (SEM, Raman spectroscopy (RS, transmission electron microscopy (TEM, X-ray photoelectron spectroscopy (XPS, and electron field emission (EFE studies. SEM and Raman characterization indicate a transition from the growth of microcrystalline diamond to the growth of a dense entangled network of carbon nanotubes or fibers as the substrate temperature is increased from 400 to 900°C that is accounted for by the base growth model. TEM images show that the nanotubes have regular arrays of nanocavities. These BCNTs show good electron field emission properties as other carbon films.

  7. Combustion Methods for Measuring Low Levels of Carbon in Nickel, Copper, Silver, and Gold

    Science.gov (United States)

    Jacobson, Nathan S.; Savadkouei, Kayvon; Morin, Christophe; Fenstad, Jo; Copland, Evan H.

    2016-12-01

    Laboratory studies and a literature search indicate that there is no definitive procedure for combustion analysis of low levels of carbon in Cu, Ag, and Au. Literature data disagree by one to two orders of magnitude for solubility of carbon in Cu, near the melting point. Data for Ag and Au are very limited. This study develops a procedure for combustion analysis of ppm levels of carbon in high-purity Ni, Cu, Ag, and Au samples. For comparison, each sample is measured with glow discharge mass spectrometry. The study begins with Ni, as the procedure for this material is fairly well established. For the other metals, an optimum accelerator and sample-to-accelerate weight ratio is developed. Fine particle copper is a suitable accelerator for Cu and Ag samples, and also shows potential for Au samples

  8. Evaluation of a reconfigurable portable instrument for copper determination based on luminescent carbon dots.

    Science.gov (United States)

    Salinas-Castillo, Alfonso; Morales, Diego P; Lapresta-Fernández, Alejandro; Ariza-Avidad, María; Castillo, Encarnación; Martínez-Olmos, Antonio; Palma, Alberto J; Capitan-Vallvey, Luis Fermin

    2016-04-01

    A portable reconfigurable platform for copper (Cu(II)) determination based on luminescent carbon dot (Cdots) quenching is described. The electronic setup consists of a light-emitting diode (LED) as the carbon dot optical exciter and a photodiode as a light-to-current converter integrated in the same instrument. Moreover, the overall analog conditioning is simply performed with one integrated solution, a field-programmable analog array (FPAA), which makes it possible to reconfigure the filter and gain stages in real time. This feature provides adaptability to use the platform as an analytical probe for carbon dots coming from different batches with some variations in luminescence characteristics. The calibration functions obtained that fit a modified Stern-Volmer equation were obtained using luminescence signals from Cdots quenching by Cu(II). The analytical applicability of the reconfigurable portable instrument for Cu(II) using Cdots has been successfully demonstrated in tap water analysis.

  9. Removing Copper from Contaminated Water Using Activated Carbon Sorbent by Continuous Flow

    Directory of Open Access Journals (Sweden)

    M.H. Salmani

    2012-07-01

    Full Text Available Introduction: A major concern of human being is accumulation and toxicity of heavy metals in their body. Copper is a heavy metal ion that in concentration of 2 mg/l can cause numerous complications. Different treatment methods have been proposed for removing metals from contaminated water by researchers. Among these methods, sorption seems a better method with high removal efficiency. In this study, conditions for removal of copper ions by activated carbon sorbent were studied with continuous flow. Materials & Methods: This was a laboratory – experimental study. A 20mg/l solution of copper ions was prepared and passed through a 5 × 10 cm column with average output rate of 1.85 ml/min. Output of column was sampled every 30 minutes and the remaining amount of copper ion in each sample was measured by flame atomic absorption. Results: The empty bed volume (EBV was equal to 138 ml. The highest removal efficiency was 99.7 percent at 127 minutes. From equilibrium time, the removal efficiency was constant with time. The adsorption capacity of activated carbon was 0.25mg.g-1. The isotherm study indicated that the sorption data can be obeyed by both Langmuir and Freundlich isotherms (R2>0.95 but Langmuir model had higher agreement with this experimental data (R2= 0.988. Conclusion: The binding of ions to the sorbent in the adsorption process is extremely important. For this column 62.5 minutes after filling was appropriate, so the highest removal efficiency was obtained. Equilibrium time was dependent on the speed of influent through the column in the continuous flow. For selected column, the rate of 1.85 ml/min is a good performance.

  10. Fast voltammetry of metals at carbon-fiber microelectrodes: copper adsorption onto activated carbon aids rapid electrochemical analysis.

    Science.gov (United States)

    Pathirathna, Pavithra; Samaranayake, Srimal; Atcherley, Christopher W; Parent, Kate L; Heien, Michael L; McElmurry, Shawn P; Hashemi, Parastoo

    2014-09-21

    Rapid, in situ trace metal analysis is essential for understanding many biological and environmental processes. For example, trace metals are thought to act as chemical messengers in the brain. In the environment, some of the most damaging pollution occurs when metals are rapidly mobilized and transported during hydrologic events (storms). Electrochemistry is attractive for in situ analysis, primarily because electrodes are compact, cheap and portable. Electrochemical techniques, however, do not traditionally report trace metals in real-time. In this work, we investigated the fundamental mechanisms of a novel method, based on fast-scan cyclic voltammetry (FSCV), that reports trace metals with sub-second temporal resolution at carbon-fiber microelectrodes (CFMs). Electrochemical methods and geochemical models were employed to find that activated CFMs rapidly adsorb copper, a phenomenon that greatly advances the temporal capabilities of electrochemistry. We established the thermodynamics of surface copper adsorption and the electrochemical nature of copper deposition onto CFMs and hence identified a unique adsorption-controlled electrochemical mechanism for ultra-fast trace metal analysis. This knowledge can be exploited in the future to increase the sensitivity and selectivity of CFMs for fast voltammetry of trace metals in a variety of biological and environmental models.

  11. Carbon-coated copper nanoparticles prepared by detonation method and their thermocatalysis on ammonium perchlorate

    Directory of Open Access Journals (Sweden)

    Chongwei An

    2017-03-01

    Full Text Available Carbon-coated copper nanoparticles (CCNPs were prepared by initiating a high-density charge pressed with a mixture of microcrystalline wax, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX, and copper nitrate hydrate (Cu(NO32·3H2O in an explosion vessel filled with nitrogen gas. The detonation products were characterized by transmission electron microcopy (TEM, high resolution transmission electron microcopy (HRTEM, energy dispersive X-ray spectroscopy (EDX, X-ray diffraction (XRD, and Raman spectroscopy. The effects of CCNPs on thermal decomposition of ammonium perchlorate (AP were also investigated by differential scanning calorimeter (DSC. Results indicated that the detonation products were spherical, 25-40 nm in size, and had an apparent core-shell structure. In this structure, the carbon shell was 3-5 nm thick and mainly composed of graphite, C8 (a kind of carbyne, and amorphous carbon. When 5 wt.% CCNPs was mixed with 95 wt.% AP, the high-temperature decomposition peak of AP decreased by 95.97, 96.99, and 96.69 °Cat heating rates of 5, 10, and 20 °C/min, respectively. Moreover, CCNPs decreased the activation energy of AP as calculated through Kissinger’s method by 25%, which indicated outstanding catalysis for the thermal decomposition of AP.

  12. Tribological Properties of PVD Carbon-Copper Composite Films Reinforced by Titanium

    Directory of Open Access Journals (Sweden)

    Lungevics J.

    2016-02-01

    Full Text Available Carbon-copper composite coatings reinforced with titanium were deposited using high power magnetron sputtering technique. Tribological and metrological tests were performed using Taylor Hobson Talysurf Intra 50 measuring equipment and CSM Instruments ball-on-disk type tribometer. Friction coefficient and wear rate were determined at 2N, 4N, 6N loads. It was revealed that friction coefficient decreased at a higher Ti concentration, which was particularly expressed at bigger applied loads. However, wear volume values tended to increase in the beginning, till Ti concentration reached about 11 %, but then decreased, thus providing better nanocoating wear resistance.

  13. Effect of copper ions on voltammetric signals of aminopurines at a carbon electrode

    Directory of Open Access Journals (Sweden)

    Frantisek Jelen

    2010-12-01

    Full Text Available Electrochemical oxidations of aminopurines (adenine–Ade, 2–aminopurine, 2AP, 2,6–diaminopurine, 2,6–DAP and theircomplexes with Cu(I on carbon electrodes (pencil–PeGE wereinvestigated by means of linear sweep voltammetry (LSV andelimination voltammetry with linear scan (EVLS. We found thatthe Cu(I–purine complex was formed not only by aminopurines butalso by purine. On the other hand the complex is not formed in thecase of imidazol or cytosine. The results showed that carbonelectrodes in connection with EVLS can be an excellent prototypefor cheap and fast working sensor for aminopurines in the presenceof copper.

  14. Aspects regarding the tribological evaluation of sintered composites obtained from mixture of copper with carbon fibers

    Science.gov (United States)

    Caliman, R.

    2015-11-01

    This paper presents a study of the tribological properties of sintered composite materials made from combination of copper with short carbon fibers. Sintered composite materials are more effective if refer to specific properties per unit volume compared to conventional isotropic materials. Potential advantages of copper - carbon composite materials are: high resistance to breakage and high value ratios strength/density; resistance to high temperatures; low density and high resistance to wear; low or high friction coefficient. The sintered composite materials used in this research work are obtained combining different percentages of copper with short carbon fibres with iron and lead in order to investigate the variation of the friction behaviour. Varying the percentage of copper from 92,2% to 97,6% and the percentage of short carbon fibres from 7,8% to 2,4%, five different composite materials are obtained and tested. Friction tests are carried out, at room temperature, in dry conditions, on a pin-on-disc machine. The friction coefficient was measured using abrasive discs made from steel 4340 having the average hardness of 40 HRC, and sliding velocity of 0,6 m/sec. The main objective of this research work it was to identify a combination of materials with improved friction behaviour. The experimental results revealed that the force applied on the specimen during the tests, is playing a very important role regarding friction coefficient and also the wearing speed. Graphite particles are conveyed consistently inside the net, enhancing scraped spot safety and voltage drop over normal composite material. The static tests demonstrated that this new kind of sintered composite material has preferable electrical execution over previous brush material in the same conditions, and the element tests demonstrated that the temperature climb is not enormous when the brush with this new composite material is exchanged on with huge current and the surface scraped spot is littler amid

  15. RTA-treated carbon fiber/copper core/shell hybrid for thermally conductive composites.

    Science.gov (United States)

    Yu, Seunggun; Park, Bo-In; Park, Cheolmin; Hong, Soon Man; Han, Tae Hee; Koo, Chong Min

    2014-05-28

    In this paper, we demonstrate a facile route to produce epoxy/carbon fiber composites providing continuous heat conduction pathway of Cu with a high degree of crystal perfection via electroplating, followed by rapid thermal annealing (RTA) treatment and compression molding. Copper shells on carbon fibers were coated through electroplating method and post-treated via RTA technique to reduce the degree of imperfection in the Cu crystal. The epoxy/Cu-plated carbon fiber composites with Cu shell of 12.0 vol % prepared via simple compression molding, revealed 18 times larger thermal conductivity (47.2 W m(-1) K(-1)) in parallel direction and 6 times larger thermal conductivity (3.9 W m(-1) K(-1)) in perpendicular direction than epoxy/carbon fiber composite. Our novel composites with RTA-treated carbon fiber/Cu core/shell hybrid showed heat conduction behavior of an excellent polymeric composite thermal conductor with continuous heat conduction pathway, comparable to theoretical values obtained from Hatta and Taya model.

  16. COPPER/CARBON CORE SHELL NANOPARTICLES AS ADDITIVE FOR NATURAL FIBER/WOOD PLASTIC BLENDS

    Directory of Open Access Journals (Sweden)

    Qinglin Wu,

    2012-06-01

    Full Text Available Copper/carbon core/shell nanoparticles (CCCSNs recently have been introduced as an industrial material. In this paper, composites based on high density polyethylene (HDPE, bamboo fiber, CCCSNs, and coupling agent (MAPE were prepared by melt compounding. The influence of CCCSN content on the resulting composites’ mechanical, biological resistance, and thermal properties was investigated. It was found that CCCSNs within the carbon black matrix were processed well with bamboo fiber-plastic blends through mixing and injection molding. The materials enhanced composite strength and modulus-related properties. Composites with CCCSNs and natural fibers reduced heat capacity and thermal diffusivity. Composites with CCCSN materials also enhanced termite and mold performance. Thus, the material can be used as additive for plastics and other polymers to modify strength properties, biological resistance (e.g., mold and stain, and thermal conductivity properties.

  17. Voltammetric copper(II) determination with a montmorillonite-modified carbon paste electrode

    Energy Technology Data Exchange (ETDEWEB)

    Kula, P. [Institute of Geonics, Academy of Sciences of Czech Republic, Studertska 1768, 708 00 Ostrava (Czech Republic); Navratilova, Z. [Institute of Geonics, Academy of Sciences of Czech Republic, Studertska 1768, 708 00 Ostrava (Czech Republic)

    1996-03-01

    The clay mineral montmorillonite has been tested as modifier for the carbon paste electrode with a novel electrode modification technique. The differential pulse voltammetric determination of copper(II) by means of this modified carbon paste electrode has been studied. A detection limit of 4 x 10{sup -8} mol/l has been achieved after 10 min preconcentration under open circuit conditions with subsequent anodic stripping voltammetry. The calibration curve for Cu(II) is linear in the range of 4 x 10{sup -8}-8 x 10{sup -7} mol/l. Pb interferes in a 10-fold molar and Cd and Hg in a 100-fold molar excess. The interference by humic ligands is significant. (orig.). With 5 figs., 1 tab.

  18. Characterization and nanomechanical properties of novel dental implant coatings containing copper decorated-carbon nanotubes.

    Science.gov (United States)

    Sasani, N; Vahdati Khaki, J; Mojtaba Zebarjad, S

    2014-09-01

    Fluorapatite-titania coated Ti-based implants are promising for using in dental surgery for restoring teeth. One of the challenges in implantology is to achieve a bioactive coating with appropriate mechanical properties. In this research, simple sol-gel method was developed for synthesis of fluorapatite-titania-carbon nanotube decorated with antibacterial agent. Triethyl phosphate [PO4(C2H5)3], calcium nitrate [Ca(NO3)2] and ammonium fluoride (NH4F) were used as precursors under an ethanol-water based solution for fluorapatite (FA) production. Titanium isopropoxide and isopropanol were used as starting materials for making TiO2 sol-gels. Also, Copper acetate [Cu(C2H3O2)2·H2O] was used as precursor for decoration of multi walled carbon nanotubes (MWCNTs) with wet chemical method. The decorated MWCNTs (CNT(Cu)) were evaluated by transmission electron microscopy (TEM). The phase identification of the FA-TiO2-CNT(Cu) coating was carried out by XRD analysis. Morphology of coated samples was investigated by SEM observations. The surface elastic modulus and hardness of coatings were studied using nanoindentation technique. The results indicate that novel dental implant coating containing FA, TiO2 and copper decorated MWCNTs have proper morphological features. The results of nanoindentation test show that incorporation of CNT(Cu) in FA-TiO2 matrix can improve the nanomechanical properties of composite coating.

  19. Standard Specification for Low-Carbon Nickel-Chromium-Molybdenum, Low-Carbon Nickel-Chromium-Molybdenum-Copper, Low-Carbon Nickel-Chromium-Molybdenum-Tantalum, Low-Carbon Nickel-Chromium-Molybdenum-Tungsten, and Low-Carbon Nickel-Molybdenum-Chromium Alloy Plate, Sheet, and Strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2015-01-01

    Standard Specification for Low-Carbon Nickel-Chromium-Molybdenum, Low-Carbon Nickel-Chromium-Molybdenum-Copper, Low-Carbon Nickel-Chromium-Molybdenum-Tantalum, Low-Carbon Nickel-Chromium-Molybdenum-Tungsten, and Low-Carbon Nickel-Molybdenum-Chromium Alloy Plate, Sheet, and Strip

  20. Standard Specification for Low-Carbon Nickel-Chromium-Molybdenum, Low-Carbon Nickel-Molybdenum-Chromium, Low-Carbon Nickel-Molybdenum-Chromium-Tantalum, Low-Carbon Nickel-Chromium-Molybdenum-Copper, and Low-Carbon Nickel-Chromium-Molybdenum-Tungsten Alloy Rod

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2015-01-01

    Standard Specification for Low-Carbon Nickel-Chromium-Molybdenum, Low-Carbon Nickel-Molybdenum-Chromium, Low-Carbon Nickel-Molybdenum-Chromium-Tantalum, Low-Carbon Nickel-Chromium-Molybdenum-Copper, and Low-Carbon Nickel-Chromium-Molybdenum-Tungsten Alloy Rod

  1. Water treatment with exceptional virus inactivation using activated carbon modified with silver (Ag) and copper oxide (CuO) nanoparticles.

    Science.gov (United States)

    Shimabuku, Quelen Letícia; Arakawa, Flávia Sayuri; Fernandes Silva, Marcela; Ferri Coldebella, Priscila; Ueda-Nakamura, Tânia; Fagundes-Klen, Márcia Regina; Bergamasco, Rosangela

    2017-08-01

    Continuous flow experiments (450 mL min(-1)) were performed in household filter in order to investigate the removal and/or inactivation of T4 bacteriophage, using granular activated carbon (GAC) modified with silver and/or copper oxide nanoparticles at different concentrations. GAC and modified GAC were characterized by X-ray diffractometry, specific surface area, pore size and volume, pore average diameter, scanning electron microscopy, transmission electron microscopy, zeta potential and atomic absorption spectroscopy. The antiviral activity of the produced porous media was evaluated by passing suspensions of T4 bacteriophage (∼10(5) UFP/mL) through filters. The filtered water was analyzed for the presence of the bacteriophage and the release of silver and copper oxide. The porous media containing silver and copper oxide nanoparticles showed high inactivation capacity, even reaching reductions higher than 3 log. GAC6 (GAC/Ag0.5%Cu1.0%) was effective in the bacteriophage inactivation, reaching 5.53 log reduction. The levels of silver and copper released in filtered water were below the recommended limits (100 ppb for silver and 1000 ppb for copper) in drinking water. From this study, it is possible to conclude that activated carbon modified with silver and copper oxide nanoparticles can be used as a filter for virus removal in the treatment of drinking water.

  2. Removal of Copper (II Ions from Aqueous Solutions by Adsorption with Low Cost Acid Activated Cynodon Dactylon Carbon

    Directory of Open Access Journals (Sweden)

    U. Gayathri

    2011-01-01

    Full Text Available The main purpose of this work was to exploit low cost and efficient sorbents for the removal of copper from aqueous solution using Cynodon dactylon carbon. It was observed from the experimental results that almost 90-100% copper can be removed from the aqueous solution. Adsorption kinetics and equilibrium have been investigated as a function of initial copper ion concentration. pH, contact time and adsorbent dosage. Kinetics studies suggested that the adsorption allowed first order reaction. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models. On the basis of experimental results and the model parameters, it can be concluded that the carbonaceous Cynodon dactylon is effective for the removal of copper ion from aqueous solution.

  3. Cobalt/copper-decorated carbon nanofibers as novel non-precious electrocatalyst for methanol electrooxidation

    Science.gov (United States)

    Barakat, Nasser A. M.; El-Newehy, Mohamed; Al-Deyab, Salem S.; Kim, Hak Yong

    2014-01-01

    In this study, Co/Cu-decorated carbon nanofibers are introduced as novel electrocatalyst for methanol oxidation. The introduced nanofibers have been prepared based on graphitization of poly(vinyl alcohol) which has high carbon content compared to many polymer precursors for carbon nanofiber synthesis. Typically, calcination in argon atmosphere of electrospun nanofibers composed of cobalt acetate tetrahydrate, copper acetate monohydrate, and poly(vinyl alcohol) leads to form carbon nanofibers decorated by CoCu nanoparticles. The graphitization of the poly(vinyl alcohol) has been enhanced due to presence of cobalt which acts as effective catalyst. The physicochemical characterization affirmed that the metallic nanoparticles are sheathed by thin crystalline graphite layer. Investigation of the electrocatalytic activity of the introduced nanofibers toward methanol oxidation indicates good performance, as the corresponding onset potential was small compared to many reported materials; 310 mV (vs. Ag/AgCl electrode) and a current density of 12 mA/cm2 was obtained. Moreover, due to the graphite shield, good stability was observed. Overall, the introduced study opens new avenue for cheap and stable transition metals-based nanostructures as non-precious catalysts for fuel cell applications.

  4. Laccase Biosensor Based on Electrospun Copper/Carbon Composite Nanofibers for Catechol Detection

    Directory of Open Access Journals (Sweden)

    Jiapeng Fu

    2014-02-01

    Full Text Available The study compared the biosensing properties of laccase biosensors based on carbon nanofibers (CNFs and copper/carbon composite nanofibers (Cu/CNFs. The two kinds of nanofibers were prepared by electrospinning and carbonization under the same conditions. Scanning electron microscopy (SEM, X-ray diffraction (XRD and Raman spectroscopy were employed to investigate the morphologies and structures of CNFs and Cu/CNFs. The amperometric results indicated that the Cu/CNFs/laccase(Lac/Nafion/glass carbon electrode (GCE possessed reliable analytical performance for the detection of catechol. The sensitivity of the Cu/CNFs/Lac/Nafion/GCE reached 33.1 μA/mM, larger than that of CNFs/Lac/Nafion/GCE. Meanwhile, Cu/CNFs/Lac/Nafion/GCE had a wider linear range from 9.95 × 10−6 to 9.76 × 10−3 M and a lower detection limit of 1.18 μM than CNFs/Lac/Nafion/GCE. Moreover, it exhibited a good repeatability, reproducibility, selectivity and long-term stability, revealing that electrospun Cu/CNFs have great potential in biosensing.

  5. Laccase Biosensor Based on Electrospun Copper/Carbon Composite Nanofibers for Catechol Detection

    Science.gov (United States)

    Fu, Jiapeng; Qiao, Hui; Li, Dawei; Luo, Lei; Chen, Ke; Wei, Qufu

    2014-01-01

    The study compared the biosensing properties of laccase biosensors based on carbon nanofibers (CNFs) and copper/carbon composite nanofibers (Cu/CNFs). The two kinds of nanofibers were prepared by electrospinning and carbonization under the same conditions. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy were employed to investigate the morphologies and structures of CNFs and Cu/CNFs. The amperometric results indicated that the Cu/CNFs/laccase(Lac)/Nafion/glass carbon electrode (GCE) possessed reliable analytical performance for the detection of catechol. The sensitivity of the Cu/CNFs/Lac/Nafion/GCE reached 33.1 μA/mM, larger than that of CNFs/Lac/Nafion/GCE. Meanwhile, Cu/CNFs/Lac/Nafion/GCE had a wider linear range from 9.95 × 10−6 to 9.76 × 10−3 M and a lower detection limit of 1.18 μM than CNFs/Lac/Nafion/GCE. Moreover, it exhibited a good repeatability, reproducibility, selectivity and long-term stability, revealing that electrospun Cu/CNFs have great potential in biosensing. PMID:24561403

  6. Investigation of Structure and Physico-Mechanical Properties of Composite Materials Based on Copper - Carbon Nanoparticles Powder Systems

    Directory of Open Access Journals (Sweden)

    Kovtun V.

    2015-04-01

    Full Text Available Physico-mechanical and structural properties of electrocontact sintered copper matrix- carbon nanoparticles composite powder materials are presented. Scanning electron microscopy revealed the influence of preliminary mechanical activation of the powder system on distribution of carbon nanoparticles in the metal matrix. Mechanical activation ensures mechanical bonding of nanoparticles to the surface of metal particles, thus giving a possibility for manufacture of a composite with high physico-mechanical properties.

  7. Effect of Acid and Alcohol Network Forces within Functionalized Multiwall Carbon Nanotubes Bundles on Adsorption of Copper (II) Species

    Science.gov (United States)

    Adsorption of metals on carbon nanotubes (CNTs) has important applications in sensors, membranes, and water treatment. The adsorptive capacity of multiwall CNTs for copper species in water depends on the type of functional group present on their surface. The alcohol (COOH) and ac...

  8. Three-dimensional porous hollow fibre copper electrodes for efficient and high-rate electrochemical carbon dioxide reduction

    NARCIS (Netherlands)

    Kas, Recep; Hummadi, Khalid Khazzal; Kortlever, Ruud; Wit, de Patrick; Milbrat, Alexander; Luiten-Olieman, Mieke W.J.; Benes, Nieck E.; Koper, Marc T.M.; Mul, Guido

    2016-01-01

    Aqueous-phase electrochemical reduction of carbon dioxide requires an active, earth-abundant electrocatalyst, as well as highly efficient mass transport. Here we report the design of a porous hollow fibre copper electrode with a compact three-dimensional geometry, which provides a large area, three-

  9. Design and evaluation of carbon fibre-reinforced launch packages with segmented, copper and molybdenum fibre armatures

    NARCIS (Netherlands)

    Koops, M.; Huijser, T.; Karthaus, W.

    1997-01-01

    Fibre armatures have been studied both dynamically and statically to gain insight in their electrothermal and mechanical behaviour. In the first part of this paper, the results of launch experiments with single and multi-segment copper and molybdenum fibre armatures integrated in carbon-fibre reinfo

  10. Nano-engineered Multiwall Carbon Nanotube-copper Composite Thermal Interface Material for Efficient Heat Conduction

    Science.gov (United States)

    Ngo, Quoc; Cruden, Brett A.; Cassell, Alan M.; Sims, Gerard; Li, Jun; Meyyappa, M.; Yang, Cary Y.

    2005-01-01

    Efforts in integrated circuit (IC) packaging technologies have recently been focused on management of increasing heat density associated with high frequency and high density circuit designs. While current flip-chip package designs can accommodate relatively high amounts of heat density, new materials need to be developed to manage thermal effects of next-generation integrated circuits. Multiwall carbon nanotubes (MWNT) have been shown to significantly enhance thermal conduction in the axial direction and thus can be considered to be a candidate for future thermal interface materials by facilitating efficient thermal transport. This work focuses on fabrication and characterization of a robust MWNT-copper composite material as an element in IC package designs. We show that using vertically aligned MWNT arrays reduces interfacial thermal resistance by increasing conduction surface area, and furthermore, the embedded copper acts as a lateral heat spreader to efficiently disperse heat, a necessary function for packaging materials. In addition, we demonstrate reusability of the material, and the absence of residue on the contacting material, both novel features of the MWNT-copper composite that are not found in most state-of-the-art thermal interface materials. Electrochemical methods such as metal deposition and etch are discussed for the creation of the MWNT-Cu composite, detailing issues and observations with using such methods. We show that precise engineering of the composite surface affects the ability of this material to act as an efficient thermal interface material. A thermal contact resistance measurement has been designed to obtain a value of thermal contact resistance for a variety of different thermal contact materials.

  11. Removal of copper, nickel and chromium mixtures from metal plating wastewater by adsorption with modified carbon foam.

    Science.gov (United States)

    Lee, Chang-Gu; Lee, Soonjae; Park, Jeong-Ann; Park, Chanhyuk; Lee, Sang Jeong; Kim, Song-Bae; An, Byungryul; Yun, Seong-Taek; Lee, Sang-Hyup; Choi, Jae-Woo

    2017-01-01

    In this study, the characterizations and adsorption efficiencies for chromium, copper and nickel were evaluated using manufacture-grade Fe2O3-carbon foam. SEM, XRD, XRF and BET analyses were performed to determine the characteristics of the material. Various pore sizes (12-420 μm) and iron contents (3.62%) were found on the surface of the Fe2O3-carbon foam. Fe2O3-carbon foam was found to have excellent adsorption efficiency compared to carbon foam for mixed solutions of cationic and anionic heavy metals. The adsorption capacities for chromium, copper and nickel were 6.7, 3.8 and 6.4 mg/g, respectively, which were obtained using a dual exponential adsorption model. In experiments with varying dosages of the Fe2O3 powder, no notable differences were observed in the removal efficiency. In a fixed-bed column test, Fe2O3-carbon foam achieved adsorption capacities for chromium, copper and nickel of 33.0, 12.0 and 9.5 mg/g, respectively, after 104 h. Based on these results, Fe2O3-carbon foam was observed to be a promising material for treatment of plating wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Towards the comprehension of the role of copper and iron in MSWI fly ash carbon degradation

    Energy Technology Data Exchange (ETDEWEB)

    Grandesso, E.; Arosio, C.; Collina, E.; Lasagni, M.; Pitea, D. [Universita Milano-Bicocca, Milano (Italy); Fermo, P. [Universita degli Studi di Milano, Milano (Italy)

    2004-09-15

    The formation of PolyChlorinated Dibenzo-p-Dioxins (PCDD) and PolyChlorinated DibenzoFurans (PCDF) from many anthropogenic sources has been noticed since the 1970s. In particular, municipal solid waste incinerators (MSWI) are a source of PCDD/F and their formation has been proposed to occur by various homogeneous and heterogeneous mechanisms. In the low temperature range (200-600 C) two mechanisms generally are accepted: (i) heterogeneous reactions on the fly ash surface involving gas-phase or adsorbed precursors such as chlorinated phenols, chlorinated benzenes and polychlorinated biphenyls and (ii) the formation, eventually catalysed, from fly ash carbon, chlorine and oxygen. In the latter, usually termed the de novo synthesis, contradictory conclusions are provided about the key parameters and their role. Apart from temperature and reaction time, these parameters include: the amount and structure of carbon in the fly ash; the chlorine speciation together with the relative importance of gas-phase inorganic chlorine with respect to extractable organic chlorine, ash-bound chlorine, inorganic chlorides such as metal chloride or water-soluble earth metal chloride; the oxygen percentage in the reaction atmosphere. As for the metal chlorides, copper(II) chloride has proven to be very active in promoting PCDDs/Fs formation even if less efficiently, iron(III) chlorides participates in or promotes formation via de novo synthesis. In a previous paper we reported the CO{sub 2} evolution curves from MSWI fly ash and model systems studied by means of the TG-FTIR technique. Model systems consisted of physically ground mixtures of active carbon, C, a silica, SiO{sub 2}, matrix, and CuCl{sub 2} or CuO or CuSO{sub 4}. It was shown that the number of peaks in the curves depended on the system studied. Thus it was possible to conclude that low temperature carbon oxidation was highly dependent on the catalyst added to the model mixtures as well as on the metals already present in

  13. Plastic membrane, carbon paste and multiwalled carbon nanotube composite coated copper wire sensors for determination of oxeladin citrate using batch and flow injection techniques

    OpenAIRE

    Zayed,Sayed I. M.; Yousry M Issa

    2013-01-01

    The fabrication and performance characteristics of three novel potentiometric sensors for the determination of oxeladin citrate are described. The proposed sensors include a PVC plastic membrane sensor, a carbon paste sensor and a multiwalled carbon nanotube (MWCNT) composite coated copper wire sensor. The sensors are based on the oxeladin-phosphotungstate ion associate as electroactive material and dibutyl phthalate as solvent mediator. The developed sensors exhibited near nernstian slopes o...

  14. The over-step coalescence of carbon atoms on copper surface in the CVD growth of graphene: density functional calculations

    Directory of Open Access Journals (Sweden)

    Yingfeng Li

    2013-05-01

    Full Text Available The ways in which carbon atoms coalesce over the steps on copper (111 surface are ascertained by density functional theory (DFT calculations in the context of chemical vapor deposition (CVD growth of graphene. Two strategies, (1 by putting carbon atoms on and under the steps separately and (2 by importing additional carbon atoms between the ones separated by the steps, have been attempted to investigate if an over-step coalescence of carbon atoms could take place. Based on analyses about the optimized configurations and adsorption energies of carbon atoms nearby the steps, as well as the energy evolution curve of the system throughout the geometry optimizations process, we determined the main way in which graphene grows over the steps continuously: the carbon atoms, adsorbed additionally on the locations between the already existing ones which are separated by the steps, link them (these carbon atoms separated by the steps together. The direct over-step coalescence of the carbon atoms separated by the steps is very difficult, although the energy barrier preventing their coalescence can be weakened by importing carbon atoms on and under the steps gradually. Our results imply potential applications in directing the fabrication of graphene with particular structure by controlling the surface topography of copper substrate.

  15. Co-sputter deposited nickel-copper bimetallic nanoalloy embedded carbon films for electrocatalytic biomarker detection

    Science.gov (United States)

    Shiba, Shunsuke; Kato, Dai; Kamata, Tomoyuki; Niwa, Osamu

    2016-06-01

    We report the fabrication of a nickel (Ni)-copper (Cu) bimetallic nanoalloy (~3 nm) embedded carbon film electrode with the unbalanced magnetron (UBM) co-sputtering technique, which requires only a one-step process at room temperature. Most of each nanoalloy body was firmly embedded in a chemically stable carbon matrix with an atomically flat surface (Ra: 0.21 nm), suppressing the aggregation and/or detachment of the nanoalloy from the electrode surface. The nanoalloy size and composition can be controlled simply by individually controlling the target powers of carbon, Ni and Cu, which also makes it possible to localize the nanoalloys near the electrode surface. This electrode exhibited excellent electrocatalytic activity for d-mannitol, which should be detected with a low detection limit in urine samples for the diagnosis of severe intestinal diseases. With a Ni/Cu ratio of around 64/36, the electrocatalytic current per metal area was 3.4 times larger than that of an alloy film electrode with a similar composition (~70/30). This improved electrocatalytic activity realized higher stability (n = 60, relative standard deviation (RSD): 4.6%) than the alloy film (RSD: 32.2%) as demonstrated by continuous measurements of d-mannitol.We report the fabrication of a nickel (Ni)-copper (Cu) bimetallic nanoalloy (~3 nm) embedded carbon film electrode with the unbalanced magnetron (UBM) co-sputtering technique, which requires only a one-step process at room temperature. Most of each nanoalloy body was firmly embedded in a chemically stable carbon matrix with an atomically flat surface (Ra: 0.21 nm), suppressing the aggregation and/or detachment of the nanoalloy from the electrode surface. The nanoalloy size and composition can be controlled simply by individually controlling the target powers of carbon, Ni and Cu, which also makes it possible to localize the nanoalloys near the electrode surface. This electrode exhibited excellent electrocatalytic activity for d

  16. Nanosize copper encapsulated carbon thin films on a dye-sensitized solar cell cathode.

    Science.gov (United States)

    Huang, Chien-Hua; Wang, H Paul; Liao, Chang-Yu

    2010-07-01

    Deposition of the nanosize copper encapsulated carbon (Cu@C) thin film onto the cathode has been studied to enhance efficiency of the dye-sensitized solar cell (DSSC). The X-ray diffraction (XRD) patterns of the Cu@C are suggestive of existence of metallic copper (Cu) nanoparticles in the thin film. The UV-visible spectrum of the Cu@C coated on indium-doped tin oxide (ITO) shows a red shift (probably due to the longitudinal resonance) as the size of Cu in the Cu@C increases. Moreover, the images observed by field-emission scanning electron microscopy (FE-SEM) indicate that the Cu@C nanoparticles are well dispersed on ITO. By extended X-ray absorption fine structure (EXAFS) spectroscopy, a decrease of the coordination number (CN) of Cu-Cu with decreasing sizes of Cu in the Cu@C is observed. Interestingly, an enhanced efficiency of the DSSC with the Cu@C nanoparticles coated ITO cathode by 50% is found if compared with the relatively expensive Pt electrode. As the size of Cu in the Cu@C on ITO decreases (e.g., 20 --> 7 nm), the efficiency of the DSSC can be increased by 80% approximately.

  17. Microstructure and mechanical behavior of copper coated multiwall carbon nanotubes reinforced aluminum composites

    Energy Technology Data Exchange (ETDEWEB)

    Jagannatham, M.; Sankaran, S.; Haridoss, Prathap, E-mail: prathap@iitm.ac.in

    2015-06-25

    Electroless copper coatings were performed on purified carbon nanotubes (CNT), with varying deposition time and the optimum deposition time in terms of uniform deposition was determined to be 45 min. Different amounts of optimized Cu coated CNT (CNT (Cu)) and Al powders were ball milled. CNT (Cu) reinforced Al (Al-CNT (Cu)) composites were prepared by spark plasma sintering (SPS). Pure CNT reinforced Al (Al-CNT) composites were also prepared by SPS. The ball milled powders and composites were characterized using X-Ray diffraction, scanning electron microscopy, Raman spectroscopy, and transmission electron microscopy (TEM). Microhardness and compression properties of the composites were measured. TEM images of ball milled powders and composites revealed uniform distribution of CNT in matrix. Mechanical properties of Al-CNT (Cu) composites are superior to Al-CNT composites. The maximum enhancement in compressive strength of Al-CNT (Cu) composites is 154% for 2 wt% reinforcement; this enhancement is attributed to the copper coating on CNT surface.

  18. Non-enzymatic glucose sensor based on electrodeposited copper on carbon paste electrode (Cu/CPE)

    Energy Technology Data Exchange (ETDEWEB)

    Nurani, Dita Arifa, E-mail: d.arifa@sci.ui.ac.id; Wibowo, Rahmat; Fajri, Iqbal Farhan El [Department of Chemistry, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia)

    2016-04-19

    The development of non-enzymatic glucose sensor has much attention due to their applications in glucose monitoring. In this research, copper oxide is used as a non-enzymatic glucose sensor by oxidizing glucose to gluconolactone. Copper was electrodeposited on Carbon paste electrode (CPE) at constant potential. The experimental condition was varied in electrodeposition of Cu with the following parameters: Electrodeposition time 60 s, 120 s and 180 s and potential reduction -0.166 V, -0.266 V and -0.366 V. The effective performance of these working electrodes in sensing glucose was investigated. The Cu/CPE which used -0.366 V potential reduction and 120 s electrodeposition time shows the best performance. The amperometric response current in concentration range 1.6-62.5 mM of glucose gives the good linearity R{sup 2} = 0.9988, low detection limit 0.6728 mM and high sensitivity 1183.59 µA mM{sup −1}cm{sup −2}. Furthermore this sensor exhibited a good repeatability with %RSD = 1.31% (n=10) and high stability with %RSD = 1.51% (n=5 days). The homogeneity of Cu particles on CPE was investigated by Scanning Electron Microscope (SEM).

  19. Adsorption of Thiophenic Compounds from Model Diesel Fuel Using Copper and Nickel Impregnated Activated Carbons

    Directory of Open Access Journals (Sweden)

    Ramin Karimzadeh

    2012-10-01

    Full Text Available Adsorption of sulfur compoundsby porous materials is an effective way to produce cleaner diesel fuel.In this study, adsorption of refractory thiophenic sulfur compounds, i.e., benzothiophene (BT, dibenzothiophene (DBT, and 4,6-dimethyldibenzothiophene (4,6-DMDBT in single-solute systems from n-hexane solutions onto metal-impregnated activated carbons was investigated. A hydrogen-treated activated carbon fiber was selectively loaded with Ni, NiO, Cu, Cu2O, and CuO species to systematically assess the impact of each metal species on the adsorption of thiophenic compounds (TC. Metal-loaded adsorbents had the same total metal contents and similar microporosities, but contained different types of copper or nickel species. All metal-loaded adsorbents showed enhanced adsorption of tested TC. Cu2O- or NiO-loaded adsorbents exhibited the highest uptakes, due to more specific interactions between Cu+ or Ni2+ species and TC molecules. The theoretical monolyer coverage of TC on the exposed Cu+ sites was estimated and compared with that calculated from the experimental data. Results suggested catalytic conversion of TC molecules to other compounds on the Cu+ sites, followed by adsorption of reaction products onto the carbon surface or multilayer accumulation of TC molecules on the Cu+sites. TC adsorption uptake of the majority of adsorbents followed the order of: 4,6-DMDBT > DBT > BT due to higher intensity of specific and non-specific interactions of larger TC molecules with adsorbents.

  20. Erosion and Modifications of Tungsten-Coated Carbon and Copper Under High Heat Flux

    Institute of Scientific and Technical Information of China (English)

    Liu Xiang(刘翔); S.Tamura; K.Tokunaga; N.Yoshida; Zhang Fu(张斧); Xu Zeng-yu(许增裕); Ge Chang-chun(葛昌纯); N.Noda

    2003-01-01

    Tungsten-coated carbon and copper was prepared by vacuum plasma spraying (VPS)and inert gas plasma spraying (IPS), respectively. W/CFC (Tungsten /Carbon Fiber-Enhancedmaterial) coating has a diffusion barrier that consists of W and Re multi-layers pre-deposited byphysical vapor deposition on carbon fiber-enhanced materials, while W/Cu coating has a gradedtransition interface. Different grain growth processes of tungsten coatings under stable and tran-sient heat loads were observed, their experimental results indicated that the recrystallizing tem-perature of VPS-W coating was about 1400 ℃ and a recrystallized columnar layer of about 30μmthickness was formed by cyclic heat loads of 4 ms pulse duration. Erosion and modifications ofW/CFC and W/Cu coatings under high heat load, such as microstructure changes of interface,surface plastic deformations and cracks, were investigated, and the erosion mechanism erosionproducts) of these two kinds of tungsten coatings under high heat flux was also studied.

  1. Kinetic separation of carbon dioxide and methane on a copper metal-organic framework.

    Science.gov (United States)

    Bao, Zongbi; Alnemrat, Sufian; Yu, Liang; Vasiliev, Igor; Ren, Qilong; Lu, Xiuyang; Deng, Shuguang

    2011-05-15

    Separation of carbon dioxide and methane is an important issue in upgrading low-quality natural gas. Adsorption equilibria and kinetics of CO(2) and CH(4) on a copper metal-organic framework (MOF), Cu(hfipbb)(H(2)hfipbb)(0.5) [H(2)hfipbb=4,4'-(hexafluoroisopropylidene) bis(benzoic acid)], were investigated to evaluate the feasibility of removing CO(2) from CH(4) in a pressure swing adsorption process using this new MOF adsorbent. The heat of adsorption of CO(2) on the Cu-MOF at zero-coverage (29.7 kJ/mol) is much lower than those on a carbon molecular sieve and a zeolite 5A adsorbent; and the heat of adsorption of CH(4) on the Cu-MOF (21.4 kJ/mol) is similar to that on the zeolite 5A adsorbent and smaller than that on a carbon molecular sieve. The Cu-MOF being investigated has apertures of (~3.5 × 3.5 Å), which favors the kinetically controlled separation of CO(2) and CH(4). The kinetic selectivity is found to be 26 at 298 K, and the overall selectivity (combining the equilibrium and kinetic effects) is about 25 for an adsorption separation process. These results suggest that the Cu-MOF adsorbent is an attractive alternative adsorbent for the CO(2)/CH(4) separation.

  2. Copper coated carbon fiber reinforced plastics for high and ultra high vacuum applications

    Science.gov (United States)

    Burri, F.; Fertl, M.; Feusi, P.; Henneck, R.; Kirch, K.; Lauss, B.; Rüttimann, P.; Schmidt-Wellenburg, P.; Schnabel, A.; Voigt, J.; Zenner, J.; Zsigmond, G.

    2014-03-01

    We have used copper-coated carbon fiber reinforced plastic (CuCFRP) for the construction of high and ultra-high vacuum recipients. The vacuum performance is found to be comparable to typical stainless steel used for this purpose. In test recipients we have reached pressures of 2E-8 mbar and measured a desorption rate of 1E-11 mbar*liter/s/cm^2; no degradation over time (2 years) has been found. Suitability for baking has been found to depend on the CFRP production process, presumably on the temperature of the autoclave curing. Together with other unique properties of CuCFRP such as low weight and being nearly non-magnetic, this makes it an ideal material for many high-end vacuum applications.

  3. Corrosion Inhibition of the Galvanic Couple Copper-Carbon Steel in Reverse Osmosis Water

    Directory of Open Access Journals (Sweden)

    Irene Carrillo

    2011-01-01

    Full Text Available The purpose of this paper is to evaluate the electrochemical behaviour of corrosion inhibition of the copper-carbon steel galvanic couple (Cu-CS, exposed to reverse osmosis water (RO used for rinsing of heat exchangers for heavy duty machinery, during manufacture. Molybdate and nitrite salts were utilized to evaluate the inhibition behaviour under galvanic couple conditions. Cu-CS couple was used as working electrodes to measure open circuit potential (OCP, potentiodynamic polarization (PP, and electrochemical impedance spectroscopy (EIS. The surface conditions were characterized by scanning electron microscopy (SEM and electron dispersive X-ray spectroscopy (EDS. The most effective concentration ratio between molybdate and nitrite corrosion inhibitors was determined. The morphological study indicated molybdate deposition on the anodic sites of the galvanic couple. The design of molybdate-based corrosion inhibitor developed in the present work should be applied to control galvanic corrosion of the Cu-CS couple during cleaning in the manufacture of heat exchangers.

  4. Characteristics of copper meshes coated with carbon nanotubes via electrophoretic deposition

    Science.gov (United States)

    Kim, Bu-Jong; Park, Jong-Seol; Hwang, Young-Jin; Park, Jin-Seok

    2016-09-01

    This study demonstrates the characteristics of a hybrid-type transparent electrode for touch screen panels, which was fabricated by coating carbon nanotubes (CNTs) via electrophoretic deposition (EPD) on copper (Cu)-meshes. The surface morphologies, visible-range transmittance and reflectance, and chromatic properties, such as yellowness and redness, of the fabricated CNTs-coated Cu mesh electrodes were characterized as functions of their dimensions (line-to-line spacing, line width, and electrode thickness) and compared with those of the Cu-mesh electrodes without coating of CNTs. The experimental results showed that the coating of CNTs substantially reduced the reflectance of the Cu-mesh electrodes and also improved their chromatic properties with their transmittance and sheet resistance only slightly changed, subsequently indicating that the CNTs-coated Cu-mesh electrodes possessed desirable characteristics for touch screen panels.

  5. Copper coated carbon fiber reinforced plastics for high and ultra high vacuum applications

    CERN Document Server

    Burri, F; Feusi, P; Henneck, R; Kirch, K; Lauss, B; Ruettimann, P; Schmidt-Wellenburg, P; Schnabel, A; Voigt, J; Zenner, J; Zsigmond, G

    2013-01-01

    We have used copper-coated carbon fiber reinforced plastic (CuCFRP) for the construction of high and ultra-high vacuum recipients. The vacuum performance is found to be comparable to typical stainless steel used for this purpose. In test recipients we have reached pressures of 2E-8 mbar and measured a desorption rate of 1E-11 mbar*liter/s/cm^2; no degradation over time (2 years) has been found. Suitability for baking has been found to depend on the CFRP production process, presumably on the temperature of the autoclave curing. Together with other unique properties of CuCFRP such as low weight and being nearly non-magnetic, this makes it an ideal material for many high-end vacuum applications.

  6. Decomposition of 2-chloroethylethylsulfide on copper oxides to detoxify polymer-based spherical activated carbons from chemical warfare agents.

    Science.gov (United States)

    Fichtner, S; Hofmann, J; Möller, A; Schrage, C; Giebelhausen, J M; Böhringer, B; Gläser, R

    2013-11-15

    For the decomposition of chemical warfare agents, a hybrid material concept was applied. This consists of a copper oxide-containing phase as a component with reactive functionality supported on polymer-based spherical activated carbon (PBSAC) as a component with adsorptive functionality. A corresponding hybrid material was prepared by impregnation of PBSAC with copper(II)nitrate and subsequent calcination at 673K. The copper phase exists predominantly as copper(I)oxide which is homogeneously distributed over the PBSAC particles. The hybrid material containing 16 wt.% copper on PBSAC is capable of self-detoxifying the mustard gas surrogate 2-chloroethylethylsulfide (CEES) at room temperature. The decomposition is related to the breakthrough behavior of the reactant CEES, which displaces the reaction product ethylvinylsulfide (EVS). This leads to a combined breakthrough of CEES and EVS. The decomposition of CEES is shown to occur catalytically over the copper-containing PBSAC material. Thus, the hybrid material can even be considered to be self-cleaning.

  7. Predicting Copper Speciation in Estuarine Waters-Is Dissolved Organic Carbon a Good Proxy for the Presence of Organic Ligands?

    Science.gov (United States)

    Pearson, Holly B C; Comber, Sean D W; Braungardt, Charlotte; Worsfold, Paul J

    2017-02-21

    A new generation of speciation-based aquatic environmental quality standards (EQS) for metals have been developed using models to predict the free metal ion concentration, the most ecologically relevant form, to set site-specific values. Some countries such as the U.K. have moved toward this approach by setting a new estuarine and marine water EQS for copper, based on an empirical relationship between copper toxicity to mussels (Mytilus sp.) and ambient dissolved organic carbon (DOC) concentrations. This assumes an inverse relationship between DOC and free copper ion concentration owing to complexation by predominantly organic ligands. At low DOC concentrations, the new EQS is more stringent, but above 162 μM DOC it is higher than the previous value. However, the relationship between DOC and copper speciation is poorly defined in estuarine waters. This research discusses the influence of DOC from different sources on copper speciation in estuaries and concludes that DOC is not necessarily an accurate predictor of copper speciation. Nevertheless, the determination of ligand strength and concentrations by Competitive Ligand Exchange Adsorptive Cathodic Stripping Voltammetry enabled the prediction of the free metal ion concentration within an order of magnitude for estuarine waters by using a readily available metal speciation model (Visual MINTEQ).

  8. The Uses of Copper and Zinc Aluminates to Capture and Convert Carbon dioxide to Syn-gas at Higher Temperature

    Directory of Open Access Journals (Sweden)

    R.Y. Raskar

    2014-03-01

    Full Text Available The uses of copper and zinc aluminates to capture and convert the CO2 to syn-gas were studied at higher temperatures. The samples of copper and zinc aluminates were prepared by solid-solid fusion method by calcining in air at 900 oC for 3 h. Those samples were characterized by acidity/alkalinity, surface area, XRD pattern, IR, SEM images and screening to capture CO2 at the different temperatures. The phases Cu2O, CuO, ZnO, CuAl2O4 and ZnAl2O4 were found to be in the samples of zinc and copper aluminates. Acidity and surface area of the samples of copper and zinc aluminates were found to be in the ranges from 0.063 to 9.37 mmol g-1 and 3.04 to 11.8 m2 g-1, respectively. The captured CO2 by the samples of copper and zinc aluminates was found to be 19.92 to 31.52 wt% for the temperature range 40 to 850 oC. The captured CO2 at 550 oC by variable Zn/Al and Cu/Al mol ratio from 0.5 to 6 of the samples of copper and zinc aluminates was found to be 12.81 to 18.04 wt%. The reduction of carbon dioxide by zinc and copper aluminates was observed. The conversion of CO2 by methane over variable mol ratio of Cu/Al and Zn/Al in copper and zinc aluminates, respectively, at 500 oC showed the production of syn-gas by using the gas hourly space velocities (GHSV 12000, 12000 and 6000 ml. h-1. g-1 of helium, CO2 and methane. The conversions of CO2 by methane over the samples of zinc and copper aluminates were studied at different mol ratios of CO2 to methane.  © 2014 BCREC UNDIP. All rights reservedReceived: 13rd May 2013; Revised: 8th November 2013; Accepted: 8th November 2013[How to Cite: Raskar, R.Y., Gaikwad, A.G. (2014. The Uses of Copper and Zinc Aluminates to Cap-ture and Convert Carbon Dioxide to Syn-gas at Higher Temperature. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1: 1-15. (doi:10.9767/bcrec.9.1.4899.1-15[Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.1.4899.1-15

  9. Three-dimensional porous hollow fibre copper electrodes for efficient and high-rate electrochemical carbon dioxide reduction.

    Science.gov (United States)

    Kas, Recep; Hummadi, Khalid Khazzal; Kortlever, Ruud; de Wit, Patrick; Milbrat, Alexander; Luiten-Olieman, Mieke W J; Benes, Nieck E; Koper, Marc T M; Mul, Guido

    2016-01-01

    Aqueous-phase electrochemical reduction of carbon dioxide requires an active, earth-abundant electrocatalyst, as well as highly efficient mass transport. Here we report the design of a porous hollow fibre copper electrode with a compact three-dimensional geometry, which provides a large area, three-phase boundary for gas-liquid reactions. The performance of the copper electrode is significantly enhanced; at overpotentials between 200 and 400 mV, faradaic efficiencies for carbon dioxide reduction up to 85% are obtained. Moreover, the carbon monoxide formation rate is at least one order of magnitude larger when compared with state-of-the-art nanocrystalline copper electrodes. Copper hollow fibre electrodes can be prepared via a facile method that is compatible with existing large-scale production processes. The results of this study may inspire the development of new types of microtubular electrodes for electrochemical processes in which at least one gas-phase reactant is involved, such as in fuel cell technology.

  10. Three-dimensional porous hollow fibre copper electrodes for efficient and high-rate electrochemical carbon dioxide reduction

    Science.gov (United States)

    Kas, Recep; Hummadi, Khalid Khazzal; Kortlever, Ruud; de Wit, Patrick; Milbrat, Alexander; Luiten-Olieman, Mieke W. J.; Benes, Nieck E.; Koper, Marc T. M.; Mul, Guido

    2016-02-01

    Aqueous-phase electrochemical reduction of carbon dioxide requires an active, earth-abundant electrocatalyst, as well as highly efficient mass transport. Here we report the design of a porous hollow fibre copper electrode with a compact three-dimensional geometry, which provides a large area, three-phase boundary for gas-liquid reactions. The performance of the copper electrode is significantly enhanced; at overpotentials between 200 and 400 mV, faradaic efficiencies for carbon dioxide reduction up to 85% are obtained. Moreover, the carbon monoxide formation rate is at least one order of magnitude larger when compared with state-of-the-art nanocrystalline copper electrodes. Copper hollow fibre electrodes can be prepared via a facile method that is compatible with existing large-scale production processes. The results of this study may inspire the development of new types of microtubular electrodes for electrochemical processes in which at least one gas-phase reactant is involved, such as in fuel cell technology.

  11. Using copper substrate to enhance electron field emission properties of carbon nanotube/diamond double-layered structure

    Science.gov (United States)

    Yang, Lezhi; Sujith Kumar, C. S.; Li, Yuan-shi; Niakan, Hamid; Zhang, Chunzi; Hirose, Akira; Aravind, Suresh; Yang, Qiaoqin

    2015-01-01

    Vertically aligned carbon nanotube (CNT)/diamond double-layered structure was synthesized on copper (Cu) substrate by hot-filament chemical vapor deposition. The structure was characterized by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The results show that the diamond layer has good adhesion to the Cu substrate and the CNTs have direct contact with the diamond layer. Field electron emission measurement shows that the double-layered structure on copper has very good emission stability and a much lower turn-on field than that on silicon (Si).

  12. Adsorption and oxidation of SO₂in a fixed-bed reactor using activated carbon produced from oxytetracycline bacterial residue and impregnated with copper.

    Science.gov (United States)

    Zhou, Baohua; Yu, Lei; Song, Hanning; Li, Yaqi; Zhang, Peng; Guo, Bin; Duan, Erhong

    2015-02-01

    The SO₂removal ability (including adsorption and oxidation ability) of activated carbon produced from oxytetracycline bacterial residue and impregnated with copper was investigated. The activated carbon produced from oxytetracycline bacterial residue and modified with copper was characterized by x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The effects of the catalysts, SO₂concentration, weight hourly space velocity, and temperature on the SO₂adsorption and oxidation activity were evaluated. Activated carbon produced from oxytetracycline bacterial residue and used as catalyst supports for copper oxide catalysts provided high catalytic activity for the adsorbing and oxidizing of SO₂from flue gases.

  13. Ceramic carbon electrode-based anodes for use in the copper-chlorine thermochemical cycle

    Energy Technology Data Exchange (ETDEWEB)

    Ranganathan, S.; Easton, E.B. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Science

    2009-07-01

    A thermochemical cycle is a process by which water is decomposed into hydrogen and oxygen through a series of chemical reactions. The chemicals that are used in these reactions are regenerated and recycled during the process. Sol-gel chemistry is becoming more common for the synthesis of electrode materials. The sol-gel reaction can be conducted in the presence of a carbon black to form a ceramic carbon electrode (CCE). The resultant CCE structure contains electronically conductive carbon particle pathways that are bound together through the ceramic binder, which can also promote ion transport. The CCE structure also has a high active surface area and is chemically and thermally robust. This paper presented an investigation of CCE materials prepared using 3-aminopropyl trimethoxysilane. Several electrochemical experiments including cyclic voltammetry and electrochemical impedance spectroscopy were performed to characterize their suitability as anode electrode materials for use in the electrochemical step of the copper-chlorine thermochemical cycle. Subsequent experiments included the manipulation of the relative ratio of organosilane carbon precursors to gauge its impact on electrode properties and performance. An overview of the materials characterization and electrochemical measurements were also presented. Specifically, the paper presented the experiment with particular reference to the CCE preparation; electrochemical experiments; thermal analysis; and scanning electron microscopy. Results were also provided. These included TGA analysis; scanning electron microscopy analysis; electrochemical characterization; and anodic polarization. Characterization of these CCE material demonstrated that they had good thermal stability, could be used at high temperatures, and were therefore, very promising anode materials. 15 refs., 7 figs.

  14. Thermo-physical Properties of Continuous Carbon Fiber Reinforced Copper Matrix Composites

    Institute of Scientific and Technical Information of China (English)

    曹金华; 黄俊波; 陈先有

    2007-01-01

    Continuous carbon fiber reinforced copper matrix composites with 70%(volume fraction)of carbon fibers prepared by squeeze casting technique have been used for investigation of the coefficient of thermal expansion(CTE)and thermal conductivity.Thermo-physical properties have been measured in both, longitudinal and transversal directions to the fiber orientation.The results showed that Cf/Cu composites may be a suitable candidate for heat sinks because of its good thermo-physical properties e.g.the low CTE(4.18×10-6/K)in longitudinal orientation and(14.98×10-6/K)in transversal orientation at the range of 20-50℃,a good thermal conductivity(87.2 W/m·K)in longitudinal orientation and(58.2 W/m·K)in transversal orientation.Measured CTE and thermal conductivity values are compared with those predicted by several well-known models.Eshelby model gave better results for prediction of the CTE and thermal conductivity of the unidirectional composites.

  15. Nitrite Oxidation with Copper-Cobalt Nanoparticles on Carbon Nanotubes Doped Conducting Polymer PEDOT Composite.

    Science.gov (United States)

    Wang, Junjie; Xu, Guiyun; Wang, Wei; Xu, Shenghao; Luo, Xiliang

    2015-09-01

    Copper-cobalt bimetal nanoparticles (Cu-Co) have been electrochemically prepared on glassy carbon electrodes (GCEs), which were electrodeposited with conducting polymer nanocomposites of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with carbon nanotubes (CNTs). Owing to their good conductivity, high mechanical strength, and large surface area, the PEDOT/CNTs composites offered excellent substrates for the electrochemical deposition of Cu-Co nanoparticles. As a result of their nanostructure and the synergic effect between Cu and Co, the Cu-Co/PEDOT/CNTs composites exhibited significantly enhanced catalytic activity towards the electrochemical oxidation of nitrite. Under optimized conditions, the nanocomposite-modified electrodes had a fast response time within 2 s and a linear range from 0.5 to 430 μm for the detection of nitrite, with a detection limit of 60 nm. Moreover, the Cu-Co/PEDOT/CNTs composites were highly stable, and the prepared nitrite sensors could retain more than 96 % of their initial response after 30 days.

  16. Uniform Dispersion of Multiwalled Carbon Nanotubes in Copper Matrix Nanocomposites Using Metal Injection Molding Technique

    Directory of Open Access Journals (Sweden)

    Ali Samer Muhsan

    2013-01-01

    Full Text Available This work presents a novel fabrication approach of multiwalled carbon nanotubes (MWNTs reinforced copper (Cu matrix nanocomposites. A combination of nanoscale dispersion of functionalized MWNTs in low viscose media of dissolved paraffin wax under sonication treatment followed by metal injection molding (MIM technique was adopted. MWNTs contents were varied from 0 to 10 vol.%. Information about the degree of purification and functionalization processes, evidences on the existence of the functional groups, effect of sonication time on the treated MWNTs, and microstructural analysis of the fabricated Cu/MWNTs nanocomposites were determined using TEM, EDX, FESEM, and Raman spectroscopy analysis. The results showed that the impurities of the pristine MWNTs such as Fe, Ni catalyst, and the amorphous carbon have been significantly removed after purification process. Meanwhile, FESEM and TEM observations showed high stability of MWNTs at elevated temperatures and uniform dispersion of MWNTs in Cu matrix at different volume fractions and sintering temperatures (950, 1000 & 1050°C. The experimentally measured thermal conductivities of Cu/MWNTs nanocomposites showed remarkable increase (11.25% higher than sintered pure Cu with addition of 1 vol.% MWNTs, and slight decrease below the value of sintered Cu at 5 and 10 vol.% MWNTs.

  17. Synthesis of isocoumarins through three-component couplings of arynes, terminal alkynes, and carbon dioxide catalyzed by an NHC-copper complex.

    Science.gov (United States)

    Yoo, Woo-Jin; Nguyen, Thanh V Q; Kobayashi, Shū

    2014-09-15

    A copper-catalyzed multicomponent coupling reaction between in situ generated ortho-arynes, terminal alkynes, and carbon dioxide was developed to access isocoumarins in moderate to good yields. The key to this CO2-incorporating reaction was the use of a versatile N-heterocyclic carbene/copper complex that was able to catalyze multiple transformations within the three-component reaction.

  18. Electrical Resistivity, Tribological Behaviour of Multiwalled Carbon Nanotubes and Nanoboron Carbide Particles Reinforced Copper Hybrid Composites for Pantograph Application

    Directory of Open Access Journals (Sweden)

    N. Selvakumar

    2016-01-01

    Full Text Available This work focuses on the influence and contribution of multiwalled carbon-nanotube (MWCNT–boron carbide (B4C to the mechanical and tribological properties of copper matrix composites. Different weight fractions of nano- B4C-containing fixed-weight fractions of MWCNT-reinforced copper composites were prepared using the entrenched cold-press sintering method of powder metallurgy. The wear losses of sintered Cu–MWCNT–B4C composites were investigated by conducting sliding tests in a pin-on-disc apparatus. The addition of reinforcements showed enhancements in the hardness and wear properties of the composites due to the uniform dispersion of the secondary reinforcement in the copper matrix and the self-lubricating effect of the MWCNTs. The effects of the nanoparticle distribution in the matrix, the worn surface morphology, and the elemental composition of the composites were characterized using high-resolution scanning electron microscopy and X-ray diffraction analysis. The electrical resistivity of the fabricated copper hybrid composite preforms was evaluated using a four-point probe tester. Our results highlight the use of experiential reinforcing limits of B4C on the wear and electrical and mechanical behaviour of copper composites.

  19. Enantioselective Synthesis of All-Carbon Quaternary Stereogenic Centers via Copper-Catalyzed Asymmetric Allylic Alkylation of (Z)-Allyl Bromides with Organolithium Reagents

    NARCIS (Netherlands)

    Fananas-Mastral, Martin; Vitale, Romina; Perez, Manuel; Feringa, Ben L.

    2015-01-01

    A copper/phosphoramidite catalyzed asymmetric allylic alkylation of Z trisubstituted allyl bromides with organolithium reagents is reported. The reaction affords all-carbon quaternary stereogenic centers in high yields and very good regio- and enantioselectivity. This systematic study illustrates

  20. [Effects of heavy metal (copper and cadmium) coupled with Ulca pertusa on marine inorganic carbon system in simulated experiments].

    Science.gov (United States)

    Zheng, Guo-xia; Song, Jin-ming; Dai, Ji-cui

    2006-12-01

    Simulated experiments coupled with ocean biota dynamics were performed in laboratory. In these experiments, effects of heavy metal (copper and cadmium) coupled with Ulca pertusa on marine inorganic carbon system and CO2 fluxes were investigated. The results indicated that concentration changes (delta) of components in carbon dioxide system with time scale were correlated with the concentrations and kinds of heavy metal. In copper groups and cadmium groups (0.1 micromol x L(-1) and 1 micromol x L(-1)), DIC HCO3- and PCO2 significantly decreased comparing to the control experiment data( p = 0.01). However, when the heavy metal infusions were higher than the "critical concentration", the above mentioned parameters increased with time scale and their increments followed the uptrend with increasing heavy metal concentrations. The "critical concentration" in copper groups was much lower than that in cadmium groups, which attributed to the tolerance diversity of Ulca pertusa to copper and cadmium. Furthermore, CO2 fluxes under the influences of heavy metal were also regularly changed with time. Sea waters with low infusions of heavy metal represented as sinks to the atmosphere CO2. These sinks would probably convert into CO2 sources after a period of time. Sea waters with comparatively high amount of heavy metal were always to be CO2 sources, and their release fluxes of CO2 augmented along with the increasing infusions of heavy metal.

  1. Facile preparation of carbon wrapped copper telluride nanowires as high performance anodes for sodium and lithium ion batteries

    Science.gov (United States)

    Yu, Hong; Yang, Jun; Geng, Hongbo; Chao Li, Cheng

    2017-04-01

    Uniform carbon wrapped copper telluride nanowires were successfully prepared by using an in situ conversion reaction. The length of these nanowires is up to several micrometers and the width is around 30–40 nm. The unique one dimensional structure and the presence of conformal carbon coating of copper telluride greatly accommodate the large volumetric changes during cycling, significantly increase the electrical conductivity and reduce charge transfer resistance. The copper telluride nanowires show promising performance in a lithium ion battery with a discharge capacity of 130.2 mA h g‑1 at a high current density of 6.0 A g‑1 (26.74 C) and a stable cycling performance of 673.3 mA h g‑1 during the 60th cycle at 100 mA g‑1. When evaluated as anode material for a sodium ion battery, the copper telluride nanowires deliver a reversible capacity of 68.1 mA h g‑1 at 1.0 A g‑1 (∼4.46 C) and have a high capacity retention of 177.5 mA h g‑1 during the 500th cycle at 100 mA g‑1.

  2. Ultrasonic test of carbon composite/copper joints in the ITER divertor

    Energy Technology Data Exchange (ETDEWEB)

    Roccella, S., E-mail: selanna.roccella@enea.it [Associazione ENEA-Euratom sulla Fusione, C.R. Frascati, 00044 Frascati, RM (Italy); Cacciotti, E. [Associazione ENEA-Euratom sulla Fusione, C.R. Frascati, 00044 Frascati, RM (Italy); Candura, D. [Ansaldo Nucleare S.p.A., C. so F.M. Perrone 25, 16152 Genoa (Italy); Mancini, A.; Pizzuto, A.; Reale, A. [Associazione ENEA-Euratom sulla Fusione, C.R. Frascati, 00044 Frascati, RM (Italy); Tatì, A. [Associazione Euratom-ENEA sulla Fusione, C.R. Casaccia, Via Anguillarese 301, 00123 Santa Maria di Galeria, RM (Italy); Visca, E. [Associazione ENEA-Euratom sulla Fusione, C.R. Frascati, 00044 Frascati, RM (Italy)

    2013-10-15

    Highlights: • ENEA developed and tested a specimen for the simulation of defects at the interface between CFC and copper. • The use of an ultrasonic technique properly set permitted to highlight and size with high accuracy the defects. • The technology developed could be employed successfully in the production of these components for high heat flux applications. -- Abstract: The vertical targets of the ITER divertor consist of high flux units (HFU) actively cooled: CuCrZr tubes armoured by tungsten and carbon/carbon fibre composite (CFC). The armour is obtained with holed parallelepiped blocks, called monoblocks, previously prepared and welded onto the tubes by means diffusion bonding. The monoblock preparation consists in the casting of a layer of copper oxygen free (Cu OFHC) inside the monoblock hole. Each HFU is covered with more than 100 monoblocks that have to be joined simultaneously to the tube. Therefore, it is very important to individuate any defects present in the casting of Cu OFHC or at the interface with the CFC before the monoblocks are installed on the units. This paper discusses the application of non-destructive testing by ultrasound (US) method for the control of the joining interfaces between CFC monoblocks and Cu OFHC, before the brazing on the CrCrZr tube. In ENEA laboratory an ultrasonic technique (UT) suitable for the control of these joints with size and geometry according to the ITER specifications has been developed and widely tested. Real defects in this type of joints are, however, still hardly detected by UT. The CFC surface has to be machined to improve the mechanical strength of the joint. This results in a surface not perpendicular to the ultrasonic wave. Moreover, CFC is characterized by high acoustic attenuation of the ultrasonic wave and then it is not easy to get information regarding the Cu/CFC bonding. Nevertheless, the UT sharpness and simplicity pushes to perform some further study. With this purpose, a sample with

  3. Electrocatalytic O2 Reduction at a Bio-inspired Mononuclear Copper Phenolato Complex Immobilized on a Carbon Nanotube Electrode.

    Science.gov (United States)

    Gentil, Solène; Serre, Doti; Philouze, Christian; Holzinger, Michael; Thomas, Fabrice; Le Goff, Alan

    2016-02-12

    An original copper-phenolate complex, mimicking the active center of galactose oxidase, featuring a pyrene group was synthesized. Supramolecular pi-stacking allows its efficient and soft immobilization at the surface of a Multi-Walled Carbon Nanotube (MWCNT) electrode. This MWCNT-supported galactose oxidase model exhibits a 4 H(+)/4 e(-) electrocatalytic activity towards oxygen reduction at a redox potential of 0.60 V vs. RHE at pH 5.

  4. Effects of water hardness, alkalinity, and dissolved organic carbon on the toxicity of copper to the lateral line of developing fish.

    Science.gov (United States)

    Linbo, Tiffany L; Baldwin, David H; McIntyre, Jenifer K; Scholz, Nathaniel L

    2009-07-01

    Conventional water chemistry parameters such as hardness, alkalinity, and organic carbon are known to affect the acutely lethal toxicity of copper to fish and other aquatic organisms. In the present study, we investigate the influence of these water chemistry parameters on short-term (3 h), sublethal (0-40 microg/L) copper toxicity to the peripheral mechanosensory system of larval zebrafish (Danio rerio) using an in vivo fluorescent marker of lateral line sensory neuron (hair cell) integrity. We studied the influence of hardness (via CaCl2, MgSO4, or both at a 2:1 molar ratio), sodium (via NaHCO3 or NaCl), and organic carbon on copper-induced neurotoxicity to zebrafish lateral line neurons over a range of environmentally relevant water chemistries. For all water parameters but organic carbon, the reductions in copper toxicity, although statistically significant, were small. Increasing organic carbon across a range of environmentally relevant concentrations (0.1-4.3 mg/L) increased the EC50 for copper toxicity (the effective concentration resulting in a 50% loss of hair cells) from approximately 12 microg/L to approximately 50 microg/L. Finally, we used an ionoregulatory-based biotic ligand model to compare copper toxicity mediated by targets in the fish gill and lateral line. Relative to copper toxicity via the gill, we find that individual water chemistry parameters are less influential in terms of reducing cytotoxic impacts to the mechanosensory system.

  5. Obtenção de filmes espessos de seleneto de cobre sobre carbono vítreo, ouro, titânio e cobre Obtaining copper selenide thick films on vitreous carbon, gold, titanium and copper

    OpenAIRE

    Adriano César Rabelo; Tatiane Moraes Arantes; Otávio Luiz Bottecchia

    2007-01-01

    Copper selenide (berzelianite) films were prepared on the title substrates using the chemical bath deposition technique (CBD). Film composition was determined by energy dispersion of x-rays. The kinetics of film growth is parabolic and film adherence limits the film thickness. On titanium, copper selenide forms islands that do not completely cover the surface, unless the substrate is prepared with a tin oxide layer; film composition also depends on the titanium oxide layer. On vitreous carbon...

  6. Copper Nanoparticle-Incorporated Carbon Fibers as Free-Standing Anodes for Lithium-Ion Batteries.

    Science.gov (United States)

    Han, Pan; Yuan, Tao; Yao, Long; Han, Zhuo; Yang, Junhe; Zheng, Shiyou

    2016-12-01

    Copper-incorporated carbon fibers (Cu/CF) as free-standing anodes for lithium-ion batteries are prepared by electrospinning technique following with calcination at 600, 700, and 800 °C. The structural properties of materials are characterized by X-ray diffraction (XRD), Raman, thermogravimetry (TGA), scanning electron microscopy (SEM), transmission electron microscope (TEM), and energy dispersive X-ray spectrometry (EDS). It is found that the Cu/CF composites have smooth, regular, and long fibrous morphologies with Cu nanoparticles uniformly dispersed in the carbon fibers. As free-standing anodes, the unique structural Cu/CF composites show stable and high reversible capacities, together with remarkable rate and cycling capabilities in Li-ion batteries. The Cu/CF calcined at 800 °C (Cu/CF-800) has the highest charge/discharge capacities, long-term stable cycling performance, and excellent rate performance; for instance, the Cu/CF-800 anode shows reversible charge/discharge capacities of around 800 mAh g(-1) at a current density of 100 mA g(-1) with stable cycling performance for more than 250 cycles; even when the current density increases to 2 A g(-1), the Cu/CF-800 anode can still deliver a capacity of 300 mAh g(-1). This excellent electrochemical performance is attributed to the special 1D structure of Cu/CF composites, the enhanced electrical conductivity, and more Li(+) active positions by Cu nanoinclusion.

  7. Novel Carbon Dioxide Microsensor Based on Tin Oxide Nanomaterial Doped With Copper Oxide

    Science.gov (United States)

    Xu, Jennifer C.; Hunter, Gary W.; Lukco, Dorothy; Liu, Chung-Chiun; Ward, Benjamin J.

    2008-01-01

    Carbon dioxide (CO2) is one of the major indicators of fire and therefore its measurement is very important for low-false-alarm fire detection and emissions monitoring. However, only a limited number of CO2 sensing materials exist due to the high chemical stability of CO2. In this work, a novel CO2 microsensor based on nanocrystalline tin oxide (SnO2) doped with copper oxide (CuO) has been successfully demonstrated. The CuO-SnO2 based CO2 microsensors are fabricated by means of microelectromechanical systems (MEMS) technology and sol-gel nanomaterial-synthesis processes. At a doping level of CuO: SnO2 = 1:8 (molar ratio), the resistance of the sensor has a linear response to CO2 concentrations for the range of 1 to 4 percent CO2 in air at 450 C. This approach has demonstrated the use of SnO2, typically used for the detection of reducing gases, in the detection of an oxidizing gas.

  8. Integrated Behavior of Carbon and Copper Alloy Heat Sink Under Different Heat Loads and Cooling Conditions

    Institute of Scientific and Technical Information of China (English)

    Li Hua; Li Jiangang; Chen Junling; Hu Jiansheng

    2005-01-01

    An actively water-cooled limiter has been designed for the long pulse operation of an HT-7 device, by adopting an integrated structure-doped graphite and a copper alloy heat sink with a super carbon sheet serving as a compliant layer between them. The behaviors of the integrated structure were evaluated in an electron beam facility under different heat loads and cooling conditions. The surface temperature and bulk temperature distribution were carefully measured by optical pyrometers and thermocouples under a steady state heat flux of 1 to 5 MW/m2 and a water flow rate of 3 m3/h, 4.5 m3/h and 6 m3/h, respectively. It was found that the surface temperature increased rapidly with the heat flux rising, but decreased only slightly with the water flow rate rising. The surface temperature reached approximately 1200℃ at 5 MW/m2 of heat flux and 6 ms/h of water flow. The primary experimental results indicate that the integrated design meets the requirements for the heat expelling capacity of the HT-7 device. A set of numerical simulations was also completed, whose outcome was in good accord with the experimental results.

  9. Preparation,Electrochemical Behavior and Electrocatalytic Activity of a Copper Hexacyanoferrate Modified Ceramic Carbon Electrode

    Institute of Scientific and Technical Information of China (English)

    YU,Hao; ZHENG,Jian-Bin

    2007-01-01

    A copper hexacyanoferrate modified ceramic carbon electrode(CuHCF/CCE)had been prepared by two-step sol-gel technique and characterized using electrochemical methods.The resulting modified electrode showed a pair of well-defined surface waves in the potential range of 0.40 to 1.0 V with the formal potential of 0.682 V (vs.SCE)in 0.050 mol·dm-3 HOAc-NaOAc buffer containing 0.30 mol·dm-3 KCI.The charge transfer coefficient (α) and charge transfer rate constant(Ks)for the modified electrode were calculated.The electrocatalytic activity of this modified electrode to hydrazine was also investigated,and chronoamperometry was exploited to conveniently determine the diffusion coefficient(D)of hydrazine in solution and the catalytic rate constant(Kcat).Finally,hydrazine was determined with amperometry using the resulting modified electrode.The calibration plot for hydrazine determination was linear in 3.0×10-6-7.5×10-4 mol·dm-3 with the detection limit of 8.0×10-7 mol·dm-3.This modified electrode had some advantages over the modified film electrodes constructed by the conventional methods,such as renewable surface,good long-term stability,excellent catalytic activity and short response time to hydrazine.

  10. Non-Enzymatic Glucose Sensing Using Carbon Quantum Dots Decorated with Copper Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Houcem Maaoui

    2016-10-01

    Full Text Available Perturbations in glucose homeostasis is critical for human health, as hyperglycemia (defining diabetes leads to premature death caused by macrovascular and microvascular complications. However, the simple and accurate detection of glucose in the blood at low cost remains a challenging task, although it is of great importance for the diagnosis and therapy of diabetic patients. In this work, carbon quantum dots decorated with copper oxide nanostructures (CQDs/Cu2O are prepared by a simple hydrothermal approach, and their potential for electrochemical non-enzymatic glucose sensing is evaluated. The proposed sensor exhibits excellent electrocatalytic activity towards glucose oxidation in alkaline solutions. The glucose sensor is characterized by a wide concentration range from 6 µM to 6 mM, a sensitivity of 2.9 ± 0.2 µA·µM−1·cm−2, and a detection limit of 6 µM at a signal-to-noise ratio S/N = 3. The sensors are successfully applied for glucose determination in human serum samples, demonstrating that the CQDs/Cu2O-based glucose sensor satisfies the requirements of complex sample detection with adapted potential for therapeutic diagnostics.

  11. Thermal Properties of Carbon Nanotube–Copper Composites for Thermal Management Applications

    Directory of Open Access Journals (Sweden)

    Jia Chengchang

    2010-01-01

    Full Text Available Abstract Carbon nanotube–copper (CNT/Cu composites have been successfully synthesized by means of a novel particles-compositing process followed by spark plasma sintering (SPS technique. The thermal conductivity of the composites was measured by a laser flash technique and theoretical analyzed using an effective medium approach. The experimental results showed that the thermal conductivity unusually decreased after the incorporation of CNTs. Theoretical analyses revealed that the interfacial thermal resistance between the CNTs and the Cu matrix plays a crucial role in determining the thermal conductivity of bulk composites, and only small interfacial thermal resistance can induce a significant degradation in thermal conductivity for CNT/Cu composites. The influence of sintering condition on the thermal conductivity depended on the combined effects of multiple factors, i.e. porosity, CNTs distribution and CNT kinks or twists. The composites sintered at 600°C for 5 min under 50 MPa showed the maximum thermal conductivity. CNT/Cu composites are considered to be a promising material for thermal management applications.

  12. Thermal Properties of Carbon Nanotube–Copper Composites for Thermal Management Applications

    Science.gov (United States)

    2010-01-01

    Carbon nanotube–copper (CNT/Cu) composites have been successfully synthesized by means of a novel particles-compositing process followed by spark plasma sintering (SPS) technique. The thermal conductivity of the composites was measured by a laser flash technique and theoretical analyzed using an effective medium approach. The experimental results showed that the thermal conductivity unusually decreased after the incorporation of CNTs. Theoretical analyses revealed that the interfacial thermal resistance between the CNTs and the Cu matrix plays a crucial role in determining the thermal conductivity of bulk composites, and only small interfacial thermal resistance can induce a significant degradation in thermal conductivity for CNT/Cu composites. The influence of sintering condition on the thermal conductivity depended on the combined effects of multiple factors, i.e. porosity, CNTs distribution and CNT kinks or twists. The composites sintered at 600°C for 5 min under 50 MPa showed the maximum thermal conductivity. CNT/Cu composites are considered to be a promising material for thermal management applications. PMID:20672107

  13. Thermal Properties of Carbon Nanotube-Copper Composites for Thermal Management Applications

    Science.gov (United States)

    Chu, Ke; Guo, Hong; Jia, Chengchang; Yin, Fazhang; Zhang, Ximin; Liang, Xuebing; Chen, Hui

    2010-05-01

    Carbon nanotube-copper (CNT/Cu) composites have been successfully synthesized by means of a novel particles-compositing process followed by spark plasma sintering (SPS) technique. The thermal conductivity of the composites was measured by a laser flash technique and theoretical analyzed using an effective medium approach. The experimental results showed that the thermal conductivity unusually decreased after the incorporation of CNTs. Theoretical analyses revealed that the interfacial thermal resistance between the CNTs and the Cu matrix plays a crucial role in determining the thermal conductivity of bulk composites, and only small interfacial thermal resistance can induce a significant degradation in thermal conductivity for CNT/Cu composites. The influence of sintering condition on the thermal conductivity depended on the combined effects of multiple factors, i.e. porosity, CNTs distribution and CNT kinks or twists. The composites sintered at 600°C for 5 min under 50 MPa showed the maximum thermal conductivity. CNT/Cu composites are considered to be a promising material for thermal management applications.

  14. Adsorption of carbon dioxide, methane and nitrogen on an ultramicroporous copper metal-organic framework.

    Science.gov (United States)

    Wu, Xiaofei; Yuan, Bin; Bao, Zongbi; Deng, Shuguang

    2014-09-15

    An ultramicroporous copper metal-organic framework (Cu-MOF), Cu(hfipbb)(H2hfipbb)0.5 [H2hfipbb=4,4'-(hexafluoro-isopropylidene) bis(benzoic acid)] was successfully synthesized by a microwave-assisted method (1) with a shorter reaction time and higher MOFs yield. The obtained Cu-MOF sample was characterized with scanning electron microscopy for crystal structure, powder X-ray diffraction for phase structure, and carbon dioxide adsorption at 273 K for pore textural properties. Single-component adsorption (adsorption equilibrium and kinetics) of CO2, CH4, and N2 on 1 was measured using a Micromeritics ASAP 2020 adsorption porosimeter at 278, 298 and 318 K, and pressures up to 1 bar. Isosteric heats of adsorption, Henry's constants, and diffusion time constants were calculated and carefully analyzed. Adsorption equilibrium selectivity (α), adsorbent selection parameter for pressure swing adsorption processes (S), kinetic selectivity and combined separation selectivity (β) for CO2/CH4, CO2/N2 and CH4/N2 binary mixtures were estimated based on the single-component adsorption data. The relative high values of the adsorption selectivities suggest that Cu-MOF is a promising adsorbent for separating CO2/CH4, CO2/N2 and CH4/N2 gas pairs. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Effect of Alkaline-Stabilised Sewage Sludge on Extractable Organic Carbon and Copper in Soils

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An incubation experiment was conducted to evaluate the potential for water contamination with sludgederived organic substances and copper following land application of alkaline-stabilised sewage sludge. Two contrasting sludge-amended soils were studied. Both soils were previously treated with urban and rural alkaline biosolids separately at sludge application rates of 0, 30 and 120 t ha-1 fresh product. The air-dried soil/sludge mixtures were wetted with distilled water, maintained at 40 % of water-holding capacity and equilibrated for three weeks at 4 ℃ before extraction. Subsamples were extracted with either distilled water or 0.5 mol L-1 K2SO4 solution. The concentrations of organic C in the aqueous and chemical extracts were determined directly with a total organic carbon (TOC) analyser. The concentrations of Cu in the two extracts were also determined by atomic absorption spectrophotometry. The relationship between the two extractable organic C fractions was examined, together with that between extractable organic C concentration and extractable Cu concentration. Application of alkaline biosolids increased the concentrations of soil mobile organic substances and Cu. The results are discussed in terms of a possible increase in the potential for leaching of sludge-derived organics and Cu in the sludge-amended soils

  16. Novel electroless copper deposition on carbon fibers with environmentally friendly processes.

    Science.gov (United States)

    Byeon, Jeong Hoon; Kim, Jang-Woo

    2010-08-15

    A novel electroless deposition (ELD) of copper (Cu) on carbon fibers (CFs) with environmentally friendly processes, silver (Ag) aerosol activation and subsequent nonformaldehyde Cu ELD, was developed. Spark-generated Ag aerosol nanoparticles (approximately 10 nm in mode diameter) were deposited (48.4 microg Ag/g CF in activation intensity) onto the surfaces of CFs. After annealing (at 220 degrees C in a nitrogen atmosphere), the catalytically activated CFs were placed into a solution for Cu ELD (at 82 degrees C). Homogeneous Cu coating (approximately 5.1 nm/min) on CFs was achieved with 90 min of deposition and the corresponding mass deposition rate and Cu grain size for 30-90 min of deposition had ranges of 0.25-1.14 mg Cu/g CF-min and 14.8-37.2 nm, respectively. The porosity of CFs decreased by depositing the Cu for 30-90 min, and the specific surface area and pore volume of CFs decreased from 1536 to 1399 m(2)/g and from 0.65 to 0.57 cm(3)/g, respectively.

  17. 化学镀铜短碳纤维-铜-石墨复合材料的性能研究%Properties of Electroless Copper Plating on Short Carbon Fiber-Copper-Graphite Composite

    Institute of Scientific and Technical Information of China (English)

    许少凡; 许少平; 霍金元; 顾斌

    2012-01-01

    The surfaces of short carbon fibers were coated by electroless copper plating method, and the long carbon fibers coated by continuous electroplating copper method were cut short. The carbon fiber-copper-graphite composites with the two kinds of short carbon fibers and the copper-graphite composite without short carbon fibers were prepared by the powder metallurgy method. Their physical and mechanical properties were tested. The dry friction tests of the composites under sliding velocity of 15 m/s and load of 4. 9 N were conducted for 30 h . The results show that such properties of the electroless copper plating on short carbon fiber-copper-graphite composite as electric conductivity, hardness, bending strength and wear resistance are increased much more remarkably than those of the electroplating copper short carbon fiber-copper-graphite and copper-graphite composite without short carbon fiber.%本文采用化学镀铜法对短碳纤维表面进行镀铜,并用电镀法对长碳纤维表面进行连续镀铜后,再切割成镀铜短碳纤维.随后用粉末冶金法制备了含有这两种镀铜短碳纤维的碳纤维-铜-石墨复合材料和不含碳纤维的铜-石墨复合材料,对它们的物理和力学性能进行了测试,并在滑动速度为15 m/s、载荷为4.9N的干摩擦条件下进行了30 h磨损试验,结果表明:化学镀铜短碳纤维-铜-石墨复合材料的导电性、硬度、抗弯强度和耐磨性优于电镀铜短碳纤维-铜-石墨复合材料和不含碳纤维的铜-石墨复合材料.

  18. An important atomic process in the CVD growth of graphene: Sinking and up-floating of carbon atom on copper surface

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yingfeng [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, 102206 (China); Li, Meicheng, E-mail: mcli@ncepu.edu.cn [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, 102206 (China); Su Zhou Institute, North China Electric Power University, Suzhou, 215123 (China); Gu, TianSheng [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, 102206 (China); Bai, Fan [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001 (China); Yu, Yue; Trevor, Mwenya [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, 102206 (China); Yu, Yangxin [Department of Chemical Engineering, Tsinghua University, Beijing, 100084 (China)

    2013-11-01

    By density functional theory (DFT) calculations, the early stages of the growth of graphene on copper (1 1 1) surface are investigated. At the very first time of graphene growth, the carbon atom sinks into subsurface. As more carbon atoms are adsorbed nearby the site, the sunken carbon atom will spontaneously form a dimer with one of the newly adsorbed carbon atoms, and the formed dimer will up-float on the top of the surface. We emphasize the role of the co-operative relaxation of the co-adsorbed carbon atoms in facilitating the sinking and up-floating of carbon atoms. In detail: when two carbon atoms are co-adsorbed, their co-operative relaxation will result in different carbon–copper interactions for the co-adsorbed carbon atoms. This difference facilitates the sinking of a single carbon atom into the subsurface. As a third carbon atom is co-adsorbed nearby, it draws the sunken carbon atom on top of the surface, forming a dimer. Co-operative relaxations of the surface involving all adsorbed carbon atoms and their copper neighbors facilitate these sinking and up-floating processes. This investigation is helpful for the deeper understanding of graphene synthesis and the choosing of optimal carbon sources or process.

  19. PdCl2-loading mesoporous copper oxide as a novel and environmentally friendly catalyst for diethyl carbonate synthesis

    Science.gov (United States)

    Zhang, Pingbo; Zhou, Yan; Fan, Mingming; Jiang, Pingping

    2015-03-01

    PdCl2-loading mesoporous copper oxide (PdCl2/mCuO) catalysts were successfully synthesized via a hard template with copper carbonate basic (Cu2(OH)2CO3), cupric nitrate (Cu(NO3)2·3H2O) and copper citrate (Cu2C6H4O7·2.5H2O) as the copper(II) precursors, respectively. Their catalytic performances were investigated in the synthesis of diethyl carbonate (DEC) by oxidative carbonylation of ethanol with CO and O2. The catalysts were characterized by TGA, XRD, nitrogen adsorption-desorption analysis and SEM with the aim of establishing their composition, morphology and structure. It was observed that the catalysts all showed a good selectivity to diethyl carbonate. However, due to a better mesoporous structure such as a bigger surface area, more uniform particle size and less agglomeration, the PdCl2/mCuO-1 catalyst prepared with Cu2(OH)2CO3 precursor showed a better catalytic activity that the conversion of EtOH was about 4.8% and the STY of DEC was 97.1 mg g-1 h-1. This was because the highly developed mesoporous structure could generate a bigger surface area, which benefited the contact between reactants and active sites, improved the conversion of ethanol, and thus enhanced the catalytic performance. Furthermore, a synthetic procedure diagram about "wet impregnation" method of mesoporous CuO prepared with Cu2(OH)2CO3 precursor was given to illustrate these results intuitively.

  20. Study of Copper and Purine-Copper Complexes on Modified Carbon Electrodes by Cyclic and Elimination Voltammetry

    Directory of Open Access Journals (Sweden)

    Frantisek Jelen

    2008-01-01

    Full Text Available Using a paraffin impregnated graphite electrode (PIGE and mercury-modifiedpyrolytic graphite electrode with basal orientation (Hg-PGEb copper(II and Cu(II-DNApurine base solutions have been studied by cyclic (CV and linear sweep voltammetry(LSV in connection with elimination voltammetry with linear scan (EVLS. In chlorideand bromide solutions (pH 6, the redox process of Cu(II proceeded on PIGE with twocathodic and two anodic potentially separated signals. According to the eliminationfunction E4, the first cathodic peak corresponds to the reduction Cu(II e- → Cu(I withthe possibility of fast disproportionation 2Cu(I → Cu(II Cu(0. The E4 of the secondcathodic peak signalized an electrode process controlled by a surface reaction. Theelectrode system of Cu(II on Hg-PGEb in borate buffer (pH 9.2 was characterized by onecathodic and one anodic peak. Anodic stripping voltammetry (ASV on PIGE and cathodicstripping voltammetry (CSV on Hg-PGEb were carried out at potentials where thereduction of copper ions took place and Cu(I-purine complexes were formed. By usingASV and CSV in combination with EVLS, the sensitivity of Cu(I-purine complexdetection was enhanced relative to either ASV or CSV alone, resulting in higher peakcurrents of more than one order of magnitude. The statistical treatment of CE data wasused to determine the reproducibility of measurements. Our results show that EVLS inconnection with the stripping procedure is useful for both qualitative and quantitativemicroanalysis of purine derivatives and can also reveal details of studied electrodeprocesses.

  1. Study of Copper and Purine-Copper Complexes on Modified Carbon Electrodes by Cyclic and Elimination Voltammetry.

    Science.gov (United States)

    Trnkova, Libuse; Zerzankova, Lenka; Dycka, Filip; Mikelova, Radka; Jelen, Frantisek

    2008-01-24

    Using a paraffin impregnated graphite electrode (PIGE) and mercury-modifiedpyrolytic graphite electrode with basal orientation (Hg-PGEb) copper(II) and Cu(II)-DNApurine base solutions have been studied by cyclic (CV) and linear sweep voltammetry(LSV) in connection with elimination voltammetry with linear scan (EVLS). In chlorideand bromide solutions (pH 6), the redox process of Cu(II) proceeded on PIGE with twocathodic and two anodic potentially separated signals. According to the eliminationfunction E4, the first cathodic peak corresponds to the reduction Cu(II) e⁻ → Cu(I) withthe possibility of fast disproportionation 2Cu(I) → Cu(II) Cu(0). The E4 of the secondcathodic peak signalized an electrode process controlled by a surface reaction. Theelectrode system of Cu(II) on Hg-PGEb in borate buffer (pH 9.2) was characterized by onecathodic and one anodic peak. Anodic stripping voltammetry (ASV) on PIGE and cathodicstripping voltammetry (CSV) on Hg-PGEb were carried out at potentials where thereduction of copper ions took place and Cu(I)-purine complexes were formed. By usingASV and CSV in combination with EVLS, the sensitivity of Cu(I)-purine complexdetection was enhanced relative to either ASV or CSV alone, resulting in higher peakcurrents of more than one order of magnitude. The statistical treatment of CE data wasused to determine the reproducibility of measurements. Our results show that EVLS inconnection with the stripping procedure is useful for both qualitative and quantitativemicroanalysis of purine derivatives and can also reveal details of studied electrodeprocesses.

  2. Study of Copper and Purine-Copper Complexes on Modified Carbon Electrodes by Cyclic and Elimination Voltammetry

    Science.gov (United States)

    Trnkova, Libuse; Zerzankova, Lenka; Dycka, Filip; Mikelova, Radka; Jelen, Frantisek

    2008-01-01

    Using a paraffin impregnated graphite electrode (PIGE) and mercury-modified pyrolytic graphite electrode with basal orientation (Hg-PGEb) copper(II) and Cu(II)-DNA purine base solutions have been studied by cyclic (CV) and linear sweep voltammetry (LSV) in connection with elimination voltammetry with linear scan (EVLS). In chloride and bromide solutions (pH 6), the redox process of Cu(II) proceeded on PIGE with two cathodic and two anodic potentially separated signals. According to the elimination function E4, the first cathodic peak corresponds to the reduction Cu(II) + e- → Cu(I) with the possibility of fast disproportionation 2Cu(I) → Cu(II)+ Cu(0). The E4 of the second cathodic peak signalized an electrode process controlled by a surface reaction. The electrode system of Cu(II) on Hg-PGEb in borate buffer (pH 9.2) was characterized by one cathodic and one anodic peak. Anodic stripping voltammetry (ASV) on PIGE and cathodic stripping voltammetry (CSV) on Hg-PGEb were carried out at potentials where the reduction of copper ions took place and Cu(I)-purine complexes were formed. By using ASV and CSV in combination with EVLS, the sensitivity of Cu(I)-purine complex detection was enhanced relative to either ASV or CSV alone, resulting in higher peak currents of more than one order of magnitude. The statistical treatment of CE data was used to determine the reproducibility of measurements. Our results show that EVLS in connection with the stripping procedure is useful for both qualitative and quantitative microanalysis of purine derivatives and can also reveal details of studied electrode processes. PMID:27879715

  3. Photoinduced, Copper-Catalyzed Carbon-Carbon Bond Formation with Alkyl Electrophiles: Cyanation of Unactivated Secondary Alkyl Chlorides at Room Temperature.

    Science.gov (United States)

    Ratani, Tanvi S; Bachman, Shoshana; Fu, Gregory C; Peters, Jonas C

    2015-11-04

    We have recently reported that, in the presence of light and a copper catalyst, nitrogen nucleophiles such as carbazoles and primary amides undergo C-N coupling with alkyl halides under mild conditions. In the present study, we establish that photoinduced, copper-catalyzed alkylation can also be applied to C-C bond formation, specifically, that the cyanation of unactivated secondary alkyl chlorides can be achieved at room temperature to afford nitriles, an important class of target molecules. Thus, in the presence of an inexpensive copper catalyst (CuI; no ligand coadditive) and a readily available light source (UVC compact fluorescent light bulb), a wide array of alkyl halides undergo cyanation in good yield. Our initial mechanistic studies are consistent with the hypothesis that an excited state of [Cu(CN)2](-) may play a role, via single electron transfer, in this process. This investigation provides a rare example of a transition metal-catalyzed cyanation of an alkyl halide, as well as the first illustrations of photoinduced, copper-catalyzed alkylation with either a carbon nucleophile or a secondary alkyl chloride.

  4. Nano Copper Oxide-Modified Carbon Cloth as Cathode for a Two-Chamber Microbial Fuel Cell

    Science.gov (United States)

    Dong, Feng; Zhang, Peng; Li, Kexun; Liu, Xianhua; Zhang, Pingping

    2016-01-01

    In this work, Cu2O nanoparticles were deposited on a carbon cloth cathode using a facile electrochemical method. The morphology of the modified cathode, which was characterized by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) tests, showed that the porosity and specific surface area of the cathode improved with longer deposition times. X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) results showed that cupric oxide and cuprous oxide coexisted on the carbon cloth, which improved the electrochemical activity of cathode. The cathode with a deposition time of 100 s showed the best performance, with a power density twice that of bare carbon cloth. Linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) results revealed that moderate deposition of nano copper oxide on carbon cloth could dramatically reduce the charge transfer resistance, which contributed to the enhanced electrochemical performance. The mediation mechanism of copper oxide nanocatalyst was illustrated by the fact that the recycled conversion between cupric oxide and cuprous oxide accelerated the electron transfer efficiency on the cathode.

  5. Nano Copper Oxide-Modified Carbon Cloth as Cathode for a Two-Chamber Microbial Fuel Cell

    Directory of Open Access Journals (Sweden)

    Feng Dong

    2016-12-01

    Full Text Available In this work, Cu2O nanoparticles were deposited on a carbon cloth cathode using a facile electrochemical method. The morphology of the modified cathode, which was characterized by scanning electron microscopy (SEM and Brunauer-Emmett-Teller (BET tests, showed that the porosity and specific surface area of the cathode improved with longer deposition times. X-ray photoelectron spectroscopy (XPS and cyclic voltammetry (CV results showed that cupric oxide and cuprous oxide coexisted on the carbon cloth, which improved the electrochemical activity of cathode. The cathode with a deposition time of 100 s showed the best performance, with a power density twice that of bare carbon cloth. Linear sweep voltammetry (LSV and electrochemical impedance spectroscopy (EIS results revealed that moderate deposition of nano copper oxide on carbon cloth could dramatically reduce the charge transfer resistance, which contributed to the enhanced electrochemical performance. The mediation mechanism of copper oxide nanocatalyst was illustrated by the fact that the recycled conversion between cupric oxide and cuprous oxide accelerated the electron transfer efficiency on the cathode.

  6. Treatment of Copper Contaminated Municipal Wastewater by Using UASB Reactor and Sand-Chemically Carbonized Rubber Wood Sawdust Column.

    Science.gov (United States)

    Biswas, Swarup; Mishra, Umesh

    2016-01-01

    The performance of a laboratory scale upflow anaerobic sludge blanket (UASB) reactor and its posttreatment unit of sand-chemically carbonized rubber wood sawdust (CCRWSD) column system for the treatment of a metal contaminated municipal wastewater was investigated. Copper ion contaminated municipal wastewater was introduced to a laboratory scale UASB reactor and the effluent from UASB reactor was then followed by treatment with sand-CCRWSD column system. The laboratory scale UASB reactor and column system were observed for a period of 121 days. After the posttreatment column the average removal of monitoring parameters such as copper ion concentration (91.37%), biochemical oxygen demand (BODT) (93.98%), chemical oxygen demand (COD) (95.59%), total suspended solid (TSS) (95.98%), ammonia (80.68%), nitrite (79.71%), nitrate (71.16%), phosphorous (44.77%), total coliform (TC) (99.9%), and fecal coliform (FC) (99.9%) was measured. The characterization of the chemically carbonized rubber wood sawdust was done by scanning electron microscope (SEM), X-ray fluorescence spectrum (XRF), and Fourier transforms infrared spectroscopy (FTIR). Overall the system was found to be an efficient and economical process for the treatment of copper contaminated municipal wastewater.

  7. Synthesis of copper particles covered with cobalt-catalyzed carbon nanofibers and their application to air-curable conductive paste

    Science.gov (United States)

    Ohnishi, Shigekatsu; Nakasuga, Akira; Nakagawa, Kiyoharu

    2017-07-01

    Sea urchin-shaped hybrid copper powder (HCuP), which is characterized by copper alloy powder particles covered with vertically aligned Co-catalyzed carbon nanofibers (CNFs), was successfully synthesized to improve the oxidation resistance of copper paste. Fine spherical CuCo alloy particles with nominal composition of Cu/Co = 99/1 w/w were fabricated by atomization. Cobalt nanoprecipitates (CoNPs) used as the catalyst for carbon fiber growth were arranged on the surface of an alloy particle by heat treatment. CNFs were grown from the CoNPs on the alloy particle via thermal chemical vapor deposition (CVD). The conductive paste was prepared by milling using HCuP with resin and oleic acid. HCuP paste was screen-printed on a glass or plastic substrate and showed a resistivity as low as 1.2 × 10-4 Ω·cm after curing at 150 °C for 30 min in air (21% oxygen). These results indicate that the use of HCuP is a promising technology for printable electronics in a sustainable society.

  8. Controlled Synthesis of Carbon-Encapsulated Copper Nanostructures by Using Smectite Clays as Nanotemplates

    NARCIS (Netherlands)

    Tsoufis, Theodoros; Colomer, Jean-Francois; Maccallini, Enrico; Jankovic, Lubos; Rudolf, Petra; Gournis, Dimitrios; Jankovič, Lubos

    2012-01-01

    Rhomboidal and spherical metallic-copper nanostructures were encapsulated within well-formed graphitic shells by using a simple chemical method that involved the catalytic decomposition of acetylene over a copper catalyst that was supported on different smectite clays surfaces by ion-exchange. These

  9. How copper catalyzes the electroreduction of carbon dioxide into hydrocarbon fuels

    DEFF Research Database (Denmark)

    Peterson, Andrew; Abild-Pedersen, Frank; Studt, Felix

    2010-01-01

    Density functional theory calculations explain copper's unique ability to convert CO2 into hydrocarbons, which may open up (photo-)electrochemical routes to fuels.......Density functional theory calculations explain copper's unique ability to convert CO2 into hydrocarbons, which may open up (photo-)electrochemical routes to fuels....

  10. Controlled Synthesis of Carbon-Encapsulated Copper Nanostructures by Using Smectite Clays as Nanotemplates

    NARCIS (Netherlands)

    Tsoufis, Theodoros; Colomer, Jean-Francois; Maccallini, Enrico; Jankovic, Lubos; Rudolf, Petra; Gournis, Dimitrios; Jankovič, Lubos

    2012-01-01

    Rhomboidal and spherical metallic-copper nanostructures were encapsulated within well-formed graphitic shells by using a simple chemical method that involved the catalytic decomposition of acetylene over a copper catalyst that was supported on different smectite clays surfaces by ion-exchange. These

  11. Interfacial Cu+ promoted surface reactivity: Carbon monoxide oxidation reaction over polycrystalline copper-titania catalysts

    Science.gov (United States)

    Senanayake, Sanjaya D.; Pappoe, Naa Adokaley; Nguyen-Phan, Thuy-Duong; Luo, Si; Li, Yuanyuan; Xu, Wenqian; Liu, Zongyuan; Mudiyanselage, Kumudu; Johnston-Peck, Aaron C.; Frenkel, Anatoly I.; Heckler, Ilana; Stacchiola, Dario; Rodriguez, José A.

    2016-10-01

    We have studied the catalytic carbon monoxide (CO) oxidation (CO + 0.5O2 → CO2) reaction using a powder catalyst composed of both copper (5 wt.% loading) and titania (CuOx-TiO2). Our study was focused on revealing the role of Cu, and the interaction between Cu and TiO2, by systematic comparison between two nanocatalysts, CuOx-TiO2 and pure CuOx. We interrogated these catalysts under in situ conditions using X-ray diffraction (XRD), X-ray absorption fine structure (XAFS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to probe the structure and electronic properties of the catalyst at all stages of the reaction and simultaneously probe the surface states or intermediates of this reaction. With the aid of several ex situ characterization techniques including transmission electron microscopy (TEM), the local catalyst morphology and structure were also studied. Our results show that a CuOx-TiO2 system is more active than bulk CuOx for the CO oxidation reaction due to its lower onset temperature and better stability at higher temperatures. Our results also suggest that surface Cu+ species observed in the CuOx-TiO2 interface are likely to be a key player in the CO oxidation mechanism, while implicating that the stabilization of this species is probably associated with the oxide-oxide interface. Both in situ DRIFTS and XAFS measurements reveal that there is likely to be a Cu(Ti)-O mixed oxide at this interface. We discuss the nature of this Cu(Ti)-O interface and interpret its role on the CO oxidation reaction.

  12. Study of the damaging mechanisms of a copper / carbon - carbon composite under thermomechanical loading; Etude des mecanismes d'endommagement d'un assemblage cuivre / composite carbone - carbone sous chargement thermomecanique

    Energy Technology Data Exchange (ETDEWEB)

    Moncel, L

    1999-06-18

    The purpose of this work is to understand and to identify the damaging mechanisms of Carbon-Carbon composite bonded to copper under thermomechanical loading. The study of the composite allowed the development of non-linear models. These ones have been introduced in the finite elements analysis code named CASTEM2000. They have been validated according to a correlation between simulation and mechanical tests on multi-material samples. These tests have also permitted us to better understand the behaviour of the bonding between composite and copper (damaging and fracture modes for different temperatures) under shear and tensile loadings. The damaging mechanisms of the bond under thermomechanical loading have been studied and identified according to microscopic observations on mock-ups which have sustained thermal cycling tests: some cracks appear in the composite, near the bond between the composite and the copper. The correlation between numerical and experimental results have been improved because of the reliability of the composite modelization, the use of residual stresses and the results of the bond mechanical characterization. (author)

  13. Study of the damaging mechanisms of a carbon - carbon composite bonded to copper under thermomechanical loading; Etude des mecanismes d'endommagement d'un assemblage cuivre / composite carbone - carbone sous chargement thermomecanique

    Energy Technology Data Exchange (ETDEWEB)

    Moncel, L

    1999-06-15

    The purpose of this work is to understand and to identify the damaging mechanisms of Carbon-Carbon composite bonded to copper under thermomechanical loading. The study of the composite allowed the development of non-linear models. These ones have been introduced in the finite elements analysis code named CASTEM 2000. They have been validated according to a correlation between simulation and mechanical tests on multi-material samples. These tests have also permitted us to better understand the behaviour of the bonding between composite and copper (damaging and fracture modes for different temperatures) under shear and tensile loadings. The damaging mechanisms of the bond under thermomechanical loading have been studied and identified according to microscopic observations on mock-ups which have sustained thermal cycling tests: some cracks appear in the composite, near the bond between the composite and the copper. The correlation between numerical and experimental results have been improved because of the reliability of the composite modelization, the use of residual stresses and the results of the bond mechanical characterisation. (author)

  14. Effect of carbon coating on the physico-chemical properties and toxicity of copper and nickel nanoparticles.

    Science.gov (United States)

    Minocha, Shalini; Mumper, Russell J

    2012-11-05

    The primary aim of these interdisciplinary studies is to investigate the effect of surface carbon coating on the physico-chemical properties and toxicity of carbon-coated and noncoated copper and nickel nanoparticles (C-Cu, Cu, C-Ni, Ni NPs) in A549 alveolar epithelial cells. Compared to Cu NPs, C-Cu NPs exhibit protection against surface oxidation, tenfold higher cellular uptake, and fourfold lower release of soluble Cu. The toxicity of C-Cu NPs and Cu NPs is associated with pronounced damage to mitochondrial function and plasma membrane integrity, respectively. Compared to Cu and C-Cu NPs, Ni and C-Ni NPs are less toxic. These studies demonstrate that correlations can be drawn between physico-chemical properties and resultant toxicity of NPs as a function of surface carbon coating.

  15. Laser synthesis of a copper-single-walled carbon nanotube nanocomposite via molecular-level mixing and non-equilibrium solidification

    Science.gov (United States)

    Tu, Jay F.; Rajule, Nilesh; Molian, Pal; Liu, Yi

    2016-12-01

    A copper-single-walled carbon nanotube (Cu-SWCNT) metal nanocomposite could be an ideal material if it can substantially improve the strength of copper while preserving the metal’s excellent thermal and electrical properties. However, synthesis of such a nanocomposite is highly challenging, because copper and SWCNTs do not form intermetallic compounds and are insoluble; as a result, there are serious issues regarding wettability and fine dispersion of SWCNTs within the copper matrix. In this paper we present a novel wet process, called the laser surface implantation process (LSI), to synthesize Cu-SWCNT nanocomposites by mixing SWCNTs into molten copper. The LSI process includes drilling several microholes on a copper substrate, filling the microholes with SWCNTs suspended in solution, and melting the copper substrate to create a micro-well of molten copper. The molten copper advances radially outward to engulf the microholes with pre-deposited SWCNTs to form the Cu-SWCNT implant upon solidification. Rapid and non-equilibrium solidification is achieved due to copper’s excellent heat conductivity, so that SWCNTs are locked in position within the copper matrix without agglomerating into large clusters. This wet process is very different from the typical dry processes used in powder metallurgy. Very high hardness improvement, up to 527% over pure copper, was achieved, confirmed by micro-indentation tests, with only a 0.23% SWCNT volume fraction. The nanostructure of the nanocomposite was characterized by TEM imaging, energy-dispersive x-ray spectroscopy mapping and spectroscopy measurements. The SWCNTs were found to be finely dispersed within the copper matrix with cluster sizes in the range of nanometers, achieving the goal of molecular-level mixing.

  16. Obtenção de filmes espessos de seleneto de cobre sobre carbono vítreo, ouro, titânio e cobre Obtaining copper selenide thick films on vitreous carbon, gold, titanium and copper

    Directory of Open Access Journals (Sweden)

    Adriano César Rabelo

    2007-04-01

    Full Text Available Copper selenide (berzelianite films were prepared on the title substrates using the chemical bath deposition technique (CBD. Film composition was determined by energy dispersion of x-rays. The kinetics of film growth is parabolic and film adherence limits the film thickness. On titanium, copper selenide forms islands that do not completely cover the surface, unless the substrate is prepared with a tin oxide layer; film composition also depends on the titanium oxide layer. On vitreous carbon, CBD and mechanical immobilization techniques lead to films with similar resistances for the electron transfer across the film/substrate interface. On gold, composition studies revealed that film composition is always the same if the pH is in the range from 8 to 12, in contrast to films prepared by an ion-ion combination route. On copper, a new procedure for obtaining copper selenide films as thick as 5 µm has been developed.

  17. Electrocrystallizations of copper on glassy carbon in CuCl2 silica sol and aqueous solutions

    Institute of Scientific and Technical Information of China (English)

    Yan Yan Feng; Min Gu; Yun Gui Du

    2012-01-01

    Electrocrystallizations of copper from both CuCl2 silica sol and aqueous solutions were studied by the chronoamperometry technique.It was found that current density contributions of the double-layer charging (iDL) in current-time transients (CTTs) from both of the solutions were large.An adsorption-nucleation based model was proposed to analyze quantitatively the CTTs,by which copper electrocrystallization mechanism was characterized as progressive nucleation with 3D growth (3DP) under diffusion control.The diffusion coefficient of copper ions and the AN∞ products in aqueous solutions were larger than that in silica sols,which indicated that copper nucleation was inhibited in sol solution.The large iDL may be resulted from the adsorption of chloride ions on the electrode surface.

  18. Purity-enhanced bulk synthesis of thin single-wall carbon nanotubes using iron-copper catalysts

    Science.gov (United States)

    Lim, H. E.; Miyata, Y.; Nakayama, T.; Chen, S.; Kitaura, R.; Shinohara, H.

    2011-09-01

    We report high purity and high yield synthesis of single-wall carbon nanotubes (SWCNTs) of narrow diameter from iron-copper bimetal catalysts. The SWCNTs with diameter of 0.8-1.2 nm are synthesized using the zeolite-supported alcohol chemical vapour deposition method. Single metal and bimetal catalysts are systematically investigated to achieve both the enhancement of SWCNT yield and the suppression of the undesired formation of graphitic impurities. The relative yield and purity of SWCNTs are quantified using optical absorption spectroscopy with an ultracentrifuge-based purification technique. For the single metal catalyst, iron shows the highest catalytic activity compared with the other metals such as cobalt, nickel, molybdenum, copper, and platinum. It has been found that the addition of copper to iron results in the suppression of carbonaceous impurity formation without decreasing the SWCNT yield. The purity-enhanced SWCNT shows fairly low sheet resistance due to the improvement of inter-nanotube contacts. This scalable design of SWCNT synthesis with enhanced purity is therefore a promising tool for shaping future high performance devices.

  19. Emprego do carvão ativado para remoção de cobre em cachaça Using activated carbon to remove copper from sugar cane spirit

    Directory of Open Access Journals (Sweden)

    Annete de J. Boari Lima

    2006-04-01

    Full Text Available Copper content is of great concern among sugarcane-spirit producers. It is released from copper-made distillers, during the distillation process. Activated carbon has been used to remove copper. However, depending on the amount of carbon and the duration of reaction, it can also remove higher alcohols and esters, which are important in the final product. A sugarcane spirit with 9 mg L-1 of copper was shaken with 2 to 26 g L-1 of activated carbon, during 10 to 1440 minutes. Then, copper and organic compounds were measured. At least 12 g L-1 of carbon and 60 min shaking time were necessary to decrease copper bellow 5 mg L-1. However, other components of the product were also affected.

  20. Research on copper removal from high copper content gold-loaded carbon and its application%高铜载金炭脱铜技术研究及应用

    Institute of Scientific and Technical Information of China (English)

    陈淑萍; 王春; 刘亚建; 赖桂华; 衷水平; 伍赠玲; 王世辉; 简伟峰

    2015-01-01

    To deal with the adverse effect high copper content gold-loaded carbon imposes on gold production in the ore-dressing plant of Zijinshan Gold Copper Mine ,a process of copper removal by cyanidation and copper reduction in the terminal stage by heap leaching is carried out to perform the experimental research on copper removal and pro -duction practice .The results show that bench scale copper removal tests by cyanidation can reach a copper removal rate of more than 91 %;the practice of copper removal by cyanidation and copper reduction in the terminal stage by heap leaching is able to cut production cost once the copper removal rate reaches 50%which is qualified for gold de-sorption .The copper grade in high copper content gold-loaded carbon decreases from more than 20 g/kg to less than 10 g/kg.The gold desorption rate of treated gold-loaded carbon under high temperature and pressure reaches more than 97 .5%and the gold grade in the carbon after gold deprivation decreases to lower than 0 .1 g/kg;the technique of copper reduction in the terminal stage by heap leaching solves the problem of copper deprived solution treatment . The process has the advantages of low cost ,less investment ,easy operation and vast sum of profits .%为解决紫金山金铜矿选矿厂产生的高铜载金炭对提金生产造成的不利影响,采用氰化脱铜-堆浸末期降铜工艺进行了除铜试验研究及生产实践。其结果表明:小型氰化脱铜试验铜脱除率可达9 l %以上;氰化脱铜-堆浸末期降铜工业生产实践中,为降低生产成本,脱铜率达50%以上即可,此时已满足解吸金的指标要求,其高铜载金炭铜品位由20 g/kg以上降到10 g/kg以下,脱铜载金炭高温高压解吸金的解吸率达到97.5%以上,脱金炭金品位基本降至0.1 g/kg以下;其堆浸末期降铜技术的应用,较好地解决了脱铜液难处理的问题。该工艺具有成本低、投资少、操作简单、效益显著等优点。

  1. Copper Nanoparticle/Multiwalled Carbon Nanotube Composite Films with High Electrical Conductivity and Fatigue Resistance Fabricated via Flash Light Sintering.

    Science.gov (United States)

    Hwang, Hyun-Jun; Joo, Sung-Jun; Kim, Hak-Sung

    2015-11-18

    In this work, multiwalled carbon nanotubes (MWNTs) were employed to improve the conductivity and fatigue resistance of flash light sintered copper nanoparticle (NP) ink films. The effect of CNT weight fraction on the flash light sintering and the fatigue characteristics of Cu NP/CNT composite films were investigated. The effect of carbon nanotube length was also studied with regard to enhancing the conductivity and fatigue resistance of flash light sintered Cu NP/CNT composite films. The flash light irradiation energy was optimized to obtain high conductivity Cu NP/CNT composite films. Cu NP/CNT composite films fabricated via optimized flash light irradiation had the lowest resistivity (7.86 μΩ·cm), which was only 4.6 times higher than that of bulk Cu films (1.68 μΩ·cm). It was also demonstrated that Cu NP/CNT composite films had better durability and environmental stability than those of Cu NPs only.

  2. Debris reduction for copper and diamond-like carbon thin films produced by magnetically guided pulsed laser deposition

    CERN Document Server

    Tsui, Y Y; Vick, D; Fedosejevs, R

    2002-01-01

    The effectiveness of debris reduction using magnetically guided pulsed laser deposition (MGPLD) is reported here. KrF laser pulses (248 nm) of 100 mJ energy were focused to intensities of 6x10 sup 9 W/cm sup 2 onto the surface of a copper or a carbon source target and a magnetic field of 0.3 T as used to steer the plasma around a curved arc of 0.5 m length to the deposition substrate. Debris counts were compared for films produced by the MGPLD and conventional PLD (nonguided) techniques. A significant reduction in particulates of size greater than 0.1 mu m was achieved using MGPLD. For the copper films, particulate count was reduced from 150 000 particles/cm sup 2 /nm to 50 particulates/cm sup 2 /nm and for diamond-like carbon thin films particulate count was reduced from 25 000 particles/cm sup 2 /nm to 1200 particles/cm sup 2 /nm.

  3. Transitions in Wear and Friction of Carbon Fiber Reinforced Copper Matrix Composite Sliding Against AISI-1045 Steel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The friction and wear properties of carbon fiber reinforced copper matrix composite in dry sliding against AISI-1045 steel was evaluated by a block-on-ring test machine. It was shown that the low frictional factor and wear rate of the composite block could be maintained when pressure or velocity was below a certain value. But when the pressure or velocity exceeded the critical value, the friction factor and wear rate tended to increase rapidly with pressure and sliding velocity. The morphologies, elemental compositions, and surface profile of worn composite surfaces at different wear stages were analyzed by means of scanning electron microscopy, energy dispersive spectrometry, and profile-meter. It was found that low values of friction and wear were due to a thin solid film forming on the surface of the composite block which includes carbon and copper at a mild wear stage. The film could impede adhesion and provide some degree of self-lubrication. When the film included more metal elements and were damaged, severe wear happened, and the wear rate increased sharply. As a result, a transition diagram in friction and wear was constructed, which provided pressure and velocity conditions of change from mild wear and low friction to severe wear and high friction for the wear-resisting design.

  4. Controlled synthesis of carbon-encapsulated copper nanostructures by using smectite clays as nanotemplates.

    Science.gov (United States)

    Tsoufis, Theodoros; Colomer, Jean-François; Maccallini, Enrico; Jankovič, Lubos; Rudolf, Petra; Gournis, Dimitrios

    2012-07-23

    Rhomboidal and spherical metallic-copper nanostructures were encapsulated within well-formed graphitic shells by using a simple chemical method that involved the catalytic decomposition of acetylene over a copper catalyst that was supported on different smectite clays surfaces by ion-exchange. These metallic-copper nanostructures could be separated from the inorganic support and remained stable for months. The choice of the clay support influenced both the shape and the size of the synthesized Cu nanostructures. The synthesized materials and the supported catalysts from which they were produced were studied in detail by TEM and SEM, powder X-ray diffraction, thermal analysis, as well as by Raman and X-ray photoelectron spectroscopy. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. A Thermally Conductive Composite with a Silica Gel Matrix and Carbon-Encapsulated Copper Nanoparticles as Filler

    Science.gov (United States)

    Lin, Jin; Zhang, Haiyan; Hong, Haoqun; Liu, Hui; Zhang, Xiubin

    2014-07-01

    Core-shell-structured nanocapsules with a copper core encapsulated in a carbon shell (Cu-C) were synthesized by a direct-current arc-discharge method. Morphological and microstructural characterization showed that the Cu-C consisted of a nanosized Cu core and carbon shell, with the carbon shells containing 6 to 15 ordered graphitic layers and amorphous carbon that effectively shield the metallic Cu core from oxidation. A thermally conductive composite was successfully fabricated using a silica gel matrix incorporated with Cu-C filler. The Cu-C nanoparticles were homogeneously dispersed in the silica gel. The effects of Cu-C on the thermal conductivity, electrical resistivity, and coefficient of thermal expansion (CTE) of the composite were investigated. For composites with 6.16 vol.%, 11.04 vol.%, 16.70 vol.%, and 23.34 vol.% Cu-C content, the thermal conductivity at 50°C was 0.32 W/(m K) to 0.77 W/(m K), the electrical resistivity was 1.98 × 109, 3.48 × 107, 302, and 1 Ω m, respectively, while the CTE at 200°C was 3.79 × 10-4 K-1 to 3.44 × 10-4 K-1. The results reveal that the ordered graphitic shells in the Cu-C increased both the thermal and electrical conduction, but decreased the CTE by preventing the Cu cores from expanding.

  6. Mechanochemical reactions on copper-based compounds

    NARCIS (Netherlands)

    Castricum, H.L.; Bakker, H.; Poels, E.K.

    1999-01-01

    Mechanochemical reactions of copper and copper oxides with oxygen and carbon dioxide are discussed, as well as decomposition and reduction of copper compounds by mechanical milling under high-vacuum conditions.

  7. Copper allergy from dental copper amalgam?

    Science.gov (United States)

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

    2002-05-06

    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.

  8. Quenching and partitioning response of carbon-manganese-silicon sheet steels containing nickel, molybdenum, aluminum and copper additions

    Science.gov (United States)

    Kahkonen, Joonas

    In order to produce passenger vehicles with improved fuel economy and increased passenger safety, car manufacturers are in need of steels with enhanced strength levels and good formability. Recently, promising combinations of strength and ductility have been reported for several, so-called third generation advanced high-strength steels (AHSS) and quenching and partitioning (Q&P) steels are increasingly being recognized as a promising third generation AHSS candidate. Early Q research used conventional TRIP steel chemistries and richer alloying strategies have been explored in more recent studies. However, systematic investigations of the effects of alloying elements on tensile properties and retained austenite fractions of Q&P steels are sparse. The objective of the present research was to investigate the alloying effects of carbon, manganese, molybdenum, aluminum, copper and nickel on tensile properties and microstructural evolution of Q&P heat treated sheet steels. Seven alloys were investigated with 0.3C-1.5Mn-1.5Si (wt pct) and 0.4C-1.5Mn-1.5Si alloys used to study carbon effects, a 0.3C-5Mn-1.6Si alloy to study manganese effects, 0.3C-3Mn-1.5Si-0.25Mo and 0.3C-3Mn-1.5Si-0.25Mo-0.85Al alloys to study molybdenum and aluminum effects and 0.2C-1.5Mn-1.3Si-1.5Cu and 0.2C-1.5Mn-1.3Si-1.5Cu-1.5Ni alloys to study copper and nickel effects. Increasing alloy carbon content was observed to mainly increase the ultimate tensile strength (UTS) up to 1865 MPa without significantly affecting total elongation (TE) levels. Increasing alloy carbon content also increased the resulting retained austenite (RA) fractions up to 22 vol pct. Measured maximum RA fractions were significantly lower than the predicted maximum RA levels in the 0.3C-1.5Mn-1.5Si and 0.4C-1.5Mn-1.5Si alloys, likely resulting from transition carbide formation. Increasing alloy manganese content increased UTS, TE and RA levels, and decreased yield strength (YS) and austenite carbon content (Cgamma) levels

  9. A comprehensive theoretical study on the coupling reaction mechanism of propylene oxide with carbon dioxide catalyzed by copper(I) cyanomethyl.

    Science.gov (United States)

    Guo, Cai-Hong; Wu, Hai-Shun; Zhang, Xian-Ming; Song, Jiang-Yu; Zhang, Xiang

    2009-06-18

    The mechanistic details of the coupling reaction of propylene oxide with carbon dioxide catalyzed by copper(I) cyanomethyl to yield cyclic carbonate were elucidated by density functional theory (DFT) calculations at the B3LYP/6-311G** level. Our results reveal that the overall reaction is stepwise and considered to include two processes. In process 1, CO(2) insertion into the Cu(I)-C bond of copper(I) cyanomethyl affords activated carbon dioxide carriers. In process 2, O-coordination of propylene oxide molecule to the electrophilic copper center of carriers occurs. Herein, three possible pathways were investigated, and the calculated reaction free energy profiles were compared. It was found that carrier 8 reacting with propylene oxide is more favored than the other two carriers (6 and 7) both kinetically and thermodynamically. Several factors, such as the composition of catalyst, the coordinate environment of copper, and the symmetry of frontier molecular orbitals, affected the reaction mechanisms, and the outcomes were identified. The overall reaction is exothermic. In addition, natural bond orbital (NBO) analysis has been performed to study the effects of charge transfer and understand the nature of different interactions between atoms and groups. The present theoretical study explains satisfactorily the early reported experimental observations well and provides a clear profile for the cycloaddition of carbon dioxide with propylene oxide promoted by NCCH(2)Cu.

  10. Self-assembly of a chiral carbonate- and cytidine-containing dodecanuclear copper(II) complex: a multiarm-supplied globular capsule.

    Science.gov (United States)

    Armentano, Donatella; Marino, Nadia; Mastropietro, Teresa F; Martínez-Lillo, José; Cano, Joan; Julve, Miguel; Lloret, Francesc; De Munno, Giovanni

    2008-11-17

    A dodecanuclear copper(II) globular-shaped structure has been obtained with the cytidine nucleoside and the templating carbonate anion. It shows receptor properties through anion-cation and multiple anion-pi interactions toward ClO 4 (-) as well as an overall antiferromagnetic coupling.

  11. Copper(I)-catalyzed aryl bromides to form intermolecular and intramolecular carbon-oxygen bonds.

    Science.gov (United States)

    Niu, Jiajia; Guo, Pengran; Kang, Juntao; Li, Zhigang; Xu, Jingwei; Hu, Shaojing

    2009-07-17

    A highly efficient Cu-catalyzed C-O bond-forming reaction of alcohol and aryl bromides has been developed. This transformation was realized through the use of copper(I) iodide as a catalyst, 8-hydroxyquinoline as a ligand, and K(3)PO(4) as a base. A variety of functionalized substrates were found to react under these reaction conditions to provide products in good to excellent yields.

  12. Antifouling effect of two saturated copper coatings applied on carbon steel structures

    Directory of Open Access Journals (Sweden)

    Guiamet, P. S.

    2008-10-01

    Full Text Available Biofouling is the colonization of man-made substrata by sessile organisms. The aim of this paper is to evaluate the performance of two antifouling saturated copper coating. Bioassays were carried out at a harbor in Argentine (38°02’S- 57°32’W. During six months, one series of pipes and panels were removed monthly to estimate the recruitment of macro and microfouling species and immediately replaced by clean ones. Another series was removed from the beginning of exposure to monitor the development of the established community (accumulative pipes and panels along six months. Data obtained from control (without a saturated copper coating and saturated-copper coated pipes and panels were compared in order to estimate performance of the coating. One of two saturated copper coating demonstrated a good effect antifouling.

    El biofouling es la colonización por organismos sésiles en sistemas de sustratos hechos por el hombre. El objetivo fue evaluar el efecto antifouling de dos cubiertas saturadas de cobre. Los estudios se llevaron a cabo en un puerto de la Argentina (38°02’S-57°32’W. Durante seis meses, una serie de caños y paneles fueron removidos mensualmente para estimar el reclutamiento de las especies del macro y microfouling, y fueron sustituidos inmediatamente por caños y paneles limpios. La otra serie de caños y paneles fueron removidas desde el inicio de la exposición en forma acumulativa durante los seis meses, para seguir el desarrollo de la comunidad. Los datos obtenidos de los controles sin cubierta y de los caños y paneles con las cubiertas saturadas de cobre fueron comparados para estimar el comportamiento antifouling de las mismas. Una de las dos cubiertas saturadas de cobre demostró un buen efecto antifouling.

  13. Enhanced interfacial strength of carbon nanotube/copper nanocomposites via Ni-coating: Molecular-dynamics insights

    Science.gov (United States)

    Duan, Ke; Li, Li; Hu, Yujin; Wang, Xuelin

    2017-04-01

    The molecular bridging between carbon nanotube (CNT) within the meta matrix is hopeful for enhancing nanocomposite's mechanical performance. One of the main problems for nanocomposites is the inadequate bonding between nonstructural reinforcement and meta matrix. Ni-coating on CNT is an effective method to overcome the drawback of the inadequate strength, but the enhancing mechanism has not well interpreted yet. In this paper, the enhancing mechanism will be interpreted from the molecular-dynamics insights. The pullout process of CNT and Ni-coated CNT against copper matrix is investigated. The effects of geometric parameters, including CNT length and diameter, are taken into considerations and discussed. Results show that the interfacial strength is significantly improved after the Ni-coated CNT, which shows a good agreement with the experimental results available in the open literature. Besides, the sliding mechanism of Ni-coated CNTs against copper matrix is much more like a kind of friction sliding and directly related to the embedded zone. However, the pullout force of the CNT without Ni-coating is nearly proportional to its diameter, but independent of embedded length.

  14. Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

    Science.gov (United States)

    Hu, Xiang; Zhang, Hua; Sun, Zhirong

    2017-01-01

    In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g-1 (298 K), 196.1 mg g-1 (303 K) and 185.2 mg g-1 (308 K). It was much higher than that of AC-Fe and AC-Al. And the process was controlled by both film diffusion and intra particle mass transport. The results also showed that, the Freundlich and Temkin isotherm fit the adsorption well.

  15. Electrochemical determination of copper ions in spirit drinks using carbon paste electrode modified with biochar.

    Science.gov (United States)

    Oliveira, Paulo Roberto; Lamy-Mendes, Alyne C; Rezende, Edivaltrys Inayve Pissinati; Mangrich, Antonio Sálvio; Marcolino, Luiz Humberto; Bergamini, Márcio F

    2015-03-15

    This work describes for first time the use of biochar as electrode modifier in combination with differential pulse adsorptive stripping voltammetric (DPAdSV) techniques for preconcentration and determination of copper (II) ions in spirit drinks samples (Cachaça, Vodka, Gin and Tequila). Using the best set of the experimental conditions a linear response for copper ions in the concentration range of 1.5 × 10(-6) to 3.1 × 10(-5) mol L(-1) with a Limit of Detection (LOD) of 4.0 × 10(-7) mol L(-1). The repeatability of the proposed sensor using the same electrode surface was measured as 3.6% and 6.6% using different electrodes. The effect of foreign species on the voltammetric response was also evaluated. Determination of copper ions content in different samples of spirit drinks samples was also realized adopting inductively coupled plasma optical emission spectroscopy (ICP-OES) and the results achieved are in agreement at a 95% of confidence level.

  16. Structural characteristics of copper/hydrogenated amorphous carbon composite films prepared by microwave plasma-assisted deposition processes from methane-argon and acetylene-argon gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Thiery, F.; Pauleau, Y.; Grob, J.J.; Babonneau, D

    2004-11-01

    Copper/hydrogenated amorphous carbon (Cu/a-C:H) composite films have been deposited on silicon substrates by a hybrid technique combining microwave plasma-assisted chemical vapor deposition and sputter-deposition from methane-argon and acetylene-argon gas mixtures. The major objective of this work was to investigate the effect of the carbon gas precursor on the structural characteristics of Cu/a-C:H composite films deposited at ambient temperature. The major characteristics of CH{sub 4}-argon and C{sub 2}H{sub 2}-argon plasmas were analyzed by Langmuir probe measurements. The composition of films was determined by Rutherford backscattering spectroscopy, energy recoil detection analyses and nuclear reaction analyses. The carbon content in the films was observed to vary in the range 20-77 at.% and 7.5-99 at.% as the CH{sub 4} and C{sub 2}H{sub 2} concentrations in the gas phase increased from 10 to 100%, respectively. The atom number ratio H/C in the films was scattered approximately 0.4 whatever the carbon gas precursor used. The crystallographic structure and the size of copper crystallites incorporated in the a-C were determined by X-ray diffraction techniques. The copper crystallite size decreased from 20 nm in pure copper films to less than 5 nm in Cu/a-C:H films containing more than 40 at.% of carbon. Grazing incidence small angle X-ray scattering measurements were performed to investigate the size distribution and distance of copper crystallites as functions of the deposition parameters. The structural characteristics of copper crystallites were dependent on the hydrocarbon gas precursor used. The crystallite size and the width of the size distribution were homogeneous in films deposited from CH{sub 4}. Copper crystallites with an anisotropic shape were found in films deposited from C{sub 2}H{sub 2}. The major radicals formed in the plasma and condensed on the surface of growing films, namely CH and C{sub 2}H radicals for films produced from CH{sub 4} and C

  17. Non-electrolytic synthesis of copper oxide/carbon nanocomposite by surface plasma in super-dehydrated ethanol

    Science.gov (United States)

    Kozak, Dmytro S.; Sergiienko, Ruslan A.; Shibata, Etsuro; Iizuka, Atsushi; Nakamura, Takashi

    2016-02-01

    Electrolytic processes are widely used to synthesize different nanomaterials and it does not depend on what kind of the method has been applied (wet-chemistry, sonochemistry, plasma chemistry, electrolysis and so on). Generally, the reactions in the electrolyte are considered to be reduction/oxidation (REDOX) reactions between chemical reagents or the deposition of matter on the electrodes, in line with Faraday’s law. Due to the presence of electroconductive additives in any electrolyte, the polarization effect of polar molecules conducting an electrical current disappears, when external high-strength electric field is induced. Because initially of the charge transfer always belongs of electroconductive additive and it does not depend on applied voltage. The polarization of ethanol molecules has been applied to conduct an electric current by surface plasma interaction for the synthesis of a copper oxide/carbon nanocomposite material.

  18. Oxygen and hydrogen peroxide reduction catalyses in neutral aqueous media using copper ion loaded glassy carbon electrode electrolyzed in ammonium carbamate solution

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Hiroaki; Yamazaki, Haruhito [Department of Materials Science and Engineering, Graduate School of Engineering, Saitama Institute of Technology, 1690 Fusaiji Fukaya, Saitama 369-0293 (Japan); Wang, Xiuyun [School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, Liaoning, 114051 (China); Uchiyama, Shunichi [Department of Materials Science and Engineering, Graduate School of Engineering, Saitama Institute of Technology, 1690 Fusaiji Fukaya, Saitama 369-0293 (Japan)], E-mail: uchiyama@sit.ac.jp

    2009-01-30

    An aminated glassy carbon electrode (AGCE) can be obtained by the electrode oxidation of glassy carbon electrode in ammonium carbamate solution. In the cyclic voltammetric experiments, the electrode reduction of the dissolved oxygen began from -0.15 V vs. Ag/AgCl in neutral aqueous media when the aminated glassy carbon electrode was used as a working electrode although it began from -0.40 V vs. Ag/AgCl when a polished GCE was used. The nitrogen containing groups introduced by the electrode oxidation of carbamic acid must be related with the acceleration of the electron transfer rate of oxygen. Moreover, the new reduction wave of the dissolved oxygen appeared at +0.15 V vs. Ag/AgCl when copper (II) ion was coordinated to AGCE surface. This reduction potential of oxygen coincided with that of copper (II) ion and this fact suggests that the coordinated copper ion to the aminated carbon surface works as a redox mediator of oxygen. The reduction product of oxygen was monitored by rotating platinum ring - aminated glassy carbon disk electrode, and it was found that most of oxygen was reduced to water in a potential range negative than -0.4 V vs. Ag/AgCl. By using AGCE, it was recognized that the catalytic reduction of hydrogen peroxide was also taken place as well as oxygen reduction.

  19. Oxidative dissolution of copper and zinc metal in carbon dioxide with tert-butyl peracetate and a beta-diketone chelating agent.

    Science.gov (United States)

    Visintin, Pamela M; Bessel, Carol A; White, Peter S; Schauer, Cynthia K; DeSimone, Joseph M

    2005-01-24

    A series of beta-diketone ligands, R(1)COCH(2)COR(2) [tmhdH (R(1) = R(2) = C(CH(3))(3)); tfacH (R(1) = CF(3); R(2) = CH(3)); hfacH (R(1) = R(2) = CF(3))], in combination with tert-butyl peracetate (t-BuPA), have been investigated as etchant solutions for dissolution of copper metal into carbon dioxide solvent. Copper removal in CO(2) increases in the order tfacH chemical variables in the etching reaction. These t-BuPA/hfacH etchant solutions may find application in a CO(2)-based chemical mechanical planarization (CMP) process.

  20. Transport Measurements in the Mixed Ion-Electron Conductor Copper(x) Carbon-Disulfide

    Science.gov (United States)

    Kuo, Hung-Jen

    (sigma)(,i), (sigma)(,e), and the chemical diffusion coefficient, (')D, of highly-disordered Cu(,x)CS(,2) were investigated using a dc 4-lead technique employing Pt electrodes. The experiments were performed at various copper concentrations from x = 2.87 to 3.60 and various temperatures from 260 K to 350 K. The results were interpreted by Yokota's and ionic hopping diffusion theories. (sigma)(,i) and (sigma)(,e) are comparable at room temperature, 4.18 x 10('-3) (OMEGA)('-1)cm('-1) and 1.55 x 10('-3) (OMEGA)('-1)cm('-1) respectively at X = 3.60 and 300 K. Both (sigma)(,i) and (sigma)(,e) follow a simple Arrhenius form with activation energies (TURN)0.40 eV and (TURN)0.29 eV respectively. The exponential dependence of (sigma)(,i) on X is explained in terms of the activation entropy associated with the motion of ions. Electronic conduction is by hopping. Results show that it is reasonable to assume that all the copper ions are mobile. The mobility and the diffusivity of copper ions were found to be 0.71 x 10('-6) cm('2)V(' -1)sec('-1) and 1.83 x 10('-8) cm('2)/sec respectively at X = 3.6 and 300 K. The diffusivity is much less than the chemical diffusion coefficient evaluated from the diffusion time constant, (')D = 0.829 x 10('-5) cm('2)/sec at X = 3.60 and 300 K. This is because of a large enhancement factor W (TURN) 453, or a large (PAR-DIFF)m(,e)/(PAR-DIFF)N. The change in galvanic cell potential E with X, -(PAR-DIFF)E/(PAR -DIFF)X, calculated from the measurements of (sigma)(,i), (sigma)(,e), and (')D, is 14 Volt.

  1. Competition between Hydrogen Evolution and Carbon Dioxide Reduction on Copper Electrodes in Mildly Acidic Media.

    Science.gov (United States)

    Ooka, Hideshi; Figueiredo, Marta C; Koper, Marc T M

    2017-09-19

    Understanding the competition between hydrogen evolution and CO2 reduction is of fundamental importance to increase the faradaic efficiency for electrocatalytic CO2 reduction in aqueous electrolytes. Here, by using a copper rotating disc electrode, we find that the major hydrogen evolution pathway competing with CO2 reduction is water reduction, even in a relatively acidic electrolyte (pH 2.5). The mass-transport-limited reduction of protons takes place at potentials for which there is no significant competition with CO2 reduction. This selective inhibitory effect of CO2 on water reduction, as well as the difference in onset potential even after correction for local pH changes, highlights the importance of differentiating between water reduction and proton reduction pathways for hydrogen evolution. In-situ FTIR spectroscopy indicates that the adsorbed CO formed during CO2 reduction is the primary intermediate responsible for inhibiting the water reduction process, which may be one of the main mechanisms by which copper maintains a high faradaic efficiency for CO2 reduction in neutral media.

  2. Mass transfer study on the electrochemical removal of copper ions from synthetic effluents using reticulated vitreous carbon.

    Science.gov (United States)

    Britto-Costa, Pedro H; Ruotolo, Luís Augusto M

    2013-01-01

    Porous electrodes have been successfully used for metal electrodeposition from diluted aqueous solution due to their high porosity and specific surface area, which lead to high mass transfer rates. This work studies the mass transfer of copper electrodeposition on reticulated vitreous carbon in a flow reactor without membrane. The flow configuration, otherwise the filter-press electrochemical reactors, was designed in order to minimize the pressure drop. The mass transfer coefficient was determined by voltammetric and galvanostatic electrodeposition. In the voltammetric experiments a Luggin capillary was used to measure the current-potential curves and to determine the limiting current (and, consequently, the mass transfer coefficient). In the galvanostatic experiments the concentration-time curves were obtained and considering a limiting current kinetics model, the mass transfer coefficient (k(m)) was determined for different flow velocities. The results showed that both methods give similar values of k(m), thus the voltammetric method can be recommended because it is faster and simpler. Finally, the reactor performance was compared with others from literature, and it was observed that the proposed reactor design has high Sherwood numbers similar to other reactor configurations using membranes and reticulated vitreous carbon electrodes.

  3. Support- dependent evolution of oxidation state and nanoassembly formation of subnanometer copper clusters under carbon dioxide conversion conditions

    Science.gov (United States)

    Halder, Avik; Yang, Bing; Kolipaka, Karthika L.; Pellin, Michael; Seifert, Soenke; Vajda, Stefan; Materials Science Division Team

    Size- and support- dependence of the properties of copper clusters have been investigated during carbon dioxide conversion with hydrogen at high reactant concentrations and atmospheric pressure. The model catalyst systems were prepared by depositing size-selected Cun clusters (n = 3, 4, 12 and 20) on various amorphous metal oxide (Al2O3, ZnO, and ZrO2) , and carbon-based (UNCD = ultrananocrystaline diamond) supports. During the temperature ramp, the evolution of the chemical state and size of the particles were characterized by in situ grazing incidence X-ray absorption near edge structure (GIXANES), and grazing incidence small angle X-ray scattering (GISAXS) respectively. Under reaction conditions the initially oxidized Cu clusters reduced at various temperatures depending on cluster size and support. Clusters supported on ZnO and UNCD were found to be sinter-resistant under reactive gases at elevated temperatures and atmospheric pressures, whereas on ZrO2 support the clusters formed stable aggregates. Clusters on Al2O3 support demonstrated unique properties, where a formation of a nanostructure was observed during heating, which then disintegrated during the cool down. Under applied conditions, Cu4 clusters on Al2O3 were found to be the most efficient in methanol formation.

  4. Study of Silicon Nitrate and Tin Dioxide carbon nanotube composite as lithium-ion battery anode, gas sensor and the self-assembly of carbon nanotubes on copper substrates

    Science.gov (United States)

    Hernandez-Lugo, Dionne M.

    Carbon nanotubes since their discovery have been used for many applications. They are predicted to reinforce novel composite materials because of their structural perfection, excellent mechanical properties and low density. CNT can be made into nanowires of different materials or as part of a composite making them beneficial for the incorporation into electrochemical devices. Carbon nanotubes in this study were gown directly on a copper substrate employing hot filament chemical vapor deposition (HFCVD). Bamboo-like carbon nanotubes were made into electrodes reducing the use of inactive materials on the development of working electrodes for electrochemical application. This BCNT were tested as lithium-ion battery anodes assembled together with high capacity materials such as Silicon and Tin Oxide (4200mAh/g and 782 mAh/g). On this study BCNT served as a conductive matrix as well as buffer matrix for the volume expansion brought by cycling silicon and tin oxide. The composite structural properties enhance the surface-to-volume ratio of the electrode demonstrating a desirable electrochemical performance for a lithium-ion battery anode. As a gas sensor electrode CNT was assembled with tin-oxide directly on a copper substrate for the detection of ethanol, methanol, ammonia and H2S. CNT gave a higher surface area and a conductive matrix aiding to the sensing capabilities of the SnO2 increasing the effectiveness of the matrix material for gas detection. Copper is known to produce CNT with a disturb structure. To develop an electrode on copper with well-ordered CNT other techniques need to be used. One way to do this is by chemical modification of the copper substrate with a molecule able to react with the carbon nanotube. For the attachment of well-ordered carbon nanotubes such as SWCNT a self-assembly monolayer technique is chosen. On this study 4-aminothiophenol served as the linker between the copper substrate and the carbon nanotubes. This study let to chemically

  5. An ultrasensitive electrochemical DNA biosensor based on a copper oxide nanowires/single-walled carbon nanotubes nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mei [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Hou, Changjun, E-mail: houcj@cqu.edu.cn [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology, Chongqing University, Chongqing 400044 (China); Huo, Danqun [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology, Chongqing University, Chongqing 400044 (China); Yang, Mei [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Fa, Huanbao [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China)

    2016-02-28

    Graphical abstract: A novel and sensitive electrochemical biosensor based on hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH) was first developed for the detection of the specific-sequence target DNA. This schematic represents the fabrication procedure of our DNA biosensor. - Highlights: • An ultrasensitive DNA electrochemical biosensor was developed. • CuO NWs entangled with the SWCNTs formed a mesh structure with good conductivity. • It is the first time use of CuONWs-SWCNTs hybrid nanocomposite for DNA detection. • The biosensor is simple, selective, stable, and sensitive. • The biosensor has great potential for use in analysis of real samples. - Abstract: Here, we developed a novel and sensitive electrochemical biosensor to detect specific-sequence target DNA. The biosensor was based on a hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH). The resulting CuO NWs/SWCNTs layers exhibited a good differential pulse voltammetry (DPV) current response for the target DNA sequences, which we attributed to the properties of CuO NWs and SWCNTs. CuO NWs and SWCNTs hybrid composites with highly conductive and biocompatible nanostructure were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry (CV). Immobilization of the probe DNA on the electrode surface was largely improved due to the unique synergetic effect of CuO NWs and SWCNTs. DPV was applied to monitor the DNA hybridization event, using adriamycin as an electrochemical indicator. Under optimal conditions, the peak currents of adriamycin were linear with the logarithm of target DNA concentrations (ranging from 1.0 × 10{sup −14} to 1.0 × 10{sup −8} M), with a detection limit of 3.5 × 10{sup −15} M (signal/noise ratio of 3). The biosensor also showed high

  6. Immobilization of copper by biochar in Cu-enriched agricultural soils depends on interactions with soil organic carbon

    Science.gov (United States)

    Mlinkov, Slađana; Zehetner, Franz; Rosner, Franz; Dersch, Georg; Soja, Gerhard

    2017-04-01

    The appearance of downy mildew (Plasmopara viticola) in European vineyards of the 19th century was the starting point for the search of effective fungicides to avoid severe yield losses. Copper has been found as an important ingredient for several fungicides that have been used in agriculture and horticulture. For organic viticulture, several diseases can only be antagonized with Cu-containing fungicides as the application of organic fungicides is not permitted. This long-lasting dependence on Cu-fungicides has led to a gradual Cu enrichment of vineyard soils in traditional wine-growing areas, locally exceeding 300 mg/kg. Although these concentrations do not affect the vines or wine quality, they may impair soil microbiological functions in the top soil layer or the root growth of green cover plants. Therefore, measures are demanded that reduce the bioavailability of copper, thereby reducing the ecotoxicological effects. The use of biochar and compost as soil amendment has been suggested as a strategy to immobilize Cu and reduce the exchangeable fractions. In our study we have tested the hypothesis that biochar immobilizes the bioavailability of Cu for soil cover crops and reduces soil pore water concentrations. This study had the objective to test the interactions of compost and biochar with respect to Cu immobilization in vineyard soils. A Cu-enriched vineyard soil (250 mg Cu kg-1) was analyzed both in greenhouse and field experiments. In both experiments, soil with or without biochar and/or compost and mixtures of the two components were used. In the greenhouse experiments, was used as test plant Lolium multiflorum for Cu uptake; in the field, Lolium perenne and Trifolium repens were analyzed. Greenhouse experiment: Soil pore water concentrations showed clearer differences in Cu concentration than Lolium multiflorum shoots. Compost increased dissolved organic carbon (DOC) and Cu in soil pore water and biochar reduced it significantly. The mixtures of compost and

  7. Copper (II) Adsorption by Activated Carbons from Pecan Shells: Effect of Oxygen Level During Activation

    Science.gov (United States)

    Agricultural by-products represent a considerable quantity of harvested commodity crops. The use of by-products as precursors for the production of widely used adsorbents, such as activated carbons, may impart a value-added component of the overall biomass harvested. Our objective in this paper is...

  8. The Study of Corrosion and Wear Resistance of Copper Composite Coatings with Inclusions of Carbon Nanomaterials in the Copper Metal Matrix

    Directory of Open Access Journals (Sweden)

    Viktorija MEDELIENĖ

    2011-07-01

    Full Text Available This paper deals with the peculiarities of the behaviour of copper nanocomposite coatings with CNMs inclusions under the free corrosion conditions in the acidic medium. The parameters of corrosion current density (jcorr, anodic dissolution current density (ia and polarization resistance (Rp have been determined. In the acidic medium a stronger oxidation of nanostructured copper nanocomposites occurred. With longer immersion periods more corrosion products are formed, resulting in a increase in the polarization resistance (Rp of corrosion. Corrosion products cover the whole surface of the coatings and the corrosion rate (jcorr tends towards a steady value of 1.7×10-3 ¸ 2.1×10-3 A·cm-2 for all copper coatings studied: 1.7×10-3 A·cm-2 for both Cu and Cu-CNM1, 1.9×10-3 A·cm-2 - for Cu-CNM2 and 2.1×10-3 A·cm-2 - for Cu-CNM3 composite coatings. It has been established that nanocomposites possess a higher wear resistance as compared to that of pure copper. The damage of metal characterized as a depth scar (đ is lower. The roughness of the composites studied was found to be the essential factor affecting their wear resistance. Therefore, the wear resistance of nanocomposites is impaired when they are deposited on a hard steel substrate.http://dx.doi.org/10.5755/j01.ms.17.2.481

  9. The Study of Corrosion and Wear Resistance of Copper Composite Coatings with Inclusions of Carbon Nanomaterials in the Copper Metal Matrix

    Directory of Open Access Journals (Sweden)

    Viktorija MEDELIENĖ

    2011-07-01

    Full Text Available This paper deals with the peculiarities of the behaviour of copper nanocomposite coatings with CNMs inclusions under the free corrosion conditions in the acidic medium. The parameters of corrosion current density (jcorr, anodic dissolution current density (ia and polarization resistance (Rp have been determined. In the acidic medium a stronger oxidation of nanostructured copper nanocomposites occurred. With longer immersion periods more corrosion products are formed, resulting in a increase in the polarization resistance (Rp of corrosion. Corrosion products cover the whole surface of the coatings and the corrosion rate (jcorr tends towards a steady value of 1.7×10-3 ¸ 2.1×10-3 A·cm-2 for all copper coatings studied: 1.7×10-3 A·cm-2 for both Cu and Cu-CNM1, 1.9×10-3 A·cm-2 - for Cu-CNM2 and 2.1×10-3 A·cm-2 - for Cu-CNM3 composite coatings. It has been established that nanocomposites possess a higher wear resistance as compared to that of pure copper. The damage of metal characterized as a depth scar (đ is lower. The roughness of the composites studied was found to be the essential factor affecting their wear resistance. Therefore, the wear resistance of nanocomposites is impaired when they are deposited on a hard steel substrate.http://dx.doi.org/10.5755/j01.ms.17.2.481

  10. Copper-capped carbon nanocones on silicon: plasma-enabled growth control.

    Science.gov (United States)

    Kumar, Shailesh; Levchenko, Igor; Farrant, David; Keidar, Michael; Kersten, Holger; Ostrikov, Kostya Ken

    2012-11-01

    Controlled self-organized growth of vertically aligned carbon nanocone arrays in a radio frequency inductively coupled plasma-based process is studied. The experiments have demonstrated that the gaps between the nanocones, density of the nanocone array, and the shape of the nanocones can be effectively controlled by the process parameters such as gas composition (hydrogen content) and electrical bias applied to the substrate. Optical measurements have demonstrated lower reflectance of the nanocone array as compared with a bare Si wafer, thus evidencing their potential for the use in optical devices. The nanocone formation mechanism is explained in terms of redistribution of surface and volumetric fluxes of plasma-generated species in a developing nanocone array and passivation of carbon in narrow gaps where the access of plasma ions is hindered. Extensive numerical simulations were used to support the proposed growth mechanism.

  11. Surface Chemistry and Tribology of Copper Surfaces in Carbon Dioxide and Water Vapor Environments

    Science.gov (United States)

    2011-02-23

    progress). Simultaneous XAS and cyclic voltammetry of Cu in bicarbonate solutions under potentiostatic control at the Berkeley Synchrotron facility (Figure...bicarbonate ions that mimic the conditions of the wet brush-rotor contact. Electrochemical control of the surface by cyclic voltammetry makes it...the electrochemical modifications of Cu under potentiostat control and solution pH 3) Determine the loss of mass of Cu when in carbonate containing

  12. Virtual electrochemical nitric oxide analyzer using copper, zinc superoxide dismutase immobilized on carbon nanotubes in polypyrrole matrix.

    Science.gov (United States)

    Madasamy, Thangamuthu; Pandiaraj, Manickam; Balamurugan, Murugesan; Karnewar, Santosh; Benjamin, Alby Robson; Venkatesh, Krishna Arun; Vairamani, Kanagavel; Kotamraju, Srigiridhar; Karunakaran, Chandran

    2012-10-15

    In this work, we have designed and developed a novel and cost effective virtual electrochemical analyzer for the measurement of NO in exhaled breath and from hydrogen peroxide stimulated endothelial cells using home-made potentiostat. Here, data acquisition system (NI MyDAQ) was used to acquire the data from the electrochemical oxidation of NO mediated by copper, zinc superoxide dismutase (Cu,ZnSOD). The electrochemical control programs (graphical user-interface software) were developed using LabVIEW 10.0 to sweep the potential, acquire the current response and process the acquired current signal. The Cu,ZnSOD (SOD1) immobilized on the carbon nanotubes in polypyrrole modified platinum electrode was used as the NO biosensor. The electrochemical behavior of the SOD1 modified electrode exhibited the characteristic quasi-reversible redox peak at the potential, +0.06 V vs. Ag/AgCl. The biological interferences were eliminated by nafion coated SOD1 electrode and then NO was measured selectively. Further, this biosensor showed a wide linear range of response over the concentration of NO from 0.1 μM to 1 mM with a detection limit of 0.1 μM and high sensitivity of 1.1 μA μM(-1). The electroanalytical results obtained here using the developed virtual electrochemical instrument were also compared with the standard cyclic voltammetry instrument and found in agreement with each other.

  13. Preparation and Evaluation of Acetabularia-Modified Carbon Paste Electrode in Anodic Stripping Voltammetry of Copper and Lead Ions

    Directory of Open Access Journals (Sweden)

    Muhammad Raziq Rahimi Kooh

    2013-01-01

    Full Text Available Seaweed is well known about for potential in chelating heavy metals. In this study, carbon paste electrodes were fabricated with siphonous seaweed Acetabularia acetabulum as the modifiers to sense lead (II and copper (II by square-wave anodic stripping voltammetry. Various scan rates and deposition potentials were measured to obtain the optimal peak current for Pb(II and Cu(II. Optimum conditions of Acetabularia-CPE for sensing Pb(II were at the scan rate of 75 mV/s and deposition potential of −800 mV, while for Cu(II sensing were at 100 mV/s and −300 mV, respectively. The electrodes were characterized by the duration of accumulation time, preconcentration over a range of standards, supporting electrolyte, and standard solutions of various pH values. Interference studies were carried out. Both Zn(II and Cu(II were found to interfere with Pb(II sensing, whereas only Zn(II causes interference with Cu(II sensing. The electrode was found to have good regeneration ability via electrochemical cleaning. Preliminary testing of complex samples such as NPK fertilisers, black soil, and sea salt samples was included.

  14. An ultrasensitive electrochemical DNA biosensor based on a copper oxide nanowires/single-walled carbon nanotubes nanocomposite

    Science.gov (United States)

    Chen, Mei; Hou, Changjun; Huo, Danqun; Yang, Mei; Fa, Huanbao

    2016-02-01

    Here, we developed a novel and sensitive electrochemical biosensor to detect specific-sequence target DNA. The biosensor was based on a hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH). The resulting CuO NWs/SWCNTs layers exhibited a good differential pulse voltammetry (DPV) current response for the target DNA sequences, which we attributed to the properties of CuO NWs and SWCNTs. CuO NWs and SWCNTs hybrid composites with highly conductive and biocompatible nanostructure were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry (CV). Immobilization of the probe DNA on the electrode surface was largely improved due to the unique synergetic effect of CuO NWs and SWCNTs. DPV was applied to monitor the DNA hybridization event, using adriamycin as an electrochemical indicator. Under optimal conditions, the peak currents of adriamycin were linear with the logarithm of target DNA concentrations (ranging from 1.0 × 10-14 to 1.0 × 10-8 M), with a detection limit of 3.5 × 10-15 M (signal/noise ratio of 3). The biosensor also showed high selectivity to single-base mismatched target DNA. Compared with other electrochemical DNA biosensors, we showed that the proposed biosensor is simple to implement, with good stability and high sensitivity.

  15. Catalytic reduction of nitric oxide with carbon monoxide on copper-cobalt oxides supported on nano-titanium dioxide.

    Science.gov (United States)

    Chen, Xia; Zhang, Junfeng; Huang, Yan; Tong, Zhiquan; Huang, Ming

    2009-01-01

    A series of copper-cobalt oxides supported on nano-titanium dioxide were prepared for the reduction of nitric oxide with carbon monoxide and characterized using techniques such as XRD, BET and TPR. Catalyst CuCoOx/TiO2 with Cu/Co molar ratio of 1/2, Cu-Co total loading of 30% at the calcination temperature of 350 degrees C formed CuCo2O4 spinel and had the highest activity. NO conversion reached 98.9% at 200 degrees C. Mechanism of the reduction was also investigated, N2O was mainly yielded below 100 degrees C, while N2 was produced instead at higher temperature. O2 was supposed to accelerate the reaction between NOx and CO for its oxidation of NO to give more easily reduced NO2, but the oxidation of CO by O2 to CO2 decreased the speed of the reaction greatly. Either SO2 or H2O had no adverse impact on the activity of NO reduction; however, in the presence of both SO2 and H2O, the catalyst deactivated quickly.

  16. Facile fabrication of novel porous graphitic carbon nitride/copper sulfide nanocomposites with enhanced visible light driven photocatalytic performance.

    Science.gov (United States)

    Chen, Xi; Li, Huankun; Wu, Yuxin; Wu, Hanshuo; Wu, Laidi; Tan, Pengfei; Pan, Jun; Xiong, Xiang

    2016-08-15

    In this work, a novel organic-inorganic heterostructured photocatalyst: porous graphitic carbon nitride (g-C3N4) hybrid with copper sulfide (CuS) had been synthesized via a precipitation-deposition method at low temperature for the first time. UV-vis spectroscopy revealed the porous g-C3N4/CuS nanocomposites showed a strong and broad visible light absorption. Furthermore, the g-C3N4/CuS nanocomposites showed higher photocatalytic activity in the photodegradation of various organic dyes than that of pure g-C3N4 and CuS, and the selected sample of g-C3N4/CuS-2 exhibited the best photocatalytic activity under visible light. The good photocatalytic activity could be ascribed to the matching of the g-C3N4 and CuS band gap energies. Besides, photoluminescent spectra and photoelectrochemical measurements also proved that the CuS/g-C3N4 could greatly enhance the charge generation and suppress the charge recombination of photogenerated carriers. According to the experimental result, a possible photocatalytic mechanism has been proposed. Due to the high stability, the porous g-C3N4/CuS could be applied in the field of environmental remediation. Our work highlights that coupling semiconductors with well-matched band energies provides a facile way to improve the photocatalytic activity.

  17. Synergistic geometric and electronic effects for electrochemical reduction of carbon dioxide using gold-copper bimetallic nanoparticles

    National Research Council Canada - National Science Library

    Kim, Dohyung; Resasco, Joaquin; Yu, Yi; Asiri, Abdullah Mohamed; Yang, Peidong

    2014-01-01

    .... Here we assemble uniform gold-copper bimetallic nanoparticles with different compositions into ordered monolayers, which serve as a well-defined platform to understand their fundamental catalytic...

  18. Numerical Studies of Infiltration Dynamics of Liquid-Copper and Silicon/Solid-Carbon System

    Science.gov (United States)

    Iqbal, K.; Sha, J. J.; Lei, Zhen-Kun; Maqsood, A.; Mujahid, M.

    2014-06-01

    Mathematical modeling of infiltration dynamics of liquid Cu-Si alloy into porous carbon is presented. Two-dimensional infiltration equations are developed using the Washburn equation in the limit of both interface and diffusion control, for situations where the capillary radius decreases either linear or parabolic, and the contact angles are assumed to exponentially decrease with time during infiltration. One major manufacturing process for the Cu-Si/C composites is liquid melt infiltration. This article focuses on nonequilibrium wetting effects and offers a fundamental approach to these complex kinetic phenomena.

  19. Understanding the Photoluminescence Mechanism of Nitrogen-Doped Carbon Dots by Selective Interaction with Copper Ions.

    Science.gov (United States)

    Ganiga, Manjunatha; Cyriac, Jobin

    2016-08-04

    Doped fluorescent carbon dots (CDs) have drawn widespread attention because of their diverse applications and attractive properties. The present report focusses on the origin of photoluminescence in nitrogen-doped CDs (NCDs), which is unraveled by the interaction with Cu(2+) ions. Detailed spectroscopic and microscopic studies reveal that the broad steady-state photoluminescence emission of the NCDs originates from the direct recombination of excitons (high energy) and the involvement of defect states (low energy). In addition, highly selective detection of Cu(2+) is achieved, with a detection limit of 10 μm and a dynamic range of 10 μm-0.4 mm. The feasibility of the present sensor for the detection of Cu(2+) in real water samples is also presented. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Continuous Preparation of Copper/Carbon Nanotube Composite Films and Application in Solar Cells.

    Science.gov (United States)

    Luo, Xiao Gang; Le Wu, Min; Wang, Xiao Xia; Zhong, Xin Hua; Zhao, Ke; Wang, Jian Nong

    2016-02-08

    Realizing the continuous and large scale preparation of particle/carbon nanotube (CNT) composites with enhanced functionalities, and broad applications in energy conversion, harvesting, and storage systems, remains as a big challenge. Here, we report a scalable strategy to continuously prepare particle/CNT composite films in which particles are confined by CNT films. This is achieved by the continuous condensation and deposition of a cylindrical assembly of CNTs on a paper strip and the in situ incorporation of particles during the layer-by-layer deposition process. A Cu/CNT composite film is prepared as an example; such a film exhibits very high power conversion efficiency when it is used as a counter electrode in a solar cell, compared with previous materials under otherwise identical conditions. The proposed method can be extended to other CNT-based composite films with excellent functionalities for wide applications.

  1. Skin effect mitigation in laser processed multi-walled carbon nanotube/copper conductors

    Energy Technology Data Exchange (ETDEWEB)

    Keramatnejad, K.; Zhou, Y. S.; Gao, Y.; Rabiee Golgir, H.; Wang, M.; Lu, Y. F., E-mail: ylu2@unl.edu [Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States); Jiang, L. [School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081 (China); Silvain, J.-F. [Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB-CNRS) 87, Avenue du Docteur Albert Schweitzer F-33608 Pessac Cedex (France)

    2015-10-21

    In this study, laser-processed multi-walled carbon nanotube (MWCNT)/Cu conductors are introduced as potential passive components to mitigate the skin effect of Cu at high frequencies (0–10 MHz). Suppressed skin effect is observed in the MWCNT/Cu conductors compared to primitive Cu. At an AC frequency of 10 MHz, a maximum AC resistance reduction of 94% was observed in a MWCNT/Cu conductor after being irradiated at a laser power density of 189 W/cm{sup 2}. The reduced skin effect in the MWCNT/Cu conductors is ascribed to the presence of MWCNT channels which are insensitive to AC frequencies. The laser irradiation process is observed to play a crucial role in reducing contact resistance at the MWCNT-Cu interfaces, removing impurities in MWCNTs, and densifying MWCNT films.

  2. AUSTRALIAN PINE CONES-BASED ACTIVATED CARBON FOR ADSORPTION OF COPPER IN AQUEOUS SOLUTION

    Directory of Open Access Journals (Sweden)

    MUSLIM A.

    2017-02-01

    Full Text Available The Australian Pine cones (APCs was utilised as adsorbent material by physical and chemical activation for the adsorption Cu(II in aqueous solution. FTIR and SEM analysis were conducted to obtain the active site and to characterise the surface morphology of the APCs activated carbon (APCs AC prepared through pyrolysis at 1073.15 K and alkaline activation of NaOH. The independent variables effect such as contact time, Cu(II initial concentration and the activator ratio in the ranges of 0-150 min, 84.88-370.21 mg/l and 0.2-0.6 (NaOH:APCs AC, respectively on the Cu(II adsorption capacity were investigated in the APCs activated carbon-solution (APCs ACS system with 1 g the APCs AC in 100 mL Cu(II aqueous solution with magnetic stirring at 75 rpm, room temperature of 298.15 K (± 2 K, 1 atm and pH 5 (±0.25. As the results, Cu(II adsorption capacity dramatically increased with increasing contact time and Cu(II initial concentration. The optimal Cu(II adsorption capacity of 26.71 mg/g was obtained in the APCs ACS system with 120-min contact time, 340.81 m/l initial Cu(II and 0.6 activator ratio. The kinetics study showed the Cu(II adsorption kinetics followed the pseudo-second-order kinetics with 27.03 mg/g of adsorption capacity, 0.09 g/mg.min of rate constant and 0.985-R2. In addition, the Cu(II adsorption isotherm followed the Langmuir model with 12.82 mg/g of the mono-layer adsorption capacity, 42.93 l/g of the over-all adsorption capacity and 0.954-R2.

  3. Influence Of Temperature On The Rate Of Copper Recovery From The Slag Of The Flash Direct-To-Blister Process By A Solid Carbon Reducer

    Directory of Open Access Journals (Sweden)

    Madej P.

    2015-09-01

    Full Text Available The aim of the work was to investigate the influence of temperature on the rate of copper removal from the obtained slag from the flash direct-to-blister process by means of a carbon reducer. The slag used in this work was taken from the direct-to-blister Outokumpu flash furnace at the smelter in Głogów, and graphite penetrators were used as the slag reducers. The experiment was carried out at 1573 K, 1623 K and 1673 K. It was found that the rate of the de-coppering process of the “Głogów” slag increased with the increase of temperature.

  4. Hardness and wear resistance of carbon nanotube reinforced aluminum-copper matrix composites.

    Science.gov (United States)

    Nam, Dong Hoon; Kim, Jae Hwang; Cha, Seung Il; Jung, Seung Il; Lee, Jong Kook; Park, Hoon Mo; Park, Hyun Dal; Hong, Hyung

    2014-12-01

    Recently, carbon nanotubes (CNTs) have been attracted to reinforcement of composite materials due to their extraordinary mechanical, thermal and electrical properties. Many researchers have attempted to develop CNT reinforced metal composites with various fabrication methods and have shown possibilities for structural and functional applications. Among them, CNT reinforced Al matrix composites have become very attractive due to their huge structural application in industry. In this study, CNT reinforced Al-Cu matrix composites with a microstructure of homogeneous dispersion of CNTs in the Al-Cu matrix are investigated. The CNT/Al-Cu composites are fabricated by mixing of CNT/Cu composite powders and Al powders by high energy ball mill process followed by hot extrusion process. The hardness and wear resistance of the CNT/Al-Cu composites are enhanced by 1.4 and 3 times, respectively, compared to those values for the Al-Cu matrix. This remarkable enhancement mainly originates from the homogeneous dispersion of CNTs in Al-Cu matrix and self-lubricant effect of CNTs.

  5. Batch studies of adsorption of copper and lead on activated carbon from Eucalyptus camaldulensis Dehn. Bark

    Institute of Scientific and Technical Information of China (English)

    Phussadee Patnukao; Apipreeya Kongsuwan; Prasert Pavasant

    2008-01-01

    Powdered activated carbon (PAC) prepared from Eucalyptus camaldulensis Dehn. bark was tested for its adsorption capacity for Cu(Ⅱ) and Pb(Ⅱ). The experiment was conducted to investigate the effects of pH, contact time, initial metal concentration, and temperature. The best adsorption of both Cu(Ⅱ) and Pb(Ⅱ) occurred at pH 5, where the adsorption reached equilibrium within 45 min for the whole range of initial heavy metal concentrations (0.1-10 mmol/L). The adsorption kinetics was found to follow the pseudo-second order model where equilibrium adsorption capacities and adsorption rate constants increased with initial heavy metal concentrations. The adsorption isotherm followed Langmuir better than Freundlich models within the temperature range (25-60℃). The maximum adsorption capacities (qm) occurred at 60℃, where qm for Cu(Ⅱ) and Pb(Ⅱ) were 0.85 and 0.89 mmol/g, respectively. The enthalpies of Cu(Ⅱ) and Pb(Ⅱ) adsorption were 43.26 and 58.77 kJ/mol, respectively. The positive enthalpy of adsorption indicated an endothermic nature of the adsorption.

  6. Alleviation of copper-induced oxidative damage in Chlamydomonas reinhardtii by carbon monoxide.

    Science.gov (United States)

    Zheng, Qi; Meng, Qian; Wei, Yuan Yuan; Yang, Zhi Min

    2011-08-01

    Carbon monoxide (CO) is an endogenous gaseous molecule in plants and animals. Recent studies have shown that it is one of the most essential cellular components regulating many aspects of plant growth and development. However, whether CO regulates the green algae adaptive response to heavy metal toxicity is unknown. The present study investigated the role of CO in regulating Cu-induced oxidative stress in eukaryotic algae Chlamydomonas reinhardtii. Cells pretreated with 5 μM CO for 30 min and followed by exposure to 5 μM Cu(II) for 4 days showed attenuated toxicity. The CO-improved growth of algae was correlated with reduced lipid peroxidation and increased chlorophyll accumulation. The beneficial effect of CO was confirmed by histochemical staining with reactive oxygen species. Further, treatment with 5 μM CO increased the activity of catalase with Cu. However, a reduced superoxide dismutase activity was observed in the CO + Cu-treated algae compared to the control (activity of Cu treatment alone). Under the same condition, the activity of ascorbate peroxidase was not significantly changed. These results suggest that CO can play an important role in regulating the response of algae to Cu stress.

  7. Amino-functionalized mesoporous silica modified glassy carbon electrode for ultra-trace copper(II) determination

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Xingxin [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123 (China); Qiu, Fagui [Department of Quartermaster Engineering, Jilin University, No. 5333, Xi' an Road, Changchun 130062 (China); Zhou, Xuan [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123 (China); Long, Yumei, E-mail: yumeilong@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123 (China); The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou (China); Li, Weifeng, E-mail: liweifeng@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123 (China); Tu, Yifeng [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123 (China)

    2014-10-27

    NH{sub 2}-MCM-41 modified glassy carbon electrode was prepared and it exhibited enhanced anodic stripping response toward Cu (II), which could result from the large surface area of MCM-41 and the good chelating ability of amine-group. The as-constructed electrochemical sensor showed excellent analytical properties in the determination of Cu{sup 2+} and was successfully used for real sample assays. - Highlights: • We report a facile method to selectively detect Cu{sup 2+} based on NH{sub 2}-MCM-41 as sensing platform. • NH{sub 2}-MCM-41 has good affinity toward Cu{sup 2+}. • Detection limit of 0.9 ng L{sup −1} and linear concentration range of 5–1000 ng L{sup −1} are achieved. • The method is successfully applied to detect Cu{sup 2+} in real samples. - Abstract: This paper described a facile and direct electrochemical method for the determination of ultra-trace Cu{sup 2+} by employing amino-functionalized mesoporous silica (NH{sub 2}-MCM-41) as enhanced sensing platform. NH{sub 2}-MCM-41 was prepared by using a post-grafting process and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and fourier transform infrared (FTIR) spectroscopy. NH{sub 2}-MCM-41 modified glassy carbon (GC) electrode showed higher sensitivity for anodic stripping voltammetric (ASV) detection of Cu{sup 2+} than that of MCM-41 modified one. The high sensitivity was attributed to synergistic effect between MCM-41 and amino-group, in which the high surface area and special mesoporous morphology of MCM-41 can cause strong physical absorption, and amino-groups are able to chelate copper ions. Some important parameters influencing the sensor response were optimized. Under optimum experimental conditions the sensor linearly responded to Cu{sup 2+} concentration in the range from 5 to 1000 ng L{sup −1} with a detection limit of 0.9 ng L{sup −1} (S/N = 3). Moreover, the sensor possessed good stability and electrode renewability. In the end, the proposed

  8. Transformation behavior in low carbon 13% chromium-3% copper stainless steel; Tei C-13%Cr-3%Cu ko no hentai kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Hara, T.; Uemori, R.; Miyasaka, A. [Nippon Steel Corp., Tokyo (Japan)

    2000-10-01

    Martensitic transformation and {gamma} {yields} {alpha} transformation behavior were investigated in low carbon 13% chromium stainless steels containing 2% nickel or 3% copper. The main conclusions are as follows: (1) Hardness of 2% nickel added low carbon 13% chromium steel was independent of cooling rate after hot working at large reduction. Structure of the steel was martensitic even after being subjected to such large reduction of 75%. This result suggests that ferritic transformation was hard to occur under an usual cooling rate because austenite phase was sufficiently stablized by the addition of chromium and nickel. (2) Austenite to ferrite transformation occurred only for the low carbon 13% chromium 3% copper steel without nickel even at the small cooling rate, such as 0.01K/s. This result was mainly attributed to the unstabilization of austenite phase which caused by the precipitation of {epsilon}-Cu. Furthermore, austenite of the steel becomes easy to transform to ferrite due to heavy hot working. This phenomenon was seemed to be caused by the increase in the area of austenite grain boundary owing to recrystallization. Thus, it was considered that the nucleation of {epsilon}-Cu at the grain boundaries promoted ferrite formation. (author)

  9. Polymer-modified copper catalysts on carbon-containing support for reactions of H2O2 decomposition and cyclohexane oxidation

    Directory of Open Access Journals (Sweden)

    S. Auezkhanova

    2012-12-01

    Full Text Available Polymer-copper catalysts supported on a carbon-containing sorbent(CS, obtained by rice husk pyrolysis have been studied in the reactions of hydrogen peroxide decomposition and cyclohexane oxidation by hydrogen peroxide at 40°C and atmospheric pressure. The effect of the polymer nature on the activity of the developed catalysts have been shown. Polyhexamethyleneguanidine (PHMG was an optimal modifier for the developed catalysts. The calculated number of catalytic cycles (TON for 7% Cu-PGMG/CS was 450.

  10. Effect of Oxide Coating on Performance of Copper-Zinc Oxide-Based Catalyst for Methanol Synthesis via Hydrogenation of Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Tetsuo Umegaki

    2015-11-01

    Full Text Available The effect of oxide coating on the activity of a copper-zinc oxide–based catalyst for methanol synthesis via the hydrogenation of carbon dioxide was investigated. A commercial catalyst was coated with various oxides by a sol-gel method. The influence of the types of promoters used in the sol-gel reaction was investigated. Temperature-programmed reduction-thermogravimetric analysis revealed that the reduction peak assigned to the copper species in the oxide-coated catalysts prepared using ammonia shifts to lower temperatures than that of the pristine catalyst; in contrast, the reduction peak shifts to higher temperatures for the catalysts prepared using L(+-arginine. These observations indicated that the copper species were weakly bonded with the oxide and were easily reduced by using ammonia. The catalysts prepared using ammonia show higher CO2 conversion than the catalysts prepared using L(+-arginine. Among the catalysts prepared using ammonia, the silica-coated catalyst displayed a high activity at high temperatures, while the zirconia-coated catalyst and titania-coated catalyst had high activity at low temperatures. At high temperature the conversion over the silica-coated catalyst does not significantly change with reaction temperature, while the conversion over the zirconia-coated catalyst and titania-coated catalyst decreases with reaction time. From the results of FTIR, the durability depends on hydrophilicity of the oxides.

  11. Fabrication of new carbon paste electrodes based on gold nano-particles self-assembled to mercapto compounds as suitable ionophores for potentiometric determination of copper ions

    Directory of Open Access Journals (Sweden)

    Rasoul Pourtaghavi Talemi

    2013-12-01

    Full Text Available In the present study, we investigate the potentiometric behavior of Cu2+ carbon paste electrodes based on two mercapto compounds 2-ethylmino-5-mercapto-1,3,4-thiadiazole (EAMT and 2-acetylamino-5-mercapto-1,3,4-thiadiazole (AAMT self-assembled on gold nano-paricle (GNP as ionophore. Then, the obtained results from the modified electrodes are compared. The self-assembled ionophores exhibit a high selectivity for copper ion (Cu2+, in which the sulfur and nitrogen atoms in their structure play a significant role as the effective coordination donor site for the copper ion. Among these electrodes, the best performance was obtained with the sensor with a EAMT/graphite powder/paraffin oil weight ratio of 4.0/68/28 with 200 µL of GNP which exhibits the working concentration range of 1.6×10−9 to 6.3×10−2 M and a nernstian slope of 28.9±0.4 mVdecade−1 of copper(II activity. The detection limit of electrode was 2.9(±0.2×10−10M and potential response was pH ; in other words, it was independent across the range of 2.8–6.3. The proposed electrode presented very good selectivity and sensitivity towards the Cu2+ ions over a wide variety of cations including alkali, alkaline earth, transition and heavy metal ions. Moreover, the proposed electrode was successfully applied as an indicator electrode in the potentiometric titration of Cu(II ions with EDTA and also the potentiometric determination of copper ions in spiked water samples.

  12. Production of sulfur gases and carbon dioxide by synthetic weathering of crushed drill cores from the Santa Cruz porphyry copper deposit near Casa Grande, Pinal County, Arizona

    Science.gov (United States)

    Hinkle, M.E.; Ryder, J.L.; Sutley, S.J.; Botinelly, T.

    1990-01-01

    Samples of ground drill cores from the southern part of the Santa Cruz porphyry copper deposit, Casa Grande, Arizona, were oxidized in simulated weathering experiments. The samples were also separated into various mineral fractions and analyzed for contents of metals and sulfide minerals. The principal sulfide mineral present was pyrite. Gases produced in the weathering experiments were measured by gas chromatography. Carbon dioxide, oxygen, carbonyl sulfide, sulfur dioxide and carbon disulfide were found in the gases; no hydrogen sulfide, organic sulfides, or mercaptans were detected. Oxygen concentration was very important for production of the volatiles measured; in general, oxygen concentration was more important to gas production than were metallic element content, sulfide mineral content, or mineral fraction (oxide or sulfide) of the sample. The various volatile species also appeared to be interactive; some of the volatiles measured may have been formed through gas reactions. ?? 1990.

  13. 碳纤维表面单脉冲电镀铜%Carbon Coating on the Fiber Surface with Single Pulse Copper Plating

    Institute of Scientific and Technical Information of China (English)

    高嵩; 樊明杰; 王桂萍

    2011-01-01

    采用脉冲电镀法在碳纤维表面镀铜,研究了硫酸铜、硫酸、添加剂、施镀时间、电流密度、占空比等因素的影响,确定了合适的镀液成分和电镀工艺.采用冷热循环法检测镀层与碳纤维的结合力,采用SEM和XRD考察了铜镀层质量.结果表明,以130 g/L CuSO4·5H2O,g/L H2SO4 50,30 g/L KNO3及6 mL/L光亮剂为镀液、室温下电流密度82 μA/mm2、占空比40%、施镀时间6 min为电镀条件,可在碳纤维表面得到表面平整细致、结晶度良好的铜镀层.镀层结合力由原来的270kPa提高到450kPa.%Pulse copper plating was used to coat a copper film on the carbon fiber surface. The effects of CUSO4, H2SO4, additives, electroplating time, current density, and duty cycle on the weight gain rate were investigated. And the solution composition and technical parameters for pulse copper plating were determined. The bonding force between the coating and the carbon fiber was tested by psychro-thermal cycles. The quality of copper coating was examined with SEM and XRD. The composition of electroplating solution was 130 g/L CuSO4-5H2O, 50 g/L H2SO4, 30 g/L KNO3 and 6 mL/L brightener. Under ambient temperature, the optimum technical parameters were 82 μA/mm2 of current density, 40% of duty cycle, 6 min of electroplating time, with the conditions a flat, detailed and well-crystalloid coating on the carbon fiber surface was achieved. Coating adhesion was increased from 270 kPa to 450 kPa.

  14. Hierarchically Flower-like N-Doped Porous Carbon Materials Derived from an Explosive 3-Fold Interpenetrating Diamondoid Copper Metal-Organic Framework for a Supercapacitor.

    Science.gov (United States)

    Li, Zuo-Xi; Zou, Kang-Yu; Zhang, Xue; Han, Tong; Yang, Ying

    2016-07-05

    A peculiar copper metal-organic framework (Cu-MOF) was synthesized by a self-assembly method, which presents a 3-fold interpenetrating diamondoid net based on the square-planar Cu(II) node. Although it exhibits a high degree of interpenetration, the Cu-MOF still exhibits a one-dimensional channel, which provides a template for constructing porous materials through the "precursor" strategy. Furthermore, the explosive ClO4(-) ion, which resided in the channel, could induce the quick decomposition of organic ingredients and release a huge amount of gas, which is beneficial for the porosity of postsynthetic materials. Significantly, we first utilize this explosive MOF to prepare a series of Cu@C composites through the calcination-thermolysis method at different temperatures, which contain copper particles exhibiting various shapes and combinations with the carbon substrate. Considering the hole-forming effect of copper particles, Cu@C composites were etched by HCl to afford a sequence of hierarchically flower-like N-doped porous carbon materials (NPCs), which retain the original morphology of the Cu-MOF. Interestingly, NPC-900, originating from the calcination of the Cu-MOF at 900 °C, exhibits a more regular flower-like morphology, the largest specific surface area, abundant porosities, and multiple nitrogen functionalities. The remarkable specific capacitances are 138 F g(-1) at 5 mV s(-1) and 149 F g(-1) at 0.5 A g(-1) for the NPC-900 electrode in a 6 M potassium hydroxide aqueous solution. Moreover, the retention of capacitance remains 86.8% (125 F g(-1)) at 1 A g(-1) over 2000 cycles, which displays good chemical stability. These findings suggest that NPC-900 can be applied as a suitable electrode for a supercapacitor.

  15. Palladium Nanoparticles Immobilized on Individual Calcium Carbonate Plates Derived from Mussel Shell Waste: An Ecofriendly Catalyst for the Copper-Free Sonogashira Coupling Reaction.

    Science.gov (United States)

    Saetan, Trin; Lertvachirapaiboon, Chutiparn; Ekgasit, Sanong; Sukwattanasinitt, Mongkol; Wacharasindhu, Sumrit

    2017-09-05

    The conversion of waste into high-value materials is considered an important sustainability strategy in modern chemical industries. A large volume of shell waste is generated globally from mussel cultivation. In this work, mussel shell waste (Perna viridis) is transformed into individual calcium carbonate plates (ICCPs) and is applied as a support for a heterogeneous catalyst. Palladium nanoparticles (3-6 nm) are deposited with an even dispersion on the ICCP surface, as demonstrated by X-ray diffraction and scanning electron microscopy. Using this system, Sonogashira cross-coupling reactions between aryl iodides and terminal acetylenes were accomplished in high yields with the use of 1 % Pd/ICCP in the presence of potassium carbonate without the use of any copper metal or external ligand. The Pd/ICCP catalyst could also be reused up to three times and activity over 90 % was maintained with negligible Pd-metal leaching. This work demonstrates that mussel shell waste can be used as an inexpensive and effective support for metal catalysts in coupling reactions, as demonstrated by the successful performance of the Pd-catalyzed, copper-free Sonogashira cross-coupling process. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Determination of Lead, Copper and Iron Contents in Palladium-Carbon by ICP-AES%ICP-AES法测定钯炭中铅、铜和铁量

    Institute of Scientific and Technical Information of China (English)

    任传婷; 徐光; 唐发静; 李青; 马媛; 方卫; 李光俐; 甘建壮

    2015-01-01

    A simple accurate and precise analytical method for the determination of lead, copper and iron in palladium-carbon catalysts by ICP-AES was proposed. The digestion of sample which contains lead, copper and iron in the range between 0.01%~0.1% in fresh or spent palladium-carbon, was obtained using both HNO3 and HClO4. The recoveries were ranged from 95.8% to 100.9%. The precision, expressed as relative standard deviation (RSD) of the method, is better than 5%.%采用硝酸-高氯酸分解试样,ICP-AES法同时测定铅、铜和铁.建立了一个准确、快速、简便的测定方法,适用于新制和失效钯炭中铅、铜和铁量的测定.Pb、Cu、Fe测定范围为0.01%~0.1%;方法的加标回收率为95.8%~100.9%;相对标准偏差RSD<5%.

  17. Replacement of hazardous chromium impregnating agent from silver/copper/chromium-impregnated active carbon using triethylenediamine to remove hydrogen sulfide, trichloromethane, ammonia, and sulfur dioxide.

    Science.gov (United States)

    Wu, Li-Chun; Chung, Ying-Chien

    2009-03-01

    Activated carbon (AC) is widely used as an effective adsorbent in many applications, including industrial-scale air purification systems and air filter systems in gas masks. In general, ACs without chemical impregnation are good adsorbents of organic vapors but poor adsorbents of low-molecular-weight or polar gases such as chlorine, sulfur dioxide (SO2), formaldehyde, and ammonia (NH3). Impregnated ACs modified with metallic impregnating agents (ASC-carbons; e.g., copper, chromium, and silver) enhance the adsorbing properties of the ACs for simultaneously removing specific poisonous gases, but disposal of the chromium metal salt used to impregnate the ACs has the potential to result in situations that are toxic to both humans and the environment, thereby necessitating the search for replaceable organic impregnating agents that represent a much lower risk. The aim of this study was to assess the gas removal efficiency of an AC in which the organic impregnating agent triethylenediamine (TEDA) largely replaced the metallic impregnating agent chromium. We assessed batch and continuous adsorption capacities in situ for removing simulated hydrogen sulfide (H2S), trichloromethane (CHCl3), NH3, and SO2 gases. Brunauer-Emmet-Teller measurements and scanning electron microscopy analyses identified the removal mechanism by which TEDA-impregnated AS-carbon (dechromium ASC-carbon) adsorbs gases and determined the removal capacity for H2S, CHCl3, NH3, and SO2 to be 311, 258, 272, and 223 mg/g-C, respectively. These results demonstrate that TEDA-impregnated AS-carbon is significantly more efficient than ASC-carbon in adsorbing these four gases. Organic TEDA-impregnating agents have also been proven to be a reliable and environmental friendly agent and therefore a safe replacement of the hazardous chromium found in conventional ASC-carbon used in removing toxic gases from the airstream.

  18. Acetaldehyde as an Intermediate in the Electroreduction of Carbon Monoxide to Ethanol on Oxide-Derived Copper

    DEFF Research Database (Denmark)

    Bertheussen, Erlend; Verdaguer Casadevall, Arnau; Ravasio, Davide

    2016-01-01

    Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at −0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a mino...

  19. Acetaldehyde as an Intermediate in the Electroreduction of Carbon Monoxide to Ethanol on Oxide-Derived Copper

    DEFF Research Database (Denmark)

    Bertheussen, Erlend; Verdaguer Casadevall, Arnau; Ravasio, Davide

    2016-01-01

    Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at −0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a mino...

  20. Application of multiwall carbon nanotubes impregnated with 5-dodecylsalicylaldoxime for on-line copper preconcentration and determination in water samples by flame atomic absorption spectrometry.

    Science.gov (United States)

    Tobiasz, Anna; Walas, Stanisław; Soto Hernández, Arlene; Mrowiec, Halina

    2012-07-15

    The paper presents application of multiwall carbon nanotubes (MWCNTs) modified with 5-dodecylsalicylaldoxime to copper(II) flow-injection on-line preconcentration and flame atomic absorption spectrometric (FAAS) determination. Two new sorbents were obtained by impregnation of MWCNTs with Cu(II)-LIX 622(®) complex, however in the first case modification was preceded by carbon wall activation via oxidization (Cu-LIX-CNT-A sorbent), and in the second one no surface activation was performed (Cu-LIX-CNT sorbent). It was found that effective leaching of initially introduced copper and Cu(II) retained in preconcentration process could be realized with the use 7% and 5% (v/v) nitric acid, for particular sorbents. Testing the influence of loading solution pH and rate of loading on sorption it was found out that optimal range of loading solution pH was about 4.5-6.3 for activated and 6.15-6.25 for non-activated CNT. Investigation of sorption kinetics showed that the process can be described by pseudo-second order reaction model. Sorption equilibrium conditions (90% sorption) for LIX-CNT-A and LIX-CNT were obtained after 8-15min, respectively and maximum sorption capacity for the new sorbents amounted to 18.1mgg(-1) and 31.6mgg(-1), respectively. For the examined sorbents enrichment factors increased with extension of loading time up to 180s: linearly for activated and non-linearly for non-activated MWCNTs. Influence of potential interferents such as Cd(II), Zn(II), Fe(III), Mg(II) and Ca(II) ions on copper(II) sorption on the new CNT materials was examined individually and with the use of 2(5-2) factorial design. The study revealed significant interference from iron, magnesium and calcium ions at relatively high concentrations. Applicability of the proposed sorbents was tested for Cu(II) determination in various kinds of water samples and the results were compared with those obtained with the use of ICP MS as a reference technique. Copper(II) determination in two certified

  1. Influence of both the composition of impregnation solution and impregnation method on copper(II, chromium(VI and silver(I deposition on activated carbon

    Directory of Open Access Journals (Sweden)

    Ivanović Slavica

    2003-01-01

    Full Text Available The composition of a solution for impregnating activated carbon (AC for use in a gas filter was investigated. The solution components were tetraaminocop-per(II complex, chromium(VI, silver(l and carbonate ions. Two methods of impregnation were investigated: ion adsorption from aqueous solution in excess and the incipient wetness method. Copper, chromium and silver con-tents on AC Were determined by atomic absorption spectrometry. The largest copper contents (4.38 and 5.00 % (w/w for two AC samples were achieved at: c([Cu(NH34]2+ = 1.0 mol/L; M(Cu i M(Cr = 3.75: 1; M(Cu i M(Ag = 62: 1 and M(Cu: M(CO3 = 2: 1, using two fold impregnation by the incipient wetness method with 2.4 mL of solution per 3 g AC. The contents of chromium and silver on the same AC samples Were 1.06 and 0.0098 % for the first and 1.14 and 0.009 % for the second AC. A larger Cr content (1.57 % was achieved from an impregnation solution in excess (c([Cu(NH34]2+ = 1.25 mol/L; M(Cu i M(Cr = 3: 1; without Ag. The largest Ag content (0.17 % was obtained using two fold impregnation by the incipient wetness method (c([Cu(NH34]2+ = 0.8 mol/L; M(Cu: M(Cr = 3.75: 1<; M(Cu i M(Ag ( 80: 1 and M(Cu i M(CO3 = 1 i 1.32. Larger metal contents were obtained using two fold impregnation by the incipient wetness method. Further work is needed on the determination of the influence of carbonate ions both on the solution stability and metal deposition on AC.

  2. Copper hypersensitivity.

    Science.gov (United States)

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

    2014-10-01

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

  3. Optical properties of diamond like carbon films containing copper, grown by high power pulsed magnetron sputtering and direct current magnetron sputtering: Structure and composition effects

    Energy Technology Data Exchange (ETDEWEB)

    Meškinis, Š., E-mail: sarunas.meskinis@ktu.lt; Čiegis, A.; Vasiliauskas, A.; Šlapikas, K.; Tamulevičius, T.; Tamulevičienė, A.; Tamulevičius, S.

    2015-04-30

    In the present study chemical composition, structure and optical properties of hydrogenated diamond like carbon films containing copper (DLC:Cu films) deposited by reactive magnetron sputtering were studied. Different modes of deposition — direct current (DC) sputtering and high power pulsed magnetron sputtering (HIPIMS) as well as two configurations of the magnetron magnetic field (balanced and unbalanced) were applied. X-ray diffractometry, Raman scattering spectroscopy, energy-dispersive X-ray spectroscopy and atomic force microscopy were used to study the structure and composition of the films. It was shown that by using HIPIMS mode contamination of the cathode during the deposition of DLC:Cu films can be suppressed. In all cases oxygen atomic concentration in the films was in 5–10 at.% range and it increased with the copper atomic concentration. The highest oxygen content was observed in the films deposited employing low ion/neutral ratio balanced DC magnetron sputtering process. According to the analysis of the parameters of Raman scattering spectra, sp{sup 3}/sp{sup 2} bond ratio decreased with the increase of Cu atomic concentration in the DLC films. Clear dependence of the extinction, absorbance and reflectance spectra on copper atomic concentration in the films was observed independently of the method of deposition. Surface plasmon resonance effect was observed only when Cu atomic concentration in DLC:Cu film was at least 15 at.%. The maximum of the surface plasmon resonance peak of the absorbance spectra of DLC:Cu films was in 600–700 nm range and redshifted with the increase of Cu amount. The ratio between the intensities of the plasmonic peak and hydrogenated amorphous carbon related peak at ~ 220 nm both in the extinction and absorbance spectra as well as peak to background ratio of DLC:Cu films increased linearly with Cu amount in the investigated 0–40 at.% range. Reflectance of the plasmonic DLC:Cu films was in 30–50% range that could be

  4. Proof of concept for a novel, binder-free and conducting carbon-free sulfur battery cathode: Composite electroformation of copper foil with incorporated polythiophene wrapped sulfur particles

    Science.gov (United States)

    Erhardt, Claudia; Sörgel, Şeniz; Meinhard, Sandra; Sörgel, Timo

    2015-11-01

    This work, for the first time, presents sulfur electrodes for lithium/sulfur (Li/S) batteries produced by a newly developed single-step electroforming process, which allows simultaneous sulfur incorporation during electroformation of an electrically conducting electrode. This metal is used as binding matrix for the sulfur particles and thereby makes any binder and conducting carbon additives redundant. Furthermore, it serves by itself as the current collector, so that all functionalities (current collector, binder and electrical conductor towards sulfur) are fulfilled by the electroformed metal, while modified sulfur particles are directly incorporated (composite electroformation). In this way, the sulfur cathode can be produced in a single continuous step in form of a metal foil with adjustable thickness and sulfur loading. The process requires functionalization of sulfur to improve its wettability, incorporation homogeneity and volume which is provided by wrapping sulfur particles with polythiophene. Electroformed copper-sulfur composite foils are chosen as a first proof of the new concept. The achieved battery capacity, cycling stability and coulombic efficiency are presented. It is shown that the electroformed copper-sulfur composite foil operates very well as a battery cathode and a discharge capacity of over 400 mAh g-1 at a rate of 0.5 C over 100 cycles is preserved.

  5. Determination of Zinc, Cadmium, Lead, Copper and Silver Using a Carbon Paste Electrode and a Screen Printed Electrode Modified with Chromium(III Oxide

    Directory of Open Access Journals (Sweden)

    Zuzana Koudelkova

    2017-08-01

    Full Text Available In this study, the preparation and electrochemical application of a chromium(III oxide modified carbon paste electrode (Cr-CPE and a screen printed electrode (SPE, made from the same material and optimized for the simple, cheap and sensitive simultaneous determination of zinc, cadmium, lead, copper and the detection of silver ions, is described. The limits of detection and quantification were 25 and 80 µg·L−1 for Zn(II, 3 and 10 µg·L−1 for Cd(II, 3 and 10 µg·L−1 for Pb(II, 3 and 10 µg·L−1 for Cu(II, and 3 and 10 µg·L−1 for Ag(I, respectively. Furthermore, this promising modification was transferred to the screen-printed electrode. The limits of detection for the simultaneous determination of zinc, cadmium, copper and lead on the screen printed electrodes were found to be 350 µg·L−1 for Zn(II, 25 µg·L−1 for Cd(II, 3 µg·L−1 for Pb(II and 3 µg·L−1 for Cu(II. Practical usability for the simultaneous detection of these heavy metal ions by the Cr-CPE was also demonstrated in the analyses of wastewaters.

  6. Preparation of magnetic carbon nanotubes with hierarchical copper silicate nanostructure for efficient adsorption and removal of hemoglobin

    Science.gov (United States)

    Zhang, Min; Wang, Yongtao; Zhang, Yanwei; Ding, Lei; Zheng, Jing; Xu, Jingli

    2016-07-01

    The controllable synthesis of materials with the desired structure and dimensionality is of great significance in material science. In this work, the hierarchical CNTs/Fe3O4@copper silicate (CNTs/Fe3O4@CuSilicate) composites were synthesized via a simple chemical conversion route by using CNTs/Fe3O4@SiO2 nanocables as template. Firstly, magnetic CNTs composites (CNTs/Fe3O4) were synthesized by the high temperature decomposition process using the iron acetylacetonate as raw materials. Then a layer of SiO2 can be easily coated on the magnetic CNTs by the stöber method, which were then converted into CNTs/Fe3O4@CuSilicate composites by hydrothermal reaction between the silica shell and copper ions in alkaline solution. The resulting CNTs/Fe3O4@CuSilicate composites hold merits such as magnetic responsivity, good dispersibility, and large specific surface area. Moreover, the CNTs/Fe3O4@copper silicate composites have strong affinity toward bovine hemoglobin (BHb), which were successfully applied to convenient, efficient, and fast removal of abundant proteins (HHb and HSA) in human blood.

  7. Copper-spent activated carbon as a heterogeneous peroxydisulfate catalyst for the degradation of Acid Orange 7 in an electrochemical reactor.

    Science.gov (United States)

    Li, Jing; Lin, Heng; Yang, Lin; Zhang, Hui

    2016-01-01

    The exhausted activated carbon generated from the adsorption of heavy metal wastewater needs further treatment/disposal. In this study, a new application of copper-spent activated carbon (Cu-AC) was proposed. Cu-AC was used to activate peroxydisulfate (PDS) for the decolorization of Acid Orange 7 (AO7) and electrical current was introduced to enhance the process. The decolorization followed a pseudo-first-order kinetic pattern well (R(2) > 0.95). 92.4% of color removal at 60 min and 38.3% of total organic carbon removal at 180 min were achieved when initial pH value was 9.0, current density was 16 mA/cm(2), PDS concentration was 5 mM and Cu-AC dosage was 0.25 g/L. The radical scavengers including methanol, tert-butanol and phenol, as well as electron paramagnetic resonance test, were employed to investigate the oxidizing species responsible for AO7 decolorization. The stability of Cu-AC was confirmed by three recycle experiments.

  8. Copper transport.

    Science.gov (United States)

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.

  9. Synthesis, characterisation and adsorption properties of a porous copper(II) 3D coordination polymer exhibiting strong binding enthalpy and adsorption capacity for carbon dioxide.

    Science.gov (United States)

    Eckold, Pierre; Gee, William J; Hill, Matthew R; Batten, Stuart R

    2012-11-21

    The synthesis and characterisation of microporous coordination polymers containing copper(II) or cobalt(II) and 2-(pyridin-4-yl)malonaldehyde (Hpma) is described and the gas adsorption properties evaluated. Single-crystal X-ray structure determinations identified the structures as [M(pma)(2)]·2X (M = Cu, 1; Co, 2; X = MeOH, MeCN), which contain 3D networks with rutile topology and continuous 1D rectangular channels with diameters ranging from 3 to 4 Å. The materials exhibit low BET surface areas of 143 m(2) g(-1), but possess large capacities for carbon dioxide capture of 14.1 wt%. The small pore channels are shown to account for this, delivering a particularly strong binding enthalpy to adsorbed CO(2) of 38 kJ mol(-1), and a very large adsorption capacity relative to the low surface area.

  10. Application of artificial neural network to simultaneous potentiometric determination of silver(I), mercury(II) and copper(II) ions by an unmodified carbon paste electrode.

    Science.gov (United States)

    Shamsipur, Mojtaba; Tashkhourian, Javad; Hemmateenejad, Bahram; Sharghi, Hashem

    2004-10-20

    The response characteristics and selectivity coefficients of an unmodified carbon paste electrode (CPEs) towards Ag(+), Cu(2+) and Hg(2+) were evaluated. The electrode was used as an indicator electrode for the simultaneous determination of the three metal ions in their mixtures via potentiometric titration with a standard thiocyanate solution. A three-layered feed-forward artificial neural network (ANN) trained by back-propagation learning algorithm was used to model the complex non-linear relationship between the concentration of silver, copper and mercury in their different mixtures and the potential of solution at different volumes of the added titrant. The network architecture and parameters were optimized to give low prediction errors. The optimized networks were able to precisely predict the concentrations of the three cations in synthetic mixtures.

  11. The carbonate radical anion-induced covalent aggregation of human copper, zinc superoxide dismutase, and alpha-synuclein: intermediacy of tryptophan- and tyrosine-derived oxidation products.

    Science.gov (United States)

    Zhang, Hao; Andrekopoulos, Christopher; Joseph, Joy; Crow, John; Kalyanaraman, B

    2004-06-01

    In this review, we describe the free radical mechanism of covalent aggregation of human copper, zinc superoxide dismutase (hSOD1). Bicarbonate anion (HCO3-) enhances the covalent aggregation of hSOD1 mediated by the SOD1 peroxidase-dependent formation of carbonate radical anion (CO3*-), a potent and selective oxidant. This species presumably diffuses out the active site of hSOD1 and reacts with tryptophan residue located on the surface of hSOD1. The oxidative degradation of tryptophan to kynurenine and N-formyl kynurenine results in the covalent crosslinking and aggregation of hSOD1. Implications of oxidant-mediated aggregation of hSOD1 in the increased cytotoxicity of motor neurons in amyotrophic lateral sclerosis are discussed.

  12. Fabrication of electrochemical sensor for paracetamol based on multi-walled carbon nanotubes and chitosan-copper complex by self-assembly technique.

    Science.gov (United States)

    Mao, Airong; Li, Hongbo; Jin, Dangqin; Yu, Liangyun; Hu, Xiaoya

    2015-11-01

    An electrochemical sensor for paracetamol based on multi-walled carbon nanotubes and chitosan-copper complex (MWCNTs/CTS-Cu) was fabricated by self-assembly technique. The MWCNTs/CTS-Cu modified GCE showed an excellent electrocatalytic activity for the oxidation of paracetamol, and accelerated electron transfer between the electrode and paracetamol. Under optimal experimental conditions, the differential pulse peak current was linear with the concentration of paracetamol in the range of 0.1-200 μmol L(-1) with a detection limit of 0.024 μmol L(-1). The sensitivity was found to be 0.603 A/mol L(-1). The proposed sensor also showed a high selectivity for paracetamol in the presence of ascorbic acid and dopamine. Moreover, the proposed electrode revealed good reproducibility and stability. The proposed method was successfully applied for the determination of paracetamol in tablet and human serum samples.

  13. Performance of Thermal Radiation Energy on Stagnation-Point Flow In The Presence of Water Based Copper and Single Walled Carbon Nanotubes over Stretching/Shrinking Sheet

    Directory of Open Access Journals (Sweden)

    R. Kandasamy

    2016-04-01

    Full Text Available This article is expected for analyzing the impact of mixed convection flow of water based copper and single walled carbon nanotubes on a stagnation-point flow over a porous stretching/shrinking sheet subject to thermal energy radiation by utilizing numerical method. The governing PDEs are converted into nonlinear ODEs by using similarity transformation which is solved numerically using fifth-order Runge–Kutta–Fehlberg method with shooting technique (MAPLE 18. Both stretching and shrinking sheets, the influences of governing parameters are analyzed in graphical and tabular form and found that the SWCNTs–water exhibits higher mass transfer rates compared to Cu–water nanofluids with increase of chemical reaction.

  14. Copper hypersensitivity

    DEFF Research Database (Denmark)

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

    2014-01-01

    hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

  15. Highly active and selective catalysis of copper diphosphine complexes for the transformation of carbon dioxide into silyl formate.

    Science.gov (United States)

    Motokura, Ken; Kashiwame, Daiki; Takahashi, Naoki; Miyaji, Akimitsu; Baba, Toshihide

    2013-07-22

    Copper diphosphine complexes have been found to be highly active and selective homogeneous catalysts for the hydrosilylation of CO2. The structure of the phosphine ligands strongly affects their catalytic activity. Turnover number (TON) reaches 70,000 after 24 hours with 1,2-bis(diisopropylphosphino)benzene as a ligand under 1 atmosphere of CO2. (1)H and (13)C NMR spectra, carried out under the reaction conditions, showed the reaction mechanism through insertion of CO2 into Cu-H to afford Cu/formate species.

  16. Synthesis of phenolic precursor-based porous carbon beads in situ dispersed with copper-silver bimetal nanoparticles for antibacterial applications.

    Science.gov (United States)

    Khare, Prateek; Sharma, Ashutosh; Verma, Nishith

    2014-03-15

    Copper (Cu) and silver (Ag) bimetal-dispersed polymeric beads (~0.7 mm) were synthesized by suspension polymerization using phenol and formaldehyde monomers. The Cu:Ag bimetal nanoparticles (Nps) were incorporated into the polymeric matrix at the incipience of gel formation during polymerization using an anionic surfactant. The prepared bimetal-doped polymeric beads were carbonized, activated using steam, and reduced in a hydrogen atmosphere to produce metal Nps-doped porous carbon beads. The prepared bimetal (Cu and Ag) Nps-doped beads exhibited significantly larger anti-bacterial activities than single-(Cu or Ag) metal-doped beads for both gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria. The prepared materials contained the total optimized amounts of Cu and Ag. These amounts were smaller (approximately half) than the amount of single metal (Cu or Ag) required for preparing single-metal-doped beads. Although Cu Nps exhibit lesser antibacterial activity than Ag Nps, it enhanced the porosity of the beads. The prepared bimetal beads remained effective for 120 h, completely inhibiting the bacterial growth, and therefore, they are potential antibacterial agents for water purification.

  17. Growth Mechanism of Single-Walled Carbon Nanotubes on Iron–Copper Catalyst and Chirality Studies by Electron Diffraction

    DEFF Research Database (Denmark)

    He, Maoshuai; Liu, Bilu; Chernov, Alexander I.

    2012-01-01

    Chiralities of single-walled carbon nanotubes grown on an atomic layer deposition prepared bimetallic FeCu/MgO catalyst were evaluated quantitatively using nanobeam electron diffraction. The results reveal that the growth yields nearly 90% semiconducting tubes, 45% of which are of the (6,5) type...... by impregnation, showing similar catalytic performance as the atomic layer deposition-prepared catalyst, yielding single-walled carbon nanotubes with a similar narrow chirality distribution....

  18. Experimental study on comprehensive recycling of carbon,copper,silver,iron from zinc kiln slag%锌窑渣中碳铜银铁综合回收试验研究

    Institute of Scientific and Technical Information of China (English)

    董方; 高利坤; 陈龙; 王鹏; 马方通

    2016-01-01

    There are usually large amounts of carbon powders and many valuable metal elements in zinc kiln .The zinc kiln slag from Yunnan contains 22.31%carbon,1.33%copper and 294 g/t silver,23.41%iron and other val-uable elements ,which makes it have high recycling value .Based on the property of the zinc kiln slag ,the paper carried out experimental study on a combined flotation -magnetic separation process .The results show that the process can ob-tain carbon powders with carbon grade of 78.55 %,carbon recovery rate of 92.60 %;copper concentrates with cop-per grade of 8.13 %,copper recovery rate of 78.61 % and Ag grade of 1890 g/t; and iron concentrates with iron grade of 66.02 %,iron recovery rate of 76.33 %.A fairly high recovery rate is achieved .%锌窑渣通常含有大量炭粉和许多有价金属元素.云南某锌窑渣中含碳22.31%、铜1.33%、银294 g/t、铁23.41%等有价元素,具有较高的回收利用价值.针对该锌窑渣的性质,进行了浮选—磁选联合工艺试验研究.其结果表明:该工艺可获得碳品位78.55%、碳回收率92.60%的炭粉,铜品位8.13%、铜回收率78.61%、含银1890 g/t的铜精矿以及铁品位66.02%、铁回收率76.33%的铁精矿,且均实现了较高的回收率.

  19. Copper determination in ethanol fuel by differential pulse anodic stripping voltammetry at a solid paraffin-based carbon paste electrode modified with 2-aminothiazole organofunctionalized silica.

    Science.gov (United States)

    Takeuchi, Regina M; Santos, André L; Padilha, Pedro M; Stradiotto, Nelson R

    2007-02-15

    Solid paraffin-based carbon paste electrodes modified with 2-aminothiazole organofunctionalized silica have been applied to the anodic stripping determination of copper ions in ethanol fuel samples without any sample treatment. The proposed method comprised four steps: (1) copper ions preconcentration at open circuit potential directly in the ethanol fuel sample; (2) exchange of the solution and immediate cathodic reduction of the absorbate at controlled potential; (3) differential pulse anodic stripping voltammetry; (4) electrochemical surface regeneration by applying a positive potential in acid media. Factors affecting the preconcentration, reduction and stripping steps were investigated and the optimum conditions were employed to develop the analytical procedure. Using a preconcentration time of 20min and reduction time of 120s at -0.3V versus Ag/AgCl(sat) a linear range from 7.5x10(-8) to 2.5x10(-6)mol L(-1) with detection limit of 3.1x10(-8)mol L(-1) was obtained. Interference studies have shown a decrease in the interference effect according to the sequence: Ni>Zn>Cd>Pb>Fe. However, the interference effects of these ions have not forbidden the application of the proposed method. Recovery values between 98.8 and 102.3% were obtained for synthetic samples spiked with known amounts of Cu(2+) and interfering metallic ions. The developed electrode was successfully applied to the determination of Cu(2+) in commercial ethanol fuel samples. The results were compared to those obtained by flame atomic absorption spectroscopy by using the F-test and t-test. Neither F-value nor t-value have exceeded the critical values at 95% confidence level, confirming that there are no significant differences between the results obtained by both methods.

  20. 高铜载金炭过硫酸盐法脱铜试验研究%Decoppering From High-copper Activated Carbon Carrying Gold by Persulfate Process

    Institute of Scientific and Technical Information of China (English)

    陈淑萍

    2015-01-01

    采用过硫酸盐脱铜工艺处理高铜载金炭,可选择性地脱除载金炭中的铜,铜脱除率达89%,金损失率很低;脱铜溶液循环后采用萃取—电积工艺回收铜。该工艺流程短,药剂用量少,处理时间短,环境友好,铜脱除率高,成本低,具有较好的应用前景。%The decoppering from high copper activated carbon carrying gold by a persulfate solution were described .By this method ,removal rate of copper in gold‐bearing carbon can reach 90% while gold loss rate is very low .Recovery of copper from copper solution by solvent extraction process .This process has the advantages of short process ,low regent dosage ,short treatment time ,high environmental friendliness ,low cost ,and so on .It has good application prospect .

  1. Remediation of actual groundwater polluted with nitrate by the catalytic reduction over copper-palladium supported on active carbon

    OpenAIRE

    Wang, Yi; Sakamoto, Yoshinori; Kamiya, Yuichi

    2009-01-01

    Catalytic reduction of nitrate (NO3-) in groundwater over a Cu-Pd catalyst supported on active carbon was investigated in a gas-liquid co-current flow system at 298 K. Although Cu-Pd/active carbon, in which the Cu/Pd molar ratio was more than 0.66, showed high activity, high selectivity for the formation of N2 and N2O (98%), and high durability for the reduction of 100 ppm NO3- in distilled water, the catalytic performance decreased during the reduction of NO3- in groundwater. The catalyst al...

  2. POLYKETONE FROM ETHYLENE WITH CARBON MONOXIDE CATALYZED BY NOVEL CATALYST SYSTEMS BASED ON COPPER WITH BIDENTATE PHOSPHORUS CHELATING LIGANDS

    Institute of Scientific and Technical Information of China (English)

    Jun Huang; Feng-bo Li; Jin Zou; Guo-qing Yuan; Xiu-li Shi; Ding-sheng Yu

    2003-01-01

    Copolymerization of ethylene with carbon monoxide was performed with Cu catalyst systems. Novel catalyst systems based on Cu (Cu(CH3COO)2/ligand/acid) were firstly reported for the copolymerization of ethylene with carbon monoxide, in which the ligand was a bidentate phosphorus chelating ligand. The experimental results showed that this kind of Cu catalyst system exhibited high activity. When DPPP (1,3-bis(diphenylphosphine)propane) and CH3COOH were used catalyst system had the advantages of high stability and low cost.

  3. One-pot green synthesis of N-doped carbon quantum dots for cell nucleus labelling and copper (Ⅱ) detection.

    Science.gov (United States)

    Ci, Jiliang; Tian, Ye; Kuga, Shigenori; Niu, Zhongwei; Wu, Min; Huang, Yong

    2017-09-21

    The doping of nitrogen into carbon quantum dots was vitally important for improvement of fluorescence performance. However, the synthesis of nitrogen-doped carbon quantum dots (N-CQDs) was usually conducted under strong acid and high temperature, which would result in the environmental pollution and energy consumption. Herein, the N-CQDs were prepared by a mild one-pot hydrothermal process. The hydrothermal reaction temperature was adjusted to control the particle size, N/C atomic ratio and quantum yield. The products were water-soluble with narrow particle size distribution and good dispersion stability in wide pH range. The N-CQDs could penetrate into HeLa cell nucleus without any further functionalization. Moreover, the fluorescence of N-CQDs could be selectively quenched by Cu2+, suggesting application of detecting Cu2+ in human plasma. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Copper indium disulfide nanocrystals supported on carbonized chicken eggshell membranes as efficient counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Wang, Lidan; He, Jianxin; Zhou, Mengjuan; Zhao, Shuyuan; Wang, Qian; Ding, Bin

    2016-05-01

    A domestic waste, chicken eggshell membrane (ESM), is used as a raw material to fabricate carbonized ESM loaded with chalcopyrite CuInS2 nanocrystals (denoted CESM-CuInS2) by a simple liquid impregnation and carbonization method. The CESM-CuInS2 composite possesses a natural three-dimensional macroporous network structure in which numerous CuInS2 nanocrystals with a size of about 25 nm are inlaid in carbon submicron fibers that form a microporous network. The CESM-CuInS2 composite is used as the counter electrode in a dye-sensitized solar cell (DSSC) and its photoelectric performance is tested. The DSSC with a CESM-CuInS2 counter electrode exhibits a short-circuit current density of 12.48 mA cm-2, open-circuit voltage of 0.78 V and power conversion efficiency of 5.8%; better than the corresponding values for a DSSC with a CESM counter electrode, and comparable to that of a reference DSSC with a platinum counter electrode. The favorable photoelectric performance of the CESM-CuInS2 counter electrode is attributed to its hierarchical structure, which provides a large specific surface area and numerous catalytically active sites to facilitate the oxidation of the electrolyte. This new composite material has many advantages, such as low cost and simple preparation, compared with Pt and pure CuInS2 counter electrodes.

  5. Catalytic Chemical Vapor Deposition of Methane to Carbon Nanotubes: Copper Promoted Effect of Ni/MgO Catalysts

    Directory of Open Access Journals (Sweden)

    Wen Yang

    2014-01-01

    Full Text Available The Ni/MgO and Ni-Cu/MgO catalysts were prepared by sol-gel method and used as the catalysts for synthesis of carbon nanotubes by thermal chemical vapor deposition. The effect of Cu on the carbon yield and structure was investigated, and the effects of calcination temperature and reaction temperature were also investigated. The catalysts and synthesized carbon materials were characterized by temperature programmed reduction (TPR, thermogravimetric analysis (TGA, and scanning electron microscopy (SEM. Results showed that the addition of Cu promoted the reduction of nickel species, subsequently improving the growth and yield of CNTs. Meanwhile, CNTs were synthesized by the Ni/MgO and Ni-Cu/MgO catalysts with various calcination temperatures and reaction temperatures, and results suggested that the obtained CNTs on Ni-Cu/MgO catalyst with the calcination temperature of 500°C and the reaction temperature of 650°C were of the greatest yield and quantity of 927%.

  6. Simultaneous removal of atrazine and copper using polyacrylic acid-functionalized magnetic ordered mesoporous carbon from water: adsorption mechanism

    Science.gov (United States)

    Zhou, Yaoyu; Zhang, Fengfeng; Tang, Lin; Zhang, Jiachao; Zeng, Guangming; Luo, Lin; Liu, Yuanyuan; Wang, Pei; Peng, Bo; Liu, Xiaocheng

    2017-03-01

    Highly efficient simultaneous removal of atrazine and Cu(II) was accomplished using synthesized polyacrylic acid-functionalized magnetic ordered mesoporous carbon (P-MMC) as compared to magnetic ordered mesoporous carbon (MMC) and ordered mesoporous carbon (OMC). The mutual effects and interactive mechanism of their adsorption onto P-MMC were investigated systematically by binary, preloading and thermodynamic adsorption procedures. In both binary and preloading systems, the adsorption of atrazine was inhibited to some extent by the presence of Cu(II) because of selective recognition and direct competition, but the presence of atrazine had negligible effect on Cu(II) desorption. With the coexistence of humic acid (0-20 mg L-1), both atrazine and Cu(II) sorption increased slightly in sole and binary systems. With the concentration of coexisting NaCl increasing from 0 to 100 mM, the adsorption capacity for Cu(II) slightly decreased, but as for atrazine adsorption, it decreased at first, and then increased slightly in sole and binary systems. P-MMC was applied to treat real environmental samples, and the sorption capacities for atrazine and Cu(II) in real samples were all more than 91.47% and 96.43% of those in lab ultrapure water, respectively. Finally, comprehensively considering the relatively good renewability and the superior behavior in the application to real water samples, P-MMC has potential in removal of atrazine, Cu(II) and possibly other persistent organic pollutants from wastewater.

  7. Removal of copper (II) from aqueous solutions by flotation using polyaluminum chloride silicate (PAX-XL60 S) as coagulant and carbonate ion as activator.

    Science.gov (United States)

    Ghazy, S E; Mahmoud, I A; Ragab, A H

    2006-01-01

    Flotation is a separation technology for removing toxic heavy metal ions from aqueous solutions. Here a simple and rapid flotation procedure is presented for the removal of copper(II) from aqueous solutions. It is based on the use of polyaluminum chloride silicate (PAX-XL60 S) as coagulant and flocculent, carbonate ion as activator and oleic acid (HOL) as surfactant. Both ion and precipitate flotation are included depending on the solution pH. Ion and precipitate flotation in the aqueous HOL-PAX-XL60 S-Cu2+-CO3(2-) system gave powerful preferential removal of Cu2+ (F -100%) over the HOL-PAX-XL60 S-Cu2+ system containing no CO3(2+) ion (F approximately 86%). The role of CO3(2-) ion is also evident from decreasing the dose of PAX-XL60 S from 700 mg l(-1) to 200 mg l(-1). The other parameters, influencing the flotation process, namely: metal ion, surfactant and PAX-XL60 S concentrations, ionic strength, temperature and foreign ions were examined. Moreover, the procedure was successfully applied to recover Cu2+ ions from different volumes up to 11 and from natural water samples.

  8. Large-angle production of charged pions by 3 GeV/c - 12 GeV/c protons on carbon, copper and tin targets

    CERN Document Server

    Catanesi, M.G.; Ellis, Malcolm; Robbins, S.; Soler, F.J.P.; Gossling, C.; Bunyatov, S.; Krasnoperov, A.; Popov, B.; Serdiouk, V.; Tereschenko, V.; Di Capua, E.; Vidal-Sitjes, G.; Artamonov, A.; Arce, P.; Giani, S.; Gilardoni, S.; Gorbunov, P.; Grant, A.; Grossheim, A.; Gruber, P.; Ivanchenko, V.; Kayis-Topaksu, A.; Panman, J.; Papadopoulos, I.; Pasternak, J.; Tcherniaev, E.; Tsukerman, I.; Veenhof, R.; Wiebusch, C.; Zucchelli, P.; Blondel, A.; Borghi, S.; Campanelli, M.; Morone, M.C.; Prior, G.; Schroeter, R.; Engel, R.; Meurer, C.; Kato, I.; Gastaldi, U.; Mills, G.B.; Graulich, J.S.; Gregoire, G.; Bonesini, M.; Ferri, F.; Paganoni, M.; Paleari, F.; Kirsanov, M.; Bagulya, A.; Grichine, V.; Polukhina, M.; Palladino, V.; Coney, L.; Schmitz, D.; Barr, G.; De Santo, A.; Pattison, C.; Zuber, K.; Bobisut, F.; Gibin, D.; Guglielmi, A.; Mezzetto, M.; Dumarchez, J.; Vannucci, F.; Dore, U.; Orestano, D.; Pastore, F.; Tonazzo, A.; Tortora, L.; Booth, C.; Buttar, C.; Hodgson, P.; howlett, L.; Bogomilov, M.; Chizhov, M.; Kolev, D.; Tsenov, R.; Piperov, Stefan; Temnikov, P.; Apollonio, M.; Chimenti, P.; Giannini, G.; Santin, G.; Burguet-Castell, J.; Cervera-Villanueva, A.; Gomez-Cadenas, J.J.; Martin-Albo, J.; Novella, P.; Sorel, M.; Tornero, A.

    2008-01-01

    A measurement of the double-differential $\\pi^{\\pm}$ production cross-section in proton--carbon, proton--copper and proton--tin collisions in the range of pion momentum $100 \\MeVc \\leq p < 800 \\MeVc$ and angle $0.35 \\rad \\le \\theta <2.15 \\rad$ is presented. The data were taken with the HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 \\GeVc to 12 \\GeVc hitting a target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was done using a small-radius cylindrical time projection chamber (TPC) placed in a solenoidal magnet. An elaborate system of detectors in the beam line ensured the identification of the incident particles. Results are shown for the double-differential cross-sections at four incident proton beam momenta (3 \\GeVc, 5 \\GeVc, 8 \\GeVc and 12 \\GeVc).

  9. Large-angle production of charged pions by 3 GeV/c - 12 GeV/c protons on carbon, copper and tin targets

    CERN Document Server

    Catanesi, M G; Edgecock, R; Ellis, M; Robbins, S; Soler, F J P; Gössling, C; Bunyatov, S; Krasnoperov, A; Popov, B; Serdiouk, V; Tereschenko, V; Di Capua, E; Vidal-Sitjes, G; Artamonov, A; Arce, P; Giani, S; Gilardoni, S; Gorbunov, P; Grant, A; Grossheim, A; Gruber, P; Ivanchenko, V; Kayis-Topaksu, A; Panman, J; Papadopoulos, I; Pasternak, J; Chernyaev, E; Tsukerman, I; Veenhof, R; Wiebusch, C; Zucchelli, P; Blondel, A; Borghi, S; Campanelli, M; Morone, M C; Prior, G; Schroeter, R; Engel, R; Meurer, C; Kato, I; Gastaldi, Ugo; Mills, G B; Graulich, J S; Grégoire, G; Bonesini, M; Ferri, F; Paganoni, M; Paleari, F; Kirsanov, M; Bagulya, A; Grichine, V; Polukhina, N; Palladino, V; Coney, L; Schmitz, D; Barr, G; De Santo, A; Pattison, C; Zuber, K; Bobisut, F; Gibin, D; Guglielmi, A; Mezzetto, M; Dumarchez, J; Vannucci, F; Dore, U; Orestano, D; Pastore, F; Tonazzo, A; Tortora, L; Booth, C; Buttar, C; Hodgson, P; Howlett, L; Bogomilov, M; Chizhov, M; Kolev, D; Tsenov, R; Piperov, S; Temnikov, P; Apollonio, M; Chimenti, P; Giannini, G; Santin, G; Burguet-Castell, J; Cervera-Villanueva, A; Gómez-Cadenas, J J; Martín-Albo, J; Novella, P; Sorel, M; Tornero, A

    2008-01-01

    A measurement of the double-differential $\\pi^{\\pm}$ production cross-section in proton--carbon, proton--copper and proton--tin collisions in the range of pion momentum $100 \\MeVc \\leq p < 800 \\MeVc$ and angle $0.35 \\rad \\le \\theta <2.15 \\rad$ is presented. The data were taken with the HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 \\GeVc to 12 \\GeVc hitting a target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was done using a small-radius cylindrical time projection chamber (TPC) placed in a solenoidal magnet. An elaborate system of detectors in the beam line ensured the identification of the incident particles. Results are shown for the double-differential cross-sections at four incident proton beam momenta (3 \\GeVc, 5 \\GeVc, 8 \\GeVc and 12 \\GeVc).

  10. Aminoarenethiolate-Copper(I)-Catalyzed Amination of Aryl Bromides

    NARCIS (Netherlands)

    Jerphagnon, Thomas; Klink, Gerard P.M. van; Vries, Johannes G. de; Koten, Gerard van

    2005-01-01

    Aminoarenethiolate-copper(I) complexes are known to be efficient catalysts for carbon-carbon bond formation. Here, we show the first examples that these thiolate-copper(I) complexes are efficient for carbon-nitrogen bond formation reactions as well. N-Arylation of benzylamine and imidazole with

  11. Aminoarenethiolate-Copper(I)-Catalyzed Amination of Aryl Bromides

    NARCIS (Netherlands)

    Jerphagnon, Thomas; Klink, Gerard P.M. van; Vries, Johannes G. de; Koten, Gerard van

    2005-01-01

    Aminoarenethiolate-copper(I) complexes are known to be efficient catalysts for carbon-carbon bond formation. Here, we show the first examples that these thiolate-copper(I) complexes are efficient for carbon-nitrogen bond formation reactions as well. N-Arylation of benzylamine and imidazole with brom

  12. Ratiometric fluorescent paper sensor utilizing hybrid carbon dots-quantum dots for the visual determination of copper ions

    Science.gov (United States)

    Wang, Yahui; Zhang, Cheng; Chen, Xiaochun; Yang, Bo; Yang, Liang; Jiang, Changlong; Zhang, Zhongping

    2016-03-01

    A simple and effective ratiometric fluorescence nanosensor for the selective detection of Cu2+ has been developed by covalently connecting the carboxyl-modified red fluorescent cadmium telluride (CdTe) quantum dots (QDs) to the amino-functionalized blue fluorescent carbon nanodots (CDs). The sensor exhibits the dual-emissions peaked at 437 and 654 nm, under a single excitation wavelength of 340 nm. The red fluorescence can be selectively quenched by Cu2+, while the blue fluorescence is a internal reference, resulting in a distinguishable fluorescence color change from pink to blue under a UV lamp. The detection limit of this highly sensitive ratiometric probe is as low as 0.36 nM, which is lower than the U.S. Environmental Protection Agency (EPA) defined limit (20 μM). Moreover, a paper-based sensor has been prepared by printing the hybrid carbon dots-quantum dots probe on a microporous membrane, which provides a convenient and simple approach for the visual detection of Cu2+. Therefore, the as-synthesized probe shows great potential application for the determination of Cu2+ in real samples.A simple and effective ratiometric fluorescence nanosensor for the selective detection of Cu2+ has been developed by covalently connecting the carboxyl-modified red fluorescent cadmium telluride (CdTe) quantum dots (QDs) to the amino-functionalized blue fluorescent carbon nanodots (CDs). The sensor exhibits the dual-emissions peaked at 437 and 654 nm, under a single excitation wavelength of 340 nm. The red fluorescence can be selectively quenched by Cu2+, while the blue fluorescence is a internal reference, resulting in a distinguishable fluorescence color change from pink to blue under a UV lamp. The detection limit of this highly sensitive ratiometric probe is as low as 0.36 nM, which is lower than the U.S. Environmental Protection Agency (EPA) defined limit (20 μM). Moreover, a paper-based sensor has been prepared by printing the hybrid carbon dots-quantum dots probe on a

  13. Seed-mediated synthesis of copper nanoparticles on carbon nanotubes and their application in nonenzymatic glucose biosensors.

    Science.gov (United States)

    Lu, Li-Min; Zhang, Xiao-Bing; Shen, Guo-Li; Yu, Ru-Qin

    2012-02-17

    In this paper, for the first time, Cu nanoparticles (CuNPs) were prepared by seed-mediated growth method with Au nanoparticles (AuNPs) playing the role of seeds. Carbon nanotubes (CNTs) and AuNPs were first dropped on the surface of glassy carbon (GC) electrode, and then the electrode was immersed into growth solution that contained CuSO(4) and hydrazine. CuNPs were successfully grown on the surface of the CNTs. The modified electrode showed a very high electrochemical activity for electrocatalytic oxidation of glucose in alkaline medium, which was utilized as the basis of the fabrication of a nonenzymatic biosensor for electrochemical detection of glucose. The biosensor can be applied to the quantification of glucose with a linear range covering from 1.0×10(-7) to 5×10(-3)M and a low detection limit of 3×10(-8)M. Furthermore, the experiment results also showed that the biosensor exhibited good reproducibility and long-term stability, as well as high selectivity with no interference from other oxidable species. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Ratiometric fluorescent paper sensor utilizing hybrid carbon dots-quantum dots for the visual determination of copper ions.

    Science.gov (United States)

    Wang, Yahui; Zhang, Cheng; Chen, Xiaochun; Yang, Bo; Yang, Liang; Jiang, Changlong; Zhang, Zhongping

    2016-03-21

    A simple and effective ratiometric fluorescence nanosensor for the selective detection of Cu(2+) has been developed by covalently connecting the carboxyl-modified red fluorescent cadmium telluride (CdTe) quantum dots (QDs) to the amino-functionalized blue fluorescent carbon nanodots (CDs). The sensor exhibits the dual-emissions peaked at 437 and 654 nm, under a single excitation wavelength of 340 nm. The red fluorescence can be selectively quenched by Cu(2+), while the blue fluorescence is a internal reference, resulting in a distinguishable fluorescence color change from pink to blue under a UV lamp. The detection limit of this highly sensitive ratiometric probe is as low as 0.36 nM, which is lower than the U.S. Environmental Protection Agency (EPA) defined limit (20 μM). Moreover, a paper-based sensor has been prepared by printing the hybrid carbon dots-quantum dots probe on a microporous membrane, which provides a convenient and simple approach for the visual detection of Cu(2+). Therefore, the as-synthesized probe shows great potential application for the determination of Cu(2+) in real samples.

  15. Silicon- and tin-based cuprates: now catalytic in copper!

    Science.gov (United States)

    Weickgenannt, Andreas; Oestreich, Martin

    2010-01-11

    Silicon- and tin-containing molecules are versatile building blocks in organic synthesis. A stalwart method for their preparation relies on the stoichiometric use of silicon- and tin-based cuprates, although a few copper(I)-catalyzed or even copper-free protocols have been known for decades. In this Concept, we describe our efforts towards copper(I)-catalyzed carbon--silicon and also carbon--tin bond formations using soft bis(triorganosilyl) and bis(triorganostannyl) zinc reagents as powerful sources of nucleophilic silicon and tin. Conjugate addition, allylic substitution, and carbon--carbon multiple bond functionalization is now catalytic in copper!

  16. Effects of heat treatment on wear behavior of carbon/carbon-copper composites under electrical current%热处理对炭/炭-铜复合材料载流磨损行为的影响

    Institute of Scientific and Technical Information of China (English)

    杨鹏翱; 张红波; 尹健; 杨双磊

    2015-01-01

    To explore the effects of heat treatment of Carbon/Carbon ( C/C ) substrates on wear behavior of Carbon/Carbon⁃Copper ( C/C-Cu) composites, copper⁃impregnated carbon fiber reinforced carbon composites were fabricated by infiltrating molten copper alloy into C/C substrates, which were made by chemical vapor infiltration ( CVI) . The wear behavior of C/C-Cu composites was investigated by using a dynamic wear test apparatus during application of an AC electrical current. The worn surfaces of composites before and after test were observed by 3D microscope and SEM. Effects of 2 000℃ heat treatment of C/C substrates on wear behavior of C/C-Cu composites were investigated. The results indicate that the mass wear rate and linear wear rate of the C/C-Cu composites whose C/C substrates were treated at 2 000 ℃ were 34. 42% and 17. 84%, respectively, lower than that of composites without heat treatment. The graphitization degree of C/C substrates improved after 2 000 ℃ heat treatment, thus, the interlaminar splitting resistance was reduced. Thus it is easier for graphite sheets to split into small graphite scraps and form a smooth and lubricant film on the surface, which restrained the inhomogeneous wear induced by surface defects. Therefore, the mutual effects of abrasive wear, adhesive wear, oxidation wear and arc ablation are weakened.%为探明炭/炭( C/C)多孔体热处理对炭/炭-铜( C/C-Cu)复合材料载流磨损行为的影响,采用化学气相渗透法( CVI)增密的C/C多孔体,再通过压力熔渗法制备C/C-Cu复合材料.采用载流动态磨损试验机测试C/C-Cu复合材料载流磨损行为,利用数字式三维视频显微镜和扫描电子显微镜观察复合材料磨损前后的表面形貌,研究了C/C多孔体经过2000℃热处理对C/C-Cu复合材料载流磨损行为的影响.结果表明:C/C-Cu复合材料的质量磨损率和线磨损率比C/C多孔体未经热处理

  17. 云南某高碳低铜碳质银矿综合回收试验研究%Experimental Research on Comprehensive Recovery of a High-Carbon Low-Copper Carbonaceous Silver Ore in Yunnan

    Institute of Scientific and Technical Information of China (English)

    彭远伦

    2012-01-01

    Aiming at the problem that a high-carbon low-copper carbonaceous silver mineral in Yunnan can not be recovered with cyanidation due to its high-carbon content, by conducting notation test research, optimization of flotation principle process on " two roughing, two scavenging and three cleaning", regrinding of primary concentrate, and using carbonaceous gangue depressant, the experimental results that the recoveries of silver and copper are 63. 58% and 62. 93% respectively have been obtained to recover comprehensively silver and copper in the mentioned ore.%针对云南某高碳低铜碳质银矿因含碳高,无法氰化浸出回收的问题.通过浮选试验研究,优选“两粗两扫三精”浮选原则流程,再辅以粗精矿再磨、碳质脉石抑制剂的使用等措施,取得浮选银回收率63.58%、铜回收率62.93%的试验结果,达到综合回收该类矿物铜、银资源的目的.

  18. Impact of pH, dissolved inorganic carbon, and polyphosphates for the initial stages of water corrosion of copper surfaces investigated by AFM and NEXAFS

    Science.gov (United States)

    Nanoscale studies at the early stages of the exposure of copper surfaces after systematic treatments in synthesized water solutions can provide useful information about corrosion processes. The corrosion and passivation of copper surfaces as influenced by pH, dissolved inorganic ...

  19. Synthesis of subnanometer-diameter vertically aligned single-walled carbon nanotubes with copper-anchored cobalt catalysts

    Science.gov (United States)

    Cui, Kehang; Kumamoto, Akihito; Xiang, Rong; An, Hua; Wang, Benjamin; Inoue, Taiki; Chiashi, Shohei; Ikuhara, Yuichi; Maruyama, Shigeo

    2016-01-01

    We synthesize vertically aligned single-walled carbon nanotubes (VA-SWNTs) with subnanometer diameters on quartz (and SiO2/Si) substrates by alcohol CVD using Cu-anchored Co catalysts. The uniform VA-SWNTs with a nanotube diameter of 1 nm are synthesized at a CVD temperature of 800 °C and have a thickness of several tens of μm. The diameter of SWNTs was reduced to 0.75 nm at 650 °C with the G/D ratio maintained above 24. Scanning transmission electron microscopy energy-dispersive X-ray spectroscopy (EDS-STEM) and high angle annular dark field (HAADF-STEM) imaging of the Co/Cu bimetallic catalyst system showed that Co catalysts were captured and anchored by adjacent Cu nanoparticles, and thus were prevented from coalescing into a larger size, which contributed to the small diameter of SWNTs. The correlation between the catalyst size and the SWNT diameter was experimentally clarified. The subnanometer-diameter and high-quality SWNTs are expected to pave the way to replace silicon for next-generation optoelectronic and photovoltaic devices.We synthesize vertically aligned single-walled carbon nanotubes (VA-SWNTs) with subnanometer diameters on quartz (and SiO2/Si) substrates by alcohol CVD using Cu-anchored Co catalysts. The uniform VA-SWNTs with a nanotube diameter of 1 nm are synthesized at a CVD temperature of 800 °C and have a thickness of several tens of μm. The diameter of SWNTs was reduced to 0.75 nm at 650 °C with the G/D ratio maintained above 24. Scanning transmission electron microscopy energy-dispersive X-ray spectroscopy (EDS-STEM) and high angle annular dark field (HAADF-STEM) imaging of the Co/Cu bimetallic catalyst system showed that Co catalysts were captured and anchored by adjacent Cu nanoparticles, and thus were prevented from coalescing into a larger size, which contributed to the small diameter of SWNTs. The correlation between the catalyst size and the SWNT diameter was experimentally clarified. The subnanometer-diameter and high

  20. Controllable Synthesis of Copper Oxide/Carbon Core/Shell Nanowire Arrays and Their Application for Electrochemical Energy Storage

    Science.gov (United States)

    Zhan, Jiye; Chen, Minghua; Xia, Xinhui

    2015-01-01

    Rational design/fabrication of integrated porous metal oxide arrays is critical for the construction of advanced electrochemical devices. Herein, we report self-supported CuO/C core/shell nanowire arrays prepared by the combination of electro-deposition and chemical vapor deposition methods. CuO/C nanowires with diameters of ~400 nm grow quasi-vertically to the substrates forming three-dimensional arrays architecture. A thin carbon shell is uniformly coated on the CuO nanowire cores. As an anode of lithium ion batteries, the resultant CuO/C nanowire arrays are demonstrated to have high specific capacity (672 mAh·g−1 at 0.2 C) and good cycle stability (425 mAh·g−1 at 1 C up to 150 cycles). The core/shell arrays structure plays positive roles in the enhancement of Li ion storage due to fast ion/electron transfer path, good strain accommodation and sufficient contact between electrolyte and active materials.

  1. Effect of copper ion on adsorption of chlorinated phenols and 1-naphthylamine to surface-modified carbon nanotubes.

    Science.gov (United States)

    Wang, Fang; Zhu, Dongqiang; Chen, Wei

    2012-01-01

    Understanding the adsorptive interactions between organic contaminants and carbon nanotubes (CNTs) is critical to both environmental applications and risk management of CNTs. The objective of the present study was to understand how transitional metal ions with strong complexing capabilities might affect the adsorption of hydroxyl- and amino-substituted aromatics to surface O-functionality-rich single-walled CNTs (O-SWNT) and N-functionality-rich single-walled CNTs (N-SWNT). Adsorption of 2,4-dichlorophenol, pentachlorophenol, and 1-naphthylamine to O-SWNT and N-SWNT can be significantly enhanced in the presence of Cu(II) (50 mg/L), whereas adsorption of 1,2-dichlorobenzene is essentially unaffected. The most likely mechanism for the Cu-enhanced adsorption is that Cu(II) serves as a bridging agent between organic solutes and the functional groups on CNT surfaces. For the adsorption of 1-naphthylamine to N-SWNT, an additional mechanism might be possible; that is, the complexation of Cu(II) with the N-functional groups of N-SWNT can change these groups from strong Lewis bases to Lewis acids and thereby significantly enhance adsorption via the mechanism of Lewis acid-base interactions. In addition, adsorption of Cu(II) can be significantly enhanced by the adsorption of organic cosolutes.

  2. Simultaneous ultrasound-assisted ternary adsorption of dyes onto copper-doped zinc sulfide nanoparticles loaded on activated carbon: Optimization by response surface methodology

    Science.gov (United States)

    Asfaram, Arash; Ghaedi, Mehrorang; Hajati, Shaaker; Goudarzi, Alireza; Bazrafshan, Ali Akbar

    2015-06-01

    The simultaneous and competitive ultrasound-assisted removal of Auramine-O (AO), Erythrosine (Er) and Methylene Blue (MB) from aqueous solutions were rapidly performed onto copper-doped zinc sulfide nanoparticles loaded on activated carbon (ZnS:Cu-NP-AC). ZnS:Cu nanoparticles were studied by FESEM, XRD and TEM. First, the effect of pH was optimized in a one-at-a-time procedure. Then the dependency of dyes removal percentage in their ternary solution on the level and magnitude of variables such as sonication time, initial dyes concentrations and adsorbent dosage was fully investigated and optimized by central composite design (CCD) under response surface methodology (RSM) as well as by regarding desirability function (DF) as a good and general criterion. The good agreement found between experimental and predicted values supports and confirms the suitability of the present model to predict adsorption state. The applied ultrasound strongly enhanced mass transfer process and subsequently performance. Hence, a small amount of the adsorbent (0.04 g) was capable to remove high percentage of dyes, i.e. 100%, 99.6% and 100% for MB, AO and Er, respectively, in very short time (2.5 min). The experimental equilibrium data fitting to Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models showed that the Langmuir model applies well for the evaluation and description of the actual behavior of adsorption. The small amount of proposed adsorbent (0.015 g) was applicable for successful removal of dyes (RE > 99.0%) in short time (2.5 min) with high adsorption capacity in single component system (123.5 mg g-1 for MB, 123 mg g-1 for AO and 84.5 mg g-1 for Er). Kinetics evaluation of experiments at various time intervals reveals that adsorption processes can be well predicated and fitted by pseudo-second-order and Elovich models.

  3. Isotherm and kinetics study of malachite green adsorption onto copper nanowires loaded on activated carbon: Artificial neural network modeling and genetic algorithm optimization

    Science.gov (United States)

    Ghaedi, M.; Shojaeipour, E.; Ghaedi, A. M.; Sahraei, Reza

    2015-05-01

    In this study, copper nanowires loaded on activated carbon (Cu-NWs-AC) was used as novel efficient adsorbent for the removal of malachite green (MG) from aqueous solution. This new material was synthesized through simple protocol and its surface properties such as surface area, pore volume and functional groups were characterized with different techniques such XRD, BET and FESEM analysis. The relation between removal percentages with variables such as solution pH, adsorbent dosage (0.005, 0.01, 0.015, 0.02 and 0.1 g), contact time (1-40 min) and initial MG concentration (5, 10, 20, 70 and 100 mg/L) was investigated and optimized. A three-layer artificial neural network (ANN) model was utilized to predict the malachite green dye removal (%) by Cu-NWs-AC following conduction of 248 experiments. When the training of the ANN was performed, the parameters of ANN model were as follows: linear transfer function (purelin) at output layer, Levenberg-Marquardt algorithm (LMA), and a tangent sigmoid transfer function (tansig) at the hidden layer with 11 neurons. The minimum mean squared error (MSE) of 0.0017 and coefficient of determination (R2) of 0.9658 were found for prediction and modeling of dye removal using testing data set. A good agreement between experimental data and predicted data using the ANN model was obtained. Fitting the experimental data on previously optimized condition confirm the suitability of Langmuir isotherm models for their explanation with maximum adsorption capacity of 434.8 mg/g at 25 °C. Kinetic studies at various adsorbent mass and initial MG concentration show that the MG maximum removal percentage was achieved within 20 min. The adsorption of MG follows the pseudo-second-order with a combination of intraparticle diffusion model.

  4. Influence of dissolved organic carbon on toxicity of copper to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) in acute and chronic water exposures.

    Science.gov (United States)

    Wang, Ning; Mebane, Christopher A; Kunz, James L; Ingersoll, Christopher G; Brumbaugh, William G; Santore, Robert C; Gorsuch, Joseph W; Arnold, W Ray

    2011-09-01

    Acute and chronic toxicity of copper (Cu) to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) were determined in water exposures at four concentrations of dissolved organic carbon (DOC; nominally 0.5, 2.5, 5, and 10 mg/L as carbon [C]). Test waters with DOC concentrations of 2.5 to 10 mg C/L were prepared by mixing a concentrate of natural organic matter (Suwannee River, GA, USA) in diluted well water (hardness 100 mg/L as CaCO(3) , pH 8.3, DOC 0.5 mg C/L). Acute median effect concentrations (EC50s) for dissolved Cu increased approximately fivefold (15-72 µg Cu/L) for mussel survival in 4-d exposures and increased about 11-fold (25-267 µg Cu/L) for cladoceran survival in 2-d exposures across DOC concentrations from 0.5 to 10 mg C/L. Similarly, chronic 20% effect concentrations (EC20s) for the mussel in 28-d exposures increased about fivefold (13-61 µg Cu/L for survival; 8.8-38 µg Cu/L for biomass), and the EC20s for the cladoceran in 7-d exposures increased approximately 17-fold (13-215 µg Cu/L) for survival or approximately fourfold (12-42 µg Cu/L) for reproduction across DOC concentrations from 0.5 to 10 mg C/L. The acute and chronic values for the mussel were less than or approximately equal to the values for the cladoceran. Predictions from the biotic ligand model (BLM) used to derive the U.S. Environmental Protection Agency's ambient water quality criteria (AWQC) for Cu explained more than 90% of the variation in the acute and chronic endpoints for the two species, with the exception of the EC20 for cladoceran reproduction (only 46% of variation explained). The BLM-normalized acute EC50s and chronic EC20s for the mussel and BLM-normalized chronic EC20s for the cladoceran in waters with DOC concentrations of 2.5 to 10 mg C/L were equal to or less than the final acute value and final chronic value in the BLM-based AWQC for Cu, respectively, indicating that the Cu AWQC might not adequately protect the mussel from acute and

  5. Influence of Test Parameters on Performances of Carbon Fiber-Copper Composite%试验参数对碳纤维铜复合材料性能的影响

    Institute of Scientific and Technical Information of China (English)

    钟涛生; 李小红; 付求涯; 方晶

    2015-01-01

    Effect of pressure,time and way of pressing,sintering temperature and copper plating time of carbon fibre on performances of a carbon fiber-copper composite was investigated by using raw materials such as copper sulfate,carbon fiber,copper powder and other reagents.The results are that:(a)as the pressing pressure becomes higher and the pressing time become longer both the density and the collapsing strength of the composite billet are increased first fast then slow;(b)the two-direction pressed billet is superior to the one-direction pressed billet in the performances;(c)the density,strength and wearability of the composite increase with the elevation of sintering temperature,and when the temperature is above 750 ~800 ℃,the strength decreases,while the density and the wearability remain constant;(d)the prolongation of copper plating time will allow the strength and dry frictional behavior to increase rapidly and then to remain constant,but have no effect on the density and lubrication friction behavior.%以硫酸铜、碳纤维、铜粉等试剂作为原材料,研究了压制的压力、时间和方式,烧结温度及碳纤维镀铜时间等因素对碳纤维铜复合材料性能的影响。结果表明,随着压制压力的升高和压制时间的延长,复合材料坯体的密度和压溃强度都先快速后缓慢增加;双向压制坯体的性能优于单向压制坯体;复合材料的密度、强度和耐磨性能随着烧结温度的上升而提高,高于750~800℃时,强度开始下降,密度和抗磨性能保持不变;随着镀铜时间的延长,强度和干摩擦性能先快速提高,而后维持不变,但不影响密度和润滑摩擦性能。

  6. Microwaves initiated synthesis of activated carbon-based composite hydrogel for simultaneous removal of copper(II) ions and direct red 80 dye: A multi-component adsorption system

    OpenAIRE

    Oladipo, Akeem Adeyemi; Gazi, Mustafa

    2015-01-01

    We present a novel microwave initiated preparation of polyacrylamide/activated carbon hydrogel (PAAm-FAc) in this article and characterized by FT-IR, pHzpc and Boehm titration. The adsorbent was assessed for competitive adsorption of copper(II) and direct red 80 from a binary mixture in a single-staged batch process as a function of volume of binary mixture/mass of adsorbent (V0/M0) ratio at varying orders of second pollutant concentration. A competitive, multi-component Langmuir isotherm was...

  7. Carbon nanotube-copper exhibiting metal-like thermal conductivity and silicon-like thermal expansion for efficient cooling of electronics.

    Science.gov (United States)

    Subramaniam, Chandramouli; Yasuda, Yuzuri; Takeya, Satoshi; Ata, Seisuke; Nishizawa, Ayumi; Futaba, Don; Yamada, Takeo; Hata, Kenji

    2014-03-07

    Increasing functional complexity and dimensional compactness of electronic devices have led to progressively higher power dissipation, mainly in the form of heat. Overheating of semiconductor-based electronics has been the primary reason for their failure. Such failures originate at the interface of the heat sink (commonly Cu and Al) and the substrate (silicon) due to the large mismatch in thermal expansion coefficients (∼300%) of metals and silicon. Therefore, the effective cooling of such electronics demands a material with both high thermal conductivity and a similar coefficient of thermal expansion (CTE) to silicon. Addressing this demand, we have developed a carbon nanotube-copper (CNT-Cu) composite with high metallic thermal conductivity (395 W m(-1) K(-1)) and a low, silicon-like CTE (5.0 ppm K(-1)). The thermal conductivity was identical to that of Cu (400 W m(-1) K(-1)) and higher than those of most metals (Ti, Al, Au). Importantly, the CTE mismatch between CNT-Cu and silicon was only ∼10%, meaning an excellent compatibility. The seamless integration of CNTs and Cu was achieved through a unique two-stage electrodeposition approach to create an extensive and continuous interface between the Cu and CNTs. This allowed for thermal contributions from both Cu and CNTs, resulting in high thermal conductivity. Simultaneously, the high volume fraction of CNTs balanced the thermal expansion of Cu, accounting for the low CTE of the CNT-Cu composite. The experimental observations were in good quantitative concurrence with the theoretically described 'matrix-bubble' model. Further, we demonstrated identical in-situ thermal strain behaviour of the CNT-Cu composite to Si-based dielectrics, thereby generating the least interfacial thermal strain. This unique combination of properties places CNT-Cu as an isolated spot in an Ashby map of thermal conductivity and CTE. Finally, the CNT-Cu composite exhibited the greatest stability to temperature as indicated by its low

  8. Square-wave voltammetric determination of rutin in pharmaceutical formulations using a carbon composite electrode modified with copper (II phosphate immobilized in polyester resin

    Directory of Open Access Journals (Sweden)

    Kellen Heloizy Garcia Freitas

    2012-12-01

    Full Text Available A carbon composite electrode modified with copper (II phosphate immobilized in a polyester resin (Cu3(PO42-Poly for the determination of rutin in pharmaceutical samples by square-wave voltammetry is described herein. The modified electrode allows the determination of rutin at a potential (0.20 V vs. Ag/AgCl (3.0 mol L-1 KCl lower than that observed at an unmodified electrode. The peak current was found to be linear to the rutin concentration in the range from 9.9 × 10-8 to 2.5 × 10-6 mol L-1, with a detection limit of 1.2×10-8 mol L-1. The response of the electrode was stable, with no variation in baseline levels within several hours of continuous operation. The surface morphology of the modified electrode was characterized by scanning electron microscopy (SEM and energy dispersive X-ray (EDX system. The results obtained are precise and accurate. In addition, these results are in agreement with those obtained by the chromatographic method at a 95% confidence level.Descreve-se um eletrodo de carbono modificado com fosfato de cobre (II imobilizado em uma resina de poliéster (Cu3(PO42-Poly para a determinação de rutina em amostras farmacêuticas por voltametria de onda quadrada. O eletrodo modificado permite a determinação de rutina em potencial (0.20 V vs Ag / AgCl (3,0 mol L-1 KCl menor que o observado em um eletrodo não modificado. Verificou-se que a corrente de pico foi linear com a concentração de rutina na faixa de 9,9 × 10-8 a 2,5 × 10-6 mol L-1, com um limite de detecção de 1,2 × 10-8 mol L¹. A resposta do eletrodo foi estável, sem variação significativa dentro de várias horas de operação contínua. A morfologia da superfície do eletrodo modificado foi caracterizada por microscopia eletrônica de varredura (MEV e pelo sistema de energia dispersiva de raios-X (EDX. Os resultados obtidos foram precisos e exatos. Ademais, estes resultados estão de acordo com aqueles obtidos pelo método cromatográfico a um nível de

  9. 内嵌碳纳米管铜复合颗粒的制备%Preparation of Copper Composite Particles Inner-Embedded with Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    王伟; 陈小华; 刘云泉; 易斌; 颜海梅

    2011-01-01

    采用混酸纯化法在碳纳米管表面引入羟基、羧基等基团,利用明胶使碳纳米管分散在硫酸铜溶液中,和葡萄糖在碱性条件下还原得到内嵌碳纳米管的氧化亚铜复合颗粒,再利用氢气将其还原成为内嵌碳纳米管的铜复合颗粒,通过SEM和TEM观察复合颗粒的形貌,用XRD分析了复合颗粒的物相.结果表明:制备的内嵌碳纳米管的铜复合颗粒粒径在几百纳米到几微米之间,每个颗粒表面均匀分布毛刺状的碳纳米管;纯化后的碳纳米管在硫酸铜溶液中的分散性有所改善,使复合颗粒的纯净度及碳纳米管在铜颗粒内的分散均匀性较好.%Using purification in a mixed acid, hydroxyl groups and carboxyl groups were introduced on the surface of carbon nanotubes (CNTs). Gelatin was used to disperse CNTs uniformly in the CuSO44 solution. CuO2 composite particles inner-embedded with CNTs (CNTs/CuO2) were obtained through reducing the Cu2+ with glucose in alkaline condition. Then copper composite particles inner-embedded with CNTs (CNTs/Cu) were formed using H2 as reducing agent. The morphology of the composite particles was observed by means of SEM and TEM.Phase analysis for the composite particles was performed using XRD. The results show that the particle size of the CNTs/Cu composites was several hundreds nanometers to several microns. There were burr-like CNTs uniformly distributed on the surface of every particle. The dispersion of the CNTs after purified in CuSO4 solution was improved, which made the purification of the composite particles and the dispersible uniformity of the CNTs in Cu particles better.

  10. Catalytic conversion of carbon dioxide into dimethyl carbonate using reduced copper-cerium oxide catalysts as low as 353 K and 1.3 MPa and the reaction mechanism

    Directory of Open Access Journals (Sweden)

    Seiki eWada

    2013-06-01

    Full Text Available Synthesis of dimethyl carbonate (DMC from CO2 and methanol under milder reaction conditions was performed using reduced cerium oxide catalysts and reduced copper-promoted Ce oxide catalysts. Although the conversion of methanol was low (0.005–0.11% for 2 h of reaction, DMC was synthesized as low as 353 K and at total pressure of as low as 1.3 MPa using reduced Cu–CeO2 catalyst (0.5 wt% of Cu. The apparent activation energy was 120 kJ mol–1 and the DMC synthesis rates were proportional to the partial pressure of CO2. An optimum amount of Cu addition to CeO2 was 0.1 wt% for DMC synthesis under the conditions at 393 K and total pressure of 1.3 MPa for 2 h (conversion of methanol: 0.15% due to the compromise of two effects of Cu: the activation of H2 during reduction prior to the kinetic tests and the block (cover of the surface active site. The reduction effects in H2 were monitored through the reduction of Ce4+ sites to Ce3+ based on the shoulder peak intensity at 5727 eV in the Ce L3-edge X-ray absorption near-edge structure (XANES. The Ce3+ content was 10% for reduced CeO2 catalyst whereas it increased to 15% for reduced Cu–CeO2 catalyst (0.5wt% of Cu. Moreover, the content of reduced Ce3+ sites (10% associated with the surface O vacancy (defect sites decreased to 5% under CO2 at 290 K for reduced Cu–CeO2 catalyst (0.1wt% of Cu. The adsorption step of CO2 on the defect sites might be the key step in DMC synthesis and thus the DMC synthesis rate dependence on the partial pressure of CO2 was proportional. Subsequent H atom subtraction steps from methanol at the neighboring surface Lewis base sites should combine two methoxy species to the adsorbed CO2 to form DMC, water, and restore the surface O vacancy.

  11. Multifunctional Carbon Electromagnetic Materials, Motors, and Actuators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of the proposal is to apply multifunctional carbon electromagnetic materials, including carbon nanotube electrical thread (replaces copper wire) and...

  12. Copper Products Capacity Expansion Stimulate the Copper Consumption

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>The dramatic growth of copper consumption in China can directly be seen from the expansion of copper products capacity.According to sta- tistics,in the past 4 years,the improvement on the balance of trade on copper bar,copper,and copper alloy and copper wire & cable has driven the growth of copper consumption a lot.

  13. Antwerp Copper Plates

    DEFF Research Database (Denmark)

    Wadum, Jørgen

    1999-01-01

    In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes.......In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes....

  14. Copper and copper proteins in Parkinson's disease.

    Science.gov (United States)

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

    2014-01-01

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

  15. Cleavage of carbon-nitrogen bond in 1,3,5-tri-tert-butyl-1,3,5-triazacyclohexane by copper(I) bromide

    Science.gov (United States)

    Khatua, Suman; Majumdar, Amit

    2016-09-01

    Reactions of CuCl, CuCl2 and CuBr2 with 1,3,5-tri-tert-butyl-1,3,5-triazacyclohexane (tBu3tach) resulted in the formation of [(tBu3tach-H)+(CuCl2)] (1), [(tBu3tach)(CuCl2)] (2) and [(tBu3tach-H)+(CuBr2)] (3) respectively. Interestingly, CuBr was found to mediate the cleavage of the C-N bonds of tBu3tach in a vast range of solvents, namely, chloroform, dichloromethane, tetrahydrofuran, acetonitrile and methanol to yield [Cu4Br4(tBuNCH2)4] (4) and stands as an example of C-N bond cleavage of 1,3,5-triazacyclohexane rings by copper salts. Compounds 1 and 3 contains amidinium cations and are unstable in solution towards the release of copper. The release of copper from 3 in solution was confirmed by the isolation of the compound, [CuBr(MeCN)] (5). Formation of the amidinium cations [(tBu3tach-H)+] in 1 and 3 may be avoided by the use of PPh3 to yield [(tBu3tach)Cu(PPh3)](PF6) (6), while the coordinated N-tert-butylmethanimine (tBuNCH2) in 4 could be replaced by PPh3 to yield [Cu4Br4(PPh3)4] (7). Complexes 1-7 are characterized by a combination of single crystal X-ray structure determination and/or elemental analysis, NMR, IR, and UV-Vis spectroscopy, and Mass spectrometry.

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  17. Activation of Carbon-Hydrogen and Hydrogen-Hydrogen Bonds by Copper-Nitrenes: A Comparison of Density Functional Theory with Single- and Multireference Correlation Consistent Composite Approaches.

    Science.gov (United States)

    Tekarli, Sammer M; Williams, T Gavin; Cundari, Thomas R

    2009-11-10

    The kinetics and thermodynamics of copper-mediated nitrene insertion into C-H and H-H bonds (the former of methane) have been studied using several levels of theory: B3LYP/6-311++G(d,p), B97-1/cc-pVTZ, PBE1KCIS/cc-pVTZ, and ccCA (correlation consistent Composite Approach). The results show no significant difference among the DFT methods. All three DFT methods predict the ground state of the copper-nitrene model complex, L'Cu(NH), to be a triplet, while single reference ccCA predicts the singlet to be the ground state. The contributions to the total ccCA energy indicate that the singlet state is favored at the MP2/CBS level of theory, while electron correlation beyond this level (CCSD(T)) favors a triplet state, resulting in a close energetic balance between the two states. A multireference ccCA method is applied to the nitrene active species and supports the assignment of a singlet ground state. In general, the largest difference in the model reaction cycles between DFT and ccCA methods is for processes involving radicals and bond dissociation.

  18. Being two is better than one-catalytic reductions with dendrimer encapsulated copper- and copper-cobalt-subnanoparticles.

    Science.gov (United States)

    Ficker, Mario; Petersen, Johannes F; Gschneidtner, Tina; Rasmussen, Ann-Louise; Purdy, Trevor; Hansen, Jon S; Hansen, Thomas H; Husted, Søren; Moth Poulsen, Kasper; Olsson, Eva; Christensen, Jørn B

    2015-06-21

    Copper and copper-cobalt subnanoparticles have been synthesized using 4-carbomethoxypyrrolidone terminated PAMAM-dendrimers as templates. The metal particles were applied in catalytic reduction reactions. While Cu subnanoparticles were only capable of reducing conjugated double bonds, enhancing the Cu particles with Co led to a surprising increase in catalytic activity, reducing also isolated carbon double and triple bonds.

  19. Pesticidal copper (I) oxide: environmental fate and aquatic toxicity.

    Science.gov (United States)

    Kiaune, Lina; Singhasemanon, Nan

    2011-01-01

    reversibility of sensory function effects. The fish olfactory system may be the most sensitive structure to copper pollution. The major factors that influence copper-induced toxicity are dissolved organic carbon and water salinity. Dissolved organic carbon reduces copper toxicity by sequestering bioavailable copper and forming organic complexes with it. Salinity, on the other hand, influences copper bioavailability at the biological action site and also affects metal biodistribution and bioaccumulation in the organism. Therefore, the salinity gradient can increase or decrease copper toxicity in different aquatic species. In some killifish, copper may affect different organs at different times, depending on the water salinity. The most studied and best explained copper toxicity mechanisms involve inhibition of key enzymes and disruption of osmoregulation in the gill. Other toxicity mechanisms may involve reactive oxygen species generation and changes of gene transcription in the fish olfactory signaling pathway. More studies are needed to evaluate the potential magnitude of copper remobilization from the sediment that may result from climate change and its effects on surface waters. Moreover, the environmental exposure, fate, and ecotoxicity of emerging metal nanoparticles, including nanocopper, will require additional studies as new forms of copper appear from application of nanotechnology to copper compounds.

  20. Preparation of graphite dispersed copper composite with intruding graphite particles in copper plate

    Science.gov (United States)

    Noor, Abdul Muizz Mohd; Ishikawa, Yoshikazu; Yokoyama, Seiji

    2017-01-01

    In this study, it was attempted that copper-graphite composite was prepared locally on the surface of a copper plate with using a spot welding machine. Experiments were carried out with changing the compressive load, the repetition number of the compression and the electrical current in order to study the effect of them on carbon content and Vickers hardness on the copper plate surface. When the graphite was pushed into copper plate only with the compressive load, the composite was mainly hardened by the work hardening. The Vickers hardness increased linearly with an increase in the carbon content. When an electrical current was energized through the composite at the compression, the copper around the graphite particles were heated to the temperature above approximately 2100 K and melted. The graphite particles partially or entirely dissolved into the melt. The graphite particles were precipitated from the melt under solidification. In addition, this high temperature caused the improvement of wetting of copper to graphite. This high temperature caused the annealing, and reduced the Vickers hardness. Even in this case, the Vickers hardness increased with an increase in the carbon content. This resulted from the dispersion hardening.

  1. Recovery of Iron from Copper Tailings by Direct Reduction

    Science.gov (United States)

    Gu, Jing; Xia, De-Hong; Gu, Jing; Liu, Kai-Qi; Zhang, Feng; Wang, Shou-Zeng; Qi, Zhao-Dong; Ao, Wen-Qing

    2016-05-01

    Direct reduction of copper tailings were performed to recover iron efficiently by carbon-containing pellets, and the metallization rate was gained by chemical analysis method. The results showed that the metallization rate of copper tailings was up to 85.32% and the best reduction parameters are also found. Content of precious metals, such as, gold, silver in copper tailings can be enriched by 1.8~1.9 times through removing iron. The apparent activation energy of direct reduction of iron oxide in copper tailings is calculated to be 125.4 kJ/mol and the restrictive factor of reduction process is solid diffusion.

  2. Carbon monoxide binding to the heme group at the dimeric interface modulates structure and copper accessibility in the Cu,Zn superoxide dismutase from Haemophilus ducreyi: in silico and in vitro evidences.

    Science.gov (United States)

    Chillemi, Giovanni; De Santis, Serena; Falconi, Mattia; Mancini, Giordano; Migliorati, Valentina; Battistoni, Andrea; Pacello, Francesca; Desideri, Alessandro; D'Angelo, Paola

    2012-01-01

    X-ray absorption near-edge structure (XANES) spectroscopy and molecular dynamics (MD) simulations have been jointly applied to the study of the Cu,Zn superoxide dismutase from Haemophilus ducreyi (HdSOD) in interaction with the carbon monoxide molecule. The configurational flexibility of the Fe(II)-heme group, intercalated between the two subunits, has been sampled by MD simulations and included in the XANES data analysis without optimization in the structural parameter space. Our results provide an interpretation of the observed discrepancy in the Fe-heme distances as detected by extended X-ray absorption fine structure (EXAFS) spectroscopy and the classical XANES analysis, in which the structural parameters are optimized in a unique structure. Moreover, binding of the CO molecule to the heme induces a long range effect on the Cu,Zn active site, as evidenced by both MD simulations and in vitro experiments. MD simulation of the CO bound system, in fact, highlighted a structural rearrangement of the protein-protein hydrogen bond network in the region of the Cu,Zn active site, correlated with an increase in water accessibility at short distance from the copper atom. In line, in vitro experiments evidenced an increase of copper accessibility to a chelating agent when the CO molecule binds to the heme group, as compared to a heme deprived HdSOD. Altogether, our results support the hypothesis that the HdSOD is a heme-sensor protein, in which binding to small gaseous molecules modulates the enzyme superoxide activity as an adaptive response to the bacterial environment.

  3. Structural and Biochemical Characterization of a Copper-Binding Mutant of the Organomercurial Lyase MerB: Insight into the Key Role of the Active Site Aspartic Acid in Hg-Carbon Bond Cleavage and Metal Binding Specificity.

    Science.gov (United States)

    Wahba, Haytham M; Lecoq, Lauriane; Stevenson, Michael; Mansour, Ahmed; Cappadocia, Laurent; Lafrance-Vanasse, Julien; Wilkinson, Kevin J; Sygusch, Jurgen; Wilcox, Dean E; Omichinski, James G

    2016-02-23

    In bacterial resistance to mercury, the organomercurial lyase (MerB) plays a key role in the detoxification pathway through its ability to cleave Hg-carbon bonds. Two cysteines (C96 and C159; Escherichia coli MerB numbering) and an aspartic acid (D99) have been identified as the key catalytic residues, and these three residues are conserved in all but four known MerB variants, where the aspartic acid is replaced with a serine. To understand the role of the active site serine, we characterized the structure and metal binding properties of an E. coli MerB mutant with a serine substituted for D99 (MerB D99S) as well as one of the native MerB variants containing a serine residue in the active site (Bacillus megaterium MerB2). Surprisingly, the MerB D99S protein copurified with a bound metal that was determined to be Cu(II) from UV-vis absorption, inductively coupled plasma mass spectrometry, nuclear magnetic resonance, and electron paramagnetic resonance studies. X-ray structural studies revealed that the Cu(II) is bound to the active site cysteine residues of MerB D99S, but that it is displaced following the addition of either an organomercurial substrate or an ionic mercury product. In contrast, the B. megaterium MerB2 protein does not copurify with copper, but the structure of the B. megaterium MerB2-Hg complex is highly similar to the structure of the MerB D99S-Hg complexes. These results demonstrate that the active site aspartic acid is crucial for both the enzymatic activity and metal binding specificity of MerB proteins and suggest a possible functional relationship between MerB and its only known structural homologue, the copper-binding protein NosL.

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

    Science.gov (United States)

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

    2005-09-01

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

  5. Synthesis, Characterization and Photoelectric Properties of the Copper Phthalocyanine-modied Multi-walled Carbon Nanotubes%多壁碳纳米管-酞菁铜复合物的合成表征及光电性能

    Institute of Scientific and Technical Information of China (English)

    吴振奕; 杨绳岩

    2011-01-01

    采用氯磺酸作为磺化试剂,在多壁碳纳米管上接枝氯磺酰基,之后通过乙二胺的胺解反应,制备出胺基修饰的多壁碳纳米管MWCNT-NH2,并进一步与氯磺酰基酞菁铜反应制备出MWCNT-Pc复合物.产物采用红外光谱,紫外可见,拉曼光谱,X射线光电子能谱,循环伏安,热重分析等进行了表征.结果表明,MWCNT-NH2上磺酰胺基接枝在MWCNT表面,而MWCNT-Pc上的酞菁基团是通过MWCNT-NH2上的酰胺基团与Pc形成复合物,碳纳米管上约38个碳原子结合一个磺酸基酞菁分子;该MWCNT-Pc复合物的热稳定性较MWCNT-NH2低;利用喷涂法构筑了ITO/MWCNT-Pc光电极,光电性能的研究结果表明在AM1.5光照条件下,光电压及光电流分别为0.434V和0.158mA/cm2;在320nm处的IPCE达19.8%,具有较优良的光电转化性能.根据测得的MWCNT-Pc的能带结构,推知MWCNT-Pc的光诱导电子转移过程是Pc端基发生光激发电子跃迁,此后电子转移到MWCNTs上并进一步传递到ITO,完成电荷分离.%Multi-walled carbon nanotubes (MWCNTs) were grafted with sulfonyl chloride groups using chlorosulfonic acid as a sulfonation reagent, and then the amino-modified multi-walled carbon nanotubes of MWCNT-NH2 was prepared via the aminolysis reaction. The MWCNT-NH2 was further reacted with copper phthalocyanine sulfonyl chloride to prepared the complex of MWCNT-Pc. The products were fully characterized by various standard analytical techniques, including scanning electron microscope, transmission electron microscope, infrared spectroscope, UV-Vis absorption spectroscope, Raman spectroscope, X-ray photoelectron spectroscope, thermogravimetric analysis, and cyclic voltammetry. The results indicated that the complex of MWCNT-Pc was fabricated through covalent assembly of MWCNT-NH2 with copper phthalocyanine, with a copper phthalocyanine molecule for every 38 MWCNT carbons.The thermal stability of the complex of MWCNT-Pc was lower than that of MWCNT-NH2.The

  6. Synthesis of copper nanoparticles in polycarbonate by ion implantation

    Indian Academy of Sciences (India)

    Annu Sharma; Suman Bahniwal; Sanjeev Aggarwal; S Chopra; D Kanjilal

    2011-07-01

    Copper nanoparticles have been synthesized in polycarbonate by 75 KeV Cu– ion implantation with various doses ranging from 6.4 × 1015 to 1.6 × 1017 ions/cm2 with a beam current density of 800 nA/cm2. The composites formed were structurally characterized using Ultraviolet-Visible (UV-Visible) absorption spectroscopy. The appearance of particle plasmon resonance peak, characteristic of copper nanoparticles at 603 nm in absorption spectra of polycarbonate implanted to a dose of 1.6 × 1017 ions/cm2, indicates towards the formation of copper nanoparticles in polycarbonate. Transmission electron microscopy further confirms the formation of copper nanoparticles having size ∼ 3.15 nm. The formation of copper nanoparticles in the layers carbonized by Cu– implantation has been discussed. The synthesized copper-polycarbonate nanocomposite has been found to be more conducting than polycarbonate as ascertained using current–voltage characteristics.

  7. Carbonic Anhydrase II: A Model System for Artificial Copper Center Design, Protein-guided Cycloadditions, Tethering Screenings and Fragment-based Lead Discovery

    OpenAIRE

    Schulze Wischeler, Johannes

    2010-01-01

    In this thesis a variety of quite different fragment-based lead discovery approaches have been applied to the target protein carbonic anhydrase II. The different projects were strongly supported and methodologically tailored towards protein crystallography; a method which is currently emerging as a routine analytical tool. This maturation mainly results from improved radiation sources and enhanced computing power. About 200-250 da...

  8. Surface films and corrosion of copper

    Energy Technology Data Exchange (ETDEWEB)

    Hilden, J.; Laitinen, T.; Maekelae, K.; Saario, T.; Bojinov, M. [VTT Manufacturing Technology, Espoo (Finland)

    1999-03-01

    In Sweden and Finland the spent nuclear fuel is planned to be encapsulated in cast iron canisters that have an outer shield made of copper. The copper shield is responsible for the corrosion protection of the canister construction. General corrosion of the copper is not expected to be the limiting factor in the waste repository environment when estimating the life-time of the canister construction. However, different forms of localised corrosion, i.e. pitting, stress corrosion cracking, or environmentally assisted creep fracture may cause premature failure of the copper shield. Of the probable constituents in the groundwater, nitrites, chlorides, sulphides and carbonates have been suggested to promote localised corrosion of copper. The main assumption made in planning this research program is that the surface films forming on copper in the repository environment largely determine the susceptibility of copper to the different forms of localised corrosion. The availability of reactants, which also may become corrosion rate limiting, is investigated in several other research programs. This research program consists of a set of successive projects targeted at characterising the properties of surface films on copper in repository environment containing different detrimental anions. A further aim was to assess the significance of the anion-induced changes in the stability of the oxide films with regard to localised corrosion of copper. This report summarises the results from a series of investigations on properties of surface films forming on copper in water of pH = 8.9 at temperature of 80 deg C and pressure of 2 MPa. The main results gained so far in this research program are as follows: The surface films forming on copper in the thermodynamic stability region of monovalent copper at 80 deg C consist of a bulk part (about 1 mm thick) which is a good ionic and electronic conductor, and an outer, interfacial layer (0.001 - 0.005 mm thick) which shows p-type semiconductor

  9. [Copper pathology (author's transl)].

    Science.gov (United States)

    Mallet, B; Romette, J; Di Costanzo, J D

    1982-01-30

    Copper is an essential dietary component, being the coenzyme of many enzymes with oxidase activity, e.g. ceruloplasmin, superoxide dismutase, monoamine oxidase, etc. The metabolism of copper is complex and imperfectly known. Active transport of copper through the intestinal epithelial cells involves metallothionein, a protein rich in sulfhydryl groups which also binds the copper in excess and probably prevents absorption in toxic amounts. In hepatocytes a metallothionein facilitates absorption by a similar mechanism and regulates copper distribution in the liver: incorporation in an apoceruloplasmin, storage and synthesis of copper-dependent enzymes. Metallothioneins and ceruloplasmin are essential to adequate copper homeostasis. Apart from genetic disorders, diseases involving copper usually result from hypercupraemia of varied origin. Wilson's disease and Menkes' disease, although clinically and pathogenetically different, are both marked by low ceruloplasmin and copper serum levels. The excessive liver retention of copper in Wilson's disease might be due to increased avidity of hepatic metallothioneins for copper and decreased biliary excretion through lysosomal dysfunction. Menkes' disease might be due to low avidity of intestinal and hepatic metallothioneins for copper. The basic biochemical defect responsible for these two hereditary conditions has not yet been fully elucidated.

  10. [Copper IUDs (author's transl)].

    Science.gov (United States)

    Thiery, M

    1983-10-01

    Following initial development of the Grafenberg ring in the 1920's, IUDs fell into disuse until the late 1950s, when plastic devices inserted using new technology began to gain worldwide acceptance. Further research indicated that copper had a significant antifertility effect which increased with increasing surface area, and several copper IUDs were developed and adapted, including the Copper T 200, the Copper T 220C, and the Copper T 380 A, probably the most effective yet. The Gravigard and Multiload are 2 other copper devices developed according to somewhat different principles. Copper devices are widely used not so much because of their great effectiveness as because of their suitability for nulliparous patients and their ease of insertion, which minimizes risk of uterine perforation. Records of 2584 women using Copper IUDs for 7190 women-years and 956 women using devices without copper for 6059 women-years suggest that the copper devices were associated with greater effectiveness and fewer removals for complications. Research suggests that the advantages of copper IUDs become more significant with increased duration of use. Contraindications to copper devices include allergy to copper and hepatolenticular degeneration. No carcinogenic or teratogenic effect of copper devices has been found, but further studies are needed to rule out other undesirable effects. Significant modifications of copper devices in recent years have been developed to increase their effectiveness, prolong their duration of usefulness, facilitate insertion and permit insertion during abortion or delivery. The upper limit of the surface area of copper associated with increased effectiveness appears to be between 200-300 sq mm, and at some point increases in copper exposure may provoke expulsion of the IUD. The duration of fertility inhibition of copper IUDs is usually estimated at 2-3 years, but recent research indicates that it may be 6-8 years, and some devices may retain copper surface

  11. The changes in the chloroplast membranes of pea leaves under the influence of carbonic anhydrase inhibitors (ions of copper and zinc

    Directory of Open Access Journals (Sweden)

    M.V. Vodka

    2014-04-01

    Full Text Available Тhe effects of carbonic anhydrase inhibitors, such as ions Cu2+ and Zn2+, on the membrane system of chloroplasts in pea leaves were investigated. After treatment of pea leaves with 250 mM Cu2+ or 400 mM Zn2+ we observed changes in the granal structure and compactness of the thylakoids in granae. It was shown that the thickness of granal thylakoids and the interspace between thylakoids increased comparing to control. Changes of the size and structure of thylakoids and granae in treated leaves may be associated with the enhanced accumulation of CO2 in the membrane. It is suggested that the carbonic anhydrase may also play a structural role in chloroplast granae.

  12. Fixation of CO2 by electrocatalytic reduction to synthesis of dimethyl carbonate in ionic liquid using effective silver-coated nanoporous copper composites

    Institute of Scientific and Technical Information of China (English)

    Xuan Yun Wang; Su Qin Liu; Ke Long Huang; Qiu Ju Feng; De Lai Ye; Bing Liu; Jin Long Liu; Guan Hua Jin

    2010-01-01

    With high surface area, open porosity and high efficiency, a catalyst was prepared and firstly employed in electrocatalytic reduction of CO2 and electrosynthesis of dimethyl carbonate (DMC). The electrochemical property for electrocatalytic reduction of CO2 in ionic liquid was studied by cyclic voitammogram (CV). The effects of various reaction variables like temperature, working potential and cathode materials on the electrocatalytic performance were also investigated. 80% yield of DMC was obtained under the optimal reaction conditions.

  13. Wiring-up carbon single wall nanotubes to polycrystalline inorganic semiconductor thin films: low-barrier, copper-free back contact to CdTe solar cells.

    Science.gov (United States)

    Phillips, Adam B; Khanal, Rajendra R; Song, Zhaoning; Zartman, Rosa M; DeWitt, Jonathan L; Stone, Jon M; Roland, Paul J; Plotnikov, Victor V; Carter, Chad W; Stayancho, John M; Ellingson, Randall J; Compaan, Alvin D; Heben, Michael J

    2013-11-13

    We have discovered that films of carbon single wall nanotubes (SWNTs) make excellent back contacts to CdTe devices without any modification to the CdTe surface. Efficiencies of SWNT-contacted devices are slightly higher than otherwise identical devices formed with standard Au/Cu back contacts. The SWNT layer is thermally stable and easily applied with a spray process, and SWNT-contacted devices show no signs of degradation during accelerated life testing.

  14. Ammonia Leaching Study on Lanping Carbonate Containing Silver Oxidised Copper Ores in Yunnan%兰坪燕子洞含银氧化铜矿常温常压氨浸试验研究

    Institute of Scientific and Technical Information of China (English)

    张铁民; 方建军; 蒋太国; 毛莹博

    2014-01-01

    The effects of oxidized copper ores which came from Lanping of Yunnan Province were studied using agitation leaching methods in laboratory in order to find out the optimum leaching conditions under normal temperature and pressure .Silver content of the ores was high .The ores belonged to typical carbonate minerals .The optimum conditions obtained were as follows:ammonia concentration 1.5 mol/L, granding fineness about 85% -0.074 mm, liquid -solid ratio 2.5∶1 and leching time 3 h.The leaching rate of this ore could reach 70%.%针对兰坪燕子洞碳酸盐型含银氧化铜矿石高碱性、高砷、高结合率的特点,进行了常温常压氨浸试验研究。研究表明:常温常压,在氨水浓度1.5 mol/L,碳酸氢铵浓度1.5 mol/L,磨矿细度-0.074 mm占85%,液固比2.5∶1,浸出时间3 h条件下,铜浸出率可达70%。氨浸液经萃取-电积可得到99.95%的电积铜,有效地实现了铜元素的回收利用。

  15. Comparative effects of dissolved copper and copper oxide nanoparticle exposure to the sea anemone, Exaiptasia pallida

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Samreen; Goddard, Russell H.; Bielmyer-Fraser, Gretchen K., E-mail: gkbielmyer@valdosta.edu

    2015-03-15

    Highlights: • Differences between CuO NP and CuCl{sub 2} exposure were characterized. • Copper accumulation in E. pallida was concentration-dependent. • E. pallida exposed to CuCl{sub 2} accumulated higher copper tissue burdens. • The oxidative stress response was greater in E. pallida exposed to CuO NP. • Both forms of copper inhibited CA activity in E. pallida. - Abstract: Increasing use of metal oxide nanoparticles (NP) by various industries has resulted in substantial output of these NP into aquatic systems. At elevated concentrations, NP may interact with and potentially affect aquatic organisms. Environmental implications of increased NP use are largely unknown, particularly in marine systems. This research investigated and compared the effects of copper oxide (CuO) NP and dissolved copper, as copper chloride (CuCl{sub 2}), on the sea anemone, Exaiptasia pallida. Sea anemones were collected over 21 days and tissue copper accumulation and activities of the enzymes: catalase, glutathione peroxidase, glutathione reductase, and carbonic anhydrase were quantified. The size and shape of CuO NP were observed using a ecanning electron microscope (SEM) and the presence of copper was confirmed by using Oxford energy dispersive spectroscopy systems (EDS/EDX). E. pallida accumulated copper in their tissues in a concentration- and time-dependent manner, with the animals exposed to CuCl{sub 2} accumulating higher tissue copper burdens than those exposed to CuO NP. As a consequence of increased copper exposure, as CuO NP or CuCl{sub 2}, anemones increased activities of all of the antioxidant enzymes measured to some degree, and decreased the activity of carbonic anhydrase. Anemones exposed to CuO NP generally had higher anti-oxidant enzyme activities than those exposed to the same concentrations of CuCl{sub 2}. This study is useful in discerning differences between CuO NP and dissolved copper exposure and the findings have implications for exposure of aquatic

  16. Handling of Copper and Copper Oxide Nanoparticles by Astrocytes.

    Science.gov (United States)

    Bulcke, Felix; Dringen, Ralf

    2016-02-01

    Copper is an essential trace element for many important cellular functions. However, excess of copper can impair cellular functions by copper-induced oxidative stress. In brain, astrocytes are considered to play a prominent role in the copper homeostasis. In this short review we summarise the current knowledge on the molecular mechanisms which are involved in the handling of copper by astrocytes. Cultured astrocytes efficiently take up copper ions predominantly by the copper transporter Ctr1 and the divalent metal transporter DMT1. In addition, copper oxide nanoparticles are rapidly accumulated by astrocytes via endocytosis. Cultured astrocytes tolerate moderate increases in intracellular copper contents very well. However, if a given threshold of cellular copper content is exceeded after exposure to copper, accelerated production of reactive oxygen species and compromised cell viability are observed. Upon exposure to sub-toxic concentrations of copper ions or copper oxide nanoparticles, astrocytes increase their copper storage capacity by upregulating the cellular contents of glutathione and metallothioneins. In addition, cultured astrocytes have the capacity to export copper ions which is likely to involve the copper ATPase 7A. The ability of astrocytes to efficiently accumulate, store and export copper ions suggests that astrocytes have a key role in the distribution of copper in brain. Impairment of this astrocytic function may be involved in diseases which are connected with disturbances in brain copper metabolism.

  17. Dry air effects on the copper oxides sensitive layers formation for ethanol vapor detection

    Energy Technology Data Exchange (ETDEWEB)

    Labidi, A., E-mail: Ahmed_laabidi@yahoo.fr [URPSC (UR 99/13-18) Unite de Recherche de Physique des Semiconducteurs et Capteurs, IPEST, Universite de Carthage, BP 51, La Marsa 2070, Tunis (Tunisia); Bejaoui, A.; Ouali, H. [URPSC (UR 99/13-18) Unite de Recherche de Physique des Semiconducteurs et Capteurs, IPEST, Universite de Carthage, BP 51, La Marsa 2070, Tunis (Tunisia); Akkari, F. Chaffar [Laboratoire de Photovoltaique et Materiaux Semi-conducteurs, ENIT, Universite de Tunis el Manar, BP 37, Le belvedere 1002, Tunis (Tunisia); Hajjaji, A.; Gaidi, M. [Laboratoire de Photovoltaique, Centre de Recherches et de technologies de l' energie, Technopole de Borj-Cedria, BP 95, 2050 Hammam-Lif (Tunisia); Kanzari, M. [Laboratoire de Photovoltaique et Materiaux Semi-conducteurs, ENIT, Universite de Tunis el Manar, BP 37, Le belvedere 1002, Tunis (Tunisia); Bessais, B. [Laboratoire de Photovoltaique, Centre de Recherches et de technologies de l' energie, Technopole de Borj-Cedria, BP 95, 2050 Hammam-Lif (Tunisia); Maaref, M. [URPSC (UR 99/13-18) Unite de Recherche de Physique des Semiconducteurs et Capteurs, IPEST, Universite de Carthage, BP 51, La Marsa 2070, Tunis (Tunisia)

    2011-09-15

    The copper oxide films have been deposited by thermal evaporation and annealed under ambient air and dry air respectively, at different temperatures. The structural characteristics of the films were investigated by X-ray diffraction. They showed the presences of two hydroxy-carbonate minerals of copper for annealing temperatures below 250 deg. C. Above this temperature the conductivity measurements during the annealing process, show a transition phase from metallic copper to copper oxides. The copper oxides sensitivity toward ethanol were performed using conductivity measurements at the working temperature of 200 deg. C. A decrease of conductivity was observed under ethanol vapor, showing the p-type semi-conducting characters of obtained copper oxide films. It was found that the sensing properties of copper oxide toward ethanol depend mainly on the annealing conditions. The best responses were obtained with copper layers annealed under dry air.

  18. Solubility of lead and copper in biochar-amended small arms range soils: influence of soil organic carbon and pH.

    Science.gov (United States)

    Uchimiya, Minori; Bannon, Desmond I

    2013-08-14

    Biochar is often considered a strong heavy metal stabilizing agent. However, biochar in some cases had no effects on, or increased the soluble concentrations of, heavy metals in soil. The objective of this study was to determine the factors causing some biochars to stabilize and others to dissolve heavy metals in soil. Seven small arms range soils with known total organic carbon (TOC), cation exchange capacity, pH, and total Pb and Cu contents were first screened for soluble Pb and Cu concentrations. Over 2 weeks successive equilibrations using weak acid (pH 4.5 sulfuric acid) and acetate buffer (0.1 M at pH 4.9), Alaska soil containing disproportionately high (31.6%) TOC had nearly 100% residual (insoluble) Pb and Cu. This soil was then compared with sandy soils from Maryland containing significantly lower (0.5-2.0%) TOC in the presence of 10 wt % (i) plant biochar activated to increase the surface-bound carboxyl and phosphate ligands (PS450A), (ii) manure biochar enriched with soluble P (BL700), and (iii) unactivated plant biochars produced at 350 °C (CH350) and 700 °C (CH500) and by flash carbonization (corn). In weak acid, the pH was set by soil and biochar, and the biochars increasingly stabilized Pb with repeated extractions. In pH 4.9 acetate buffer, PS450A and BL700 stabilized Pb, and only PS450A stabilized Cu. Surface ligands of PS450A likely complexed and stabilized Pb and Cu even under acidic pH in the presence of competing acetate ligand. Oppositely, unactivated plant biochars (CH350, CH500, and corn) mobilized Pb and Cu in sandy soils; the putative mechanism is the formation of soluble complexes with biochar-borne dissolved organic carbon. In summary, unactivated plant biochars can inadvertently increase dissolved Pb and Cu concentrations of sandy, low TOC soils when used to stabilize other contaminants.

  19. Direct production of carbon nanofibers decorated with Cu2O by thermal chemical vapor deposition on Ni catalyst electroplated on a copper substrate

    Directory of Open Access Journals (Sweden)

    MA Vesaghi

    2012-12-01

    Full Text Available  Carbon nanofibers (CNFs decorated with Cu2O particles were grown on a Ni catalyst layer deposited on a Cu substrate by thermal. chemical vapor deposition from liquid petroleum gas. Ni catalyst nanoparticles with different sizes were produced in an electroplating system at 35˚C. These nanoparticles provide the nucleation sites for CNF growth, removing the need for a buffer layer. High temperature surface segregation of the Cu substrate into the Ni catalyst layer and its exposition to O2 at atmospheric environment, during the CNFs growth, lead to the production of CNFs decorated with Cu2O particles. The surface morphology of the Ni catalyst films and grown CNFs over it was studied by scanning electron microscopy. Transmission electron microscopy and Raman spectroscopy revealed the formation of CNFs. The selected area electron diffraction pattern and electron diffraction studies show that these CNFs were decorated with Cu2O nanoparticles.

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

    OpenAIRE

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

    2011-01-01

    Hereditary forms of copper toxicosis exist in man and dogs. In man, Wilson’s disease is the best studied disorder of copper overload, resulting from mutations in the gene coding for the copper transporter ATP7B. Forms of copper toxicosis for which no causal gene is known yet are recognized as well, often in young children. Although advances have been made in unraveling the genetic background of disorders of copper metabolism in man, many questions regarding disease mechanisms and copper homeo...

  1. REMOVAL OF COPPER ELECTROLYTE CONTAMINANTS BY ADSORPTION

    Directory of Open Access Journals (Sweden)

    B Gabai

    1997-09-01

    Full Text Available Abstract - Selective adsorbents have become frequently used in industrial processes. Recent studies have shown the possibility of using adsorption to separate copper refinery electrolyte contaminants, with better results than those obtained with conventional techniques. During copper electrorefinning, many impurities may be found as dissolved metals present in the anode slime which forms on the electrode surface, accumulated in the electrolyte or incorporated into the refined copper on the cathode by deposition. In this study, synthetic zeolites, chelating resins and activated carbons were tested as adsorbents to select the best adsorbent performance, as well as the best operating temperature for the process. The experimental method applied was the finite bath, which consists in bringing the adsorbent into contact with a finite volume of electrolyte while controlling the temperature. The concentration of metals in the liquid phase was continuously monitored by atomic absorption spectrophotometry (AAS

  2. Hair copper in intrauterine copper device users.

    Science.gov (United States)

    Thiery, M; Heyndrickx, A; Uyttersprot, C

    1984-03-01

    The antifertility effect of copper-bearing IUDs is based on continuous release of copper, which is a result of the reaction between the metal and the uterine secretions. Released cupric ions collect in the endometrium and in the uterine fluid but significant accumulation has not been found in the bloodstream or elsewhere. Following Laker's suggestion that hair be used for monitoring essential trace elements, e.g., copper, we checked the copper content of the hair of women wearing copper-bearing IUDs. Samples of untreated pubic hair removed by clipping before diagnostic curettage were obtained from 10 young (24-34 years old), white caucasian females who until then had been wearing an MLCu250 IUD for more than 1 year. Pubes from 10 comparable (sex, age, race) subjects who had never used a Cu-containing device served as controls. The unwashed material was submitted to the toxicology laboratory, where the copper content was assessed by flameless atomic absorption, a technique whose lower limit of measurement lies at a concentration of 0.05 mcg Cu/ml fluid (50 ppb). Hair samples were washed to remove extraneous traces of metal according to the prescriptions of the International Atomic Energy Agency, weighed, and mineralized, after which a small volume (10 mcl) of the diluted fluid was fed into the graphite furnace. Each sample (75-150 mg) was analyzed 4 times, both before and after washing. Since the cleaning procedure reduces the weight of the sample (mainly by the removal of fat, dust, etc.) this explains why the percentage copper content of washed hair is higher than that of unwashed hair belonging to the same subject. The results indicate that there was no significant difference (Mann-Whitney U test) between the mean copper levels of both unwashed and washed pubes from women who were using or had never used an MLCu250 IUD. We therefore conclude that the use of this copper-containing device is not associated with significant accumulation of copper in (pubic) hair.

  3. China Copper Processing Industry Focus

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>1. Market Consumption The ’China Factor’ and Copper Price Fluctuation We all know China is an enormous consumer of copper,but the exact levels of consumption and where the copper has gone remains a mystery.

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

    Science.gov (United States)

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

    2013-09-01

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

  5. Development of highly faceted reduced graphene oxide-coated copper oxide and copper nanoparticles on a copper foil surface

    Directory of Open Access Journals (Sweden)

    Rebeca Ortega-Amaya

    2016-07-01

    Full Text Available This work describes the formation of reduced graphene oxide-coated copper oxide and copper nanoparticles (rGO-Cu2ONPs, rGO-CuNPs on the surface of a copper foil supporting graphene oxide (GO at annealing temperatures of 200–1000 °C, under an Ar atmosphere. These hybrid nanostructures were developed from bare copper oxide nanoparticles which grew at an annealing temperature of 80 °C under nitrogen flux. The predominant phase as well as the particle size and shape strongly depend on the process temperature. Characterization with transmission electron microscopy and scanning electron microscopy indicates that Cu or Cu2O nanoparticles take rGO sheets from the rGO network to form core–shell Cu–rGO or Cu2O–rGO nanostructures. It is noted that such ones increase in size from 5 to 800 nm as the annealing temperature increases in the 200–1000 °C range. At 1000 °C, Cu nanoparticles develop a highly faceted morphology, displaying arm-like carbon nanorods that originate from different facets of the copper crystal structure.

  6. Development of highly faceted reduced graphene oxide-coated copper oxide and copper nanoparticles on a copper foil surface

    Science.gov (United States)

    Matsumoto, Yasuhiro; Espinoza-Rivas, Andrés M; Pérez-Guzmán, Manuel A; Ortega-López, Mauricio

    2016-01-01

    Summary This work describes the formation of reduced graphene oxide-coated copper oxide and copper nanoparticles (rGO-Cu2ONPs, rGO-CuNPs) on the surface of a copper foil supporting graphene oxide (GO) at annealing temperatures of 200–1000 °C, under an Ar atmosphere. These hybrid nanostructures were developed from bare copper oxide nanoparticles which grew at an annealing temperature of 80 °C under nitrogen flux. The predominant phase as well as the particle size and shape strongly depend on the process temperature. Characterization with transmission electron microscopy and scanning electron microscopy indicates that Cu or Cu2O nanoparticles take rGO sheets from the rGO network to form core–shell Cu–rGO or Cu2O–rGO nanostructures. It is noted that such ones increase in size from 5 to 800 nm as the annealing temperature increases in the 200–1000 °C range. At 1000 °C, Cu nanoparticles develop a highly faceted morphology, displaying arm-like carbon nanorods that originate from different facets of the copper crystal structure. PMID:27547618

  7. Effect of Copper and Bronze Addition on Corrosion Resistance of Alloyed 316L Stainless Steel Cladded on Plain Carbon Steel by Powder Metallurgy

    Institute of Scientific and Technical Information of China (English)

    Wenjue CHEN; Yueying WU; Jianian SHEN

    2004-01-01

    A sandwich structure with cladding alloyed 316L stainless steel on plain carbon steel was prepared by means of powder metallurgy (PM) processing. Electrolytic Cu and prealloyed bronze (95Cu wt pct, 5Sn wt pct) were added in different contents up to 15% into the surface cladded 316L layers and the effect of alloying concentrations on the corrosion resistance of the 316L cladding layers was studied. The corrosion performances of the cladding samples were studied by immersion tests and potentio-dynamic anodic polarization tests in H2SO4 and FeCl3 solutions. Both 316L and alloyed 316L surface layers with 1.0 mm depth produced by PM cladding had an effect to improve corrosion resistance in H2SO4 and FeCl3 solutions. Small Cu and bronze addition (4%) had a positive effect in H2SO4 and FeCl3 solutions. 4% Cu alloyed 316L surface layer produced by PM cladding showed similar anodic polarization behaviour to the 316L cladding layer in H2SO4 and FeCl3 solutions.

  8. Copper recovery and cyanide oxidation by electrowinning from a spent copper-cyanide electroplating electrolyte.

    Science.gov (United States)

    Dutra, A J B; Rocha, G P; Pombo, F R

    2008-04-01

    Copper-cyanide bleed streams arise from contaminated baths from industrial electroplating processes due to the buildup of impurities during continuous operation. These streams present an elevated concentration of carbonate, cyanide and copper, constituting a heavy hazard, which has to be treated for cyanide destruction and heavy metals removal, according to the local environmental laws. In the Brazilian Mint, bleed streams are treated with sodium hypochlorite, to destroy cyanide and precipitate copper hydroxide, a solid hazardous waste that has to be disposed properly in a landfill or treated for metal recovery. In this paper, a laboratory-scale electrolytic cell was developed to remove the copper from the bleed stream of the electroplating unit of the Brazilian Mint, permitting its reutilization in the plant and decreasing the amount of sludge to waste. Under favorable conditions copper recoveries around 99.9% were achieved, with an energy consumption of about 11 kWh/kg, after a 5-h electrolysis of a bath containing copper and total cyanide concentrations of 26 and 27 g/L, respectively. Additionally, a substantial reduction of the cyanide concentration was also achieved, decreasing the pollution load and final treatment costs.

  9. Electrochemical and morphological characterisation of polyphenazine films on copper

    Energy Technology Data Exchange (ETDEWEB)

    Gouveia-Caridade, Carla; Romeiro, Andreia; Brett, Christopher M.A., E-mail: cbrett@ci.uc.pt

    2013-11-15

    The morphology of films of the phenazine polymers poly(neutral red) (PNR), poly(brilliant cresyl blue) (PBCB), poly(Nile blue A) (PNB) and poly(safranine T) (PST), formed by potential cycling electropolymerisation on copper electrodes, in order to reduce the corrosion rate of copper, has been examined by scanning electron microscopy (SEM). The copper surface was initially partially passivated in sodium oxalate, hydrogen carbonate or salicylate solution, in order to inhibit copper dissolution at potentials where phenazine monomer oxidation occurs, and to induce better polymer film adhesion. SEM images were also taken of partially passivated copper in order to throw light on the different morphology and anti-corrosive behaviour of the polyphenazine films. Analysis of the morphology of the polymer-coated copper with best anti-corrosive behaviour after 72 h immersion in 0.1 M KCl, Cu/hydrogen carbonate/PNB, showed that the surface is completely covered by closely packed crystals. By contrast, images of PST films on copper partially passivated in oxalate solution, that had the least protective behaviour, showed large amounts of insoluble corrosion products after only 4 h immersion in 0.1 M KCl.

  10. Copper and silver halates

    CERN Document Server

    Woolley, EM; Salomon, M

    2013-01-01

    Copper and Silver Halates is the third in a series of four volumes on inorganic metal halates. This volume presents critical evaluations and compilations for halate solubilities of the Group II metals. The solubility data included in this volume are those for the five compounds, copper chlorate and iodate, and silver chlorate, bromate and iodate.

  11. Coping with copper

    DEFF Research Database (Denmark)

    Nunes, Ines; Jacquiod, Samuel; Brejnrod, Asker

    2016-01-01

    Copper has been intensively used in industry and agriculture since mid-18(th) century and is currently accumulating in soils. We investigated the diversity of potential active bacteria by 16S rRNA gene transcript amplicon sequencing in a temperate grassland soil subjected to century-long exposure......, suggesting a potential promising role as bioindicators of copper contamination in soils....

  12. 铝炭微电解对含铜、镍电镀废水的处理实验研究%Experimental study on the treatment of electroplating wastewater containing copper and nickel by aluminum-carbon micro-electrolysis method

    Institute of Scientific and Technical Information of China (English)

    张志军; 陈整生; 胡娟; 刘东飞

    2012-01-01

    在铁炭微电解的基础上,研究了铝炭微电解对含铜、镍电镀废水的处理效果,考察了铝炭比、反应时间、进水pH对处理效果的影响.结果表明,铝炭微电解最佳反应时间由铁炭微电解的30 min减少到15 min;Cu2+去除率由铁炭微电解的95%提高到98%,Ni2+去除率由铁炭微电解的94%提高到97%.此项研究为铝炭微电解处理电镀废水的实际应用奠定了基础.%Based on iron-carbon micro-electrolysis process,the effectiveness of the treatment of electroplating wastewater containing copper and nickel by aluminum-carbon process has been studied. The effects of aluminum carbon ratio,reaction time,and influent water pH on the treatment effectiveness are investigated. The results show that the best reaction time of aluminum-carbon micro-electrolysis is reduced to 15 min, while that of iron-carbon micro-electrolysis is 30 min. The Cu2+ removing rate of aluminum-carbon micro-electrolysis has been increased to 98%, while that of iron-carbon micro-electrolysis is 95%. The Ni2+ removing rate of aluminium-carbon micro-electrolysis has been increased to 97% , while that of iron-carbon micro-electrolysis is 94% . This research has thus laid foundations for the actual application of aluminum-carbon micro-electrolysis to the treatment of electroplating wastewater.

  13. Kunpeng Copper:The largest Copper Smelting Company of Sichuan

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>On September 9,Liangshan Mining Company’s 100,000 tons/year cathode copper project kicked off.It is another key project of the company following the successful launch of the 100,000 tons/year anode copper project.Based on ISA copper smelting technology of the largest open-cast copper mine in southwest China,

  14. Trace element determination-I Use of 2,9-dimethyl-1,10-phenanthroline in determination of copper in heavy matrices by carbon furnace atomic-absorption spectrometry.

    Science.gov (United States)

    Battistoni, P; Bruni, P; Cardellini, L; Fava, G; Gobbi, G

    1980-08-01

    A method for the determination of copper in complex matrices by electrothermal atomic-absorption spectrometry has been developed. It uses neocuproine as complexing agent. The detection limit is 0.2 ng/ml, and interferences are minimized.

  15. Determination of factors responsible for the bioweathering of copper minerals from organic-rich copper-bearing Kupferschiefer black shale.

    Science.gov (United States)

    Włodarczyk, Agnieszka; Szymańska, Agata; Skłodowska, Aleksandra; Matlakowska, Renata

    2016-04-01

    The aim of this study was to investigate the bioweathering of copper minerals present in the alkaline, copper-bearing and organic-rich Kupferschiefer black shale through the action of a consortium of indigenous lithobiontic, heterotrophic, neutrophilic bacteria isolated from this sedimentary rock. The involvement of microorganisms in the direct/enzymatic bioweathering of fossil organic matter of the rock was confirmed. As a result of bacterial activity, a spectrum of various organic compounds such as urea and phosphoric acid tributyl ester were released from the rock. These compounds indirectly act on the copper minerals occurring in the rock and cause them to weather. This process was reflected in the mobilization of copper, iron and sulfur and in changes in the appearance of copper minerals observed under reflected light. The potential role of identified enzymes in biodegradation of fossil organic matter and role of organic compounds released from black shale as a result of this process in copper minerals weathering was discussed. The presented results provide a new insight into the role of chemical compounds released by bacteria during fossil organic matter bioweathering potentially important in the cycling of copper and iron deposited in the sedimentary rock. The originality of the described phenomenon lies in the fact that the bioweathering of fossil organic matter and, consequently, of copper minerals occur simultaneously in the same environment, without any additional sources of energy, electrons and carbon.

  16. Posttranslational regulation of copper transporters

    NARCIS (Netherlands)

    van den Berghe, P.V.E.

    2009-01-01

    The transition metal copper is an essential cofactor for many redox-active enzymes, but excessive copper can generate toxic reactive oxygen species. Copper homeostasis is maintained by highly conserved proteins, to balance copper uptake, distribution and export on the systemic and cellular level. Th

  17. Estimation of CO2-Equivalent Emission under the Copper Fire Refining Process

    Science.gov (United States)

    Chesnokov, Yu N.; Lisienko, V. G.; Holod, S. I.; Anufriev, V. P.; Lapteva, A. V.

    2017-06-01

    Non-ferrous metallurgy is one of the most energy-consuming and carbon-emissive sectors of industry. This is due to the fact that the volume of greenhouse gas (GHG) emissions is stipulated by energy consumption. Uralelectromed is a city-forming enterprise of the Verkhnyaya Pyshma. The situation is similar other cities of the old industrial regions of the Russian Federation (Krasnouralsk, Verkhnaya Salda, Karabash, etc.) Verkhnyaya Pyshma has many characteristics of “a clever city”. It can be compared to Hamburg where blister copper is being produced at the center of the city at a copper smelting plant Aurubis. Following the example of such ecologically clean country as Germany and in order to assess how modern energy-efficient low-carbon technologies can provide a favorable habitat, and an acceptable level of carbon footprint, the authors estimated the level of greenhouse gas, i.e., carbon dioxide emission produced by the Uralelectromed. The emission of greenhouse gas -carbon dioxide in the process of fire refining of blister copper has been calculated. The anode melting process consists of several stages where the most important ones are melting of charge, oxidation, and copper melt reduction. Calculations are based on taking into account the mass of burnt carbon of natural gas and the thermal dissociation of fuel oil. It implies that a complete combustion of carbon takes place. The specific value of carbon dioxide emission of the copper refining process is averaged 181 kg CO2 per 1 ton of anode copper.

  18. Copper Nanoparticles in Click Chemistry.

    Science.gov (United States)

    Alonso, Francisco; Moglie, Yanina; Radivoy, Gabriel

    2015-09-15

    The challenges of the 21st century demand scientific and technological achievements that must be developed under sustainable and environmentally benign practices. In this vein, click chemistry and green chemistry walk hand in hand on a pathway of rigorous principles that help to safeguard the health of our planet against negligent and uncontrolled production. Copper-catalyzed azide-alkyne cycloaddition (CuAAC), the paradigm of a click reaction, is one of the most reliable and widespread synthetic transformations in organic chemistry, with multidisciplinary applications. Nanocatalysis is a green chemistry tool that can increase the inherent effectiveness of CuAAC because of the enhanced catalytic activity of nanostructured metals and their plausible reutilization capability as heterogeneous catalysts. This Account describes our contribution to click chemistry using unsupported and supported copper nanoparticles (CuNPs) as catalysts prepared by chemical reduction. Cu(0)NPs (3.0 ± 1.5 nm) in tetrahydrofuran were found to catalyze the reaction of terminal alkynes and organic azides in the presence of triethylamine at rates comparable to those achieved under microwave heating (10-30 min in most cases). Unfortunately, the CuNPs underwent dissolution under the reaction conditions and consequently could not be recovered. Compelling experimental evidence on the in situ generation of highly reactive copper(I) chloride and the participation of copper(I) acetylides was provided. The supported CuNPs were found to be more robust and efficient catalyst than the unsupported counterpart in the following terms: (a) the multicomponent variant of CuAAC could be applied; (b) the metal loading could be substantially decreased; (c) reactions could be conducted in neat water; and (d) the catalyst could be recovered easily and reutilized. In particular, the catalyst composed of oxidized CuNPs (Cu2O/CuO, 6.0 ± 2.0 nm) supported on carbon (CuNPs/C) was shown to be highly versatile and very

  19. Fabricating Copper Nanotubes by Electrodeposition

    Science.gov (United States)

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

    2009-01-01

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

  20. [Copper and the human body].

    Science.gov (United States)

    Krízek, M; Senft, V; Motán, J

    1997-11-19

    Copper is one of the essential trace elements. It is part of a number of enzymes. Deficiency of the element is manifested by impaired haematopoesis, bone metabolism, disorders of the digestive, cardiovascular and nervous system. Deficiency occurs in particular in patients suffering from malnutrition, malabsorption, great copper losses during administration of penicillamine. Sporadically copper intoxications are described (suicidal intentions or accidental ingestion of beverages with a high copper content). Acute exposure to copper containing dust is manifested by metal fume fever. Copper salts can produce local inflammations. Wilson's disease is associated with inborn impaired copper metabolism. In dialyzed patients possible contaminations of the dialyzate with copper must be foreseen as well as the possible release of copper from some dialyzation membranes. With the increasing amount of copper in the environment it is essential to monitor the contamination of the environment.

  1. Effect of chromium and carbon contents in cast iron on bonded microstructure of copper brazed high chromium cast iron and mild steel. Braze ho ni yoru kokuromu chutetsu to ko hagane no setsugo soshiki ni oyobosu chutetsuchu kuromu oyobi tansoryo no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Sasaguri, N.; Matsubara, Y. (Kurume College of Technology, Fukuoka (Japan)); Ogi, K. (Kyushu University, Fukuoka (Japan))

    1993-08-25

    For the purpose of enhancing toughness, workability and weldability of high chromium castiron, hypoeutectic, eutectic and hypereutectic high chromium cast irons containing 10 to 30mass% Cr and mild steel were bonded by the brazing method using pure copper filler. This paper describes the effect of chromium and carbon contents in cast iron on the microstructural variations and behaviors of alloying elements in the bonded zone. The length of rod-like crystal precipitated at the cast iron-copper interface and the width of bonded zone decreased with an increase in Cr/C value of cast iron. It was considered that this is because diffusion of iron from steel to cast iron becomes less due to the decrease of difference in chemical potential of iron between the cast iron and the steel sides. Furthermore, alloy phase was composed of Fe, Cr, Cu and C, and the iron concentration in the alloy phase decreased and the chromium concentration increased with increasing the Cr/C value. The copper concentration was almost constant independent of the Cr/C value. It was suggested that the growth of alloy phase occurs under the diffusion control. 9 refs., 10 figs., 1 tab.

  2. Targeting copper in cancer therapy: 'Copper That Cancer'.

    Science.gov (United States)

    Denoyer, Delphine; Masaldan, Shashank; La Fontaine, Sharon; Cater, Michael A

    2015-11-01

    Copper is an essential micronutrient involved in fundamental life processes that are conserved throughout all forms of life. The ability of copper to catalyze oxidation-reduction (redox) reactions, which can inadvertently lead to the production of reactive oxygen species (ROS), necessitates the tight homeostatic regulation of copper within the body. Many cancer types exhibit increased intratumoral copper and/or altered systemic copper distribution. The realization that copper serves as a limiting factor for multiple aspects of tumor progression, including growth, angiogenesis and metastasis, has prompted the development of copper-specific chelators as therapies to inhibit these processes. Another therapeutic approach utilizes specific ionophores that deliver copper to cells to increase intracellular copper levels. The therapeutic window between normal and cancerous cells when intracellular copper is forcibly increased, is the premise for the development of copper-ionophores endowed with anticancer properties. Also under investigation is the use of copper to replace platinum in coordination complexes currently used as mainstream chemotherapies. In comparison to platinum-based drugs, these promising copper coordination complexes may be more potent anticancer agents, with reduced toxicity toward normal cells and they may potentially circumvent the chemoresistance associated with recurrent platinum treatment. In addition, cancerous cells can adapt their copper homeostatic mechanisms to acquire resistance to conventional platinum-based drugs and certain copper coordination complexes can re-sensitize cancer cells to these drugs. This review will outline the biological importance of copper and copper homeostasis in mammalian cells, followed by a discussion of our current understanding of copper dysregulation in cancer, and the recent therapeutic advances using copper coordination complexes as anticancer agents.

  3. Study on the thermal conductivity of diamond-like carbon functionally graded material on copper substrate%铜基类金刚石膜功能梯度材料作为散热材料的研究

    Institute of Scientific and Technical Information of China (English)

    王静; 刘贵昌; 李红玲; 侯保荣

    2012-01-01

    随着电子技术、信息产业的发展,Cu在微型散热材料、电子封装材料上应用日益广泛.Cu在应用过程中存在强度低、易氧化、易磨损等缺点.采用等离子体复合沉积技术,在铜基体上制备了Ti/TiC/DLC功能梯度材料,改善铜基体与美金刚石(DLC)膜的结合力,强化了铜的机械性能.瞬态热反射法检测结果表明,DLC功能梯度材料不会影响铜基体的散热效果.%In recent years, with the rapid development of electronic technology and digital network information, copper has increasing applications in micro-electronics, micro-electro-mechanical systems and Hi-tech materials. However copper has its material limitations. In particular, it has relatively low hardness, high oxidation and wear rate, which have severely restricted its widespread applications. In this paper, aiming at difficulties of copper applications, Ti/TiC/DLC has been proposed as functionally graded material to deposit on the copper substrate with plasma depositing method, which intensifies the adhesion between DLC film and copper substrate and improves the properties of copper. The maximal value of thermal conductivity of DLC film with optimized parameter of graded intermediate layer is 3.63 Wm-1.K-1, which enhances the heat transfer effect of copper substrate.

  4. Contribution of natural organic matter to copper leaching from municipal solid waste incinerator bottom ash

    NARCIS (Netherlands)

    Zomeren, van A.; Comans, R.N.J.

    2004-01-01

    The leaching of heavy metals, such as copper, from municipal solid waste incinerator (MSWI) bottom ash is a concern in many countries and may inhibit the beneficial reuse of this secondary material. The enhanced leaching of copper from three MSWI bottom ash samples by dissolved organic carbon (DOC)

  5. LEP copper accelerating cavities

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    These copper cavities were used to generate the radio frequency electric field that was used to accelerate electrons and positrons around the 27-km Large Electron-Positron (LEP) collider at CERN, which ran from 1989 to 2000. The copper cavities were gradually replaced from 1996 with new superconducting cavities allowing the collision energy to rise from 90 GeV to 200 GeV by mid-1999.

  6. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  7. Alternative Anode Reaction for Copper Electrowinning

    Energy Technology Data Exchange (ETDEWEB)

    2005-07-01

    This report describes a project funded by the Department of Energy, with additional funding from Bechtel National, to develop a copper electrowinning process with lower costs and lower emissions than the current process. This new process also includes more energy efficient production by using catalytic-surfaced anodes and a different electrochemical couple in the electrolyte, providing an alternative oxidation reaction that requires up to 50% less energy than is currently required to electrowin the same quantity of copper. This alternative anode reaction, which oxidizes ferric ions to ferrous, with subsequent reduction back to ferric using sulfur dioxide, was demonstrated to be technically and operationally feasible. However, pure sulfur dioxide was determined to be prohibitively expensive and use of a sulfur burner, producing 12% SO{sub 2}, was deemed a viable alternative. This alternate, sulfur-burning process requires a sulfur burner, waste heat boiler, quench tower, and reaction towers. The electrolyte containing absorbed SO{sub 2} passes through activated carbon to regenerate the ferrous ion. Because this reaction produces sulfuric acid, excess acid removal by ion exchange is necessary and produces a low concentration acid suitable for leaching oxide copper minerals. If sulfide minerals are to be leached or the acid unneeded on site, hydrogen was demonstrated to be a potential reductant. Preliminary economics indicate that the process would only be viable if significant credits could be realized for electrical power produced by the sulfur burner and for acid if used for leaching of oxidized copper minerals on site.

  8. Decomposition Studies of Triphenylboron, Diphenylborinic Acid and Phenylboric Acid in Aqueous Alkaline Solutions Containing Copper

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, C.L. [Westinghouse Savannah River Company, AIKEN, SC (United States); Peterson, R. A.

    1997-02-11

    This report documents the copper-catalyzed chemical kinetics of triphenylboron, diphenylborinic acid and phenylboric acid (3PB, 2PB and PBA) in aqueous alkaline solution contained in carbon-steel vessels between 40 and 70 degrees C.

  9. Smelting reduction and kinetics analysis of magnetic iron in copper slag using waste cooking oil.

    Science.gov (United States)

    Li, Bo; Wang, Xubin; Wang, Hua; Wei, Yonggang; Hu, Jianhang

    2017-05-25

    To improve the recovery of copper, the viscosity of copper molten slag is decreased by the reduction of magnetic iron, which, in turn, accelerates the settling and separation of copper droplets from the slag. A new technology is proposed in which waste cooking oil is used as a reductant to reduce magnetic iron in the copper smelting slag and consequently reduce carbon emissions in the copper smelting process. A kinetic model of the reduction of magnetic iron in copper slag by waste cooking oil was built using experimental data, and the accuracy of the model was verified. The results indicated that the magnetic iron content in the copper slag decreased with increasing reduction time and an increase in temperature more efficiently reduced magnetic iron in the copper slag. The magnetic iron in the copper slag gradually transformed to fayalite, and the viscosity of the copper molten slag decreased as the magnetic iron content decreased during the reduction process. The reduction of magnetic iron in the copper molten slag using waste cooking oil was a first-order reaction, and the rate-limiting step was the mass transfer of Fe3O4 through the liquid boundary layer.

  10. Diffuse emission and control of copper in urban surface runoff.

    Science.gov (United States)

    Boller, M A; Steiner, M

    2002-01-01

    Copper washed off from roofs and roads is considered to be a major contribution to diffuse copper pollution of urban environments. In order to guarantee sustainable protection of soils and water, the long-term strategy is to avoid or replace copper containing materials on roofs and fagades. Until achievement of this goal, a special adsorber system is suggested to control the diffuse copper fluxes by retention of copper by a mixture of granulated iron-hydroxide (GEH) and calcium carbonate. Since future stormwater runoff concepts are based on decentralised runoff infiltration into the underground, solutions are proposed which provide for copper retention in infiltration sites using GEH adsorption layers. The example of a large copper façade of which the runoff is treated in an adsorption trench reveals the first full-scale data on façade runoff and adsorber performance. During the first year of investigation average façade runoff concentrations in the range of 1-10 mg Cu/l are reduced by 96-99% in the adsorption ditch.

  11. Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2015-01-01

    Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

  12. Pitting corrosion of copper. An equilibrium - mass transport study

    Energy Technology Data Exchange (ETDEWEB)

    Taxen, C. [Swedish Corrosion Inst., Stockholm (Sweden)

    2002-08-01

    A mathematical model for the propagation of corrosion pits is described and used to calculate the potentials below which copper is immune to pitting. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles of 26 aqueous species from the bulk water outside a corrosion pit to the site of the metal dissolution. Precipitation of oxides and salts of copper is considered. Studied conditions include water compositions from tap waters to seawater at the temperatures 25 deg C and 75 deg C. Carbonate and sulphate are aggressive towards copper because of complex formation with divalent copper. Carbonate is less aggressive in a corrosion pit than outside at the pH of the bulk. Carbonate carries acidity out from the pit, favours oxide formation and may prevent the initiation of acidic corrosion pits. The concentration profiles are used to estimate the maximum propagation rates for a corrosion pit. A high potential is found to be the most important factor for the rate of propagation. The levels of potential copper can sustain, as corrosion potentials are discussed in terms of the stability of cuprous oxide as a cathode material for oxygen reduction relative to non-conducting cupric phases.

  13. Dielectric Properties of Reduced Graphene Oxide/Copper Phthalocyanine Nanocomposites Fabricated Through π- π Interaction

    Science.gov (United States)

    Wang, Zicheng; Wei, Renbo; Liu, Xiaobo

    2017-01-01

    Reduced graphene oxide/copper phthalocyanine nanocomposites are successfully prepared through a simple and effective two-step method, involving preferential reduction of graphene oxide and followed by self-assembly with copper phthalocyanine. The results of photographs, ultraviolet visible, x-ray diffraction, x-ray photoelectron spectroscopy, and scanning electron microscopy show that the in situ blending method can effectively facilitate graphene sheets to disperse homogenously in the copper phthalocyanine matrix through π- π interactions. As a result, the reduction of graphene oxide and restoration of the sp 2 carbon sites in graphene can enhance the dielectric properties and alternating current conductivity of copper phthalocyanine effectively.

  14. Copper and Copper Proteins in Parkinson’s Disease

    OpenAIRE

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

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased pr...

  15. Jiangxi Copper Plans to Increase its Refined Copper Output

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>According to news published on March 30th, China’s largest copper producer--Jiangxi Copper alleged in its 2010 Financial Report Statement that it plans to improve its output of refined copper by 4.4% in 2011, to increase from 900,000 tonnes last year to 940,000 tons.

  16. [Copper metabolism and genetic disorders].

    Science.gov (United States)

    Shimizu, Norikazu

    2016-07-01

    Copper is one of essential trace elements. Copper deficiency lead to growth and developmental failure and/or neurological dysfunction. However, excess copper is also problems for human life. There are two disorders of inborn error of copper metabolism, Menkes disease and Wilson disease. Menkes disease is an X linked recessive disorder with copper deficiency and Wilson disease is an autosomal recessive disorder with copper accumulation. These both disorders result from the defective functioning of copper transport P-type ATPase, ATP7A of Menkes disease and ATP7B of Wilson disease. In this paper, the author describes about copper metabolism of human, and clinical feature, diagnosis and treatment of Menkes disease and Wilson disease.

  17. Chinese Copper Manufacturers Expand Overseas

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>In 2012,China’s apparent copper consumption reached 8.84 million tons,accounting for 43%of the global total demand.Spurred by strong demand,China’s copper smelting capacity roars with annual average growth in domestic copper smelting capacity reaching approx-

  18. CARBON DIOXIDE SEQUESTRATION BY ULTRAMAFIC-HOSTED MINE TAILINGS: EXAMPLE FROM JINCHUAN COPPER-NICKEL MINE TAILING%应用超基性岩尾矿封存CO2——以金川铜镍矿尾矿为例

    Institute of Scientific and Technical Information of China (English)

    李子波; 刘连文; 赵良; 季峻峰; 陈骏

    2011-01-01

    通过CO2矿物封存可以降低人类活动产生的温室气体的排放,富镁硅酸盐矿物经碳酸盐化作用转化为镁碳酸盐矿物可以实现CO2的封存,而超基性岩尾矿是CO2矿物封存的理想原料.我国可用于封存CO2的超基性岩尾矿包括铜镍矿尾矿、石棉尾矿、蛇纹石尾矿以及钒钛磁铁矿尾矿等.本文重点介绍金川铜镍矿尾矿的粒度、矿物组成、常量和微量元素,以及其自然风化固碳能力和CO2封存潜力.该研究通过对金川铜镍矿1号尾矿坝和2号尾矿坝样品的粒度、元素、红外光谱、扫描电镜、X-射线衍射以及选择性淋溶结果分析,发现1号尾矿坝和2号尾矿坝中五水菱镁矿(lansfordite)的平均含量分别为4.19wt%和1.95wt%,初步估算出金川铜镍矿尾矿自然风化固定大气中CO2的量高达70.68×10t.对尾矿中所含有价金属进行综合利用可以极大的降低CO2矿物封存成本.%Anthropogenic greenhouse gas emissions may be offset by carbon dioxide mineral sequestration, through carbonation of magnesium silicate minerals to form magnesium carbonate minerals. Ultramafic-hosted mine tailings are ideal raw material for carbon dioxide mineral sequestration. Tailings that can be used to sequestrate carbon dioxide include copper-nickel mine tailings, chrysotile mine tailings, serpentine mine tailings, and V-Ti-magnetite mine tailings in China. We analyzed the particle size, mineral composition, major elements and trace elements, and the potential and capability of natural weathering for carbon dioxide sequestration in Jinchuan copper-nickel mine tailing. Jinchuan is located in the middle of Gansu, China(38° 29'N, 102° 10'E) at an elevation of 1563m. To examine the capability of carbon dioxide fixed in Jinchuan copper-nickel mine tailing, a profile was dug in tailing Dam No. 1 and 9 samples were collected at 10cm intervals,and 5 other samples were collected from Dam No. 2.Particle size ,XRF, FT-IR, XRD, and

  19. Fabrication and Characterization of Metallic Copper and Copper Oxide Nanoflowers

    Directory of Open Access Journals (Sweden)

    *H. S. Virk

    2011-12-01

    Full Text Available Copper nanoflowers have been fabricated using two different techniques; electro-deposition of copper in polymer and anodic alumina templates, and cytyltrimethal ammonium bromide (CTAB-assisted hydrothermal method. Scanning Electron Microscope (SEM images record some interesting morphologies of metallic copper nanoflowers. Field Emission Scanning Electron Microscope (FESEM has been used to determine morphology and composition of copper oxide nanoflowers. X-ray diffraction (XRD pattern reveals the monoclinic phase of CuO in the crystallographic structure of copper oxide nanoflowers. There is an element of random artistic design of nature, rather than science, in exotic patterns of nanoflowers fabricated in our laboratory.

  20. From carbon nanotubes to carbon atomic chains

    Science.gov (United States)

    Casillas García, Gilberto; Zhang, Weijia; José-Yacamán, Miguel

    2010-10-01

    Carbyne is a linear allotrope of carbon. It is formed by a linear arrangement of carbon atoms with sp-hybridization. We present a reliable and reproducible experiment to obtain these carbon atomic chains using few-layer-graphene (FLG) sheets and a HRTEM. First the FLG sheets were synthesized from worm-like exfoliated graphite and then drop-casted on a lacey-carbon copper grid. Once in the TEM, two holes are opened near each other in a FLG sheet by focusing the electron beam into a small spot. Due to the radiation, the carbon atoms rearrange themselves between the two holes and form carbon fibers. The beam is concentrated on the carbon fibers in order excite the atoms and induce a tension until multi wall carbon nanotube (MWCNT) is formed. As the radiation continues the MWCNT breaks down until there is only a single wall carbon nanotube (SWCNT). Then, when the SWCNT breaks, an atomic carbon chain is formed, lasts for several seconds under the radiation and finally breaks. This demonstrates the stability of this carbon structure.

  1. Recovery of copper through decontamination of synthetic solutions using modified barks

    Science.gov (United States)

    Gaballah, I.; Goy, D.; Allain, E.; Kilbertus, G.; Thauront, J.

    1997-02-01

    Decontamination of synthetic acetate, chloride, nitrate, and sulfate solutions containing 10, 100, 1,000, 10,000, and 50,000 ppm of copper using chemically treated barks has been studied. Metal percentage removal from solutions depends on the pH, the initial concentration, and, to some extent, the anion. It varies from 40 through 99 pct of the initial metallic ion’s content in the solution. The average retention capacity of the treated bark is about 43 mg of Cu/g of dry modified bark (0.68 mmole/g of dry bark). Extraction of copper cations from the saturated modified bark was made possible with dilute acid. Regeneration of bark for reuse as an ion exchanger was possible. Bark loaded with copper was analyzed by scanning electron microscopy (SEM) and infrared (IR) spectroscopy. Copper was uniformly distributed in the bulk of the bark. No copper segregation was observed. It seems that copper was bound to the acidic (phenolic) sites of the bark. Anions were not detected on the copper-loaded bark with either SEM electron probe microanalysis or IR spectroscopy. Incineration of the bark loaded with copper resulted in ashes containing about 77 pct of copper oxides, while pyrolysis of the same sample led to ashes containing 10 pct of metallic copper and about 85 pct carbon.

  2. Selective LPCVD growth of graphene on patterned copper and its growth mechanism

    Science.gov (United States)

    Zhang, M.; Huang, B.-C.; Wang, Y.; Woo, J. C. S.

    2016-12-01

    Copper-catalyzed graphene low-pressure chemical-vapor deposition (LPCVD) growth has been regarded as a viable solution towards its integration to CMOS technology, and the wafer-bonding method provides a reliable alternative for transferring the selective graphene grown on a patterned metal film for IC manufacturing. In this paper, selective LPCVD graphene growth using patterned copper dots has been studied. The Raman spectra of grown films have demonstrated large dependence on the growth conditions. To explain the results, the growth mechanisms based on surface adsorption and copper-vapor-assisted growth are investigated by the comparison between the blanket copper films with/without the additional copper source. The copper vapor density is found to be critical for high-quality graphene growth. In addition, the copper-vapor-assisted growth is also evidenced by the carbon deposition on the SiO2 substrate of the patterned-copper-dot sample and chamber wall during graphene growth. This growth mechanism explains the correlation between the growth condition and Raman spectrum for films on copper dots. The study on the copper-catalyzed selective graphene growth on the hard substrate paves the way for the synthesis and integration of the 2D material in VLSI.

  3. Copper removal using a heavy-metal resistant microbial consortium in a fixed-bed reactor.

    Science.gov (United States)

    Carpio, Isis E Mejias; Machado-Santelli, Glaucia; Sakata, Solange Kazumi; Ferreira Filho, Sidney Seckler; Rodrigues, Debora Frigi

    2014-10-01

    A heavy-metal resistant bacterial consortium was obtained from a contaminated river in São Paulo, Brazil and utilized for the design of a fixed-bed column for the removal of copper. Prior to the design of the fixed-bed bioreactor, the copper removal capacity by the live consortium and the effects of copper in the consortium biofilm formation were investigated. The Langmuir model indicated that the sorption capacity of the consortium for copper was 450.0 mg/g dry cells. The biosorption of copper into the microbial biomass was attributed to carboxyl and hydroxyl groups present in the microbial biomass. The effect of copper in planktonic cells to form biofilm under copper rich conditions was investigated with confocal microscopy. The results revealed that biofilm formed after 72 h exposure to copper presented a reduced thickness by 57% when compared to the control; however 84% of the total cells were still alive. The fixed-bed bioreactor was set up by growing the consortium biofilm on granular activated carbon (GAC) and analyzed for copper removal. The biofilm-GAC (BGAC) column retained 45% of the copper mass present in the influent, as opposed to 17% in the control column that contained GAC only. These findings suggest that native microbial communities in sites contaminated with heavy metals can be immobilized in fixed-bed bioreactors and used to treat metal contaminated water.

  4. Copper and Copper Proteins in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Sergio Montes

    2014-01-01

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

  5. Industrial experiment of copper electrolyte purification by copper arsenite

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ya-jie; XIAO Fa-xin; WANG Yong; LI Chun-hua; XU Wei; JIAN Hong-sheng; MA Yut-ian

    2008-01-01

    Copper electrolyte was purified by copper arsenite that was prepared with As2O3. And electrolysis experiments of purified electrolyte were carried out at 235 and 305 A/m2, respectively. The results show that the yield of copper arsenite is up to 98.64% when the molar ratio of Cu to As is 1.5 in the preparation of copper arsenite. The removal rates of Sb and Bi reach 74.11% and 65.60% respectively after copper arsenite is added in electrolyte. The concentrations of As, Sb and Bi in electrolyte nearly remain constant during electrolysis of 13 d. The appearances of cathode copper obtained at 235 and 305 A/m2 are slippery and even, and the qualification rate is 100% according to the Chinese standard of high-pure cathode copper(GB/T467-97).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-04

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

  7. Differential pulse voltammetric determination of metformin using copper-loaded activated charcoal modified electrode.

    Science.gov (United States)

    Gholivand, Mohammad Bagher; Mohammadi-Behzad, Leila

    2013-07-01

    A simple and sensitive carbon paste electrode has been developed for the electrochemical trace determination of metformin (MET). This sensor was designed by Copper(II)-loaded activated charcoal (Cu-AC) in the carbon paste electrode (CPE), which provides remarkably improved sensitivity and selectivity for the electrochemical stripping assay of MET. The drug was accumulated on the surface of the electrode through formation of a coordination complex with copper ions, which enhanced the sensitivity of the method. The effects of various copper(II) salts and oxidation states of copper (within the carbon paste electrode) on MET oxidation behavior were also investigated. The calibration graph was linear over the concentration range of 50 nM to 60 μM MET, and the detection limit was calculated as 9 nM. The proposed electrode was used successfully for MET determination in real matrices.

  8. The Effect of Copper

    African Journals Online (AJOL)

    higher (p<0.05) in the broodfish fed CSD0 and CSD1 diets than the other diets. Exposure of Clarias gariepinus fish to copper in water, at concentrations above 1.0mg CuSO4/g elicits adverse ... introduction of a toxicant to an aquatic system ..... Toxicity of four commonly used agrochemicals on. Oreochromis niloticus (L) fry.

  9. Quench Press Hardening with Low Copper Plating. Management and Operation of the DoD Instrumented Factory for Gears

    Science.gov (United States)

    2007-11-02

    200 words) Copper plating is used as a carbon stop-off during the carburization and austenitization operations associated with the manufacture of...precision gears. The “Low Copper” project’s goals were to optimize the thickness of copper needed during carburization , and to eliminate the need to re... Carburizing , Copper Plating, SAE/AISI 9310H, Precision Gears, Press Quenching 15. NUMBER OF PAGES 92 16. PRICE CODE 17. SECURITY CLASSIFICATION 18

  10. Presenilin promotes dietary copper uptake.

    Directory of Open Access Journals (Sweden)

    Adam Southon

    Full Text Available 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.

  11. Comparative characteristics of copper, copper chloride, and copper bromide vapor lasers

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-03-01

    The paper reports the results of a comparative study of copper and copper halide vapor lasers emitting in a repetitively-pulsed regime. Copper chloride and copper bromide vapor lasers are found to have identical lasing characteristics under any excitation conditions. These characteristics are different from those of a copper vapor laser. An average lasing power of 13 W has been obtained for all lasers studied for an efficiency of 1%. It is shown that the choice of a laser will largely depend on the laser design suitability for a specific application.

  12. Electrochemical CO2 reduction on Cu2O-derived copper nanoparticles: Controlling the catalytic selectivity of hydrocarbons

    NARCIS (Netherlands)

    Kas, Recep; Kortlever, R.; Milbrat, Alexander; Koper, M.T.M.; Mul, Guido; Baltrusaitis, Jonas

    2014-01-01

    The catalytic activity and hydrocarbon selectivity in electrochemical carbon dioxide (CO2) reduction on cuprous oxide (Cu2O) derived copper nanoparticles is discussed. Cuprous oxide films with [100], [110] and [111] orientation and variable thickness were electrodeposited by reduction of copper(II)

  13. Production of ultrahigh purity copper using waste copper nitrate solution.

    Science.gov (United States)

    Choi, J Y; Kim, D S

    2003-04-25

    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.

  14. Tongling:Copper Industry Giant Takes Shape

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>Centering on the strategic goal of building "World Copper Capital", Tongling constantly extends its product lines and improves the copper industry chain. Now, the copper industry with a production value of RMB 100 billion has taken shape.As the largest copper wire rod manufacturer in Asia, Tongling Quanwei Copper Technologies Co., Ltd., upon its moving into the local market,

  15. A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates.

    Science.gov (United States)

    Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I; Tiwary, ChandraSekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N; Vajtai, Robert; Yu, Aaron Z; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J A; Ajayan, Pulickel M

    2016-12-13

    Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

  16. A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates

    Science.gov (United States)

    Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I.; Tiwary, Chandrasekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N.; Vajtai, Robert; Yu, Aaron Z.; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J. A.; Ajayan, Pulickel M.

    2016-12-01

    Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

  17. Direct Production of Copper

    Science.gov (United States)

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

    1987-09-01

    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.

  18. Biochar and compost as amendments in copper-enriched vineyard soils - stabilization or mobilization of copper?

    Science.gov (United States)

    Soja, Gerhard; Fristak, Vladimir; Wimmer, Bernhard; Bell, Stephen; Chamier Glisczinski, Julia; Pardeller, Georg; Dersch, Georg; Rosner, Franz; Wenzel, Walter; Zehetner, Franz

    2016-04-01

    Copper is an important ingredient for several fungicides that have been used in agriculture. For organic viticulture, several diseases as e.g. downy mildew (Plasmopara viticola) can only be antagonized with Cu-containing fungicides. This long-lasting dependence on Cu-fungicides has led to a gradual Cu enrichment of vineyard soils in traditional wine-growing areas, occasionally exceeding 300 mg/kg. Although these concentrations do not affect the vines or wine quality, they may impair soil microbiological functions in the top soil layer or the root growth of green cover plants. Therefore measures are demanded that reduce the bioavailability of copper, thereby reducing the ecotoxicological effects. The use of biochar and compost as soil amendment has been suggested as a strategy to immobilize Cu and reduce the exchangeable fractions. This study consisted of lab and greenhouse experiments that were designed to test the sorption and desorption behavior of copper in vineyard soils with or without biochar and/or compost as soil amendment. Slightly acidic soils (pHalkaline soils. The analyses of leachate waters of microlysimeter experiments showed that the biochar effects were more evident for a reduction of the ionic form Cu2+ than for total soluble copper, even in alkaline soils. Biochar modified with citric or tartaric acid did not significantly decrease the solubility of copper based on total dissolved concentrations although CEC was higher than in unmodified biochar. Treatments consisting of compost only or that had an equal amount of compost and biochar rather had a mobilizing effect on biochar. Sorption experiments with different DOC concentrations and biochar, however, showed a positive effect on copper sorption. Apparently in vineyard soils the predisposition to form organic-Cu-complexes may outbalance the binding possibilities of these complexes to biochar, occasionally resulting in enhanced mobilization. Presumably immobilization of copper with biochar would

  19. Oxidation Mechanism of Copper Selenide

    Science.gov (United States)

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

    2014-09-01

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

  20. Copper and copper-nickel-alloys - An overview

    Energy Technology Data Exchange (ETDEWEB)

    Klassert, Anton; Tikana, Ladji [Deutsches Kupferinstitut e.V. Am Bonneshof 5, 40474 Duesseldorf (Germany)

    2004-07-01

    With the increasing level of industrialization the demand for and the number of copper alloys rose in an uninterrupted way. Today, the copper alloys take an important position amongst metallic materials due to the large variety of their technological properties and applications. Nowadays there exist over 3.000 standardized alloys. Copper takes the third place of all metals with a worldwide consumption of over 15 millions tons per year, following only to steel and aluminum. In a modern industrial society we meet copper in all ranges of the life (electro-technology, building and construction industry, mechanical engineering, automotive, chemistry, offshore, marine engineering, medical applications and others.). Copper is the first metal customized by humanity. Its name is attributed to the island Cyprus, which supplied in the antiquity copper to Greece, Rome and the other Mediterranean countries. The Romans called it 'ore from Cyprus' (aes cyprium), later cuprum. Copper deposited occasionally also dapper and could be processed in the recent stone age simply by hammering. Already in early historical time copper alloys with 20 to 50 percent tin was used for the production of mirrors because of their high reflecting power. Although the elementary nickel is an element discovered only recently from a historical perspective, its application in alloys - without any knowledge of the alloy composition - occurred at least throughout the last 2.000 years. The oldest copper-nickel coin originates from the time around 235 B.C.. Only around 1800 AD nickel was isolated as a metallic element. In particular in the sea and offshore technology copper nickel alloys found a broad field of applications in piping systems and for valves and armatures. The excellent combination of characteristics like corrosion resistance, erosion stability and bio-fouling resistance with excellent mechanical strength are at the basis of this success. An experience of many decades supports the use

  1. Genesis of Yangla Banded Skarn-Hosted Copper Deposit in Tethys Orogenic Belt of Southwestern China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Yangla copper deposit is the largest banded skarn-hosted copper deposit found recently in the Tethys orogenic belt of Southwestern China. On the basis of the study of distribution, petrology and mineralogy as well as major element, REE and isotope geochemistry, the authors find that the banded skarn, which hosts the deposit, was precipitated from hydrothermal solutions in the form of exhalate sediment. Therefore, the banded skarn-hosted copper deposit is a Sedex-type deposit, with a series of stacked, conformable lenses underlain by at least one stringer zone. The deposit, intercalated at the contact of lower clastic rock and upper carbonate rock of Gajinxueshan Group, was formed in the Carboniferous ((296.1±7.0) Ma), contemporary to the host Gajinxueshan Group. The interpretation of the genesis of Yangla banded skarn-hosted copper deposit is of fundamental exploration significance for the discovery of Sedex-type copper deposit in the region.

  2. Effects of Surface Chemistry on the Generation of Reactive Oxygen Species by Copper Nanoparticles

    Science.gov (United States)

    Shi, Miao; Kwon, Hyun Soo; Peng, Zhenmeng; Elder, Alison; Yang, Hong

    2012-01-01

    Mercaptocarboxylic acids with different carbon chain lengths were used for stabilizing uniform 15 nm copper nanoparticles. The effects of surface chemistry such as ligand type and surface oxidation on the reactive oxygen species (ROS) generated by the copper nanoparticles were examined. Transmission electron microscopy (TEM), Powder X-ray diffraction (PXRD), UV-vis spectroscopy, and an acellular ROS assay show that ROS generation is closely related to the surface oxidation of copper nanoparticles. It was found that the copper nanoparticles with longer chain ligands had surfaces that were better protected from oxidation and a corresponding lower ROS generating capacity than did particles with shorter chain ligands. Conversely, the copper nanoparticles with greater surface oxidation also had higher ROS generating capacity. PMID:22390268

  3. Obtenção e caracterização de carvão ativado de caroço de buriti (Mauritia flexuosa L. f. para a avaliação do processo de adsorção de cobre (II Production and characterization of the activated carbon from buriti stone (Mauritia flexuosa L. f. to evaluate the adsorption's process of copper (II

    Directory of Open Access Journals (Sweden)

    Marcos Vinicios de Souza Pinto

    2013-03-01

    Full Text Available Na região amazônica, algumas indústrias despejam cobre nos corpos receptores que, em elevadas concentrações, é tóxico para os seres vivos. A remoção de cobre de efluentes industriais é realizada por diversos processos como a adsorção. Neste trabalho mostrou-se o resultado da adsorção de cobre (II em carvão ativado de caroço de buriti carbonizado a 400 °C e ativado a 900 °C. O carvão ativado foi caracterizado em termos de área específica, tamanho dos poros, densidades aparente e real, porosidade, microscopia eletrônica de varredura, conteúdo de cinzas, pH, umidade, carbono fixo e grupos funcionais de superfície. O estudo de equilíbrio de adsorção avaliou a influência do diâmetro das partículas do carvão, do tempo de contato adsorvente/adsorbato, do pH e da concentração inicial da solução de cobre (II sobre a remoção de cobre (II. Com base nos resultados, concluiu-se que há uma maior eficiência de remoção de cobre (II para diâmetro In the Amazon region some industries discharges copper into watercourse that in high concentrations is toxic to the biota. The removal of copper from industrial effluent is performed by several processes such as adsorption. This work shows the result of copper (II adsorption on activated carbon obtained from buriti kernel, carbonized at 400 °C and activated at 900 °C. The activated carbon was characterized according to specific area, pore size, apparent and real density, porosity, scanning electron microscopy, ash content, pH, moisture, fixed carbon and surface functional groups. The study of adsorption equilibrium evaluated the influence of the coal particles diameter, contact time adsorbent/adsorbate, pH and copper (II solution initial concentration on copper (II remotion. The results showed a higher removal efficiency of copper (II to the diameter D < 0.595 mm, contact time of 300 minutes, pH of 4.01 and the copper (II initial concentrations of 50 and 80 mg L-1. The

  4. Removal of copper from ferrous scrap

    Science.gov (United States)

    Blander, Milton; Sinha, Shome N.

    1990-01-01

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

  5. Variations of serum copper values in pregnancy

    OpenAIRE

    Vukelić Jelka; Kapamadžija Aleksandra; Petrović Đorđe; Grujić Zorica; Novakov-Mikić Aleksandra; Kopitović Vesna; Bjelica Artur

    2012-01-01

    Introduction. Copper is essential micronutrient and has an important role in the human body. The serum copper increases during pregnancy and is doubled at full term. Lower levels of serum copper in pregnancy are connected with some pathological conditions. Objective. The aim of this study was to estimate the levels of serum copper in normal and pathological pregnancies, comparing them with values of serum copper in non-pregnant women, to determine if serum copper is lower in some pathol...

  6. Nickel, copper and cobalt coalescence in copper cliff converter slag

    Directory of Open Access Journals (Sweden)

    Wolf A.

    2016-01-01

    Full Text Available The aim of this investigation is to assess the effect of various additives on coalescence of nickel, copper and cobalt from slags generated during nickel extraction. The analyzed fluxes were silica and lime while examined reductants were pig iron, ferrosilicon and copper-silicon compound. Slag was settled at the different holding temperatures for various times in conditions that simulated the industrial environment. The newly formed matte and slag were characterized by their chemical composition and morphology. Silica flux generated higher partition coefficients for nickel and copper than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and corresponding partition coefficients than fluxes. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with some minute traces of magnetite as the secondary phase. Addition of 5 wt% of pig iron, ferrosilicon and copper-silicon alloys favored the formation of a metallized matte which increased Cu, Ni and Co recoveries. Addition of copper-silicon alloys with low silicon content was efficient in copper recovery but coalescence of the other metals was low. Slag treated with the ferrosilicon facilitated the highest cobalt recovery while copper-silicon alloys with silicon content above 10 wt% resulted in high coalescence of nickel and copper, 87 % and 72 % respectively.

  7. Study of Copper Substitute in High Copper Price Market Environment

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>The high price of copper drives up industry cost,also it is difficult for terminal products to raise price to transfer the cost pressure brought by increase in copper price,as a result downstream consumption markets instead try to seek

  8. Fixation Property of Copper Triazole Wood Preservatives

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    According to AWPA E11-2006 standard,copper fixation rates of several copper-based formulations,such as ammoniacal copper,amine copper,and ammoniacal-ethanolamine copper,as well as alkaline copper quaternary(ACQ),were tested and compared in this paper.And the fixation rates of tebuconazole(TEB) and propiconazole(PPZ) in several formulations,such as copper azole,emulsified type and solvent type,were also compared.The determination of copper content in the leachate was analyzed by atomic absorption spectrom...

  9. INTERACTION OF COPPER BASED PRESERVATIVES WITH WOOD

    Directory of Open Access Journals (Sweden)

    Ali Temiz

    2004-11-01

    Full Text Available Copper is highly toxic to fungi and the element is widely used in many preservative formulations over 50 years. The interactions of wood and copper-based preservatives impact both the performance and the environment aspects of treated wood. Copper might be present in treated wood as coppercellulose complex, copper-lignin complex, and crystalline or amorphous inorganic/organic copper compounds. In this review; it was aimed to investigate the interactions of wood and copper-based preservatives, Copper Adsorpsion factors and copper forms in treated wood

  10. Copper Nanoparticles for Printed Electronics: Routes Towards Achieving Oxidation Stability.

    Science.gov (United States)

    Magdassi, Shlomo; Grouchko, Michael; Kamyshny, Alexander

    2010-09-08

    In the past few years, the synthesis of Cu nanoparticles has attracted much attention because of its huge potential for replacing expensive nano silver inks utilized in conductive printing. A major problem in utilizing these copper nanoparticles is their inherent tendency to oxidize in ambient conditions. Recently, there have been several reports presenting various approaches which demonstrate that copper nanoparticles can resist oxidation under ambient conditions, if they are coated by a proper protective layer. This layer may consist of an organic polymer, alkene chains, amorphous carbon or graphenes, or inorganic materials such as silica, or an inert metal. Such coated copper nanoparticles enable achieving high conductivities by direct printing of conductive patterns. These approaches open new possibilities in printed electronics, for example by using copper based inkjet inks to form various devices such as solar cells, Radio Frequency Identification (RFID) tags, and electroluminescence devices. This paper provides a review on the synthesis of copper nanoparticles, mainly by wet chemistry routes, and their utilization in printed electronics.

  11. Copper Nanoparticles for Printed Electronics: Routes Towards Achieving Oxidation Stability

    Directory of Open Access Journals (Sweden)

    Shlomo Magdassi

    2010-09-01

    Full Text Available In the past few years, the synthesis of Cu nanoparticles has attracted much attention because of its huge potential for replacing expensive nano silver inks utilized in conductive printing. A major problem in utilizing these copper nanoparticles is their inherent tendency to oxidize in ambient conditions. Recently, there have been several reports presenting various approaches which demonstrate that copper nanoparticles can resist oxidation under ambient conditions, if they are coated by a proper protective layer. This layer may consist of an organic polymer, alkene chains, amorphous carbon or graphenes, or inorganic materials such as silica, or an inert metal. Such coated copper nanoparticles enable achieving high conductivities by direct printing of conductive patterns. These approaches open new possibilities in printed electronics, for example by using copper based inkjet inks to form various devices such as solar cells, Radio Frequency Identification (RFID tags, and electroluminescence devices. This paper provides a review on the synthesis of copper nanoparticles, mainly by wet chemistry routes, and their utilization in printed electronics.

  12. 江西省兴源冲铜矿床同位素地球化学特征及成矿机制探讨%Carbon, oxygen and sulfur isotopic geochemistry and metallogenic mechanism of Xingyuanchong copper deposit in Jiangxi Province

    Institute of Scientific and Technical Information of China (English)

    刘婷; 刘成东; 严兆彬; 陈益平; 吴旭铃; 凡秀君

    2013-01-01

    The Xingyuanchong copper deposit of Huangmao area is located in the west segment of the South Jiuling large copper polymetallic ore concentration area.In combination with the metallogenic characteristics of the ore deposit,the authors mainly studied stable isotopes of the ores to probe into the sources of metallogenic materials and metallogenic mechanism of the deposit.δ13 CVPDB values of carbonates in this area vary in the range of -5.4‰~1.9‰,0.6‰ on average,whereas δ18OsMow values range from 9.0‰ to 13.8‰,10.9‰ on average,indicating that carbonates were mainly marine carbonates.The δ18O-δ13C diagram shows that carbon in the region probably came from the deep earth,and experienced metamorphism at high temperatures and alteration at low temperatures.Except two higher values of δ34S,most δ34S values in this deposit vary in the range of 1.0‰ ~6.2‰ ; in comparison with other similar deposits,sulfur of this deposit is characterized by submarine exhalation sedimentation and hydrothermal superimposition.In combination with isotopic data and geological setting,it is proposed that the ore-forming processes of the Xingyuanchong copper deposit could be divided into two stages.At the first stage,submarine volcanic sediments or protore layers were formed in Mesoproterozoic.At the second stage,the pre-existing protores were altered by the hydrothermal fluids and dynamic metamorphism mainly derived from Jinning orogenic period in Late Proterozoic.%兴源冲铜矿床地处九岭南缘铜多金属大型矿集区西段的黄茅地区.文章在成矿地质特征的基础上,通过对矿石进行稳定同位素地球化学研究,重点分析了成矿物质来源,探讨了矿床成矿机制.碳、氧同位素分析结果表明,矿区碳酸盐岩δ13 CVPDB为-5.4‰~ 1.9‰,平均为0.6‰,δ18 OSMOW变化范围为9.0‰~13.9‰,平均为10.9‰,主要为海相碳酸盐岩,碳、氧同位素图解表明碳可能主要来源于深部,且受高温变质作

  13. Electroleaching of Copper Waste with Recovery of Copper by Electrodialysis

    Directory of Open Access Journals (Sweden)

    Nuñez P.

    2013-04-01

    Full Text Available A new process to leach and recover copper from solid waste using electric fields was designed. The leaching with electro migration is presented as an alternative to traditional leaching. Preliminary data indicate that the copper ion migration is facilitated by using the electrical potential difference; therefore applying a potential difference in the processes of leaching facilitates the removal of copper. This is especially useful when mineral concentrations are very low. Different phenomena associated with transport of copper in solution are studied to generate a model able predict the state of the copper ion concentration in time. A kinetic model for the process was developed and fitted very well the experimental data.

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

    Science.gov (United States)

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

    2011-07-01

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

  15. Investigation of the chemical and electrochemical phenomena in the chemical mechanical planarization of copper

    Science.gov (United States)

    Wang, Ling

    uncoupled copper, tantalum and titanium electrodes were obtained in commercial slurry and solutions containing hydrogen peroxide and glycine, for assessing the polarity between copper and tantalum when forming a galvanic couple, as function of peroxide concentrations, solution pHs, and the impact of diluting the slurry on the galvanic interaction. Galvanic currents and mixed corrosion potentials were measured in tantalum-copper couples formed by short-circuiting the two specimen electrodes in a three-electrode cell through a potentiostat-based zero resistance ammeter, to verify the correlation between the polarity and the galvanic interactions and to assess the effects of solution composition and the tantalum-to-copper surface area ratio. The results showed that the material removal due to galvanic interaction under non-polishing conditions is negligibly small, but could be a potential issue during CMP, and either copper or tantalum barrier material could experience accelerated corrosion, depending on the solution composition. The galvanic interaction between copper and tantalum is sensitive to the solution composition. Acidic acetate/acetic acid buffer may transiently accelerate the galvanic corrosion of copper, while basic carbonate/bicarbonate buffer may transiently accelerate the galvanic corrosion of tantalum. Glycine promotes galvanic corrosion of copper. Hydrogen peroxide is the most effective component to exacerbate galvanic corrosion between copper and tantalum, with tantalum experiencing accelerated corrosion. Changing the surface area of tantalum, which has the more active corrosion, has a less significant effect on the galvanic corrosion than changing the surface areas of the copper, which has a more noble potential.

  16. Studies of copper transport in mammalian cells using copper radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Camakaris, J.; Voskoboinik, I.; Brooks, H.; Greenough, M. [University of Melbourne, Parkville, VIC (Australia). Department of Genetics; Smith, S. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia). Radiopharmaceuticals Division; Mercer, J. [Deakin University, Clayton, VIC (Australia). Centre of Cellular and Molecular Biology

    1998-12-31

    The trace element copper poses a major problem for all organisms. It is essential as a number of vital enzymes require it. Copper deficiency can lead to neurological disorders, osteoporosis and weakening of arteries. However Cu is also highly toxic and homeostatic mechanisms have evolved to maintain Cu at levels which satisfy requirements but do not cause toxicity. Toxicity is mediated by the oxidative capacity of Cu and its ability to generate toxic free radicals. There are several acquired and inherited diseases due to either Cu toxicity or Cu deficiency. The study of these diseases facilitates identification of genes and proteins involved in copper homeostasis, and this in turn will provide rational therapeutic approaches. Using the copper radioisotopes {sup 64}Cu (t1/2 = 12.8 hr) and {sup 67}Cu (t1/2 = 61 hr) we have developed a number of systems for studying copper transport in mammalian cells. These include investigation of copper uptake, copper efflux and ligand blot assays for Cu-binding proteins. Our studies have focused on Menkes disease which is an inherited and usually lethal copper deficiency disorder in humans. We have demonstrated that the Menkes protein is directly involved as a copper efflux pump in mammalian cells. Using cells overexpressing the Menkes protein we have provided the first biochemical evidence that this functions as a Cu translocating (across the membrane) P-type ATPase (Voskoboinik et al., FEBS Letters, in press). These studies were carried out using purified plasma membrane vesicles. We are now carrying out structure- function studies on this protein using targeted mutations and assaying using the radiocopper vesicle assay. Recently we have commenced studies on the role of amyloid precursor protein (APP) in copper transport and relationship of this to Alzheimers disease

  17. Multimetallic Electrodeposition on Carbon Fibers

    Science.gov (United States)

    Böttger-Hiller, F.; Kleiber, J.; Böttger, T.; Lampke, T.

    2016-03-01

    Efficient lightweight design requires intelligent materials that meet versatile functions. One approach is to extend the range of properties of carbon fiber reinforced plastics (CFRP) by plating the fiber component. Electroplating leads to metalized layers on carbon fibers. Herein only cyanide-free electrolytes where used. Until now dendrite-free layers were only obtained using current densities below 1.0 A dm-2. In this work, dendrite-free tin and copper coatings were achieved by pre-metalizing the carbon fiber substrates. Furthermore, applying a combination of two metals with different sized thermal expansion coefficient lead to a bimetallic coating on carbon fiber rovings, which show an actuatory effect.

  18. Effects of past copper contamination and soil structure on copper leaching from soil

    DEFF Research Database (Denmark)

    Paradelo, M; Møldrup, Per; Arthur, Emmanuel

    2013-01-01

    Copper contamination affects biological, chemical, and physical soil properties and associated ecological functions. Changes in soil pore organization as a result of Cu contamination can dramatically affect flow and contaminant transport in polluted soils. This study assessed the influence of soil......, and dissolved organic carbon (DOC) and Cu losses. The 5% arrival time (t0.05) and apparent dispersivity (λapp) for tracer breakthrough were calculated by fitting the experimental data to a nonparametric, double-lognormal probability density function. Soil bulk density, which did not follow the Cu gradient...

  19. The copper recovery from cupric oxide catalysts by plasma reduction process

    Energy Technology Data Exchange (ETDEWEB)

    Imris, I.; Klenovcanova, A. [Technical Univ. of Kosice, Kosice (Slovakia). Dept. of Power Engineering

    2007-07-01

    A plasma reduction process was used to recover copper from cupric oxide catalysts. Two types of plasma reduction smelting tests were conducted to verify the thermodynamic calculations. The plasma reactor consisted of a cylindrical steel shell lined with a castable alumina and a graphite crucible. Cupric oxide catalyst ESM 461 was mixed with stoichiometric amounts of carbon reductant and a 10 per cent addition of calcium oxide flux. Results of the experimental tests and the thermodynamic analysis showed that the copper can be extracted from cupric oxide using the plasma reduction process. Copper recovery was limited by physico-chemical copper losses. Copper oxide solubility was relatively high, so that copper recovery was low in their first series of plasma tests. The addition of calcium oxide flux improved copper recovery rates when dicalcium silicate was formed in the slag. The offgas samples indicated that concentrations of carbon monoxide (CO) in the gas phase was very high. It was concluded that the process is both commercially feasible and does not produce liquid or solid wastes. 7 refs., 2 tabs., 4 figs.

  20. A Plasmodium falciparum copper-binding membrane protein with copper transport motifs

    OpenAIRE

    Choveaux David L; Przyborski Jude M; Goldring JP

    2012-01-01

    Abstract Background Copper is an essential catalytic co-factor for metabolically important cellular enzymes, such as cytochrome-c oxidase. Eukaryotic cells acquire copper through a copper transport protein and distribute intracellular copper using molecular chaperones. The copper chelator, neocuproine, inhibits Plasmodium falciparum ring-to-trophozoite transition in vitro, indicating a copper requirement for malaria parasite development. How the malaria parasite acquires or secretes copper st...

  1. Effects of dissolved and complexed copper on heterotrophic bacterial production in San Diego bay.

    Science.gov (United States)

    Boyd, Thomas J; Wolgast, David M; Rivera-Duarte, Ignacio; Holm-Hansen, Osmund; Hewes, Christopher D; Zirino, Alberto; Chadwick, D Bart

    2005-04-01

    Bacterial abundance and production, free (uncomplexed) copper ion concentration, total dissolved copper concentration, dissolved organic carbon (DOC), total suspended solids (TSS), and chlorophyll a were measured over the course of 1 year in a series of 27 sample "Boxes" established within San Diego Bay. Water was collected through a trace metal-clean system so that each Box's sample was a composite of all the surface water in that Box. Bacterial production, chlorophyll a, TSS, DOC, and dissolved copper all generally increased from Box 1 at the mouth of the Bay to Box 27 in the South or back Bay. Free copper ion concentration generally decreased from Box 1 to Box 27 presumably due to increasing complexation capacity within natural waters. Based on correlations between TSS, chlorophyll a, bacterial production or DOC and the ratio of dissolved to free Cu ion, both DOC and particulate (bacteria and algae) fractions were potentially responsible for copper complexation, each at different times of the year. CuCl2 was added to bacterial production assays from 0 to 10 microg L(-1) to assess acute copper toxicity to the natural microbial assemblage. Interestingly, copper toxicity appeared to increase with decreases in free copper from the mouth of the Bay to the back Bay. This contrasts the free-ion activity model in which higher complexation capacity should afford greater copper protection. When cell-specific growth rates were calculated, faster growing bacteria (i.e. toward the back Bay) appeared to be more susceptible to free copper toxicity. The protecting effect of natural dissolved organic material (DOM) concentrated by tangential flow ultrafiltration (>1 kDa), illite and kaolinite minerals, and glutathione (a metal chelator excreted by algae under copper stress) was assessed in bacterial production assays. Only DOM concentrate offered any significant protection to bacterial production under increased copper concentrations. Although the potential copper protecting

  2. Nanocrystalline copper based microcomposites

    OpenAIRE

    J.P. Stobrawa; Z.M. Rdzawski; W. Głuchowski; J. Domagała-Dubiel

    2012-01-01

    Purpose: The aim of this work was to investigate microstructure, mechanical properties and deformation behavior of copper microcomposites: Cu- Y2O3, Cu- ZrO2 and Cu-WC produced by powder metallurgy techniques.Design/methodology/approach: Tests were made with Cu-Y2O3, Cu-ZrO2 and Cu-WC microcomposites containing up to 2% of a strengthening phase. The materials were fabricated by powder metallurgy techniques, including milling of powders, followed by their compacting and sintering. The main mec...

  3. The Bauschinger Effect in Copper

    DEFF Research Database (Denmark)

    Pedersen, Ole Bøcker; Brown, L .M.; Stobbs, W. M.

    1981-01-01

    A study of the Bauschinger effect in pure copper shows that by comparison with dispersion hardened copper the effect is very small and independent of temperature. This suggests that the obstacles to flow are deformable. A simple composite model based on this principle accounts for the data semi...

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

    Science.gov (United States)

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

    2007-08-01

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

  5. Effect of process parameters on coating composition of cathodic-plasma-electrolysis-treated copper

    Indian Academy of Sciences (India)

    ASIYEH HABIBI; S MOHAMMAD MOUSAVI KHOIE; FARZAD MAHBOUBI; MUSTAFA URGEN

    2017-04-01

    Cathodic plasma electrolysis is a novel technique to form nanostructured layers on metallic surfaces by application of high voltage in a suitable aqueous electrolyte. In the present study, copper is treated by plasma electrolysisin 50 vol% ethanol electrolyte and coatings comprising carbon nanostructure and copper oxide are formed on the copper. The effect of some process parameters such as electrical conductivity, volume and temperature of electrolyte and ratio of anode to cathode surface area on current–voltage behaviour and subsequently coating compositions are investigated at 150V deposition voltage. The composition and morphology of these coatings are characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Different current–voltage behaviours, temperatures of substrate and the contents and energies of radicals and ions around the substrate by changes in the mentioned parameters cause different compositions from 100 vol% copper oxide to different ratios of copper oxide to carbon, the structure changing from amorphous to graphitic structure in carbon and amorphous to cubic morphology in copper oxide on the substrate. Therefore, the understanding of cathodic plasma electrolysiscan be developed.

  6. Copper: From neurotransmission to neuroproteostasis

    Directory of Open Access Journals (Sweden)

    Carlos M Opazo

    2014-07-01

    Full Text Available Copper is critical for the Central Nervous System (CNS development and function. In particular, different studies have shown the effect of copper at brain synapses, where it inhibits Long Term Potentation (LTP and receptor pharmacology. Paradoxically, according to recent studies copper is required for a normal LTP response. Copper is released at the synaptic cleft, where it blocks glutamate receptors, which explain its blocking effects on excitatory neurotransmission. Our results indicate that copper also enhances neurotransmission through the accumulation of PSD95 protein, which increase the levels of AMPA receptors located at the plasma membrane of the post-synaptic density. Thus, our findings represent a novel mechanism for the action of copper, which may have implications for the neurophysiology and neuropathology of the CNS. These data indicate that synaptic configuration is sensitive to transient changes in transition metal homeostasis. Our results suggest that copper increases GluA1 subunit levels of the AMPA receptor through the anchorage of AMPA receptors to the plasma membrane as a result of PSD-95 accumulation. Here, we will review the role of copper on neurotransmission of CNS neurons. In addition, we will discuss the potential mechanisms by which copper could modulate neuronal proteostasis (neuroproteostasis in the CNS with focus in the Ubiquitin Proteasome System, which is particularly relevant to neurological disorders such Alzheimer’s disease (AD where copper and protein dyshomeostasis may contribute to neurodegeneration. An understanding of these mechanisms may ultimately lead to the development of novel therapeutic approaches to control metal and synaptic alterations observed in AD patients.

  7. Field-based evidence for consistent responses of bacterial communities to copper contamination in two contrasting agricultural soils

    Directory of Open Access Journals (Sweden)

    Jing eLi

    2015-02-01

    Full Text Available Copper contamination on China’s arable land could pose severe economic, ecological and healthy consequences in the coming decades. As the drivers in maintaining ecosystem functioning, the responses of soil microorganisms to long-term copper contamination in different soil ecosystems are still debated. This study investigated the impacts of copper gradients on soil bacterial communities in two agricultural fields with contrasting soil properties. Our results revealed consistent reduction in soil microbial biomass carbon (SMBC with increasing copper levels in both soils, coupled by significant declines in bacterial abundance in most cases. Despite of contrasting bacterial community structures between the two soils, the bacterial diversity in the copper-contaminated soils showed considerably decreasing patterns when copper levels elevated. High-throughput sequencing revealed copper selection for major bacterial guilds, in particular, Actinobacteria showed tolerance, while Acidobacteria and Chloroflexi were highly sensitive to copper. The thresholds that bacterial communities changed sharply were 800 and 200 added copper mg kg-1 in the fluvo-aquic soil and red soil, respectively, which were similar to the toxicity thresholds (EC50 values characterized by SMBC. Structural equation model (SEM analysis ascertained that the shifts of bacterial community composition and diversity were closely related with the changes of SMBC in both soils. Our results provide field-based evidence that copper contamination exhibits consistently negative impacts on soil bacterial communities, and the shifts of bacterial communities could have largely determined the variations of the microbial biomass.

  8. Determination of an organic-acid analog of DOC for use in copper toxicity studies on salmonids

    Energy Technology Data Exchange (ETDEWEB)

    MacRae, R.K.; Meyer, J.S.; Hansen, J.A.; Bergman, H.L. [Univ. of Wyoming, Laramie, WY (United States); Maest, A.; Marr, J.; Beltman, D.; Lipton, J. [Hagler Bailly, Inc., Boulder, CO (United States)

    1995-12-31

    Concentrations of dissolved copper in streams draining mine sites often exceed concentrations shown to cause acute and chronic mortality in salmonids. However, toxicity and impaired behaviors may be modified by dissolved organic carbon (DOC) and other inorganic components present in the site water. The effects of DOC on copper speciation, and thus bioavailability and toxicity, were determined by titrating stream waters with copper, using a cupric ion-specific electrode to detect free copper concentrations. Effects of various competing cations (e.g., Ca{sup +2}, Co{sup +2}) on copper-DOC binding were also evaluated. Titration results were evaluated using Scatchard and non-linear regression analyses to quantify the strength and capacity of copper-DOC binding. Inorganic speciation was determined using the geochemical model MINEQL{sup +}. Results of these titrations indicated the presence of two or three distinct copper binding components in site water DOC. Three commercially available organic acids where then chosen to mimic the binding characteristics of natural DOC. This DOC-analog was used successfully in fish toxicity studies to evaluate the influence of DOC on copper bioavailability. Geochemical models were developed to predict copper speciation in both laboratory test waters and site waters, for any typical combination of water chemistry parameters (pH, alkalinity, [DOC], etc.). A combined interpretation of fish toxicity and modeling results indicate that some DOC-bound copper was bioavailable.

  9. Field-based evidence for consistent responses of bacterial communities to copper contamination in two contrasting agricultural soils.

    Science.gov (United States)

    Li, Jing; Ma, Yi-Bing; Hu, Hang-Wei; Wang, Jun-Tao; Liu, Yu-Rong; He, Ji-Zheng

    2015-01-01

    Copper contamination on China's arable land could pose severe economic, ecological and healthy consequences in the coming decades. As the drivers in maintaining ecosystem functioning, the responses of soil microorganisms to long-term copper contamination in different soil ecosystems are still debated. This study investigated the impacts of copper gradients on soil bacterial communities in two agricultural fields with contrasting soil properties. Our results revealed consistent reduction in soil microbial biomass carbon (SMBC) with increasing copper levels in both soils, coupled by significant declines in bacterial abundance in most cases. Despite of contrasting bacterial community structures between the two soils, the bacterial diversity in the copper-contaminated soils showed considerably decreasing patterns when copper levels elevated. High-throughput sequencing revealed copper selection for major bacterial guilds, in particular, Actinobacteria showed tolerance, while Acidobacteria and Chloroflexi were highly sensitive to copper. The thresholds that bacterial communities changed sharply were 800 and 200 added copper mg kg(-1) in the fluvo-aquic soil and red soil, respectively, which were similar to the toxicity thresholds (EC50 values) characterized by SMBC. Structural equation model (SEM) analysis ascertained that the shifts of bacterial community composition and diversity were closely related with the changes of SMBC in both soils. Our results provide field-based evidence that copper contamination exhibits consistently negative impacts on soil bacterial communities, and the shifts of bacterial communities could have largely determined the variations of the microbial biomass.

  10. Copper-mercury film electrode for cathodic stripping voltammetric determination of Se(IV).

    Science.gov (United States)

    Sladkov, Vladimir; David, François; Fourest, Blandine

    2003-01-01

    The copper-mercury film electrode has been suggested for the determination of Se(IV) in a wide range of concentration from 1x10(-9) to 1x10(-6) mol L(-1)by square-wave cathodic stripping voltammetry. Insufficient reproducibility and sensitivity of the mercury film electrode have been overcome by using copper(II) ions during the plating procedure. Copper(II) has been found to be reduced and form a reproducible copper-mercury film on a glassy carbon electrode surface. The plating potential and time, the concentration of copper(II) and the concentration of the supporting electrolyte have been optimised. Microscopy has been used for a study of the morphology of the copper-mercury film. It has been found that it is the same as for the mercury one. The preconcentration step consists in electrodeposition of copper selenide on the copper-mercury film. The relative standard deviation is 4.3% for 1x10(-6) mol L(-1) of Se(IV). The limit of detection is 8x10(-10) mol L(-1) for 5 min of accumulation.

  11. Chemosensory deprivation in juvenile coho salmon exposed to dissolved copper under varying water chemistry conditions.

    Science.gov (United States)

    McIntyre, Jenifer K; Baldwin, David H; Meador, James P; Scholz, Nathaniel L

    2008-02-15

    Dissolved copper is an important nonpoint source pollutant in aquatic ecosystems worldwide. Copper is neurotoxic to fish and is specifically known to interfere with the normal function of the peripheral olfactory nervous system. However,the influence of water chemistry on the bioavailability and toxicity of copper to olfactory sensory neurons is not well understood. Here we used electrophysiological recordings from the olfactory epithelium of juvenile coho salmon (Oncorhynchus kisutch) to investigate the impacts of copper in freshwaters with different chemical properties. In low ionic strength artificial fresh water, a short-term (30 min) exposure to 20 microg/L dissolved copper reduced the olfactory response to a natural odorant (10(-5) M L-serine) by 82%. Increasing water hardness (0.2-1.6 mM Ca) or alkalinity (0.2-3.2 mM HCO3-) only slightly diminished the inhibitory effects of copper. Moreover, the loss of olfactory function was not affected by a change in pH from 8.6 to 7.6. By contrast, olfactory capacity was partially restored by increasing dissolved organic carbon (DOC; 0.1-6.0 mg/L). Given the range of natural water quality conditions in the western United States, water hardness and alkalinity are unlikelyto protect threatened or endangered salmon from the sensory neurotoxicity of copper. However, the olfactory toxicity of copper may be partially reduced in surface waters that have a high DOC content.

  12. Carbon thin films deposited by the magnetron sputtering technique using cobalt, copper and nickel as buffer-layers; Filmes finos de carbono depositados por meio da tecnica de magnetron sputtering usando cobalto, cobre e niquel como buffer-layers

    Energy Technology Data Exchange (ETDEWEB)

    Costa e Silva, Danilo Lopes

    2015-11-01

    In this work, carbon thin films were produced by the magnetron sputtering technique using single crystal substrates of alumina c-plane (0001) and Si (111) and Si (100) substrates, employing Co, Ni and Cu as intermediate films (buffer-layers). The depositions were conducted in three stages, first with cobalt buffer-layers where only after the production of a large number of samples, the depositions using cooper buffer-layers were carried out on Si substrates. Then, depositions were performed with nickel buffer layers using single-crystal alumina substrates. The crystallinity of the carbon films was evaluated by using the technique of Raman spectroscopy and, then, by X-ray diffraction (XRD). The morphological characterization of the films was performed by scanning electron microscopy (SEM and FEG-SEM) and high-resolution transmission electron microscopy (HRTEM). The XRD peaks related to the carbon films were observed only in the results of the samples with cobalt and nickel buffer-layers. The Raman spectroscopy showed that the carbon films with the best degree of crystallinity were the ones produced with Si (111) substrates, for the Cu buffers, and sapphire substrates for the Ni and Co buffers, where the latter resulted in a sample with the best crystallinity of all the ones produced in this work. It was observed that the cobalt has low recovering over the alumina substrates when compared to the nickel. Sorption tests of Ce ions by the carbon films were conducted in two samples and it was observed that the sorption did not occur probably because of the low crystallinity of the carbon films in both samples. (author)

  13. Copper anode corrosion affects power generation in microbial fuel cells

    KAUST Repository

    Zhu, Xiuping

    2013-07-16

    Non-corrosive, carbon-based materials are usually used as anodes in microbial fuel cells (MFCs). In some cases, however, metals have been used that can corrode (e.g. copper) or that are corrosion resistant (e.g. stainless steel, SS). Corrosion could increase current through galvanic (abiotic) current production or by increasing exposed surface area, or decrease current due to generation of toxic products from corrosion. In order to directly examine the effects of using corrodible metal anodes, MFCs with Cu were compared with reactors using SS and carbon cloth anodes. MFCs with Cu anodes initially showed high current generation similar to abiotic controls, but subsequently they produced little power (2 mW m-2). Higher power was produced with microbes using SS (12 mW m-2) or carbon cloth (880 mW m-2) anodes, with no power generated by abiotic controls. These results demonstrate that copper is an unsuitable anode material, due to corrosion and likely copper toxicity to microorganisms. © 2013 Society of Chemical Industry.

  14. Jiangxi Copper Corporation Builds 900,000-Ton Copper Production Capacity

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>The Eastward Refined Copper Expansion Pro- ject of Guixi Smelting Plant under Jiangxi Copper Corporation has output its first lot of Copper cathode,marking the company’s pos- session of a 900,000-ton copper production ca- pacity.Thus the company further strengthens its position as the top 3 of the copper world.

  15. Secondary Copper Industry Entered Rapid Growth Period

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    In China’s copper output,secondary copper accounts for about 40%,for power cable industry,the usage percentage of secondary copper is about 50%.Under the favorable policy of the government to vigorously support recycling industry,secondary copper rod enterprises begin to expand,and are confident toward the industry’s potentials.

  16. Unravelling the Chemical Nature of Copper Cuprizone

    OpenAIRE

    Messori, L.; Casini, A.; C.Gabbiani; Sorace, L.; Muniz-Miranda, M.; Zatta, P

    2007-01-01

    During the last 50 years, formation of the highly chromogenic copper cuprizone complex has been exploited for spectrophotometric determinations of copper although the precise chemical nature of the resulting species has never been ascertained; we eventually show here, in contrast to current opinion, that copper cuprizone is a copper(III) complex.

  17. Corrosion of the copper canister in the repository environment

    Energy Technology Data Exchange (ETDEWEB)

    Hermansson, H.P.; Eriksson, Sture [Studsvik Material AB, Nykoeping (Sweden)

    1999-12-01

    there is probably a chloride induced passivation mechanism slowing down such pitting in the long run. A mechanism for this is proposed here. A special family of local attacks, based on the growth of sulphide, oxide/hydroxide and even carbonate/malachite whiskers, could also happen in the repository. It has been demonstrated in the experimental part of this work that whiskers can grow on copper in repository related environments containing sulphide. The chemical composition of such whiskers and their growth mechanism is treated in the present work. The integrity related consequences for the copper substrate on which they grow still remains, however, to be investigated.

  18. Secondary Copper Consumption and Location in China

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> China is short of copper resources and is alsothe second largest copper consuming country inthe world.The way to overcome the contradic-tion between the resource shortage and fastgrowth in consumption is to import copper rawmaterial in large quantities.Since the 1990’s,China’s import quantity of copper scrap hasincreased considerably.During the last twoyears,China has imported copper scrap worthof US$2.25 billion,1.32 times of the value ofimported copper concentrates in the same pe-riod.China is one of the biggest copper scrap

  19. Thin films of copper oxide and copper grown by atomic layer deposition for applications in metallization systems of microelectronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Waechtler, Thomas

    2010-05-25

    electrochemical copper deposition, the combination of ALD copper and ruthenium proves advantageous, especially with respect to the quality of the electroplated films and their filling behavior in interconnect structures. Furthermore, the ALD process developed also bears potential for an integration with carbon nanotubes. (orig.)

  20. Reduction and Oxidation of Copper Oxide Thin Films and Thermal Stability Issues in Copper-Based Metallization.

    Science.gov (United States)

    Li, Jian

    This thesis investigates the oxidation and reduction of Cu-oxides and thermal induced reactions of Cu with metals. The combination of ^{16}O( alpha,alpha)^{16}O oxygen resonance and transmission electron microscopy (TEM) provides an effective method of studying the oxidation and reduction of copper oxide thin films. A discontinuous morphology of grain growth of Cu_2O in found in the CuO matrix during reduction. The migration of the Cu_2O-CuO phase boundary is induced by oxygen diffusion along the moving boundary. Grain growth is the dominant process in the transformation from CuO to Cu_2O; nucleation is the dominant process in the reverse transformation, i.e. from Cu_2O to CuO. The reduction and oxidation of copper oxides are asymmetrical; the latter is significantly faster. The metastable phase Cu _4O_3 was formed by ion milling CuO. Carbon and refractory metals such as Ti or Zr can enhance the reduction rate of CuO. Three topics relating to thermal stability issues in Cu-based metallization were investigated: (1) texturing in electroless copper films on epitaxial copper seed layers; (2) predicting first phase formation in Cu/metal bilayer structures; and (3) encapsulation of Cu fine line structures with TiN. (100)- and (111)-textured copper layers were deposited by electroless plating on copper seed layers grown epitaxially on Si (100) and Si (111) substrates, respectively. (111) -textured copper films are more oxidation-resistant. Rutherford backscattering spectrometry (RBS) and in situ transmission electron microscopy (TEM) were used to determine phase formation in Cu-M (M = Ti, Zr, Mg, Sb, Pd and Pt) bilayer systems. An effective heat of formation rule was employed to predict first phase formation in these systems. A TiN-encapsulated copper structure was made by annealing a Cu-10at%Ti alloy film evaporated on a SiO _2/Si(100) substrate at 550^ circC in an NH_3 ambient. Fast heating rates (70^circC/min.) to 550^circC can effectively suppress the formation of Cu

  1. An Introduction to Copper Deposits in China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    There are 11 genetic types of copper deposit in China, three of which (porphyry,contact metasomatic and VMS types) are the most important. The copper deposits distribute widely both temporally and spatially in China. The features of copper ores in China are mostly poor in copper tenor and complex in metal associated. The copper metallogeny in China predominantly occurs in three metallogenic megadomains, namely the circum-Pacific, the paleo-Asian and the Tethys-Himalayan.

  2. Fluid inclusion and carbon oxygen isotope studies of Qiongbulake copper deposit in Awulale Mountains, Xinjiang%阿吾拉勒山琼布拉克铜矿床流体包裹体及碳氧同位素研究

    Institute of Scientific and Technical Information of China (English)

    罗勇; 廖思平; 杨武斌; 单强; 周昌平

    2011-01-01

    Located in Yining County of Xinjiang, the Qiongbulake copper deposit was formed in relation to magmatic hydrothermal fluids. These fluids formed a stockwork of calcite veinlets. The distribution of veins and fluid inclusions in these veins records the progressive pressure, temperature, and compositional evolution of the hydrothermal fluids that formed this copper deposit. This paper aims to characterize the temporal and spatial evolution of the mineralizing system and to understand the mechanism that controlled the accumulation of this large, massive Cu deposit. On the basis of the studies by means of inclusion petrography, microthermometry and carbon, oxygen stable isotope, the authors systematically studied characteristics of the ore-forming fluids and the origin of the Qiongbulake copper deposit. Three types of fluid inclusions in calcite were recognized, I.e., VLtype inclusions, Lva type inclusions and LVb type inclusions, with no CO2 phrase fluid inclusions and daughter phrase fluid inclusions. Fluid inclusions associated with calcite display moderate-low homogenization temperature (92.3~ 355.91C ), moderate-low salinities (ωCNaClep) 0.88% ~ 16.89%) and low density (0.62~1.04g/cm3). C and O isotope determinations of calcite show δ 13Cpdb values of - 7.37‰~-4.19‰ and δ Osmowvalues of 9.63‰ ~ 11.91‰, suggesting that the ore-forming fluids were derived from the mantle and volcanism. On the whole, the Qiongbulake copper deposit is a moderate-low hydrothermal ore deposit.%琼布拉克铜矿床位于新疆伊宁县境内,前人对该矿床的成因一直存在争议.文章通过对琼布拉克铜矿床方解石中的流体包裹体进行系统的岩相学、显微测温学和碳氧稳定同位素分析研究,探讨了成矿流体的来源及演化.研究表明:琼布拉克铜矿床的流体包裹体主要为气-液两相包裹体,另有少量的气相包裹体,未见富CO2和含子矿物的流体包裹体,显示出张性构造环境流

  3. Vertically aligned multiwalled carbon nanotubes as electronic interconnects.

    OpenAIRE

    Gopee, Vimal C.

    2017-01-01

    The drive for miniaturisation of electronic circuits provides new materials challenges for the electronics industry. Indeed, the continued downscaling of transistor dimensions, described by Moore’s Law, has led to a race to find suitable replacements for current interconnect materials to replace copper. Carbon nanotubes have been studied as a suitable replacement for copper due to its superior electrical, thermal and mechanical properties. One of the advantages of using carbon nanotubes is th...

  4. Electrochemical performance of coal-based activated carbon electrodes modified by copper nitrate for supercapacitor%硝酸铜改性超级电容器用煤基活性炭电极材料的电化学性能

    Institute of Scientific and Technical Information of China (English)

    马亚芬; 谌伦建; 邢宝林; 徐冰; 黄光许; 张传祥

    2012-01-01

    Coal-based activated carbon(AC) was prepared from Indonesia lignite by KOH as activator. In order to improve electrochemical properties of AC, the AC was modified by means of soaking in copper nitrate solution and subsequent pyrolysis. The specific surface area and pore distribution of activated carbons before and after modification were studied by nitrogen adsorption at 77 K, the crystallite structure and surface morphology of activated carbons were characterized by SEM and XRD. Moreover, the wettability and electrochemical performance of activated carbon electrodes were researched by contact angle and constant current charge-discharge, cyclic voltammograms, alternating current impedance, respectively. The results indicate that the portion pores of modified AC , especially the micropores, are blocked by the oxides produced from the Cu ( NO3 ) 2 decomposition, the specific surface and total pore volume decrease, the rate of mesopores increases. Meanwhile, the oxides loaded on AC by copper nitrate modification not only improves the wettability of AC to electrolyte, but also produces an obvious pseudo-capacitance effect, the specific capacitance of modified AC can be enhanced. Based on this study, the optimum concentration of Cu( NO3 )2 solution was 2% ,the specific capacitance of modified AC electrode can be reached up to 322 F/g, and the electrochemical performance can be improved.%以印尼褐煤为原料、KOH活化法制备的煤基活性炭,采用硝酸铜溶液浸渍-高温热解法对其进行改性处理,低温N2吸附法对改性前后活性炭的孔结构进行表征,SEM和XRD对改性前后活性炭的表面形态和微晶结构进行表征,并测定KOH对活性炭的润湿性及活性炭电极的恒流充放电、循环伏安、交流阻抗等电化学性能.结果表明:硝酸铜改性可能使部分孔隙(尤其是微孔堵塞)的比表面积和孔容积降低,但中孔率有所提高;硝酸铜改性可以提高KOH溶液对活性炭的润湿性,在

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-15

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

  6. The Revovery of Copper and Cobalt from Oxidized Copper Ore and Converter Slag

    OpenAIRE

    ZİYADANOĞULLARI, Berrin; ZİYADANOĞULLARI, Recep

    1999-01-01

    The aim of this study was to develop a method for obtaining copper and cobalt from oxidized copper ore and converter slag. In order to convert the copper and cobalt into sulfate compounds the main step was to roast the samples obtained by sulfurization and transfer the samples into solution. First the oxidized copper ore was roasted, followed by the mixture of converter slag and oxidized copper ore. Since the levels of copper and cobalt were low, the sulfurization process was carri...

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

    DEFF Research Database (Denmark)

    Lüthje, Freja L.; Hasman, Henrik; Aarestrup, Frank Møller;

    2014-01-01

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

  8. Cover crops influence soil microorganisms and phytoextraction of copper from a moderately contaminated vineyard.

    Science.gov (United States)

    Mackie, K A; Schmidt, H P; Müller, T; Kandeler, E

    2014-12-01

    We investigated the ability of summer (Avena sativa [oat], Trifolium incarnatum [crimson clover], Chenopodium [goosefoot]) and winter (Vicia villosa [hairy vetch], Secale Cereale L. [Rye], Brassica napus L. partim [rape]) cover crops, including a mixed species treatment, to extract copper from an organic vineyard soil in situ and the microbial communities that may support it. Clover had the highest copper content (14.3mgCukg(-1) DM). However, it was the amount of total biomass production that determined which species was most effective at overall copper removal per hectare. The winter crop rye produced significantly higher amounts of biomass (3532kgDMha(-1)) and, therefore, removed significantly higher amounts of copper (14,920mgCuha(-1)), despite less accumulation of copper in plant shoots. The maximum annual removal rate, a summation of best performing summer and winter crops, would be 0.033kgCuha(-1)y(-1). Due to this low annual extraction efficiency, which is less than the 6kgCuha(-1)y(-1) permitted for application, phytoextraction cannot be recommended as a general method of copper extraction from vineyards. Copper concentration did not influence aboveground or belowground properties, as indicated by sampling at two distances from the grapevine row with different soil copper concentrations. Soil microorganisms may have become tolerant to the copper levels at this site. Microbial biomass and soil enzyme activities (arylsulfatase and phosphatase) were instead driven by seasonal fluxes of resource pools. Gram+ bacteria were associated with high soil moisture, while fungi seemed to be driven by extractable carbon, which was linked to high plant biomass. There was no microbial group associated with the increased phytoextraction of copper. Moreover, treatment did not influence the abundance, activity or community structure of soil microorganisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Majorana Electroformed Copper Mechanical Analysis

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-30

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

  10. Hereditary iron and copper deposition

    DEFF Research Database (Denmark)

    Aaseth, Jan; Flaten, Trond Peder; Andersen, Ole

    2007-01-01

    can be successfully treated, emphasizing the importance of early diagnosis. Serum ferritin values, transferrin saturation and genetic analysis are used when diagnosing haemochromatosis. The diagnostics of Wilson's disease depends on the use of urinary copper values, serum ceruloplasmin and liver...

  11. Condition of copper and organic matter in the soil contaminated with metal remediation of humic substances.

    Science.gov (United States)

    Kolchanova, Kseniia; Barsova, Natalia; Motuzova, Galina; Stepanov, Andrey; Karpukhin, Mikhail

    2017-04-01

    The aim of this study was to investigate the forms of copper and transformation of organic matter in the soil under the influence of humic substances (potassium humate, which was obtained from coal). The object of research was the top layer of soil model field experience. Field experiments were carried out in 10-liter plastic containers.The upper layers were constructed artificially as mixture of loam, sand and peat. Below it was a layer of loam, then gravel and under it we installed lysimeters. The experiment was conducted in 3 settings: 1) control, 2) control + Cu, and 3) control + Cu + potassium humate . Copper was deposited into upper layer at soil column construction as dry powder (CuSO4*5H2O), which is 1000mg per kg. Humic substance was introduced on surface as liquid form. The focus was the state of the copper and organic matter of solid and liquid phase. In the solid phase pH, carbon content, the molecular-mass distributions for the organic matter, total (HNO3 conc.+ H2O2; decomposition in a microwave oven) and acid-soluble (1H HNO3) copper content, sequential extraction of copper (1 M MgCl2, acetate buffer pH 4,8 (AAB), 1% EDTA) were determined. For liquid phase characteristics aqueous extract was obtained and identified therein: pH, total activity and copper content and water-soluble organic matter(WOM) amphiphilic properties. The introduction of copper is accompanied by a decrease in pH in soils from 7 to 6,3. The introduction of the humic substance softens this effect. Introducing humic preparation gives an increase in carbon at 0.5%. HS and copper has no significant effect on the molecular-mass distribution of solid organic matter. Only about 4% introduced copper accounted for the exchangeable form (MgCl2) for the variant only copper contaminated. Copper, mainly precipitated as hydroxides, moved in an AAB extract. And compared with the exchangeable forms its quantity increases by 10 times. Still more copper goes into an extract of EDTA, about half of

  12. Use of copper radioisotopes in investigating disorders of copper metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Camakaris, J.; Voskoboinik, I.; Brooks, H.; Greenough, M. [University of Melbourne, Parkville, VIC (Australia). Department of Genetics; Smith, S. [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). Radiopharmaceuticals Division; Mercer, J. [Deakin University, Rusden Campus, Clayton, VIC (Australia). Centre of Cellular and Molecular Biology

    1998-12-31

    Full text: Copper is an essential trace element for life as a number of vital enzymes require it. Copper deficiency can lead to neurological disorders, osteoporosis and weakening of arteries. However Cu is also highly toxic and homeostatic mechanisms have evolved to maintain Cu at levels which satisfy requirements but do not cause toxicity. Toxicity is mediated by the oxidative capacity of Cu and its ability to generate toxic free radicals. There are several acquired and inherited diseases due to either Cu toxicity or Cu deficiency. The study of these diseases facilitates identification of genes and proteins involved in copper homeostasis, and this in turn will provide rational therapeutic approaches. Our studies have focused on Menkes disease in humans which is an inherited and usually lethal copper deficiency. Using copper radioisotopes {sup 64}Cu (t 1/2 = 12.8 hr) and {sup 67}Cu (t 1/2 = 61 hr) we have studied the protein which is mutated in Menkes disease. This is a transmembrane copper pump which is responsible for absorption of copper into the body and also functions to pump out excess Cu from cells when Cu is elevated. It is therefore a vital component of normal Cu homeostasis. We have provided the first biochemical evidence that the Menkes protein functions as a P-type ATPase Cu pump (Voskoboinik et al., FEBS Letters, in press) and these data will be discussed. The assay involved pumping of radiocopper into purified membrane vesicles. Furthermore we have transfected normal and mutant Menkes genes into cells and are carrying out structure-function studies. We are also studying the role of amyloid precursor protein (APP) as a Cu transport protein in order to determine how Cu regulates this protein and its cleavage products. These studies will provide vital information on the relationship between Cu and APP and processes which lead to Alzheimers disease

  13. Fabrication of copper nanorods by low-temperature metal organic chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; Frank Leung-Yuk Lam; HU Xijun; YAN Zifeng

    2006-01-01

    Copper nanorods have been synthesized in mesoporous SBA-15 by a low-temperature metal organic chemical vapor deposition (MOCVD)employing copper (Ⅱ) acetylacetonate, Cu(acac)2,and hydrogen as a precursor and reactant gas, respectively. The hydrogen plays an important role in chemical reduction of oganometallic precursor which enhances mass transfer in the interior of the SBA-15 porous substrate. Such copper nanostructures are of great potentials in the semiconductor due to their unusual optical, magnetic and electronic properties.In addition, it has been found that chemically modifying the substrate surface by carbon deposition is crucial to such synthesis of copper nanostructures in the interior of the SBA-15, which is able to change the surface properties of SBA-15 from hydrophilic to hydrophobic to promote the adsorption of organic cupric precursor. It has also been found that the copper nanoparticles deposited on the external surface are almost eliminated and the copper nanorods are more distinct while the product was treated with ammonia. This approach could be achieved under a mild condition: a low temperature (400℃) and vacuum (2 kPa) which is extremely milder than the conventional method. It actually sounds as a foundation which is the first time to synthesize a copper nanorod at a mild condition of a low reaction temperature and pressure.

  14. Water Quality Criteria for Copper Based on the BLM Approach in the Freshwater in China

    Science.gov (United States)

    Zhang, Yahui; Zang, Wenchao; Qin, Lumei; Zheng, Lei; Cao, Ying; Yan, Zhenguang; Yi, Xianliang; Zeng, Honghu; Liu, Zhengtao

    2017-01-01

    The bioavailability and toxicity of metals to aquatic organisms are highly dependent on water quality parameters in freshwaters. The biotic ligand model (BLM) for copper is an approach to generate the water quality criteria (WQC) with water chemistry in the ambient environment. However, few studies were carried out on the WQCs for copper based on the BLM approach in China. In the present study, the toxicity for copper to native Chinese aquatic organisms was conducted and the published toxicity data with water quality parameters to Chinese aquatic species were collected to derive the WQCs for copper by the BLM approach. The BLM-based WQCs (the criterion maximum criteria (CMC) and the criterion continuous concentration (CCC)) for copper in the freshwater for the nation and in the Taihu Lake were obtained. The CMC and CCC values for copper in China were derived to be 1.391 μg/L and 0.495 μg/L, respectively, and the CMC and CCC in the Taihu Lake were 32.194 μg/L and 9.697 μg/L. The high concentration of dissolved organic carbon might be a main reason which resulted in the higher WQC values in the Taihu Lake. The WQC of copper in the freshwater would provide a scientific foundation for water quality standards and the environment risk assessment in China. PMID:28166229

  15. Sedimentation of Copper Droplets after their Coagulation and Growth. Laboratory Scale

    Directory of Open Access Journals (Sweden)

    Wołczyński W.

    2016-03-01

    Full Text Available The suspension of copper droplets in the slag is considered. The copper/slug suspension is delivered as the product from the direct-to-blister process which is applied in the KGHM – Polska Miedź (Polish Copper S.A. factory. The droplets / slag suspension was treated by a special set of reagents (patented by the authors to improve the coagulation process. On the other hand, the observations are made to estimate if the melting / reduction process in the furnace is sufficiently effective to avoid a remaining of carbon in the copper droplets. The coagulation process was carried out in the crucible (laboratory scale. However, conditions imposed to the coagulation / solidification process in the laboratory scale were to some extent similar to those applied usually in the industry when the suspension is subjected to the analogous treatment in the electric arc-furnace. Some suggestions are formulated how to improve the industrial direct-to-blister process.

  16. Copper chloride electrolyzer for the production of hydrogen via the copper-chlorine thermochemical cycle

    Science.gov (United States)

    Roy, Rahul Dev

    Hydrogen is considered a key element in solving the upcoming energy crisis, it is not the primary fuel source but an "energy carrier" similar to electricity and has to be produced using some other hydrogen rich source. Thermochemical water decomposition is a promising alternative to steam-methane reforming and electrolytic water splitting for a sustainable method of large-scale hydrogen production. The Copper-Chlorine thermochemical cycle is one of prime contenders among all the other thermochemical cycles being studied because of its low energy requirements compared to others and mild operating conditions, therefore making it available to be readily integrated to the available nuclear reactors or solar energy installations. This present work focuses on the study and development of a proton exchange membrane (PEM) electrolyzer cell for the Copper-Chlorine thermo chemical cycle to obtain a better understanding through experiments and models of this process. Different operating and design parameters such as temperature, flow rate, current density, membranes and gas diffusion layers were considered to reduce the voltage and hence increase the efficiency of the electrolyzer. The effects of catalyst and mass transfer were studied on the thin film electrode using a rotating disk electrode (RDE) setup. A mathematical model was also developed to monitor the performance of the electrolyzer by predicting the change in concentration of copper chloride in the system with respect to time. It is observed that flow rate and temperature plays a major role in decreasing the voltage drop. There was no effect of catalyst in the anode when compared to a bare anode at lower flow rates; but at higher flow rates there was significant decrease in voltage drop when a carbon cloth was placed at the anode end. High surface area carbon black has comparable activity towards CuCl oxidation with conventional catalyst like Platinum or Ruthenium oxide. It is also seen that mass transfers possess a

  17. Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

    Directory of Open Access Journals (Sweden)

    Zhengqi Guo

    2016-04-01

    Full Text Available In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of copper and iron.

  18. Tuning of structural, light emission and wetting properties of nanostructured copper oxide-porous silicon matrix formed on electrochemically etched copper-coated silicon substrates

    Science.gov (United States)

    Naddaf, M.

    2017-01-01

    Matrices of copper oxide-porous silicon nanostructures have been formed by electrochemical etching of copper-coated silicon surfaces in HF-based solution at different etching times (5-15 min). Micro-Raman, X-ray diffraction and X-ray photoelectron spectroscopy results show that the nature of copper oxide in the matrix changes from single-phase copper (I) oxide (Cu2O) to single-phase copper (II) oxide (CuO) on increasing the etching time. This is accompanied with important variation in the content of carbon, carbon hydrides, carbonyl compounds and silicon oxide in the matrix. The matrix formed at the low etching time (5 min) exhibits a single broad "blue" room-temperature photoluminescence (PL) band. On increasing the etching time, the intensity of this band decreases and a much stronger "red" PL band emerges in the PL spectra. The relative intensity of this band with respect to the "blue" band significantly increases on increasing the etching time. The "blue" and "red" PL bands are attributed to Cu2O and porous silicon of the matrix, respectively. In addition, the water contact angle measurements reveal that the hydrophobicity of the matrix surface can be tuned from hydrophobic to superhydrophobic state by controlling the etching time.

  19. Renal cortex copper concentration in acute copper poisoning in calves

    Directory of Open Access Journals (Sweden)

    Luis E. Fazzio

    2012-01-01

    Full Text Available The aim of this study was to estimate the diagnostic value of renal cortex copper (Cu concentration in clinical cases of acute copper poisoning (ACP. A total of 97 calves that died due to subcutaneous copper administration were compiled in eleven farms. At least, one necropsy was conducted on each farm and samples for complementary analysis were taken. The degree of autolysis in each necropsy was evaluated. The cases appeared on extensive grazing calf breeding and intensive feedlot farms, in calves of 60 to 200 kg body weight. Mortality varied from 0.86 to 6.96 %, on the farms studied. The first succumbed calf was found on the farms between 6 and 72 hours after the susbcutaneous Cu administration. As discrepancies regarding the reference value arose, the local value (19.9 parts per million was used, confirming the diagnosis of acute copper poisoning in 93% of the analyzed kidney samples. These results confirm the value of analysis of the cortical kidney Cu concentration for the diagnosis of acute copper poisoning.

  20. Copper metallurgy at the crossroads

    Directory of Open Access Journals (Sweden)

    Habashi F.

    2007-01-01

    Full Text Available Copper technology changed from the vertical to the horizontal furnace and from the roast reaction to converting towards the end of the last century. However, the horizontal furnace proved to be an inefficient and polluting reactor. As a result many attempts were made to replace it. In the past 50 years new successful melting processes were introduced on an industrial scale that were more energy efficient and less polluting. In addition, smelting and converting were conducted in a single reactor in which the concentrate was fed and the raw copper was produced. The standing problem in many countries, however, is marketing 3 tonnes of sulfuric acid per tonne of copper produced as well as emitting large amounts of excess SO2 in the atmosphere. Pressure hydrometallurgy offers the possibility of liberating the copper industry from SO2 problem. Heap leaching technology has become a gigantic operation. Combined with solvent extraction and electrowinning it contributes today to about 20% of copper production and is expected to grow. Pressure leaching offers the possibility of liberating the copper industry from SO2 problem. The technology is over hundred years old. It is applied for leaching a variety of ores and concentrates. Hydrothermal oxidation of sulfide concentrates has the enormous advantage of producing elemental sulfur, hence solving the SO2 and sulfuric acid problems found in smelters. Precipitation of metals such as nickel and cobalt under hydrothermal conditions has been used for over 50 years. It has the advantage of a compact plant but the disadvantage of producing ammonium sulfate as a co-product. In case of copper, however, precipitation takes place without the need of neutralizing the acid, which is a great advantage and could be an excellent substitute for electrowinning which is energy intensive and occupies extensive space. Recent advances in the engineering aspects of pressure equipment design open the door widely for increased

  1. Effects of short immersion time and cooling rates of copperizing process to the evolution of microstructures and copper behavior in the dead mild steel

    Science.gov (United States)

    Jatimurti, Wikan; Sutarsis, Cunika, Aprida Ulya

    2017-01-01

    In a dead mild steel with maximum carbon content of 0.15%, carbon does not contribute much to its strength. By adding copper as an alloying element, a balance between strength and ductility could be obtained through grain refining, solid solution, or Cu precipitation. This research aimed to analyse the changes in microstructures and copper behaviour on AISI 1006, including the phases formed, composition, and Cu dispersion. The addition of cooper was done by immersing steel into molten copper or so we called, copperizing using the principles of diffusion. Specimens were cut with 6 × 3 × 0.3 cm measurement then preheated to 900°C and melting the copper at 1100°C. Subsequently, the immersion of the specimens into molten copper varied to 5 and 7 minutes, and also varying the cooling rate to annealing, normalizing, and quenching. A series of test being conduct were optical microscope test, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), optical emission spectroscopy (OES), and X-ray diffraction (XRD). The results showed that the longer the immersion time and slower cooling rate, the more Cu diffused causing smaller grain size with the highest Cu diffused recorded was 0.277% in the copperized AISI 1006 steel with 7 minutes of immersion and was annealed. The grain size reduced to 23041.5404 µm2. The annealed specimens show ferrite phase, the normalized ones show polygonal ferrite phase, while the quenched ones show granular bainite phase. The phase formed is single phase Cu. In addition, the normalized and quenched specimens show that Cu dissolved in Fe crystal forming solid solution.

  2. Uptake of copper ion by activated sludge and its bacterial community variation analyzed by 16S rDNA

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The effect and uptake of copper ion on SBR(sequence batch reactor) biological treatment system was studied in this paper. Special nutrient and powder activated carbon(PAC) additive were tested as uptake stimulation technique. Results showed that copper ion had higher effect on unacclimated activated sludge system than on acclimated one. The special nutrient adding could enhance the uptake of copper significantly, while PAC adding could improve the sludge settling and decrease the turbidity of effluent. The variation of bacterial community analyzed by 16S rDNA method showed the acclimation of copper could increase copper resistance species, and excess accumulation could cause some species diminish. It was confirmed that acclimation could improve the resistance and uptake ability of microorganism to heavy metal.

  3. Erosion of Copper Target Irradiated by Ion Beam

    CERN Document Server

    Polosatkin, S V; Grishnyaev, E S; Konstantinov, S G; Shoshin, A A

    2012-01-01

    Erosion of copper target irradiated by deuterium ion beam with ultimate fluence is studied. The target originally destined for neutron generation represents bulk copper substrate covered by 3-\\mum titanium layer. The target was irradiated by deuterium ion beam generated in Bayard-Alpert type ion source with energy of ions 17.5 keV/nuclear. Maximal fluence in the center of the target achieves 2.5x10^23atoms/cm^2. Measurements of the profile of irradiated target and estimation of fluence shows that physical sputtering is a dominating process that determines the target erosion Most interesting feature is growth of \\mum-size tadpole-shaped structures, localized in the cracks of the surface. RFA analysis of these structures showed extremely large (up to 60%at.) carbon content.

  4. Effect the conditions of the acid-thermal modification of clinoptilolite have on the catalytic properties of palladium-copper complexes anchored on it in the reaction of carbon monoxide oxidation

    Science.gov (United States)

    Rakitskaya, T. L.; Kiose, T. A.; Ennan, A. A.; Golubchik, K. O.; Oleksenko, L. P.; Gerasiova, V. G.

    2016-06-01

    The dependence of the physicochemical and structural-adsorption properties of natural and acid-thermal modified clinoptilolite, and of Pd(II)-Cu(II) catalysts based on them, on the duration of acid-thermal modification is investigated. The samples under study are described via XRD and thermal gravimetric (DTG and DTA) analysis, IR, DR UV-Vis, EPR spectroscopy, and water vapor adsorption. Values of both the specific surface area ( S sp) and pH of aqueous suspensions are determined. The resulting catalysts are tested in the reaction of low-temperature carbon monoxide oxidation with air oxygen. A conclusion is drawn about the nature of surface bimetallic Pd(II)-Cu(II) complexes. The greatest catalytic activity is shown by complexes based on clinoptilolite and modified with 3 M HNO3 for 0.5 and 1 h.

  5. Metal-mediated controllable creation of secondary, tertiary, and quaternary carbon centers: a powerful strategy for the synthesis of iron, cobalt, and copper complexes with in situ generated substituted 1-pyridineimidazo[1,5-a]pyridine ligands.

    Science.gov (United States)

    Chen, Yanmei; Li, Lei; Chen, Zhou; Liu, Yonglu; Hu, Hailiang; Chen, Wenqian; Liu, Wei; Li, Yahong; Lei, Tao; Cao, Yanyuan; Kang, Zhenghui; Lin, Miaoshui; Li, Wu

    2012-09-17

    An efficient strategy for the synthesis of a wide variety of coordination complexes has been developed. The synthetic protocol involves a solvothermal in situ metal-ligand reaction of picolinaldehyde, ammonium acetate, and transition-metal ions, leading to the generation of 12 coordination complexes supported by a novel class of substituted 1-pyridineimidazo[1,5-a]pyridine ligands (L1-L5). The ligands L1-L5 were afforded by metal-mediated controllable conversion of the aldehyde group of picolialdehyde into a ketone and secondary, tertiary, and quaternary carbon centers, respectively. Complexes of various nuclearities were obtained: from mono-, di-, and tetranuclear to 1D chain polymers. The structures of the in situ formed complexes could be controlled rationally via the choice of appropriate starting materials and tuning of the ratio of the starting materials. The plausible mechanisms for the formation of the ligands L1-L5 were proposed.

  6. Remoção de íons de cobre de aguardente utilizando carvão ativo e resinas de troca iônica = Copper ions remotion from sugarcane spirit by activated carbon and ion exchange resins

    Directory of Open Access Journals (Sweden)

    Leo Kunigk

    2011-01-01

    Full Text Available A aguardente é a bebida fermento-destilada mais importante no Brasil. Caso a concentração de cobre (Cu2+, presente na aguardente, fosse inferior a 2,0 mg L-1, ela poderia ser exportada para diversos países europeus apesar da Legislação Brasileira permitir um teor de cobre em aguardente igual ou inferir a 5,0 mg L-1. Este trabalho mostrou que aaguardente contaminada com esses íons em concentrações de 4,0; 7,0 e 9,0 mg L-1 pode ser recuperada utilizando tanto carvão ativo como resinas de troca iônica, podendo reutilizar estes materiais adsorventes. Quando a concentração de Cu2+ é igual a 9,0 mg L-1, o carvão ativado pode ser reutilizado até três vezes e as resinas de troca iônica podem ser reutilizadas até sete vezes.Sugarcane spirit (aguardente is the most important fermented/distilled beverage in Brazil. If the concentration of cooper (Cu2+ in sugarcane spirits was less than 2.0 mg L-1, it could be exported to several European countries. This study showed that the sugarcane spirits contaminated with these ions with a concentrationof 4.0, 7.0 and 9.0 mg L-1 can be recovered using both active carbon and ion-exchange resins, reusing these absorbent materials. When the concentration of Cu2+ is equal to 9.0 mg L-1, active carbon can be reused up to 3 times and ion-exchange resins up to 7 times.

  7. Differential effects of copper on three species of scleractinian corals and their algal symbionts (Symbiodinium spp.).

    Science.gov (United States)

    Bielmyer, G K; Grosell, M; Bhagooli, R; Baker, A C; Langdon, C; Gillette, P; Capo, T R

    2010-04-15

    Land-based sources of pollution have been identified as significant stressors linked to the widespread declines of coral cover in coastal reef ecosystems over the last 30 years. Metal contaminants, although noted as a concern, have not been closely monitored in these sensitive ecosystems, nor have their potential impacts on coral-algal symbioses been characterized. In this study, three species of laboratory-reared scleractinian corals, Acropora cervicornis, Pocillopora damicornis, and Montastraea faveolata each containing different algal symbionts (Symbiodinium A3, C1 and D1a, respectively) were exposed to copper (ranging from 2 to 20microg/L) for 5 weeks. At the end of the exposure period, copper had accumulated in the endosymbiotic dinoflagellate ("zooxanthellae") and animal tissue of A. cervicornis and the animal tissue of M. faveolata; however, no copper accumulation was detected in the zooxanthellae or animal tissue of P. damicornis. The three coral species exhibited significantly different sensitivities to copper, with effects occurring in A. cervicornis and P. damicornis at copper concentrations as low as 4microg/L. Copper exposure affected zooxanthellae photosynthesis in A. cervicornis and P. damicornis, and carbonic anhydrase was significantly decreased in A. cervicornis and M. faveolata. Likewise, significant decreases in skeletal growth were observed in A. cervicornis and P. damicornis after copper exposure. Based on preliminary results, no changes in Symbiodinium communities were apparent in response to increasing copper concentration. These results indicate that the relationships between physiological/toxicological endpoints and copper accumulation between coral species differ, suggesting different mechanisms of toxicity and/or susceptibility. This may be driven, in part, by differences in the algal symbiont communities of the coral species in question.

  8. Modification of soil microbial activity and several hydrolases in a forest soil artificially contaminated with copper

    Science.gov (United States)

    Bellas, Rosa; Leirós, Mā Carmen; Gil-Sotres, Fernando; Trasar-Cepeda, Carmen

    2010-05-01

    Soils have long been exposed to the adverse effects of human activities, which negatively affect soil biological activity. As a result of their functions and ubiquitous presence microorganisms can serve as environmental indicators of soil pollution. Some features of soil microorganisms, such as the microbial biomass size, respiration rate, and enzyme activity are often used as bioindicators of the ecotoxicity of heavy metals. Although copper is essential for microorganisms, excessive concentrations have a negative influence on processes mediated by microorganisms. In this study we measured the response of some microbial indicators to Cu pollution in a forest soil, with the aim of evaluating their potential for predicting Cu contamination. Samples of an Ah horizon from a forest soil under oakwood vegetation (Quercus robur L.) were contaminated in the laboratory with copper added at different doses (0, 120, 360, 1080 and 3240 mg kg-1) as CuCl2×2H2O. The soil samples were kept for 7 days at 25 °C and at a moisture content corresponding to the water holding capacity, and thereafter were analysed for carbon and nitrogen mineralization capacity, microbial biomass C, seed germination and root elongation tests, and for urease, phosphomonoesterase, catalase and ß-glucosidase activities. In addition, carbon mineralization kinetics were studied, by plotting the log of residual C against incubation time, and the metabolic coefficient, qCO2, was estimated. Both organic carbon and nitrogen mineralization were lower in polluted samples, with the greatest decrease observed in the sample contaminated with 1080 mg kg-1. In all samples carbon mineralization followed first order kinetics; the C mineralization constant was lower in contaminated than in uncontaminated samples and, in general, decreased with increasing doses of copper. Moreover, it appears that copper contamination not only reduced the N mineralization capacity, but also modified the N mineralization process, since in

  9. 21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

    Science.gov (United States)

    2010-04-01

    ... (chlorophyllin-copper complex). 73.1125 Section 73.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT....1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). (a) Identity. (1) The color additive potassium sodium copper chlorophyllin is a green to black powder obtained from chlorophyll...

  10. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). (a) Identity...

  11. Testing Corrosion Inhibitors for the Conservation of Archaeological Copper and Copper Alloys

    Directory of Open Access Journals (Sweden)

    Robert B. Faltermeier

    1997-11-01

    Full Text Available This is a synopsis of the Ph.D. research undertaken at the Institute of Archaeology, University College London. The aim was to evaluate corrosion inhibitors for use in the conservation of copper and copper alloy archaeological artefacts. The objective of this work was to acquire an insight into the performance of copper corrosion inhibitors, when applied to archaeological copper.

  12. NMR spectroscopic investigations on copper-catalyzed reactions and zintl anions

    OpenAIRE

    Koch, Carina

    2016-01-01

    The copper-catalyzed asymmetric conjugated 1,4-addition reaction of organozinc reagents to a,b-unsaturated compounds is a very effective and widely used method for the enantioselective carbon-carbon bond formation. By the use of phosphoramidite ligands it is possible to reach ee-values and conversion up to > 99 %. Furthermore, this outstanding reaction provides lower costs in comparison to other transition-metal catalyzed reactions and compatibility to many functional groups. Despite the grea...

  13. The link between copper and Wilson's disease.

    Science.gov (United States)

    Purchase, Rupert

    2013-01-01

    Wilson's disease (hepatolenticular degeneration) is a rare inherited autosomal recessive disorder of copper metabolism leading to copper accumulation in the liver and extrahepatic organs such as the brain and cornea. Patients may present with combinations of hepatic, neurological and psychiatric symptoms. Copper is the therapeutic target for the treatment of Wilson's disease. But how did copper come to be linked with Wilson's disease? The answer encompasses a study of enzootic neonatal ataxia in lambs in the 1930s, the copper-chelating properties of British Anti-Lewisite, and the chemical analysis for copper of the organs of deceased Wilson's disease patients in the mid-to-late 1940s. Wilson's disease is one of a number of copper-related disorders where loss of copper homeostasis as a result of genetic, nutritional or environmental factors affects human health.

  14. Determination of copper in clarified apple juices.

    Science.gov (United States)

    Zeiner, Michaela; Juranović Cindrić, Iva; Kröppl, Michaela; Stingeder, Gerhard

    2010-03-24

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

  15. Synthesis of aminoarenethiolato-copper(I) complexes

    NARCIS (Netherlands)

    Sperotto, E.; van Klink, G.P.M.; van Koten, G.

    2008-01-01

    Copper(I)-mediated reactions have recently become the choice for large industrial scale applications, since copper is environmentally friendly and cheaper than other transition metals already explored. However, most organocopper compounds still present several limitations including the sensitivity t

  16. Global assessment of undiscovered copper resources

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Deposits, prospects, and permissive tracts for porphyry and sediment-hosted copper resources worldwide, with estimates of undiscovered copper resources. pCu_tracts...

  17. EFFECT OF COPPER ON PASSIVITY AND CORROSION ...

    African Journals Online (AJOL)

    2014-06-30

    Jun 30, 2014 ... metallic copper enriched on the surface film of austenitic stainless ... Dispersed inclusions of this phase can influence the stability of .... two microstructures showed that copper concentration possessed a non-uniform chemical.

  18. Copper tolerance and virulence in bacteria

    Science.gov (United States)

    Ladomersky, Erik; Petris, Michael J.

    2015-01-01

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

  19. In situ Immobilization of Copper Nanoparticles on Polydopamine Coated Graphene Oxide for H2O2 Determination

    OpenAIRE

    Yingzhu Liu; Yanwei Han; Rongsheng Chen; Haijun Zhang; Simin Liu; Feng Liang

    2016-01-01

    Nanostructured electrochemical sensors often suffer from irreversible aggregation and poor adhesion to the supporting materials, resulting in reduced sensitivity and selectivity over time. We describe a versatile method for fabrication of a H2O2 sensor by immobilizing copper nanoparticles (Cu NPs; 20 nm) on graphene oxide (GO) sheets via in-situ reduction of copper(II) on a polydopamine (PDA) coating on a glassy carbon electrode. The PDA film with its amino groups and catechol groups acts as ...

  20. Laser forming of structures of zinc oxide on a surface of products from copper alloys

    Science.gov (United States)

    Abramov, D. V.; Gorudko, T. N.; Koblov, A. N.; Nogtev, D. S.; Novikova, O. A.

    Laser formation of a protective zinc oxide layer on a surface of products from copper alloys is present. This layer is formed with using of carbon nanotubes. Destructions of the basic material are avoided or minimized at laser nanostructuring of product surfaces. Such laser processing can be made repeatedly. Offered covering have self-clearing and water-repellent properties.

  1. Preparation of Pure Copper Powder from Acidic Copper Chloride Waste Etchant

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The method for the recycling of copper from copper chloride solution was developed. This process consists of extraction of copper, purification and particle size reduction. In the first step, reductive metal scraps were added to acidic copper chloride waste enchants produced in the PCB industry to obtain copper powder.Composition analysis showed that this powder contained impurities such as Fe, Ni, and water. So, drying and purification were carried out by using microwave and a centrifugal separator. Thereby the copper powder had a purity of higher than 99% and spherical form in morphology. The copper powder size was decreased by ball milling.

  2. Coating of a steel wire with copper

    Science.gov (United States)

    Vdovin, K. N.; Dubskii, G. A.; Nefed'ev, A. A.; Derevyanko, D. V.

    2016-03-01

    The process of coating of a steel wire with liquid copper at a high speed (>1 m/s) is considered. The results of long-term studies of copperizing under laboratory conditions and electron-microscopic investigation of the copper-steel adhesion are used to develop a mathematical model for coating of a steel wire with copper and to create a commercial setup to implement this process.

  3. Canine Models for Copper Homeostasis Disorders

    OpenAIRE

    Xiaoyan Wu; Leegwater, Peter A. J.; Hille Fieten

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper me...

  4. 49 CFR 192.279 - Copper pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Copper pipe. 192.279 Section 192.279... Copper pipe. Copper pipe may not be threaded except that copper pipe used for joining screw fittings or... heavier wall pipe listed in Table C1 of ASME/ANSI B16.5. [Amdt. 192-62, 54 FR 5628, Feb. 6, 1989, as...

  5. Modulation of tau phosphorylation by environmental copper

    OpenAIRE

    Voss, Kellen; Harris, Christopher; Ralle, Martina; Duffy, Megan; Murchison, Charles; Joseph F. Quinn

    2014-01-01

    Background The transition metal copper enhances amyloid β aggregation and neurotoxicity, and in models of concomitant amyloid and tau pathology, copper also promotes tau aggregation. Since it is not clear if the effects of environmental copper upon tau pathology are dependent on the presence of pathological amyloid β, we tested the effects of copper overload and complexing in disease models which lack pathological amyloid β. Methods We used cell culture and transgenic murine models to test th...

  6. Canine Models for Copper Homeostasis Disorders

    OpenAIRE

    Xiaoyan Wu; Leegwater, Peter A.J.; Hille Fieten

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper me...

  7. Tensile behavior of nanocrystalline copper

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, P.G.; Weertman, J.R. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Eastman, J.A. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering]|[Argonne National Lab., IL (United States). Materials Science Div.

    1995-11-01

    High density nanocrystalline copper produced by inert gas condensation was tested in tension. Displacements were measured using foil strain gauges, which greatly improved the accuracy of the strain data. The Young`s modulus of nanocrystalline copper was found to be consistent with that of coarse-grained copper. Total elongations of {approx} 1% were observed in samples with grain sizes less than 50 nm, while a sample with a grain size of 110 nm exhibited more than 10% elongation, perhaps signifying a change to a dislocation-based deformation mechanism in the larger-grained material. In addition, tensile tests were performed as a function of strain rate, with a possible trend of decreased strength and increased elongation as the strain rate was decreased.

  8. Monitoring copper in Wilson's disease.

    Science.gov (United States)

    Walshe, J M

    2010-01-01

    Monitoring copper metabolism in patients with Wilson's disease is not an exact science. At present, there are no simple methods of estimating the total body load of this metal. Indirect methods must therefore be used. A survey of the current literature shows that most approaches rely on the determination of blood and urine copper concentration. Both these should decrease with treatment. In parallel with decreased copper concentration, there should be subsequent improvement in more routine laboratory tests including liver and renal function, blood count parameters, and clotting factors. Lack of compliance is revealed by a reversal of this trend. This chapter critically reviews current testing methods and describes other approaches that may be helpful.

  9. Mechanochemical reduction of copper sulfide

    DEFF Research Database (Denmark)

    Balaz, P.; Takacs, L.; Jiang, Jianzhong

    2002-01-01

    The mechanochemical reduction of copper sulfide with iron was induced in a Fritsch P-6 planetary mill, using WC vial filled with argon and WC balls. Samples milled for specific intervals were analyzed by XRD and Mossbauer spectroscopy. Most of the reaction takes place during the first 10 min...... of milling and only FeS and Cu are found after 60 min. The main chemical process is accompanied by phase transformations of the sulfide phases as a result of milling. Djurleite partially transformed to chalcocite and a tetragonal copper sulfide phase before reduction. The cubic modification of FeS was formed...... first, transforming to hexagonal during the later stages of the process. The formation of off-stoichiometric phases and the release of some elemental sulfur by copper sulfide are also probable....

  10. Copper tolerance of Trichoderma species

    Directory of Open Access Journals (Sweden)

    Jovičić-Petrović Jelena

    2014-01-01

    Full Text Available Some Trichoderma strains can persist in ecosystems with high concentrations of heavy metals. The aim of this research was to examine the variability of Trichoderma strains isolated from different ecosystems, based on their morphological properties and restriction analysis of ITS fragments. The fungal growth was tested on potato dextrose agar, amended with Cu(II concentrations ranging from 0.25 to 10 mmol/l, in order to identify copper-resistant strains. The results indicate that some isolated strains of Trichoderma sp. show tolerance to higher copper concentrations. Further research to examine the ability of copper bioaccumulation by tolerant Trichoderma strains is needed. [Projekat Ministarstva nauke Republike Srbije, br. TR 31080 i br. III 43010

  11. LIWU Copper Plans to Get Listed

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>According to recently-released "Notice con-cerning Environmental Protection Checks for IPO of Sichuan LIWU Copper Co., Ltd.", Sichuan LIWU Copper Co., Ltd. (hereinafter referred to as LIWU Copper) plans to issue 68 million shares, and all the funds raised will be

  12. Canine Models for Copper Homeostasis Disorders

    NARCIS (Netherlands)

    Wu, Xiaoyan; Leegwater, Peter A J|info:eu-repo/dai/nl/074236539; Fieten, Hille|info:eu-repo/dai/nl/314112596

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurolog

  13. Extra-Hepatic Storage of Copper

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Damsgaard, Else; Horn, N.

    1975-01-01

    The distribution of copper among the organs of an aborted, male foetus, expected to develop Menkes' syndrome, was entirely different from the distribution in 4 normal foetuses. Copper concentrations determined by neutron activation analysis showed a considerably reduced content in the liver......, but increased concentrations in the other organs analysed; total foetal copper was normal....

  14. Quanwei Copper Processing Base Put Into Operation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>Quanwei (Tongling) Copper Co.,Ltd’s copper processing base in Tongling of Anhui Province has been put into operation at the end of De- cember last year. It is reported that the copper processing project, invested by Zhengwei (Shenzhen) Technology

  15. Study on copper adsorption on olivine

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The copper adsorption on olivine supplied by A/S Olivine production plant at Aheim in western Norway has been studied. The factors which affect the uptake of copper have been evaluated. The results reveal that the equilibrium pH in aqueous solution has the greatest influence on the copper adsorption thanks to the competitive adsorption between proton and copper ions, and the adsorption of copper to olivine increases rapidly with the pH increasing from 4 to 6. The initial copper concentration and olivine dose also possess significant effect on copper adsorption. The adsorption efficieny of copper increases with the increase of olivine dose or the decrease of initial copper concentration at the same pH. The ionic strength effect on the adsorption has also been investigated, but it owns little effect on the adsorption process of copper due to the formation of inner sphere surface complexation of copper on olivine. The experimental data show that olivine has a high acid buffer capacity and is an effective adsorbent for copper.

  16. Canine Models for Copper Homeostasis Disorders

    NARCIS (Netherlands)

    Wu, Xiaoyan; Leegwater, Peter A J; Fieten, Hille

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurolog

  17. Preparation of Copper-loaded Microcapsule Formulations

    Directory of Open Access Journals (Sweden)

    Nenad Jalšenjak

    2011-06-01

    Full Text Available Novel copper-loaded chitosan or chitosan/alginate based microcapsules formulations have been presented. It was shown that prolonged release of copper from microcapsules accompanied with possible prolonged presence of copper on leaves is useful in crop protection.

  18. Preparation of Copper-loaded Microcapsule Formulations

    Directory of Open Access Journals (Sweden)

    Nenad Jalšenjak

    2014-02-01

    Full Text Available Novel copper-loaded chitosan or chitosan/alginate based microcapsules formulations have been presented. It was shown that prolonged release of copper from microcapsules accompanied with possible prolonged presence of copper on leaves is useful in crop protection.

  19. Canine Models for Copper Homeostasis Disorders

    NARCIS (Netherlands)

    Wu, Xiaoyan; Leegwater, Peter A J; Fieten, Hille

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and

  20. Copper coating specification for the RHIC arcs

    Energy Technology Data Exchange (ETDEWEB)

    Blaskiewicz, M.

    2010-12-01

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

  1. Distribution of Copper in Rats Submitted to Treatment With Copper Aspirinate

    OpenAIRE

    LIU, Weiping; Yang, Yikun; Xiong, Huizhou; Lu, Ying; Yang, Rong

    1998-01-01

    The distribution of copper in Sprague – Dawley rats following a three month oral administration of 0,10 or 50mg/kg copper aspirinate has been investigated. Metal content was determined by ICP – AES in blood, brain, kidney, liver, lung, spleen, and dejection. The results show that treatment with copper aspirinate did not cause accumulation of copper in rats and excess ingested copper was excreted through feces.

  2. Chinalco Straightened Out Copper Assets, and Delegated Stock Equity of Yunnan Copper

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>Immediately after the news that Chinalco transferred 58%stock equity of Yunnan Copper Group to its wholly-owned subsidiary China Copper Corporation Limited free of charge was disclosed on July 9,many individual investors couldn’t help but to think:Does it mean China Copper Corporation Limited will assemble assets for overall listing?At present,among main copper business companies under China Copper Corporation

  3. A copper vapor laser by using a copper-vapor-complex reaction at a low temperature

    OpenAIRE

    Kano, Toshiyuki; Taniguchi, Hiroshi; Saito, Hiroshi

    1987-01-01

    A copper vapor laser performance by using ametal-vapor-complex reaction (Cu+AlBr3) is reported. The laser operation is obtained at a low temperature without externalheating because of the AlBr3 vapors evaporating at a room temperature. The copper vapor laser using this metal-vapor-complex reaction has an advantage of deposition-free of a metallic copper to the laser tube wall, which is different from the copper halide and the organometallic copper lasers.

  4. Copper metabolism and copper-mediated alterations in the metabolism of cultured astrocytes

    OpenAIRE

    Scheiber, Ivo Florin

    2012-01-01

    Copper is an essential element that is required for a variety of important cellular functions. Since not only copper deficiency, but also excess of copper can seriously affect cellular functions, cellular copper metabolism is tightly regulated. Disturbances of copper homeostasis are the underlying defect of the inherited diseases Menkes and Wilson s disease and have also been linked to several neurodegenerative diseases including Alzheimer s disease and Parkinson s disease. Known astrocytes f...

  5. Complex electronic waste treatment - An effective process to selectively recover copper with solutions containing different ammonium salts.

    Science.gov (United States)

    Sun, Z H I; Xiao, Y; Sietsma, J; Agterhuis, H; Yang, Y

    2016-11-01

    Recovery of valuable metals from electronic waste has been highlighted by the EU directives. The difficulties for recycling are induced by the high complexity of such waste. In this research, copper could be selectively recovered using an ammonia-based process, from industrially processed information and communication technology (ICT) waste with high complexity. A detailed understanding on the role of ammonium salt was focused during both stages of leaching copper into a solution and the subsequent step for copper recovery from the solution. By comparing the reactivity of the leaching solution with different ammonium salts, their physiochemical behaviour as well as the leaching efficiency could be identified. The copper recovery rate could reach 95% with ammonium carbonate as the leaching salt. In the stage of copper recovery from the solution, electrodeposition was introduced without an additional solvent extraction step and the electrochemical behaviour of the solution was figured out. With a careful control of the electrodeposition conditions, the current efficiency could be improved to be 80-90% depending on the ammonia salts and high purity copper (99.9wt.%). This research provides basis for improving the recyclability and efficiency of copper recovery from such electronic waste and the whole process design for copper recycling.

  6. Enriching and Separating Primary Copper Impurity from Pb-3 Mass Pct Cu Melt by Super-Gravity Technology

    Science.gov (United States)

    Yang, Yuhou; Song, Bo; Song, Gaoyang; Yang, Zhanbing; Xin, Wenbin

    2016-10-01

    In this study, super-gravity technology was introduced in the lead bullion-refining process to investigate the enriching and separating laws of copper impurity from Pb-3 mass pct Cu melt. With the gravity coefficient G = 700 at the cooling rate of ν = 5 K min-1, the entire copper phase gathers at the upper area of the sample, and it is hard to find any copper particles at the bottom area of the sample. The floatation movement of copper phase was greatly intensified by super gravity and the mass pct of copper in tailing lead is up to 8.631 pct, while that in the refined lead is only 0.113 pct. The refining rate of lead bullion reached up to 94.27 pct. Copper-phase impurity can be separated effectively from Pb-3 mass pct Cu melt by filtration method in super-gravity field, and the separation efficiency increased with the increasing gravity coefficient in the range of G ≥ 10. After filtration at 613 K (340 °C) with gravity coefficient G = 100 for 10 minutes, the refined lead, with just 0.157 mass pct copper impurity, was separated to the bottom of the crucible, and the copper dross containing only 23.56 mass pct residual lead was intercepted by the carbon fiber felt, leading to the separation efficiency up to 96.18 pct (meaning a great reduction in metal loss).

  7. Preparation of asymmetrically distributed bimetal ceria (CeO₂) and copper (Cu) nanoparticles in nitrogen-doped activated carbon micro/nanofibers for the removal of nitric oxide (NO) by reduction.

    Science.gov (United States)

    Bhaduri, Bhaskar; Verma, Nishith

    2014-12-15

    A novel multi-scale web of carbon micro/nanofibers (ACF/CNF) was prepared by the catalytic chemical vapor deposition (CCVD), in which CeO2 and Cu nanoparticles (NPs) were in-situ incorporated during a synthesis step. The CVD temperature was adjusted such that the prepared material had asymmetric distribution of the bimetals, with the Cu NPs located at the tips of the CNFs and the CeO2 particles adhered to the surface of the ACF substrate. The prepared bimetals-dispersed web of ACF/CNF was treated with pyridine and the surface functionalized material was applied for the removal of NO by reduction. The complete reduction of NO was achieved at 500°C and for 400ppm NO concentration. Whereas the Cu NPs acted as the catalyst for the reduction, CeO2 facilitated the incorporation of nitrogen from the pyridine source into the ACF/CNF surface. The produced nitrogen containing surface functional groups enhanced the reactivity of the material toward the NO. The bimetals CeO2 and Cu nanoparticles (NPs)-dispersed ACF/CNF produced in this study is a potential candidate for effectively removing NO by reduction, without requiring urea or ammonia used in conventional abatement methods. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Electrochemical nucleation and growth of copper and copper alloys

    Science.gov (United States)

    Shao, Wenbo

    This dissertation aims to contribute to a fundamental understanding of the physicochemical processes occurring in electrochemical nucleation and growth. To this end, the effects of various anions (chloride (Cl-), sulfate (SO42-) and sulfamate (NH2SO 3-)) on the electrochemical kinetics and the mechanism of copper reduction, as well as on the microstructure of the resulting films, were studied. On the basis of this work, the deposition of copper alloys (Cu-Ag with positive heat of mixing, Cu-Au with negative heat of mixing) was investigated with the main objective to achieve an insight on the role of solid state thermodynamics on the electrocrystallization process. Chloride ions cause two competing effects: at low chloride concentration the formation of an adsorbed chloride layer introduces an additional reaction pathway, resulting in an overall depolarization of the reduction process with no significant change of the Tafel slope. At high chloride concentration, complexation phenomena induce a cathodic polarization of the deposition process and a decrease in the Tafel slope. Chlorides cause a decrease in the density and an increased size of copper nuclei. Sulfamate depolarizes copper reduction the most and results in the largest nucleus density. Chloride promotes the faceting, and dendritic growth of copper deposits along direction by introducing interfacial anisotropy. Addition of Ag in the solution or in the electrode substrate enhances copper deposition and results in an additional reduction peak. Codeposition of Cu-Ag increases nucleus density and decreases nucleus size. Such enhancement of copper deposition, the increase in nucleus density and the decrease in nucleus size by Ag could be due to the continued formation of a surface alloy of Cu-Ag and the fast interface dynamics of Ag deposition. Cu can be underpotentially codeposited in the Cu-Au alloy. Homogeneous solid solutions are grown under conditions of underpotential deposition of Cu, while precipitation

  9. Evaluation of electrode materials for all-copper hybrid flow batteries

    Science.gov (United States)

    Leung, Puiki; Palma, Jesus; Garcia-Quismondo, Enrique; Sanz, Laura; Mohamed, M. R.; Anderson, Marc

    2016-04-01

    This work evaluates a number of two- and three-dimensional electrodes for the reactions of an all-copper hybrid flow battery. Half- and full-cell experiments are conducted by minimizing the crossover effect of the copper(II) species. The battery incorporates a Nafion® cation exchange membrane and the negative electrolyte is maintained at the monovalent (colourless) state by the incorporating copper turnings in the electrolyte reservoir. Under such conditions, the half-cell coulombic efficiencies of the negative electrode reactions are all higher than 90% regardless of electrode materials and the state-of-charge (SOC). With charge-discharge cycling the half-cell from a 0% SOC, the coulombic efficiencies of the positive electrode reactions are lower than 76% with the planar carbon electrode, which further decrease in shorter charge-discharge cycles. Polarization and half-cell charge-discharge experiments suggest that the high-surface-area electrodes effectively reduce the overpotentials and improve the coulombic efficiencies of both electrode reactions. When copper fibres and carbon felt are used as the negative and positive electrodes, the average coulombic and voltage efficiencies of an all-copper flow battery are as high as c.a. 99% and c.a. 60% at 50 mA cm-2 for 35 cycles.

  10. Electrochemical behaviour of alkaline copper complexes

    Indian Academy of Sciences (India)

    C L Aravinda; S M Mayanna; V R Muralidharan

    2000-10-01

    A search for non-cyanide plating baths for copper resulted in the development of alkaline copper complex baths containing trisodium citrate [TSC] and triethanolamine [TEA]. Voltammetric studies were carried out on platinum to understand the electrochemical behaviour of these complexes. In TSC solutions, the deposition of copper involves the slow formation of a monovalent species. Adsorption of this species obeys Langmuir isotherm. In TEA solutions the deposition involves the formation of monovalent ions obeying the non-activated Temkin isotherm. Conversion of divalent to monovalent copper is also slow. In TEA and TSC alkaline copper solutions, the predominant species that undergo stepwise reduction contain only TEA ligands

  11. Exopolysaccharides favor the survival of Erwinia amylovora under copper stress through different strategies.

    Science.gov (United States)

    Ordax, Mónica; Marco-Noales, Ester; López, María M; Biosca, Elena G

    2010-09-01

    Erwinia amylovora causes fire blight, a destructive disease of rosaceous plants very difficult to control. We demonstrated that copper, employed to control plant diseases, induces the "viable-but-nonculturable" (VBNC) state in E. amylovora. Moreover, it was previously reported that copper increases production of its main exopolysaccharide (EPS), amylovoran. In this work, the copper-complexing ability of amylovoran and levan, other major EPS of E. amylovora, was demonstrated. Following this, EPS-deficient mutants were used to determine the role of these EPSs in survival of this bacterium in AB mineral medium with copper, compared to their wild type strain and AB without copper. Total, viable and culturable counts of all strains were monitored for six months. With copper, a larger fraction of the viable population of EPS mutants entered into the VBNC state, and earlier than their wild type strain, showing the contribution of both EPSs to long-term survival in a culturable state. Further, we demonstrated that both EPSs can be used as carbon source by E. amylovora under deprivation conditions. Overall, these previously unreported functions of amylovoran and levan provide survival advantages for E. amylovora, which could contribute to its enhanced persistence in nature.

  12. Study on copper complexing ligand concentrations in several China's coastal waters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regularity and the relationship with other parameters were discussed. The results were as follows: Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas, and they were apparently higher than those of the ocean. Compared with the subsurface layer (SSL) in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon, of which the mechanism is similar to dissolved organic matter. The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest, then it decreased with depth accruing, and a higher value appeared at the bottom. Copper complexing ligand concentrations were higher than those of cadmium and lead. Ligands in each sea area exhibited a complicated property. In short, the distribution regularity of copper complexing ligand concentrations in China' s coastal waters was consistent with that of other regions in the world. Meanwhile, the positive relationship between the copper complexing ligand concentrations and biological oxygen demand, chemical oxygen demand, dissolved organic carbon, and viscosity were found clearly.

  13. In situ removal of copper from sediments by a galvanic cell.

    Science.gov (United States)

    Yuan, Songhu; Wu, Chan; Wan, Jinzhong; Lu, Xiaohua

    2009-01-01

    This study dealt with in situ removal of copper from sediments through an electrokinetic (EK) process driven by a galvanic cell. Iron (Fe) and carbon (C) were placed separately and connected with a conductive wire. Polluted sediments were put between them and water was filled above the sediments. The galvanic cell was thus formed due to the different electrode potentials of Fe and C. The cell could remove the pollutants in the sediments by electromigration and/or electroosmosis. Results showed that a weak voltage less than 1V was formed by the galvanic cell. The voltage decreased with the increase of time. A slight increase of sediment pH from the anode (Fe) to the cathode (C) was observed. The presence of supernatant water inhibited the variation of sediment pH because H(+) and OH(-) could diffuse into the water. The removal of copper was affected by the sediment pH and the distribution of electrolyte in sediment and supernatant water. Lower pH led to higher removal efficiency. More electrolyte in the sediment and/or less electrolyte in the supernatant water favored the removal of copper. The major removal mechanism was proposed on the basis of the desorption of copper from sediment to pore solution and the subsequent electromigration of copper from the anode to the cathode. The diffusion of copper from sediment to supernatant water was negligible.

  14. Crystallization of copper metaphosphate glass

    Science.gov (United States)

    Bae, Byeong-Soo; Weinberg, Michael C.

    1993-01-01

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

  15. Spectroscopic studies of copper enzymes

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-05-01

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

  16. Copper complexes as chemical nucleases

    Indian Academy of Sciences (India)

    Akhil R Chakravarty; Pattubala A N Reddy; Bidyut K Santra; Anitha M Thomas

    2002-08-01

    Redox active mononuclear and binuclear copper(II) complexes have been prepared and structurally characterized. The complexes have planar N-donor heterocyclic bases like 1,10-phenanthroline (phen), dipyridoquinoxaline (dpq) and dipyridophenazine (dppz) ligands that are suitable for intercalation to B-DNA. Complexes studied for nuclease activity have the formulations [Cu(dpq)2(H2O)] (ClO4)2.H2O (1), [{CuL(H2O)}2(-ox)](ClO4)2 (L = bpy, 2; phen, 3; dpq, 4; and dppz, 5) and [Cu(L)(salgly)] (L = bpy, 6; phen, 7; dpq, 8; and dppz, 9), where salgly is a tridentate Schiff base obtained from the condensation of glycine and salicylaldehyde. The dpq complexes are efficient DNA binding and cleavage active species. The dppz complexes show good binding ability but poor nuclease activity. The cleavage activity of the bis-dpq complex is significantly higher than the bis-phen complex of copper(II). The nuclease activity is found to be dependent on the intercalating nature of the complex and on the redox potential of the copper(II)/copper(I) couple. The ancillary ligand plays a significant role in binding and cleavage activity.

  17. Copper proteomes, phylogenetics and evolution.

    Science.gov (United States)

    Decaria, Leonardo; Bertini, Ivano; Williams, Robert J P

    2011-01-01

    This paper is a continuation of our study of the connection between the changing environment and the changing use of particular elements in organisms in the course of their combined evolution (Decaria, Bertini and Williams, Metallomics, 2010, 2, 706). Here we treat the changes in copper proteins in historically the same increasingly oxidising environmental conditions. The study is a bioinformatic analysis of the types and the numbers of copper domains of proteins from 435 DNA sequences of a wide range of organisms available in NCBI, using the method developed by Andreini, Bertini and Rosato in Accounts of Chemical Research 2009, 42, 1471. The copper domains of greatest interest are found predominantly in copper chaperones, homeostatic proteins and redox enzymes mainly used outside the cytoplasm which are in themselves somewhat diverse. The multiplicity of these proteins is strongly marked. The contrasting use of the iron and heme iron proteins in oxidations, mostly in the cytoplasm, is compared with them and with activity of zinc fingers during evolution. It is shown that evolution is a coordinated development of the chemistry of elements with use of novel and multiple copies of their proteins as their availability rises in the environment.

  18. CopperCore Service Integration

    Science.gov (United States)

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

    2007-01-01

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

  19. Preparation of Carbon Nanotubes from Methane on Ni/Cu/A1 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Renzhong Wei; Fengyi Li; Yan Ju

    2005-01-01

    A series of Ni/Cu/Al catalyst samples were prepared by the co-precipitation method. Carbon nanotubes with large inner diameters are successfully synthesized from methane on Ni/Cu/Al catalyst by adding sodium carbonate. The effects of the copper content and amounts of sodium carbonate on the morphology and microstructures of carbon nanotubes were investigated by CO adsorption and TEM technique. The experimental results showed that copper can influence both the catalytic activity and catalyst life. Best result was obtained when the copper content was 15%. Addition of sodium carbonate favors the formation of carbon nanotubes with large inner diameters. The growth mechanism of carbon nanotubes with large inner diameter is discussed.

  20. Reactivity test between beryllium and copper

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, H. [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan); Kato, M. [NGK Insulators, Ltd., Aichi-ken (Japan)

    1995-09-01

    Beryllium has been expected for using as plasma facing material on ITER. And, copper alloy has been proposed as heat sink material behind plasma facing components. Therefore, both materials must be joined. However, the elementary process of reaction between beryllium and copper alloy does not clear in detail. For example, other authors reported that beryllium reacted with copper at high temperature, but it was not obvious about the generation of reaction products and increasing of the reaction layer. In the present work, from this point, for clarifying the elementary process of reaction between beryllium and copper, the out-of-pile compatibility tests were conducted with diffusion couples of beryllium and copper which were inserted in the capsule filled with high purity helium gas (6N). Annealing temperatures were 300, 400, 500, 600 and 700{degrees}C, and annealing periods were 100, 300 and 1000h. Beryllium specimens were hot pressed beryllium, and copper specimens were OFC (Oxygen Free Copper).