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Sample records for thick-wall copper electron

  1. Technical assistance to AECL: electron beam welding of thick-walled copper containers for nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Maak, P.Y.Y.

    1984-01-01

    This report describes the results of Phase Two of the copper electron beam welding project for the final closure of copper containers for nuclear fuel waste disposal. It has been demonstrated that single pass, electron beam square butt welds (depth of weld penetration > 25 mm) can be made without preheat in both electrolytic tough-pitch copper and oxygen-free copper plates. The present results show that oxygen-free copper exhibits better weldability than the electrolytic tough-pitch copper in terms of weld penetration and vulnerability to weld defects such as gas porosity, erratic metal overflow and blow holes. The results of ultrasonic inspection studies of the welds are also discussed

  2. Electronics scrap processing at Brixlegg copper works

    Energy Technology Data Exchange (ETDEWEB)

    Kaltenboeck, F.J.; Sauer, E.; Woebking, H.; Woerz, H.

    1985-11-01

    The valuable metals - in particular precious metals, copper, zinc, and tin - that are included in electronics scraps are recovered in the secondary copper works of Brixlegg in the form of commercial intermediate products or in the form of pure metals. The refinery line is as follows: shaft furnace, converter, anode furnace, electrolytic copper refinery and slime plants for precious metal recovery from anode slimes. (orig.).

  3. Investigation of torsional vibrations in thick walled hollow poroelastic ...

    Indian Academy of Sciences (India)

    Abstract. This paper deals with the study of torsional vibrations of thick walled hollow poroelastic cylinder using Biot's extension theory. Considering the boundaries to be stress free, the frequency equation is obtained in the presence of dissipation which is transcendental and complex valued in nature. In the special case of ...

  4. Bioremediation: Copper Nanoparticles from Electronic-waste

    OpenAIRE

    D. R. MAJUMDER

    2012-01-01

    A single-step eco-friendly approach has been employed to synthesize copper nanoparticles. The superfast advancement in the field of electronics has given rise to a new type of waste called electronic waste. Since the physical and chemical recycling procedures have proved to be hazardous, the present work aims at the bioremediation of e-waste in order to recycle valuable metals. Microorganisms such as Fusarium oxysporum and Pseudomonas sp. were able to leach copper (84-130 nm) from integrated ...

  5. Development of thick wall welding and cutting tools for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Nakahira, Masataka; Takahashi, Hiroyuki; Akou, Kentaro; Koizumi, Koichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-04-01

    The Vacuum Vessel, which is a core component of International Thermonuclear Experimental Reactor (ITER), is required to be exchanged remotely in a case of accident such as superconducting coil failure. The in-vessel components such as blanket and divertor are planned to be exchanged or fixed. In these exchange or maintenance operations, the thick wall welding and cutting are inevitable and remote handling tools are necessary. The thick wall welding and cutting tools for blanket are under developing in the ITER R and D program. The design requirement is to weld or cut the stainless steel of 70 mm thickness in the narrow space. Tungsten inert gas (TIG) arc welding, plasma cutting and iodine laser welding/cutting are selected as primary option. Element welding and cutting tests, design of small tools to satisfy space requirement, test fabrication and performance tests were performed. This paper reports the tool design and overview of welding and cutting tests. (author)

  6. Electron impact single ionization of copper

    Indian Academy of Sciences (India)

    Electron impact single ionization cross sections of copper have been calculated in the binary encounter approximation using accurate expression for as given by Vriens and Hartree–Fock momentum distribution for the target electron. The BEA calculation based on the usual procedure does not show satisfactory ...

  7. Relaxation of Thick-Walled Cylinders and Spheres

    DEFF Research Database (Denmark)

    Saabye Ottosen, N.

    1982-01-01

    Using the nonlinear creep law proposed by Soderberg, (1936) closed-form solutions are derived for the relaxation of incompressible thick-walled spheres and cylinders in plane strain. These solutions involve series expressions which, however, converge very quickly. By simply ignoring these series...... expressions, extremely simple approximate solutions are obtained. Despite their simplicity these approximations possess an accuracy that is superior to approximations currently in use. Finally, several physical aspects related to the relaxation of cylinders and spheres are discussed...

  8. Studying energy absorption in tapered thick walled tubes

    Directory of Open Access Journals (Sweden)

    P. Hosseini Tehrani

    Full Text Available In many engineering structures different energy absorption systems may be used to improve crashworthiness capability of the system and to control damages that may occur in a system during an accident. Therefore, extensive research has been done on the energy-absorbing cells. In this paper, energy absorption in tapered thick walled tubes has been investigated. As a practical case, studies have been focused on the crush element of Siemens ER24PC locomotive. To investigate performance of this part at collision time, it has been modeled in Abaqus software and its collision characteristics have been evaluated. Considering that the crash element is folded at time of collision, an analytical approach has been presented for calculation of instantaneous folding force under axial load. Basis of this method is definition and analysis of main folding mechanism and calculation of average folding force. This method has been used for validation of the results of numerical solution. Since sheet thickness of the crash element is high and may be ruptured at time of collision, some damage models have been used for numerical simulations. One of the three damage models used in this paper is available in the software and coding has been done for two other damage models and desirable damage model has been specified by comparing results of numerical solution with results of laboratory test. In addition, authenticity of the desirable damage model has been studied through ECE R 66 standard. To improve crashworthiness characteristic some attempts, such as use of metal foam and creation of trigger in suitable situations to reduce maximum force resulting from collision, have been performed. Finally though different simulation optimal crush element has been introduced and its performance and efficiency have been evaluated.

  9. Patterned electrochemical deposition of copper using an electron beam

    Directory of Open Access Journals (Sweden)

    Mark den Heijer

    2014-02-01

    Full Text Available We describe a technique for patterning clusters of metal using electrochemical deposition. By operating an electrochemical cell in the transmission electron microscope, we deposit Cu on Au under potentiostatic conditions. For acidified copper sulphate electrolytes, nucleation occurs uniformly over the electrode. However, when chloride ions are added there is a range of applied potentials over which nucleation occurs only in areas irradiated by the electron beam. By scanning the beam we control nucleation to form patterns of deposited copper. We discuss the mechanism for this effect in terms of electron beam-induced reactions with copper chloride, and consider possible applications.

  10. Intense pulsed light sintering of copper nanoink for printed electronics

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hak-Sung; Dhage, Sanjay R.; Shim, Dong-Eun [University of California, Mechanical and Aerospace Engineering Department, Los Angeles, CA (United States); Hahn, H.T. [University of California, Mechanical and Aerospace Engineering Department, Los Angeles, CA (United States); University of California, Material Science and Engineering Department, California NanoSystems Institute, Los Angeles, CA (United States)

    2009-12-15

    An intense pulsed light (IPL) from a xenon flash lamp was used to sinter copper nanoink printed on low-temperature polymer substrates at room temperature in ambient condition. The IPL can sinter the copper nanoink without damaging the polymer substrates in extremely short time (2 ms). The microstructure of the sintered copper film was investigated using X-ray powder diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), X-ray micro tomography, and atomic force microscopy (AFM). The sintered copper film has a grainy structure with neck-like junctions. The resulting resistivity was 5{mu}{omega} cm of electrical resistivity which is only 3 times as high as that of bulk copper. The IPL sintering technique allows copper nanoparticles to be used in inkjet printing on low-temperature substrates such as polymers in ambient conditions. (orig.)

  11. The Bulging Behavior of Thick-Walled 6063 Aluminum Alloy Tubes Under Double-Sided Pressures

    Science.gov (United States)

    Cui, Xiao-Lei; Wang, Xiao-Song; Yuan, Shi-Jian

    2015-05-01

    To make further exploration on the deformation behavior of tube under double-sided pressures, the thick-walled 6063 aluminum alloy tubes with an outer diameter of 65 mm and an average thickness of 7.86 mm have been used to be bulged under the combined action of internal and external pressures. In the experiment, two ends of the thick-walled tubes were fixed using the tooth and groove match. Three levels of external pressure (0 MPa, 40 MPa, and 80 MPa), in conjunction with the internal pressure, were applied on the tube outside and inside simultaneously. The effect of external pressure on the bulging behavior of the thick-walled tubes, such as the limiting expansion ratio, the bulging zone profile, and the thickness distribution, has been investigated. It is shown that the limiting expansion ratio, the bulging zone profile, and the thickness distribution in the homogeneous bulging area are all insensitive to the external pressure. However, the external pressure can make the thick-walled tube achieve a thinner wall at the fracture area. It reveals that the external pressure can only improve the fracture limit of the thick-walled 6063 tubes, but it has very little effect on their homogeneous bulging behavior. It might be because the external pressure can only increase the magnitude of the hydrostatic pressure for the tube but has no effect on the Lode parameter.

  12. Optimized thick-wall cylinders by virtue of Poisson's ratio selection

    International Nuclear Information System (INIS)

    Whitty, J.P.M.; Henderson, B.; Francis, J.; Lloyd, N.

    2011-01-01

    The principal stress distributions in thick-wall cylinders due to variation in the Poisson's ratio are predicted using analytical and finite element methods. Analyses of appropriate brittle and ductile failure criteria show that under the isochoric pressure conditions investigated that auextic (i.e. those possessing a negative Poisson's ratio) materials act as stress concentrators; hence they are predicted to fail before their conventional (i.e. possessing a positive Poisson's ratio) material counterparts. The key finding of the work presented shows that for constrained thick-wall cylinders the maximum tensile principal stress can vanish at a particular Poisson's ratio and aspect ratio. This phenomenon is exploited in order to present an optimized design criterion for thick-wall cylinders. Moreover, via the use of a cogent finite element model, this criterion is also shown to be applicable for the design of micro-porous materials.

  13. Facilitating protein crystal cryoprotection in thick-walled plastic capillaries by high-pressure cryocooling

    OpenAIRE

    Chen, Yi-Fan; Tate, Mark W.; Gruner, Sol M.

    2009-01-01

    The minimal concentrations of three common cryoprotectants were determined for high-pressure cryocooling of water in thick-walled plastic capillaries. The substantial reduction in the minimal concentrations by high-pressure cryocooling can be of significant use in high-throughput X-ray protein structure determination.

  14. Development of automated welding process for field fabrication of thick walled pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, U A

    1981-01-01

    Research on automatic welding processes for the fabrication of thick-walled pressure vessels continued. A literature review on the subject was completed. A laboratory study of criteria for judging acceptable root parameters continued. Equipment for a demonstration facility to test the components and processes of the automated welding system has been specified and is being obtained. (LCL)

  15. Electron beam hardening type copper plate printing ink

    International Nuclear Information System (INIS)

    Kawamura, Eiji; Inoue, Mitsuo; Kusaki, Satoichiro

    1989-01-01

    Copper plate printing is the printing method of filling ink in the parts of concave printing elements on a type area, and transferring the ink to a base, and it is the feature that the ink in the printing element parts of a print rises. Copper plate prints show profound feeling, in addition, its effect of preventing forgery is high. This method is generally called engraving printing, and is used frequently for printing various bills and artistic prints. The electron beam irradiation apparatus installed in the laboratory of the Printing Bureau, Ministry of Finance, is an experimental machine of area beam type, and is so constructed as to do batch conveyance and web conveyance. As the ink in printing element parts rises, the offset at the delivery part of a printing machine becomes a problem. Electron beam is superior in its transparency, and can dry instantaneously to the inside of opaque ink. At 200 kV of acceleration voltage, the ink of copper plate prints can be hardened by electron beam irradiation. The dilution monomers as the vehicle for ink were tested for their dilution capability and the effect of electron beam hardening. The problem in the utilization of electron beam is the deterioration of papers, and the counter-measures were tested. (K.I.)

  16. Accuracy of thick-walled hollows during piercing on three-high mill

    International Nuclear Information System (INIS)

    Potapov, I.N.; Romantsev, B.A.; Shamanaev, V.I.; Popov, V.A.; Kharitonov, E.A.

    1975-01-01

    The results of investigations are presented concerning the accuracy of geometrical dimensions of thick-walled sleeves produced by piercing on a 100-ton trio screw rolling mill MISiS with three schemes of fixing and centering the rod. The use of a spherical thrust journal for the rod and of a long centering bushing makes it possible to diminish the non-uniformity of the wall thickness of the sleeves by 30-50%. It is established that thick-walled sleeves with accurate geometrical dimensions (nonuniformity of the wall thickness being less than 10%) can be produced if the system sleeve - mandrel - rod is highly rigid and the rod has a two- or three-fold stability margin over the length equal to that of the sleeve being pierced. The process of piercing is expedient to be carried out with increased angles of feed (14-16 deg). Blanks have been made from steel 12Kh1MF

  17. Creep collapse of thick-walled heat transfer tube subjected to external pressure at high temperature

    International Nuclear Information System (INIS)

    Ioka, Ikuo; Kaji, Yoshiyuki; Terunuma, Isao; Nekoya, Shin-ichi; Miyamoto, Yoshiaki

    1994-09-01

    A series of creep collapse tests of thick-walled heat transfer tube were examined experimentally and analytically to confirm an analytical method for creep deformation behavior of a heat transfer tube of an intermediate heat exchanger (IHX) at a depressurization accident of secondary cooling system of HTTR (High Temperature Engineering Test Reactor). The tests were carried out using thick-walled heat transfer tubes made of Hastelloy XR at 950degC in helium gas environment. The predictions of creep collapse time obtained by a general purpose FEM-code ABAQUS were in good agreement with the experimental results. A lot of cracks were observed on the outer surface of the test tubes after the creep collapse. However, the cracks did not pass through the tube wall and, therefore, the leak tightness was maintained regardless of a collapse deformation for all tubes tested. (author)

  18. Creep properties in similar weld joint of a thick-walled P92 steel pipe

    Czech Academy of Sciences Publication Activity Database

    Sklenička, Václav; Kuchařová, Květa; Svobodová, M.; Kvapilová, Marie; Král, Petr; Horváth, P.

    2016-01-01

    Roč. 119, č. 1 (2016), s. 1-12 ISSN 1044-5803 R&D Projects: GA ČR(CZ) GA16-09518S; GA MPO FR-TI4/406 Institutional support: RVO:68081723 Keywords : 9–12%Cr steels * Creep testing * High temperature creep * Thick-walled pipe * Welding Subject RIV: JG - Metallurgy Impact factor: 2.714, year: 2016

  19. Collapsing of Thick-Walled Cylinders Using Electro-Magnetic Driving Forces

    Science.gov (United States)

    Lovinger, Zev; Rikanati, Avi; Rittel, Daniel; Rosenberg, Zvi

    2009-06-01

    The Thick-Walled Cylinder technique, reported in the literature, uses explosive loading to enforce collapsing of the cylindrical sample. This experimental set-up has been established as a controlled and repeatable technique to create and study multiple adiabatic shear bands. Searching to establish a simpler experimental platform to perform large sets of experiments, we have designed an Electro-Magnetic (EM) set-up for the collapsing of thick walled cylinders. The EM set-up is based on a pulsed current generator using a capacitor bank system. The specimen is an assembly of coaxial cylinders, where the inner and outer cylinders, each attached to an opposite pole, are short-circuited. Upon discharge, a high current flows through the cylinders, in opposite directions, creating repulsive magnetic forces between them. This work presents the design procedure of the specimens using numerical simulations and some experimental results for SS304L thick-walled samples, using this set-up. The spatial distribution of the multiple adiabatic shear bands in these experiments is in good agreement with that reported in the literature for the explosive driven experiments with a similar material.

  20. Review of electron impact excitation cross sections for copper atom

    Energy Technology Data Exchange (ETDEWEB)

    Winter, N.W.; Hazi, A.U.

    1982-02-01

    Excitation of atomic copper by electron impact plays an important role in the copper vapor laser and accurate cross sections are needed for understanding and modeling laser performance. During the past seven years, there have been several attempts to normalize the relative elastic and inelastic cross sections measured by Trajmar and coworkers. However, each of these efforts have yielded different cross sections, and the uncertainty in the correct normalization of the data has been a source of confusion and concern for the kinetic modeling efforts. This difficulty has motivated us to review previous work on the electron impact excitation of copper atom and to perform new calculations of the inelastic cross sections using the impact parameter method. In this memorandum we review the previous attempts to normalize the experimental data and provide a critical assessment of the accuracy of the resulting cross sections. We also present new theoretical cross sections for the electron impact excitation of the /sup 2/S ..-->.. /sup 2/P/sup 0/ and /sup 2/S ..-->.. /sup 2/D transitions in copper. When the experimental cross sections are renormalized to the results of the impact parameter calculations, they are a factor of three smaller than those published in the latest paper of Trajmar et. al. At impact energies above 60 eV the excitation cross sections obtained with the impact parameter method agree well with the results of the very recent, unpublished, close-coupling calculations of Henry. This agreement suggests that the present normalization of the experimental cross sections is probably the most reliable one obtained to date.

  1. Determination of the Electron Self-Exchange Rates of Blue Copper Proteins by Super-WEFT NMR Spectroscopy

    DEFF Research Database (Denmark)

    Ma, Lixin; Philipp, Else Astrid; Led, Jens J.

    2001-01-01

    Anabaena variabilis plastocyanin, blue copper proteins, electron self-exchange rates, electron transfer, super-WEFT NMR......Anabaena variabilis plastocyanin, blue copper proteins, electron self-exchange rates, electron transfer, super-WEFT NMR...

  2. High performance 3D printed electronics using electroless plated copper

    Directory of Open Access Journals (Sweden)

    Jin Rong Jian

    2017-03-01

    Full Text Available This paper presents design and performance validation of 3D printed electronic components, 3D toroidal air-core inductors, fabricated by multi-material based Fused Deposition Modelling (FDM 3D printing technology and electroless copper plating. Designs of toroidal inductor is investigated with different core shapes and winding numbers; circular and half-circular cores with 10 and 13 turns of windings. Electroless plated copper thin film ensures 3D printed toroidal plastic structures to possess inductive behaviors. The inductance is demonstrated reliably with an applied source frequency from 100 kHz to 2 MHz as designs vary. An RL circuit is utilized to test the fabricated inductors’ phase-leading characteristics with corresponding phase angle changes.

  3. NDE of stresses in thick-walled components by ultrasonic methods

    International Nuclear Information System (INIS)

    Goebbels, K.; Pitsch, H.; Schneider, E.; Nowack, H.

    1985-01-01

    The possibilty of measuring stresses - especially residual stresses - by ultrasonic methods has been presented at the 4th and 5th International Conference on NDE in Nuclear Industry. This contribution now presents results of several applications to thick walled components such as turbines and generators for power plants. The measurement technique using linearly polarized shear waves allows one to characterize the homogeneitry of the residual stress situation along and around cylindrically shaped components. Some important results show that the stress distribution integrated over the cross section of the component has not followed in any case the simple relations derived by stress analysts. Conclusions referring to the stress situation inside the components are discussed

  4. Electron beam welding of high-purity copper accelerator cells

    International Nuclear Information System (INIS)

    Delis, K.; Haas, H.; Schlebusch, P.; Sigismund, E.

    1986-01-01

    The operating conditions of accelerator cells require high thermal conductivity, low gas release in the ultrahigh vacuum, low content of low-melting metals and an extremely good surface quality. In order to meet these requirements, high-purity copper (OFHC, Grade 1, according to ASTM B 170-82 and extra specifications) is used as structural material. The prefabricated components of the accelerator cells (noses, jackets, flanges) are joined by electron beam welding, the weld seam being assessed on the basis of the same criteria as the base material. The welding procedures required depend, first, on the material and, secondly, on the geometries involved. Therefore experimental welds were made first on standardized specimens in order to study the behaviour of the material during electron beam welding and the influence of parameter variations. The welded joints of the cell design were planned on the basis of these results. Seam configuration, welding procedures and the parameters were optimized on components of original geometry. The experiments have shown that high-quality joints of this grade of copper can be produced by the electron beam welding process, if careful planning and preparation of the seams and adequate containment of the welding pool are assured. (orig.)

  5. On what controls the spacing of spontaneous adiabatic shear bands in collapsing thick-walled cylinders

    Directory of Open Access Journals (Sweden)

    Lovinger Zev

    2015-01-01

    Full Text Available Shear bands formation in collapsing thick walled cylinders occurs in a spontaneous manner. The advantage of examining spontaneous, as opposed to forced shear localization, is that it highlights the inherent susceptibility of the material to adiabatic shear banding without prescribed geometrical constraints. The Thick-Walled Cylinder technique (TWC provides a controllable and repeatable technique to create and study multiple adiabatic shear bands. The technique, reported in the literature uses an explosive cylinder to create the driving force, collapsing the cylindrical sample. Recently, we developed an electro-magnetic set-up using a pulsed current generator to provide the collapsing force, replacing the use of explosives. Using this platform we examined the shear band evolution at different stages of formation in 7 metallic alloys, spanning a wide range of strength and failure properties. We examined the number of shear bands and spacing between them for the different materials to try and figure out what controls these parameters. The examination of the different materials enabled us to better comprehend the mechanisms which control the spatial distribution of multiple shear bands in this geometry. The results of these tests are discussed and compared to explosively driven collapsing TWC results in the literature and to existing analytical models for spontaneous adiabatic shear localization.

  6. Simulation of Stress Distribution in a Thick- Walled Bushing Produced by Die-Casting

    Directory of Open Access Journals (Sweden)

    Pisarek B.P.

    2017-12-01

    Full Text Available Metallographic investigations and a computer simulation of stresses in a gravity die-casting bushing were performed. Simulation of the casting process, solidification of the thick-walled bushing and calculations of the stress was performed using MAGMA5.3 software. The size variability of phases κII affecting the formation of phase stresses σf, depending on the location of the metallographic test area, was identified. The distribution of thermal σt and shrinkage stresses σs, depending on the location of the control point SC in the bushing's volume, was estimated. Probably the nature of these stresses will change slightly even after machining. This can cause variations in operating characteristics (friction coefficient, wear. Due to the strong inhomogeneity of the stress distribution in the bushing's casting, it is necessary to perform further tests of the possibility to conduct thermal treatment guaranteeing homogenization of the internal stresses in the casting, as well as to introduce changes in the bushing' s construction and the casting technology. The paper presents the continuation of the results of research aimed at identifying the causes of defects in the thick-walled bushing, die-casting made of CuAl10Fe5Ni5Cr aluminium bronze.

  7. OPTIMIZATION OF INHOMOGENEOUS THICK-WALLED SPHERICAL SHELL IN THE TEMPERATURE FIELD

    Directory of Open Access Journals (Sweden)

    Andreev Vladimir Igorevich

    2012-12-01

    Full Text Available The authors consider the central symmetric problem of the theory of elasticity of inhomogeneous bodies for thick-walled spheres exposed to the external pressure in a stationary temperature field. The essence of the inverse problem lies in the identification of such dependence of the elastic modulus on the radius whereby the stress state of the sphere is the same as the pre-set one. Maximal stresses in thick-walled shells exposed to internal or external pressures occur in the proximity to the internal contour. Thus, destruction in this area is initiated upon the achievement of the limit state, while the rest of the shell is underused. The essence of the problem solved in the paper is the following. The problems are solved using the simultaneous exposure to forces and temperature loads.The two theories of strength are considered at once: a maximum normal stress theory and a maximum shear stress theory. It is proven that according to the first theory maximum stresses in an inhomogeneous shell are 1.35 times smaller than those in the homogeneous shell. The stress reduction rate equals to 2.5, if the maximum shear stress theory is employed. Thus, the introduction of artificial inhomogeneity leads to the optimization of shells by reducing their thickness or increasing loads.

  8. Electronic transport properties of copper and gold at atomic scale

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadzadeh, Saeideh

    2010-11-23

    The factors governing electronic transport properties of copper and gold atomic-size contacts are theoretically examined in the present work. A two-terminal conductor using crystalline electrodes is adopted. The non-equilibrium Green's function combined with the density functional tight-binding method is employed via gDFTB simulation tool to calculate the transport at both equilibrium and non-equilibrium conditions. The crystalline orientation, length, and arrangement of electrodes have very weak influence on the electronic characteristics of the considered atomic wires. The wire width is found to be the most effective geometric aspect determining the number of conduction channels. The obtained conductance oscillation and linear current-voltage curves are interpreted. To analyze the conduction mechanism in detail, the transmission channels and their decomposition to the atomic orbitals are calculated in copper and gold single point contacts. The presented results offer a possible explanation for the relation between conduction and geometric structure. Furthermore, the results are in good agreement with available experimental and theoretical studies. (orig.)

  9. Thick-walled anisotropic elliptic tube analyzed via curvilinear tensor calculus

    Directory of Open Access Journals (Sweden)

    Mareš T.

    2007-10-01

    Full Text Available After a brief introduction into the tensor calculus, the thick-walled anisotropic elliptic tube is analyzed. A procedure of the analysis is described in a stepwise manner. A choice of the appropriate coordinate systems is the first step. The second step consists of the determination of corresponding metric tensors. Then the elasticity tensor of a local orthotropy is transformed into a global computational coordinate system. Next the appropriate Christoffel symbols of the second kind are determined and the total potential energy of the system is expressed. At the end the solution is approximated by a Fourier series and for given geometrical values and loading the numerical results are obtained and graphically represented.It must be said that throughout the calculation the free software only was used and for the numerical operations an old laptop is sufficient. The author regards both the former and the latter as a great advantage of the demonstrated method.

  10. An Analytical Time Domain Solution for the Forced Vibration Analysis of Thick-Walled Cylinders

    Directory of Open Access Journals (Sweden)

    Bashir Movahedian

    Full Text Available Abstract In this paper, we propose a time domain analytical solution for the forced vibration analysis of thick-walled hollow cylinders in presence of polar orthotropy. In this regard, solution of the governing equation is decomposed into two parts. The role of the first one is to satisfy boundary conditions utilizing the method of separation of variables besides of Fourier series expansion of the non-homogenous boundary conditions. The second part has been also expressed as the series of orthogonal characteristic functions with the aim of satisfaction of initial conditions. The proposed analytical solution has been implemented to evaluate the dynamic response of the cylinder in solution of some sample problems which are chosen from previous studies.

  11. Load capacity of a thick-walled cylinder with a radial hole

    Energy Technology Data Exchange (ETDEWEB)

    Laczek, S.; Rys, J. [Institute of Machine Design, Cracow University of Technology, Al. Jana Pawla II 37, 31 864 Krakow (Poland); Zielinski, A.P., E-mail: apz@mech.pk.edu.p [Institute of Machine Design, Cracow University of Technology, Al. Jana Pawla II 37, 31 864 Krakow (Poland)

    2010-08-15

    The paper deals with elastic-plastic analysis of the stress-strain state in the vicinity of a hole in a thick-walled cylindrical pressure vessel. The investigations have been inspired by the phenomenon of ductile fracture observed in a high-pressure reactor. Using finite element calculations, different failure criteria are proposed to aid design and control of high-pressure vessels with piping attachments. They are compared with suggestions of American (ASME) and European (EN) standards. A simple shakedown analysis of the structure is also presented. The local stress distribution near the hole results in a specific failure of the vessel. A plastic zone appears in the vicinity of the internal cylinder surface and propagates along the hole side. The vessel unloading can cause local reverse plasticity, which leads to plastic shakedown in the small zone and then to progressive ductile fracture in this zone. This is dangerous for the whole structure.

  12. The Influence of an Air Exposure on the Secondary Electron Yield of Copper

    OpenAIRE

    Scheuerlein, C; Hilleret, Noël

    1997-01-01

    The influence of different air exposure times on the secondary electron emission of clean copper surfaces as well as on technical copper surfaces has been studied in the context of the phenomenon of multipacting, which can limit the performance of superconducting radio-frequency (RF) cavities for particle acceleration. The copper samples were prepared by heat treatments and in situ sputter-etching and they were investigated with a instrument for SEY measurements, by scanning electron microsco...

  13. Finite element limit loads for non-idealized through-wall cracks in thick-walled pipe

    International Nuclear Information System (INIS)

    Shim, Do-Jun; Han, Tae-Song; Huh, Nam-Su

    2013-01-01

    Highlights: • The lower bound bulging factor of thin-walled pipe can be used for thick-walled pipe. • The limit loads are proposed for thick-walled, transition through-wall cracked pipe. • The correction factors are proposed for estimating limit loads of transition cracks. • The limit loads of short transition cracks are similar to those of idealized cracks. - Abstract: The present paper provides plastic limit loads for non-idealized through-wall cracks in thick-walled pipe. These solutions are based on detailed 3-dimensional finite element (FE) analyses which can be used for structural integrity assessment of nuclear piping. To cover a practical range of interest, the geometric variables and loading conditions affecting the plastic limit loads of thick-walled pipe with non-idealized through-wall cracks were systematically varied. In terms of crack orientation, both circumferential and axial through-wall cracks were considered. As for loading conditions, axial tension, global bending, and internal pressure were considered for circumferential cracks, whereas only internal pressure was considered for axial cracks. Furthermore, the values of geometric factor representing shape characteristics of non-idealized through-wall cracks were also systematically varied. In order to provide confidence in the present FE analyses results, plastic limit loads of un-cracked, thick-walled pipe resulting from the present FE analyses were compared with the theoretical solutions. Finally, correction factors to the idealized through-wall crack solutions were developed to determine the plastic limit loads of non-idealized through-wall cracks in thick-walled pipe

  14. Calculations of secondary electron yield of graphene coated copper for vacuum electronic applications

    Directory of Open Access Journals (Sweden)

    H. K. A. Nguyen

    2018-01-01

    Full Text Available The suppression of secondary electron yield (SEY which can possibly lead to multipactor is an important goal for several applications. Though some techniques have focused on geometric modifications to lower the SEY, the use of graphene coatings as thin as a few monolayers is a promising new development that deserves attention either as a standalone technique or in concert with geometric alterations. Here we report on Monte Carlo based numerical studies of SEY on graphene coated copper with comparisons to recent experimental data. Our predicted values are generally in good agreement with reported measurements. Suppression of the secondary electron yield by as much as 50 percent (over copper with graphene coating is predicted at energies below 125 eV, and bodes well for multipactor suppression in radio frequency applications.

  15. A borehole stability study by newly designed laboratory tests on thick-walled hollow cylinders

    Directory of Open Access Journals (Sweden)

    S.S. Hashemi

    2015-10-01

    Full Text Available At several mineral exploration drilling sites in Australia, weakly consolidated formations mainly consist of sand particles that are poorly bonded by cementing agents such as clay, iron oxide cement or calcite. These formations are being encountered when drilling boreholes to the depth of up to 200 m. To study the behaviour of these materials, thick-walled hollow cylinder (TWHC and solid cylindrical synthetic specimens were designed and prepared by adding Portland cement and water to sand grains. The effects of different parameters such as water and cement contents, grain size distribution and mixture curing time on the characteristics of the samples were studied to identify the mixture closely resembling the formation at the drilling site. The Hoek triaxial cell was modified to allow the visual monitoring of grain debonding and borehole breakout processes during the laboratory tests. The results showed the significance of real-time visual monitoring in determining the initiation of the borehole breakout. The size-scale effect study on TWHC specimens revealed that with the increasing borehole size, the ductility of the specimen decreases, however, the axial and lateral stiffnesses of the TWHC specimen remain unchanged. Under different confining pressures the lateral strain at the initiation point of borehole breakout is considerably lower in a larger size borehole (20 mm compared to that in a smaller one (10 mm. Also, it was observed that the level of peak strength increment in TWHC specimens decreases with the increasing confining pressure.

  16. Reduction of the residual stresses in cold expanded thick-walled cylinders by plastic compression

    Directory of Open Access Journals (Sweden)

    V.F. Skvortsov

    2016-12-01

    Full Text Available We suppose that in order to maintain high accuracy of holes and to lower residual stresses after cold expansion of thick-walled cylinders, which undergo cross-section plastic deformation, it is necessary to perform axial plastic compression and subsequent cold expansion with small interferences. To test this hypothesis, we studied hoop, radial and axial residual stresses in cylinders made of carbon steel AISI 1050 with hole diameter of 5 mm, outer diameter of 15 mm and length of 30 mm by Sachs method as well as accuracy of expanded holes. It is found that double cold expansion with total interference equal to 5.1% generates hoop residual stresses with largest absolute value equal to 284 MPa and ensures high holes accuracy (IT7. After plastic compression with strain equal to 0.5 and 1% the mentioned stresses reduced to 120 and 75 MPa respectively, and accuracy of the holes reduced as well. Subsequent cold expansion with small interference equal to 0.9% helps to restore holes accuracy (IT7 gained by double cold expansion and ensure that absolute value of hoop residual stresses (177 MPa is lower compared to double cold expansion.

  17. Shear localization in 4340 steel with different microstructure using Thick Wall Cylinder method

    Science.gov (United States)

    Franco Navarro, Pedro; Chiu, Po-Hsun; Higgins, Andrew; Serge, Matthew; Benson, David; Nesterenko, Vitali

    2017-06-01

    Initiation and self-organization of shear bands in 4340 steel with initial low (2789 MPa) and high (5420 MPa) microhardnesses, but similar thermophysical properties, is studied using explosively driven Thick Wall Cylinder method and numerical simulations. In experiments low hardness 4340 steel demonstrated the initiation of a pattern of shear bands at global effective strain of about 0.53, which did not significantly change with increase of global strain up to 0.8. High microhardness 4340 steel demonstrated extremely different post-critical behavior. At global strain 0.56 a few well-developed shear bands propagated through the sample with their transformation into crack pattern at larger global strain 0.83. The propagation mechanism of shear bands in high hardness 4340 steel is explained by the interfacial microcracking between inclusions and matrix. Johnson-Cook material model with damage correctly predicted the dramatic change of shear bands pattern at similar global strains with change of initial properties of steel in numerical simulations. The pattern of shear bands was dependent on the number of initial material defects introduced by scaling of yield strength of mesh elements. P.F.N. wants to thank CONACYT-UCMEXUS for the funding.

  18. STATIONARY PROBLEM OF MOISTURE-INDUCED ELASTICITY OF HETEROGENEOUS THICK-WALLED CYLINDERS

    Directory of Open Access Journals (Sweden)

    Andreev Vladimir Igorevich

    2012-10-01

    Full Text Available Many problems of identification of the stress-strain state against the background of the heat and mass transfer are solved through the application of constant (averaged values of mechanical properties (elastic modulus, Poisson's ratio and derivation of differential equations with constant coefficients. Due to irregular distribution of temperature and other factors of impact, including the moisture content, mechanical properties of many materials change significantly; therefore, the problems in question are solved within the framework of mechanics of heterogeneous bodies. In this paper, the authors solve the classical problem of the steady-state moisture-induced elasticity of a thick-walled cylinder by taking account of the changes in the value of the elastic modulus caused by the influence of moisture. In this case, the problem is reduced to a differential equation with variable coefficients, which makes the solution more complicated though more accurate. It is proven that due regard for the heterogeneity leads to a significant increase in stresses, if compared to the solution based on the mean values of the modulus of elasticity.

  19. Identification and Quantification of Copper Sites in Zeolites by Electron Paramagnetic Resonance Spectroscopy

    DEFF Research Database (Denmark)

    Godiksen, Anita; Vennestrøm, Peter N. R.; Rasmussen, Søren Birk

    2017-01-01

    Recent quantitative electron paramagnetic resonance spectroscopy (EPR) data on different copper species present in copper exchanged CHA zeolites are presented and put into context with the literature on other copper zeolites. Results presented herein were obtained using ex situ and in situ EPR...... on copper ion exchanged into a CHA zeolite with Si/Al = 14 ± 1 to obtain Cu/Al = 0.46 ± 0.02. The results shed light on the identity of different copper species present after activation in air. Since the EPR signal is quantifiable, the content of the different EPR active species has been elucidated and Cu2......+ in 2Al positions in the 6-membered rings (6mr) of the CHA structure has been characterized. Some copper species are found not to give an EPR signal at ambient or high temperatures. Fortunately, treatments with different gasses under in situ conditions are able to trigger an EPR signal and thus reveal...

  20. The Influence of Air Exposures and Thermal Treatments on the Secondary Electron Yield of Copper

    CERN Document Server

    Bozhko, N; Scheuerlein, C

    2000-01-01

    The variation of the secondary electron yield (SEY) of sputter-cleaned OFHC-copper has been studied as a function of air exposure duration at room temperature. After short air exposures of some seconds the maximum SEY (deltaMAX) of clean copper is reduced from 1.3 to less than 1.2, due to the oxidation of the copper surface. Prolonged air exposure increases the SEY steadily until, after about 8 days of atmospheric exposure, deltaMAX is higher than 2.Air exposures at higher temperatures have been found to be effective in reducing the SEY of technical copper surfaces. A 5-minute air exposure of copper at 350°C followed by a 350°C bake-out under vacuum reduces deltaMAX to about 1.05, which is lower than the value of pure copper and that of Cu2O.

  1. Preferred sites and pathways for electron transfer in blue copper proteins

    DEFF Research Database (Denmark)

    Farver, O; Pecht, I

    1988-01-01

    of where and how electrons are transferred to and from the copper-ion have been investigated. One experimental approach developed in order to pursue these problems is that of reductively labeling several representative, yet structurally distinct blue single copper proteins; azurin, plastocyanin......, and stellacyanin with chromium ions. In all three cases, a substitution inert Cr(III)-adduct is formed when the oxidized protein is reduced by Cr(II)ag ions. In azurin, Cr(III) binds to the Glu-91 carboxylate approximately 10 A from the copper center. In both plastocyanin and stellacyanin the Cr(III) label is most...... probably also coordinated to carboxylate groups, present in plastocyanin, and in stellacyanin 12 A and 6 A, respectively, from the copper center. The salient feature emerging from examination of the three copper proteins is that a pi-facilitated electron transfer (E.T.) pathway may be operative; in azurin...

  2. The Influence of an Air Exposure on the Secondary Electron Yield of Copper

    CERN Document Server

    Scheuerlein, C

    1997-01-01

    The influence of different air exposure times on the secondary electron emission of clean copper surfaces as well as on technical copper surfaces has been studied in the context of the phenomenon of multipacting, which can limit the performance of superconducting radio-frequency (RF) cavities for particle acceleration. The copper samples were prepared by heat treatments and in situ sputter-etching and they were investigated with a instrument for SEY measurements, by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and by Auger electron spectroscopy (AES). After short air exposures of some seconds the maximum secondary electron yield dmax of clean copper is reduced from 1.3 to less than 1.2, due to the oxidation of the copper surface. Subsequent air exposure increases the secondary electron yield (SEY) until, after about 8 days exposure dmax is higher than 2. Clean copper samples were also exposed to the single gases present in air to find out the reasons for the dramatic increase of...

  3. Prevalence and histopathological finding of thin-walled and thick-walled Sarcocysts in slaughtered cattle of Karaj abattoir, Iran.

    Science.gov (United States)

    Nourollahi-Fard, Saeid R; Kheirandish, Reza; Sattari, Saeid

    2015-06-01

    Sarcocystosis is a zoonotic disease caused by Sarcocystis spp. with obligatory two host life cycle generally alternating between an herbivorous intermediate host and a carnivorous definitive host. Some species of this coccidian parasite can cause considerable morbidity and mortality in cattle. The present study was set to investigate the prevalence of Sarcocystis spp. and type of cyst wall in slaughtered cattle of Karaj abattoir, Iran. For this purpose 125 cattle (88 males and 37 females) were investigated for the presence of macroscopic and microscopic Sarcocystis cysts in muscular tissues. No macroscopic Sarcocystis cysts were found in any of the samples. In light microscopy, 121 out of 125 cattle (96.8 %) had thin-walled cysts of Sarcocystis cruzi, while 43 out of them (34.4 %) had thick-walled Sarcocystis cyst. In this survey, the most infected tissue was esophagus and heart and the less was diaphragm. Thin-walled cysts (S. cruzi) mostly found in heart and skeletal muscle showed the less. However, thick-walled cyst (S. hominis or S. hirsuta) mostly were detected in diaphragm, heart muscle showed no thick-walled cyst. No significant relation was observed between age and sex and the rate of infection. The results showed that Sarcocystis cyst is prevalent in cattle in the North part of Iran and the evaluation of infection potential can be useful when considering control programs.

  4. Selective Recovery Of Copper From Solutions After Bioleaching Electronic Waste

    Directory of Open Access Journals (Sweden)

    Willner Joanna

    2015-06-01

    Full Text Available Research on selective extraction of copper from solution after bioleaching grounded printed circuit boards (PCBs using LIX 860N-IC were conducted. The effect of LIX 860N-IC concentration, phase ratio and influence of initial pH value of aqueous phase on the extraction of copper and iron was examined. It was found that the extraction rate of copper increases with the LIX 860N-IC concentration. Best results of Cu extraction (98 % were achieved with extractant concentration of 5 % and pH 1.9. Higher pH value of aqueous phase (pH=2.4 is conducive to the simultaneous effect of Fe co-extraction.

  5. Investigation of the interaction of copper(II) oxide and electron beam irradiation crosslinkable polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Bee, Soo-Tueen, E-mail: direct.beest@gmail.com [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Sin, Lee Tin, E-mail: direct.tinsin@gmail.com [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Ratnam, C.T. [Radiation Processing Technology Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Haraveen, K.J.S.; Tee, Tiam-Ting [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Rahmat, A.R. [Department of Polymer Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2015-10-01

    In this study, the effects of electron beam irradiation on the properties of copper(II) oxide when added to low-density polyethylene (LDPE) blends were investigated. It was found that the addition of low loading level of copper(II) oxide (⩽2 phr) to LDPE results in significantly poorer gel content and hot set results. However, the incorporation of higher loading level of copper(II) oxide (⩾3 phr) could slightly increase the degree of crosslinking in all irradiated LDPE composites. This is due to the fact that higher amounts of copper(II) oxide could slightly induce the formation of free radicals in LDPE matrix. Besides, increasing irradiation doses was also found to gradually increase the gel content of LDPE composites by generating higher amounts of free radicals. As a consequence, these higher amounts of free radicals released in the LDPE matrix could significantly increase the degree of crosslinking. The addition of copper(II) oxide could reduce the tensile strength and fracture strain (elongation at break) of LDPE composites because of poorer interfacial adhesion effect between copper(II) oxide particles and LDPE matrix. Meanwhile, increasing irradiation doses on all copper(II) oxide added LDPE composites could marginally increase the tensile strength. In addition, increasing irradiation dose could enhance the thermal stability of LDPE composites by increasing the decomposition temperature. The oxidation induction time (OIT) analysis showed that, because of the crosslinking network in the copper(II) oxide added LDPE composites, oxidation reaction is much delayed.

  6. The Influence of Air Exposures and Thermal Treatments on the Secondary Electron Yield of Copper

    OpenAIRE

    Bozhko, N; Hilleret, Noël; Scheuerlein, C

    2000-01-01

    The variation of the secondary electron yield (SEY) of sputter-cleaned OFHC-copper has been studied as a function of air exposure duration at room temperature. After short air exposures of some seconds the maximum SEY (deltaMAX) of clean copper is reduced from 1.3 to less than 1.2, due to the oxidation of the copper surface. Prolonged air exposure increases the SEY steadily until, after about 8 days of atmospheric exposure, deltaMAX is higher than 2.Air exposures at higher temperatures have b...

  7. Influences of surfactants on the preparation of copper nanoparticles by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Ruimin [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China)], E-mail: zhourm47@staff.shu.edu.cn; Wu Xinfeng; Hao Xufeng; Zhou Fei [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China); Li Hongbin [Department of Chemical Engineering and Technology, Shanghai University, Shanghai 201800 (China); Rao Weihong [Shenzhen Tianding Fine Chemical Engineering Manufacturing Co., Ltd., Shenzhen, Guangdong 518057 (China)

    2008-02-15

    Electron beam radiation was applied to prepare nano-size copper in water system using polyvinyl alcohol, sodium dodecyl benzene sulfonate, gluten and polyethylene glycol as the surfactants, respectively. The irradiated products were characterized by XRD, TEM and LSPSDA. The XRD and TEM showed that relative pure copper products with an average size of 20 nm, 40 nm and 20 nm can be obtained by using gluten, PEG and SDBS as surfactant, respectively. An admixture of copper and cuprous oxide was obtained in PVA system. The LSPSDA showed that the size of the Cu nanoparticles decreased with increasing the glutin concentration.

  8. Electron Injection from Copper Diimine Sensitizers into TiO2

    DEFF Research Database (Denmark)

    Mara, Michael W.; Bowman, David N.; Buyukcakir, Onur

    2015-01-01

    Copper(I) diimine complexes have emerged as low cost replacements for ruthenium complexes as light sensitizers and electron donors, but their shorter metal-to-ligand-charge-transfer (MLCT) states lifetimes and lability of transient Cu(II) species impede their intended functions. Two carboxylated Cu...... on the efficiency of the interfacial electron-transfer process. The mechanisms for electron transfer in these systems are discussed and used to develop new strategies in optimizing copper(I) diimine complexes in solar energy conversion devices....

  9. Pseudoazurin from Sinorhizobium meliloti as an electron donor to copper-containing nitrite reductase: influence of the redox partner on the reduction potentials of the enzyme copper centers.

    Science.gov (United States)

    Ferroni, Félix M; Marangon, Jacopo; Neuman, Nicolás I; Cristaldi, Julio C; Brambilla, Silvina M; Guerrero, Sergio A; Rivas, María G; Rizzi, Alberto C; Brondino, Carlos D

    2014-08-01

    Pseudoazurin (Paz) is the physiological electron donor to copper-containing nitrite reductase (Nir), which catalyzes the reduction of NO2 (-) to NO. The Nir reaction mechanism involves the reduction of the type 1 (T1) copper electron transfer center by the external physiological electron donor, intramolecular electron transfer from the T1 copper center to the T2 copper center, and nitrite reduction at the type 2 (T2) copper catalytic center. We report the cloning, expression, and characterization of Paz from Sinorhizobium meliloti 2011 (SmPaz), the ability of SmPaz to act as an electron donor partner of S. meliloti 2011 Nir (SmNir), and the redox properties of the metal centers involved in the electron transfer chain. Gel filtration chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis together with UV-vis and EPR spectroscopies revealed that as-purified SmPaz is a mononuclear copper-containing protein that has a T1 copper site in a highly distorted tetrahedral geometry. The SmPaz/SmNir interaction investigated electrochemically showed that SmPaz serves as an efficient electron donor to SmNir. The formal reduction potentials of the T1 copper center in SmPaz and the T1 and T2 copper centers in SmNir, evaluated by cyclic voltammetry and by UV-vis- and EPR-mediated potentiometric titrations, are against an efficient Paz T1 center to Nir T1 center to Nir T2 center electron transfer. EPR experiments proved that as a result of the SmPaz/SmNir interaction in the presence of nitrite, the order of the reduction potentials of SmNir reversed, in line with T1 center to T2 center electron transfer being thermodynamically more favorable.

  10. Qualification of electron-beam welded joints between copper and stainless steel for cryogenic application

    OpenAIRE

    Lusch, C.; Borsch, M.; Heidt, C.; Magginetti, N.; Sas, J.; Weiss, K.-P.; Grohmann, Steffen

    2015-01-01

    Joints between copper and stainless steel are commonly applied in cryogenic systems. A relatively new and increasingly important method to combine these materials is electron-beam (EB) welding. Typically, welds in cryogenic applications need to withstand a temperature range from 300K down to 4 K, and pressures of several MPa. However, few data are available for classifying EB welds between OFHC copper and 316L stainless steel. A broad test program was conducted in order to qualify this kind o...

  11. Electronic properties and orbital-filling mechanism in Rb-intercalated copper phthalocyanine

    NARCIS (Netherlands)

    Evangelista, F.; Gotter, R.; Mahne, N.; Nannarone, S.; Ruocco, A.; Rudolf, P.

    2008-01-01

    The evolution of the electronic properties of a thin film of copper phthalocyanine deposited on Al(100) and progressively intercalated with rubidium atoms was followed by photoemission and X-ray absorption spectroscopies. Electron donation from the Rb atoms to the C32H16N8Cu molecules results in the

  12. rf breakdown measurements in electron beam driven 200 GHz copper and copper-silver accelerating structures

    Directory of Open Access Journals (Sweden)

    Massimo Dal Forno

    2016-11-01

    Full Text Available This paper explores the physics of vacuum rf breakdowns in subterahertz high-gradient traveling-wave accelerating structures. We present the experimental results of rf tests of 200 GHz metallic accelerating structures, made of copper and copper-silver. These experiments were carried out at the Facility for Advanced Accelerator Experimental Tests (FACET at the SLAC National Accelerator Laboratory. The rf fields were excited by the FACET ultrarelativistic electron beam. The traveling-wave structure is an open geometry, 10 cm long, composed of two halves separated by a gap. The rf frequency of the fundamental accelerating mode depends on the gap size and can be changed from 160 to 235 GHz. When the beam travels off axis, a deflecting field is induced in addition to the longitudinal field. We measure the deflecting forces by observing the displacement of the electron bunch and use this measurement to verify the expected accelerating gradient. Furthermore, we present the first quantitative measurement of rf breakdown rates in 200 GHz metallic accelerating structures. The breakdown rate of the copper structure is 10^{-2} per pulse, with a peak surface electric field of 500  MV/m and a rf pulse length of 0.3 ns, which at a relatively large gap of 1.5 mm, or one wavelength, corresponds to an accelerating gradient of 56  MV/m. For the same breakdown rate, the copper-silver structure has a peak electric field of 320  MV/m at a pulse length of 0.5 ns. For a gap of 1.1 mm, or 0.74 wavelengths, this corresponds to an accelerating gradient of 50  MV/m.

  13. Analysis of the Causes of Cracks in a Thick-Walled Bush Made of Die-Cast Aluminum Bronze

    Directory of Open Access Journals (Sweden)

    Pisarek B.P.

    2016-12-01

    Full Text Available For the die casting conditions of aluminium bronzes assumed based on the literature data, a thick-walled bush was cast, made of complex aluminium bronze (Cu-Al-Fe-Ni-Cr. After the cast was removed from the mould, cracks were observed inside it. In order to identify the stage in the technological production process at which, potentially, the formation of stresses damaging the continuity of the microstructure created in the cast was possible (hot cracking and/or cold cracking, a computer simulation was performed. The article presents the results of the computer simulation of the process of casting the material into the gravity die as well as solidifying and cooling of the cast in the shape of a thick-walled bush. The simulation was performed with the use of the MAGMA5 program and by application of the CuAl10Ni5,5Fe4,5 alloy from the MAGMA5 program database. The results were compared with the location of the defects identified in the actual cast. As a result of the simulation of the die-casting process of this bush, potential regions were identified where significant principal stresses accumulate, which can cause local hot and cold cracking. Until now, no research has been made of die-cast aluminium bronzes with a Cr addition. Correlating the results of the computer simulation validated by the analysis of the actual cast made it possible to clearly determine the critical regions in the cast exposed to cracking and point to the causes of its occurrence. Proposals of changes in the bush die casting process were elaborated, in order to avoid hot tearing and cold cracking. The article discusses the results of preliminary tests being a prologue to the optimization of the die-casting process parameters of complex aluminium bronze thick-walled bushs.

  14. Copper leaching from electronic waste for the improvement of gold recycling.

    Science.gov (United States)

    Torres, Robinson; Lapidus, Gretchen T

    2016-11-01

    Gold recovery from electronic waste material with high copper content was investigated at ambient conditions. A chemical preliminary treatment was found necessary to remove the large quantities of copper before the precious metal can be extracted. For this purpose inorganic acids (HCl, HNO 3 and H 2 SO 4 ) and two organic substances EDTA and citrate, were tested. The effect of auxiliary oxidants such as air, ozone and peroxide hydroxide was studied. In pretreatments with peroxide and HCl or citrate, copper extractions greater than 90% were achieved. In the second leaching stage for gold recovery, the solid residue of the copper extraction was contacted with thiourea solutions, resulting in greater than 90% gold removal after only one hour of reaction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Study on the Thick-Walled Pipe Ultrasonic Signal Enhancement of Modified S-Transform and Singular Value Decomposition

    Directory of Open Access Journals (Sweden)

    Haichao Cai

    2015-01-01

    Full Text Available When detecting the ultrasonic flaw of thick-walled pipe, the flaw echo signals are often interrupted by scanning system frequency and background noise. In particular when the thick-walled pipe defect is small, echo signal amplitude is often drowned in noise signal and affects the extraction of defect signal and the position determination accuracy. This paper presents the modified S-transform domain singular value decomposition method for the analysis of ultrasonic flaw echo signals. By changing the scale rule of Gaussian window functions with S-transform to improve the time-frequency resolution. And the paper tries to decompose the singular value decomposition of time-frequency matrix after the S-transform to determine the singular entropy of effective echo signal and realize the adaptive filter. Experiments show that, using this method can not only remove high frequency noise but also remove the low frequency noise and improve the signal-to-noise ratio of echo signal.

  16. Electronic Structural Analysis of Copper(II)-TEMPO/ABNO Complexes Provides Evidence for Copper(I)-Oxoammonium Character.

    Science.gov (United States)

    Walroth, Richard C; Miles, Kelsey C; Lukens, James T; MacMillan, Samantha N; Stahl, Shannon S; Lancaster, Kyle M

    2017-09-27

    Copper/aminoxyl species are proposed as key intermediates in aerobic alcohol oxidation. Several possible electronic structural descriptions of these species are possible, and the present study probes this issue by examining four crystallographically characterized Cu/aminoxyl halide complexes by Cu K-edge, Cu L 2,3 -edge, and Cl K-edge X-ray absorption spectroscopy. The mixing coefficients between Cu, aminoxyl, and halide orbitals are determined via these techniques with support from density functional theory. The emergent electronic structure picture reveals that Cu coordination confers appreciable oxoammonium character to the aminoxyl ligand. The computational methodology is extended to one of the putative intermediates invoked in catalytic Cu/aminoxyl-driven alcohol oxidation reactions, with similar findings. Collectively, the results have important implications for the mechanism of alcohol oxidation and the underlying basis for cooperativity in this co-catalyst system.

  17. Ion induced high energy electron emission from copper

    International Nuclear Information System (INIS)

    Ruano, G.; Ferron, J.

    2008-01-01

    We present measurements of secondary electron emission from Cu induced by low energy bombardment (1-5 keV) of noble gas (He + , Ne + and Ar + ) and Li + ions. We identify different potential and kinetic mechanisms and find the presence of high energetic secondary electrons for a couple of ion-target combinations. In order to understand the presence of these fast electrons we need to consider the Fermi shuttle mechanism and the different ion neutralization efficiencies.

  18. Study of thermal stability of ultrafine-grained copper by means of electron back scattering diffraction

    Czech Academy of Sciences Publication Activity Database

    Man, O.; Pantělejev, L.; Kunz, Ludvík

    2010-01-01

    Roč. 51, č. 2 (2010), s. 209-213 ISSN 1345-9678 R&D Projects: GA AV ČR 1QS200410502 Institutional research plan: CEZ:AV0Z20410507 Keywords : ultra-fine grained copper * thermal stability of microstructure * electron back scattering diffraction * grain size * texture Subject RIV: JG - Metallurgy Impact factor: 0.779, year: 2010

  19. Electronic structure of copper phthalocyanine : An experimental and theoretical study of occupied and unoccupied levels

    NARCIS (Netherlands)

    Evangelista, Fabrizio; Carravetta, Vincenzo; Stefani, Giovanni; Jansik, Branislav; Alagia, Michele; Stranges, Stefano; Ruocco, Alessandro

    2007-01-01

    An experimental and theoretical study of the electronic structure of copper phthalocyanine (CuPc) molecule is presented. We performed x-ray photoemission spectroscopy (XPS) and photoabsorption [x-ray absorption near-edge structure (XANES)] gas phase experiments and we compared the results with

  20. Transient Response of a Fluid-Filled, Thick-Walled Spherical Shell Embedded in an Elastic Medium

    Directory of Open Access Journals (Sweden)

    Bahari Ako

    2016-01-01

    Full Text Available The paper addresses the problem of transient elastodynamics analysis of a thick-walled, fluid-filled spherical shell embedded in an elastic medium with an analytical approach. This configuration is investigated at first step for a full-space case. Different constitutive relations for the elastic medium, shell material and filling fluid can be considered, as well as different excitation sources (including S/P wave or plane/spherical incident wave at different locations. With mapmaking visualisation, the wave propagation phenomena can be described and better understood. The methodology is going to be applied to analysis of the tunnels or other shell like structures under the effect of nearby underground explosion.

  1. Preferred sites and pathways for electron transfer in blue copper proteins

    DEFF Research Database (Denmark)

    Farver, O; Pecht, I

    1988-01-01

    probably also coordinated to carboxylate groups, present in plastocyanin, and in stellacyanin 12 A and 6 A, respectively, from the copper center. The salient feature emerging from examination of the three copper proteins is that a pi-facilitated electron transfer (E.T.) pathway may be operative; in azurin......, E.T. proceeds via an extended imidazole ring system, and in plastocyanin and stellacyanin via a weakly coupled pi-system. Therefore, a case emerges for suggesting that this is the common feature of the long-distance intramolecular E.T. in this class of metalloproteins. These pathways are most...... probably a regulatory alternative to the E.T. site recognized at the exposed, "Northern" imidazole coordinated to copper in all these proteins....

  2. Anomalous electronic heat capacity of copper nanowires at sub-Kelvin temperatures

    Science.gov (United States)

    Viisanen, K. L.; Pekola, J. P.

    2018-03-01

    We have measured the electronic heat capacity of thin film nanowires of copper and silver at temperatures 0.1-0.3 K; the films were deposited by standard electron-beam evaporation. The specific heat of the Ag films of sub-100-nm thickness agrees with the bulk value and the free-electron estimate, whereas that of similar Cu films exceeds the corresponding reference values by one order of magnitude. The origin of the anomalously high heat capacity of copper films remains unknown for the moment. Based on the small heat capacity at low temperatures and the possibility to devise a tunnel probe thermometer on it, metal films form a promising absorber material, e.g., for microwave photon calorimetry.

  3. Radiography of welded joints of thick-walled equipment using a mobile linear accelerator

    International Nuclear Information System (INIS)

    Vanek, J.; Krejci, M.

    1988-01-01

    The different aspects are discussed of the choice of a suitable source for nondestructive testing of materials of great thickness. The ORION mobile linear accelerator by the French company CGR MeV with 4 MeV electron energy was selected for the nondestructive testing of 200 mm thick welded joints. The principles and methods of health protection at work with this device are described as is the optimization of the economic efficiency of its use. Great attention was focused on the quality of the resulting image and the choice of intensifying foils. The one year operating experience with the accelerator is evaluated. (M.D.). 4 figs., 1 tab., 8 refs

  4. Deep level centers in electron-irradiated silicon crystals doped with copper at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Yarykin, Nikolai [Institute of Microelectronics Technology, RAS, Chernogolovka (Russian Federation); Weber, Joerg [Technische Universitaet Dresden (Germany)

    2017-07-15

    The effect of bombardment with energetic particles on the deep-level spectrum of copper-contaminated silicon wafers is studied by space charge spectroscopy methods. The p-type FZ-Si wafers were doped with copper in the temperature range of 645-750 C and then irradiated with the 10{sup 15} cm{sup -2} fluence of 5 MeV electrons at room temperature. Only the mobile Cu{sub i} species and the Cu{sub PL} centers are detected in significant concentrations in the non-irradiated Cu-doped wafers. The properties of the irradiated samples are found to qualitatively depend on the copper in-diffusion temperature T{sub diff}. For T{sub diff} > 700 C, the irradiation partially reduces the Cu{sub i} concentration and introduces additional Cu{sub PL} centers while no standard radiation defects are detected. If T{sub diff} was below ∝700 C, the irradiation totally removes the mobile Cu{sub i} species. Instead, the standard radiation defects and their complexes with copper appear in the deep-level spectrum. A model for the defects reaction scheme during the irradiation is derived and discussed. DLTS spectrum of the Cu-contaminated and then irradiated silicon qualitatively depends on the copper in-diffusion temperature. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. The intramolecular electron transfer between copper sites of nitrite reductase

    DEFF Research Database (Denmark)

    Farver, O; Eady, R R; Abraham, Z H

    1998-01-01

    The intramolecular electron transfer (ET) between the type 1 Cu(I) and the type 2 Cu(II) sites of Alcaligenes xylosoxidans dissimilatory nitrite reductase (AxNiR) has been studied in order to compare it with the analogous process taking place in ascorbate oxidase (AO). This internal process is in...

  6. Determination of the threshold of nanoparticle behavior: Structural and electronic properties study of nano-sized copper

    International Nuclear Information System (INIS)

    Torres-Vega, Juan J.; Medrano, L.R.; Landauro, C.V.; Rojas-Tapia, J.

    2014-01-01

    In the present work we determine the threshold of the nanoparticle behavior of copper nanoparticles by studying their structural and electronic properties. The studied nanoparticles contain from 13 to 8217 atoms and were obtained by molecular dynamics simulations using the Johnson potential for copper based on the embedded atom method. The results indicate that for small copper nanoparticles ( 2000atoms, ∼3.5 nm), with spherical-like external shape and large percentage of fcc-like local structure, this effect is negligible and their electronic character are similar to such expected in solid copper. Finally, it has also been shown that copper nanoparticles change their electronic character, from metallic to insulating, after increasing the strength of the chemical disorder

  7. Lifetime assessment of thick-walled components made of nickel-base alloys under near-service loading conditions

    International Nuclear Information System (INIS)

    Hueggenberg, Daniel

    2015-01-01

    and the transmission electron microscope for the base raw material, the creep and creep-fatigue exposed material. For the classification the investigation results were compared to the results of the other projects and no differences could be identified. For the description of the deformation and damage behavior under creep-fatigue loading with finite elements simulations a viscoplastic deformation model with an integrated damage model of Lemaitre was used. The material dependent model parameters were fitted under consideration of the basis characterization test results of the Alloy 617 mod. and Alloy 263. All basis characterization tests are simulated with finite elements to classify the parameter fittings. The verification of the fitted material models was carried out by simulations of the complex lab tests. From the comparison of the simulation and test results it is obvious that the deformation and damage behavior can be reproduced with the used material model in a good manner. With finite element simulations of complex thick-walled components (header, formed part) under realistic thermal and mechanic loading conditions could be shown that the viscoplastic material model fitted for the Alloy 617 mod. and Alloy 263 is able to predict the locations of the maximum loadings and the lifetime until the first cracks appear. This could be confirmed by dye penetrant testing on the one hand and destructive investigations of two fracture surfaces of the header on the other hand. Additionally the approaches of the European DIN EN 12952-3/4, the American ASME Section III Division 1 Subsection NH, the French RCC-MR RB 3262.12 and the British R5 recommendations Volume 2/3 are used to predict the lifetimes. It can be seen that the approaches of ASME and RCC-MR provide very conservative predictions and that the approaches of R5 and DIN EN 12952 provide non-conservative predictions. These results lead to the conclusion that no approach of the standards/recommendation is suitable for

  8. Revealing the Formation of Copper Nanoparticles from a Homogeneous Solid Precursor by Electron Microscopy

    DEFF Research Database (Denmark)

    van den Berg, Roy; Elkjær, Christian Fink; Gommes, Cedric J.

    2016-01-01

    nucleation. The combination of a uniform size of precursor particles and the autocatalytic reduction thus offers means to synthesize nanoparticles with well-defined sizes in large amounts. In this way, in situ observations made by electron microscopy provide mechanistic and kinetic insights......The understanding of processes leading to the formation of nanometer-sized particles is important for tailoring of their size, shape and location. The growth mechanisms and kinetics of nanoparticles from solid precursors are, however, often poorly described. Here we employ transmission electron...... microscopy (TEM) to examine the formation of copper nanoparticles on a silica support during the reduction by H2 of homogeneous copper phyllosilicate platelets, as a prototype precursor for a coprecipitated catalyst. Specifically, time-lapsed TEM image series acquired of the material during the reduction...

  9. Subthreshold displacement damage in copper--aluminum alloys during electron irradiation

    International Nuclear Information System (INIS)

    Drosd, R.; Kosel, T.; Washburn, J.

    1976-12-01

    During electron irradiation at low energies which results in a negligible damage rate in a pure material, lighter solute atoms are displaced, which may in turn indirectly displace solvent atoms by a focussed replacement collision or an interstitial diffusion jump. The extent to which lighter solute atoms contribute to the subthreshold damage rate has been examined by irradiating copper--aluminum alloys at high temperatures in a high voltage electron microscope. The damage rate, as measured by monitoring the growth rate of dislocation loops, at 300 kV was found to increase linearly with the aluminum concentration

  10. Development of a Flexible Broadband Rayleigh Waves Comb Transducer with Nonequidistant Comb Interval for Defect Detection of Thick-Walled Pipelines

    Science.gov (United States)

    He, Cunfu; Yan, Lyu; Zhang, Haijun

    2018-01-01

    It is necessary to develop a transducer that can quickly detect the inner and outer wall defects of thick-walled pipes, in order to ensure the safety of such pipes. In this paper, a flexible broadband Rayleigh-waves comb transducer based on PZT (lead zirconate titanate) for defect detection of thick-walled pipes is studied. The multiple resonant coupling theory is used to expand the transducer broadband and the FEA (Finite Element Analysis) method is used to optimize transducer array element parameters. Optimization results show that the best array element parameters of the transducer are when the transducer array element length is 30 mm, the thickness is 1.2 mm, the width of one end of is 1.5 mm, and the other end is 3 mm. Based on the optimization results, such a transducer was fabricated and its performance was tested. The test results were consistent with the finite-element simulation results, and the −3 dB bandwidth of the transducer reached 417 kHz. Transducer directivity test results show that the Θ−3dB beam width was equal to 10 °, to meet the defect detection requirements. Finally, defects of thick-walled pipes were detected using the transducer. The results showed that the transducer could detect the inner and outer wall defects of thick-walled pipes within the bandwidth. PMID:29498636

  11. Numerical investigation on residual stress distribution and evolution during multipass narrow gap welding of thick-walled stainless steel pipes

    International Nuclear Information System (INIS)

    Liu, C.; Zhang, J.X.; Xue, C.B.

    2011-01-01

    Research highlights: → We performed pass-by-pass simulation of stresses for welding of thick-walled pipes. → The distributions and evolution of the residual stresses are demonstrated. → After the groove is filled to a height, the through-wall stress is almost unchanged. - Abstracts: The detailed pass-by-pass finite element (FE) simulation is presented to investigate the residual stresses in narrow gap multipass welding of pipes with a wall thickness of 70 mm and 73 weld passes. The simulated residual stress on the outer surface is validated with the experimental one. The distribution and evolution of the through-wall residual stresses are demonstrated. The investigated results show that the residual stresses on the outer and inner surfaces are tensile in the weld zone and its vicinity. The through-wall axial residual stresses at the weld center line and the HAZ line demonstrate a distribution of bending type. The through-wall hoop residual stress within the weld is mostly tensile. After the groove is filled to a certain height, the peak tensile stresses and the stress distribution patterns for both axial and hoop stresses remain almost unchanged.

  12. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Modification of graphene electronic properties via controllable gas-phase doping with copper chloride

    Science.gov (United States)

    Rybin, Maxim G.; Islamova, Vera R.; Obraztsova, Ekaterina A.; Obraztsova, Elena D.

    2018-01-01

    Molecular doping is an efficient, non-destructive, and simple method for changing the electronic structure of materials. Here, we present a simple air ambient vapor deposition method for functionalization of pristine graphene with a strong electron acceptor: copper chloride. The doped graphene was characterized by Raman spectroscopy, UV-vis-NIR optical absorption spectroscopy, scanning electron microscopy, and electro-physical measurements performed using the 4-probe method. The effect of charge transfer from graphene to a dopant results in shifting the Fermi level in doped graphene. The change of the electronic structure of doped graphene was confirmed by the tangential Raman peak (G-peak) shift and by the appearance of the gap in the UV-vis-NIR spectrum after doping. Moreover, the charge transfer resulted in a substantial decrease in electrical sheet resistance depending on the doping level. At the highest concentration of copper chloride, a Fermi level shift into the valence band up to 0.64 eV and a decrease in the sheet resistance value by 2.36 times were observed (from 888 Ω/sq to 376 Ω/sq for a single graphene layer with 97% of transparency).

  14. Feasibility study of electron beam welding of spent nuclear fuel canisters

    International Nuclear Information System (INIS)

    Sanderson, A.; Szluha, T.F.; Turner, J.L.; Leggatt, R.H.

    1983-04-01

    A thick walled copper container is presently the prime Swedish alternative for encapsulation of spent nuclear fuel. In order to demonstrate the feasibility of encapsulating high-level nuclear waste in copper containers, a study of electron beam welding of thick copper has been performed. Two copper qualities have been investigated, oxygen free high conductivity (OFHC) copper and phosphorous desoxydized high conductivity copper (PDO). The findings in this study are summarized below. In 100 mm thick copper penetration can be achived at power level of about 75 kW (typically 150 kV x 500 mA) at welding speed of 100 mm/min. The welds in OFHC copper made under these conditions are free from major defects during constant welding conditions. The welds in PDO copper show a microporosity level considerably higher than those in OFHC copper, but no major defects are produced in the welds in PDO copper. In the ending of the weld (ie the fade out) it is still not possible to completely eliminate root and cold-shut defects. A semi-full-scale lid weld has been performed successfully. Automatic ultrasonic C-scan has been shown to be useful in detecting and displaying defects, but some problems still remain with defect sizing. The different speciments of OFHS copper had different attenuation of the ultrasonic signal, forged copper showing a far lower attenuation than hot extruded copper, indicating that attention must be paid in choosing copper that allows accurate ultrasonic testing. Resiudal stresses in the welded zone has been measured and are found to lie in the range -32N/mm 2 to +36N/mm 2 . The peak stress was less than half the assumed value of the proof stress of the fused metal. (authors)

  15. Qualification of electron-beam welded joints between copper and stainless steel for cryogenic application

    Science.gov (United States)

    Lusch, C.; Borsch, M.; Heidt, C.; Magginetti, N.; Sas, J.; Weiss, K.-P.; Grohmann, S.

    2015-12-01

    Joints between copper and stainless steel are commonly applied in cryogenic systems. A relatively new and increasingly important method to combine these materials is electron-beam (EB) welding. Typically, welds in cryogenic applications need to withstand a temperature range from 300K down to 4K, and pressures of several MPa. However, few data are available for classifying EB welds between OFHC copper and 316L stainless steel. A broad test program was conducted in order to qualify this kind of weld. The experiments started with the measurement of the hardness in the weld area. To verify the leak-tightness of the joints, integral helium leak tests at operating pressures of 16 MPa were carried out at room- and at liquid nitrogen temperature. The tests were followed by destructive tensile tests at room temperature, at liquid nitrogen and at liquid helium temperatures, yielding information on the yield strength and the ultimate tensile strength of the welds at these temperatures. Moreover, nondestructive tensile tests up to the yield strength, i.e. the range in which the weld can be stressed during operation, were performed. Also, the behavior of the weld upon temperature fluctuations between room- and liquid nitrogen temperature was tested. The results of the qualification indicate that EB welded joints between OFHC copper and 316L stainless steel are reliable and present an interesting alternative to other technologies such as vacuum brazing or friction welding.

  16. Low frequency internal friction behaviour of copper after electron-irradiation at 20 K

    International Nuclear Information System (INIS)

    Sokolowski, G.; Kabsch, Z.; Moser, P.

    1978-01-01

    High-purity ASARCO-copper has been irradiated with 3MeV-electrons at 20 K. Then the temperature dependence of modulus and decrement has been measured at 2 Hz and a strain amplitude of 10 -5 . The dislocation pinning in stage I can be seen in modulus and decrement. It is followed by a depinning process in the modulus between 130 and 190 K. This depinning corresponds to the temperature where the decrement begins to increase again after stage I-pinning. The effects are discussed and compared to 78K irradiations using the same sample material and similar pre-treatment

  17. Positron annihilation and electron microscopy study in the early stage of fatigue of polycrystalline copper

    International Nuclear Information System (INIS)

    Diaz, L.; Pareja, R.; Pedrosa, M.A.; Gonzalez, R.

    1985-01-01

    Positron annihilation and transmission electron microscopy are used to study the early stage of fatigue in polycrystalline copper cyclically deformed at various temperatures. The concentration of positron traps is correlated to the cumulative plastic strain and to the work done during deformation. The average lifetimes of the trapped positrons are (177 +- 4) and (186 +- 3) ps for samples fatigued at T 15 s -1 for the samples deformed at T <= 293 K. Vacancy clusters like small dislocation loops, are proposed as the main defects responsible for the positron trapping. (author)

  18. Interpretation of the Electron Paramagnetic Resonance Spectra of Copper(II)-Tyrosine Complex

    Science.gov (United States)

    Xu, Xiao-Hui; Kuang, Min-Quan

    2017-12-01

    The electron paramagnetic resonance (EPR) spectra of [Cu(l-tyrosine)2]n (CuA) were interpreted based on the fourth-order perturbation treatments where the contributions due to the local distortion, ligand orbit and spin-orbit coupling were included. The calculated band transitions d_{x^2} - y^2 to dxy (≈16412 cm-1) and d_{z^2} (≈14845 cm-1) agree well with the band analysis results (d_{x^2} - y^2 \\to d_{xy} ≈16410 and d_{x^2} - y^2 \\to d_{z^2} ≈14850 cm-1). The unresolved separations d_{x^2} - y^2 \\to d_{xz} and d_{x^2} - y^2 \\to d_{yz} in the absorption spectra were evaluated as 26283 and 26262 cm-1, respectively. For CuA, copper chromophores in 1,3-diaminorpropane isophtalate copper(II) complex (CuB) and N-methyl-1,2-diaminoetaane-bis copper(II) polymer (CuC), the transition d_{x^2} - y^2 \\to d_{xy} (=E1≈10Dq) suffered an increase with a decrease in R̅L which was evaluated as the mean value of the copper-ligand bond lengths. The correlations between the tetragonal elongation ratio ρ (=(Rz-R̅L)/R̅L) (or the ratio G=(gz-ge)/((gx+gy)/2-ge)) and the g isotropy gav (=(gx+gy+gz)/3) (or the covalency factor N) for CuA, CuB and CuC were acquired and all the results were discussed.

  19. Extreme regimes of femtosecond photoemission from a copper cathode in a dc electron gun

    Directory of Open Access Journals (Sweden)

    P. L. E. M. Pasmans

    2016-10-01

    Full Text Available The femtosecond photoemission yield from a copper cathode and the emittance of the created electron beams has been studied in a 12  MeV/m, 100 keV dc electron gun over a wide range of laser fluence, from the linear photoemission regime until the onset of image charge limitations and cathode damaging. The measured photoemission curves can be described well with available theory which includes the Schottky effect, second-order photoemission, and image charge limitation. The second-order photoemission can be explained by thermally assisted one-photon photoemission (1PPE and by above-threshold two-photon photoemission (2PPE. Measurements with a fresh cathode suggest that the 2PPE process is dominant. The beam emittance has been measured for the entire range of initial surface charge densities as well. The emittance measurements of space-charge dominated beams can be described well by an envelope equation with generalized perveance. The dc gun produces 0.1 pC bunches with 25 nm rms normalized emittance, corresponding to a normalized brightness usually associated with rf photoguns. In this experimental study the limits of femtosecond photoemission from a copper cathode have been explored and analyzed in great detail, resulting in improved understanding of the underlying mechanisms.

  20. Microstructural evolution in adiabatic shear bands of copper at high strain rates: Electron backscatter diffraction characterization

    International Nuclear Information System (INIS)

    Tang Lin; Chen Zhiyong; Zhan Congkun; Yang Xuyue; Liu Chuming; Cai Hongnian

    2012-01-01

    The microstructural evolution of adiabatic shear bands in annealed copper with different large strains at high strain rates has been investigated by electron backscatter diffraction. The results show that mechanical twinning can occur with minimal contribution to shear localization under dynamic loading. Elongated ultrafine grains with widths of 100–300 nm are observed during the evolution of the adiabatic shear bands. A rotational dynamic recrystallization mechanism is proposed to explain the formation of the elongated ultrafine grains. - Highlights: ► The microstructural evolution of ASB is studied by electron backscatter diffraction. ► Twinning can occur in ASB while the contribution to shear localization is slight. ► Elongated ultrafine grains are observed during the evolution process of ASB. ► A possible mechanism is proposed to explain the microstructure evolution of ASB.

  1. Distribution of Energy Deposited in Plastic Tubing and Copper-Wire Insulation by Electron Beam Irradiation

    DEFF Research Database (Denmark)

    Pedersen, Walther Batsberg; Miller, Arne; Pejtersen, K.

    1978-01-01

    Scanned electron beam treatment is used to improve the physical properties of certain polymers, such as shrinkable plastic tubing and insulated wire and cable. Tubing or wires are passed at high speed under the beam scanner, and the material is irradiated to absorbed doses of several Mrad...... as uniformly as possible, usually by means of a multipass arrangement. In the present study, using irradiation by a scanned 0.4 MeV electron beam, measurements were made of high-resolution distributions of absorbed dose in polyethylene tubing and copper wire coated with polyethylene, nylon, or polyvinyl...... chloride insulation. Radiochromic dye films equivalent to the insulating materials were used as accurate dosimeters having a response independent of dose rate. Irradiations were in various geometries, wire and plastic thicknesses, positions along the beam scan, and with different backing materials near...

  2. A tale of two neglected systems—structure and function of the thin- and thick-walled sieve tubes in monocotyledonous leaves

    Science.gov (United States)

    Botha, C. E. J.

    2013-01-01

    There is a large body of information relating to the ontogeny, development and the vasculature of eudicotyledonous leaves. However, there is less information available concerning the vascular anatomy of monocotyledonous leaves. This is surprising, given that there are two uniquely different phloem systems present in large groups such as grasses and sedges. Monocotyledonous leaves contain marginal, large, intermediate, and small longitudinal veins that are interconnected by numerous transverse veins. The longitudinal veins contain two metaphloem sieve tube types, which, based upon their ontogeny and position within the phloem, are termed early (thin-walled) and late (thick-walled) sieve tubes. Early metaphloem comprises sieve tubes, companion cells and vascular parenchyma (VP) cells, whilst the late metaphloem, contains thick-walled sieve tubes (TSTs) that lack companion cells. TSTs are generally adjacent to, or no more than one cell removed from the metaxylem. Unlike thin-walled sieve tube (ST) -companion cell complexes, TSTs are connected to parenchyma by pore-plasmodesma units and are generally symplasmically isolated from the STs. This paper addresses key structural and functional differences between thin- and thick-walled sieve tubes and explores the unique advantages of alternate transport strategies that this 5–7 million years old dual system may offer. It would seem that these two systems may enhance, add to, or play a significant role in increasing the efficiency of solute retrieval as well as of assimilate transfer. PMID:23964280

  3. A tale of two neglected systems-structure and function of the thin- and thick-walled sieve tubes in monocotyledonous leaves.

    Science.gov (United States)

    Botha, C E J

    2013-01-01

    There is a large body of information relating to the ontogeny, development and the vasculature of eudicotyledonous leaves. However, there is less information available concerning the vascular anatomy of monocotyledonous leaves. This is surprising, given that there are two uniquely different phloem systems present in large groups such as grasses and sedges. Monocotyledonous leaves contain marginal, large, intermediate, and small longitudinal veins that are interconnected by numerous transverse veins. The longitudinal veins contain two metaphloem sieve tube types, which, based upon their ontogeny and position within the phloem, are termed early (thin-walled) and late (thick-walled) sieve tubes. Early metaphloem comprises sieve tubes, companion cells and vascular parenchyma (VP) cells, whilst the late metaphloem, contains thick-walled sieve tubes (TSTs) that lack companion cells. TSTs are generally adjacent to, or no more than one cell removed from the metaxylem. Unlike thin-walled sieve tube (ST) -companion cell complexes, TSTs are connected to parenchyma by pore-plasmodesma units and are generally symplasmically isolated from the STs. This paper addresses key structural and functional differences between thin- and thick-walled sieve tubes and explores the unique advantages of alternate transport strategies that this 5-7 million years old dual system may offer. It would seem that these two systems may enhance, add to, or play a significant role in increasing the efficiency of solute retrieval as well as of assimilate transfer.

  4. Fluorescent copper(II complexes: The electron transfer mechanism, interaction with bovine serum albumin (BSA and antibacterial activity

    Directory of Open Access Journals (Sweden)

    Madhumita Hazra

    2017-01-01

    Full Text Available Dinuclear copper(II complexes with formula [Cu2(L2(N32] (1 and [Cu2(L2(NCS2] (2 HL = (1-[(3-methyl-pyridine-2-ylimino-methyl]-naphthalen-2-ol were synthesized by controlling the molar ratio of Cu(OAC2·6H2O, HL, sodium azide (1 and ammonium thiocyanate (2. The end on bridges appear exclusively in azide and thiocyanate to copper complexes. The electron transfer mechanism of copper(II complexes is examined by cyclic voltammetry indicating copper(II complexes are Cu(II/Cu(I couple. The interactions of copper(II complexes towards bovine serum albumin (BSA were examined with the help of absorption and fluorescence spectroscopic tools. We report a superficial solution-based route for the synthesis of micro crystals of copper complexes with BSA. The antibacterial activity of the Schiff base and its copper complexes were investigated by the agar disc diffusion method against some species of pathogenic bacteria (Escherichia coli, Vibrio cholerae, Streptococcus pneumonia and Bacillus cereus. It has been observed that the antibacterial activity of all complexes is higher than the ligand.

  5. Influence of surface topography on the secondary electron yield of clean copper samples.

    Science.gov (United States)

    Hu, Xiao-Chuan; Cao, Meng; Cui, Wan-Zhao

    2016-11-01

    Secondary electron yield (SEY) due to electron impact depends strongly on surface topography. The SEY of copper samples after Ar-ion bombardment is measured in situ in a multifunctional ultrahigh vacuum system. Increasing the ion energy or duration of ion bombardment can even enlarge the SEY, though it is relatively low under moderate bombardment intensity. The results obtained with scanning electron microscopy and atomic force microscopy images demonstrate that many valley structures of original sample surfaces can be smoothed due to ion bombardment, but more hill structures are generated with stronger bombardment intensity. With increasing the surface roughness in the observed range, the maximum SEY decreases from 1.2 to 1.07 at a surface characterized by valleys, while it again increases to 1.33 at a surface spread with hills. This phenomenon indicates that hill and valley structures are respectively effective in increasing and decreasing the SEY. These obtained results thus provide a comprehensive insight into the surface topography influence on the secondary electron emission characteristics in scanning electron microscopy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Synchrotron-based measurements of the electronic structure of the organic semiconductor copper phthalocyanine

    International Nuclear Information System (INIS)

    Downes, J.E.

    2004-01-01

    Full text: Copper phthalocyanine (CuPc) is a prototypical molecular organic semiconductor that is currently used in the construction of many organic electronic devices such as organic light emitting diodes (OLEDs). Although the material is currently being used, and despite many experimental and theoretical studies, it's detailed electronic structure is still not completely understood. This is likely due to two key factors. Firstly, the interaction of the Cu 3d and phthalocyanine ligand 2p electrons leads to the formation of a complex arrangement of localized and delocalized states near the Fermi level. Secondly, thin films of the material are subject to damage by the photon beam used to make measurements of their electronic structure. Using the synchrotron-based techniques of soft x-ray emission spectroscopy (XES) and x-ray photoemission spectroscopy (XPS), we have measured the detailed electronic structure of in-situ grown thin film samples of CuPc. Beam damage was minimized by continuous translation of the sample during data acquisition. The results obtained differ significantly from previous XES and ultraviolet photoemission measurements, but are in excellent agreement with recent density functional calculations. The reasons for these discrepancies will be explained, and their implications for future measurements on similar materials will be explored

  7. Copper canisters for nuclear high level waste disposal. Corrosion aspects

    International Nuclear Information System (INIS)

    Werme, L.; Sellin, P.; Kjellbert, N.

    1992-10-01

    A corrosion analysis of a thick-walled copper canister for spent fuel disposal is discussed. The analysis has shown that there are no rapid mechanisms that may lead to canister failure, indicating an anticipated corrosion service life of several millions years. If further analysis of the copper canister is considered, it should be concentrated on identifying and evaluating processes other than corrosion, which may have a potential for leading to canister failure. (au)

  8. Printing Electronic Components from Copper-Infused Ink and Thermoplastic Mediums

    Science.gov (United States)

    Flowers, Patrick F.

    The demand for printable electronics has sharply increased in recent years and is projected to continue to rise. Unfortunately, electronic materials which are suitable for desired applications while being compatible with available printing techniques are still often lacking. This thesis addresses two such challenging areas. In the realm of two-dimensional ink-based printing of electronics, a major barrier to the realization of printable computers that can run programs is the lack of a solution-coatable non-volatile memory with performance metrics comparable to silicon-based devices. To address this deficiency, I developed a nonvolatile memory based on Cu-SiO2 core-shell nanowires that can be printed from solution and exhibits on-off ratios of 106, switching speeds of 50 ns, a low operating voltage of 2 V, and operates for at least 104 cycles without failure. Each of these metrics is similar to or better than Flash memory (the write speed is 20 times faster than Flash). Memory architectures based on the individual memory cells demonstrated here could enable the printing of the more complex, embedded computing devices that are expected to make up an internet of things. Recently, the exploration of three-dimensional printing techniques to fabricate electronic materials began. A suitable general-purpose conductive thermoplastic filament was not available, however. In this work I examine the current state of conductive thermoplastic filaments, including a newly-released highly conductive filament that my lab has produced which we call Electrifi. I focus on the use of dual-material fused filament fabrication (FFF) to 3D print electronic components (conductive traces, resistors, capacitors, inductors) and circuits (a fully-printed high-pass filter). The resistivity of traces printed from conductive thermoplastic filaments made with carbon-black, graphene, and copper as conductive fillers was found to be 12, 0.78, and 0.014 ohm cm, respectively, enabling the creation of

  9. Influence of thermal annealing on microstructural, morphological, optical properties and surface electronic structure of copper oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Akgul, Funda Aksoy, E-mail: fundaaksoy01@gmail.com [Department of Physics, Nigde University, 51240 Nigde (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Akgul, Guvenc, E-mail: guvencakgul@gmail.com [Bor Vocational School, Nigde University, 51700 Nigde (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Yildirim, Nurcan [Department of Physics Engineering, Ankara University, 06100 Ankara (Turkey); Department of Metallurgical and Materials Engineering, Middle East Technical University, 06800 Ankara (Turkey); Unalan, Husnu Emrah [Department of Metallurgical and Materials Engineering, Middle East Technical University, 06800 Ankara (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Turan, Rasit [Department of Physics, Middle East Technical University, 06800 Ankara (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey)

    2014-10-15

    In this study, effect of the post-deposition thermal annealing on copper oxide thin films has been systemically investigated. The copper oxide thin films were chemically deposited on glass substrates by spin-coating. Samples were annealed in air at atmospheric pressure and at different temperatures ranging from 200 to 600°C. The microstructural, morphological, optical properties and surface electronic structure of the thin films have been studied by diagnostic techniques such as X-ray diffraction (XRD), Raman spectroscopy, ultraviolet–visible (UV–VIS) absorption spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The thickness of the films was about 520 nm. Crystallinity and grain size was found to improve with annealing temperature. The optical bandgap of the samples was found to be in between 1.93 and 2.08 eV. Cupric oxide (CuO), cuprous oxide (Cu{sub 2}O) and copper hydroxide (Cu(OH){sub 2}) phases were observed on the surface of as-deposited and 600 °C annealed thin films and relative concentrations of these three phases were found to depend on annealing temperature. A complete characterization reported herein allowed us to better understand the surface properties of copper oxide thin films which could then be used as active layers in optoelectronic devices such as solar cells and photodetectors. - Highlights: • Effect of post-deposition annealing on copper oxide thin films was investigated. • Structural, optical, and electronic properties of the thin films were determined. • Oxidation states of copper oxide thin films were confirmed by XPS analysis. • Mixed phases of CuO and Cu{sub 2}O were found to coexist in copper oxide thin films.

  10. Towards accurate all-electron quantum Monte Carlo calculations of transition-metal systems: spectroscopy of the copper atom.

    Science.gov (United States)

    Caffarel, Michel; Daudey, Jean-Pierre; Heully, Jean-Louis; Ramírez-Solís, Alejandro

    2005-09-01

    In this work we present all-electron fixed-node diffusion Monte Carlo (FN-DMC) calculations of the low-lying electronic states of the copper atom and its cation. The states considered are those which are the most relevant for the organometallic chemistry of copper-containing systems, namely, the (2)S, (2)D, and (2)P electronic states of Cu and the (1)S ground state of Cu(+). We systematically compare our FN-DMC results to CCSD(T) calculations using very large atomic-natural-orbital-type all-electron basis sets. The FN-DMC results presented in this work provide, to the best of our knowledge, the most accurate nonrelativistic all-electron correlation energies for the lowest-lying states of copper and its cation. To compare our results to experimental data we include the relativistic contributions for all states through numerical Dirac-Fock calculations, which for copper (Z=29) provide almost the entire relativistic effects. It is found that the fixed-node errors using Hartree-Fock nodes for the lowest transition energies of copper and the first ionization potential of the atom cancel out within statistical fluctuations. The overall accuracy achieved with quantum Monte Carlo for the nonrelativistic correlation energy (statistical fluctuations of about 1600 cm(-1) and near cancelation of fixed-node errors) is good enough to reproduce the experimental spectrum when relativistic effects are included. These results illustrate that, despite the presence of the large statistical fluctuations associated with core electrons, accurate all-electron FN-DMC calculations for transition metals are nowadays feasible using extensive but accessible computer resources.

  11. Electronic structure and electron-phonon coupling in layered copper oxide superconductors

    International Nuclear Information System (INIS)

    Pickett, W.E.; Cohen, R.E.; Krakauer, H.

    1991-01-01

    Experimental data on the layered Cu-O superconductors seem more and more to reflect normal Fermi-liquid behavior and substantial correspondence with band structure predictions. Recent self-consistent, microscopic band theoretic calculations of the electronic structure, lattice instabilities, phonon frequencies, and electron-phonon coupling characteristics and strength for La 2 CuO 4 and YBa 2 Cu 3 O 7 are reviewed. A dominant feature of the coupling is a novel Madelung-like contribution which would be screened out in high density of states superconductors but survives in cuprates because of weak screening. Local density functional theory correctly predicts the instability of (La, Ba) 2 CuO 4 to both the low-temperature orthorhombic phase (below room temperature) and the lower-temperature tetragonal phase (below 50 K). (orig.)

  12. Synthesis of nanoscale copper nitride thin film and modification of the surface under high electronic excitation.

    Science.gov (United States)

    Ghosh, S; Tripathi, A; Ganesan, V; Avasthi, D K

    2008-05-01

    Nanoscale (approximately 90 nm) Copper nitride (Cu3N) films are deposited on borosilicate glass and Si substrates by RF sputtering technique in the reactive environment of nitrogen gas. These films are irradiated with 200 MeV Au15+ ions from Pelletron accelerator in order to modify the surface by high electronic energy deposition of heavy ions. Due to irradiation (i) at incident ion fluence of 1 x 10(12) ions/cm2 enhancement of grains, (ii) at 5 x 10912) ions/cm2 mass transport on the films surface, (iii) at 2 x 10(13) ions/cm2 line-like features on Cu3N/glass and nanometallic structures on Cu3N/Si surface are observed. The surface morphology is examined by atomic force microscope (AFM). All results are explained on the basis of a thermal spike model of ion-solid interaction.

  13. Prioritization of copper for the use in photosynthetic electron transport in developing leaves of hybrid poplar

    Directory of Open Access Journals (Sweden)

    Muhammad eShahbaz

    2015-06-01

    Full Text Available Plastocyanin is an essential and abundant copper protein required for photosynthesis in higher plants. Severe copper deprivation has the potential to cause a defect in photosynthetic electron transport due to a lack in plastocyanin. The Cu-microRNAs, which are up-regulated under Cu deficiency, down-regulate the expression of target Cu proteins other than plastocyanin, cytochrome-c oxidase and the ethylene receptors. It has been proposed that this mechanism saves Cu for plastocyanin maturation. We aimed to test how hybrid poplar, a species that has capacity to rapidly expand its photosynthetically active tissue, responds to variations in Cu availability over time. Measurement of chlorophyll fluorescence after Cu depletion revealed a drastic effect on photosynthesis in hybrid poplar. The decrease in photosynthetic capacity was correlated with a reduction in plastocyanin protein levels. Compared to older leaves, plastocyanin decreased more strongly in developing leaves, which also lost more photosynthetic electron transport capacity. The effect of Cu depletion on older and more developed leaves was minor and these leaves maintained much of their photosynthetic capacity. Interestingly, upon resupply of Cu to the medium a very rapid recovery of Cu levels was seen in the younger leaves with a concomitant rise in the expression and activity of plastocyanin. In contrast, the expression of those Cu proteins, which are targets of microRNAs was under the same circumstances delayed. At the same time, Cu resupply had only minor effects on the older leaves. The data suggest a model where rapid recovery of photosynthetic capacity in younger leaves is made possible by a preferred allocation of Cu to plastocyanin in younger leaves, which is supported by Cu-microRNA expression.

  14. Ab initio electronic structure and correlations in pristine and potassium-doped molecular crystals of copper phthalocyanine

    NARCIS (Netherlands)

    Giovannetti, G.; Brocks, G.; van den Brink, J.

    2008-01-01

    We investigate the effect that potassium intercalation has on the electronic structure of copper phthalocyanine (CuPc) molecular crystals by means of ab initio density functional calculations. Pristine CuPc (in its alpha and beta structures) is found to be an insulator containing local magnetic

  15. Radiation enhanced copper clustering processes in Fe-Cu alloys during electron and ion irradiations as measured by electrical resistivity

    International Nuclear Information System (INIS)

    Ishino, S.; Chimi, Y.; Bagiyono; Tobita, T.; Ishikawa, N.; Suzuki, M.; Iwase, A.

    2003-01-01

    To study the mechanism of radiation-enhanced clustering of copper atoms in Fe-Cu alloys, in situ electrical resistivity measurements are performed during irradiation with 100 MeV carbon ions and with 2 MeV electrons at 300 K. Two kinds of highly pure Fe-Cu alloys with Cu content of 0.02 and 0.6 wt% are used. The results are summarized as follows: - Although there is a steep initial resistivity increase below about 10 μdpa, the resistivity steadily decreases after this initial transient in Fe-0.6wt%Cu alloy, while in Fe-0.02wt%Cu alloy, the resistivity either decreases slowly or stays almost constant. The rate of change in resistivity depends on copper concentration. - The rate of change in resistivity per dpa is larger for electron irradiation than for ion irradiation. - Change in dose rate from 10 -8 to 10 -9 dpa/s slightly enhances the rate of resistivity change per dpa. The decrease in resistivity with dose is considered to be due to clustering or precipitation of copper atoms. The initial abrupt increase in resistivity is too large to be accounted for by initial introduction of point defects before copper clustering. Tentatively the phenomenon is explained as due to the formation of embryos of copper precipitates with a large strain field around them. Quantitative evaluation of the results using resistivity contribution of a unit concentration of Frenkel pairs and that of copper atoms gives an important conclusion that more than one copper atom are removed from solid solution by one Frenkel pair. The clustering efficiency is surprisingly high in the present case compared with the ordinary radiation-induced or radiation-enhanced precipitation processes

  16. Long-Term Strength of a Thick-Walled Pipe Filled with an Aggressive Medium, with Account for Damageability of the Pipe Material and Residual Strength

    Science.gov (United States)

    Piriev, S. A.

    2018-01-01

    This paper describes the study of scattered fracture of a thick-walled pipe filled with an aggressive medium, which creates uniform pressure on the inner surface of the pipe. It is assumed that the aggressive medium affects only the value of instantaneous strength. Damageability is described by an integral operator of the hereditary type. The problem is solved with allowance for residual strength of the pipe material behind the fracture front. Numerical calculation is carried out, and relationships between the fracture front coordinate and time for various concentrations of the aggressive medium and residual strength behind the fracture front are constructed.

  17. Preferred diffusion paths for copper electromigration by in situ transmission electron microscopy.

    Science.gov (United States)

    Oh, Young-Hwa; Kim, Sung-Il; Kim, Miyoung; Lee, Seung-Yong; Kim, Young-Woon

    2017-10-01

    Ionic transport in the reverse direction of an electric field is caused by momentum transfer from free electrons to metal ions, i.e., electromigration (EM), which is a critical factor leading to copper (Cu) interconnect failure in integrated circuits under extreme operating conditions. We investigated Cu self-diffusion paths under electrical bias using in situ transmission electron microscopy (TEM). An electric current was applied to multigrain Cu lines in the TEM instrument for durations of up to the order of 10 4 s to trace EM-induced Cu movement around voids and hillocks. Combining this approach with scanning nanobeam diffraction, we observed that high-angle grain boundaries exposed to the free surface are the most favored paths for Cu EM, rather than a specific orientation within the grain. On hillocks of accumulated Cu atoms, we directly observed grain growth, accompanied by the formation of Σ7 high-mobile and Σ3 twin coincidence site lattice boundaries for effective growth. This study provides insight into the EM mechanism to improve the reliability of metal interconnect design. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Recoveries of rare elements Ga, Ge, In and Sn from waste electric and electronic equipment through secondary copper smelting.

    Science.gov (United States)

    Avarmaa, Katri; Yliaho, Simon; Taskinen, Pekka

    2018-01-01

    The recycling and recovery of valuable metals from waste materials is one of the key issues in maintaining the sustainability of base and rare metals. Especially WEEE (Waste Electric and Electronic Equipment) can be considered as a high potential resource for a number of valuable and critical metals like gallium, germanium and indium. During the mechanical processing of WEEE, these metals are primary separated into the non-ferrous scrap fractions, including copper fraction. As a consequence, the behavior of these valuable metals and the possibility of their recycling in secondary copper smelting are of great interest. This study experimentally investigates the distribution behavior of indium, gallium, germanium and tin between metallic copper and lime-free / lime-containing alumina iron silicate slags (L Cu/s [Me] = [Me] Copper /(Me) Slag ), as well as between solid Al-Fe spinel and slags (L sp/s [Me] = {Me} spinel /(Me) slag ). Moreover, the copper-slag-spinel equilibrium systems are examined. The experiments were executed simulating high alumina-bearing copper scrap smelting in typical black copper smelting conditions of pO 2  = 10 -10 -10 -5 atm (1 atm = 1.01325 × 10 5  Pa) and T = 1300 °C. The experimental technique employed utilized a highly advanced equilibration-rapid quenching method followed by Electron Probe Micro-Analysis (EPMA). The results show that tin and indium can be efficiently recovered into the copper phase in reducing process conditions (pO 2 below 10 -7  atm), whereas gallium dissolved preferentially into the solid spinel phase in all conditions examined. Gallium dissolution into slag and spinel was found to occur as GaO 1.5 , whereas indium in spinel was determined to be as InO 1.5 . In addition, germanium was seen to distribute preferentially into the copper phase with L Cu/s [Ge] = 2-4, although its concentrations in all phases present were relatively low. Thus, the main route for germanium can be considered to

  19. Auger electron spectroscopy study of initial stages of oxidation in a copper - 19.6-atomic-percent-aluminum alloy

    Science.gov (United States)

    Ferrante, J.

    1973-01-01

    Auger electron spectroscopy was used to examine the initial stages of oxidation of a polycrystalline copper - 19.6 a/o-aluminum alloy. The growth of the 55-eV aluminum oxide peak and the decay of the 59-, 62-, and 937-eV copper peaks were examined as functions of temperature, exposure, and pressure. Pressures ranged from 1x10 to the minus 7th power to 0.0005 torr of O2. Temperatures ranged from room temperature to 700 C. A completely aluminum oxide surface layer was obtained in all cases. Complete disappearance of the underlying 937-eV copper peak was obtained by heating at 700 C in O2 at 0.0005 torr for 1 hr. Temperature studies indicated that thermally activated diffusion was important to the oxidation studies. The initial stages of oxidation followed a logarithmic growth curve.

  20. Coordination Environment of Copper Sites in Cu-CHA Zeolite Investigated by Electron Paramagnetic Resonance

    DEFF Research Database (Denmark)

    Godiksen, Anita; Stappen, Frederick N.; Vennestrøm, Peter N. R.

    2014-01-01

    Cu-CHA combines high activity for the selective catalytic reduction (SCR) reaction with better hydrothermal stability and selectivity compared to other copper-substituted zeolites. At the same time Cu-CHA offers an opportunity for unraveling the coordination environment of the copper centers since...... of the EPR silent monomeric Cu2+ in copper-substituted zeolites is suggested to be copper species with an approximate trigonal coordination sphere appearing during the dehydration. After complete dehydration at 250 °C the majority of the EPR silent Cu2+ is suggested to exist as Cu2+–OH– coordinated to two...

  1. Copper silicide/silicon nanowire heterostructures: in situ TEM observation of growth behaviors and electron transport properties.

    Science.gov (United States)

    Chiu, Chung-Hua; Huang, Chun-Wei; Chen, Jui-Yuan; Huang, Yu-Ting; Hu, Jung-Chih; Chen, Lien-Tai; Hsin, Cheng-Lun; Wu, Wen-Wei

    2013-06-07

    Copper silicide has been studied in the applications of electronic devices and catalysts. In this study, Cu3Si/Si nanowire heterostructures were fabricated through solid state reaction in an in situ transmission electron microscope (TEM). The dynamic diffusion of the copper atoms in the growth process and the formation mechanism are characterized. We found that two dimensional stacking faults (SF) may retard the growth of Cu3Si. Due to the evidence of the block of edge-nucleation (heterogeneous) by the surface oxide, center-nucleation (homogeneous) is suggested to dominate the silicidation. Furthermore, the electrical transport properties of various silicon channel length with Cu3Si/Si heterostructure interfaces and metallic Cu3Si NWs have been investigated. The observations not only provided an alternative pathway to explore the formation mechanisms and interface properties of Cu3Si/Si, but also suggested the potential application of Cu3Si at nanoscale for future processing in nanotechnology.

  2. Quantitative microstructure characterization of self-annealed copper films with electron backscatter diffraction

    DEFF Research Database (Denmark)

    Pantleon, Karen; Gholinia, A.; Somers, Marcel A. J.

    2008-01-01

    and crystallographic texture of copper films with different thicknesses essentially supplement results from in-situ XRD. Twin relations between neighboring grains were identified from the orientation maps and the observed twin chains confirm multiple twinning in copper electrodeposits as the mechanism...

  3. Electronic cigarette aerosols and copper nanoparticles induce mitochondrial stress and promote DNA fragmentation in lung fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Lerner, Chad A.; Rutagarama, Pierrot; Ahmad, Tanveer; Sundar, Isaac K.; Elder, Alison; Rahman, Irfan, E-mail: irfan_rahman@urmc.rochester.edu

    2016-09-02

    Oxidants or nanoparticles have recently been identified as constituents of aerosols released from various styles of electronic cigarettes (E-cigs). Cells in the lung may be directly exposed to these constituents and harbor reactive properties capable of incurring acute cell injury. Our results show mitochondria are sensitive to both E-cig aerosols and aerosol containing copper nanoparticles when exposed to human lung fibroblasts (HFL-1) using an Air-Liquid Interface culture system, evident by elevated levels of mitochondrial ROS (mtROS). Increased mtROS after aerosol exposure is associated with reduced stability of OxPhos electron transport chain (ETC) complex IV subunit and nuclear DNA fragmentation. Increased levels of IL-8 and IL-6 in HFL-1 conditioned media were also observed. These findings reveal both mitochondrial, genotoxic, and inflammatory stresses are features of direct cell exposure to E-cig aerosols which are ensued by inflammatory duress, raising a concern on deleterious effect of vaping. - Graphical abstract: Oxidants and possibly reactive properties of metal particles in E-cig aerosols impart mitochondrial oxidative stress and DNA damage. These biological effects accompany inflammatory response which may raise concern regarding long term E-cig use. Mitochondria may be particularly sensitive to reactive properties of E-cig aerosols in addition to the potential for them to induce genotoxic stress by generating increased ROS. - Highlights: • Mitochondria are sensitive to both E-cig aerosols and metal nanoparticles. • Increased mtROS by E-cig aerosol is associated with disrupted mitochondrial energy. • E-cig causes nuclear DNA fragmentation. • E-cig aerosols induce pro-inflammatory response in human fibroblasts.

  4. Chemical stability of copper-canisters in deep repository

    International Nuclear Information System (INIS)

    Ahonen, L.

    1995-12-01

    The spent fuel from Finnish nuclear reactors is planned to be encapsulated in thick-walled copper-iron canisters and placed deep into the bedrock. The copper wall of the canister provides a long-time shield against corrosion, preventing the high-level nuclear fuel from contact with ground water. In the report, stability of metallic copper and its possible corrosion reactions in the conditions of deep bedrock are evaluated by means of thermo-dynamic calculations. (90 refs., 28 figs., 11 tabs.)

  5. High-voltage electron-microscope investigation of point-defect agglomerates in irradiated copper during in-situ annealing

    International Nuclear Information System (INIS)

    Jaeger, W.; Urban, K.; Frank, W.

    1980-01-01

    Thin copper foils were irradiated with 650 keV electrons at 10 K in a high-voltage electron microscope (HVEM) to doses phi in the range 2 x 10 23 electrons/m 2 approximately 25 electrons /m 2 and then annealed in situ up to room temperature and outside the HVEM between room temperature and 470 K. During irradiation visible defect clusters were formed only at phi >= 2.5 x 10 24 electrons/m 2 . At smaller doses defect clusters became visible after annealing at 50 K. Between 50 K and 120 K further clusters, mainly dislocation loops on brace111 planes, appeared. Above 120 K, particularly between 160 K and 300 K, some of the dislocation loops became glissile. They glided out of the specimens or agglomerated to larger clusters of frequently complex shapes. As a consequence between 160 K and 300 K the cluster density decreased strongly, whereas the mean cluster size increased monotonously through the entire range of annealing temperatures covered. Contrast analyses between 180 K and 400 K revealed that the great majority of the dislocation loops were of interstitial type. At 470 K a new type of small clusters emerged, presumably of vacancy type. These observations are compared with other studies on electron-irradiated copper and with the current models of radiation damage in metals. (author)

  6. Assembly of coupled redox fuel cells using copper as electron acceptors to generate power and its in-situ retrieval.

    Science.gov (United States)

    Zhang, Hui-Min; Xu, Wei; Li, Gang; Liu, Zhan-Meng; Wu, Zu-Cheng; Li, Bo-Geng

    2016-02-15

    Energy extraction from waste has attracted much interest nowadays. Herein, a coupled redox fuel cell (CRFC) device using heavy metals, such as copper, as an electron acceptor is assembled to testify the recoveries of both electricity and the precious metal without energy consumption. In this study, a NaBH4-Cu(II) CRFC was employed as an example to retrieve copper from a dilute solution with self-electricity production. The properties of the CRFC have been characterized, and the open circuit voltage was 1.65 V with a maximum power density of 7.2 W m(-2) at an initial Cu(2+) concentration of 1,600 mg L(-1) in the catholyte. 99.9% of the 400 mg L(-1) copper was harvested after operation for 24 h, and the product formed on the cathode was identified as elemental copper. The CRFC demonstrated that useful chemicals were recovered and the electricity contained in the chemicals was produced in a self-powered retrieval process.

  7. An electron paramagnetic resonance study of the behaviour of copper (II) in ageing catechin-based model wines

    International Nuclear Information System (INIS)

    Mitri, M.; Scollary, G.R.; Troup, G.J.; Hutton, D.R.; Hunter, C.A.; Hewitt, D.G.

    1996-01-01

    This poster reports an electron paramagnetic resonance (EPR) study of copper in a model white wine. The model consists of a saturated 12% ethanol solution of potassium hydrogen tartrate solution (the 'wine base') containing copper and catechin as the oxidizable substrate. Ascorbic acid, as a supposed anti-oxidant, was added to some solutions. A Varian E-12 EPR spectrometer (∼9.1 GHz frequency) with quartz sample tubes was used and spectra were recorded at liquid nitrogen temperature to avoid polar water losses. Solutions were examined on four successive days whilst kept at room temperature and subsequently every third day when stored at 45 degree C. Variations in signal intensity, linewidth and form will be shown and the changes related to the degree of browning, as measured by visible absorption spectroscopy at 440 nm. The ESP spectra of the brown deposits reveal that the copper (II) ion is in a low symmetry site and a well defined free radical signal was also observed. No free radical signal was found in solutions containing copper and catechin, indicating that a high degree of polymerization of the oxidized catechin is required to stabilize the free radical species

  8. Assembly of coupled redox fuel cells using copper as electron acceptors to generate power and its in-situ retrieval

    Science.gov (United States)

    Zhang, Hui-Min; Xu, Wei; Li, Gang; Liu, Zhan-Meng; Wu, Zu-Cheng; Li, Bo-Geng

    2016-02-01

    Energy extraction from waste has attracted much interest nowadays. Herein, a coupled redox fuel cell (CRFC) device using heavy metals, such as copper, as an electron acceptor is assembled to testify the recoveries of both electricity and the precious metal without energy consumption. In this study, a NaBH4-Cu(II) CRFC was employed as an example to retrieve copper from a dilute solution with self-electricity production. The properties of the CRFC have been characterized, and the open circuit voltage was 1.65 V with a maximum power density of 7.2 W m-2 at an initial Cu2+ concentration of 1,600 mg L-1 in the catholyte. 99.9% of the 400 mg L-1 copper was harvested after operation for 24 h, and the product formed on the cathode was identified as elemental copper. The CRFC demonstrated that useful chemicals were recovered and the electricity contained in the chemicals was produced in a self-powered retrieval process.

  9. A thick-walled sphere rotating in a uniform magnetic field: The next step to de-spin a space object

    Science.gov (United States)

    Nurge, Mark A.; Youngquist, Robert C.; Caracciolo, Ryan A.; Peck, Mason; Leve, Frederick A.

    2017-08-01

    Modeling the interaction between a moving conductor and a static magnetic field is critical to understanding the operation of induction motors, eddy current braking, and the dynamics of satellites moving through Earth's magnetic field. Here, we develop the case of a thick-walled sphere rotating in a uniform magnetic field, which is the simplest, non-trivial, magneto-statics problem that leads to complete closed-form expressions for the resulting potentials, fields, and currents. This solution requires knowledge of all of Maxwell's time independent equations, scalar and vector potential equations, and the Lorentz force law. The paper presents four cases and their associated experimental results, making this topic appropriate for an advanced student lab project.

  10. Tuning copper-dioxygen reactivity and exogenous substrate oxidations via alterations in ligand electronics.

    Science.gov (United States)

    Zhang, Christiana Xin; Liang, Hong-Chang; Kim, Eun-Il; Shearer, Jason; Helton, Matthew E; Kim, Eunsuk; Kaderli, Susan; Incarvito, Christopher D; Zuberbühler, Andreas D; Rheingold, Arnold L; Karlin, Kenneth D

    2003-01-22

    Copper(I)-dioxygen adducts are important in biological and industrial processes. For the first time we explore the relationship between ligand electronics, CuI-O2 adduct formation and exogenous substrate reactivity. The copper(I) complexes [CuI(R-MePY2)]+ (1R, where R = Cl, H, MeO, Me2N) were prepared; where R-MePY2 are 4-pyridyl substituted bis[2-(2-pyridyl)ethyl]methylamine chelates. Both the redox potential of 1R (ranging from E1/2 = -270 mV for 1Cl to -440 mV for 1MeN vs FeCp2/FeCp2+) and nuCO of the CO adducts of 1R (ranging from 2093 cm-1 for 1Cl-CO to 2075 cm-1 for 1Me2N-CO) display modest but expected systematic shifts. Dioxygen readily reacts with 1H, 1MeO, and 1Me2N, forming the side-on peroxo-CuII2 complexes [{CuII(R-MePY2)}2(O2)]2+ (2R, also containing some bis-mu-oxo-CuIII2 isomer), but there is no reaction with 1Cl. Stopped-flow studies in dichloromethane show that the formation of 2Me2N from dioxygen and 1Me2N proceeds with a k = 8.2(6) x 104 M-2 s-1 (183 K, DeltaH = -20.3(6) kJ mol-1, DeltaS = -219(3) J mol-1 K-1). Solutions of 2R readily oxidize exogenous substrates (9,10-dihydroanthracene --> anthracene, tetrahydrofuran (THF) --> 2-hydroxytetrahydrofuran (THF-OH), N,N-dimethylaniline --> N-methylaniline and formaldehyde, benzyl alcohol --> benzaldehyde, benzhydrol --> benzophenone, and methanol --> formaldehyde), forming the bis-mu-hydroxo-CuII2 complexes [{CuII(R-MePY2)(OH)}2]2+ (3R). Product yields increase as the R-group is made more electron-donating, and in some cases are quantitative with 2Me2N. Pseudo-first-order rate constants for THF and methanol oxidation reactions demonstrate a remarkable R-group dependence, again favoring the strongest ligand donor (i.e., R = Me2N). For THF oxidation to THF-OH a nearly 1500-fold increase in reaction rate is observed (kobs = 2(1) x 10-5 s-1 for 2H to 3(1) x 10-2 s-1 for 2Me2N), while methanol oxidation to formaldehyde exhibits an approximately 2000-fold increase (kobs = 5(1) x 10-5 s-1 for 2H to 1(1) x

  11. The BiCu{sub 1−x}OS oxysulfide: Copper deficiency and electronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Berthebaud, D.; Guilmeau, E.; Lebedev, O.I. [Laboratoire CRISMAT, UMR 6508 CNRS/ENSICAEN/UCBN, 6 bd du Maréchal Juin, F-14050 CAEN Cedex 4 (France); Maignan, A., E-mail: antoine.maignan@ensicaen.fr [Laboratoire CRISMAT, UMR 6508 CNRS/ENSICAEN/UCBN, 6 bd du Maréchal Juin, F-14050 CAEN Cedex 4 (France); Gamon, J.; Barboux, P. [Institut de Recherche de Chimie de Paris, Ecole Nationale Supérieure de Chimie de Paris, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 09 France (France)

    2016-05-15

    An oxysulfide series of nominal compositions BiCu{sub 1−x}OS with x<0.20 has been prepared and its structural properties characterized by combining powder X-ray diffraction and transmission electron microscopy techniques. It is found that this oxysulfide, crystallizing in the P4/nmm space group, tends to adopt a constant amount of copper vacancy corresponding to x=0.05 in the BiCu{sub 1−x}OS formula. The presence of Cu vacancies is confirmed by HAADF-STEM analysis showing, in the Cu atomic columns, alternating peaks of different intensities in some very localized regions. For larger Cu deficiencies (x>0.05 in the nominal composition), other types of structural nanodefects are evidenced such as bismuth oxysulfides of the “BiOS” ternary system which might explain the report of superconductivity for the BiCu{sub 1−x}OS oxysulfide. Local epitaxial growth of the BiCuOS oxysulfide on top of CuO is also observed. In marked contrast to the BiCu{sub 1−x}OSe oxyselenide, these results give an explanation to the limited impact of Cu deficiency on the Seebeck coefficient in BiCu{sub 1−x}OS compounds. - Graphical abstract: High resolution TEM image showing a Bi(Cu)OS/Bi{sub 2}O{sub 2}S interface and corresponding dislocation region. The Bi(Cu)OS structure adopts a rather constant Cu content (near 0.95); starting from BiCuOS leads to the formation of defects such as the Bi{sub 2}O{sub 2}S oxysulfide.

  12. Copper in plants

    OpenAIRE

    Yruela, Inmaculada

    2005-01-01

    Copper is an essential metal for normal plant growth and development, although it is also potentially toxic. Copper participates in numerous physiological processes and is an essential cofactor for many metalloproteins, however, problems arise when excess copper is present in cells. Excess copper inhibits plant growth and impairs important cellular processes (i.e., photosynthetic electron transport). Since copper is both an essential cofactor and a toxic element, involving a complex network o...

  13. Indicators for the feasibility of WEEE processing plants in brazil: a relationship between virgin mineral copper ore and the recycling of consumer electronic products

    Directory of Open Access Journals (Sweden)

    Luis Henrique Alves Cândido

    2015-07-01

    Full Text Available This paper assesses the economic analysis of the implementation of WEEE – Waste Electrical and Electronic Equipment Directive – processing plants in Brazil, through the study of potential copper extraction from this secondary source. A comparative approach was performed on its copper grade related to levels of its virgin ore mineral extracted from mines located in Brazil, in the United States and through a global average. The results demonstrate that the amount of copper mass originated from the recycling of disassembly of twenty electronic products ranges from 0.24% to 17.83% of its total mass, with an average of 3.63% of copper. In eighteen of these products, values greater than 0.4% were found, which surpass current levels of copper in ore mines in the USA. In fourteen products, these rates exceed the index of 1.5% copper in the ore, considered the minimum rate for the feasibility of opening new units of copper underground mining in Brazil. Thus, this paper shows the economic analysis that aims to guide on the viability of deploying WEEE processing plants, focusing on the expansion of recycling and reuse of copper by the processing industry.

  14. Lifetime assessment of thick-walled components made of nickel-base alloys under near-service loading conditions; Lebensdauerbewertung dickwandiger Bauteile aus Nickelbasislegierungen unter betriebsnahen Beanspruchungen

    Energy Technology Data Exchange (ETDEWEB)

    Hueggenberg, Daniel

    2015-11-06

    and the transmission electron microscope for the base raw material, the creep and creep-fatigue exposed material. For the classification the investigation results were compared to the results of the other projects and no differences could be identified. For the description of the deformation and damage behavior under creep-fatigue loading with finite elements simulations a viscoplastic deformation model with an integrated damage model of Lemaitre was used. The material dependent model parameters were fitted under consideration of the basis characterization test results of the Alloy 617 mod. and Alloy 263. All basis characterization tests are simulated with finite elements to classify the parameter fittings. The verification of the fitted material models was carried out by simulations of the complex lab tests. From the comparison of the simulation and test results it is obvious that the deformation and damage behavior can be reproduced with the used material model in a good manner. With finite element simulations of complex thick-walled components (header, formed part) under realistic thermal and mechanic loading conditions could be shown that the viscoplastic material model fitted for the Alloy 617 mod. and Alloy 263 is able to predict the locations of the maximum loadings and the lifetime until the first cracks appear. This could be confirmed by dye penetrant testing on the one hand and destructive investigations of two fracture surfaces of the header on the other hand. Additionally the approaches of the European DIN EN 12952-3/4, the American ASME Section III Division 1 Subsection NH, the French RCC-MR RB 3262.12 and the British R5 recommendations Volume 2/3 are used to predict the lifetimes. It can be seen that the approaches of ASME and RCC-MR provide very conservative predictions and that the approaches of R5 and DIN EN 12952 provide non-conservative predictions. These results lead to the conclusion that no approach of the standards/recommendation is suitable for

  15. Determination of the electron self-exchange rates of blue copper proteins by super-WEFT NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ma Lixin; Philipp, Else; Led, Jens J. [University of Copenhagen, H.C. Orsted Institute, Department of Chemistry (Denmark)

    2001-03-15

    An NMR approach for determining the electron self-exchange (ESE) rate constants in blue copper proteins is presented. The approach uses the paramagnetic relaxation enhancement of resonances in 1D {sup 1}H super-WEFT spectra of partly oxidized (paramagnetic) proteins. These spectra allow a more precise determination of the relevant paramagnetic linebroadenings than conventional 1D {sup 1}H spectra and, thus, permit a more detailed investigation of the applicability of the linebroadenings for determining the electron exchange rates. The approach was used to estimate the ESE rate constant of plastocyanin from Anabaena variabilis. It was found that, although the rate constant can be determined accurately from a series of resonances, precise but erroneous constants are obtained from the resonances of the copper-bound residues, unless a narrow splitting of these resonances caused by the presence of two conformations is taken into account. As demonstrated here, this complication can be overcome by a correct analysis of the paramagnetic broadening of the combined double signals. Because of the high resolution and specific sensitivity of the approach it should be generally applicable to estimate electron transfer rates, k, if the paramagnetic relaxation enhancement R{sub 2p} of the resonances can be determined, and the conditions k<<>k>>R{sub 2p} are fulfilled, {delta}{omega}{sub p} being the frequency separation between corresponding diamagnetic and paramagnetic sites.

  16. Ordered Assembly and Controlled Electron Transfer of the Blue Copper Protein Azurin at Gold (111) Single-Crystal Substrates

    DEFF Research Database (Denmark)

    Chi, Qijin; Zhang, Jingdong; Andersen, Jens Enevold Thaulov

    2001-01-01

    or monolayers. In this orientation mode azurin molecules on Au(111) are oriented with the redox center (copper atom) facing the electrode surface. This is opposite to the orientation of azurin on bare gold which is via a surface disulfide group such as recently reported. Scanning tunneling microscopy (STM......) with molecular resolution reveals that both well-ordered alkanethiol and protein adlayers are present. Adsorbed azurin molecules exhibit high stability and retain electron transfer (ET) function. Long-range interfacial ET between azurin and Au(111) across variable-length alkanethiol bridges was systematically...

  17. Modification of surface layers of copper under the action of the volumetric discharge initiated by an avalanche electron beam in nitrogen and CO2 at atmospheric pressure

    Science.gov (United States)

    Shulepov, M. A.; Akhmadeev, Yu. Kh.; Tarasenko, V. F.; Kolubaeva, Yu. A.; Krysina, O. V.; Kostyrya, I. D.

    2011-05-01

    The results of experimental investigations of the action of the volumetric discharge initiated by an avalanche electron beam on the surface of copper specimens are presented. The volumetric (diffuse) discharge in nitrogen and CO2 at atmospheric pressure was initiated by applying high voltage pulses of nanosecond duration to a tubular foil cathode. It has been found that the treatment of a copper surface by this type of discharge increases the hardness of the surface layer due to oxidation.

  18. Electron microscopic study on pyrolysis of CCA (chromium, copper and arsenic oxide)-treated wood

    NARCIS (Netherlands)

    Hata, T.; Bronsveld, P.M; Vystavel, T.; Kooi, B.J.; de Hosson, J.T.M.; Kakitani, T.; Otono, A.; Imamura, Y.

    The effectiveness of pyrolysis as a possible technique for disposing of CCA (chromium, copper and arsenic oxide)-treated wood was studied. A CCA-treated sample given an extra heat treatment at 450 degreesC for 10 min was thoroughly investigated in order to establish the details of the reaction in

  19. Auger electron spectroscopy study of surface segregation in the binary alloys copper-1 atomic percent indium, copper-2 atomic percent tin, and iron-6.55 atomic percent silicon

    Science.gov (United States)

    Ferrante, J.

    1973-01-01

    Auger electron spectroscopy was used to examine surface segregation in the binary alloys copper-1 at. % indium, copper-2 at. % tin and iron-6.55 at. % silicon. The copper-tin and copper-indium alloys were single crystals oriented with the /111/ direction normal to the surface. An iron-6.5 at. % silicon alloy was studied (a single crystal oriented in the /100/ direction for study of a (100) surface). It was found that surface segregation occurred following sputtering in all cases. Only the iron-silicon single crystal alloy exhibited equilibrium segregation (i.e., reversibility of surface concentration with temperature) for which at present we have no explanation. McLean's analysis for equilibrium segregation at grain boundaries did not apply to the present results, despite the successful application to dilute copper-aluminum alloys. The relation of solute atomic size and solubility to surface segregation is discussed. Estimates of the depth of segregation in the copper-tin alloy indicate that it is of the order of a monolayer surface film.

  20. Using Fourier and Taylor series expansion in semi-analytical deformation analysis of thick-walled isotropic and wound composite structures

    Directory of Open Access Journals (Sweden)

    Jiran L.

    2016-06-01

    Full Text Available Thick-walled tubes made from isotropic and anisotropic materials are subjected to an internal pressure while the semi-analytical method is employed to investigate their elastic deformations. The contribution and novelty of this method is that it works universally for different loads, different boundary conditions, and different geometry of analyzed structures. Moreover, even when composite material is considered, the method requires no simplistic assumptions. The method uses a curvilinear tensor calculus and it works with the analytical expression of the total potential energy while the unknown displacement functions are approximated by using appropriate series expansion. Fourier and Taylor series expansion are involved into analysis in which they are tested and compared. The main potential of the proposed method is in analyses of wound composite structures when a simple description of the geometry is made in a curvilinear coordinate system while material properties are described in their inherent Cartesian coordinate system. Validations of the introduced semi-analytical method are performed by comparing results with those obtained from three-dimensional finite element analysis (FEA. Calculations with Fourier series expansion show noticeable disagreement with results from the finite element model because Fourier series expansion is not able to capture the course of radial deformation. Therefore, it can be used only for rough estimations of a shape after deformation. On the other hand, the semi-analytical method with Fourier Taylor series expansion works very well for both types of material. Its predictions of deformations are reliable and widely exploitable.

  1. Quantitative determination of copper in a glass matrix using double pulse laser induced breakdown and electron paramagnetic resonance spectroscopic techniques.

    Science.gov (United States)

    Khalil, Ahmed A I; Morsy, Mohamed A

    2016-07-01

    A series of lithium-lead-borate glasses of a variable copper oxide loading were quantitatively analyzed in this work using two distinct spectroscopic techniques, namely double pulse laser induced breakdown spectroscopy (DP-LIBS) and electron paramagnetic resonance (EPR). DP-LIBS results measured upon a combined nanosecond lasers irradiation running at 266nm and 1064nm pulses of a collinear configuration directed to the surface of borate glass samples with a known composition. This arrangement was employed to predict the electron's temperature (Te) and density (Ne) of the excited plasma from the recorded spectra. The intensity of elements' responses using this scheme is higher than that of single-pulse laser induced breakdown spectroscopy (SP-LIBS) setup under the same experimental conditions. On the other hand, the EPR data shows typical Cu (II) EPR-signals in the borate glass system that is networked at a distorted tetragonal Borate-arrangement. The signal intensity of the Cu (II) peak at g⊥=2.0596 has been used to quantify the Cu-content accurately in the glass matrix. Both techniques produced linear calibration curves of Cu-metals in glasses with excellent linear regression coefficient (R(2)) values. This study establishes a good correlation between DP-LIBS analysis of glass and the results obtained using EPR spectroscopy. The proposed protocols prove the great advantage of DP-LIBS system for the detection of a trace copper on the surface of glasses. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Effect of Post Weld Heat Treatment on Corrosion Behavior of AA2014 Aluminum – Copper Alloy Electron Beam Welds

    Science.gov (United States)

    Venkata Ramana, V. S. N.; Mohammed, Raffi; Madhusudhan Reddy, G.; Srinivasa Rao, K.

    2018-03-01

    The present work pertains to the study of corrosion behavior of aluminum alloy electron beam welds. The aluminium alloy used in the present study is copper containing AA2014 alloy. Electron Beam Welding (EBW) was used to weld the alloys in annealed (O) condition. Microstructural changes across the welds were recorded and the effect of post weld heat treatment (PWHT) in T4 (Solutionized and naturally aged) condition on pitting corrosion resistance was studied. A software based PAR basic electrochemical system was used for potentio-dynamic polarization tests. From the study it is observed that weld in O condition is prone to more liquation than that of PWHT condition. This may be attributed to re-melting and solidification of excess eutectic present in the O condition of the base metal. It was also observed that slightly higher hardness values are recorded in O condition than that of PWHT condition. The pitting corrosion resistance of the PMZ/HAZ in PWHT condition is better than that of O condition. This is attributed to copper segregation at the grain boundaries of PMZ in O condition.

  3. Atomic and electronic structure of a copper/graphene interface as prepared and 1.5 years after

    Science.gov (United States)

    Boukhvalov, D. W.; Bazylewski, P. F.; Kukharenko, A. I.; Zhidkov, I. S.; Ponosov, Yu. S.; Kurmaev, E. Z.; Cholakh, S. O.; Lee, Y. H.; Chang, G. S.

    2017-12-01

    We report the results of X-ray spectroscopy and Raman measurements of as-prepared graphene on a high quality copper surface and the same materials after 1.5 years under different conditions (ambient and low humidity). The obtained results were compared with density functional theory calculations of the formation energies and electronic structures of various structural defects in graphene/Cu interfaces. For evaluation of the stability of the carbon cover, we propose a two-step model. The first step is oxidation of the graphene, and the second is perforation of graphene with the removal of carbon atoms as part of the carbon dioxide molecule. Results of the modeling and experimental measurements provide evidence that graphene grown on high-quality copper substrate becomes robust and stable in time (1.5 years). However, the stability of this interface depends on the quality of the graphene and the number of native defects in the graphene and substrate. The effect of the presence of a metallic substrate with defects on the stability and electronic structure of graphene is also discussed

  4. A monomeric copper-phosphoramide complex: synthesis, structure, and electronic properties

    Czech Academy of Sciences Publication Activity Database

    Henriques, Margarida Isabel Sousa; Gorbunov, D.I.; Ponomaryov, A.Y.; Saneei, A.; Pourayoubi, M.; Dušek, Michal; Zvyagin, S.; Uhlarz, M.; Wosnitza, J.

    2016-01-01

    Roč. 118, Nov (2016), s. 154-158 ISSN 0277-5387 R&D Projects: GA ČR(CZ) GA14-03276S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : phosphoramide * magnetization * EPR * mononuclear copper complex * crystal structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.926, year: 2016

  5. Thermal Management of Transient Power Spikes in Electronics - Phase Change Energy Storage or Copper Heat Sinks?

    OpenAIRE

    Krishnan, S.; Garimella, S V

    2004-01-01

    A transient thermal analysis is performed to investigate thermal control of power semiconductors using phase change materials, and to compare the performance of this approach to that of copper heat sinks. Both the melting of the phase change material under a transient power spike input, as well as the resolidification process, are considered. Phase change materials of different kinds (paraffin waxes and metallic alloys) are considered, with and without the use of thermal conductivity enhancer...

  6. Symmetry-adapted-cluster configuration-interaction and equation-of-motion coupled-cluster studies of electronically excited states of copper tetrachloride and copper tetrabromide dianions

    International Nuclear Information System (INIS)

    Ehara, Masahiro; Piecuch, Piotr; Lutz, Jesse J.; Gour, Jeffrey R.

    2012-01-01

    Graphical abstract: Electronically excited states of CuCl 4 2- and CuBr 4 2- are determined using the scalar relativistic symmetry-adapted-cluster configuration-interaction and equation-of-motion coupled-cluster calculations. The results are compared with experimental spectra. Highlights: ► Electronic spectra of CuCl 4 2- and CuBr 4 2- are examined by SAC-CI and EOMCC methods. ► Relativistic SAC-CI and EOMCC results are compared with experimental spectra. ► An assignment of bands in the CuCl 4 2- and CuBr 4 2- absorption spectra is obtained. ► Relativistic effects affect excitation energies and ground-state geometries. ► The effect of relativity on the oscillator strengths is generally small. - Abstract: The valence excitation spectra of the copper tetrachloride and copper tetrabromide open-shell dianions, CuCl 4 2- and CuBr 4 2- , respectively, are investigated by a variety of symmetry-adapted-cluster configuration-interaction (SAC-CI) and equation-of-motion coupled-cluster (EOMCC) methods. The valence excited states of the CuCl 4 2- and CuBr 4 2- species that correspond to transitions from doubly occupied molecular orbitals (MOs) to a singly occupied MO (SOMO), for which experimental spectra are available, are examined with the ionized (IP) variants of the SAC-CI and EOMCC methods. The higher-energy excited states of CuCl 4 2- and CuBr 4 2- that correspond to transitions from SOMO to unoccupied MOs, which have not been characterized experimentally, are determined using the electron-attached (EA) SAC-CI and EOMCC approaches. An emphasis is placed on the scalar relativistic SAC-CI and EOMCC calculations based on the spin-free part of the second-order Douglass–Kroll–Hess Hamiltonian (DKH2) and on a comparison of the results of the IP and EA SAC-CI and EOMCC calculations with up to 2-hole-1-particle (2h-1p) and 2-particle-1-hole (2p-1h) excitations, referred to as the IP-SAC-CI SD-R and IP-EOMCCSD(2h-1p) methods in the IP case and EA-SAC-CI SD-R and EA

  7. Absorbed Dose Distributions in Small Copper Wire Insulation due to Multiple-Sided Irradiations by 0.4 MeV Electrons

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.; Pedersen, Walther Batsberg

    1979-01-01

    When scanned electron beams are used to crosslink polymeric insulation of wire and cable, an important goal is to achieve optimum uniformity of absorbed dose distributions. Accurate measurements of dose distributions in a plastic dosimeter simulating a typical insulating material (polyethylene......) surrounding a copper wire core show that equal irradiations from as few as four sides give approximately isotropy and satisfactorily uniform energy depositions around the wire circumference. Electron beams of 0.4 MeV maximum energy were used to irradiate wires having a copper core of 1.0 mm dia...... and depth-dose profiles could be determined....

  8. Simulation of bending stress variation in long buried thick-walled pipes under the earth’s movement using combined linear dynamics and beam theories

    Directory of Open Access Journals (Sweden)

    Salau Tajudeen A.O.

    2014-01-01

    Full Text Available This study reported a simulation approach to the understanding of the interactions between a buried pipe and the soil system by computing the bending stress variation of harmonically-excited buried pipes. The established principles of linear dynamics theory and simple beam theory were utilised in the analysis of the problem of buried pipe bending stress accumulation and its dynamics. With regards to the parameters that influence the bending stress variations, the most important are the isolation factor, uniform external load, and the corresponding limiting conditions. The simulated mathematical expressions, containing static and dynamic parameters of the buried pipe and earth, were coded in Fortran programming language and applied in the simulation experiment. The results obtained showed that harmonically-excited buried thick-walled pipe became stable and effective when the ratio of the natural frequency of vibration to the forced frequency is greater than 2.0, whenever the damped factor is used as the control parameter for the maximum bending stress. The mirror image of the stress variation produces variation in the location of the maximum bending stress in quantitative terms. The acceptable pipe materials for the simulated cases must have yield strength in bending greater than or equal to 13.95 MPa. The results obtained in this work fill a gap in the literature and will be useful to pipeline engineers and designers, as well as to environmental scientists in initialising and controlling environmental issues and policy formulation concerning the influence of buried pipe on the soil and water in the environment.

  9. Relativistic Density Functional Theory Calculations of the Electron Paramagnetic Resonance Parameters for Vanadyl Acetyl Acetonate and Copper Acetyl Acetonate

    Science.gov (United States)

    Mainali, Laxman; Sahu, Indra; Earle, Keith

    2008-03-01

    Relativistic density functional theory calculations of electron paramagnetic resonance (EPR) parameters using a variety of basis sets have been computed for the model systems Vanadyl acetyl acetonate and Copper acetyl acetonate using the ORCA program. The basis set dependence of g and A tensor calculations for Vanadyl acetyl acetonate and Copper acetyl acetonate were studied using Pople Style and Ahlrichs basis sets in Local and gradient corrected functionals (BP86 and PWP) and Hybrid functionals (B3LYP and PW1PW). The PW1PW hybrid functional gives the best values for VO(acac)2 using the TZV basis set and for Cu(acac)2 using the 6-311G(d) basis set. The calculated A values with PW1PW hybrid functional for VO(acac)2 and Local and gradient corrected functional (BP86) for Cu(acac)2 with same basis set (DZ) give better results than previously reported values using the Amsterdam Density Functional Theory (ADF) Software. Our calculated g and A tensor values are in good agreement with the values determined from experiment.

  10. Pulse-radiolysis studies on the interaction of one-electron reduced species with blue oxidases. Reduction of native and type-2-copper-depleted Vietnamese-lacquer-tree and Japanese-lacquer-tree laccases.

    Science.gov (United States)

    O'Neill, P; Fielden, E M; Morpurgo, L; Agostinelli, E

    1984-01-01

    The interactions of one-electron reduced metronidazole (ArNO2.-) and O2.- with native and Type-2-copper-depleted Vietnamese- and Japanese-lacquer-tree laccases were studied in aqueous solution at pH 6.0 and 7.4 by using the technique of pulse radiolysis. On reaction with ArNO2.-, in the absence of O2, the holo- and the Type-2-copper-depleted proteins accept, with reduction of Type 1 copper, 2 and 1 reducing equivalents respectively. On reaction with O2.- of both holo- and Type-2-copper-depleted Vietnamese-lacquer-tree laccase, almost complete reduction of Type 1 copper was observed and, after completion of the reaction, some (less than 20%) reoxidation of Type 1 copper occurs. Reduction of Type 1 copper of the laccases by these one-electron donors occurs via a bimolecular step; however, the rate of reduction of Vietnamese-lacquer-tree laccase is over 10 times that of Japanese-lacquer-tree laccase. It is inferred that electrons enter the protein via Type 1 copper with, in the case of the holoprotein, subsequent rapid intramolecular transfer of 1 reducing equivalent within the protein. Furthermore it is suggested that intra-molecular electron transfer to Type 3 copper atoms is slow and, in the case of Type-2-copper-depleted protein, may not occur. This slow process may partially account for the variation of the catalytic activities of 'blue' oxidases. PMID:6089764

  11. Thermal effects in equilibrium surface segregation in a copper/10-atomic-percent-aluminum alloy using Auger electron spectroscopy

    Science.gov (United States)

    Ferrante, J.

    1972-01-01

    Equilibrium surface segregation of aluminum in a copper-10-atomic-percent-aluminum single crystal alloy oriented in the /111/ direction was demonstrated by using Auger electron spectroscopy. This crystal was in the solid solution range of composition. Equilibrium surface segregation was verified by observing that the aluminum surface concentration varied reversibly with temperature in the range 550 to 850 K. These results were curve fitted to an expression for equilibrium grain boundary segregation and gave a retrieval energy of 5780 J/mole (1380 cal/mole) and a maximum frozen-in surface coverage three times the bulk layer concentration. Analyses concerning the relative merits of sputtering calibration and the effects of evaporation are also included.

  12. Structural, optical and electronic properties of indium sulfide compositions under influence of copper impurity produced by chemical method

    Directory of Open Access Journals (Sweden)

    Parisa Esmaili

    Full Text Available Aqueous solutions with 70 °C and pH = 2.5 constant values were prepared from convenient chemical compounds to produce In2S3: Cu crystals and thin films. Crystal compositions were grown in this solution under special conditions. Micrographs showed amorphous In2S3 orange powder and transparent vitreous pieces of CuInS2 crystals. Indium sulfide films were produced using the same solution in CBD method, on the glass substrates at different [Cu/In] molar ratio concentrations. Cu+ ions by different concentration doped from copper chloride source into In2S3 films. The produced films were post-annealed at 400 °C for about 1 h. Their crystallography, phase transitions, element analysis and nanostructures were investigated by X-ray diffraction, SEM, EDAX and AFM analyses. β-In2S3 phase was dominant and by doping copper impurity, XRD results suggested the formation of CuInS2 compositions. Morphology of the films, nano-structures, grain shapes and hardness was changed.Optical reflectance was measured in the UV-VIS wavelength range by a spectrophotometer. Other optical properties and optical band gaps were calculated using Kramers-Kronig relations on reflectivity curves. Electronic properties were calculated by full potential linearized augmented plane wave (FP-LAPW method within density functional theory (DFT. In this approach, generalized gradient approximation (GGA was used for the exchange-correlation potential calculation. Band gap structures, density of states and imaginary parts of dielectric function were calculated for In2S3: Cu compositions. Keywords: CuInS2, Structural properties, Optical properties, Electronic properties, Doping, Kramers-Kronig

  13. Investigation of Electronic and Opto-Electronic Properties of Two-Dimensional (2D) Layers of Copper Indium Selenide Field Effect Transistors

    Science.gov (United States)

    Patil, Prasanna Dnyaneshwar

    Investigations performed in order to understand the electronic and optoelectronic properties of field effect transistors based on few layers of 2D Copper Indium Selenide (CuIn7Se11) are reported. In general, field effect transistors (FETs), electric double layer field effect transistors (EDL-FETs), and photodetectors are crucial part of several electronics based applications such as tele-communication, bio-sensing, and opto-electronic industry. After the discovery of graphene, several 2D semiconductor materials like TMDs (MoS2, WS2, and MoSe2 etc.), group III-VI materials (InSe, GaSe, and SnS2 etc.) are being studied rigorously in order to develop them as components in next generation FETs. Traditionally, thin films of ternary system of Copper Indium Selenide have been extensively studied and used in optoelectronics industry as photoactive component in solar cells. Thus, it is expected that atomically thin 2D layered structure of Copper Indium Selenide can have optical properties that could potentially be more advantageous than its thin film counterpart and could find use for developing next generation nano devices with utility in opto/nano electronics. Field effect transistors were fabricated using few-layers of CuIn7Se11 flakes, which were mechanically exfoliated from bulk crystals grown using chemical vapor transport technique. Our FET transport characterization measurements indicate n-type behavior with electron field effect mobility microFE ≈ 36 cm2 V-1 s-1 at room temperature when Silicon dioxide (SiO2) is used as a back gate. We found that in such back gated field effect transistor an on/off ratio of 104 and a subthreshold swing ≈ 1 V/dec can be obtained. Our investigations further indicate that Electronic performance of these materials can be increased significantly when gated from top using an ionic liquid electrolyte [1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6)]. We found that electron field effect mobility microFE can be increased from

  14. The effects of 500 keV electron irradiation and subsequent annealing on 1/f noise in copper films

    International Nuclear Information System (INIS)

    Pelz, J.; Clarke, J.

    1986-01-01

    Polycrystalline copper films were maintained at 90K on the cold stage of an electron microscope and irradiated with 500keV electrons to induce defects. With an electron dose of about 5 x 10 20 cm -2 , the spectral density of the noise voltage across the films increased by an order of magnitude while the electrical resistivity increased by at most 10%. The films were annealed at progressively higher temperatures; after each annealing process the 1/f noise and resistivity were remeasured at 90K. Both the 1/f noise and resistivity were reduced, but at the lower annealing temperatures the fractional reduction in the added noise was substantially more than in the added resistivity. These results suggest that a large fraction of the added noise may be generated by a small mobile fraction of the added defects that are more readily annealed than the majority of the defects. After a room temperature annealing process, both the noise and resistivity returned nearly to their initial values. The temperature dependence of the noise after irradiation and partial annealing was consistent with the Dutta-Dimon-Horn thermal activation model. (Auth.)

  15. Correlation of Electronic and Geometric Structure in Mononuclear Copper(II) Superoxide Complexes

    Science.gov (United States)

    Ginsbach, Jake W.; Peterson, Ryan L.; Cowley, Ryan E.; Karlin, Kenneth D.; Solomon, Edward I.

    2013-01-01

    The geometry of mononuclear copper(II) superoxide complexes has been shown to determine their ground state where side-on bonding leads to a singlet ground state and end-on complexes have triplet ground states. In apparent contrast to this trend, the recently synthesized (HIPT3tren)CuII–O2•− (1) was proposed to have an end-on geometry and a singlet ground state. However, re-examination of 1 with resonance Raman (rR), magnetic circular dichroism (MCD), and 2H NMR spectroscopy indicates that 1 is in fact an end-on superoxide species with a triplet ground state that results from the single CuII–O2•− bonding interaction being weaker than the spin pairing energy. PMID:24164429

  16. Copper resistance determinants in bacteria.

    Science.gov (United States)

    Brown, N L; Rouch, D A; Lee, B T

    1992-01-01

    Copper is an essential trace element that is utilized in a number of oxygenases and electron transport proteins, but it is also a highly toxic heavy metal, against which all organisms must protect themselves. Known bacterial determinants of copper resistance are plasmid-encoded. The mechanisms which confer resistance must be integrated with the normal metabolism of copper. Different bacteria have adopted diverse strategies for copper resistance, and this review outlines what is known about bacterial copper resistance mechanisms and their genetic regulation.

  17. Biological versus chemical leaching of electronic waste for copper and gold recovery

    OpenAIRE

    Isildar , Arda

    2016-01-01

    The well-being of the society depends on a number of metals, including base metals, precious metals and increasingly rare earth elements (REE). The usage of these metals increased in numerous applications, including electrical and electronic equipment (EEE), and their interrupted supply is at stake. There is an increasing interest in the secondary sources of these metals, particularly waste electrical and electronic equipment (WEEE) in order to compensate their potential supply deficit. This ...

  18. Structural, optical and electronic properties of indium sulfide compositions under influence of copper impurity produced by chemical method

    Science.gov (United States)

    Esmaili, Parisa; Kangarlou, Haleh; Savaloni, Hadi; Ghorannevis, Mahmood

    Aqueous solutions with 70 °C and pH = 2.5 constant values were prepared from convenient chemical compounds to produce In2S3: Cu crystals and thin films. Crystal compositions were grown in this solution under special conditions. Micrographs showed amorphous In2S3 orange powder and transparent vitreous pieces of CuInS2 crystals. Indium sulfide films were produced using the same solution in CBD method, on the glass substrates at different [Cu/In] molar ratio concentrations. Cu+ ions by different concentration doped from copper chloride source into In2S3 films. The produced films were post-annealed at 400 °C for about 1 h. Their crystallography, phase transitions, element analysis and nanostructures were investigated by X-ray diffraction, SEM, EDAX and AFM analyses. β-In2S3 phase was dominant and by doping copper impurity, XRD results suggested the formation of CuInS2 compositions. Morphology of the films, nano-structures, grain shapes and hardness was changed. Optical reflectance was measured in the UV-VIS wavelength range by a spectrophotometer. Other optical properties and optical band gaps were calculated using Kramers-Kronig relations on reflectivity curves. Electronic properties were calculated by full potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT). In this approach, generalized gradient approximation (GGA) was used for the exchange-correlation potential calculation. Band gap structures, density of states and imaginary parts of dielectric function were calculated for In2S3: Cu compositions.

  19. Electron beam welding of copper lids. Status report up to 2001-12-31

    International Nuclear Information System (INIS)

    Claesson, Soeren; Ronneteg, Ulf

    2003-10-01

    The report describes a summary of achieved results from 21 lid welds and numerous test block welds, performed at SKB Canister Laboratory in Oskarshamn for the period 1999-02-12 to 2001-12-31. Good weld quality has been achieved and some welds fulfilled the preliminary interpretation criteria, but the weld process need to be further developed before process qualification. Many different parameter settings have been tested and the influence on the weld profile has been mapped and documented. Deformations of the canister after welding have been measured and found to be very small. The preliminary inspection methods of the weld quality works satisfactory for the need of the development of the weld process. The welding machine is a new design developed for welding of thick copper in reduced pressure and performs well, but suffers from teething problems, which has delayed the work with development of the weld process. The welding system needs to be further developed and improved to work more reliably in a production plant

  20. Electron beam welding of copper lids. Status report up to 2001-12-31

    Energy Technology Data Exchange (ETDEWEB)

    Claesson, Soeren; Ronneteg, Ulf

    2003-10-01

    The report describes a summary of achieved results from 21 lid welds and numerous test block welds, performed at SKB Canister Laboratory in Oskarshamn for the period 1999-02-12 to 2001-12-31. Good weld quality has been achieved and some welds fulfilled the preliminary interpretation criteria, but the weld process need to be further developed before process qualification. Many different parameter settings have been tested and the influence on the weld profile has been mapped and documented. Deformations of the canister after welding have been measured and found to be very small. The preliminary inspection methods of the weld quality works satisfactory for the need of the development of the weld process. The welding machine is a new design developed for welding of thick copper in reduced pressure and performs well, but suffers from teething problems, which has delayed the work with development of the weld process. The welding system needs to be further developed and improved to work more reliably in a production plant.

  1. Electron transfer activity of a de novo designed copper center in a three-helix bundle fold.

    Science.gov (United States)

    Plegaria, Jefferson S; Herrero, Christian; Quaranta, Annamaria; Pecoraro, Vincent L

    2016-05-01

    In this work, we characterized the intermolecular electron transfer (ET) properties of a de novo designed metallopeptide using laser-flash photolysis. α3D-CH3 is three helix bundle peptide that was designed to contain a copper ET site that is found in the β-barrel fold of native cupredoxins. The ET activity of Cuα3D-CH3 was determined using five different photosensitizers. By exhibiting a complete depletion of the photo-oxidant and the successive formation of a Cu(II) species at 400 nm, the transient and generated spectra demonstrated an ET transfer reaction between the photo-oxidant and Cu(I)α3D-CH3. This observation illustrated our success in integrating an ET center within a de novo designed scaffold. From the kinetic traces at 400 nm, first-order and bimolecular rate constants of 10(5) s(-1) and 10(8) M(-1) s(-1) were derived. Moreover, a Marcus equation analysis on the rate versus driving force study produced a reorganization energy of 1.1 eV, demonstrating that the helical fold of α3D requires further structural optimization to efficiently perform ET. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. In situ monitoring of flash-light sintering of copper nanoparticle ink for printed electronics.

    Science.gov (United States)

    Hwang, Hyun-Jun; Chung, Wan-Ho; Kim, Hak-Sung

    2012-12-07

    In this work, a flash-light sintering process for Cu nanoinks was studied. In order to precisely monitor the milliseconds flash-light sintering process, a real-time Wheatstone bridge electrical circuit and a high-rate data acquisition system were used. The effects of several flash-light irradiation conditions (irradiation energy, pulse number, on-time, and off-time) and the effects of the amount of poly(N-vinylpyrrolidone) in the Cu nanoink on the flash-light sintering process were investigated. The microstructures of the sintered Cu films were analyzed by scanning electron microscopy. To investigate the oxidation or reduction of the oxide-covered copper nanoparticles, a crystal phase analysis using x-ray diffraction was performed. In addition, the sheet resistance of Cu film was measured using a four-point probe method. From this study, it was found that the flash-light sintered Cu nanoink films have a conductivity of 72 Ωm/sq without any damage to the polyimide substrate. Similar nanoinks are expected to be widely used in printed and flexible electronics products in the near future.

  3. Direct measurement of the electron-phonon relaxation rate in thin copper films

    Energy Technology Data Exchange (ETDEWEB)

    Taskinen, L.J.; Karvonen, J.T.; Maasilta, I.J. [NanoScience Center, Department of Physics, P.O. Box 35, FIN-40014 University of Jyvaeskylae (Finland); Kivioja, J.M. [Low Temperature Laboratory, Helsinki University of Technology, P.O. Box 2200, 02015 HUT Helsinki (Finland)

    2004-11-01

    We have used normal metal-insulator-superconductor (NIS) tunnel junction pairs, known as SINIS structures, for ultrasensitive thermometry at sub-Kelvin temperatures. With the help of these thermometers, we have developed an ac-technique to measure the electron-phonon (e-p) scattering rate directly, without any other material or geometry dependent parameters, based on overheating the electron gas. The technique is based on Joule heating the electrons in the frequency range DC-10 MHz, and measuring the electron temperature in DC. Because of the nonlinearity of the electron-phonon coupling with respect to temperature, even the DC response will be affected, when the heating frequency reaches the natural cut-off determined by the e-p scattering rate. Results on thin Cu films show a T{sup 4} behavior for the scattering rate, in agreement with indirect measurement of similar samples and numerical modeling of the non-linear response. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Ab initio study of the structural, magnetic, and electronic properties of copper and silver clusters and their alloys with one palladium atom

    Directory of Open Access Journals (Sweden)

    S. J Hashemifar

    2015-01-01

    Full Text Available In this paper, the structural, magnetic, and electronic properties of two- to nine-atom copper and silver clusters and their alloys with one palladium atom are investigated by using full-potential all-electron density functional computations. After calculating minimized energy of several structural isomers of every nanocluster, it is argued that the small size nanoclusters (up to size of 6, ‎ prefer planar structures, while by increasing size a 2D-3D structural transformation is observed. The structural transformation of pure and copper-palladium clusters occurs in the size of seven and that of silver-palladium cluster in happens at the size of six. The calculated second difference and dissociation energies confirm that the two- and eight- atom pure clusters and three- and seven- atom alloyed clusters are magic clusters. The electronic and magnetic properties of stable isomers are calculated and considered after applying many body based GW correction.

  5. Trends in Geometric, Energetic, Electronic, and Magnetic Properties of Vanadium-Copper Clusters Cu n V with n = 1-12: Density Functional Calculations

    Science.gov (United States)

    Dong, Yan-Yun; Zhang, Cai-Yun; Wang, Bing-Qiang

    2017-12-01

    A systematic quantum chemical investigation on the geometric, energetic, electronic and magnetic properties of vanadium-copper nanoalloy clusters ( n = 1-12) is performed by using BPW91/LanL2DZ calculations. The calculated results show that the structural evolution of Cu n V clusters favors a compact and icosahedral growth pattern and V atom favors occupying the most highly coordinated position. Energetic properties show that doping of one V atom contributes to strengthening the stability of the copper clusters with the growth of the clusters. The stacking mode of clusters apparently has a more important effect on the clusters stability than the electronic structure. However, electronic structures have some contribution to the stability of Cu n V clusters as well. The electronic properties of Cu n V are analyzed through vertical ionization potential (VIP), vertical electron affinity (VEA) and chemical hardness (η). The magnetism calculations show that when doping V atom in copper clusters, the cluster system generate a very large magnetic moment and its contribution mainly comes from the 3 d orbital of doping-V atom.

  6. Characterizing the geometric and electronic structure of defects in the "29" copper surface oxide

    Science.gov (United States)

    Therrien, Andrew J.; Hensley, Alyssa J. R.; Zhang, Renqin; Pronschinske, Alex; Marcinkowski, Matthew D.; McEwen, Jean-Sabin; Sykes, E. Charles H.

    2017-12-01

    The geometric and electronic structural characterization of thin film metal oxides is of fundamental importance to many fields such as catalysis, photovoltaics, and electrochemistry. Surface defects are also well known to impact a material's performance in any such applications. Here, we focus on the "29" oxide Cu2O/Cu(111) surface and we observe two common structural defects which we characterize using scanning tunneling microscopy/spectroscopy and density functional theory. The defects are proposed to be O vacancies and Cu adatoms, which both show unique topographic and spectroscopic signatures. The spatially resolved electronic and charge state effects of the defects are investigated, and implications for their reactivity are given.

  7. Copper-Containing Nitrite Reductase Employing Proton-Coupled Spin-Exchanged Electron-Transfer and Multiproton Synchronized Transfer to Reduce Nitrite.

    Science.gov (United States)

    Qin, Xin; Deng, Li; Hu, Caihong; Li, Li; Chen, Xiaohua

    2017-10-20

    The possible catalytic mechanism of the reduction of nitrite by copper-containing nitrite reductases (CuNiRs) is examined by using the M06 function according to two copper models, which include type-one copper (T1Cu) and type-two copper (T2Cu) sites. Examinations confirm that the protonation of two residues, His255 and Asp98, near the T2Cu site, can modulate the redox states of T1Cu and T2Cu, but cannot directly cause electron transfer from T1Cu to T2Cu. The electron hole remains at the T2Cu site when only one residue, His255 or Asp98, is protonated. However, the hole resides at the T1Cu site when both His255 and Asp98 are protonated. Then, the first protonation of nitrite takes place through indirect proton transfer from protonated His255 through the bridging H 2 O and Asp98 with three protons moving together, which cannot cause the cleavage of the HO-NO bond. Subsequently, the substrate is required to obtain another proton from reprotonated His255 through the bridging H 2 O. The reprotonation of nitrite induces the generation of nitric oxide (NO) and H 2 O at the T2Cu site through a special double-proton-coupled spin-exchanged electron-transfer mechanism with indirect proton transfer from His255 to the substrate, a beta-electron of T2Cu I shift to the NO cation, and the remaining alpha-electron changing spin direction at the same time. These results may provide useful information to better understand detailed proton-/electron-transfer reactions for the catalytic processes of CuNiR. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Analysis of electronic parameters of nanostructure copper doped cadmium oxide/p-silicon heterojunction

    Energy Technology Data Exchange (ETDEWEB)

    Karatas, Suekrue, E-mail: skaratas@ksu.edu.tr [Department of Physics, Faculty of Science, Suetcue Imam University, Karamanmaras (Turkey); Yakuphanoglu, Fahrettin [Department of Physics, Faculty of Science, Firat University, Elazig (Turkey)

    2012-10-05

    Highlights: Black-Right-Pointing-Pointer The copper doped cadmium oxide (CdO) heterojunction diodes were fabricated by sol-gel method. Black-Right-Pointing-Pointer The electrical properties of Cu doped CdO/p-Si heterojunction diode have been investigated. Black-Right-Pointing-Pointer A strong effect of the Cu-doped content on the I-V characteristics of the diodes was found. Black-Right-Pointing-Pointer It is evaluated that the electrical performance of the CdO/p-Si diode can be controlled by Cu doped. - Abstract: The nanostructure Cu-doped CdO thin film was grown on p-type silicon substrate by sol-gel method. An Al/Cu doped CdO/p-Si heterojunction diode was fabricated. The values of ideality factor and barrier height for the Al/n-type CdO/p-Si heterojunction were obtained as 5.99 and 0.69 eV, respectively. A modified Norde function combined with conventional forward I-V method was used to extract the junction parameters including the ideality factor, barrier height and series resistance. Norde function was compared with the Cheung functions and it is seen that there is a good agreement with both method for the series resistance values. Furthermore, the interface state density (N{sub SS}) as a function of energy distribution (E{sub SS} - E{sub V}) was extracted from the forward-bias I-V measurements by taking into account the bias dependence of the effective barrier height and series resistance.

  9. Doping the Copper-Oxygen Planes with Electrons: The View with Photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Armitage, Norman P.

    2002-03-07

    The undoped parent compounds of high-temperature cuprate superconductors are known to be antiferromagnetic Mott insulators. As the CuO{sub 2} planes are doped with charge carriers, the antiferromagnetic phase subsides and superconductivity emerges. The symmetry, or the lack thereof, between doping with electrons (n-type) or holes (p-type) has important theoretical implications as most models implicitly assume symmetry. However, most of what we know about these superconductors comes from experiments performed on p-type materials. The much fewer number of measurements from n-type compounds suggest that there may be both commonalities and differences between the two sides of the phase diagram. This issue of electron/hole symmetry has not been seriously discussed, perhaps, because the experimental database of n-type results is very limited.

  10. Dislocation Climb Sources Activated by 1 MeV Electron Irradiation of Copper-Nickel Alloys

    DEFF Research Database (Denmark)

    Barlow, P.; Leffers, Torben

    1977-01-01

    of irradiation temperatures corresponding to the highest source densities is approximately 350°–500°C. The climb sources are not related to any pre-existing dislocations resolved in the microscope. The sources emit three types of loop: ‘rectangular’ loops with a100 Burgers vector and {100} habit plane, normal......Climb sources emitting dislocation loops are observed in Cu-Ni alloys during irradiation with 1 MeV electrons in a high voltage electron microscope. High source densities are found in alloys containing 5, 10 and 20% Ni, but sources are also observed in alloys containing 1 and 2% Ni. The range...... prismatic loops with Burgers vector a/2110, and Frank loops. There is no significant difference between the apparent activation energy for growth of the three types of loops. The source points are suggested to be submicroscopic nickel precipitates-with reference to the existing evidence that...

  11. Effects of filler wire on residual stress in electron beam welded QCr0.8 copper alloy to 304 stainless steel joints

    International Nuclear Information System (INIS)

    Zhang, Bing-Gang; Zhao, Jian; Li, Xiao-Peng; Chen, Guo-Qing

    2015-01-01

    The electron beam welding (EBW) of 304 stainless steel to QCr0.8 copper alloy with or without copper filler wire was studied in detail. The temperature fields and magnitude and distribution of stress fields in the joints during the welding process were numerically simulated using finite element method. The temperature cycles and residual stresses were also experimentally measured by thermometric and hole-drilling methods, respectively. The accuracy of the modeling procedure was verified by the good agreement between the calculated results and experimental data. The temperature distribution in the joint was found to be asymmetric along the center of weld. In particular, the temperature in the copper alloy plate is much higher than that in the 304 SS plate owing to the great difference in thermal conductivity between the two materials. The peak three-dimensional residual stresses all appeared at the interface between the copper and steel in the two different joints. Furthermore, the weld was subjected to tensile stress. The longitudinal residual stress, generally the most harmful to the integrity of the structure among the stress components in EBW with filler wire (EBFW), was 53 MPa lower than that of autogenous EBW (AEBW), and the through-thickness residual stress was 12 MPa lower. The transverse residual stress of EBFW was 44 MPa higher than that of AEBW. However, analysis of the von Mises stress showed that the EBFW process effectively reduced the extent of the high residual stress region in the weld location and the magnitude of the residual stresses in the copper side compared with those of the AEBW joint. - Highlights: • Copper and steel was welded by electron beam welding with copper filler wire. • The copper wire fed into gap can reduce the peak value of residual stress. • The peak value of longitudinal stress can be reduced 53 MPa by the filler wire. • The range of nov Mises stress in the weld could be reduced by the wire

  12. Quantifying height of ultraprecisely machined steps on oxygen-free electronic copper disc using Fourier-domain short coherence interferometry

    CERN Document Server

    Montonen, Risto; Hæggström, Edward; Österberg, Kenneth

    2016-01-01

    The internal shape and alignment of accelerator discs is crucial for efficient collider operation at the future compact linear collider (CLIC). We applied a calibrated custom-made Fourier-domain short coherence interferometer to measure the height of 40 and 60μm60  μm ultraprecisely turned steps (surface roughness Ra≤25nmRa≤25  nm, flatness ≤2μm≤2  μm) on an oxygen-free electronic copper disc. The step heights were quantified to be (39.6±2.6)μm(39.6±2.6)  μm and (59.0±2.3)μm(59.0±2.3)  μm. The uncertainties are quoted at 95% confidence level and include contributions from calibration, refractive index of air, cosine error, surface roughness, and thermal expansion in comparison to standard temperature of 20°C. The results were verified by measuring the same steps using a commercial white light interferometer Veeco—NT3300. Our instrument can ensure that the accelerator discs of the CLIC are aligned within the tolerance required for efficient collider operation.

  13. Highly adhesive and high fatigue-resistant copper/PET flexible electronic substrates

    Science.gov (United States)

    Park, Sang Jin; Ko, Tae-Jun; Yoon, Juil; Moon, Myoung-Woon; Oh, Kyu Hwan; Han, Jun Hyun

    2018-01-01

    A voidless Cu/PET substrate is fabricated by producing a superhydrophilic PET surface comprised of nanostructures with large width and height and then by Cu electroless plating. Effect of PET surface nanostructure size on the failure mechanism of the Cu/PET substrate is studied. The fabricated Cu/PET substrate exhibits a maximum peel strength of 1300 N m-1 without using an interlayer, and virtually no increase in electrical resistivity under the extreme cyclic bending condition of 1 mm curvature radius after 300 k cycles. The authors find that there is an optimum nanostructure size for the highest Cu/PET adhesion strength, and the failure mechanism of the Cu/PET flexible substrate depends on the PET surface nanostructure size. Thus, this work presents the possibility to produce flexible metal/polymer electronic substrates that have excellent interfacial adhesion between the metal and polymer and high fatigue resistance against repeated bending. Such metal/polymer substrates provides new design opportunities for wearable electronic devices that can withstand harsh environments and have extended lifetimes.

  14. The influence of defect agglomerates on the recovery of Frenkel defects in copper after electron irradiation at 4.7 K

    International Nuclear Information System (INIS)

    Wienhold, P.

    1977-02-01

    Specimens of extremely pure copper have been doped with defect agglomerates of density rhosub(d) by particle irradiation and annealing and subsequently provided with isolated Frenkel defects (density Δrho 0 ) as testing defects by electron irradiation at 4.7 K. By means of isochrone annealing, the recuperation of the testing defects in the presence of the agglomerate doping in comparison with undoped specimens was observed. (orig./HPOE) [de

  15. The Stepwise Protonation and Electron-Transfer Reduction of a Primary Copper-Dioxygen Adduct

    Science.gov (United States)

    Peterson, Ryan L.; Ginsbach, Jake W.; Cowley, Ryan E.; Qayyum, Munzarin F.; Himes, Richard A.; Siegler, Maxime A.; Moore, Cathy D.; Hedman, Britt; Hodgson, Keith O.; Fukuzumi, Shunichi; Solomon, Edward I.; Karlin, Kenneth D.

    2013-01-01

    The protonation-reduction of a dioxygen adduct with [LCuI][B(C6F5)4], cupric superoxo complex [LCuII(O2•−)]+ (1), (L=TMG3tren(1,1,1-tris[2-[N2-(1,1,3,3-tetramethylguanidino)]ethyl]amine)), has been investigated. Trifluoroacetic acid (HOAcF) reversibly associates with the superoxo ligand in ([LCuII(O2•−)]+) in a 1:1 adduct [LCuII(O2•−)(HOAcF)]+ (2), as characterized by UV-visible, resonance Raman (rR), nuclear magnetic resonance (NMR) and X-ray absorption (XAS) spectroscopies, along with density functional theory (DFT) calculations. Chemical studies reveal that for the binding of HOAcF with 1 to give 2, Keq = 1.2×105 M−1 (−130 °C) and ΔH° = − 6.9(7) kcal/mol, ΔS° = − 26(4) cal/mol•K). Vibrational (rR) data reveal a significant increase (29 cm−1) in νO-O (= 1149 cm−1) compared to that known for [LCuII(O2•−)]+ (1). Along with results obtained from XAS and DFT calculations, hydrogen bonding of HOAcF to a superoxo O-atom in 2 is established. NMR spectroscopy of 2 at −120 °C in 2-methyltetrahydrofuran are also consistent with 1/HOAcF = 1:1 formulation 2 and that this complex possesses a triplet (S = 1) ground state electronic configuration, as previously determined for 1. The pre-equilibrium acid association to 1 is followed by outer-sphere electron-transfer reduction of 2 by decamethylferrocene (Me10Fc) or octamethylferrocene (Me8Fc), leading to the products H2O2, the corresponding ferrocenium salt and [LCuII(OAcF)]+. Second-order rate constants for electron transfer (ket) were determined to be 1365 M−1 s−1 (Me10Fc) and 225 M−1 s−1 (Me8Fc) at −80 °C. The (bio)chemical relevance of the proton-triggered reduction of the metal-bound dioxygen-derived fragment is discussed. PMID:24164682

  16. Electron paramagnetic resonance spectra of copper ion doped lithium barium borate glasses

    Science.gov (United States)

    Bhogi, Ashok; Kumar, R. Vijaya; Kistaiah, P.

    2017-05-01

    Glasses with composition 25Li2O-15BaO- (60-x) B2O3- x CuO (where x=0, 0.2, 0.4, 0.6, 0.8 and 1.0 mol %) were prepared by the conventional melt quenching technique. These glasses were characterized using X-ray diffraction (XRD). Electron paramagnetic resonance spectra of prepared glasses have been studied. The EPR spectrum consists of four hyperfine lines characteristic of Cu2+ ions. From the observed spectra the spin-Hamiltonian parameters have been evaluated. The values of spin-Hamiltonian parameters indicate that the Cu2+ ions in the studied glasses were present in octahedral coordination with a strong tetragonal distortion. The molecular orbital coefficients have been evaluated.

  17. Study of planar defects associated to martensite transformation in copper alloys by transmission electron microscopy

    International Nuclear Information System (INIS)

    Condo, A.M.

    1997-01-01

    In this work the planar faults in non-compact planes (non-basal faults) in the 2H and 18R martensitic phases in Cu-Zn-Al alloys are analyzed. The study was carried out using transmission electron microscopy (TEM) combining the two-beam condition technique, high resolution transmission electron microscopy (HRTEM) and computer simulated images. The displacement vectors of the faults were determined. It was found that these vectors were different from those of the basal faults, even though the faults are connected. One single class of non-basal faults, named F 1 , was observed in the 2H phase, whereas two different classes were found in the 18R phase, named F o and F x . In the latter phase non-basal faults made up of different segments of F o and F x faults were observed (composed faults). The Burgers vectors of the partial dislocations at the edges of the non-basal faults were determined in both phases. Additionally, the Burgers vectors of the intermediate dislocations found between the different segments of the composed faults in the 18R phase were determined. It was verified that there exist two types of dislocations with Burgers vectors that differ in approximately 1/3 [100]. It was found that the presence of a particular dislocation type depends on the arrangement between the non-basal fault and the basal fault that originates the dislocation. The internal structure of the non-basal faults in the 18R phase was studied with HRTEM. It was observed that the shift of the crystal planes due to the presence of the faults occurs in a region of a finite extension of about 1.5 nm. It was also observed that in this region the crystal planes appear rotated and lose the characteristic corrugation they have in the 18R structure. As a consequence of this, new translation vectors appear in the defect; this fact could be reflected in new plastic deformation systems. The rotation of the crystal planes in the non-basal faulted area of the 18R phase was compared with the rotation

  18. Electronic properties and morphology of copper oxide/n-type silicon heterostructures

    Science.gov (United States)

    Lindberg, P. F.; Gorantla, S. M.; Gunnæs, A. E.; Svensson, B. G.; Monakhov, E. V.

    2017-08-01

    Silicon-based tandem heterojunction solar cells utilizing cuprous oxide (Cu2O) as the top absorber layer show promise for high-efficiency conversion and low production cost. In the present study, single phase Cu2O films have been realized on n-type Si substrates by reactive magnetron sputtering at 400 °C. The obtained Cu2O/Si heterostructures have subsequently been heat treated at temperatures in the 400-700 °C range in Ar flow and extensively characterized by x-ray diffraction (XRD) measurements, transmission electron microscopy (TEM) imaging and electrical techniques. The Cu2O/Si heterojunction exhibits a current rectification of ~5 orders of magnitude between forward and reverse bias voltages. High resolution cross-sectional TEM-images show the presence of a ~2 nm thick interfacial SiO2 layer between Cu2O and the Si substrate. Heat treatments below 550 °C result in gradual improvement of crystallinity, indicated by XRD. At and above 550 °C, partial phase transition to cupric oxide (CuO) occurs followed by a complete transition at 700 °C. No increase or decrease of the SiO2 layer is observed after the heat treatment at 550 °C. Finally, a thin Cu-silicide layer (Cu3Si) emerges below the SiO2 layer upon annealing at 550 °C. This silicide layer influences the lateral current and voltage distributions, as evidenced by an increasing effective area of the heterojunction diodes.

  19. 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.

  20. Cu2+ in Keggin anion - Influence of copper position on electronic structure/redox properties of heteropolyacids. DFT cluster model study

    Science.gov (United States)

    Tokarz-Sobieraj, Renata; Niemiec, Piotr

    2017-05-01

    Heteropolyacids systems (HPAs) exhibit a wide range of molecular sizes, compositions and architectures. Modification of those parameters leads to the creation of a structure that presents diverse chemical and catalytic features. In this paper, the theoretical description of electronic structure of tungsten and molybdenum heteropolyacids modified by copper Cu2+ ion (Cu-HPA) has been presented. The obtained results showed that the Cu2+ cation introduced into the Keggin anion, into the position of the central ion or addenda atom(s), influences the acid-base properties of the active centers that are present in the system. In addition, the impact of copper ions on the density of states and character of frontier orbitals has been presented.

  1. Enhanced Catalytic Four-Electron Dioxygen (O2) and Two-Electron Hydrogen Peroxide (H2O2) Reduction with a Copper(II) Complex Possessing a Pendant Ligand Pivalamido Group

    Science.gov (United States)

    Kakuda, Saya; Peterson, Ryan L.; Ohkubo, Kei; Karlin, Kenneth D.; Fukuzumi, Shunichi

    2013-01-01

    A copper complex, [(PV-tmpa)CuII](ClO4)2 (1) [PV-tmpa = bis(pyrid-2-ylmethyl){[6-(pivalamido)pyrid-2-yl]methyl}-amine], acts as a more efficient catalyst for the four-electron reduction of O2 by decamethylferrocene (Fc*) in the presence of trifluoroacetic acid (CF3COOH) in acetone as compared with the corresponding copper complex without a pivalamido group, [(tmpa)CuII](ClO4)2 (2) (tmpa = tris(2-pyridylmethyl)amine). The rate constant (kobs) of formation of decamethylferrocenium ion (Fc*+) in the catalytic four-electron reduction of O2 by Fc* in the presence large excess CF3COOH and O2 obeyed first-order kinetics. The kobs value was proportional to the catalyst concentrations, 1 or 2 whereas the kobs value remained constant irrespective of the concentrations of CF3COOH or O2. This indicates that electron transfer from Fc* to 1 or 2 is the rate-determining step in the catalytic cycle of the four-electron reduction of O2 by Fc* in the presence of CF3COOH. The second-order catalytic rate constant (kcat) for 1 is four times larger than the corresponding value determined for 2. Separate studies reveal that electron transfer from Fc* to the CuII complex is the rate-determining step in the case of PV-tmpa ligand, because the carbonyl oxygen of the pivalamido group inhibits the coordination of CF3COO− to copper, in direct contrast to the case for the tmpa ligand-complex. 1 is also an excellent catalyst for the two-electron two-proton reduction of H2O2 to water, and is also more efficient than is 2. For both complexes, reaction rates are greater than for overall four-electron O2-reduction to water, an important asset in the design of catalysts for the latter. PMID:23509853

  2. The effect of hot bending and thermal ageing on creep and microstructure evolution in thick-walled P92 steel pipe

    Czech Academy of Sciences Publication Activity Database

    Sklenička, Václav; Kuchařová, Květa; Král, Petr; Kvapilová, Marie; Svobodová, M.; Čmakal, J.

    2015-01-01

    Roč. 644, SEP (2015), s. 297-309 ISSN 0921-5093 R&D Projects: GA TA ČR TA02010260; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : Steel * Thermomechanical processing * Mechanical characterization * Electron microscopy * Ageing Subject RIV: JG - Metallurgy Impact factor: 2.647, year: 2015

  3. Protection by high velocity thermal spraying coatings on thick walled permanent and interim store components for the diminution of repairs, corrosion and costs 'SHARK'. Overview at the end of the project

    International Nuclear Information System (INIS)

    Behrens, Sabine; Hassel, Thomas; Bach, Friedrich-Wilhelm

    2012-01-01

    The corrosion protection of the internal space of thick-walled interim and permanent storage facility components, such as Castor copyright containers, are ensured nowadays by a galvanic nickel layer. The method has proved itself and protects the base material of the containers at the underwater loading in the Nuclear power station from a corrosive attack. Although, the galvanic nickel plating is a relatively time consuming method, it lasts for several days for each container, and is with a layer thickness of 1,000 μm also expensive. To develop an alternative, faster and more economical method, a BMBF research project named - 'SHARK - protection by high velocity thermal spraying layers on thick-walled permanent and interim store components for the diminution of repairs, corrosion and costs' in cooperation between Siempelkamp Nukleartechnik GmbH and the Institute of Materials Science of the Leibniz University of Hanover was established to investigate the suitability of the high velocity oxy fuel spraying technology (HVOF) for the corrosion protective coating of thickwalled interim and permanent storage facility components. Since the permanent storage depot components are manufactured from cast iron with globular graphite, this material was exclusively used as a base material in this project. The evaluation of the economical features of the application of different nickel base spraying materials on cast iron substratum was in focus, as well as the scientific characterization of the coating systems with regard to the corrosion protective properties. Furthermore, the feasibility of the transfer of the laboratory results on a large industrial setup as well as a general suitability of the coating process for a required repair procedure was to be investigated. The preliminary examination program identified chromium containing spraying materials as successful. Results of the preliminary examination program have been used for investigations with the CASOIK demonstration

  4. The electronic spectra and the structures of the individual copper(II) chloride and bromide complexes in acetonitrile according to steady-state absorption spectroscopy and DFT/TD-DFT calculations

    Science.gov (United States)

    Olshin, Pavel K.; Myasnikova, Olesya S.; Kashina, Maria V.; Gorbunov, Artem O.; Bogachev, Nikita A.; Kompanets, Viktor O.; Chekalin, Sergey V.; Pulkin, Sergey A.; Kochemirovsky, Vladimir A.; Skripkin, Mikhail Yu.; Mereshchenko, Andrey S.

    2018-03-01

    The results of spectrophotometric study and quantum chemical calculations for copper(II) chloro- and bromocomplexes in acetonitrile are reported. Electronic spectra of the individual copper(II) halide complexes were obtained in a wide spectral range 200-2200 nm. Stability constants of the individual copper(II) halide complexes in acetonitrile were calculated: log β1 = 8.5, log β2 = 15.6, log β3 = 22.5, log β4 = 25.7 for [CuCln]2-n and log β1 = 17.0, log β2 = 24.6, log β3 = 28.1, log β4 = 30.4 for [CuBrn]2-n. Structures of the studied complexes were optimized and electronic spectra were simulated using DFT and TD-DFT methodologies, respectively. According to the calculations, the more is the number of halide ligands the less is coordination number of copper ion.

  5. Heat-Induced, Pressure-Induced and Centrifugal-Force-Induced Exact Axisymmetric Thermo-Mechanical Analyses in a Thick-Walled Spherical Vessel, an Infinite Cylindrical Vessel, and a Uniform Disk Made of an Isotropic and Homogeneous Material

    Directory of Open Access Journals (Sweden)

    Vebil Yıldırım

    2017-07-01

    Full Text Available Heat-induced, pressure-induced, and centrifugal force-induced axisymmetric exact deformation and stresses in a thick-walled spherical vessel, a cylindrical vessel, and a uniform disk are all determined analytically at a specified constant surface temperature and at a constant angular velocity. The inner and outer pressures are both included in the formulation of annular structures made of an isotropic and homogeneous linear elastic material. Governing equations in the form of Euler-Cauchy differential equation with constant coefficients are solved and results are presented in compact forms. For disks, three different boundary conditions are taken into account to consider mechanical engineering applications. The present study is also peppered with numerical results in graphical forms.

  6. Fluorescence and electron paramagnetic resonance studies of norfloxacin and N-donor mixed-ligand ternary copper(II) complexes: Stability and interaction with SDS micelles

    Science.gov (United States)

    Vignoli Muniz, Gabriel S.; Incio, Jimmy Llontop; Alves, Odivaldo C.; Krambrock, Klaus; Teixeira, Letícia R.; Louro, Sonia R. W.

    2018-01-01

    The stability of ternary copper(II) complexes of a heterocyclic ligand, L (L being 2,2‧-bipyridine (bipy) or 1,10-phenanthroline (phen)) and the fluorescent antibacterial agent norfloxacin (NFX) as the second ligand was studied at pH 7.4 and different ionic strengths. Fluorescence quenching upon titration of NFX with the binary complexes allowed to obtain stability constants for NFX binding, Kb, as a function of ionic strength. The Kb values vary by more than two orders of magnitude when buffer concentration varies from 0.5 to 100 mM. It was observed that previously synthesized ternary complexes dissociate in buffer according with the obtained stability constants. This shows that equimolar solutions of NFX and binary complexes are equivalent to solutions of synthesized ternary complexes. The interaction of the ternary copper complexes with anionic SDS (sodium dodecyl sulfate) micelles was studied by fluorescence and electron paramagnetic resonance (EPR). Titration of NFX-loaded SDS micelles with the complexes Cu:L allowed to determine the stability constants inside the micelles. Fluorescence quenching demonstrated that SDS micelles increase the stability constants by factors around 50. EPR spectra gave details of the copper(II) local environment, and demonstrated that the structure of the ternary complexes inside SDS micelles is different from that in buffer. Mononuclear ternary complexes formed inside the micelles, while in buffer most ternary complexes are binuclear. The results show that anionic membrane interfaces increase formation of copper fluoroquinolone complexes, which can influence bioavailability, membrane diffusion, and mechanism of action of the antibiotics.

  7. Electron Injection from Copper Diimine Sensitizers into TiO 2 : Structural Effects and Their Implications for Solar Energy Conversion Devices

    Energy Technology Data Exchange (ETDEWEB)

    Mara, Michael W. [Department; Bowman, David N. [Department; Buyukcakir, Onur [Graduate; Shelby, Megan L. [Department; Haldrup, Kristoffer [Centre; Huang, Jier; Harpham, Michael R.; Stickrath, Andrew B.; Zhang, Xiaoyi; Stoddart, J. Fraser [Department; Coskun, Ali [Graduate; Jakubikova, Elena [Department; Chen, Lin X. [Department

    2015-07-21

    Copper(I) diimine complexes have emerged as low cost replacements for ruthenium complexes as light sensitizers and electron donors, but their shorter metal-to-ligand-charge-transfer (MLCT) states lifetimes and lability of transient Cu(II) species impede their intended functions. Two carboxylated Cu(I) bis-2,9-diphenylphenanthroline (dpp) complexes [Cu(I)(dpp-O(CH2CH2O)(5))(dpp-(COOH)(2))](+) and [Cu(I)(dpp-O(CH2CH2O)(5))(dpp-(F-COOH)(2))](+) (F = tolyl) with different linker lengths were synthesized in which the MLCT-state solvent quenching pathways are effectively blocked, the lifetime of the singlet MLCT state is prolonged, and the transient Cu(II) ligands are stabilized. Aiming at understanding the mechanisms of structural influence to the interfacial charge transfer in the dye-sensitized solar cell mimics, electronic and geometric structures as well as dynamics for the MLCT state of these complexes and their hybrid with TiO2 nanoparticles were investigated using optical transient spectroscopy, X-ray transient absorption spectroscopy, time-dependent density functional theory, and quantum dynamics simulations. The combined results show that these complexes exhibit strong absorption throughout the visible spectrum due to the severely flattened ground state, and a long-lived charge-separated Cu(II) has been achieved via ultrafast electron injection (<300 fs) from the 1MLCT state into TiO2 nanoparticles. The results also indicate that the TiO2-phen distance in these systems does not have significant effect on the efficiency of the interfacial electron-transfer process. The mechanisms for electron transfer in these systems are discussed and used to develop new strategies in optimizing copper(I) diimine complexes in solar energy conversion devices.

  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. Lewis Acid-Induced Change from Four- to Two-Electron Reduction of Dioxygen Catalyzed by Copper Complexes Using Scandium Triflate

    Science.gov (United States)

    Kakuda, Saya; Rolle, Clarence; Ohkubo, Kei; Siegler, Maxime A.; Karlin, Kenneth D.; Fukuzumi, Shunichi

    2015-01-01

    Mononuclear copper complexes, [(tmpa)CuII(CH3CN)](ClO4)2 (1, tmpa = tris(2-pyridylmethyl)amine) and [(BzQ)CuII(H2O)2](ClO4)2 (2, BzQ = bis(2-quinolinylmethyl)benzylamine)], act as efficient catalysts for the selective two-electron reduction of O2 by ferrocene derivatives in the presence of scandium triflate (Sc(OTf)3), in acetone, whereas 1 catalyzes the four-electron reduction of O2 by the same reductant in the presence of Brønsted acids such as triflic acid. Following formation of the peroxo-bridged dicopper(II) complex [(tmpa)CuII(O2)CuII(tmpa)]2+, the two-electron reduced product of O2 with Sc3+ is observed to be scandium peroxide ([Sc3+(O22−)]+). In the presence of three equiv of hexamethylphosphoric triamide (HMPA), [Sc3+(O22−)]+ was oxidized by [Fe(bpy)3]3+ (bpy = 2,2′-bipyridine) to the known superoxide species [(HMPA)3Sc3+(O2•−)]2+ as detected by EPR spectroscopy. A kinetic study revealed that the rate-determining step of the catalytic cycle for the two-electron reduction of O2 with 1 is electron transfer from Fc* to 1 to give a cuprous complex which is highly reactive toward O2, whereas the rate-determining step with 2 is changed to the reaction of the cuprous complex with O2 following electron transfer from ferrocene derivatives to 2. The explanation for the change in catalytic O2-reaction stoichiometry from four-electron with Brønsted acids to two-electron reduction in the presence of Sc3+ and also for the change in the rate-determining step is clarified based on a kinetics interrogation of the overall catalytic cycle as well as each step of the catalytic cycle with study of the observed effects of Sc3+ on copper-oxygen intermediates. PMID:25659416

  10. Alterations in mitochondrial electron transport system activity in response to warm acclimation, hypoxia-reoxygenation and copper in rainbow trout, Oncorhynchus mykiss

    International Nuclear Information System (INIS)

    Sappal, Ravinder; MacDougald, Michelle; Fast, Mark; Stevens, Don; Kibenge, Fred; Siah, Ahmed; Kamunde, Collins

    2015-01-01

    Highlights: • Sequential inhibition and activation allows assessment of multiple segments of the electron transport system. • Warm acclimation and hypoxia-reoxygenation have global effects on the electron transport system. • Warm acclimation and hypoxia-reoxygenation sensitize the electron transport system to copper. • Thermal stress, hypoxia-reoxygenation and copper act additively to impair mitochondrial function. - Abstract: Fish expend significant amounts of energy to handle the numerous potentially stressful biotic and abiotic factors that they commonly encounter in aquatic environments. This universal requirement for energy singularizes mitochondria, the primary cellular energy transformers, as fundamental drivers of responses to environmental change. Our study probed the interacting effects of thermal stress, hypoxia-reoxygenation (HRO) and copper (Cu) exposure in rainbow trout to test the prediction that they act jointly to impair mitochondrial function. Rainbow trout were acclimated to 11 (controls) or 20 °C for 2 months. Liver mitochondria were then isolated and their responses in vitro to Cu (0–20 μM) without and with HRO were assessed. Sequential inhibition and activation of mitochondrial electron transport system (ETS) enzyme complexes permitted the measurement of respiratory activities supported by complex I–IV (CI–IV) in one run. The results showed that warm acclimation reduced fish and liver weights but increased mitochondrial protein indicating impairment of energy metabolism, increased synthesis of defense proteins and/or reduced liver water content. Whereas acute rise (11 → 20 °C) in temperature increased mitochondrial oxidation rates supported by CI–IV, warm acclimation reduced the maximal (state 3) and increased the basal (state 4) respiration leading to global uncoupling of oxidative phosphorylation (OXPHOS). HRO profoundly inhibited both maximal and basal respiration rates supported by CI–IV, reduced RCR for all except

  11. Alterations in mitochondrial electron transport system activity in response to warm acclimation, hypoxia-reoxygenation and copper in rainbow trout, Oncorhynchus mykiss

    Energy Technology Data Exchange (ETDEWEB)

    Sappal, Ravinder [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); MacDougald, Michelle [Faculty of Medicine, Memorial University of Newfoundland, Health Sciences Centre, Prince Philip Drive, St. John’s, NL, A1B 3V6 (Canada); Fast, Mark [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Stevens, Don [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Kibenge, Fred [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Siah, Ahmed [British Columbia Centre for Aquatic Health Sciences, 871A Island Highway, Campbell River, BC, V9W 2C2 (Canada); Kamunde, Collins, E-mail: ckamunde@upei.ca [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada)

    2015-08-15

    Highlights: • Sequential inhibition and activation allows assessment of multiple segments of the electron transport system. • Warm acclimation and hypoxia-reoxygenation have global effects on the electron transport system. • Warm acclimation and hypoxia-reoxygenation sensitize the electron transport system to copper. • Thermal stress, hypoxia-reoxygenation and copper act additively to impair mitochondrial function. - Abstract: Fish expend significant amounts of energy to handle the numerous potentially stressful biotic and abiotic factors that they commonly encounter in aquatic environments. This universal requirement for energy singularizes mitochondria, the primary cellular energy transformers, as fundamental drivers of responses to environmental change. Our study probed the interacting effects of thermal stress, hypoxia-reoxygenation (HRO) and copper (Cu) exposure in rainbow trout to test the prediction that they act jointly to impair mitochondrial function. Rainbow trout were acclimated to 11 (controls) or 20 °C for 2 months. Liver mitochondria were then isolated and their responses in vitro to Cu (0–20 μM) without and with HRO were assessed. Sequential inhibition and activation of mitochondrial electron transport system (ETS) enzyme complexes permitted the measurement of respiratory activities supported by complex I–IV (CI–IV) in one run. The results showed that warm acclimation reduced fish and liver weights but increased mitochondrial protein indicating impairment of energy metabolism, increased synthesis of defense proteins and/or reduced liver water content. Whereas acute rise (11 → 20 °C) in temperature increased mitochondrial oxidation rates supported by CI–IV, warm acclimation reduced the maximal (state 3) and increased the basal (state 4) respiration leading to global uncoupling of oxidative phosphorylation (OXPHOS). HRO profoundly inhibited both maximal and basal respiration rates supported by CI–IV, reduced RCR for all except

  12. One electron reduced square planar bis(benzene-1,2-dithiolato) copper dianionic complex and redox switch by O2/HO(-).

    Science.gov (United States)

    Maiti, Biplab K; Maia, Luisa B; Pal, Kuntal; Pakhira, Bholanath; Avilés, Teresa; Moura, Isabel; Pauleta, Sofia R; Nuñez, José L; Rizzi, Alberto C; Brondino, Carlos D; Sarkar, Sabyasachi; Moura, José J G

    2014-12-15

    The complex [Ph4P]2[Cu(bdt)2] (1(red)) was synthesized by the reaction of [Ph4P]2[S2MoS2CuCl] with H2bdt (bdt = benzene-1,2-dithiolate) in basic medium. 1(red) is highly susceptible toward dioxygen, affording the one electron oxidized diamagnetic compound [Ph4P][Cu(bdt)2] (1(ox)). The interconversion between these two oxidation states can be switched by addition of O2 or base (Et4NOH = tetraethylammonium hydroxide), as demonstrated by cyclic voltammetry and UV-visible and EPR spectroscopies. Thiomolybdates, in free or complex forms with copper ions, play an important role in the stability of 1(red) during its synthesis, since in its absence, 1(ox) is isolated. Both 1(red) and 1(ox) were structurally characterized by X-ray crystallography. EPR experiments showed that 1(red) is a Cu(II)-sulfur complex and revealed strong covalency on the copper-sulfur bonds. DFT calculations confirmed the spin density delocalization over the four sulfur atoms (76%) and copper (24%) atom, suggesting that 1(red) has a "thiyl radical character". Time dependent DFT calculations identified such ligand to ligand charge transfer transitions. Accordingly, 1(red) is better described by the two isoelectronic structures [Cu(I)(bdt2, 4S(3-,)*)](2-) ↔ [Cu(II)(bdt2, 4S(4-))](2-). On thermodynamic grounds, oxidation of 1(red) (doublet state) leads to 1(ox) singlet state, [Cu(III)(bdt2, 4S(4-))](1-).

  13. 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...

  14. Protons and electrons generated from a 5-{mu}m thick copper tape target irradiated by s-, circularly-, and p-polarized 55-fs laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z. [Advanced Photon Research Center, Japan Atomic Energy Agency, Umeimidai 8-1, Kizu, Kyoto 619-0215 (Japan); National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555 (Japan)], E-mail: lizhong@sinap.ac.cn; Daido, H. [Advanced Photon Research Center, Japan Atomic Energy Agency, Umeimidai 8-1, Kizu, Kyoto 619-0215 (Japan); Fukumi, A. [Advanced Photon Research Center, Japan Atomic Energy Agency, Umeimidai 8-1, Kizu, Kyoto 619-0215 (Japan); National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555 (Japan); Bulanov, S.V.; Sagisaka, A.; Ogura, K.; Yogo, A.; Nishiuchi, M.; Orimo, S.; Mori, M. [Advanced Photon Research Center, Japan Atomic Energy Agency, Umeimidai 8-1, Kizu, Kyoto 619-0215 (Japan); Oishi, Y.; Nayuki, T.; Fujii, T.; Nemoto, K. [Central Research Institute of Electric Power Industry, Nagasaka 2-6-1, Yokosuka, Kanagawa 240-0196 (Japan); Nakamura, S.; Noda, A. [Institute of Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Choi, I.W.; Sung, J.H.; Ko, D.-K.; Lee, J. [Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

    2007-10-01

    The angular distribution and energy spectra of energetic protons emitted from a 5-{mu}m thick copper tape target irradiated by p-, circularly-, and s-polarized 55-fs laser pulses with intensity of 8-9x10{sup 18} W/cm{sup 2} are measured. The protons are found in the rear target normal direction while the hot electrons are found in the laser propagation direction. The maximum energy of protons is equal to 1.34 MeV for p-polarized irradiation. The energy spectrum of protons depends strongly on the total amount of electrons but it does not so strongly depend on the electron angular distribution under our experiment conditions. Two-dimensional particle in cell simulations also show the maximal proton acceleration for the p-polarized pulse, less efficient acceleration for the circular polarization, and lower acceleration efficiency in the case of the s-polarization, which is related to the electron acceleration efficiency at the front side of the target.

  15. Micromachining with copper lasers

    Science.gov (United States)

    Knowles, Martyn R. H.; Bell, Andy; Foster-Turner, Gideon; Rutterford, Graham; Chudzicki, J.; Kearsley, Andrew J.

    1997-04-01

    In recent years the copper laser has undergone extensive development and has emerged as a leading and unique laser for micromachining. The copper laser is a high average power (10 - 250 W), high pulse repetition rate (2 - 32 kHz), visible laser (511 nm and 578 nm) that produces high peak power (typically 200 kW), short pulses (30 ns) and very good beam quality (diffraction limited). This unique set of laser parameters results in exceptional micro-machining in a wide variety of materials. Typical examples of the capabilities of the copper laser include the drilling of small holes (10 - 200 micrometer diameter) in materials as diverse as steel, ceramic, diamond and polyimide with micron precision and low taper (less than 1 degree) cutting and profiling of diamond. Application of the copper laser covers the electronic, aerospace, automotive, nuclear, medical and precision engineering industries.

  16. Inspection of copper canisters for spent nuclear fuel by means of Ultrasonic Array System. Electron beam evaluation, modeling and materials characterization

    International Nuclear Information System (INIS)

    Ping Wu; Lingvall, F.; Stepinski, T.

    1999-12-01

    Research conducted in the fifth phase of the SKB's study aimed at developing ultrasonic techniques for assessing EB welds copper canisters is reported here. This report covers three main tasks: evaluation of electron beam (EB) welds, modeling of ultrasonic fields and characterization of copper material. A systematic analysis of ultrasonic interaction and imaging of an EB weld has been performed. From the analysis of histograms of the weld ultrasonic image, it appeared that the porosity tended to be concentrated towards the upper side of a HV weld, and a guideline on how to select the gates for creating C-scans has been proposed. The spatial diversity method (SDM) has shown a limited ability to suppress grain noise both in the parent material (copper) and in the weld so that the ultrasonic image of the weld could be improved. The suppression was achieved at the price of reduced spatial resolution. The ability of wavelet filters to enhance flaw responses has been studied. An FIR (finite impulse response) filter, based on Sombrero mother wavelet, has yield encouraging results concerning clutter suppression. However, the physical explanation for the results is still missing and needs further research. For modeling of ultrasonic fields of the ALLIN array, an approach to computing the SIR (spatial impulse response) of a cylindrically curved, rectangular aperture has been developed. The aperture is split into very narrow strips in the cylindrically curved direction and SIR of the whole aperture by superposing the individual impulse responses of those strips. Using this approach, the SIR of the ALLIN array with a cylindrically curved surface has been calculated. The pulse excitation of normal velocity on the surface of the array, that is required for simulating actual ultrasonic fields, has been determined by measurement in combination with a deconvolution technique. Using the SIR and the pulse excitation obtained, the pulsed-echo fields from the array have been simulated

  17. Electronic structure of the perturbed blue copper site in nitrite reductase: Spectroscopic properties, bonding, and implications for the entatic/rack state

    Energy Technology Data Exchange (ETDEWEB)

    LaCroix, L.B.; Shadle, S.E.; Hedman, B.; Hodgson, K.O.; Solomon, E.I. [Stanford Univ., CA (United States); Wang, Y.; Averill, B.A. [Univ. of Virginia, Charlottesville, VA (United States)

    1996-08-21

    Low-temperature optical absorption, circular dichroism, magnetic circular dichroism, and sulfur K-edge X-ray absorption spectra have been measured for the green `blue` copper center (type 1) in Achromobacter cycloclastes nitrite reductase. Combined with density functional calculations, the results of these spectroscopies have been used to define the extremely `perturbed` electronic structure of this site relative to that of the prototypical `classic` site found in plastocyanin. Experimentally calibrated density functional calculations have been further used to determine the specific geometric distortions which generate the perturbed electronic structure. These studies indicate that the principal electronic structure changes in nitrite reductase, relative to plastocyanin, are a rotation of the Cu d{sub x(2)-y(2)} half-filled, highest occupied molecular orbital (HOMO) and an increase in the ligand field strength at the Cu center. These changes in Cu-ligand interactions result in the redistribution of absorption intensity in the charge transfer and ligand field transitions. Additionally, the new S(Met)-Cu interaction accounts for the unexpectedly high sulfur covalency in the HOMO. The increase in ligand field strength shifts all the d {yields} d transitions in nitrite reductase to nearly 1000 cm{sup -1} higher energy than their counterparts in plastocyanin, which accounts for the EPR spectral differences between the type 1 sites in these complexes. 97 refs., 7 figs., 3 tabs.

  18. Copper(0) Mediated Single Electron Transfer Controlled Radical Polymerization toward CF Bonds on Poly(vinylidene fluoride).

    Science.gov (United States)

    Tan, Shaobo; Zhang, Yanan; Niu, Zhijing; Zhang, Zhicheng

    2018-02-01

    The first copper(0) mediated controlled radical polymerization (CRP) of methyl methacrylate (MMA) toward CF bonds onto poly(vinylidene fluoride) (PVDF) is reported with rather high activity. By avoiding the halogen exchange, Cu 0 instead of Cu I complexes utilized as catalyst is responsible for the significantly improved polymerization activity. Using FH decoupled nuclear magnetic resonance technique, the grafting sites onto PVDF are finely located. From this, detailed topologic information including the grafting density, average length of each side chain, along with the overall grafted content of PMMA, is detected by tracking the polymerization as a function of time. This work offers not only a facile CRP strategy based on inactive CF bonds but also a deep insight into the cleavage of F-bearing compounds in organic chemistry. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Dislocation Loops with a Burgers Vector Produced by 1 MeV Electron Irradiation in FCC Copper-Nickel

    DEFF Research Database (Denmark)

    Leffers, Torben; Barlow, P.

    1975-01-01

    Dislocation loops with Burgers vector a are formed in Cu-Ni alloys during 1 MeV electron irradiation in a high-voltage electron microscope at 350°-400°C. The dislocation loops are of interstitial type and pure edge in character with line vectors. Some of the loops are seen to dissociate into loops...

  20. Multilevel cycle of anthropogenic copper.

    Science.gov (United States)

    Graedel, T E; van Beers, D; Bertram, M; Fuse, K; Gordon, R B; Gritsinin, A; Kapur, A; Klee, R J; Lifset, R J; Memon, L; Rechberger, H; Spatari, S; Vexler, D

    2004-02-15

    A comprehensive contemporary cycle for stocks and flows of copper is characterized and presented, incorporating information on extraction, processing, fabrication and manufacturing, use, discard, recycling, final disposal, and dissipation. The analysis is performed on an annual basis, ca. 1994, at three discrete governmental unit levels--56 countries or country groups that together comprise essentially all global anthropogenic copper stocks and flows, nine world regions, and the planet as a whole. Cycles for all of these are presented and discussed, and a "best estimate" global copper cycle is constructed to resolve aggregation discrepancies. Among the most interesting results are (1) transformation rates and recycling rates in apparently similar national economies differ by factors of two or more (country level); (2) the discard flows that have the greatest potential for copper recycling are those with low magnitude flows but high copper concentrations--electronics, electrical equipment, and vehicles (regional level); (3) worldwide, about 53% of the copper that was discarded in various forms was recovered and reused or recycled (global level); (4) the highest rate of transfer of discarded copper to repositories is into landfills, but the annual amount of copper deposited in mine tailings is nearly as high (global level); and (5) nearly 30% of copper mining occurred merely to replace copper that was discarded. The results provide a framework for similar studies of other anthropogenic resource cycles as well as a basis for supplementary studies in resource stocks, industrial resource utilization, waste management, industrial economics, and environmental impacts.

  1. Spurious effects of electron emission from the grids of a retarding field analyser on secondary electron emission measurements. Results on a (111) copper single crystal

    International Nuclear Information System (INIS)

    Pillon, J.; Roptin, D.; Cailler, M.

    1976-01-01

    Spurious effects of a four grid retarding field analyzer were studied for low energy secondary electron measurements. Their behavior was investigated and two peaks in the energy spectrum were interpreted as resulting from tertiary electrons from the grids. It was shown that the true secondary electron peak has to be separated from these spurious peaks. The spectrum and the yields sigma and eta obtained for a Cu(111) crystal after a surface cleanness control by Auger spectroscopy are given

  2. Jet-printed copper metallization

    Science.gov (United States)

    Hong, Cheong Min

    Macroelectronics is a technology for making electronic circuits over very large areas at low cost. Flat panel displays, sensor arrays, and thin film solar cells are examples of macroelectronics. Crucial to the success of this new technology is the development of inexpensive electronic processes, materials, and devices. Direct printing techniques, which eliminate processing steps and save device and process materials, are the key to high volume and high throughput manufacturing. Copper metallization has been receiving increasing attention in both microelectronics and macroelectronics. Copper has high conductivity, density, melting point, heat capacity, and thermal conductivity. However, copper is also hard to dry etch. For these reasons we have developed and demonstrated a directly printed copper source/drain metallization technique and applied it to the fabrication of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs). The maximum process temperature of 200°C is compatible with conventional active matrix liquid crystal display (AMLCD) technology. In this dissertation, we show the process of depositing copper films by jet printing. We discuss the preparation and the properties of the copper precursor material used in the jet printing. We survey the conversion process from copper precursor to copper under varying processing conditions. The resulting copper film is probed for its physical, electrical, and mechanical properties. To demonstrate the feasibility of the jet printing technique, we print copper source/drain contacts for a-Si:H TFTs. The photolithography-free TFT fabrication process uses the printed xerographic toner technique developed earlier in this laboratory. We show that functional TFTs can be made with printed copper source and drain contacts. The jet printing of copper contacts represents a further step toward an all-printed thin film transistor technology.

  3. Copper hypersensitivity

    DEFF Research Database (Denmark)

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

    2014-01-01

    . 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...... 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...

  4. Determination of the threshold-energy surface for copper using in-situ electrical-resistivity measurements in the high-voltage electron microscope

    International Nuclear Information System (INIS)

    King, W.E.; Merkle, K.L.; Meshii, M.

    1981-01-01

    A detailed study of the anisotropy of the threshold energy for Frenkel-pair production in copper was carried out experimentally, using in-situ electrical-resistivity measurements in the high-voltage electron microscope. These electrical-resistivity measurements, which are sensitive to small changes in point-defect concentration, were used to determine the damage or defect production rate. Damage-rate measurements in copper single crystals were carried out for approx.40 incident electron-beam directions and six electron energies from 0.4 to 1.1 MeV. The total cross section for Frenkel-pair production is proportional to the measured damage rate and can be theoretically calculated if the form of the threshold-energy surface is known. Trial threshold-energy surfaces were systematically altered until a ''best fit'' of the calculated to the measured total cross sections for Frenkel-pair production was obtained. The average threshold energy of this surface is 28.5 eV. The minimum threshold energy is 18 +- 2 eV and is located near . A ring of very high threshold energy (>50 eV) surrounds the direction. A damage function for single-defect production was derived from this surface and was applied to defect-production calculations at higher recoil energies. This function rises rather sharply from a value of zero at 17 eV to 0.8 at 42 eV. It has the value of 0.5 at 24.5 eV. Above 30 eV the slope of the curve begins to decrease, reflecting the presence of the high-energy regions of the threshold-energy surface. Both topographical and quantitative comparisons of the present surface with those in the literature were presented. Based on a chi 2 goodness-of-fit test, the present surface was found to predict the experimentally observed total cross sections for Frenkel-pair production significantly better than the other available surfaces. Also, the goodness of fit varied substantially less with energy and direction for the present surface

  5. Copper(I) thiocyanate (CuSCN) as a hole-transport material for large-area opto/electronics

    Science.gov (United States)

    Wijeyasinghe, Nilushi; Anthopoulos, Thomas D.

    2015-10-01

    Recent advances in large-area optoelectronics research have demonstrated the tremendous potential of copper(I) thiocyanate (CuSCN) as a universal hole-transport interlayer material for numerous applications, including transparent thin-film transistors, high-efficiency organic and hybrid organic-inorganic photovoltaic cells, and organic light-emitting diodes. CuSCN combines intrinsic hole-transport (p-type) characteristics with a large bandgap (>3.5 eV) which facilitates optical transparency across the visible to near infrared part of the electromagnetic spectrum. Furthermore, CuSCN is readily available from commercial sources while it is inexpensive and can be processed at low-temperatures using solution-based techniques. This unique combination of desirable characteristics makes CuSCN a promising material for application in emerging large-area optoelectronics. In this review article, we outline some important properties of CuSCN and examine its use in the fabrication of potentially low-cost optoelectronic devices. The merits of using CuSCN in numerous emerging applications as an alternative to conventional hole-transport materials are also discussed.

  6. Copper (II)

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    ABSTRACT: A Schiff base was prepared from the reaction of 2 - amino - 3 – methylbutanoic acid and 2, 4 - pentanedione. The reaction of the prepared Schiff base with ethanolic solution of copper (II) chloride formed diaquo bis( N – 2 – amino – 3 - methylbutyl - 2, 4 - pentanedionato) copper (II) complex. The Schiff base is ...

  7. Cold-induced imbibition damage of lettuce embryos: A study using cryo-scanning electron microscopy

    NARCIS (Netherlands)

    Nijsse, J.; Walther, P.; Hoekstra, F.

    2004-01-01

    The impact of rehydration on a multicellular organism was studied in lettuce (Lactuca sativa L.) embryos, using cryo-scanning electron microscopy (cryo-SEM). Naked embryos were sensitive to imbibitional stress, whereas embryos with an intact, thick-walled endosperm were not. Imbibitional injury to

  8. Identification of Copper(II) Complexes in Aqueous Solution by Electron Spin Resonance: An Undergraduate Coordination Chemistry Experiment.

    Science.gov (United States)

    Micera, G.; And Others

    1984-01-01

    Background, procedures, and results are provided for an experiment which examines, through electron spin resonance spectroscopy, complex species formed by cupric and 2,6-dihydroxybenzoate ions in aqueous solutions. The experiment is illustrative of several aspects of inorganic and coordination chemistry, including the identification of species…

  9. A facile, sensitive, and highly specific trinitrophenol assay based on target-induced synergetic effects of acid induction and electron transfer towards DNA-templated copper nanoclusters.

    Science.gov (United States)

    Li, Haiyin; Chang, Jiafu; Hou, Ting; Ge, Lei; Li, Feng

    2016-11-01

    Reliable, selective and sensitive approaches for trinitrophenol (TNP) detection are highly desirable with respect to national security and environmental protection. Herein, a simple and novel fluorescent strategy for highly sensitive and specific TNP assay has been successfully developed, which is based on the quenching of the fluorescent poly(thymine)-templated copper nanoclusters (DNA-CuNCs), through the synergetic effects of acid induction and electron transfer. Upon the addition of TNP, donor-acceptor complexes between the electron-deficient nitro-groups in TNP and the electron-donating DNA templates are formed, resulting in the close proximity between TNP and CuNCs. Moreover, the acidity of TNP contributes to the pH decrease of the system. These factors combine to dramatically quench the fluorescence of DNA-CuNCs, providing a "signal-off" strategy for TNP sensing. The as-proposed strategy demonstrates high sensitivity for TNP assay, and a detection limit of 0.03μM is obtained, which is lower than those reported by using organic fluorescent materials. More significantly, this approach shows outstanding selectivity over a number of TNP analogues, such as 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), 2,4-dinitrophenol (DNP), 3-nitrophenol (NP), nitrobenzene (NB), phenol (BP), and toluene (BT). Compared with previous studies, this method does not need complex DNA sequence design, fluorescent dye labeling, or sophisticated organic reactions, rendering the strategy with additional advantages of simplicity and cost-effectiveness. In addition, the as-proposed strategy has been adopted for the detection of TNP in natural water samples, indicating its great potential to be applied in the fields of public safety and environmental monitoring. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. High-resolution electron microscopy studies of the precipitation of copper under neutron irradiation in an Fe-1.3WT % Cu alloy.

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, A. C.

    1998-12-21

    We have studied by electron microscopy the copper-rich precipitates in an Fe-1.3wt%Cu model alloy irradiated with neutrons to doses of 8.61 x 10{sup {minus}3} dpa and 6.3 x 10{sup {minus}2} dpa at a temperature of {approximately}270 C. In the lower dose material a majority (ca. 60%)of the precipitates visible in high-resolution electron microscopy were timed 9R precipitates of size {approximately}2-4 nm, while ca. 40% were untwinned. In the higher dose material, a majority (ca. 75%) of visible precipitates were untwinned although many still seemed to have a 9R structure. The average angle {alpha} between the herring-bone fringes in the twin variants was measured as 125{degree}, not the 129{degree} characteristic of precipitates in thermally-aged and electron-irradiated material immediately after the bcc{r_arrow}9R martensitic transformation. We argue that these results imply that the bcc{r_arrow}9R transformation of small (<4 nm) precipitates under neutron irradiation takes place at the irradiation temperature of 270 C rather than after subsequent cooling. Preliminary measurements showed that precipitate sizes did not depend strongly on dose, with a mean diameter of 3.4 {+-} 0.7 nm for the lower dose material, and 3.0 {+-} 0.5 nm for the higher dose material. This result agrees with the previous assumption that the lack of coarsening in precipitates formed under neutron irradiation is a consequence of the partial dissolution of larger precipitates by high-energy cascades.

  11. Prospects of utilization of electron beam irradiation technology to augment control of SO2 and other emissions from Chilean copper smelting plants

    International Nuclear Information System (INIS)

    Villanueva, L.; Ahumada, L.; Ellison, W.; Chmielewski, A.G.; Zimek, Z.

    1998-01-01

    Analysis of potential utilization of applicable SO 2 -removal process for reduced-SO 2 -strength off-gases, including electron-beam irradiation, for incrementally improving overall abatement of SO 2 /SO 3 emissions from existing copper smelting facilities in Chile has been carried out. Off-gases are characterized by SO 2 content higher than 3,000 ppm, a complex chemical composition and highly oxidizing conditions, along with cyclical and fluctuating generation, reflecting relatively severe service. Laboratory tests with simulated high-SO 2 -strength process gas were performed at Polish Institute of Nuclear Chemistry and Technology. Test work proved the technical feasibility of removing SO 2 from ultra-high SO 2 content smelter gases by E-beam irradiation with ammonia injection. A laboratory unit with flow rate of 20 Nm 3 /h equipped with electron accelerator of 800 keV beam energy was used. Influence of different parameters on SO 2 removal efficiency, like temperature, dose, ammonia stoichiometry and water vapor content, has been established. Tests covered a high SO 2 content range, 2,000 to 10,000 ppm. A generic design has been deviced to address system arrangement, performance and control requirements. It encompasses upgrading of in-plant ventilation to the extent required by health standards, together with gas cleaning system based on EB Process. The arrangement of the facilities provides for gathering and treating off-gas from selected fugitive emission sources on a continuous basis, at the same time in-drafting a minimum amount of tramp air. An introductory dry dedusting stage uses activated coke injection in conjunction with a fabric filter to efficiently treat raw gas to remove heavy metals, including arsenic, along with particulate matter. Main conclusion of the two major stages of this work, i.e. experimental tests and engineering oriented studies, is that the EB Process is a simple and appropriate, cost-effective, chemical process that would, on a site

  12. 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.......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....... The growth mechanisms as well as the roles of different components in the catalyst were studied in situ using environmental transmission electron microscopy and infrared spectroscopy. On the basis of the understanding of carbon nanotube growth mechanisms, an MgO-supported FeCu catalyst was prepared...

  13. Electron injector for high-voltage model of collective accelerator

    International Nuclear Information System (INIS)

    Belikov, V.V.; Zvyagintsev, A.V.; Lymar', A.G.; Martynenko, P.A.; Khizhnyak, N.A.

    1987-01-01

    The design and test results of an electron gun with the beam compression and axial hole aimed at collective acceleration are presented. The electron gun is tested at 150 kV, the pulse duration being 12 ms. The hallow beam has 10 mm in diameter, with 1 mm thick wall, that corresponds to the compression degree of 200. The beam microperveance is 4.5 mA/V 3/2

  14. Composition profiles of several contaminated and cleaned surfaces of gold thick films on copper plates by Auger electron and secondary ion mass spectroscopies

    International Nuclear Information System (INIS)

    Komiya, S.; Mizuno, M.; Narusawa, T.; Maeda, H.; Yoshikawa, M.

    1974-01-01

    Preparation and evaluation of a clean Au film are investigated. Development of a preparation method for obtaining clean surface on a copper shell in the JFT-2a (DIVA) TOKAMAK toroidal vacuum chamber is the aim of the present work. Au films prepared by ion plating and vacuum evaporation have been analysed by a cylindrical mirror Auger electron analyser in combination with a quadrupole mass spectrometer during 2 keV Xe ion bombardment from a sputter ion gun over the whole range of thickness of several microns. Contaminants are found to segregate on the top surface and at the interface. To expose a clean Au surface by the ion bombardment, surface layers within 1000 A had to be removed from the surfaces contaminated by touching with either a naked hand or a nylon glove or covered by a small amount of Ti. Mutual diffusions across the interfaces are also analyzed as a function of the substrate temperature. A Nb sandwich layer inhibites effectively the mutual diffusion. (auth.)

  15. 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

  16. Copper delivery to chloroplast proteins and its regulation

    Directory of Open Access Journals (Sweden)

    Guadalupe eAguirre

    2016-01-01

    Full Text Available Copper is required for photosynthesis in chloroplasts of plants because it is a cofactor of plastocyanin, an essential electron carrier in the thylakoid lumen. Other chloroplast copper proteins are copper/zinc superoxide dismutase and polyphenol oxidase,¬ but these proteins seem to be dispensable under conditions of low copper supply when transcripts for these proteins undergo microRNA-mediated down regulation. Two ATP-driven copper transporters function in tandem to deliver copper to chloroplast compartments. This review seeks to summarize the mechanisms of copper delivery to chloroplast proteins and its regulation. We also delineate some of the unanswered questions that still remain in this field.

  17. Copper Vapor Laser with One-Beam Radiation of Diffraction Quality and Its Capabilities for Microprocessing of Materials for Electronic Engineering Products

    Directory of Open Access Journals (Sweden)

    N. A. Lyabin

    2014-01-01

    Full Text Available The structure, spatial, time and energy characteristics of copper vapor laser radiation (CVL with optical resonators possessing high spatial selectivity have been investigated: with an unstable resonator (UR with two convex mirrors and telescopic UR, and the conditions to form one-beam radiation with diffraction divergence and high stability of directivity pattern axis have been defined.The most weighty and prospective application of CVL with UR with two convex mirrors is to use it as a driving oscillator (DO in a copper vapor laser system (CVLS of the type: driving oscillator – power amplifier (DO – PA when diffraction beam radiating power and power density in a focused spot of 10-20 µm in diameter increases by 1-2 orders. Using industrial sealed-off active elements (AE of “Kulon” series with an average radiation power of 15-25 W as PAs the peak power density increases up to 1011 W/cm 2 while an application of AE “Crystal” with 30- 50 W power gives up to 1012 W/cm 2 , which is sufficient for efficient and qualitative microprocessing of materials up to 1…2 mm thick. Such a CVLS has become the basis for creating up-to-date automated laser technological installations (ALTI of “Karavella-1” and “Karavella-1M” types to manufacture precision parts of electronic engineering products (EEP of metal up to 0.5 mm thick and of non-metal up to 1.5…1.8 mm thick.CVL with a telescopic UR with an average power of 5-6 W diffraction radiation beam has become the basis for creating industrial ALTI “Karavella-2” and “Karavella-2M” to manufacture precision parts of electronic engineering products (EEP of metal up to 0.3 mm thick and of non-metal up to 0.5 – 0.7 mm thick.Practical work on all types of ALTI “Karavella” has shown a set of significant advantages of a laser way of pulsed microprocessing over the traditional ones, including electro-erosion machining: a wide range of structural metal and non-metal materials to be

  18. Effects of the copper vapour laser radiation in the root canal wall dentine: in vitro experiment using scanning electron microscopy and stereoscopy

    International Nuclear Information System (INIS)

    Silveira, Maria Claudia Garcia da

    2001-01-01

    Ten human uniradicular teeth had their crown removed along the cement-enamel junction and right away a proper chemical-surgical preparation of the radicular canals was done; the roots were longitudinally sectioned in order to allow the irradiation of the surfaces of the root canals wall dentine. The hemi-roots were separated in two groups: group I (control), with four hemi-roots, not irradiated; and group II, with 16 hemi-roots, subdivided in four sub-groups submitted to the following exposition time: 0,02 s; 0,05 s; 0,1 s and 0,5 s. A copper vapour laser was used with a 510,6 nm wavelength, total average power of 11 W in green and yellow emissions; average power of 6,5 W in green emission; pulse repetition rate of 16.000 Hz and pulse duration of 30 ns. The pulse energy (green line) is 0,4 mJ and the peak power 13,5 W. The laser cavity is unstable type (R 1 =3.900 mm and R 2 -250 mm). The focusing have focal length lens f 1 =250 mm and f 2 =150 mm. The beam quality is of the M 2 =5. The results obtained by scanning electron microscopy analysis showed the appearance of a cavity in the region of the laser beam incidence in the edges of this cavity, dentin was melt and resolidified presenting also cracks due to heat diffusion. Based on these results, we concluded that the size of the cavity formed in the dentin is directly proportional to the rate of exposure and, the more laser emission in the same area, more damage in the root canals wall dentin occurs. More studies need to be done with different exposition's time in order to obtain a safety protocol that does not cause injury in dental and support tissue. (author)

  19. Electronic transport measurements in the electron-doped high-temperature superconductor Praseodymium(2-x) Cerium(x) Copper (II) oxide(4+-delta)

    Science.gov (United States)

    Bach, Paul Leonard

    2011-12-01

    This thesis is composed of four major parts centered around the electron-doped superconductor Pr2-xCexCuO4+/-delta: angular magnetoresistance studies of antiferromagnetism, doping effects of oxygenation, Tc enhancement by the creation of superlattices, and comparison of high-temperature resistivity with the pnictides. The first part focuses on transport measurements of the magnetism in Pr2-xCexCuO4+/-delta and La 2-xCexCuO4+/-delta. It was found that the thermal evolution of the angular dependence of magnetoresistance in Pr 2-xCexCuO4+/-delta can be used to determine the Neel temperature in that material. This angular magnetoresistance technique was also applied to La2-xCexCuO4+/-delta ; evidence for antiferromagnetism in this system was observed as well. This section additionally develops angular magnetoresistance as a useful probe in other cuprate projects here described. The second part investigates over-oxygenated and irradiated Pr2-x CexCuO4+/-delta, in under- and optimal dopings. Resistivity, Hall effect, and angular magnetoresistance measurements show oxygen both doping and disordering the system, in agreement with over-doped films. The evolution of both the Hall effect and angular magnetoresistance shows that over-oxygenation results in significant changes in the number of charge carriers, regardless of the increase in scattering incurred. Additionally, this study indicates that annealing primarily removes apical oxygen, rather than other proposed behaviors. The third part studies multi-layer films of Pr2-xCex CuO4+/-delta and La2-xCexCuO 4+/-delta. These superlattices exhibit a significant Tc enhancement over component layers' T cs. Interface effects are excluded as a source of this Tc increase based upon critical current measurments. The Tc enhancement is found to be due to charge redistribution. Based on Hall and angular magnetoresistance measurements, the result of this redistribution is slightly net-under-doped films. The fourth part uses Pr2-xCexCuO4

  20. Brazing copper to dispersion-strengthened copper

    Energy Technology Data Exchange (ETDEWEB)

    Ryding, D.G.; Allen, D.; Lee, R.

    1996-08-01

    The Advanced Photon Source (APS) is a state-of-the-art synchrotron light source that will produce intense x-ray beams, which will allow the study of smaller samples and faster reactions and processes at a greater level of detail that has been possible to date. The beam is produced by using third-generation insertion devices in a 7 GeV electron/positron storage ring that is 1100 meters in circumference. The heat load from these intense high power devices is very high and certain components must sustain total heat loads of 3 to 15 kW and heat fluxes of 30 W/mm{sup 2}. Because the beams will cycle on and off many times, thermal shock and fatigue will be a problem. High heat flux impinging on a small area causes a large thermal gradient that results in high stress. GlidCop{reg_sign}, a dispersion strengthened copper, is the desired material because of its high thermal conductivity and superior mechanical properties as compared to copper and its alloys. GlidCop is not amenable to joining by fusion welding, and brazing requires diligence because of high diffusivity. Brazing procedures were developed using optical and scanning electron microscopy.

  1. The C-O stretch as an unprecedently large spectral marker for the electron transfer between copper(II) and a phenolate anion

    Czech Academy of Sciences Publication Activity Database

    Milko, Petr; Roithová, Jana; Tsierkezos, Nikos; Schröder, Detlef

    2008-01-01

    Roč. 130, č. 23 (2008), s. 7186-7187 ISSN 0002-7863 R&D Projects: GA AV ČR KJB400550704 Institutional research plan: CEZ:AV0Z40550506 Keywords : copper * density functional calculations * IR spectroscopy * mass spectroscopy * phenols Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 8.091, year: 2008

  2. Copper atomic-scale transistors

    Directory of Open Access Journals (Sweden)

    Fangqing Xie

    2017-03-01

    Full Text Available We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO4 + H2SO4 in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate. The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and −170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes (Ubias influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1G0 (G0 = 2e2/h; with e being the electron charge, and h being Planck’s constant or 2G0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors.

  3. LEP Radio Frequency Copper Cavity

    CERN Multimedia

    The pulse of a particle accelerator. 128 of these radio frequency cavities were positioned around CERN's 27-kilometre LEP ring to accelerate electrons and positrons. The acceleration was produced by microwave electric oscillations at 352 MHz. The electrons and positrons were grouped into bunches, like beads on a string, and the copper sphere at the top stored the microwave energy between the passage of individual bunches. This made for valuable energy savings as it reduced the heat generated in the cavity.

  4. Tunable synthesis of copper nanotubes

    International Nuclear Information System (INIS)

    Kaniukov, E; Yakimchuk, D; Kozlovsky, A; Shlimas, D; Zdorovets, M; Kadyrzhanov, K

    2016-01-01

    Simple method of tunable synthesis of copper nanotubes based on template synthesis was developed. A comprehensive study of the structural, morphological and electrical characteristics of the obtained nanostructures was carried out. Characterization of structural features was made by methods of scanning electron microscopy, energy dispersive spectroscopy and X-ray diffractometry analysis. Evaluation of wall thickness is made by methods of gas permeability. Electrical conductivity of nanotubes was define in the study of their current-voltage characteristics. The possibility to control of copper nanotubes physical properties by variation of the deposition parameters was shown. (paper)

  5. Chemistry of the copper silicon interface

    International Nuclear Information System (INIS)

    Ford, M.J.; Sashin, V.A.; Nixon, K.

    2002-01-01

    Full text: Copper and silicon readily interdiffuse, even at room temperature, to form an interface which can be several nanometers thick. Over the years considerable effort has gone into investigating the diffusion process and chemical nature of the interface formed. Photoemission measurements give evidence for the formation of a stable suicide with a definite stoichiometry, Cu 3 Si. This is evidenced by splitting of the Si LVV Auger line and slight shifts and change in shape of the copper valence band density of states as measured by ultra-violet photoemission. In this paper we present calculations of the electronic structure of copper suicide, bulk copper and silicon, and preliminary measurements of the interface by electron momentum spectroscopy. Densities of states for copper and copper suicide are dominated by the copper 3d bands, and difference between the two compounds are relatively small. By contrast, the full band structures are quite distinct. Hence, experimental measurements of the full band structure of the copper on silicon interface, for example by EMS, have the potential to reveal the chemistry of the interface in a detailed way

  6. Exploring template-bound dinuclear copper porphyrin nanorings by EPR spectroscopy† †Electronic supplementary information (ESI) available: Description of the experimental conditions and parameters applied; supplementary data sets and simulations; visualization of the calculated hyperfine and nuclear quadrupole tensors. See DOI: 10.1039/c6sc01810f Click here for additional data file.

    Science.gov (United States)

    Richert, Sabine; Cremers, Jonathan; Anderson, Harry L.

    2016-01-01

    Electron paramagnetic resonance (EPR) spectroscopy has been used to study the molecular geometry as well as metal–ligand interactions in ten-membered porphyrin nanorings (c-P10Cu2) containing two copper and eight zinc centers. The presence of copper in the structures allows intramolecular interactions, including dipolar interactions between electron spins and hyperfine interactions to be quantified. Results obtained for c-P10Cu2 samples bound to two molecular templates with four or five binding sites, respectively, are compared to those obtained for a sample of the porphyrin ring in the absence of any templates. It is shown that the observed lower binding affinity of the nitrogen ligand to copper as compared to zinc has a strong impact on the geometries of the respective template-bound c-P10Cu2 structures. The interaction between the central copper atom and nitrogen ligands is weak, but pulsed EPR hyperfine techniques such as ENDOR and HYSCORE are very sensitive to this interaction. Upon binding of a nitrogen ligand to copper, the hyperfine couplings of the in-plane nitrogen atoms of the porphyrin core are reduced by about 3 MHz. In addition, the copper hyperfine couplings as well as the g-factors are altered, as detected by continuous wave EPR. DFT calculations of the hyperfine coupling tensors support the assignment of the measured couplings to the nuclei within the structure and reproduce the experimentally observed trends. Finally, Double Electron Electron Resonance (DEER) is used to measure the distances between the copper centers in a range between 2.5 and 5 nm, revealing the preferred geometries of the template-bound nanorings. PMID:28451129

  7. A new copper(II) chelate complex with tridentate ligand: Synthesis, crystal and molecular electronic structure of aqua-(diethylenetriamine-N, N‧, N‧‧)-copper(II) sulfate monohydrate and its fire retardant properties

    Science.gov (United States)

    Lavrenyuk, H.; Mykhalichko, O.; Zarychta, B.; Olijnyk, V.; Mykhalichko, B.

    2015-09-01

    The crystals of a new aqua-(diethylenetriamine-N, N‧, N‧‧)-copper(II) sulfate monohydrate have been synthesized by direct interaction of solid copper(II) sulfate pentahydrate with diethylenetriamine (deta). The crystal structure of [Cu(deta)H2O]SO4ṡH2O (1) has been determined by X-ray diffraction methods at 100 K and characterized using X-ray powder diffraction pattern: space group P 1 bar, a = 7.2819(4), b = 8.4669(4), c = 8.7020(3) Å, α = 83.590(3), β = 89.620(4), γ = 84.946(4)°, Z = 2. The environment of the Cu(II) atom is a distorted, elongated square pyramid which consists of three nitrogen atoms of the deta molecule and oxygen atom of the water molecule in the basal plane of the square pyramid (the average lengths of the in-plane Cu-N and Cu-O bonds are 2.00 Å). The apical position of the coordination polyhedron is occupied by complementary oxygen atom of the sulfate anion (the length of the axial Cu-O bond is 2.421(1) Å). The crystal packing is governed by strong hydrogen bonds of O-H⋯O and N-H⋯O types. The ab initio quantum-chemical calculations have been performed by the restricted Hartree-Fock method with a basis set 6-31∗G using the structural data of [Cu(deta)H2O]SO4ṡH2O. It has been ascertained that the degenerate d-orbitals of the Cu2+ ion split under the co-action of both the square-pyramidal coordination and the chelation. It is significant that visually observed crystals color (blue-violet) of the [Cu(deta)H2O]SO4ṡH2O complex is in good agreement with the calculated value of wavelength of visible light (λ = 5735 Å) which is closely related to the energy of the absorbed photon (Δ = 2.161 eV). Furthermore, the stereo-chemical aspect of influence of the CuSO4 upon combustibility of modified epoxy-amine polymers has been scrutinized.

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    Ni Lixiao; Li Shiyin

    2008-01-01

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

  11. Industrial Tests to Modify Molten Copper Slag for Improvement of Copper Recovery

    Science.gov (United States)

    Guo, Zhengqi; Zhu, Deqing; Pan, Jian; Zhang, Feng; Yang, Congcong

    2018-04-01

    In this article, to improve the recovery of copper from copper slag by flotation process, industrial tests of the modification process involving addition of a composite additive into molten copper slag were conducted, and the modified slag was subjected to the flotation process to confirm the modification effect. The phase evolution of the slag in the modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that more copper was transformed and enriched in copper sulfide phases. The magnetite content in the modified slag decreased, and that of "FeO" increased correspondingly, leading to a better fluidity of the molten slag, which improved the aggregation and growth of fine particles of the copper sulfide minerals. Closed-circuit flotation tests of the original and modified slags were conducted, and the results show that the copper recovery increased obviously from 69.15% to 73.38%, and the copper grade of concentrates was elevated slightly from 20.24% to 21.69%, further confirming that the industrial tests of the modification process were successful. Hence, the modification process has a bright future in industrial applications for enhancing the recovery of copper from the copper slag.

  12. Protection by high velocity thermal spraying coatings on thick walled permanent and interim store components for the diminution of repairs, corrosion and costs 'SHARK'. Overview at the end of the project; Schutz durch Hochgeschwindigkeitsflammspritzschichten auf dickwandigen End- und Zwischenlagerbauteilen zur Reduktion von Reparaturen, Korrosion und Kosten 'SHARK'. Ein Ueberblick zum Abschluss des Projektes

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Sabine; Hassel, Thomas; Bach, Friedrich-Wilhelm [Unterwassertechnikum Hannover, Garbsen (Germany). Inst. fuer Werkstoffkunde; Steinwarz, Wolfgang; Dyllong, Nobert; Tragsdorf, Inga Maren [Siempelkamp Nukleartechnik GmbH, Krefeld (Germany)

    2012-04-15

    The corrosion protection of the internal space of thick-walled interim and permanent storage facility components, such as Castor {sup copyright} containers, are ensured nowadays by a galvanic nickel layer. The method has proved itself and protects the base material of the containers at the underwater loading in the Nuclear power station from a corrosive attack. Although, the galvanic nickel plating is a relatively time consuming method, it lasts for several days for each container, and is with a layer thickness of 1,000 {mu}m also expensive. To develop an alternative, faster and more economical method, a BMBF research project named - 'SHARK - protection by high velocity thermal spraying layers on thick-walled permanent and interim store components for the diminution of repairs, corrosion and costs' in cooperation between Siempelkamp Nukleartechnik GmbH and the Institute of Materials Science of the Leibniz University of Hanover was established to investigate the suitability of the high velocity oxy fuel spraying technology (HVOF) for the corrosion protective coating of thickwalled interim and permanent storage facility components. Since the permanent storage depot components are manufactured from cast iron with globular graphite, this material was exclusively used as a base material in this project. The evaluation of the economical features of the application of different nickel base spraying materials on cast iron substratum was in focus, as well as the scientific characterization of the coating systems with regard to the corrosion protective properties. Furthermore, the feasibility of the transfer of the laboratory results on a large industrial setup as well as a general suitability of the coating process for a required repair procedure was to be investigated. The preliminary examination program identified chromium containing spraying materials as successful. Results of the preliminary examination program have been used for investigations with the CASOIK

  13. Separation of copper-64 from copper phthalocyanine

    International Nuclear Information System (INIS)

    Battaglin, R.I.M.

    1979-01-01

    The separation of copper-64 from irradiated copper phthalocyanine by Szilard-Chalmers effect is studied. Two methods of separation are used: one of them is based on the dissolution of the irradiated dry compound in concentrated sulfuric acid following its precipitation in water. In the other one the compound is irradiated with water in paste form following treatment with water and hydrochloric acid. The influence of the crystal form of the copper phthalocyanine on the separation yield of copper-64 is shown. Preliminary tests using the ionic exchange technique for purification and changing of copper-64 sulfate to chloride form are carried out. The specific activity using the spectrophotometric technique, after the determination of the copper concentration in solution of copper-64, is calculated. (Author) [pt

  14. Modification of polycrystalline copper by proton irradiation

    International Nuclear Information System (INIS)

    Garcia S, F.; Cabral P, A.; Saniger B, J.M.; Banuelos, J.G.; Barragan V, A.

    1997-01-01

    Polished copper samples were irradiated with proton beams of 300 and 700 keV at room temperature and at -150 Centigrade. In this work the obtained results are reported when such copper irradiated samples are analysed with Sem, Tem, AFM. The Sem micrographs showed evident changes in surface of these copper samples, therefore an EDAX microanalysis was done for its characterization. additionally, the Tem micrographs showed heaps formation until 200 nm. Its electron diffraction spectra indicated that these heaps consist of a copper compound. Finally with AFM were observed changes in coloration of the irradiated sample surface, as well as changes in texture and rugosity of them. These results show in general that irradiation process with protons which is known as an innocuo process produces changes in the copper properties. (Author)

  15. Comparison of MCNP trademark and MAVRIC for the case of a radiography experiment with thick-walled multi-layered shielding and Co-60 source; Vergleich von MCNP trademark und MAVRIC am Beispiel eines Durchstrahlungsexperiments mit dickwandiger mehrschichtiger Abschirmung und Co-60 Quelle

    Energy Technology Data Exchange (ETDEWEB)

    Schloemer, L.; Phlippen, P.W. [WTI Wissenschaftlich-Technische Ingenieurberatung GmbH, Juelich (Germany)

    2012-11-01

    The application of calculation methods to demonstrate an effective radiation shielding requires validation with appropriate measurements. Experimental data on the shielding of high-energy gamma radiation representing the situation of a thick-wall container with lead insert and significant self-shielding of the inventory is not publicly available. Therefore the shielding efficiency of multi-layered shielding (Pb, polyethylene) of a container was measured using an industrial Co-60 point source and a precisely calibrated measuring system for different shielding situations and measuring positions outside of the shielding. The calculations were performed using the codes MCNP trademark and MAVRIC. The deviations of calculated and experimental data are constant within the uncertainty of the experimental set-up, no distance dependent drift was identified.

  16. Mononuclear copper(I) bromide complexes chelated with bis(pyrazol-1-ylmethyl)-pyridine ligands: Structures, electronic properties and solid state photoluminescence

    International Nuclear Information System (INIS)

    Wu, Fengshou; Tong, Hongbo; Wang, Kai; Zhang, Xiulan; Zhang, Jie; Zhu, Xunjin; Wong, Wai-Kwok

    2016-01-01

    A series of mononuclear Cu(I) complexes formulated as [Cu(L)Br] were prepared by reaction of copper(I) bromide with equimolar amounts of bis(pyrazol-1-ylmethyl)- pyridine (L) in toluene solvent. The five complexes were characterized by UV/Vis, 1 H NMR and MS spectroscopy. The molecular structure of complex B2 has been established by single-crystal analyses. It features a tetrahedral copper center surrounded by three nitrogen atoms from the chelating pyridine–pyrazole ligand and one halogen atom. The complexes are luminescent in the solid state at ambient temperature. Intense green or yellow emission is observed, with maxima in the range of 520–569 nm, depending on the substitution pattern of the pyridine–pyrazole ligands used for the complexation. The emission lifetimes of the complexes in powder were in a dozen microseconds, indicating that the emission may be phosphorescent in origin. Moreover, the emission energies of the complexes show a concentration-dependence in the rigid environment, probably due to the different geometry in the lowest excited states. The emission of the complexes was assigned to metal-to-ligand charge-transfer excited states with some mixing of the halide-to-ligand characters, which was further supported by means of density functional theory (DFT) calculations.

  17. Preparation of single-crystal copper ferrite nanorods and nanodisks

    International Nuclear Information System (INIS)

    Du Jimin; Liu Zhimin; Wu Weize; Li Zhonghao; Han Buxing; Huang Ying

    2005-01-01

    This article, for the first time, reports the preparation of single-crystal copper ferrite nanorods and nanodisks. Using amorphous copper ferrite nanoparticles synthesized by reverse micelle as reaction precursor, single-crystal copper ferrite nanorods were synthesized via hydrothermal method in the presence of surfactant polyethylene glycol (PEG), however, copper ferrite nanodisks were prepared through the same procedures except the surfactant PEG. The resulting nanomaterials have been characterized by powder X-ray diffraction (XRD), selected electron area diffraction (SEAD), and transmission electron microscopy (TEM). The bulk composition of the samples was determined by means of X-ray photoelectron spectroscopy (XPS)

  18. Aquatic Life Criteria - Copper

    Science.gov (United States)

    Documents pertain to Aquatic Life Ambient Water Quality criteria for Copper (2007 Freshwater, 2016 Estuarine/marine). These documents contain the safe levels of Copper in water that should protect to the majority of species.

  19. 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....

  20. Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation

    Science.gov (United States)

    Liu, Ling-ling; Jia, Bo; Zhao, Fang; Huang, Wei-dong; Zhan, Ji-cheng

    2015-01-01

    At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo) and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China’s stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress. PMID:26030864

  1. Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation.

    Science.gov (United States)

    Sun, Xiang-Yu; Zhao, Yu; Liu, Ling-Ling; Jia, Bo; Zhao, Fang; Huang, Wei-Dong; Zhan, Ji-Cheng

    2015-01-01

    At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo) and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China's stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress.

  2. Copper clean-up procedure for ultrasonic extraction and analysis of pyrethroid and phenylpyrazole pesticides in sediments by gas chromatography-electron capture detection

    Energy Technology Data Exchange (ETDEWEB)

    Wu Jun; Lin Youjian; Lu Jian; Wilson, Chris, E-mail: pcwilson@ufl.edu

    2011-08-15

    A rapid ultrasonic extraction method coupled with a heated-copper clean-up procedure for removing interfering constituents was developed for analyzing pyrethroid and phenylpyrazole pesticides in sediments. Incubation of the 60 mL extract with 12 g copper granules at 60 {sup o}C for 2 h was determined to be the optimal conditions for removing the interfering constituents. Eleven pyrethroid and phenylpyrazole pesticides were spiked into sediment samples to determine the effectiveness of the ultrasonic extraction method. The average recoveries of pyrethroids and phenylpyrazoles in sediment at 4 {sup o}C storage on day 0, 1, 7, 14, and 21 ranged from 98.6 to 120.0%, 79.2 to 116.0%, 85.0 to 119.7%, 93.6 to 118.7%, and 92.1 to 118.2%, respectively, with all percent relative standard deviations less than 10% (most < 6%). This illustrated the stability of pyrethroids and phenylpyrazoles in sediment during sediment aging at 4 {sup o}C. Recoveries of the pesticides ranged from 98.6% to 120.0% for lowest fortification level (2-16 {mu}g kg{sup -1}), from 97.8% to 117.9% for middle fortification level (10-80 {mu}g kg{sup -1}), and from 94.3% to 118.1% for highest fortification level (20-160 {mu}g kg{sup -1}). Relative standard deviations of pesticide recoveries were usually less than 7%. Method detection limits of target pesticides ranged from 0.22 {mu}g kg{sup -1} to 3.72 {mu}g kg{sup -1}. Furthermore, field sediment samples collected from four residential lakes during a three-month monitoring period were analyzed to evaluate the effectiveness of this method. Bifenthrin was detected in all of sediment samples (highest concentration 260.33 {+-} 41.71 {mu}g kg{sup -1}, lowest concentration 5.68 {+-} 0.38 {mu}g kg{sup -1}), and fipronil sulfone was detected at least once in sediment samples collected from three sites with concentrations ranging from 1.73 {+-} 0.53 to 7.53 {+-} 0.01 {mu}g kg{sup -1}. - Highlights: {yields} A rapid extraction and copper-based clean-up method was

  3. Demands made on high-purity copper for special purposes

    International Nuclear Information System (INIS)

    Roettges, D.

    1977-01-01

    The properties (electrical resistivity, residual impurities) of high-purity copper produced on a technical scale are reported as well as its practical applications. The paper discusses a high-oxygen copper (SV) with low residual resistivity at low temperatures and an oxygen-free (hydrogen-stable) copper (BE electronic) with low gas content. The SV quality has been specially developed for use as stabilizer in superconductors while the BE quality is used in high and ultrahigh vacuum. (GSC) [de

  4. Demystifying Controlling Copper Corrosion

    Science.gov (United States)

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

  5. Copper clean-up procedure for ultrasonic extraction and analysis of pyrethroid and phenylpyrazole pesticides in sediments by gas chromatography-electron capture detection.

    Science.gov (United States)

    Wu, Jun; Lin, Youjian; Lu, Jian; Wilson, Chris

    2011-08-15

    A rapid ultrasonic extraction method coupled with a heated-copper clean-up procedure for removing interfering constituents was developed for analyzing pyrethroid and phenylpyrazole pesticides in sediments. Incubation of the 60 mL extract with 12 g copper granules at 60 °C for 2h was determined to be the optimal conditions for removing the interfering constituents. Eleven pyrethroid and phenylpyrazole pesticides were spiked into sediment samples to determine the effectiveness of the ultrasonic extraction method. The average recoveries of pyrethroids and phenylpyrazoles in sediment at 4 °C storage on day 0, 1, 7, 14, and 21 ranged from 98.6 to 120.0%, 79.2 to 116.0%, 85.0 to 119.7%, 93.6 to 118.7%, and 92.1 to 118.2%, respectively, with all percent relative standard deviations less than 10% (most <6%). This illustrated the stability of pyrethroids and phenylpyrazoles in sediment during sediment aging at 4 °C. Recoveries of the pesticides ranged from 98.6% to 120.0% for lowest fortification level (2-16 μg kg⁻¹), from 97.8% to 117.9% for middle fortification level (10-80 μg kg⁻¹), and from 94.3% to 118.1% for highest fortification level (20-160 μg kg⁻¹). Relative standard deviations of pesticide recoveries were usually less than 7%. Method detection limits of target pesticides ranged from 0.22 μg kg⁻¹ to 3.72 μg kg⁻¹. Furthermore, field sediment samples collected from four residential lakes during a three-month monitoring period were analyzed to evaluate the effectiveness of this method. Bifenthrin was detected in all of sediment samples (highest concentration 260.33±41.71 μg kg⁻¹, lowest concentration 5.68±0.38 μg kg⁻¹, and fipronil sulfone was detected at least once in sediment samples collected from three sites with concentrations ranging from 1.73±0.53 to 7.53±0.01 μg kg⁻¹. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Design of an electronically operated flow-through respirometer and its use to investigate the effects of copper on the respiration rate of the amphipod gammarus pulex (L.)

    Energy Technology Data Exchange (ETDEWEB)

    Kedwards, J.T.; Blockwell, S.J.; Tylor, E.J.; Pascoe, T.D. [Univ. of Wales College of Cardiff (United Kingdom)

    1996-12-31

    The use of oxygen consumption as a measure of metabolism has resulted in the development of many types of respirometer. These can be classified into three types. Firstly, there is the closed system in which oxygen concentration is measured at the beginning and end of the experiment and an organism`s respiratory rate calculated from the decrease in oxygen concentration and the volume of the vessel. Secondly, there is a system in which respired oxygen is replaced by oxygen from the surrounding air and the resultant change in air volume is measured gasometrically. A third approach, and the one employed in this study, utilises an open flow-through system in which water passes through a chamber containing an animal and the oxygen concentration is measured and compared to that of a reference chamber without an animal. The difference in oxygen concentration is then used to determine the respiration rate of the test animal. In open flow-through systems excretory products are washed away and water is not left stagnant as may occur in closed techniques. In addition, the open flow technique provides a constant oxygen concentration, avoids stress to animals with oxygen concentration-dependent metabolism and allows the simulation of low oxygen tension environments. Despite these obvious advantages the use of flow-through respirometers has been somewhat limited due to difficulties in calibration and complexity in construction and operation (Edwards and Learner 1960). The purpose of this investigation was to design a flow-through respirometer which is sufficiently sensitive to detect pollutant-induced respiratory changes in freshwater invertebrates and which permits automated continuous recording of the respiration of several animals maintained individually. In order to evaluate the system the effect of copper (prepared form cupric sulphate, CuSO{sub 4}.5H{sub 2}O) on the respiration of the shrimp Gammarus pulex was studied. 26 refs., 2 figs., 1 tab.

  7. Surface films and corrosion of copper

    International Nuclear Information System (INIS)

    Hilden, J.; Laitinen, T.; Maekelae, K.; Saario, T.; Bojinov, M.

    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

  8. Probing the localization of charge and the extent of disorder through electronic transport on Au nanoparticle–copper phthalocyanine multijunction networks

    Czech Academy of Sciences Publication Activity Database

    Balliou, A.; Kazim, Samrana; Pfleger, Jiří; Rakušan, J.; Skoulatakis, G.; Kennou, S.; Glezos, N.

    2016-01-01

    Roč. 253, č. 5 (2016), s. 1009-1019 ISSN 0370-1972 R&D Projects: GA MŠk(CZ) 7AMB12GR022; GA ČR(CZ) GAP108/12/1143 Institutional support: RVO:61389013 Keywords : Au nanoparticles * carrier localization * electrical transport Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.674, year: 2016

  9. Temperature Independent Catalytic Two-Electron Reduction of Dioxygen by Ferrocenes with a Tris[2-(2-pyridyl)ethyl]amine-Copper(II) Catalyst in the Presence of Perchloric Acid

    Science.gov (United States)

    Das, Dipanwita; Lee, Yong-Min; Ohkubo, Kei; Nam, Wonwoo; Karlin, Kenneth D.; Fukuzumi, Shunichi

    2013-01-01

    Selective two-electron plus two-proton (2e−/2H+) reduction of O2 to hydrogen peroxide by ferrocene (Fc) or 1,1′-dimethylferrocene (Me2Fc) in the presence of perchloric acid is catalyzed efficiently by a mononuclear copper(II) complex, [CuII(tepa)]2+ {tepa = tris[2-(2-pyridyl)ethyl]amine} (1) in acetone. The E1/2 value for [CuII(tepa)]2+ as measured by cyclic voltammetry is 0.07 V vs Fc/Fc+ in acetone, being significantly positive, which makes it possible to use relatively weak one-electron reductants such as Fc and Me2Fc for the overall two-electron reduction of O2. Fast electron transfer from Fc or Me2Fc to 1 affords the corresponding CuI complex, [CuI(tepa)]+ (2), which reacts at low temperature (193 K) with O2, however only in presence of HClO4 to afford the hydroperoxo complex, [CuII(tepa)(OOH)]2+ (3). The detailed kinetic study on the homogeneous catalytic system reveals the rate-determining step to be the O2-binding process in the presence of HClO4 at lower temperature as well as at room temperature. The O2-binding kinetics in the presence of HClO4 were studied, demonstrating that the rate of formation of the hydroperoxo complex (3) as well as the overall catalytic reaction remained virtually the same with changing temperature. The apparent lack of an activation energy for the catalytic two-electron reduction of O2 is shown to result from the existence of a pre-equilibrium between 2 and O2 prior to the formation of the hydroperoxo complex 3. No further reduction of [CuII(tepa)(OOH)]2+ (3) by Fc or Me2Fc occurred, and instead 3 is protonated by HClO4 to yield H2O2 accompanied by regeneration of 1, thus completing the catalytic cycle for the two-electron reduction of O2 by Fc or Me2Fc. PMID:23394287

  10. Microstructural characterization of copper corrosion in aqueous and soil environments

    International Nuclear Information System (INIS)

    Srivastava, A.; Balasubramaniam, R.

    2005-01-01

    Scanning electron microscopy has been used to investigate the surface films on pure copper after exposure to different aqueous and soil environments, containing chloride, sulfide and ammonium salts. The morphology of the films formed on copper surface in aqueous and soil environments was different for the same amount of pollutants. The surface films formed in soil environments were not homogenous in contrast to the films formed in aqueous environments. The damaging effect of chloride ions and the benign role of sulfide ions were revealed in both the environments. Local compositional analysis confirmed that the surface films formed on copper consisted predominantly of copper and oxygen

  11. Microplastic Deformation of Submicrocrystalline Copper at Room and Elevated Temperatures

    Science.gov (United States)

    Dudarev, E. F.; Pochivalova, G. P.; Tabachenko, A. N.; Maletkina, T. Yu.; Skosyrskii, A. B.; Osipov, D. A.

    2017-02-01

    of investigations of submicrocrystalline copper subjected to cold rolling after abc pressing by methods of backscatter electron diffraction and x-ray diffraction analysis are presented. It is demonstrated that after such combined intensive plastic deformation, the submicrocrystalline structure with average grain-subgrain structure elements having sizes of 0.63 μm is formed with relative fraction of high-angle grain boundaries of 70% with texture typical for rolled copper. Results of investigation of microplastic deformation of copper with such structure at temperatures in the interval 295-473 K and with submicrocrystalline structure formed by cold rolling of coarse-grained copper are presented.

  12. Study of the Cys-His bridge electron transfer pathway in a copper-containing nitrite reductase by site-directed mutagenesis, spectroscopic, and computational methods.

    Science.gov (United States)

    Cristaldi, Julio C; Gómez, María C; González, Pablo J; Ferroni, Felix M; Dalosto, Sergio D; Rizzi, Alberto C; Rivas, María G; Brondino, Carlos D

    2018-03-01

    The Cys-His bridge as electron transfer conduit in the enzymatic catalysis of nitrite to nitric oxide by nitrite reductase from Sinorhizobium meliloti 2011 (SmNir) was evaluated by site-directed mutagenesis, steady state kinetic studies, UV-vis and EPR spectroscopic measurements as well as computational calculations. The kinetic, structural and spectroscopic properties of the His171Asp (H171D) and Cys172Asp (C172D) SmNir variants were compared with the wild type enzyme. Molecular properties of H171D and C172D indicate that these point mutations have not visible effects on the quaternary structure of SmNir. Both variants are catalytically incompetent using the physiological electron donor pseudoazurin, though C172D presents catalytic activity with the artificial electron donor methyl viologen (k cat =3.9(4) s -1 ) lower than that of wt SmNir (k cat =240(50) s -1 ). QM/MM calculations indicate that the lack of activity of H171D may be ascribed to the N δ1 H…OC hydrogen bond that partially shortcuts the T1-T2 bridging Cys-His covalent pathway. The role of the N δ1 H…OC hydrogen bond in the pH-dependent catalytic activity of wt SmNir is also analyzed by monitoring the T1 and T2 oxidation states at the end of the catalytic reaction of wt SmNir at pH6 and 10 by UV-vis and EPR spectroscopies. These data provide insight into how changes in Cys-His bridge interrupts the electron transfer between T1 and T2 and how the pH-dependent catalytic activity of the enzyme are related to pH-dependent structural modifications of the T1-T2 bridging chemical pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Temperature and Copper Concentration Effects on the Formation of Graphene-Encapsulated Copper Nanoparticles from Kraft Lignin

    Directory of Open Access Journals (Sweden)

    Weiqi Leng

    2017-06-01

    Full Text Available The effects of temperature and copper catalyst concentration on the formation of graphene-encapsulated copper nanoparticles (GECNs were investigated by means of X-ray diffraction, Fourier transform infrared spectroscopy-attenuated total reflectance, and transmission electron microscopy. Results showed that higher amounts of copper atoms facilitated the growth of more graphene islands and formed smaller size GECNs. A copper catalyst facilitated the decomposition of lignin at the lowest temperature studied (600 °C. Increasing the temperature up to 1000 °C retarded the degradation process, while assisting the reconfiguration of the defective sites of the graphene layers, thus producing higher-quality GECNs.

  14. Investigation of torsional vibrations in thick walled hollow poroelastic ...

    Indian Academy of Sciences (India)

    presence of dissipation which involves fluid shear viscosity. In the limiting case of thin shell, complex valued frequency equation is reduced to two real parts that give propagation velocity and attenuation, respectively. By neglecting the fluid shear viscosity, the problem reduces to that of classical Biot's theory (1956). The rest ...

  15. Investigation of torsional vibrations in thick walled hollow poroelastic ...

    Indian Academy of Sciences (India)

    βim βii. ) , is a non-symmetric second order matrix asso- ciated with S motion, respectively, whose elements are dimensionally equal to velocity squared. The expressions of these parameters are given in Appendix A. The notation I +i. ( i ω. ) I0 = is a 2 × 2 diagonal matrix associated with the Biot relaxation frequency i, and ρ.

  16. 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.

  17. A detailed study of intermolecular interactions, electronic and vibrational properties of the metal complex bis(uracilato)diammine copper(ii) dihydrate

    Science.gov (United States)

    Gramajo Feijoo, M.; Fernández-Liencres, M. P.; Gil, D. M.; Gómez, M. I.; Ben Altabef, A.; Navarro, A.; Tuttolomondo, M. E.

    2018-03-01

    Density Functional Theory (DFT) calculations were performed with the aim of investigating the vibrational, electronic and structural properties of [Cu(uracilato-N1)2 (NH3)2]ṡ2H2O complex. The IR and Raman spectra were recorded leading to a complete analysis of the normal modes of vibration of the metal complex. A careful study of the intermolecular interactions observed in solid state was performed by using the Hirshfeld surface analysis and their associated 2D fingerprint plots. The results indicated that the crystal packing is stabilized by Nsbnd H⋯O hydrogen bonds and π-stacking interactions. In addition, Csbnd H···π interactions were also observed. Time-dependent density functional theory (TD-DFT) calculations revealed that all the low-lying electronic states correspond to a mixture of intraligand charge transfer (ILCT) and ligand-to-metal charge transfer (LMCT) transitions. Finally, Natural Bond Orbital (NBO) and Atoms in Molecules (AIM) analysis were performed to shed light on the intermolecular interactions in the coordination sphere.

  18. Ab initio molecular orbital study on the G-selectivity of GGG triplet in copper(I)-mediated one-electron oxidation.

    Science.gov (United States)

    Yoshioka, Yasunori; Kawai, Hiroko; Sato, Tomoko; Yamaguchi, Kizashi; Saito, Isao

    2003-02-19

    The G-selectivity for Cu(I)-mediated one-electron oxidation of 5'-TG(1)G(2)G(3)-3' and 5'-CG(1)G(2)G(3)-3' has been examined by ab initio molecular orbital calculations. It was confirmed that G(1) is selectively damaged by Cu(I) ion for both 5'-TG(1)G(2)G(3)-3' and 5'-CG(1)G(2)G(3)-3', being good agreement with experimental results. The Cu(I)-mediated G(1)-selectivity is primarily due to the stability of the Cu(I)-coordinated complex, [-XG(1)G(2)G(3)-,-Cu(I)(H(2)O)(3)](+). The Cu(I) ion coordinates selectively to N7 of G(2) of 5'-G(1)G(2)G(3)-3' rather than N7 of G(1). The G(2)-selective coordination induces the G(1)-selective trap of a hole that is created by one-electron oxidation and migrates to GGG triplet. Therefore, the radical cation of G(1) is selectively created in both 5'-TG(1)G(2)G(3)-3' and 5'-CG(1)G(2)G(3)-3', giving the G(1)-selective damage of 5'-G(1)G(2)G(3)-3'.

  19. Evaluation of the f-electron rare-earth copper telluride GdCu1+xTe2 as a thermoelectric material

    Science.gov (United States)

    Vaney, J. B.; Benson, E.; Michiue, Y.; Mori, T.

    2017-11-01

    Chalcogenide compounds of composition ABX2 (with A, B, representing metal elements, X as the chalcogenide) have recently been attracting attention as thermoelectric materials. Possible magnetic enhancement of the thermoelectric properties has been proposed for electron-doped chalcopyrite CuFeS2 which exhibits large power factors at room temperature. Promising ZT values close to 1 have been reported for TmAgTe2 or YCuTe2 due to very low thermal conductivities ( 0.25 show very low thermal conductivities (0.64 W m-1 K-1 above 500 K for x = 0.25), which, together with a Seebeck coefficient above 0.2 mV K-1, allows to reach a moderate ZT value near 0.2 at 540 K. We also discuss the dependence with the Cu excess content of the transport properties and the lack of effect of the magnetic moment of Gd on the Seebeck coefficient.

  20. 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.

  1. The effect of copper pre-cleaning on graphene synthesis.

    Science.gov (United States)

    Kim, Soo Min; Hsu, Allen; Lee, Yi-Hsien; Dresselhaus, Mildred; Palacios, Tomás; Kim, Ki Kang; Kong, Jing

    2013-09-13

    Copper foil is the most common substrate to synthesize monolayer graphene by chemical vapor deposition (CVD). The surface morphology and conditions of the copper foil can be very different depending on the various suppliers or different batches. These surface properties of copper strongly affect the growth behavior of graphene, thus rendering the growth conditions irreproducible when different batches of Cu foil are used. Furthermore, the quality of the graphene is severely affected as well. In this work, we report a facile method of copper pre-cleaning to improve the graphene quality and the reproducibility of the growth process. We found that the commercial Ni etchant (based on nitric acid) or nitric acid is the most effective cleaning agent among various acidic or basic solutions. The graphene grown on thus-treated copper surfaces is very clean and mostly monolayer when observed under scanning electron microscopy (SEM) and optical imaging, as compared to the graphene grown on untreated copper foil. Different batches (but with the same catalog number) of copper foil from Alfa Aesar Company were examined to explore the effect of copper pre-cleaning; consistent growth results were obtained when pre-cleaning was used. This method overcomes a commonly encountered problem in graphene growth and could become one of the standard protocols for preparing the copper foil substrate for growing graphene or other 2D materials.

  2. The effect of copper pre-cleaning on graphene synthesis

    Science.gov (United States)

    Kim, Soo Min; Hsu, Allen; Lee, Yi-Hsien; Dresselhaus, Mildred; Palacios, Tomás; Kim, Ki Kang; Kong, Jing

    2013-09-01

    Copper foil is the most common substrate to synthesize monolayer graphene by chemical vapor deposition (CVD). The surface morphology and conditions of the copper foil can be very different depending on the various suppliers or different batches. These surface properties of copper strongly affect the growth behavior of graphene, thus rendering the growth conditions irreproducible when different batches of Cu foil are used. Furthermore, the quality of the graphene is severely affected as well. In this work, we report a facile method of copper pre-cleaning to improve the graphene quality and the reproducibility of the growth process. We found that the commercial Ni etchant (based on nitric acid) or nitric acid is the most effective cleaning agent among various acidic or basic solutions. The graphene grown on thus-treated copper surfaces is very clean and mostly monolayer when observed under scanning electron microscopy (SEM) and optical imaging, as compared to the graphene grown on untreated copper foil. Different batches (but with the same catalog number) of copper foil from Alfa Aesar Company were examined to explore the effect of copper pre-cleaning; consistent growth results were obtained when pre-cleaning was used. This method overcomes a commonly encountered problem in graphene growth and could become one of the standard protocols for preparing the copper foil substrate for growing graphene or other 2D materials.

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

    Science.gov (United States)

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

  4. One-pot production of copper ferrite nanoparticles using a chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Naoki, E-mail: nnishida@rs.tus.ac.jp; Amagasa, Shota [Tokyo University of Science, Department of Chemistry (Japan); Kobayashi, Yoshio [The University of Electro-Communications, Department of Engineering Science (Japan); Yamada, Yasuhiro [Tokyo University of Science, Department of Chemistry (Japan)

    2016-12-15

    Copper ferrite nanoparticles were synthesized via the oxidation of precipitates obtained from the reaction of FeCl{sub 2}, CuSO{sub 4} and N{sub 2}H{sub 4} in the presence of gelatin. These copper ferrite particles were subsequently examined using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Mössbauer spectroscopy. The average size of the copper ferrite nanoparticles was less than 5 nm, and they exhibited superparamagnetic behavior as a result of their small size. The low temperature Mössbauer spectrum exhibited three sets of sextets, two corresponding to the tetrahedral and octahedral sites of the copper spinel structure and one with small hyperfine magnetic field corresponding to the surface or defects of the nanoparticles. When the ratio of copper salt was increased, the tetrahedral site became preferable for copper, and metallic copper and copper ferrite were both present in a single nanoparticle.

  5. Preparation of copper nanoparticles by radiation

    International Nuclear Information System (INIS)

    Liu Yajian; Guo Xiongbin; Li Zhaolong; Fu Junjie; Tan Yuanyuan; Zhou Xinyao; Xu Furong

    2013-01-01

    Copper nanoparticles were successfully synthesized by 60 Co-γ radiation with aqueous solution of cupric sulfate under inert nitrogen-purged conditions. Cu nanoparticles were characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), laser particle size distribution analyzer (LSPSDA) and differential scanning calorimeter (DSC) techniques, respectively. The effects of solution system, pH, additive of surfactant and absorbed doses on the particle size and its distribution as well as stored stability of Cu naoparticles were investigated. High resolution TEM pictures showed the formation of homogeneous cubic-structured copper nanoparticles with different sizes depends on the synthetic conditions. This new kind of synthesis method shows the excellent stability, which may provide an efficient way to improve the fine tuning of the structure and size of copper nanoparticles. (authors)

  6. 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

  7. 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.

  8. Canine Copper-Associated Hepatitis

    NARCIS (Netherlands)

    Dirksen, Karen|info:eu-repo/dai/nl/412424428; Fieten, Hille|info:eu-repo/dai/nl/314112596

    2017-01-01

    Copper-associated hepatitis is recognized with increasing frequency in dogs. The disease is characterized by centrolobular hepatic copper accumulation, leading to hepatitis and eventually cirrhosis. The only way to establish the diagnosis is by histologic assessment of copper distribution and copper

  9. COPPER CABLE RECYCLING TECHNOLOGY

    International Nuclear Information System (INIS)

    Chelsea Hubbard

    2001-01-01

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

  10. Copper removal using electrosterically stabilized nanocrystalline cellulose.

    Science.gov (United States)

    Sheikhi, Amir; Safari, Salman; Yang, Han; van de Ven, Theo G M

    2015-06-03

    Removal of heavy metal ions such as copper using an efficient and low-cost method with low ecological footprint is a critical process in wastewater treatment, which can be achieved in a liquid phase using nanoadsorbents such as inorganic nanoparticles. Recently, attention has turned toward developing sustainable and environmentally friendly nanoadsorbents to remove heavy metal ions from aqueous media. Electrosterically stabilized nanocrystalline cellulose (ENCC), which can be prepared from wood fibers through periodate/chlorite oxidation, has been shown to have a high charge content and colloidal stability. Here, we show that ENCC scavenges copper ions by different mechanisms depending on the ion concentration. When the Cu(II) concentration is low (C0≲200 ppm), agglomerates of starlike ENCC particles appear, which are broken into individual starlike entities by shear and Brownian motion, as evidenced by photometric dispersion analysis, dynamic light scattering, and transmission electron microscopy. On the other hand, at higher copper concentrations, the aggregate morphology changes from starlike to raftlike, which is probably due to the collapse of protruding dicarboxylic cellulose (DCC) chains and ENCC charge neutralization by copper adsorption. Such raftlike structures result from head-to-head and lateral aggregation of neutralized ENCCs as confirmed by transmission electron microscopy. As opposed to starlike aggregates, the raftlike structures grow gradually and are prone to sedimentation at copper concentrations C0≳500 ppm, which eliminates a costly separation step in wastewater treatment processes. Moreover, a copper removal capacity of ∼185 mg g(-1) was achieved thanks to the highly charged DCC polyanions protruding from ENCC. These properties along with the biorenewability make ENCC a promising candidate for wastewater treatment, in which fast, facile, and low-cost removal of heavy metal ions is desired most.

  11. EB-welding of the copper canister for the nuclear waste disposal. Final report of the development programme 1994-1997

    International Nuclear Information System (INIS)

    Aalto, H.

    1998-10-01

    During 1994-1997 Posiva Oy and Outokumpu Poricopper Oy had a joint project Development of EB-welding method for massive copper canister manufacturing. The project was part of the national technology program 'Weld 2000' and it was supported financially by Technology Development Centre (TEKES). The spent fuel from Finnish nuclear reactors is planned to be encapsulated in thick-walled copper canisters and placed deep into the bedrock. The thick copper layer of the canister provides a long time corrosion resistance and prevents deposited nuclear fuel from contact with water. The quality requirements of the copper components are high because of the designed long lifetime of the canister. The EB-welding technology has proved to be applicable method for the production of the copper canisters and the EB-welding technique is needed at least when the lids of the copper canister will be closed. There are a number of parameters in EB-welding which affect weldability. However, the effect of the welding parameters and their optimization has not been extensively studied in welding of thick copper sections using conventional high vacuum EB-welding. One aim of this development work was to extensively study effect of welding parameters on weld quality. The final objective was to minimise welding defects in the main weld and optimize slope out procedure in thick copper EB-welding. Welding of 50 mm thick copper sections was optimized using vertical and horizontal EB-welding techniques. As a result two full scale copper lids were welded to a short cylinder successfully. The resulting weld quality with optimised welding parameters was reasonable good. The optimised welding parameters for horizontal and vertical beam can be applied to the longitudinal body welds of the canister. The optimal slope out procedure for the lid closure needs some additional development work. In addition of extensive EB-welding program ultrasonic inspection and creep strength of the weld were studied. According

  12. EB-welding of the copper canister for the nuclear waste disposal. Final report of the development programme 1994-1997

    Energy Technology Data Exchange (ETDEWEB)

    Aalto, H. [Outokumpu Oy Poricopper, Pori (Finland)

    1998-10-01

    During 1994-1997 Posiva Oy and Outokumpu Poricopper Oy had a joint project Development of EB-welding method for massive copper canister manufacturing. The project was part of the national technology program `Weld 2000` and it was supported financially by Technology Development Centre (TEKES). The spent fuel from Finnish nuclear reactors is planned to be encapsulated in thick-walled copper canisters and placed deep into the bedrock. The thick copper layer of the canister provides a long time corrosion resistance and prevents deposited nuclear fuel from contact with water. The quality requirements of the copper components are high because of the designed long lifetime of the canister. The EB-welding technology has proved to be applicable method for the production of the copper canisters and the EB-welding technique is needed at least when the lids of the copper canister will be closed. There are a number of parameters in EB-welding which affect weldability. However, the effect of the welding parameters and their optimization has not been extensively studied in welding of thick copper sections using conventional high vacuum EB-welding. One aim of this development work was to extensively study effect of welding parameters on weld quality. The final objective was to minimise welding defects in the main weld and optimize slope out procedure in thick copper EB-welding. Welding of 50 mm thick copper sections was optimized using vertical and horizontal EB-welding techniques. As a result two full scale copper lids were welded to a short cylinder successfully. The resulting weld quality with optimised welding parameters was reasonable good. The optimised welding parameters for horizontal and vertical beam can be applied to the longitudinal body welds of the canister. The optimal slope out procedure for the lid closure needs some additional development work. In addition of extensive EB-welding program ultrasonic inspection and creep strength of the weld were studied. According

  13. Fabrication of Elemental Copper by Intense Pulsed Light Processing of a Copper Nitrate Hydroxide Ink.

    Science.gov (United States)

    Draper, Gabriel L; Dharmadasa, Ruvini; Staats, Meghan E; Lavery, Brandon W; Druffel, Thad

    2015-08-05

    Printed electronics and renewable energy technologies have shown a growing demand for scalable copper and copper precursor inks. An alternative copper precursor ink of copper nitrate hydroxide, Cu2(OH)3NO3, was aqueously synthesized under ambient conditions with copper nitrate and potassium hydroxide reagents. Films were deposited by screen-printing and subsequently processed with intense pulsed light. The Cu2(OH)3NO3 quickly transformed in less than 100 s using 40 (2 ms, 12.8 J cm(-2)) pulses into CuO. At higher energy densities, the sintering improved the bulk film quality. The direct formation of Cu from the Cu2(OH)3NO3 requires a reducing agent; therefore, fructose and glucose were added to the inks. Rather than oxidizing, the thermal decomposition of the sugars led to a reducing environment and direct conversion of the films into elemental copper. The chemical and physical transformations were studied with XRD, SEM, FTIR and UV-vis.

  14. Preparation of copper and silicon/copper powders by a gas ...

    Indian Academy of Sciences (India)

    Administrator

    carrier gas and precipitated as spherical Cu metal and Si/Cu composite powders. The mean diameter of the resulting powder was 100–200 nm. Keywords. Copper powder; Si/Cu composite particle; gas evaporation–condensation method; characteriza- tion. 1. ... important role in electronics, catalysts, resins, and ther-.

  15. The Copper(I) / Copper(II) Transition in Complexes with 8-alkylthioquinoline Based Multidentate Ligands

    Czech Academy of Sciences Publication Activity Database

    Su, Ch. Y.; Liao, S.; Wanner, M.; Fiedler, Jan; Zhang, Ch.; Kang, B. S.; Kaim, W.

    - (2003), s. 189-202 ISSN 1472-7773 R&D Projects: GA MŠk OC D15.10 Institutional research plan: CEZ:AV0Z4040901 Keywords : X-ray structure * 5-coordinate copper(II) complexes * electron-transfer kinetics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.023, year: 2002

  16. Corrosion studies on copper and titanium-lead canisters for nuclear waste disposal

    International Nuclear Information System (INIS)

    Ekbom, L.B.; Hannerz, K.; Henrikson, K.S.

    1980-01-01

    The Nuclear Fuel Safety Project (KBS) has proposed that spent non-processed nuclear fuel shall be disposed of by enclosing it in copper canisters or alternatively that reprocessed and vitrified waste shall be enclosed in a titanium canister with a lead lining. The canisters are to be placed in vertical drill-holes in rock, 500 m below ground and embedded in a buffer of sand and bentonite. The purpose of this arrangement is to raise several obstacles against fission products reaching the biosphere. The thick-walled canister is one of these obstacles, which is proposed to be a barrier for a considerable period of time. Corrosion is the limiting factor of the canister durability. The rate of corrosion is dependent on the amount and transport of corrosion reactants to the surface of the canister. The thermodynamic possibilities for various corrosion reactions on copper and lead under the prevailing conditions were studied, also with regard to bacterial influence. Entrapped atmospheric oxygen and sulphide in the ground water were found to be reactants of importance. The supply of oxygen and sulphide by diffusion was calculated, and hence the greatest possible corrosion. The corrosion attack may start as pitting but will penetrate into the thick metal wall at a decreasing rate. An expert group arrived at the conclusion that under given conditions the canisters will last for a very long time (hundreds of thousands of years for copper canisters). In order to verify the expected high corrosion resistance of titanium, laboratory tests have been carried out in environments, which must be considered to provide accelerated rather than simulated tests

  17. Sliding Friction of Copper

    National Research Council Canada - National Science Library

    Liu, Tung

    1963-01-01

    .... With less clean surfaces, the coefficient of friction obtained was about 0.4. Since the degree of cleanliness cannot be controlled quantitatively, the friction - load curve of sliding copper pairs in air exhibits a bifurcation characteristic...

  18. Synthesis of Nanocrystalline Cellulose Stabilized Copper Nanoparticles

    Directory of Open Access Journals (Sweden)

    Aminu Musa

    2016-01-01

    Full Text Available A chemical reduction method was employed for the synthesis of copper nanoparticles stabilized by nanocrystalline cellulose (NCC using different concentrations of copper salt in aqueous solution under atmospheric air. CuSO4·5H2O salt and hydrazine were used as metal ion precursor and reducing agent, respectively. Ascorbic acid and aqueous NaOH were also used as an antioxidant and a pH moderator, respectively. The number of CuNPs increased with increasing concentration of the precursor salt. The formation of copper nanoparticles stabilized by NCC (CuNPs@NCC was investigated by UV-visible spectroscopy (UV-vis, where the surface absorption maximum was observed at 590 nm. X-ray diffraction (XRD analysis showed that the CuNPs@NCC are of a face-centered cubic structure. Moreover, the morphology of the CuNPs@NCC was investigated using transmission electron microscope (TEM and field emission scanning electron microscope (FESEM, which showed well-dispersed CuNPs with an average particle size less than 4 nm and the shape of CuNPs was found to be spherical. Energy dispersive X-ray spectroscope (EDS also confirmed the presence of CuNPs on the NCC. The results demonstrate that the stability of CuNPs decreases with an increasing concentration of the copper ions.

  19. Preparation of ultrafine grained copper nanoparticles via immersion deposit method

    Science.gov (United States)

    Abbasi-Kesbi, Fatemeh; Rashidi, Ali Mohammad; Astinchap, Bandar

    2018-03-01

    Today, the exploration about synthesis of nanoparticles is much of interest to materials scientists. In this work, copper nanoparticles have been successfully synthesized by immersion deposit method in the absence of any stabilizing and reducing agents. Copper (II) sulfate pentahydrate as precursor salt and distilled water and Ethylene glycol as solvents were used. The copper nanoparticles were deposited on plates of low carbon steel. The effects of copper sulfate concentrations and solvent type were investigated. X-ray diffraction, scanning electron microscopy and UV-Visible spectroscopy were taken to investigate the crystallite size, crystal structure, and morphology and size distribution and the growth process of the nanoparticles of obtained Cu particles. The results indicated that the immersion deposit method is a particularly suitable method for synthesis of semispherical copper nanoparticles with the crystallites size in the range of 22 to 37 nm. By increasing the molar concentration of copper sulfate in distilled water solvent from 0.04 to 0.2 M, the average particles size is increased from 57 to 81 nm. The better size distribution of Cu nanoparticles was achieved using a lower concentration of copper sulfate. By increasing the molar concentration of copper sulfate in water solvent from 0.04 to 0.2, the location of the SPR peak has shifted from 600 to 630 nm. The finer Cu nanoparticles were formed using ethylene glycol instead water as a solvent. Also, the agglomeration and overlapping of nanoparticles in ethylene glycol were less than that of water solvent.

  20. Electron impact single ionization of copper

    Indian Academy of Sciences (India)

    Holland Publishing Company, Ams- terdam, 1969) vol. I, p. 353. [16] G Catlow and M R C McDowell, Proc. Phys. Soc. 92, 875 (1967). [17] E Clementi and C Roetti, At. Data Nucl. Data Tables 14, 217 (1974). [18] D C Griffin and M S Pindzola, ...

  1. Bioleaching of copper from electronic scrap

    OpenAIRE

    Yamane, Luciana Harue; Espinosa, Denise Crocce Romano; Tenório, Jorge Alberto Soares

    2011-01-01

    O presente trabalho investigou a influência da suplementação de ferro e da adaptação bacteriana sobre a biolixiviação de cobre de placas de circuito impresso usando a bactéria Acidithiobacillusferrooxidans-LR. Placas de circuito impresso de computadores obsoletos foram mecanicamente processadas através de cominuição seguida de separação magnética. A bactéria Acidithiobacillusferrooxidans-LR foi crescida e adaptada à presença de amostras de placas de circuito impresso cominuídas. Um estudo de ...

  2. Electron impact single ionization of copper

    Indian Academy of Sciences (India)

    Author Affiliations. L K Jha1 O P Roy2 B N Roy3. Department of Physics, L.N.T. College, Muzaffarpur 842 002, India; Department of Physics, M.S.K.B. College, Muzaffarpur 842 002, India; Professor's Colony, Aghoria Bazar, Muzaffarpur 842 002, India ...

  3. Recrystallization of deformed copper - kinetics and microstructural evolution

    DEFF Research Database (Denmark)

    Lin, Fengxiang

    The objective of this study is to investigate the recrystallization kinetics and microstructural evolution in copper deformed to high strains, including copper deformed by cold-rolling and copper deformed by dynamic plastic deformation (DPD). Various characterization techniques were used, including...... electron backscatter diffraction (EBSD), Vickers hardness test, 3D X-ray diffraction (3DXRD) and differential scanning calorimetry (DSC). For the cold-rolled samples, a series of initial parameters was investigated for their effects on the recrystallization kinetics and textures, including initial grain...

  4. Comparative Study of Electroless Copper Film on Different Self-Assembled Monolayers Modified ABS Substrate

    Directory of Open Access Journals (Sweden)

    Jiushuai Xu

    2014-04-01

    Full Text Available Copper films were grown on (3-Mercaptopropyltrimethoxysilane (MPTMS, (3-Aminopropyltriethoxysilane (APTES and 6-(3-(triethoxysilylpropylamino-1,3,5- triazine-2,4-dithiol monosodium (TES self-assembled monolayers (SAMs modified acrylonitrile-butadiene-styrene (ABS substrate via electroless copper plating. The copper films were examined using scanning electron microscopy (SEM and X-ray diffraction (XRD. Their individual deposition rate and contact angle were also investigated to compare the properties of SAMs and electroless copper films. The results indicated that the formation of copper nuclei on the TES-SAMs modified ABS substrate was faster than those on the MPTMS-SAMs and APTES-SAMs modified ABS substrate. SEM images revealed that the copper film on TES-SAM modified ABS substrate was smooth and uniform, and the density of copper nuclei was much higher. Compared with that of TES-SAMs modified resin, the coverage of copper nuclei on MPTMS and APTES modified ABS substrate was very limited and the copper particle size was too big. The adhesion property test demonstrated that all the SAMs enhanced the interfacial interaction between copper plating and ABS substrate. XRD analysis showed that the copper film deposited on SAM-modified ABS substrate had a structure with Cu(111 preferred orientation, and the copper film deposited on TES-SAMs modified ABS substrate is better than that deposited on MPTMS-SAMs or APTES-SAMs modified ABS resins in electromigrtion resistance.

  5. Crystal structures of E. coli laccase CueO at different copper concentrations

    International Nuclear Information System (INIS)

    Li Xu; Wei Zhiyi; Zhang Min; Peng Xiaohui; Yu Guangzhe; Teng Maikun; Gong Weimin

    2007-01-01

    CueO protein is a hypothetical bacterial laccase and a good laccase candidate for large scale industrial application. Four CueO crystal structures were determined at different copper concentrations. Low copper occupancy in apo-CueO and slow copper reconstitution process in CueO with exogenous copper were demonstrated. These observations well explain the copper dependence of CueO oxidase activity. Structural comparison between CueO and other three fungal laccase proteins indicates that Glu106 in CueO constitutes the primary counter-work for reconstitution of the trinuclear copper site. Mutation of Glu106 to a Phe enhanced CueO oxidation activity and supported this hypothesis. In addition, an extra α-helix from Leu351 to Gly378 covers substrate biding pocket of CueO and might compromises the electron transfer from substrate to type I copper

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-01

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

  7. Electrical conduction in composites containing copper core-copper ...

    Indian Academy of Sciences (India)

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

  8. Tolerance of Oocystis nephrocytioides to copper: intracellular distribution and extracellular complexation of copper

    International Nuclear Information System (INIS)

    Soldo, Diana; Hari, Renata; Sigg, Laura; Behra, Renata

    2005-01-01

    Several mechanisms have been proposed to explain how algae can tolerate heavy metals. In order to better understand the mechanisms determining metal tolerance, we examined the interaction of copper with two strains of the copper-tolerant green algae Oocystis nephrocytioides, isolated from algal communities differing only in copper exposure. The strains were cultured in chemically-defined media containing 0.04 μM Cu total (pCu 12.4) or 2 μM Cu total (pCu 10.6). Growth, photosynthesis rate, content of chlorophyll a and b, copper accumulation, its cellular distribution and ultrastructural localization, as well as the influence of algal growth on extracellular copper complexation were determined. Both strains had comparable growth and photosynthesis rates. The cellular content of both chlorophyll a and b was reduced, by roughly the same extent, at pCu 10.6 compared to pCu 12.4. Copper titration of the media indicated the production of copper-complexing ligands by O. nephrocytioides cultured at pCu 12.4 that increased with increased algal density during cell growth. No additional ligands were detected at pCu 10.6. Copper-complexing ligands had a conditional stability constant of K = 10 13 at pH 7.3. The intracellular concentration of copper in O. nephrocytioides was 80 μM at pCu 12.4 and increased to 7.5 mM at pCu 10.6. The proportion of intracellular Cu accumulated increased from 8% of total Cu content at pCu 12.4 to 60% at pCu 10.6. By electron spectroscopic imaging, intracellular Cu was detected in the thylakoids and the pyrenoid of O. nephrocytioides cells. The results indicate that the tolerance of O. nephrocytioides to Cu is constitutive and does not need to be induced by previous exposure to Cu. We propose that accumulation and sequestration of Cu in thylakoids and, to a lesser extent, adsorption of copper to the algal cell surface represent the most important tolerance mechanism, for O. nephrocytioides

  9. Electron self-exchange in azurin

    DEFF Research Database (Denmark)

    Mikkelsen, K V; Skov, L K; Nar, H

    1993-01-01

    Electronic coupling between the copper atoms in an azurin dimer has been calculated in this conformationally well-defined system by using many-electronic wave functions. When one of the two water molecules forming intermolecular hydrogen bonds between the copper-ligating His-117 of the two azurin...... electron transfer. The rate of electron self-exchange between two azurins has been calculated, and the result is in very good agreement with the rate found experimentally....

  10. Electron self-exchange in azurin

    DEFF Research Database (Denmark)

    Mikkelsen, K V; Skov, L K; Nar, H

    1993-01-01

    Electronic coupling between the copper atoms in an azurin dimer has been calculated in this conformationally well-defined system by using many-electronic wave functions. When one of the two water molecules forming intermolecular hydrogen bonds between the copper-ligating His-117 of the two azurins...... electron transfer. The rate of electron self-exchange between two azurins has been calculated, and the result is in very good agreement with the rate found experimentally....

  11. 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.

  12. Behaviors and mechanisms of copper adsorption on hydrolyzed polyacrylonitrile fibers.

    Science.gov (United States)

    Deng, Shubo; Bai, Renbi; Chen, J P

    2003-04-15

    Polyacrylonitrile fiber (PANF) was hydrolyzed in a solution of sodium hydroxide and the hydrolyzed polyacrylonitrile fiber (HPANF) was used as an adsorbent to remove copper ions from aqueous solution. Scanning electron microscopy (SEM) showed that the hydrolysis process made the surface of HPANF rougher than that of PANF. Fourier transform infrared (FTIR) spectroscopy revealed that the HPANF contained conjugated imine (-Cz=Nz-) sequences. Batch adsorption results indicated that the HPANF was very effective in adsorbing copper, and the adsorption equilibrium could be reached within 10-20 min. Atomic force microscopy (AFM) showed that some aggregates formed on the surface of the HPANF after copper ion adsorption and the average surface roughness (R(a)) value of the HPANF changed from 0.363 to 3.763 nm due to copper adsorption. FTIR analysis indicated that copper adsorption caused a decrease of the light adsorption intensity of the imine (-Cz=Nz-) groups at 1573 and 1406 cm(-1) wavenumbers, and X-ray photoelectron spectroscopy (XPS) showed that the binding energy (BE) of some of the nitrogen atoms in the HPANF increased to a greater value due to copper adsorption. The FTIR and XPS results suggest that the adsorption of copper ions to the HPANF is attributed to the imine groups on the surface of the HPANF.

  13. Synthesis of copper nanocolloids using a continuous flow based microreactor

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Lei, E-mail: xulei_kmust@aliyun.com [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Mechanical Engineering, University of Washington, Seattle 98195 (United States); Peng, Jinhui [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Srinivasakannan, C. [Chemical Engineering Program, The petroleum Institute, Abu Dhabi, P.O. Box 253 (United Arab Emirates); Chen, Guo [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Shen, Amy Q., E-mail: amy.shen@oist.jp [Mechanical Engineering, University of Washington, Seattle 98195 (United States); Micro/Bio/Nanofluidics Unit, Okinawa Institute of Technology Graduate University, Okinawa (Japan)

    2015-11-15

    Highlights: • The copper nanocolloidal were synthesized in a T-shaped microreactor at room temperature. • The morphology of copper nanocolloidal are spherical, and with good size distribution. • The mean particle diameter increased with decreases the NaBH{sub 4} molar concentration. • With increasing particle size, the more obvious localized surface plasmon resonance absorption. - Abstract: The copper (Cu) nanocolloids were prepared by sodium borohydride (NaBH{sub 4}) reduction of metal salt solutions in a T-shaped microreactor at room temperature. The influence of NaBH{sub 4} molar concentrations on copper particle's diameter, morphology, size distribution, and elemental compositions has been investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The ultraviolet–visible spectroscopy (UV–vis) was used to verify the chemical compounds of nanocolloids and estimate the average size of copper nanocolloids. The synthesized copper nanocolloids were uniform in size and non-oxidized. A decrease in the mean diameter of copper nanocolloids was observed with increasing NaBH{sub 4} molar concentrations. The maximum mean diameter (4.25 nm) occurred at the CuSO{sub 4}/NaBH{sub 4} molar concentration ratio of 1:2.

  14. Coping with copper

    DEFF Research Database (Denmark)

    Nunes, Ines Marques; Jacquiod, Samuel Jehan Auguste; Brejnrod, Asker Daniel

    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...

  15. and copper(II)

    Indian Academy of Sciences (India)

    Unknown

    characterization of several imidazolate-bridged binuclear copper(II) complexes have been reported 1–17. ... of the desired complex formed were collected, washed with ethanol and dried in vacuo at room temperature. .... 16. Sigel H (ed.) 1981 Metal ions in biological system (New York: Marcel Dekker) vol 13, p. 259. 17.

  16. Electron-dislocation interaction at low temperatures. Progress report

    International Nuclear Information System (INIS)

    1978-01-01

    The interaction of mobile dislocations with electrons in copper and copper alloys has shown that dislocation motion in copper, at low temperature, can be treated as an analog of an underdamped oscillator. We have also shown that the viscous drag on mobile dislocations in type II superconductors can be treated as an acoustic attenuation of an elastic wave

  17. Laser-Assisted Reduction of Highly Conductive Circuits Based on Copper Nitrate for Flexible Printed Sensors

    Science.gov (United States)

    Bai, Shi; Zhang, Shigang; Zhou, Weiping; Ma, Delong; Ma, Ying; Joshi, Pooran; Hu, Anming

    2017-10-01

    Stretchable electronic sensing devices are defining the path toward wearable electronics. High-performance flexible strain sensors attached on clothing or human skin are required for potential applications in the entertainment, health monitoring, and medical care sectors. In this work, conducting copper electrodes were fabricated on polydimethylsiloxane as sensitive stretchable microsensors by integrating laser direct writing and transfer printing approaches. The copper electrode was reduced from copper salt using laser writing rather than the general approach of printing with pre-synthesized copper or copper oxide nanoparticles. An electrical resistivity of 96 μΩ cm was achieved on 40-μm-thick Cu electrodes on flexible substrates. The motion sensing functionality successfully demonstrated a high sensitivity and mechanical robustness. This in situ fabrication method leads to a path toward electronic devices on flexible substrates.[Figure not available: see fulltext.

  18. 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.

  19. Site-Specific Reactivity of Copper Chabazite Zeolites with Nitric Oxide, Ammonia, and Oxygen

    DEFF Research Database (Denmark)

    Godiksen, Anita; Isaksen, Oliver L.; Rasmussen, Søren B.

    2018-01-01

    In-situ electron paramagnetic resonance (EPR) spectroscopy was applied to dilute copper chabazite (CHA) zeolites under gas flows relevant for the selective catalytic reduction of NO with ammonia (NH3-SCR). Under both reducing and oxidizing conditions, we observed differences in reactivity between...... differences in reactivity of copper sites has implications for the mechanistic understanding of NH3-SCR with Cu-zeolites....

  20. Catalytic Reductive Degradation of Methyl Orange Using Air Resilient Copper Nanostructures

    OpenAIRE

    Razium Ali Soomro; Ayman Nafady; Sirajuddin; Syed Tufail Hussain Sherazi; Nazar Hussain Kalwar; Mohammad Raza Shah; Keith Richard Hallam

    2015-01-01

    The study describes the application of oxidation resistant copper nanostructures as an efficient heterogeneous catalyst for the treatment of organic dye containing waste waters. Copper nanostructures were synthesized in an aqueous environment using modified surfactant assisted chemical reduction route. The synthesized nanostructures have been characterized by UV-Vis, Fourier transform infrared spectroscopy FTIR spectroscopy, Atomic force microscopy (AFM), Scanning Electron Microscopy (SEM), a...

  1. Effect of size of copper nanoparticles on its catalytic behaviour in ...

    Indian Academy of Sciences (India)

    WINTEC

    charge over iodine atom. The whole complex reacts with another molecule of iodobenzene to produce biphenyl and cuprous iodide. The electrophilic nature of copper surface obviates that when the particles are extremely small in size, the electrons are pumped into copper by the benzene π-system, which usually reduces ...

  2. Copper uptake across rainbow trout gills: mechanisms of apical entry

    DEFF Research Database (Denmark)

    Grosell, Martin Hautopp; Wood, C. M.

    2002-01-01

    Copper, Homeostasis, sodium uptake, copper/sodium interactions, gill, rainbow trout, Oncorhynchus mykiss......Copper, Homeostasis, sodium uptake, copper/sodium interactions, gill, rainbow trout, Oncorhynchus mykiss...

  3. Controlled electropolishing of copper foils at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Gi Duk; Kim, Young Woo; Moyen, Eric; Keum, Dong Hoon [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Young Hee [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); IBS Center for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Daejeon (Korea, Republic of); Department of Physics, Sungkyunkwan Advanced Institute of Nano-technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Baik, Seunghyun [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); IBS Center for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Daejeon (Korea, Republic of); Pribat, Didier, E-mail: didier53@skku.edu [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-07-01

    We have studied the electrochemical polishing of copper foils at elevated temperature, in H{sub 3}PO{sub 4} electrolytes of various concentrations. Atomic force microscopy, surface reflectance measurements as well as optical microscopy and scanning electron microscopy (including electron backscattering diffraction) have been used throughout this study to characterize the surface of the electropolished foils. We have found that copper foils electropolished at 65 °C in 2.17 M H{sub 3}PO{sub 4}, exhibited a lower surface roughness and a higher percent specular reflection, comparing with values obtained after classical electropolishing in concentrated H{sub 3}PO{sub 4} at room temperature or comparing with values obtained after chemical-mechanical polishing. This work could open up new prospects for the preparation of copper foils before the growth of high quality graphene layers.

  4. Synthesis, characterization, and antimicrobial properties of copper nanoparticles

    Science.gov (United States)

    Usman, Muhammad Sani; Zowalaty, Mohamed Ezzat El; Shameli, Kamyar; Zainuddin, Norhazlin; Salama, Mohamed; Ibrahim, Nor Azowa

    2013-01-01

    Copper nanoparticle synthesis has been gaining attention due to its availability. However, factors such as agglomeration and rapid oxidation have made it a difficult research area. In the present work, pure copper nanoparticles were prepared in the presence of a chitosan stabilizer through chemical means. The purity of the nanoparticles was authenticated using different characterization techniques, including ultraviolet visible spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The antibacterial as well as antifungal activity of the nanoparticles were investigated using several microorganisms of interest, including methicillin-resistant Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella choleraesuis, and Candida albicans. The effect of a chitosan medium on growth of the microorganism was studied, and this was found to influence growth rate. The size of the copper nanoparticles obtained was in the range of 2–350 nm, depending on the concentration of the chitosan stabilizer. PMID:24293998

  5. and copper(II)

    Indian Academy of Sciences (India)

    Unknown

    that the imidazolate-bridged complex is stable over the pH-range 7⋅15–10⋅0. .... copper(II) complex. The observed room temperature magnetic moments are around. 1⋅79 BM, in agreement with a one-spin (S = 1/2) system. 3.2 EPR studies .... (SK) thanks the Council of Scientific & Industrial Research, New Delhi for an.

  6. Copper Pyrimidine based MOFs

    Indian Academy of Sciences (India)

    Cl..Cu.. interactions but restricted ..Cu..N N..Cu interacations. Supramolecular isomers of Br and I are reported for the first time in this paper. [Cu2I(pdz)X2]. Figure S18. Self assembly of the simultaneous presence of tecton {Cu(sol)3X} and {Cu(pdz)(sol)2X} result in [Cu2I(pdz)X2]. 1. Table S3. Copper Pyrimidine based MOFs ...

  7. Adsorption of copper to different biogenic oyster shell structures

    International Nuclear Information System (INIS)

    Wu, Qiong; Chen, Jie; Clark, Malcolm; Yu, Yan

    2014-01-01

    Graphical abstract: - Highlights: • Adsorption of copper to waste oyster shell occurs rapidly at pH 5.5. • Copper adsorbs to the different structures of oyster shell at different rates. • The prismatic layer dominates copper sorption rather than the nacreous layer. • SEM analysis shows a porous open network structure to the prismatic layer. • Surface ζ-potentials establish electrostatic attraction to drive copper sorption. - Abstract: The removal of copper from solution by oyster shell powder was investigated for potential wastewater treatment uses. In particular, adsorption behavior differences between the prismatic (PP) and nacreous (NP) shell layers, and how this affects copper removal, were investigated. Experimental results indicated that copper adsorption was highly pH-dependent with optimal copper removal at pH 5.5, where the powdered whole raw shell (RP) removed up to 99.9% of the copper within 24 h at a 10 mg/L initial copper concentration. Langmuir and Freundlich models were used to analyze the isotherm PP, NP and RP data. These results showed a strong homogeneous Langmuir model for low initial copper concentrations (5–30 mg/L) to both RP and PP layer, while strong agreement with a heterogeneous Freundlich model for high initial copper concentrations (30–200 mg/L); nevertheless, a homogeneous Langmuir model provided the best fit for the more dense NP layer across the initial concentration range (5–200 mg/L). The distribution coefficient (K d ) value of PP layer for each initial concentration investigated was substantially higher than the NP layer and it was also found that the PP layer dominated the adsorption process with an adsorption capacity of 8.9 mg/g, while the adsorption capacity of the NP layer was 2.6 mg/g. These differences are believed to be because of the more porous structure of the PP layer, which was confirmed by scanning electron microscopy, infrared spectroscopy, energy-dispersive X-ray spectroscopy, and

  8. An Investigation of Low Biofouling Copper-charged Membranes

    Science.gov (United States)

    Asapu, Sunitha

    with increased biofouling resistance. The goal of this project was to develop low-biofouling nanofiltration cellulose acetate (CA) membranes through functionalization with metal chelating ligands charged with biocidal metal ions, i.e. copper ions. To this end, glycidyl methacrylate (GMA), an epoxy, was used to attach a chelating agent, iminodiacetic acid (IDA) to facilitate the charging of copper to the membrane surface. Both CA and CA-GMA membranes were cast using the phase-inversion method. The CA-GMA membranes were then charged with copper ions to make them low biofouling. Pore size distribution analysis of CA and copper charged membranes were conducted using various molecular weights of polyethylene glycol (PEG). CA and copper-charged membranes were characterized using Fourier Transform Infrared (FTIR), contact angle to measure hydrophilicity changes, and using scanning electron microscope (SEM) coupled with X-ray energy dispersive spectroscopy EDS to monitor copper leaching. Permeation experiments were conducted with distilled (DI) water, protein solutions, and synthetic brackish water containing microorganisms. The DI water permeation of the copper-charged membranes was initially lower than the CA membranes. The membranes were then subjected to bovine serum albumin (BSA) and lipase filtration. The copper-charged membranes showed higher pure water flux values for both proteins as compared to CA membranes. The rejection of BSA and lipase was the same for both the copper charged and CA membranes. The filtration with the synthetic brackish water showed that copper-charged membranes had higher flux values as compared to CA membranes, and biofouling analysis showed more bacteria on the CA membranes as compared to copper-charged membranes. Therefore, the copper-charged membranes made here have shown a potential to be used as low-biofouling membranes in the future.

  9. Ferrite and Perlite Hardening in Copper-Alloyed Steels and Irons

    Science.gov (United States)

    Bataev, I. A.; Stepanova, N. V.; Bataev, A. A.; Razumakov, A. A.

    2017-10-01

    The paper presents transmission electron microscopy (TEM) investigations of ɛ-copper formation in ferritic grains and perlitic colonies of irons and steels alloyed with copper. It is shown that copper-enriched inclusions substantially differ in size and shape. The most disperse are particles produced by decomposition of α-phase in iron due to oversaturated copper. The size of particles appeared after austenite decomposition is approximately an order of magnitude larger. After the formation of ɛ-copper particles in ɛ-phase, they incorporate both in ferrite and partially in cementite laminas during the formation of lamellar perlite. Fine particles of ɛ-copper locating inside ferritic grains and in ferritic layers in perlite, restrain the dislocation mobility and have an additional hardening effect on iron-carbon alloys.

  10. Corrosion Protection of Copper in 3% NaCl Solution by the Fabrication of Thiadiazole Monolayer.

    Science.gov (United States)

    Durainatarajan, P; Prabakaran, M; Ramesh, S; Periasamy, V

    2018-08-01

    In this study, 2-mercapto-1,3,4-thiadiazole (2-MT) self-assembled monolayer (SAM) was formed on copper electrode surface and the resulting 2-MT SAM on copper has been characterized using surface analytical techniques such as Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray (EDX) analysis, atomic force microscopy (AFM) and contact angle measurement (CA). The existence of N and S in the EDX and FT-IR analysis showed that 2-MT molecules were self-assembled on the copper through N and S by chemisorption which indicates the formation of 2-MT SAM on copper surface. Corrosion protection performance of 2-MT SAM on copper was investigated using potentiodynamic polarization studies (PDS), cyclic voltammetry (CV) and scanning electron microscopy (SEM), respectively. Analysis of both electrochemical and SEM analysis results revealed excellent corrosion protection for the copper substrate.

  11. Controlled growth of copper oxide nanostructures by atmospheric pressure micro-afterglow

    Science.gov (United States)

    Altaweel, A.; Filipič, G.; Gries, T.; Belmonte, T.

    2014-12-01

    A large variety of copper oxide nanostructures encompassing nanodots, nanowires and nanowalls, sometimes organized in ;cabbage-like; architectures, are grown locally by direct oxidation of copper thin films using the micro-afterglow of an Ar-O2 microwave plasma operating at atmospheric pressure. Morphology, structure and composition of the oxidized copper thin films are characterized by X-ray diffraction, secondary ion mass spectrometry and scanning electron microscopy. The concentric areas where each kind of nanostructures is found are defined by both their radial position with respect to the afterglow centre and by experimental conditions. A growth mechanism is proposed, based on stress-induced outward migration of copper ions. The development of stress gradients is caused by the formation of a copper oxide scale layer. If copper oxide nanowires can be grown as in thermal oxidation processes, micro-afterglow conditions offer novel nanostructures and nano-architectures.

  12. Native copper as a natural analogue for copper canisters

    International Nuclear Information System (INIS)

    Marcos, N.

    1989-12-01

    This paper discusses the occurrence of native copper as found in geological formations as a stability analogue of copper canisters that are planned to be used for the disposal of spent nuclear fuel in the Finnish bedrock. A summary of several publications on native copper occurrences is presented. The present geochemical and geohydrological conditions in which copper is met with in its metallic state show that metallic copper is stable in a wide range of temperatures. At low temperatures native copper is found to be stable where groundwater has moderate pH (about 7), low Eh (< +100 mV), and low total dissolved solids, especially chloride. Microscopical and microanalytical studies were carried out on a dozen of rock samples containing native copper. The results reveal that the metal shows no significant alteration. Only the surface of copper grains is locally coated. In the oldest samples there exist small corrosion cracks; the age of the oldest samples is over 1,000 million years. A review of several Finnish groundwater studies suggests that there are places in Finland where the geohydrological conditions are favourable for native copper stability. (orig.)

  13. Enhancement Experiment on Cementitious Activity of Copper-Mine Tailings in a Geopolymer System

    Directory of Open Access Journals (Sweden)

    Lin Yu

    2017-12-01

    Full Text Available Copper-mine tailings are the residual products after the extraction of precious copper metal from copper ores, and their storage can create numerous environmental problems. Many researchers have used copper-mine tailings for the preparation of geopolymers. This paper studies the enhancement of the cementitious activity of copper-mine tailings in geopolymer systems. First, copper-mine tailings are activated through mechanical grinding activation. Then, the mechanically activated copper-mine tailings are further processed through thermal activation and alkaline-roasting activation. The cementitious activity index of copper-mine tailings is characterized through the degree of leaching concentration of Si and Al. It was observed that the Si and Al leaching concentration of mechanically activated tailings was increased by 26.03% and 93.33%, respectively. The concentration of Si and Al was increased by 54.19% and 119.92%, respectively. For alkaline-roasting activation, roasting time, temperature and the mass ratio of copper-mine tailings to NaOH (C/N ratio were evaluated through orthogonal tests, and the best condition for activation was 120 min at 600 °C with a C/N ratio of 5:1. In this study, scanning electron microscopy (SEM, X-ray diffraction (XRD and infra-red (IR analysis show that mechanical, thermal and alkaline-roasting activation could be used to improve the cementitious activity index of copper-mine tailings.

  14. Fabrication of conductive copper patterns using reactive inkjet printing followed by two-step electroless plating

    International Nuclear Information System (INIS)

    Chen, Jin-Ju; Lin, Guo-Qiang; Wang, Yan; Sowade, Enrico; Baumann, Reinhard R.; Feng, Zhe-Sheng

    2017-01-01

    Highlights: • Copper patterns were fabricated by reactive inkjet printing and two-step electroless plating. • Cu particles produced via reactive inkjet printing act as catalyst for copper electroless plating. • High conductivity can be obtained without many printing passes and high temperature sintering. • This approach can largely avoid nozzle-clogging problems. • This approach presents a potential way in the flexible printed electronics with simple process. - Abstract: A simple and low-cost process for fabricating conductive copper patterns on flexible polyimide substrates was demonstrated. Copper catalyst patterns were first produced on polyimide substrates using reactive inkjet printing of Cu (II)-bearing ink and reducing ink, and then the conductive copper patterns were generated after a two-step electroless plating procedure. The copper layers were characterized by optical microscope, SEM, XRD and EDS. Homogeneously distributed copper nanoclusters were found in the catalyst patterns. A thin copper layer with uniform particle size was formed after first-step electroless plating, and a thick copper layer of about 14.3 μm with closely packed structure and fine crystallinity was produced after second-step electroless plating. This resulting copper layer had good solderability, reliable adhesion strength and a low resistivity of 5.68 μΩ cm without any sintering process.

  15. Copper substrate as a catalyst for the oxidation of chemical vapor deposition-grown graphene

    International Nuclear Information System (INIS)

    Li, Zhiting; Zhou, Feng; Parobek, David; Shenoy, Ganesh J.; Muldoon, Patrick; Liu, Haitao

    2015-01-01

    We report the catalytic effect of copper substrate on graphene–oxygen reaction at high temperature. Previous studies showed that graphene grown on copper are mostly defect-free with strong oxidation resistance. We found that a freshly prepared copper-supported graphene sample can be completely oxidized in trace amount of oxygen (<3 ppm) at 600 °C within 2 h. Both X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) suggest that upon ambient air exposure, oxygen molecules diffuse into the space between graphene and copper, resulting in the formation of copper oxide which acts as catalytic sites for the graphene-oxygen reaction. This result has important implications for the characterization, processing, and storage of copper-supported graphene samples. - Graphical abstract: The copper substrate enhances the thermel oxidation of single-layer graphene. - Highlights: • A copper-supported graphene can be oxidized in Ar (O 2 <3 ppm, 600 °C, 2 h). • O 2 intercalates between graphene and copper upon exposure to air. • The copper foil should not be considered as an inert substrate

  16. Solution-processed copper-nickel nanowire anodes for organic solar cells

    Science.gov (United States)

    Stewart, Ian E.; Rathmell, Aaron R.; Yan, Liang; Ye, Shengrong; Flowers, Patrick F.; You, Wei; Wiley, Benjamin J.

    2014-05-01

    This work describes a process to make anodes for organic solar cells from copper-nickel nanowires with solution-phase processing. Copper nanowire films were coated from solution onto glass and made conductive by dipping them in acetic acid. Acetic acid removes the passivating oxide from the surface of copper nanowires, thereby reducing the contact resistance between nanowires to nearly the same extent as hydrogen annealing. Films of copper nanowires were made as oxidation resistant as silver nanowires under dry and humid conditions by dipping them in an electroless nickel plating solution. Organic solar cells utilizing these completely solution-processed copper-nickel nanowire films exhibited efficiencies of 4.9%.This work describes a process to make anodes for organic solar cells from copper-nickel nanowires with solution-phase processing. Copper nanowire films were coated from solution onto glass and made conductive by dipping them in acetic acid. Acetic acid removes the passivating oxide from the surface of copper nanowires, thereby reducing the contact resistance between nanowires to nearly the same extent as hydrogen annealing. Films of copper nanowires were made as oxidation resistant as silver nanowires under dry and humid conditions by dipping them in an electroless nickel plating solution. Organic solar cells utilizing these completely solution-processed copper-nickel nanowire films exhibited efficiencies of 4.9%. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr01024h

  17. Polycrystal deformation and single crystal deformation: Dislocation structure and flow stress in copper

    DEFF Research Database (Denmark)

    Huang, X.; Borrego, A.; Pantleon, W.

    2001-01-01

    The relation between the polycrystal deformation and single crystal deformation has been studied for pure polycrystalline copper deformed in tension. The dislocation microstructure has been analyzed for grains of different orientation by transmission electron microscopy (TEM) and three types...

  18. A Study on Gamma Irradiation Synthesis of Copper Nanoparticles

    International Nuclear Information System (INIS)

    Ahmad, Shahrul Izwan Bin; Ahmad, Md. Soot Bin Hj.; Radiman, Shahidan Bin

    2009-01-01

    A study on the effect of gamma radiation dose and dose rate on the yield of copper nanoparticles produced had been done. Its objective is to show the relationship between the absorbed doses with the yield of production. The copper sulphate solution is prepared with addition of ethanol as radical scavenger. Then the solution is bubbled with nitrogen for before being irradiated at different absorbed dose and dose rate. There are five different dose rates being used in this experiment. Atomic absorption spectroscopy (AAS) was used to detect directly the quantity of copper nanoparticles produced. The AAS results show positive linear relationship between the yields of copper nanoparticles with increasing absorbed dose. Yield of production show independency with dose rate at every absorbed dose. AAS result is supported with UV-Vis analysis data on the supernatant from irradiated products. Transmission electron microscope (TEM) confirms the existence of copper nanoparticles in all samples that being irradiated at absorbed dose of 100 kGy. The size of nanoparticles is range from 2 to 10 nm. Peak from the XRD analysis show the existence of pure copper.

  19. Seeding of silicon by copper ion implantation for selective electroless copper plating

    Energy Technology Data Exchange (ETDEWEB)

    Bhansali, S.; Sood, D.K.; Zmood, R.B. [Microelectronic and Materials Technology Centre, Royal Melbourne Institute of Technolgy, Melbourne, VIC (Australia)

    1993-12-31

    We report on the successful use of copper(self) ion implantation into silicon to seed the electroless plating of copper on silicon (100) surfaces. Copper ions have been implanted to doses of 5E14-6.4E16 ions/cm{sup 2} using a MEEVA ion implanter at extraction voltage of 40kV. Dose was varied in fine steps to determine the threshold dose of 2E15 Cu ions/cm{sup 2} for `seed` formation of copper films on silicon using a commercial electroless plating solution. Plated films were studied with Rutherford backscattering spectrometry, scanning electron microscopy, EDX and profilometry . The adhesion of films was measured by `scotch tape test`. The adhesion was found to improve with increasing dose. However thicker films exhibited rather poor adhesion and high internal stress. SEM results show that the films grow first as isolated islands which become larger and eventually impinge into a continuous film as the plating time is increased. (authors). 5 refs., 1 tab., 3 figs.

  20. 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.

    2007-12-01

    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.

  1. Twinning in copper deformed at high strain rates

    Indian Academy of Sciences (India)

    Abstract. Copper samples having varying microstructures were deformed at high strain rates using a split-. Hopkinson pressure bar. Transmission electron microscopy results show deformation twins present in samples that were both annealed and strained, whereas samples that were annealed and left unstrained, as well ...

  2. Thermal cycling tests of actively cooled beryllium copper joints

    Energy Technology Data Exchange (ETDEWEB)

    Roedig, M.; Duwe, R.; Linke, J.; Schuster, A.; Wiechers, B. [Forschungszentrum Juelich GmbH (Germany)

    1998-01-01

    Screening tests (steady state heating) and thermal fatigue tests with several kinds of beryllium-copper joints have been performed in an electron beam facility. Joining techniques under investigation were brazing with silver containing and silver-free braze materials, hot isostatic pressing (HIP) and diffusion bonding (hot pressing). Best thermal fatigue performance was found for the brazed samples. (author)

  3. Conductivity modeling of gas sensors based on copper ...

    African Journals Online (AJOL)

    The main objective of this work is to study the electronic conductivity of copper phthalocyanine (CuPc) thin films in presence of certain strong oxidizing gases involved in air pollution, particularly NO2, for use as gas sensor devices. To achieve this objective, the first part presents a study of the conductivity evolution of these ...

  4. Copper Doping of Zinc Oxide by Nuclear Transmutation

    Science.gov (United States)

    2014-03-27

    Semiconductor Materials . . . . . . . . . . . . . . . 68 Bibliography...magnetic semiconductor (DMS). Several publications have suggested that copper doped into ZnO will create ferromagnetic behavior that might be used to create...because its Cu2+ state has an unpaired electron which leads to a magnetic moment, but Cu, CuO and Cu2O have no ferromagnetic properties. This means that

  5. Organization of copper nanoclusters in Langmuir–Blodgett films

    Indian Academy of Sciences (India)

    Unknown

    Copper clusters; LB films; XPS. 1. Introduction. In recent years, considerable interest has arisen in the production of metallic nanoparticles and nanoparticulate films due to their unique optical (Preston and Moskovita. 1993), electronic and magnetic properties (Haruta et al. 1987). They also constitute a wide class of catalysts ...

  6. Synthesis and characterization of Eichhornia-mediated copper oxide ...

    Indian Academy of Sciences (India)

    The synthesized copper oxide nanoparticles were characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM) and Energy dispersive X-ray spectroscopy (EDX) analyses. The synthesized particles were highly stable, spherical in shape ...

  7. Organization of copper nanoclusters in Langmuir–Blodgett films

    Indian Academy of Sciences (India)

    The Langmuir–Blodgett films of ODSA formed from subphase containing copper ions were first subjected to sulphidation (S) using sodium sulphide and then hydrogenated (H) using hydrogen gas. Diffuse reflectance UV-visible spectroscopy (DIR-UV-vis), X-ray photoelectron spectroscopy (XPS) and transmission electron ...

  8. Observation of shell effects in nanowires for the noble metals copper, silver and gold

    OpenAIRE

    Mares, A. I.; van Ruitenbeek, J. M.

    2005-01-01

    We extend our previous shell effect observation in gold nanowires at room temperature under ultra high vacuum to the other two noble metals: silver and copper. Similar to gold, silver nanowires present two series of exceptionally stable diameters related to electronic and atomic shell filling. This observation is in concordance to what was previously found for alkali metal nanowires. Copper however presents only electronic shell filling. Remarkably we find that shell structure survives under ...

  9. Biofabrication of copper oxide nanoparticles using Andean blackberry (Rubus glaucus Benth.) fruit and leaf

    OpenAIRE

    Brajesh Kumar; Kumari Smita; Luis Cumbal; Alexis Debut; Yolanda Angulo

    2017-01-01

    Biofabrication of copper oxide nanoparticles (CuO-NPs) of a desired size remains a significant challenge. In this report, CuO-NPs were fabricated by treating 10 mM copper nitrate with Andean blackberry fruit (ABF) and leaf (ABL); and evaluated its antioxidant activity. As-prepared NPs characterization were determined by UV–visible spectrophotometry, Dynamic Light Scattering (DLS), transmission electron microscopy (TEM) with selected area electron diffraction (SAED) and X-ray diffraction (XRD)...

  10. Anticancer activity of Ficus religiosa engineered copper oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sankar, Renu; Maheswari, Ramasamy; Karthik, Selvaraju [Department of Biochemistry, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu (India); Shivashangari, Kanchi Subramanian, E-mail: shivashangari@gmail.com [Regional Forensic Science Laboratory, Tiruchirapalli, Tamilnadu (India); Ravikumar, Vilwanathan, E-mail: ravikumarbdu@gmail.com [Department of Biochemistry, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu (India)

    2014-11-01

    The design, synthesis, characterization and application of biologically synthesized nanomaterials have become a vital branch of nanotechnology. There is a budding need to develop a method for environmentally benign metal nanoparticle synthesis, that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on an eco-friendly process for rapid synthesis of copper oxide nanoparticles using Ficus religiosa leaf extract as reducing and protecting agent. The synthesized copper oxide nanoparticles were confirmed by UV–vis spectrophotometer, absorbance peaks at 285 nm. The copper oxide nanoparticles were analyzed with field emission-scanning electron microscope (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD) spectrum. The FE-SEM and DLS analyses exposed that copper oxide nanoparticles are spherical in shape with an average particle size of 577 nm. FT-IR spectral analysis elucidates the occurrence of biomolecules required for the reduction of copper oxide ions. Zeta potential studies showed that the surface charge of the formed nanoparticles was highly negative. The XRD pattern revealed that synthesized nanoparticles are crystalline in nature. Further, biological activities of the synthesized nanoparticles were confirmed based on its stable anti-cancer effects. The apoptotic effect of copper oxide nanoparticles is mediated by the generation of reactive oxygen species (ROS) involving the disruption of mitochondrial membrane potential (Δψm) in A549 cells. The observed characteristics and results obtained in our in vitro assays suggest that the copper nanoparticles might be a potential anticancer agent. - Highlights: • Biogenic synthesis of copper oxide nanoparticles by leaf extract of Ficus religiosa • Characterized via UV–vis, FT-IR, DLS, FE-SEM with EDAX and XRD • Protein may act as an encapsulating, reducing and stabilizing

  11. Anticancer activity of Ficus religiosa engineered copper oxide nanoparticles

    International Nuclear Information System (INIS)

    Sankar, Renu; Maheswari, Ramasamy; Karthik, Selvaraju; Shivashangari, Kanchi Subramanian; Ravikumar, Vilwanathan

    2014-01-01

    The design, synthesis, characterization and application of biologically synthesized nanomaterials have become a vital branch of nanotechnology. There is a budding need to develop a method for environmentally benign metal nanoparticle synthesis, that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on an eco-friendly process for rapid synthesis of copper oxide nanoparticles using Ficus religiosa leaf extract as reducing and protecting agent. The synthesized copper oxide nanoparticles were confirmed by UV–vis spectrophotometer, absorbance peaks at 285 nm. The copper oxide nanoparticles were analyzed with field emission-scanning electron microscope (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD) spectrum. The FE-SEM and DLS analyses exposed that copper oxide nanoparticles are spherical in shape with an average particle size of 577 nm. FT-IR spectral analysis elucidates the occurrence of biomolecules required for the reduction of copper oxide ions. Zeta potential studies showed that the surface charge of the formed nanoparticles was highly negative. The XRD pattern revealed that synthesized nanoparticles are crystalline in nature. Further, biological activities of the synthesized nanoparticles were confirmed based on its stable anti-cancer effects. The apoptotic effect of copper oxide nanoparticles is mediated by the generation of reactive oxygen species (ROS) involving the disruption of mitochondrial membrane potential (Δψm) in A549 cells. The observed characteristics and results obtained in our in vitro assays suggest that the copper nanoparticles might be a potential anticancer agent. - Highlights: • Biogenic synthesis of copper oxide nanoparticles by leaf extract of Ficus religiosa • Characterized via UV–vis, FT-IR, DLS, FE-SEM with EDAX and XRD • Protein may act as an encapsulating, reducing and stabilizing

  12. A study, using copper-64, of various aspects of the retention of copper supplied via the plant leaf

    International Nuclear Information System (INIS)

    Jourdan, J.; Bougie, B.; Chamel, A.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

    1976-01-01

    Copper deposited in solution or in suspension on the surface of leaves is rapidly taken up by the plant; however, this uptake process ceases almost completely a few hours after application if the aqueous phase disappears. The amount of copper taken up by the plant increases with the copper concentration of the liquid applied. The uptake does not vary significantly as between nitrate and acetate, but is distinctly less with sulphate. It is only slightly affected by the choice of surfactant, although tween 80 has proved least efficient. The most satisfactory concentrations are 0.5 vol.% for vatsol and 0.1 vol.% for tween 20. The method of application of a given volume of liquid, in the form of one or several droplets, significantly affected the uptake in one experiment out of three. The greater part of the copper taken up by the plant (generally 85 to over 99%) is located in the part treated. By examining the deposition site with a scanning electron microscope, extracting the epicuticular wax, and studying the localization of the copper by secondary ion emission in the lamina treated, it was possible to show (with the help of acetate and oxide) that a large fraction of the copper fixed by the plant remains localized on the surface at least during the first 24 hours after deposition. (author)

  13. Nanocarbon-copper thin film as transparent electrode

    International Nuclear Information System (INIS)

    Isaacs, R. A.; Zhu, H.; Preston, Colin; LeMieux, M.; Jaim, H. M. Iftekhar; Hu, L.; Salamanca-Riba, L. G.; Mansour, A.; Zavalij, P. Y.; Rabin, O.

    2015-01-01

    Researchers seeking to enhance the properties of metals have long pursued incorporating carbon in the metallic host lattice in order to combine the strongly bonded electrons in the metal lattice that yield high ampacity and the free electrons available in carbon nanostructures that give rise to high conductivity. The incorporation of carbon nanostructures into the copper lattice has the potential to improve the current density of copper to meet the ever-increasing demands of nanoelectronic devices. We report on the structure and properties of carbon incorporated in concentrations up to 5 wt. % (∼22 at. %) into the crystal structure of copper. Carbon nanoparticles of 5 nm–200 nm in diameter in an interconnecting carbon matrix are formed within the bulk Cu samples. The carbon does not phase separate after subsequent melting and re-solidification despite the absence of a predicted solid solution at such concentrations in the C-Cu binary phase diagram. This material, so-called, Cu covetic, makes deposition of Cu films containing carbon with similar microstructure to the metal possible. Copper covetic films exhibit greater transparency, higher conductivity, and resistance to oxidation than pure copper films of the same thickness, making them a suitable choice for transparent conductors

  14. Bond-length fluctuations in the copper oxide superconductors

    CERN Document Server

    Goodenough, J B

    2003-01-01

    Superconductivity in the copper oxides occurs at a crossover from localized to itinerant electronic behaviour, a transition that is first order. A spinodal phase segregation is normally accomplished by atomic diffusion; but where it occurs at too low a temperature for atomic diffusion, it may be realized by cooperative atomic displacements. Locally cooperative, fluctuating atomic displacements may stabilize a distinguishable phase lying between a localized-electron phase and a Fermi-liquid phase; this intermediate phase exhibits quantum-critical-point behaviour with strong electron-lattice interactions making charge transport vibronic. Ordering of the bond-length fluctuations at lower temperatures would normally stabilize a charge-density wave (CDW), which suppresses superconductivity. It is argued that in the copper oxide superconductors, crossover occurs at an optimal doping concentration for the formation of ordered two-electron/two-hole bosonic bags of spin S = 0 in a matrix of localized spins; the correl...

  15. 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.

  16. Spectrographic determination of impurities in copper and copper oxide

    International Nuclear Information System (INIS)

    Sabato, S.F.; Lordello, A.R.

    1990-11-01

    An emission spectrographic method for the determination of Al, Bi, Ca, Cd, Cr, Fe, Ge, Mg, Mn, Mo, Ni, Pb, Sb, Si, Sn and Zn in copper and copper oxide is described. Two mixtures (Graphite and ZnO: graphite and GeO sub(2)) were used as buffers. The standard deviation lies around 10%. (author)

  17. Physical state of implanted W in copper

    International Nuclear Information System (INIS)

    Borders, J.A.; Cullis, A.G.; Poate, J.M.

    1975-01-01

    Transmission electron microscopy and 4 He ion channeling measurements were combined to investigate the physical state of implanted W in copper. For 60 0 K implantations of 2 x 10 15 W cm -2 , W is found to be 100 percent substitutional and is still 90 percent substitutional for a dose of 10 16 W cm -2 . Implantation of 10 17 W cm -2 produces a thin disordered surface layer of W and Cu with the W occupying no regular lattice site. On annealing to 600 0 C, W precipitates are formed with dimensions of a few hundred A and certain preferred orientations in the Cu lattice. (auth)

  18. Guided design of copper oxysulfide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Chuck-Hou; Birol, Turan; Kotliar, Gabriel

    2015-07-01

    We describe a framework for designing novel materials, combining modern first-principles electronic-structure tools, materials databases, and evolutionary algorithms capable of exploring large configurational spaces. Guided by the chemical principles introduced by Antipov et al., for the design and synthesis of the Hg-based high-temperature superconductors, we apply our framework to screen 333 proposed compositions to design a new layered copper oxysulfide, Hg(CaS)2CuO2. We evaluate the prospects of superconductivity in this oxysulfide using theories based on charge-transfer energies, orbital distillation and uniaxial strain.

  19. Durable and Washable Antibacterial Copper Nanoparticles Bridged by Surface Grafting Polymer Brushes on Cotton and Polymeric Materials

    Directory of Open Access Journals (Sweden)

    Chufeng Sun

    2018-01-01

    Full Text Available To increase the durability of antibacterial coating on cotton and polymeric substrates, surface initiated grafting polymer brushes are introduced onto the substrates surface to bridge copper nanoparticles coatings and substrate. The morphologies of the composites consisting of the copper nanoparticles and polymer brushes were characterized with scanning electron microscopy (SEM. It was found that copper nanoparticles were uniformly and firmly distributed on the surfaces of the substrates by the polymer brushes; meanwhile, the reinforced concrete-like structures were formed in the composite materials. The substrates coated by the copper nanoparticles showed the efficient antibacterial activity against Staphylococcus aureus (S. aureus and Escherichia coli (E. coli even after washing by 30 cycles. The copper nanoparticles were tethered on the substrates by the strong chemical bonds, which led to the excellent washable fitness and durability. The change of the phase structure of the copper was analyzed to investigate the release mechanism of copper ions.

  20. 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

  1. Phototunable Magnetism in Copper Octacyanomolybdate

    Directory of Open Access Journals (Sweden)

    Jun Ohara

    2014-01-01

    Full Text Available We introduce copper molybdenum cyanides of general formula Cu2[Mo(CN8]·nH2O, which can serve as optofunctional magnetic devices. Their ground states generally stay paramagnetic down to temperatures of the K order but exhibit a spontaneous magnetization upon photoirradiation usually below a few tens of K. To interest us still further, such a ferromagnetic stateinduced by blue-laser irradiation is demagnetized step by step through further application of red or near-infrared laser pulses. We solve this intriguing photomagnetism. The ground-state properties are fully revealed by means of a group-theoretical technique. Taking account of experimental observations, we simulate applying pump laser pulses to a likely ground state and successfully reproduce both the magnetization and demagnetization dynamics. We monitor the photorelaxation process through angle-resolved photoemission spectroscopy. Electrons are fully itinerant in any of the photoinduced steady states, forming a striking contrast to the initial equilibrium state of atomic aspect. The fully demagnetized final steady state looks completely different from the initial paramagnetism but bears good analogy to one of the possible ground states available with the Coulomb repulsion on Cu sites suppressed.

  2. Distribution and chemical forms of copper in the root cells of castor seedlings and their tolerance to copper phytotoxicity in hydroponic culture.

    Science.gov (United States)

    Kang, Wei; Bao, Jianguo; Zheng, Jin; Hu, Hongqin; Du, Jiangkun

    2015-05-01

    The subcellular localization and chemical forms of copper in castor (Ricinus communis L.) seedlings grown in hydroponic nutrient solution were identified by chemical extraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The wild castor seeds were harvested from an abandoned copper mine in Tonglu Mountain, Daye City of Hubei Province, China. The results revealed that (1) the seedlings grew naturally in MS liquid medium with 40.00 mg kg(-1) CuSO4, in which the seedling growth rate and biomass index were 0.14 and 1.23, respectively, which were the highest values among all the treatments. The copper content in castor seedlings increased along with elevated CuSO4 concentration in the medium, reaching a maximum value of 16 570.12 mg kg(-1)(DW) when exposed to 60.00 mg L(-1) CuSO4, where 91.31% of the copper was accumulated in roots. (2) The copper existed in various chemical forms in the roots of the castor seedlings. Copper of 67.66% was extracted from the components of cell walls, such as exchangeable acidic polar compounds, cellulose and lignin, protein and pectin, and less concentrated in cell cytoplasm and nuclei. (3) Furthermore, the root cell walls were thickened when the castor seedlings exposed to CuSO4, with a large amount of high-density electron bodies, attached to the thickened cell walls. In the cell walls, most copper was bound to the carboxyl (-COOH) and hydroxyl (-OH) groups of acidic polar compounds, cellulose, hemicellulose, and polysaccharides. The conclusion showed that castor exhibited a strong tolerance to copper, the copper were accumulated mainly in the root cell, the root cell walls of castor were the major location of patience and detoxification in copper stress.

  3. Copper (II) complexes with aroylhydrazones

    Indian Academy of Sciences (India)

    Copper(II) complexes with aroylhydrazones ... The coordination chemistry of copper(II) with tridentate aroylhydrazones is briefly discussed in this article. ... EPR spectroscopy and variable temperature magnetic susceptibility measurements have been used to reveal the nature of the coordination geometry and magnetic ...

  4. 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...

  5. A new route to copper nitrate hydroxide microcrystals

    International Nuclear Information System (INIS)

    Niu Haixia; Yang Qing; Tang Kaibin

    2006-01-01

    A solution evaporation route has been successfully developed for the growth of copper nitrate hydroxide microcrystals using copper nitrate solution as the starting material in the absence of any surfactants or templates. The products were characterized by X-ray diffraction (XRD), infrared (IR) spectrum, scanning electron microscopy (SEM) and thermogravimetric (TG) analysis measurements. Controlled experiments suggested that the reaction temperature and solution concentration played an important role on the formation of the products. A possible formation mechanism of the products was also proposed

  6. Investigation of Industrial Polyurethane Foams Modified with Antimicrobial Copper Nanoparticles

    Directory of Open Access Journals (Sweden)

    Maria Chiara Sportelli

    2016-07-01

    Full Text Available Antimicrobial copper nanoparticles (CuNPs were electrosynthetized and applied to the controlled impregnation of industrial polyurethane foams used as padding in the textile production or as filters for air conditioning systems. CuNP-modified materials were investigated and characterized morphologically and spectroscopically, by means of Transmission Electron Microscopy (TEM, and X-ray Photoelectron Spectroscopy (XPS. The release of copper ions in solution was studied by Electro-Thermal Atomic Absorption Spectroscopy (ETAAS. Finally, the antimicrobial activity of freshly prepared, as well as aged samples—stored for two months—was demonstrated towards different target microorganisms.

  7. Spatial Pattern of Copper Phosphate Precipitation Involves in Copper Accumulation and Resistance of UnsaturatedPseudomonas putidaCZ1 Biofilm.

    Science.gov (United States)

    Chen, Guangcun; Lin, Huirong; Chen, Xincai

    2016-12-28

    Bacterial biofilms are spatially structured communities that contain bacterial cells with a wide range of physiological states. The spatial distribution and speciation of copper in unsaturated Pseudomonas putida CZ1 biofilms that accumulated 147.0 mg copper per g dry weight were determined by transmission electron microscopy coupled with energy dispersive X-ray analysis, and micro-X-ray fluorescence microscopy coupled with micro-X-ray absorption near edge structure (micro-XANES) analysis. It was found that copper was mainly precipitated in a 75 μm thick layer as copper phosphate in the middle of the biofilm, while there were two living cell layers in the air-biofilm and biofilm-medium interfaces, respectively, distinguished from the copper precipitation layer by two interfaces. The X-ray absorption fine structure analysis of biofilm revealed that species resembling Cu₃(PO₄)₂ predominated in biofilm, followed by Cu-Citrate- and Cu-Glutathione-like species. Further analysis by micro-XANES revealed that 94.4% of copper were Cu₃(PO₄)₂-like species in the layer next to the air interface, whereas the copper species of the layer next to the medium interface were composed by 75.4% Cu₃(PO₄)₂, 10.9% Cu-Citrate-like species, and 11.2% Cu-Glutathione-like species. Thereby, it was suggested that copper was initially acquired by cells in the biofilm-air interface as a citrate complex, and then transported out and bound by out membranes of cells, released from the copper-bound membranes, and finally precipitated with phosphate in the extracellular matrix of the biofilm. These results revealed a clear spatial pattern of copper precipitation in unsaturated biofilm, which was responsible for the high copper tolerance and accumulation of the biofilm.

  8. Copper-Containing Anti-Biofilm Nanofiber Scaffolds as a Wound Dressing Material.

    Directory of Open Access Journals (Sweden)

    Jayesh J Ahire

    Full Text Available Copper particles were incorporated into nanofibers during the electrospinning of poly-D,L-lactide (PDLLA and poly(ethylene oxide (PEO. The ability of the nanofibers to prevent Pseudomonas aeruginosa PA01 and Staphylococcus aureus (strain Xen 30 to form biofilms was tested. Nanofibers containing copper particles (Cu-F were thinner (326 ± 149 nm in diameter, compared to nanofibers without copper (CF; 445 ± 93 nm in diameter. The crystalline structure of the copper particles in Cu-F was confirmed by X-ray diffraction (XRD. Copper crystals were encapsulated, but also attached to the surface of Cu-F, as shown scanning transmission electron microscopy (STEM and transmission electron microscopy (TEM, respectively. The copper particles had no effect on the thermal degradation and thermal behaviour of Cu-F, as shown by thermogravimetric analysis (TGA and differential scanning calorimeter (DSC. After 48 h in the presence of Cu-F, biofilm formation by P. aeruginosa PA01 and S. aureus Xen 30 was reduced by 41% and 50%, respectively. Reduction in biofilm formation was ascribed to copper released from the nanofibers. Copper-containing nanofibers may be incorporated into wound dressings.

  9. 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.

  10. Microstructural changes in copper-graphite-alumina nanocomposites produced by mechanical alloying.

    Science.gov (United States)

    Rodrigues, Ivan; Guedes, Mafalda; Ferro, Alberto C

    2015-02-01

    Microstructural features of nanostructured copper-matrix composites produced via high-energy milling were studied. Copper-graphite-alumina batches were planetary ball milled up to 16 h; copper-graphite batches were also prepared under the same conditions to evaluate the effect of contamination from the milling media. The microstructure of the produced materials was characterized by field emission gun scanning electron microscopy/energy-dispersive spectroscopy and related to Raman, X-ray diffraction, and particle size analysis results. Results showed that alumina was present in all milled powders. However, size reduction was effective at shorter times in the copper-graphite-alumina system. In both cases the produced powders were nanostructured, containing graphite and alumina nanoparticles homogeneously distributed in the copper matrix, especially for longer milling times and in the presence of added alumina. Copper crystallite size was significantly affected above 4 h milling; nanographite size decreased and incipient amorphization occurred. A minimum size of 15 nm was obtained for the copper crystallite copper-alumina-graphite composite powders, corresponding to 16 h of milling. Contamination from the media became more significant above 8 h. Results suggest that efficient dispersion and bonding of graphite and alumina nanoparticles in the copper matrix is achieved, envisioning high conductivity, high strength, and thermal stability.

  11. Copper nanoparticles functionalized PE: Preparation, characterization and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Reznickova, A., E-mail: alena.reznickova@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Orendac, M., E-mail: martin.orendac@upjs.sk [Faculty of Science, P.J. Safarik University, Park Angelinum 9, 04013 Kosice (Slovakia); Kolska, Z., E-mail: zdenka.kolska@seznam.cz [Faculty of Science, J.E. Purkyne University, 400 96 Usti nad Labem (Czech Republic); Cizmar, E., E-mail: erik.cizmar@upjs.sk [Faculty of Science, P.J. Safarik University, Park Angelinum 9, 04013 Kosice (Slovakia); Dendisova, M., E-mail: vyskovsm@vscht.cz [Department of Physical Chemistry, University of Chemistry and Technology Prague, 166 28 Prague 6 (Czech Republic); Svorcik, V., E-mail: vaclav.svorcik@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic)

    2016-12-30

    Highlights: • Polyethylene (PE) surface was activated by argon plasma discharge. • Copper nanoparticles were coated on polyethylene via dithiol interlayer. • Prepared samples exhibit excellent structural and magnetic properties. • Studied properties may be utilized in design and fabrication of electronic devices. - Abstract: We report grafting of copper nanoparticles (CuNP) on plasma activated high density polyethylene (HDPE) via dithiol interlayer pointing out to the structural and magnetic properties of those composites. The as-synthesized Cu nanoparticles have been characterized by high-resolution transmission electron microscopy (HRTEM/TEM) and UV–vis spectroscopy. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, energy dispersive X-ray spectroscopy (EDS), zeta potential, electron spin resonance (ESR) and SQUID magnetometry. From TEM and HRTEM analyses, it is found that the size of high purity Cu nanoparticles is (12.2 ± 5.2) nm. It was determined that in the CuNPs, the copper atoms are arranged mostly in the (111) and (200) planes. Absorption in UV–vis region by these nanoparticles is ranging from 570 to 670 nm. EDS revealed that after 1 h of grafting are Cu nanoparticles homogeneously distributed over the whole surface and after 24 h of grafting Cu nanoparticles tend to aggregate slightly. The combined investigation of magnetic properties using ESR spectrometry and SQUID magnetometry confirmed the presence of copper nanoparticles anchored on PE substrate and indicated ferromagnetic interactions.

  12. Ergothioneine prevents copper-induced oxidative damage to DNA and protein by forming a redox-inactive ergothioneine-copper complex.

    Science.gov (United States)

    Zhu, Ben-Zhan; Mao, Li; Fan, Rui-Mei; Zhu, Jun-Ge; Zhang, Ying-Nan; Wang, Jing; Kalyanaraman, Balaraman; Frei, Balz

    2011-01-14

    Ergothioneine (2-mercaptohistidine trimethylbetaine) is a naturally occurring amino acid analogue found in up to millimolar concentrations in several tissues and biological fluids. However, the biological functions of ergothioneine remain incompletely understood. In this study, we investigated the role of ergothioneine in copper-induced oxidative damage to DNA and protein, using two copper-containing systems: Cu(II) with ascorbate and Cu(II) with H(2)O(2) [0.1 mM Cu(II), 1 mM ascorbate, and 1 mM H(2)O(2)]. Oxidative damage to DNA and bovine serum albumin was measured as strand breakage and protein carbonyl formation, respectively. Ergothioneine (0.1-1.0 mM) provided strong, dose-dependent protection against oxidation of DNA and protein in both copper-containing systems. In contrast, only limited protection was observed with the purported hydroxyl radical scavengers, dimethyl sulfoxide and mannitol, even at concentrations as high as 100 mM. Ergothioneine also significantly inhibited copper-catalyzed oxidation of ascorbate and competed effectively with histidine and 1,10-phenanthroline for binding of cuprous copper, but not cupric copper, as demonstrated by UV-visible and low-temperature electron spin resonance techniques. We conclude that ergothioneine is a potent, natural sulfur-containing antioxidant that prevents copper-dependent oxidative damage to biological macromolecules by forming a redox-inactive ergothioneine-copper complex.

  13. Two-step flash light sintering of copper nanoparticle ink to remove substrate warping

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Chung-Hyeon; Joo, Sung-Jun [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Hak-Sung, E-mail: kima@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul, 133-791 (Korea, Republic of)

    2016-10-30

    Highlights: • We performed the two-step flash light sintering for copper nanoparticle ink to remove substrate warping. • 12 J/cm{sup 2} of preheating and 7 J/cm{sup 2} of main sintering energies were determined as optimum conditions to sinter the copper nanoparticle ink. • The resistivity of two-step sintered copper nanoparticle ink was 3.81 μΩ cm with 5B adhesion level, 2.3 times greater than that of bulk copper. • The two-step sintered case showed a high conductivity without any substrate warping. - Abstract: A two-step flash light sintering process was devised to reduce the warping of polymer substrates during the sintering of copper nanoparticle ink. To determine the optimum sintering conditions of the copper nanoparticle ink, the flash light irradiation conditions (pulse power, pulse number, on-time, and off-time) were varied and optimized. In order to monitor the flash light sintering process, in situ resistance and temperature monitoring of copper nanoink were conducted during the flash light sintering process. Also, a transient heat transfer analysis was performed by using the finite-element program ABAQUS to predict the temperature changes of copper nanoink and polymer substrate. The microstructures of the sintered copper nanoink films were analyzed by scanning electron microscopy. Additionally, an X-ray diffraction and Fourier transform infrared spectroscopy were used to characterize the crystal phase change of the sintered copper nanoparticles. The resulting two-step flash light sintered copper nanoink films exhibited a low resistivity (3.81 μΩ cm, 2.3 times of that of bulk copper) and 5B level of adhesion strength without warping of the polymer substrate.

  14. Unsupported single-atom-thick copper oxide monolayers

    Science.gov (United States)

    Yin, Kuibo; Zhang, Yu-Yang; Zhou, Yilong; Sun, Litao; Chisholm, Matthew F.; Pantelides, Sokrates T.; Zhou, Wu

    2017-03-01

    Oxide monolayers may present unique opportunities because of the great diversity of properties of these materials in bulk form. However, reports on oxide monolayers are still limited. Here we report the formation of single-atom-thick copper oxide layers with a square lattice both in graphene pores and on graphene substrates using aberration-corrected scanning transmission electron microscopy. First-principles calculations find that CuO is energetically stable and its calculated lattice spacing matches well with the measured value. Furthermore, free-standing copper oxide monolayers are predicted to be semiconductors with band gaps ∼3 eV. The new wide-bandgap single-atom-thick copper oxide monolayers usher a new frontier to study the highly diverse family of two-dimensional oxides and explore their properties and their potential for new applications.

  15. Copper and the Prion Protein: Methods, Structures, Function, and Disease

    Science.gov (United States)

    Millhauser, Glenn L.

    2007-05-01

    The transmissible spongiform encephalopathies (TSEs) arise from conversion of the membrane-bound prion protein from PrPC to PrPSc. Examples of the TSEs include mad cow disease, chronic wasting disease in deer and elk, scrapie in goats and sheep, and kuru and Creutzfeldt-Jakob disease in humans. Although the precise function of PrPC in healthy tissues is not known, recent research demonstrates that it binds Cu(II) in an unusual and highly conserved region of the protein termed the octarepeat domain. This review describes recent connections between copper and PrPC, with an emphasis on the electron paramagnetic resonance elucidation of the specific copper-binding sites, insights into PrPC function, and emerging connections between copper and prion disease.

  16. Anticancer activity of Ficus religiosa engineered copper oxide nanoparticles.

    Science.gov (United States)

    Sankar, Renu; Maheswari, Ramasamy; Karthik, Selvaraju; Shivashangari, Kanchi Subramanian; Ravikumar, Vilwanathan

    2014-11-01

    The design, synthesis, characterization and application of biologically synthesized nanomaterials have become a vital branch of nanotechnology. There is a budding need to develop a method for environmentally benign metal nanoparticle synthesis, that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on an eco-friendly process for rapid synthesis of copper oxide nanoparticles using Ficus religiosa leaf extract as reducing and protecting agent. The synthesized copper oxide nanoparticles were confirmed by UV-vis spectrophotometer, absorbance peaks at 285 nm. The copper oxide nanoparticles were analyzed with field emission-scanning electron microscope (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD) spectrum. The FE-SEM and DLS analyses exposed that copper oxide nanoparticles are spherical in shape with an average particle size of 577 nm. FT-IR spectral analysis elucidates the occurrence of biomolecules required for the reduction of copper oxide ions. Zeta potential studies showed that the surface charge of the formed nanoparticles was highly negative. The XRD pattern revealed that synthesized nanoparticles are crystalline in nature. Further, biological activities of the synthesized nanoparticles were confirmed based on its stable anti-cancer effects. The apoptotic effect of copper oxide nanoparticles is mediated by the generation of reactive oxygen species (ROS) involving the disruption of mitochondrial membrane potential (Δψm) in A549 cells. The observed characteristics and results obtained in our in vitro assays suggest that the copper nanoparticles might be a potential anticancer agent. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    NARCIS (Netherlands)

    Berg, G.J. van den; Goeij, J.J.M. de; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendruiks, H.F.J.

    1991-01-01

    Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (< 1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

  18. Design and performance of a high intensity copper atom beam source nozzle for use in inelastic atom--atom collision experiments

    International Nuclear Information System (INIS)

    Santavicca, D.A.

    1975-01-01

    The research was aimed at developing a neutral copper atom beam source which could be used to study the collision cross sections for electronic excitation of neutral copper atoms in collision with neutral argon atoms. Of particular interest is the excitation from the ground state to the two upper laser levels at 3.80 and 3.82 electron volts

  19. Copper complexes as 'radiation recovery' agents

    International Nuclear Information System (INIS)

    Sorenson, J.R.J.

    1989-01-01

    Copper and its compounds have been used for their remedial effects since the beginning of recorded history. As early as 3000 BC the Egyptians used copper as an antiseptic for healing wounds and to sterilise drinking water; and later, ca 1550 BC, the Ebers Papyrus reports the use of copper acetate, copper sulphate and pulverised metallic copper for the treatment of eye infections. These historical uses of copper and its compounds are particularly interesting in the light of modern evidence concerning the use of certain copper complexes for the treatment of radiation sickness and more recently as an adjunct to radiotherapy for cancer patients. (author)

  20. NID Copper Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  1. 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.

  2. Gallium and copper radiopharmaceutical chemistry

    International Nuclear Information System (INIS)

    Green, M.A.

    1991-01-01

    Gallium and copper radionuclides have a long history of use in nuclear medicine. Table 1 presents the nuclear properties of several gallium and copper isotopes that either are used in the routine practice of clinical nuclear medicine or exhibit particular characteristics that might make them useful in diagnostic or therapeutic medicine. This paper will provide some historic perspective along with an overview of some current research directions in gallium and copper radiopharmaceutical chemistry. A more extensive review of gallium radiopharmaceutical chemistry has recently appeared and can be consulted for a more in-depth treatment of this topic

  3. Synthesis of Copper Nanoparticles by Thermal Decomposition and Their Antimicrobial Properties

    Directory of Open Access Journals (Sweden)

    R. Betancourt-Galindo

    2014-01-01

    Full Text Available Copper nanoparticles were synthesized by thermal decomposition using copper chloride, sodium oleate, and phenyl ether as solvent agents. The formation of nanoparticles was evidenced by the X-ray diffraction and transmission electron microscopy. The peaks in the XRD pattern correspond to the standard values of the face centered cubic (fcc structure of metallic copper and no peaks of other impurity crystalline phases were detected. TEM analysis showed spherical nanoparticles with sizes in the range of 4 to 18 nm. The antibacterial properties of copper nanoparticles were evaluated in vitro against strains of Staphylococcus aureus and Pseudomonas aeruginosa. The antibacterial activity of copper nanoparticles synthesized by thermal decomposition showed significant inhibitory effect against these highly multidrug-resistant bacterial strains.

  4. Copper nitride thin film prepared by reactive radio-frequency magnetron sputtering

    International Nuclear Information System (INIS)

    Yue, G.H.; Yan, P.X.; Liu, J.Z.; Wang, M.X.; Li, M.; Yuan, X.M.

    2005-01-01

    Copper nitride (Cu 3 N) thin films were deposited on glass substrates by reactive radio-frequency magnetron sputtering of a pure copper target in a nitrogen/argon atmosphere. The deposition rate of the films gradually decreased with increasing nitrogen flow rate. The color of the deposited films was a reddish dark brown. The Cu 3 N films obtained by this method were strongly textured with crystal direction [100]. The grain size of the polycrystalline films ranged from 16 to 26 nm. The Hall effect of the copper nitride (Cu 3 N) thin films was investigated. The optical energy gap of the films was obtained from the Hall coefficient and found to vary with the nitrogen content. The surface morphology was studied by scanning electron microscopy and atomic force microscopy. The copper nitride thin films are unstable and decompose into nitrogen and copper upon heat treatment when annealed in vacuum with argon protected at 200 deg. C for 1 h

  5. Corrosion behavior of copper-base materials in a gamma-irradiated environment; Final report

    Energy Technology Data Exchange (ETDEWEB)

    Yunker, W.H.

    1990-09-01

    Specimens of three copper-base materials were corrosion tested with gamma radiation exposure dose rates in the range of 1.9 {times} 10{sup 3} R/h to 4.9 {times} 10{sup 5} R/h. Materials used were pure copper, 7% aluminum bronze and 30% copper-nickel. Exposures were performed in moist air at 95{degree}C and 150{degree}C and liquid Well J-13 water at 95{degree}C, for periods of up to 16 months. Specimens were monitored for uniform weight loss, stress-induced corrosion and crevice corrosion. Specimen surfaces were examined visually at 10X magnification as well as by Auger Electron Spectroscopy, x-ray diffraction and metallography. Corrosion was not severe in any of the cases. In general, the pure copper was corroded most uniformly while the copper-nickel was the least reproducibly corroded. 11 refs, 40 figs., 15 tabs.

  6. Corrosion behavior of copper-base materials in a gamma-irradiated environment

    International Nuclear Information System (INIS)

    Yunker, W.H.

    1990-09-01

    Specimens of three copper-base materials were corrosion tested with gamma radiation exposure dose rates in the range of 1.9 x 10 3 R/h to 4.9 x 10 5 R/h. Materials used were pure copper, 7% aluminum bronze and 30% copper-nickel. Exposures were performed in moist air at 95 degree C and 150 degree C and liquid Well J-13 water at 95 degree C, for periods of up to 16 months. Specimens were monitored for uniform weight loss, stress-induced corrosion and crevice corrosion. Specimen surfaces were examined visually at 10X magnification as well as by Auger Electron Spectroscopy, x-ray diffraction and metallography. Corrosion was not severe in any of the cases. In general, the pure copper was corroded most uniformly while the copper-nickel was the least reproducibly corroded. 11 refs, 40 figs., 15 tabs

  7. Modification of polycrystalline copper by proton irradiation; Modificacion de cobre policristalino por irradiacion con protones

    Energy Technology Data Exchange (ETDEWEB)

    Garcia S, F.; Cabral P, A. [Instituto Nacional de Investigaciones Nucleares, Hipodromo Condesa, 06100 Mexico D.F. (Mexico); Saniger B, J.M.; Banuelos, J.G. [UNAM Centro de Instrumentos, Mexico D.F. (Mexico); Barragan V, A. [UNAM Instituto de Fisica, Mexico D.F. (Mexico)

    1997-07-01

    Polished copper samples were irradiated with proton beams of 300 and 700 keV at room temperature and at -150 Centigrade. In this work the obtained results are reported when such copper irradiated samples are analysed with Sem, Tem, AFM. The Sem micrographs showed evident changes in surface of these copper samples, therefore an EDAX microanalysis was done for its characterization. additionally, the Tem micrographs showed heaps formation until 200 nm. Its electron diffraction spectra indicated that these heaps consist of a copper compound. Finally with AFM were observed changes in coloration of the irradiated sample surface, as well as changes in texture and rugosity of them. These results show in general that irradiation process with protons which is known as an innocuo process produces changes in the copper properties. (Author)

  8. Mechanical and corrosion behaviors of developed copper-based metal matrix composites

    Science.gov (United States)

    Singh, Manvandra Kumar; Gautam, Rakesh Kumar; Prakash, Rajiv; Ji, Gopal

    2018-03-01

    This work investigates mechanical properties and corrosion resistances of cast copper-tungsten carbide (WC) metal matrix composites (MMCs). Copper matrix composites have been developed by stir casting technique. Different sizes of micro and nano particles of WC particles are utilized as reinforcement to prepare two copper-based composites, however, nano size of WC particles are prepared by high-energy ball milling. XRD (X-rays diffraction) characterize the materials for involvement of different phases. The mechanical behavior of composites has been studied by Vickers hardness test and compression test; while the corrosion behavior of developed composites is investigated by electrochemical impedance spectroscopy in 0.5 M H2SO4 solutions. The results show that hardness, compressive strength and corrosion resistance of copper matrix composites are very high in comparison to that of copper matrix, which attributed to the microstructural changes occurred during composite formation. SEM (Scanning electron microscopy) reveals the morphology of the corroded surfaces.

  9. Copper sludge from printed circuit board production/recycling for ceramic materials: a quantitative analysis of copper transformation and immobilization.

    Science.gov (United States)

    Tang, Yuanyuan; Lee, Po-Heng; Shih, Kaimin

    2013-08-06

    The fast development of electronic industries and stringent requirement of recycling waste electronics have produced a large amount of metal-containing waste sludge. This study developed a waste-to-resource strategy to beneficially use such metal-containing sludge from the production and recycling processes of printed circuit board (PCBs). To observe the metal incorporation mechanisms and phase transformation processes, mixtures of copper industrial waste sludge and kaolinite-based materials (kaolinite and mullite) were fired between 650 and 1250 °C for 3 h. The different copper-hosting phases were identified by powder X-ray diffraction (XRD) in the sintered products, and CuAl2O4 was found to be the predominant hosting phase throughout the reactions, regardless of the strong reduction potential of copper expected at high temperatures. The experimental results indicated that CuAl2O4 was generated more easily and in larger quantities at low-temperature processing when using the kaolinite precursor. Maximum copper transformations reached 86% and 97% for kaolinite and mullite systems, respectively, when sintering at 1000 °C. To monitor the stabilization effect after thermal process, prolonged leaching tests were carried out using acetic acid with an initial pH value of 2.9 to leach the sintered products for 20 days. The results demonstrated the decrease of copper leachability with the formation of CuAl2O4, despite different sintering behavior in kaolinite and mullite systems. This study clearly indicates spinel formation as the most crucial metal stabilization mechanism when sintering copper sludge with aluminosilicate materials, and suggests a promising and reliable technique for reusing metal-containing sludge as ceramic materials.

  10. The anodization synthesis of copper oxide nanosheet arrays and their photoelectrochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Xia [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zheng, Hongmei [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, Hefei 230009 (China); Xu, Guangqing, E-mail: gqxu1979@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, Hefei 230009 (China); Zhao, Jiebo [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Cui, Lihua [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); School of Materials Science and Engineering, Beifang University of Nationalities, Yinchuan 750021 (China); Cui, Jiewu; Qin, Yongqiang; Wang, Yan [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zhang, Yong [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, Hefei 230009 (China); Wu, Yucheng, E-mail: ycwu@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, Hefei 230009 (China)

    2017-08-01

    Graphical abstract: Current-time and potential-time curves of the copper foil anodization process, CV of copper substrate in anodization solution and SEM morphologies of anodization products on Cu substrates obtained at different time. - Highlights: • Copper oxides nanosheet arrays were achieved via anodization method. • The growth mechanisms of the copper anodization process were studied. • Photoelectrochemical performances of copper oxides NSAs were studied. - Abstract: We studied the growth of copper oxide nanosheet arrays on copper foil via a simple anodization method. The structures, morphologies, and elemental compositions of the specimens were characterized with an X-ray diffractometer, scanning electron microscope, high resolution transmission electron microscope, and X-ray photoelectron spectrometer. The copper oxide (Cu{sub 2}O and CuO) nanosheet arrays were comprised of 30-nm-thick nanosheets that stand vertically on the Cu substrate. The anodizing parameters, such as the current density, temperature, and polyethylene glycol concentration, were optimized to obtain the regular nanosheet arrays. The optical absorption properties of the anodized products were evaluated using a diffuse reflectance spectrometer, and broad and strong optical absorption bands arising from the UV to visible region were observed. The photoelectrochemical performance of the nanosheet arrays was measured with chronoamperometry and cyclic voltammetry on an electrochemical workstation equipped with a Xe lamp (wavelength >400 nm). A negative photocurrent was obtained due to the p-type semiconductor of the copper oxides. The copper oxide nanosheet arrays achieve the highest photocurrent of 0.4 mA/cm{sup 2} at the current density of 1.0 A/dm{sup 2}, temperature of 70 °C, and polyethylene glycol concentration of 0.5 g/L.

  11. Copper tailings in stucco mortars

    Directory of Open Access Journals (Sweden)

    Osvaldo Pavez

    Full Text Available Abstract This investigation addressed the evaluation of the use of copper tailings in the construction industry in order to reduce the impact on the environment. The evaluation was performed by a technical comparison between stucco mortars prepared with crushed conventional sand and with copper tailings sand. The best results were achieved with the stucco mortars containing tailings. The tailings presented a fine particles size distribution curve different from that suggested by the standard. The values of compressive strength, retentivity, and adherence in the stucco mortars prepared with copper tailings were much higher than those obtained with crushed sand. According to the results from this study, it can be concluded that the preparation of stucco mortars using copper tailings replacing conventional sand is a technically feasible alternative for the construction industry, presenting the benefit of mitigating the impact of disposal to the environment.

  12. Hereditary iron and copper deposition

    DEFF Research Database (Denmark)

    Aaseth, Jan; Flaten, Trond Peder; Andersen, Ole

    2007-01-01

    Hereditary deposition of iron (primary haemochromatosis) or copper (Wilson's disease) are autosomal recessive metabolic disease characterized by progressive liver pathology and subsequent involvement of various other organs. The prevalence of primary haemochromatosis is approximately 0.5%, about...

  13. Kinetic formation of silver-copper nanoparticles and its characterization

    Science.gov (United States)

    Zulkafi, Nurul Hikmah; Idrus, Nor Faeqah; Jai, Junaidah; Hadi, Abdul

    2017-12-01

    A study of the kinetic formation of silver-copper nanoparticles in aqueous medium on the basis of size distribution and its characterization has been carried out and reported in this paper. The Ag-Cu nanoparticles were synthesized through polyol method that using Ethylene Glycol (H2C6O12) as a reduction agent and solvent and Polyoxyethylene-(80)-Sorbitan Monooleate (Tween 80) as a stabilizer. The kinetic formation of Ag-Cu nanoparticles was observed using Dynamic Light Scattering (DLS) and characterized by using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and Transmission Electron Microscope (TEM). The XRD analysis results confirmed that size distribution was strongly dependent on molarity of precursors of silver (AgNO3) and copper (Cu(NO3)2.3H2O). The FESEM and TEM analysis indicated the existence of Ag and Cu nanoparticles in the core-shell shape. The silver-copper nanoparticles were spherical and uniform particles size with the average size of about 28 nm and 38 nm for silver and copper, respectively. DLS observation showed the growth of nanoparticles at the temperature of 140°C as the effect of reaction time at 1, 2, 3, 4 and 5 hours.

  14. The copper deposits of Michigan

    Science.gov (United States)

    Butler, B.S.; Burbank, W.S.

    1929-01-01

    The copper district of Keweenaw Point, in the northern peninsula of Michigan, is the second largest producer of copper in the world.  The output of the district since 1845 has been more than 7,500,000,000 pounds and showed a rather steady and consistent increase from the beginning of production to the end of the World War in 1918, since which there has been a marked decrease.

  15. Atmospheric corrosion effects on copper

    International Nuclear Information System (INIS)

    Franey, J.P.

    1985-01-01

    Studies have been performed on the naturally formed patina on various copper samples. Samples have been obtained from structures at AT and T Bell Laboratories, Murray Hill, NJ (40,2,1 and <1 yr) and the Statue of Liberty (100 yr). The samples show a distinct layering effect, that is, the copper base material shows separate oxide and basic sulfate layers on all samples, indicating that patina is not a homogeneous mixture of oxides and basic sulfates

  16. Investigation of Copper Ammonia Leaching from Smelter Slags: Characterization, Leaching and Kinetics

    Science.gov (United States)

    Bidari, Ehsan; Aghazadeh, Valeh

    2015-10-01

    Although ammonia leaching of copper from slags has been reported generally as a part of copper slag utilization methods, but no detailed studies have been reported in the literature. In this research, we tried to investigate the effect of different parameters on ammonia leaching of copper from copper smelting slag by identifying different copper-bearing phases and following them during leaching time. Mineralogical characterization of the smelting slag (1.7 pct Cu) was done using X-ray fluorescence, X-ray diffraction, optical microscopy, diagnostic leaching tests, and scanning electron microscopy. The characterization studies indicated that main copper-bearing species are soluble copper oxides and chalcocite along with minor amount of covellite, bornite, blister copper particles, and chalcopyrite. It was also found that only approximately 0.2 pct Cu was present in the insoluble bulk silicate phases. These results suggest that approximately 88 pct of the total copper of slag could be extracted by ammonia sulfide leaching. Leaching tests were carried out and the effects of various parameters, namely pH, ammonia concentration, temperature, presence of oxygen, stirring speed, and pulp density were examined on copper leaching. The temperature and stirring speed had the most pronounced effect on the copper leaching, whereas ammonia affected the leaching yield at low concentrations of ammonia. It was found that 78 pct of Cu could be extracted within 4 hours and under optimum conditions: T = 343 K (70 °C), 2M ammonia, pH 10.5, stirring speed = 900 rpm, pulp density = 10 pct ( w s/ v). The kinetic data were analyzed with the shrinking core models, and it was found that the leaching process is controlled by both the interfacial transfer and diffusion across the product layer and the activation energy is calculated to be 49.4 kJ mol-1.

  17. 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....

  18. A Facile Fabrication of Silver-Coated Copper Nanowires by Galvanic Replacement

    Directory of Open Access Journals (Sweden)

    Xin He

    2016-01-01

    Full Text Available We demonstrated a general strategy to fabricate silver-coated copper nanowires by a galvanic replacement, which is guided by the chemical principle that metal ions (silver ions with a relatively high reduction potential can galvanically etch nanostructure made from a less metal (copper. Well-dispersed and high-yielded copper nanowires were initially synthesized and then introduced into silver-ammonia solution for the growth of silver nanocrystals on the nanowire surfaces under vigorous oscillation. The results of X-ray diffraction, scanning electron microscope, and transmission electron microscope revealed that the silver nanocrystals were uniformly distributed on the copper nanowire surfaces to form Cu-Ag heterostructures. The concentration of silver-ammonia solution and the time of replacement reaction determine the size and density of the silver nanocrystals. Our investigation might pave the way to the synthesis of other bimetallic nanostructures via a facile, fast, and economical route.

  19. Copper vertical micro dendrite fin arrays and their superior boiling heat transfer capability

    Science.gov (United States)

    Wang, Ya-Qiao; Lyu, Shu-Shen; Luo, Jia-Li; Luo, Zhi-Yong; Fu, Yuan-Xiang; Heng, Yi; Zhang, Jian-Hui; Mo, Dong-Chuan

    2017-11-01

    Micro pin fin arrays have been widely used in electronic cooling, micro reactors, catalyst support, and wettability modification and so on, and a facile way to produce better micro pin fin arrays is demanded. Herein, a simple electrochemical method has been developed to fabricate copper vertical micro dendrite fin arrays (Cu-VMDFA) with controllable shapes, number density and height. High copper sulphate concentration is one key point to make the dendrite stand vertically. Besides, the applied current should rise at an appropriate rate to ensure the copper dendrite can grow vertically on its own. The Cu-VMDFA can significantly enhance the heat transfer coefficient by approximately twice compared to the plain copper surface. The Cu-VMDFA may be widely used in boiling heat transfer areas such as nuclear power plants, electronic cooling, heat exchangers, and so on.

  20. Tunable copper microstructures in blanket films and trenches using pulsed electrodeposition

    Science.gov (United States)

    Marro, James

    Copper interconnects in microelectronics have long been plagued with thermo-mechanical reliability issues. Control over the copper deposition process and resulting microstructure can dictate its material properties and reduce stresses as well as defects that form in the copper. In this thesis, pulse electrodeposition processing parameters were evaluated for their impact on the copper microstructure (grain size, texture, and twin density and stress state) through electron backscattering diffraction and wafer curvature measurements. Varying levels of constraint were also investigated for their effect on the copper microstructure to better understand the microstructures of more complex three-dimensional interconnects. Highly texture blanket copper films were deposited with various pulse frequencies and duty cycle, which was found to control grain size, orientation, and twin density. Higher twin densities were also observed in the films with lower residual stress. The findings from blanket film studies were carried over to trench deposited samples, where the influence of organic additives, typically used in the electrolytic bath to produce defect-free filling of advanced geometries, on the copper microstructure was studied. With the addition of organic additives, depositions produced finer grained structures with an increased contribution from the microstructure of the trench sidewall seed layer, especially with increasing trench aspect ratio. In addition, the increased constraint of the copper, resulted in larger stresses within the features and higher twin densities. The core of this dissertation demonstrated the ability to alter the resulting Cu microstructure through variations in pulse electrodeposition parameters.

  1. Green synthesis of colloidal copper oxide nanoparticles using Carica papaya and its application in photocatalytic dye degradation

    Science.gov (United States)

    Sankar, Renu; Manikandan, Perumal; Malarvizhi, Viswanathan; Fathima, Tajudeennasrin; Shivashangari, Kanchi Subramanian; Ravikumar, Vilwanathan

    2014-03-01

    Copper oxide (CuO) nanoparticles were synthesized by treating 5 mM cupric sulphate with Carica papaya leaves extract. The kinetics of the reaction was studied using UV-visible spectrophotometry. An intense surface Plasmon resonance between 250-300 nm in the UV-vis spectrum clearly reveals the formation of copper oxide nanoparticles. The results of scanning electron microscopy (SEM) and dynamic light scattering (DLS) exhibited that the green synthesized copper oxide nanoparticles are rod in shape and having a mean particle size of 140 nm, further negative zeta potential disclose its stability at -28.9 mV. The Fourier-transform infrared (FTIR) spectroscopy results examined the occurrence of bioactive functional groups required for the reduction of copper ions. X-ray diffraction (XRD) spectra confirmed the copper oxide nanoparticles crystalline nature. Furthermore, colloidal copper oxide nanoparticles effectively degrade the Coomassie brilliant blue R-250 dye beneath the sunlight.

  2. Severe corrosion of copper in a highly alkaline egg white solution due to a biuret corrosion reaction

    International Nuclear Information System (INIS)

    Liu, Xun; Hu, Wenyuan; Yang, Shan; Li, Zhaoqian; Pei, Chonghua; Zhou, Yong; Yin, Guanfu

    2015-01-01

    Highlights: • Egg whites can accelerate the corrosion of copper. • The corrosion rate of copper is closely related to the pH values. • The mechanism of the strong corrosion is due to a biuret corrosion reaction. - Abstract: Through investigating the interaction between copper metal and egg whites as well as the effects of pH, oxygen and the species of alkalis on copper corrosion rate, an unusual severe corrosion of copper metal in a highly alkaline egg white solution was found. The mechanism was investigated through detailed characterizations using a scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy and UV–visible absorption spectroscopy. The severe corrosion was mainly due to the formation of a hydroxyl–peptide–copper multicomponent stable soluble complex, which the biuret reaction also produces

  3. Use of copper radioisotopes in investigating disorders of copper metabolism

    International Nuclear Information System (INIS)

    Camakaris, J.; Voskoboinik, I.; Brooks, H.; Greenough, M.; Smith, S.; Mercer, J.

    1998-01-01

    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 64 Cu (t 1/2 = 12.8 hr) and 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

  4. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    Energy Technology Data Exchange (ETDEWEB)

    Laha, Dipranjan; Pramanik, Arindam [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Laskar, Aparna [CSIR-Indian Institute of Chemical Biology, Kolkata 700032 (India); Jana, Madhurya [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Pramanik, Panchanan [Department of Chemistry, Indian Institute of Technology, Kharagpur 721302 (India); Karmakar, Parimal, E-mail: pkarmakar_28@yahoo.co.in [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India)

    2014-11-15

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain.

  5. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    International Nuclear Information System (INIS)

    Laha, Dipranjan; Pramanik, Arindam; Laskar, Aparna; Jana, Madhurya; Pramanik, Panchanan; Karmakar, Parimal

    2014-01-01

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain

  6. Novel route for rapid biosynthesis of copper nanoparticles using aqueous extract of Calotropis procera L. latex and their cytotoxicity on tumor cells.

    Science.gov (United States)

    Harne, Shrikant; Sharma, Ashwinikumar; Dhaygude, Mayur; Joglekar, Shreeram; Kodam, Kisan; Hudlikar, Manish

    2012-06-15

    This paper accounts for novel, low-cost, eco-friendly route for rapid biosynthesis of copper nanoparticles. Cysteine proteases present in the latex of Calotropis procera L. were used to fabricate copper nanoparticles from copper acetate. Copper nanoparticles were initially characterized by transmission electron microscopy (TEM) and X-ray diffraction technique (XRD). Transmission electron microscopy (TEM) was used to estimate the size and shape of nanoparticles. The average size of copper nanoparticles was found to be 15 ± 1.7 nm. Energy dispersive analysis of X-rays (EDAX) showed distinct peaks of copper. Fourier transform infrared spectroscopy (FTIR) was performed to confirm capping behavior of the latex proteins that contributed to long term stability of copper nanoparticles (6 months) in aqueous medium. Copper nanoparticles synthesized by above method were monodisperse type. Cytotoxicity studies of latex stabilized copper nanoparticles were carried out on HeLa, A549 and BHK21 cell lines by MTT dye conversion assay. HeLa, A549 and BHK21 cells showed excellent viability even at 120 μM concentration of copper nanoparticles. This shows that copper nanoparticles synthesized by above method hold excellent biocompatibility. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Effects of structural heterogeneity of nanostructured copper on the evolution of the sizes of recrystallized grains during annealing

    DEFF Research Database (Denmark)

    Lin, Fengxiang; Zhang, Yubin; Pantleon, Wolfgang

    2015-01-01

    Recrystallization in copper deformed by dynamic plastic deformation was investigated using electron backscatter diffraction. The recrystallized grains show a broad size distribution. The kinetics of grains of different sizes is observed to be different: In the beginning of recrystallization, the ...

  8. NID Copper Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01

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

  9. 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

    Copper-based multi-level metallization systems in today's ultralarge-scale integrated electronic circuits require the fabrication of diffusion barriers and conductive seed layers for the electrochemical metal deposition. Such films of only several nanometers in thickness have to be deposited void-free and conformal in patterned dielectrics. The envisaged further reduction of the geometric dimensions of the interconnect system calls for coating techniques that circumvent the drawbacks of the well-established physical vapor deposition. The atomic layer deposition method (ALD) allows depositing films on the nanometer scale conformally both on three-dimensional objects as well as on large-area substrates. The present work therefore is concerned with the development of an ALD process to grow copper oxide films based on the metal-organic precursor bis(trin- butylphosphane)copper(I)acetylacetonate [({sup n}Bu{sub 3}P){sub 2}Cu(acac)]. This liquid, non-fluorinated {beta}-diketonate is brought to react with a mixture of water vapor and oxygen at temperatures from 100 to 160 C. Typical ALD-like growth behavior arises between 100 and 130 C, depending on the respective substrate used. On tantalum nitride and silicon dioxide substrates, smooth films and selfsaturating film growth, typical for ALD, are obtained. On ruthenium substrates, positive deposition results are obtained as well. However, a considerable intermixing of the ALD copper oxide with the underlying films takes place. Tantalum substrates lead to a fast self-decomposition of the copper precursor. As a consequence, isolated nuclei or larger particles are always obtained together with continuous films. The copper oxide films grown by ALD can be reduced to copper by vapor-phase processes. If formic acid is used as the reducing agent, these processes can already be carried out at similar temperatures as the ALD, so that agglomeration of the films is largely avoided. Also for an integration with subsequent

  10. 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.

  11. Local strain distributions in partially recrystallized copper determined by in situ tensile investigation

    DEFF Research Database (Denmark)

    Lin, Fengxiang; Ubhi, H.S.; Zhang, Yubin

    2015-01-01

    A partially recrystallized copper sample produced by cold-rolling and annealing was deformed in situ by uniaxial tension in a scanning electron microscope, and electron backscatter diffraction data were collected before and after deformation to certain strains. The local strain distributions are ...

  12. Dislocations structure in copper cyclically deformed in low amplitude of deformation

    International Nuclear Information System (INIS)

    Lopes, L.C.R.

    1982-07-01

    The evolution of the dislocation structure during the fatigue life of copper, was observed. Fatigue tests were performed, in annealed polycristals, with constant plastic strain amplitude, and interrupted at different percentages of their fatigue lives. Optical and Scanning Electron Microscopy were used for surface analysis and Transmission Electron Microscopy for structural observations. (E.G.) [pt

  13. Synthesis and characterization of silver-copper core-shell nanoparticles using polyol method for antimicrobial agent

    Science.gov (United States)

    Hikmah, N.; Idrus, N. F.; Jai, J.; Hadi, A.

    2016-06-01

    Silver and copper nanoparticles are well-known as the good antimicrobial agent. The nano-size of particles influences in enhancing the antimicrobial activity. This paper discusses the effect of molarity on the microstructure and morphology of silver-copper core-shell nanoparticles prepared by a polyol method. In this study, silver-copper nanoparticles are synthesized through the green approach of polyol method using ethylene glycol (EG) as green solvent and reductant, and polyoxyethylene-(80)-sorbitan monooleate (Tween 80) as a nontoxic stabilizer. The phase and morphology of silver-copper nanoparticles are characterized by X-ray diffraction (XRD) and Field emission scanning electron microscope (FESEM) and Transmission electron microscope (TEM). The results XRD confirm the pure crystalline of silver and copper nanoparticles with face-centered cubic (FCC) structure. FESEM and TEM analysis confirm the existence of Ag and Cu nanoparticles in core-shell shape.

  14. Additive and Photochemical Manufacturing of Copper

    Science.gov (United States)

    Yung, Winco K. C.; Sun, Bo; Meng, Zhengong; Huang, Junfeng; Jin, Yingdi; Choy, Hang Shan; Cai, Zhixiang; Li, Guijun; Ho, Cheuk Lam; Yang, Jinlong; Wong, Wai Yeung

    2016-12-01

    In recent years, 3D printing technologies have been extensively developed, enabling rapid prototyping from a conceptual design to an actual product. However, additive manufacturing of metals in the existing technologies is still cost-intensive and time-consuming. Herein a novel platform for low-cost additive manufacturing is introduced by simultaneously combining the laser-induced forward transfer (LIFT) method with photochemical reaction. Using acrylonitrile butadiene styrene (ABS) polymer as the sacrificial layer, sufficient ejection momentum can be generated in the LIFT method. A low-cost continuous wave (CW) laser diode at 405 nm was utilized and proved to be able to transfer the photochemically synthesized copper onto the target substrate. The wavelength-dependent photochemical behaviour in the LIFT method was verified and characterized by both theoretical and experimental studies compared to 1064 nm fiber laser. The conductivity of the synthesized copper patterns could be enhanced using post electroless plating while retaining the designed pattern shapes. Prototypes of electronic circuits were accordingly built and demonstrated for powering up LEDs. Apart from pristine PDMS materials with low surface energies, the proposed method can simultaneously perform laser-induced forward transfer and photochemical synthesis of metals, starting from their metal oxide forms, onto various target substrates such as polyimide, glass and thermoplastics.

  15. 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

  16. A peroxynitrite complex of copper: formation from a copper-nitrosyl complex, transformation to nitrite and exogenous phenol oxidative coupling or nitration.

    Science.gov (United States)

    Park, Ga Young; Deepalatha, Subramanian; Puiu, Simona C; Lee, Dong-Heon; Mondal, Biplab; Narducci Sarjeant, Amy A; del Rio, Diego; Pau, Monita Y M; Solomon, Edward I; Karlin, Kenneth D

    2009-11-01

    Reaction of nitrogen monoxide with a copper(I) complex possessing a tridentate alkylamine ligand gives a Cu(I)-(*NO) adduct, which when exposed to dioxygen generates a peroxynitrite (O=NOO(-))-Cu(II) species. This undergoes thermal transformation to produce a copper(II) nitrito (NO(2) (-)) complex and 0.5 mol equiv O(2). In the presence of a substituted phenol, the peroxynitrite complex effects oxidative coupling, whereas addition of chloride ion to dissociate the peroxynitrite moiety instead leads to phenol ortho nitration. Discussions include the structures (including electronic description) of the copper-nitrosyl and copper-peroxynitrite complexes and the formation of the latter, based on density functional theory calculations and accompanying spectroscopic data.

  17. Investigation of Superficial Resistance of Different Purity Copper at Boiling Nitrogen Temperature Depending on Treatment of Current-Conducting Layer

    International Nuclear Information System (INIS)

    Kutovoj, V.A.; Nikolaenko, A.A.; Stoev, P.I.

    2007-01-01

    Results of this scientific work show influence of annealing temperature and deformation degree of initial MOB copper and after electron beam refining on superficial resistance at temperature of boiling nitrogen. It is shown, that 30 % deformation and annealing in 873...923 K temperature range results in appreciable reduction of superficial resistance at the investigated samples of copper. The lowest values of superficial resistance after thermal and mechanical treatment were observed in the samples after electron beam refinement

  18. Two-step flash light sintering process for enhanced adhesion between copper complex ion/silane ink and a flexible substrate

    International Nuclear Information System (INIS)

    Jeon, Eun-Beom; Joo, Sung-Jun; Ahn, Heejoon; Kim, Hak-Sung

    2016-01-01

    A copper complex ion ink (including copper nanoparticles, a copper precursor and a silane coupling agent) was synthesized to enhance the adhesion between the copper pattern and a polyimide (PI) substrate. Oxygen plasma treatment was performed on the polyimide substrate to initiate a chemical reaction between the complex ion ink and the polyimide. Then, a two-step flash light sintering method (consisting of preheating and main sintering) was used to sinter the copper complex ion ink. The copper complex ion patterns were characterized as a function of the weight fraction of silane coupling agent using scanning electron microscopy (SEM), a four-point probe method and adhesion testing. In addition, a bending fatigue test was performed to evaluate the reliability of the conductive copper pattern under cyclic bending. The copper pattern fabricated with copper complex ion ink containing 3 wt% silane coupling agent exhibited the highest adhesion level (5B), the lowest resistivity (7.6 μΩ·cm) and a low resistance change (18%) after the bending fatigue test. The two-step sintering method used to enhance the adhesion between the copper complex ion ink and polyimide substrate was also studied using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). - Highlights: • The copper complex ion ink with copper nanoparticles and copper precursor was fabricated. • The copper complex ion ink was sintered by two-step flash light sintering method. • The sintered copper pattern exhibited the highest adhesion level (5B). • The resistivity of sintered copper pattern was 7.6 μΩ·cm.

  19. Properties of thermal air plasma with admixing of copper and carbon

    International Nuclear Information System (INIS)

    Fesenko, S; Veklich, A; Boretskij, V; Cressault, Y; Gleizes, A; Teulet, Ph

    2014-01-01

    This paper deals with investigations of air plasma with admixing of copper and carbon. Model plasma source unit with real breaking arc was used for the simulation of real discharges, which can be occurred during sliding of Cu-C composite electrodes on copper wire at electromotive vehicles. The complex technique of plasma property studies is developed. From one hand, the radial profiles of temperature and electron density in plasma of electric arc discharge in air between Cu-C composite and copper electrodes in air flow were measured by optical spectroscopy techniques. From another hand, the radial profiles of electric conductivity of plasma mixture were calculated by solution of energy balance equation. It was assumed that the thermal conductivity of air plasma is not depending on copper or carbon vapor admixtures. The electron density is obtained from electric conductivity profiles by calculation in assumption of local thermodynamic equilibrium in plasma. Computed in such way radial profiles of electron density in plasma of electric arc discharge in air between copper electrodes were compared with experimentally measured profiles. It is concluded that developed techniques of plasma diagnostics can be reasonably used in investigations of thermal plasma with copper and carbon vapors

  20. Computer simulated rate processes in copper vapor lasers

    Science.gov (United States)

    Harstad, K. C.

    1980-01-01

    A computer model for metal vapor lasers has been developed which places emphasis on the change of excited state populations of the lasant through inelastic collisions and radiative interaction. Also included are an energy equation for the pumping electrons and rate equations for laser photon densities. Presented are results of calculations for copper vapor with a neon buffer over a range of conditions. General agreement with experiments was obtained.

  1. Synthesis and structural studies of copper sulfide nanocrystals

    Directory of Open Access Journals (Sweden)

    Peter A. Ajibade

    Full Text Available We report the synthesis and structural studies of copper sulfide nanocrystals from copper(II dithiocarbamate single molecule precursors. The optical studies of the as-prepared copper sulfide nanoparticles were carried out using UV–Visible and photoluminescence spectroscopy. The absorption spectra show absorption band edges at 287 nm and exhibit considerable blue shift that could be ascribed to the quantum confinement effects as a result of the small crystallite sizes of the nanoparticles and the photoluminescence spectra show emission curves that are red shifted with respect to the absorption band edges. The structural studies were carried out using powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The XRD patterns revealed the formation of hexagonal structure of covellite CuS with estimated crystallite sizes of 17.3–18.6 nm. The TEM images showed particles with almost spherical or rod shapes with average crystallite sizes of 3–9.8 nm. SEM images showed morphology with ball-like microsphere on the surfaces and EDS spectra confirmed the presence of CuS nanoparticles. Keywords: CuS, Dithiocarbamate, Nanoparticles, Electron microscopy, AFM

  2. Superhydrophobic Copper Surfaces with Anticorrosion Properties Fabricated by Solventless CVD Methods.

    Science.gov (United States)

    Vilaró, Ignasi; Yagüe, Jose L; Borrós, Salvador

    2017-01-11

    Due to continuous miniaturization and increasing number of electrical components in electronics, copper interconnections have become critical for the design of 3D integrated circuits. However, corrosion attack on the copper metal can affect the electronic performance of the material. Superhydrophobic coatings are a commonly used strategy to prevent this undesired effect. In this work, a solventless two-steps process was developed to fabricate superhydrophobic copper surfaces using chemical vapor deposition (CVD) methods. The superhydrophobic state was achieved through the design of a hierarchical structure, combining micro-/nanoscale domains. In the first step, O 2 - and Ar-plasma etchings were performed on the copper substrate to generate microroughness. Afterward, a conformal copolymer, 1H,1H,2H,2H-perfluorodecyl acrylate-ethylene glycol diacrylate [p(PFDA-co-EGDA)], was deposited on top of the metal via initiated CVD (iCVD) to lower the surface energy of the surface. The copolymer topography exhibited a very characteristic and unique nanoworm-like structure. The combination of the nanofeatures of the polymer with the microroughness of the copper led to achievement of the superhydrophobic state. AFM, SEM, and XPS were used to characterize the evolution in topography and chemical composition during the CVD processes. The modified copper showed water contact angles as high as 163° and hysteresis as low as 1°. The coating withstood exposure to aggressive media for extended periods of time. Tafel analysis was used to compare the corrosion rates between bare and modified copper. Results indicated that iCVD-coated copper corrodes 3 orders of magnitude slower than untreated copper. The surface modification process yielded repeatable and robust superhydrophobic coatings with remarkable anticorrosion properties.

  3. Understanding the superconductivity in copper oxides

    CERN Document Server

    2019-01-01

    The aim of this book is to clarify the situation by adopting a very different approach from the above electronic/magnetic models, where explicitly local dynamical distortions are considered. These are distinctly different from conventional phonons which are a property of the infinite translational invariant symmetric lattice. The local dynamical distortions are shown to account for bulk properties and provide consistent and quantitative agreement with experimental data together with explicit predictions. Selected published experimental and theoretical papers are presented which support the above arguments, but have been ignored on purpose by the originators of the RVB/t-J bubble. To summarize the scope of this book, comprising nine chapters, it is shown, that the phenomenon of HTS in copper oxides is much better understood than publically claimed by RVB/t-J followers. Using the words of B. Laughlin, the presence of the antiferromagnetism in HTS masks the underlying physics where vibronic bipolarons with spin...

  4. Copper-rich invar by mechanical alloying

    Science.gov (United States)

    O'Donnell, K.; Qi, Qinian; Ilyushin, A. S.; Coey, J. M. D.

    1993-05-01

    An fcc alloy of composition Fe 64Cu 26Cr 7Ni 3 with a0 = 0.362 nm and an average crystalline size of 5 nm was produced by high-energy ball milling iron and copper powder in a stainless-steel container. The average number of electrons per atom is 8.7. The Curie temperature of the alloy is 410 K and the room-temperature magnetization is 48 JT -1 kg -1. The Mössbauer spectrum at 15 K shows a broad distribution of hyperfine field with an average of 15.6 T, which indicates coexistence of high and low moment states for iron. The alloy decomposes exothermically at 775 K to yield a mixture of bcc and fcc phases, but 50% of the iron remains in the fcc form with a low moment.

  5. Global transcriptional profiles of the copper responses in the cyanobacterium Synechocystis sp. PCC 6803.

    Directory of Open Access Journals (Sweden)

    Joaquin Giner-Lamia

    Full Text Available Copper is an essential element involved in fundamental processes like respiration and photosynthesis. However, it becomes toxic at high concentration, which has forced organisms to control its cellular concentration. We have recently described a copper resistance system in the cyanobacterium Synechocystis sp. PCC 6803, which is mediated by the two-component system, CopRS, a RND metal transport system, CopBAC and a protein of unknown function, CopM. Here, we report the transcriptional responses to copper additions at non-toxic (0.3 µM and toxic concentrations (3 µM in the wild type and in the copper sensitive copR mutant strain. While 0.3 µM copper slightly stimulated metabolism and promoted the exchange between cytochrome c6 and plastocyanin as soluble electron carriers, the addition of 3 µM copper catalyzed the formation of ROS, led to a general stress response and induced expression of Fe-S cluster biogenesis genes. According to this, a double mutant strain copRsufR, which expresses constitutively the sufBCDS operon, tolerated higher copper concentration than the copR mutant strain, suggesting that Fe-S clusters are direct targets of copper toxicity in Synechocystis. In addition we have also demonstrated that InrS, a nickel binding transcriptional repressor that belong to the CsoR family of transcriptional factor, was involved in heavy metal homeostasis, including copper, in Synechocystis. Finally, global gene expression analysis of the copR mutant strain suggested that CopRS only controls the expression of copMRS and copBAC operons in response to copper.

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  7. Leaching of Copper Ore by Thiobacillus Ferrooxidans.

    Science.gov (United States)

    Lennox, John; Biaha, Thomas

    1991-01-01

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

  8. Electrochemical behaviour of alkaline copper complexes

    Indian Academy of Sciences (India)

    cyanide- plating bath for copper has been developed using alkaline trisodium citrate and triethanolamine solutions5. The present investigation presents cyclic voltammetric studies on the electrochemical behaviour of alkaline copper complexes, ...

  9. 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.

  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. 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....

  12. Laser sintering of copper nanoparticles

    International Nuclear Information System (INIS)

    Zenou, Michael; Saar, Amir; Ermak, Oleg; Kotler, Zvi

    2014-01-01

    Copper nanoparticle (NP) inks serve as an attractive potential replacement to silver NP inks in functional printing applications. However their tendency to rapidly oxidize has so far limited their wider use. In this work we have studied the conditions for laser sintering of Cu-NP inks in ambient conditions while avoiding oxidation. We have determined the regime for stable, low-resistivity copper (< ×3 bulk resistivity value) generation in terms of laser irradiance and exposure duration and have indicated the limits on fast processing. The role of pre-drying conditions on sintering outcome has also been studied. A method, based on spectral reflectivity measurements, was used for non-contact monitoring of the sintering process evolution. It also indicates preferred spectral regions for sintering. Finally, we illustrated how selective laser sintering can generate high-quality, fine line (<5 µm wide) and dense copper circuits. (paper)

  13. The effects of impurities on the properties of OFP copper specified for the copper iron canister

    International Nuclear Information System (INIS)

    Bowyer, W.H.

    1999-09-01

    A brief literature study has addressed the effects of impurities on OF copper to which 50 ppm of phosphorus has been added. This copper is the candidate material for the corrosion resistant coating to be applied to the container under development by SKB for the disposal of high level nuclear waste. The levels of impurities expected in this grade of copper and the final use have controlled the focus of the work. It is concluded that the impurities of greatest importance in the context of the proposed application are sulphur, phosphorus, bismuth and lead. The addition of 50 ppm of phosphorus should ensure very low oxygen content in the copper such that, As, Ni, Mn, Cr, Fe, Sn, Zn, Si, Al, Sb and Cd present as impurities all remain in solution in the copper at all temperatures of interest. In this state they will exert no material effect on the fitness for purpose of the material. Sulphur is expected to be present in amounts exceeding the solubility limit such that it will occur as grain boundary films or particles. Such segregation can cause embrittlement and it will be more serious as grain size increases. There is no evidence to support the assertion that the phosphorus addition modifies the segregation behaviour of sulphur. There is evidence that sulphur will combine with V, Zr, or Ti, even when they are present at extremely low levels, but there is no indication of the likely effects of these combinations on the segregation behaviour or embrittling effects. There is clear evidence that when creep failure occurs by intergranular cracking, sulphur causes the creep strain to fracture to be reduced to less than 1%. The amount of sulphur required for this is very low (i.e. less than the amount permitted in the specification) and dependant on grain size. The transition from transgranular to intergranular failure in creep is influenced by temperature, stress, grain size, and composition. The addition of phosphorus increases the temperature at which the transition occurs

  14. The effects of impurities on the properties of OFP copper specified for the copper iron canister

    Energy Technology Data Exchange (ETDEWEB)

    Bowyer, W.H. [Meadow End Farm, Farnham (United Kingdom)

    1999-09-01

    A brief literature study has addressed the effects of impurities on OF copper to which 50 ppm of phosphorus has been added. This copper is the candidate material for the corrosion resistant coating to be applied to the container under development by SKB for the disposal of high level nuclear waste. The levels of impurities expected in this grade of copper and the final use have controlled the focus of the work. It is concluded that the impurities of greatest importance in the context of the proposed application are sulphur, phosphorus, bismuth and lead. The addition of 50 ppm of phosphorus should ensure very low oxygen content in the copper such that, As, Ni, Mn, Cr, Fe, Sn, Zn, Si, Al, Sb and Cd present as impurities all remain in solution in the copper at all temperatures of interest. In this state they will exert no material effect on the fitness for purpose of the material. Sulphur is expected to be present in amounts exceeding the solubility limit such that it will occur as grain boundary films or particles. Such segregation can cause embrittlement and it will be more serious as grain size increases. There is no evidence to support the assertion that the phosphorus addition modifies the segregation behaviour of sulphur. There is evidence that sulphur will combine with V, Zr, or Ti, even when they are present at extremely low levels, but there is no indication of the likely effects of these combinations on the segregation behaviour or embrittling effects. There is clear evidence that when creep failure occurs by intergranular cracking, sulphur causes the creep strain to fracture to be reduced to less than 1%. The amount of sulphur required for this is very low (i.e. less than the amount permitted in the specification) and dependant on grain size. The transition from transgranular to intergranular failure in creep is influenced by temperature, stress, grain size, and composition. The addition of phosphorus increases the temperature at which the transition occurs

  15. Refining processes in the copper casting technology

    OpenAIRE

    Rzadkosz, S.; Kranc, M.; Garbacz-Klempka, A.; Kozana, J.; Piękoś, M.

    2015-01-01

    The paper presents the analysis of technology of copper and alloyed copper destined for power engineering casts. The casts quality was assessed based on microstructure, chemical content analysis and strength properties tests. Characteristic deoxidising (Logas, Cup) and modifying (ODM2, Kupmod2) formulas were used for the copper where high electrical conductivity was required. Chosen examples of alloyed copper with varied Cr and Zr content were studied, and the optimal heat treatment parameter...

  16. Picosecond laser induced periodic surface structure on copper thin films

    International Nuclear Information System (INIS)

    Huynh, Thi Trang Dai; Petit, Agnès; Semmar, Nadjib

    2014-01-01

    LIPSS (Laser Induced Periodic Surface Structure) formation on copper thin films induced by a picosecond laser beam (Nd:YAG laser at 266 nm, 42 ps and 10 Hz) was studied experimentally. Copper thin films were deposited on glass and silicon substrates by magnetron sputtering. The surface modifications of irradiated zones were analyzed by scanning electron microscopy. Two distinct types of LIPSS were identified with respect to the laser fluence (F), number of laser shots (N) and substrate material. Namely, with a number of laser shots (1000 2 2 ), Low Spatial Frequency LIPSS (LSFL with a spatial period of Λ ∼ 260 nm and an orientation perpendicular to polarization) and High Spatial Frequency LIPSS (HSFL with a spatial period of Λ ∼ 130 nm and an orientation parallel to the polarization) were observed. The regime of regular spikes formation was determined for N ≥ 1000. Moreover, the 2D-map of the relationship among LIPSS formation, laser fluence and number of laser shots on copper thin film with two different substrates was established. A physics interpretation of regular spikes and LIPSS formation on copper thin film induced by ps laser with overlapping multi-shots is proposed based on experimental data and the theory of Plateau-Rayleigh instability.

  17. Evolution of patinas on copper exposed in a suburban area

    International Nuclear Information System (INIS)

    Watanabe, Masamitsu; Toyoda, Etsuko; Handa, Takao; Ichino, Toshihiro; Kuwaki, Nobuo; Higashi, Yasuhiro; Tanaka, Tohru

    2007-01-01

    Copper plates were exposed under sheltered outdoor conditions for up to one year, starting in September 2001 in Musashino City, Tokyo, a suburban area. Following various periods of exposure, the patinas on the plates were characterized to investigate their evolution by using X-ray fluorescence analysis, X-ray diffraction, field emission scanning electron microscopy, and glow discharge optical emission spectroscopy. The difference in the roles of sulfur and chlorine in the early stages of copper patination were identified by analyzing the depth profiles of these two elements. Sulfur was found on top of the patina as cupric sulfates such as posnjakite (Cu 4 SO 4 (OH) 6 . H 2 O) or brochantite (Cu 4 SO 4 (OH) 6 ). Brochantite appeared only after 12 months of exposure. In contrast, chlorine was found on the surface after only one month of exposure. It gradually penetrated the patina as the exposure period lengthened, forming copper chloride complexes. Chloride ions accumulated at the patina/copper interface, forming nantokite (CuCl), which promoted corrosion

  18. Laser additive manufacturing bulk graphene-copper nanocomposites.

    Science.gov (United States)

    Hu, Zengrong; Chen, Feng; Lin, Dong; Nian, Qiong; Parandoush, Pedram; Zhu, Xing; Shao, Zhuqiang; Cheng, Gary J

    2017-11-03

    The exceptional mechanical properties of graphene make it an ideal nanofiller for reinforcing metal matrix composites (MMCs). In this work, graphene-copper (Gr-Cu) nanocomposites have been fabricated by a laser additive manufacturing process. Transmission electron microscopy (TEM), x-ray diffraction (XRD) and Raman spectroscopy were utilized to characterize the fabricated nanocomposites. The XRD, Raman spectroscopy, energy dispersive spectroscopy and TEM results demonstrated the feasibility of laser additive manufacturing of Gr-Cu nanocomposites. The microstructures were characterized by high resolution TEM and the results further revealed the interface between the copper matrix and graphene. With the addition of graphene, the mechanical properties of the composites were enhanced significantly. Nanoindentation tests showed that the average modulus value and hardness of the composites were 118.9 GPa and 3 GPa respectively; 17.6% and 50% increases were achieved compared with pure copper, respectively. This work demonstrates a new way to manufacture graphene copper nanocomposites with ultra-strong mechanical properties and provides alternatives for applications in electrical and thermal conductors.

  19. Electrical conduction in composites containing copper core–copper ...

    Indian Academy of Sciences (India)

    Unknown

    of Mott's small polaron hopping conduction model. ... sample exhibited a metallic conduction confirming the formation of a percolative chain of ..... value of εp. Also the oxide layer formation on the initially unoxidized copper particles will increase the resistivity level of the nanocomposite. This is borne out by results shown in ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-03-15

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

  1. Structure transitions between copper-sulphate and copper-chloride ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Structure transitions between copper UPD adlayers on Au(111)–(1 × 1) in sulfuric acid and chloride containing electrolyte were investigated by in situ scanning tunnelling microscopy. We demon- strate that co-adsorbed sulphate ions in the (√3 × √3)R30° UPD adlayer are replaced by chloride ions and,.

  2. Biogenic copper oxide nanoparticles synthesis using Tabernaemontana divaricate leaf extract and its antibacterial activity against urinary tract pathogen.

    Science.gov (United States)

    Sivaraj, Rajeshwari; Rahman, Pattanathu K S M; Rajiv, P; Salam, Hasna Abdul; Venckatesh, R

    2014-12-10

    This investigation explains the biosynthesis and characterization of copper oxide nanoparticles from an Indian medicinal plant by an eco-friendly method. The main objective of this study is to synthesize copper oxide nanoparticles from Tabernaemontana divaricate leaves through a green chemistry approach. Highly stable, spherical copper oxide nanoparticles were synthesized by using 50% concentration of Tabernaemontana leaf extract. Formation of copper oxide nanoparticles have been characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM) analysis. All the analyses revealed that copper oxide nanoparticles were 48±4nm in size. Functional groups and chemical composition of copper oxide were also confirmed. Antimicrobial activity of biogenic copper oxide nanoparticles were investigated and maximum zone of inhibition was found in 50μg/ml copper oxide nanoparticles against urinary tract pathogen (Escherichia coli). Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Copper(I) halide complexes with 1,3-propanebis(diphenylphosphine) and heterocyclic thione ligands: crystal and electronic structures (DFT) of [CuCl(pymtH)(dppp)], [CuBr(pymtH)(dppp)], and [Cu(mu-I)(dppp)](2).

    Science.gov (United States)

    Aslanidis, Paraskevas; Cox, Philip J; Divanidis, Savvas; Tsipis, Athanassios C

    2002-12-16

    Reaction of copper(I) chloride or bromide with equimolar amounts of the diphos ligand 1,3-propanebis(diphenylphosphine) and a heterocyclic thione (L) in acetonitrile/methanol solvent afforded mononuclear complexes of the type [CuX(dppp)(L)] with the diphosphine ligand acting as a chelating ligand. In contrast, copper(I) iodide under the same conditions gave the dimeric complex [Cu(mu-I)(dppp)](2), which contains doubly bridging iodo ligands. The structures of three complexes, namely, [CuCl(pymtH)(dppp)], [CuCl(pymtH)(dppp)], and [Cu(mu-I)(dppp)](2), have been established by single-crystal X-ray diffraction. Density functional calculations at the B3LYP level of theory provided a satisfactory description of the structural, bonding, electronic, and related properties of the [CuX(PH(3))(2)] and [CuX(1,3-pdp)] (1,3-pdp = 1,3-propane-di-phosphine) complexes and their dimers along with their associations with the pyrimidine-2-thione (pymtH) ligand. The interaction of the pymtH ligand with the Cu(I) metal center in these complexes corresponds to loose associations, the computed interaction energies predicted to be about 20 kcal/mol for all complexes in the series. The bonding mechanism of the thione ligand with the Cu(I) metal centers involves both a sigma-dative and pi-back-bonding components. The coordination of the pymtH ligand is further stabilized by X...H-N bond formation being more pronounced in the chloro than in the iodo derivatives. The Cu-X bond was also found to be a composite bond involving sigma- and pi-dative bonding components. Most important is the presence of pi-type MOs delocalized over the entire four-membered Cu(mu-X)(2)Cu ring, which supports a ring current and could probably account for the nearly equivalent Cu-X bonds in the rhombus. Moreover, all [Cu(mu-X)(PH(3))(2)](2) dimers exhibit a sigma-type MO corresponding to weak Cu.Cu interactions supporting through-ring intermetallic interactions, which seems to be responsible for the stabilization of

  4. 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.

  5. Effect of soluble copper released from copper oxide nanoparticles solubilisation on growth and photosynthetic processes of Lemna gibba L.

    Science.gov (United States)

    Perreault, François; Samadani, Mahshid; Dewez, David

    2014-06-01

    Copper oxide nanoparticles (CuO NPs) are used as a biocide in paints, textiles and plastics. Their application may lead to the contamination of aquatic ecosystems, where potential environmental effects remain to be determined. Toxic effects may be related to interactions of NPs with cellular systems or to particles' solubilisation releasing metal ions. In this report, we evaluated CuO NPs and soluble copper effects on photosynthesis of the aquatic macrophyte Lemna gibba L to determine the role of particle solubility in NPs toxicity. When L. gibba plants were exposed 48 h to CuO NPs or soluble copper, inhibition of photosynthetic activity was found, indicated by the inactivation of Photosystem II reaction centers, a decrease in electron transport and an increase of thermal energy dissipation. Toxicity of CuO NPs was mainly driven by copper ions released from particles. However, the bioaccumulation of CuO NPs in plant was shown, indicating the need to evaluate organisms of higher trophic level.

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

    Energy Technology Data Exchange (ETDEWEB)

    Shelepova, Ekaterina V. [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk, 630090 (Russian Federation); National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk, 634050 (Russian Federation); Vedyagin, Aleksey A., E-mail: vedyagin@catalysis.ru [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk, 630090 (Russian Federation); National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk, 634050 (Russian Federation); Ilina, Ludmila Yu.; Nizovskii, Alexander I. [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk, 630090 (Russian Federation); Tsyrulnikov, Pavel G. [Institute of Hydrocarbon Processing SB RAS, Neftezavodskaya st., 54, Omsk, 644040 (Russian Federation)

    2017-07-01

    Highlights: • Carbon-supported copper catalyst was studied in dehydrogenation of methanol. • Reduction temperature affected size of Cu particles and Cu{sup 0}/Cu{sup 2+} ratio. • Reduction at 400 °C was required to obtain high methyl formate yield. - Abstract: 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.

  7. Corrosion Resistance and Durability of Superhydrophobic Copper Surface in Corrosive NaCl Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Chun-Wei Yao

    2018-02-01

    Full Text Available Artificial superhydrophobic copper surfaces play an important role in modern applications such as self-cleaning and dropwise condensation; however, corrosion resistance and durability often present as major concerns in such applications. In this study, the anti-corrosion properties and mechanical durability of superhydrophobic copper surface have been investigated. The superhydrophobic copper surfaces were achieved with wet chemical etching and an immersion method to reduce the complexity of the fabrication process. The surface structures and materials were characterized using scanning electron microscope (SEM, energy dispersive X-ray spectroscopy (EDX, and Fourier transform infrared spectrometer (FTIR. The corrosion resistance and mechanical properties of the superhydrophobic copper surface were characterized after immersing surfaces in a 3.5 wt % NaCl solution. The chemical stability of the superhydrophobic copper surface in the NaCl solution for a short period of time was also evaluated. An abrasion test and an ultrasound oscillation were conducted to confirm that the copper surface contained durable superhydrophobic properties. In addition, an atomic force microscope was employed to study the surface mechanical property in the corrosion conditions. The present study shows that the resulting superhydrophobic copper surface exhibit enhanced corrosion resistance and durability.

  8. Effect of electrolysis parameters on the morphologies of copper powder obtained at high current densities

    Directory of Open Access Journals (Sweden)

    Orhan Gökhan

    2012-01-01

    Full Text Available The effects of copper ion concentrations and electrolyte temperature on the morphologies and on the apparent densities of electrolytic copper powders at high current densities under galvanostatic regime were examined. These parameters were evaluated by the current efficiency of hydrogen evolution. In addition, scanning electron microscopy was used for analyzing the morphology of the copper powders. It was found that the morphology was dependent over the copper ion concentration and electrolyte temperature under same current density (CD conditions. At 150 mA cm-2 and the potential of 1000±20 mV (vs. SCE, porous and disperse copper powders were obtained at low concentrations of Cu ions (0.120 M Cu2+ in 0.50 M H2SO4. Under this condition, high rate of hydrogen evolution reaction took place parallel to copper electrodeposition. The morphology was changed from porous, disperse and cauliflower-like to coral-like, shrub-like and stalk-stock like morphology with the increasing of Cu ion concentrations towards 0.120 M, 0.155 M, 0.315 M, 0.475 M and 0.630 M Cu2+ in 0.5 M H2SO4 respectively at the same CD. Similarly, as the temperature was increased, powder morphology and apparent density were observed to be changed. The apparent density values of copper powders were found to be suitable for many of the powder metallurgy applications.

  9. Controlled release of copper from an intrauterine device using a biodegradable polymer.

    Science.gov (United States)

    Ramakrishnan, Reshmi; B, Bharaniraja; Aprem, Abi Santhosh

    2015-12-01

    The adverse effects of copper intrauterine devices (IUDs) such as abnormal bleeding, pain and cramps may be due in part to the burst release of copper ions during the first few months of usage. This study focuses on controlling the initial burst release of copper ions. This study evaluated in vitro release rates of copper for a period of 1 year from standard CuT380 IUDs (n=6) and from CuT380 IUDs coated with poly(dl-lactide-co-glycolide) (PLGA) films (n=6). This study characterized the coated device for its morphological changes during degradation of film by scanning electron microscopy (SEM). CuT380 IUDs coated with PLGA film with a thickness of 0.10±0.02 mm showed a reduced initial copper release (40-80 mcg/day) compared with uncoated CuT380 IUDs (150-200 mcg/day). Statistically significant (p<.05) results were obtained at different time intervals during the overall study period of 1 year. SEM images showed degradation of coating. Coating a CuT380 IUD with biodegradable polymer reduced the initial copper release without affecting release at 1 year. Clinical trials are required to determine whether this could reduce side effects such as bleeding and pain associated with copper containing IUDs. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Green Fabrication of Copper Nanoparticles Dispersed in Walnut Oil Using Laser Ablation Technique

    Directory of Open Access Journals (Sweden)

    Amir Reza Sadrolhosseini

    2016-01-01

    Full Text Available Synthesis of copper nanoparticles was achieved by laser irradiation of copper plate in walnut oil. The copper plate was irradiated using Nd:YAG pulse laser at different ablation time from 5 to 50 minutes, and the prepared samples were characterized using analytical methods to find the optical absorption, morphology, particle size, and capping of copper nanoparticles with walnut oil. Consequently, the absorption peak appeared at about 615, 606, 588, 576, and 561 nm; and the nanoparticles formed in spherical shape in walnut oil. The particle size varied from 25 to 4.01 nm, and the tail of the carbonyl band capped the copper nanoparticles through the electron transfer from the carboxylic group to copper nanoparticles. The refractive indices of the nanofluid were measured using a surface plasmon resonance technique and changed from 1.4691 + 0.008i to 1.4682 + 0.043i as the volume fraction increased from 0.0257 × 10−5 to 1.26 × 10−5. Consequently, the laser ablation method is environmentally sensitive (i.e., green and thus is suitable for the fabrication of copper nanoparticles in walnut oil without any agent.

  11. Excimer laser produced plasmas in copper wire targets and water droplets

    Science.gov (United States)

    Song, Kyo-Dong; Alexander, D. R.

    1994-01-01

    Elastically scattered incident radiation (ESIR) from a copper wire target illuminated by a KrF laser pulse at lambda = 248 nm shows a dinstinct two-peak structure which is dependent on the incident energy. The time required to reach the critical electron density (n(sub c) approximately = 1.8 x 10(exp 22) electrons/cu cm) is estimated at 11 ns based on experimental results. Detailed ESIR characteristics for water have been reported previously by the authors. Initiation of the broadband emission for copper plasma begins at 6.5 +/- 1.45 ns after the arrival of the laser pulse. However, the broadband emission occurs at 11 +/- 0.36 ns for water. For a diatomic substance such as water, the electron energy rapidly dissipates due to dissociation of water molecules, which is absent in a monatomic species such as copper. When the energy falls below the excitation energy of the lowest electron state for water, it becomes a subexcitation electron. Lifetimes of the subexcited electrons to the vibrational states are estimated to be of the order of 10(exp -9) s. In addition, the ionization potential of copper (440-530 nm) is approximately 6 eV, which is about two times smaller than the 13 eV ionization potential reported for water. The higher ionization potential contributes to the longer observed delay time for plasma formation in water. After initiation, a longer time is required for copper plasma to reach its peak value. This time delay in reaching the maximum intensity is attributed to the energy loss during the interband transition in copper.

  12. on THICKNESS OF COPPER (|) OXIDE

    African Journals Online (AJOL)

    2006-12-20

    Dec 20, 2006 ... semiconductor devices. The oxide is. Observed to be an attractive starting material for the production of solar cells for low cost terrestrial conversion of solar energy to electricity. Copper (I) oxide is one Of the earliest known photovoltaic materials and the first in which the photovOltaic effect was successfully ...

  13. A Study of Protection of Copper Alloys

    International Nuclear Information System (INIS)

    Kim, E. A.; Kim, S. H.; Kim, C. R.

    1974-01-01

    Volatile treatment of high capacity boiler water with hydrazine and ammonia is studied. Ammonia comes from the decomposition of excess hydrazine injected to treat dissolved oxygen. Ammonia is also injected for the control of pH. To find an effect of such ammonia on the copper alloy, the relations between pH and iron, and ammonia and copper are studied. Since the dependence of corrosion of iron on pH differs from that of copper, a range of pH was selected experimentally to minimize the corrosion rates of both copper and iron. Corrosion rates of various copper alloys are also compared

  14. Chronic copper toxicity in a dairy herd

    OpenAIRE

    Perrin, David J.; Schiefer, H. Bruno; Blakley, Barry R.

    1990-01-01

    The addition of excessive copper to a commercially prepared dairy ration caused chronic copper toxicity in a dairy herd. A formulation error by a feed company resulted in copper levels of 800 to 1,000 mg/kg in the “as fed concentrate,” amounting to about 400-500 mg copper/kg of the whole ration. Five animals died with typical signs of acute copper toxicity, including intravascular hemolysis and methemoglobinemia. A further 39 cows died on the farm from a combination of debilitation and second...

  15. Fabricated super-hydrophobic film with potentiostatic electrolysis method on copper for corrosion protection

    International Nuclear Information System (INIS)

    Wang Peng; Qiu Ri; Zhang Dun; Lin Zhifeng; Hou Baorong

    2010-01-01

    A novel one-step potentiostatic electrolysis method was proposed to fabricate super-hydrophobic film on copper surface. The resulted film was characterized by contact angle tests, Fourier transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS), Field emission scanning electron microscopy (FE-SEM) and electrochemical measurements. It could be inferred that the super-hydrophobic property resulted from the flower-like structure of copper tetradecanoate film. In the presence of super-hydrophobic film, the anodic and cathodic polarization current densities are reduced for more than five and four orders of magnitude, respectively. The air trapped in the film is the essential contributor of the anticorrosion property of film for its insulation, the copper tetradecanoate film itself acts as a 'frame' to trap air as well as a coating with inhibition effect. The super-hydrophobic film presents excellent inhibition effect to the copper corrosion and stability in water containing Cl - .

  16. Synthesis of Copper Nanoparticles Biologically by Conocarpus erectus L. Aqueous Leaves Extract

    Directory of Open Access Journals (Sweden)

    Rihab Edan Kadhim

    2018-03-01

    Full Text Available Biologically, the nanoparticles of copper synthesized by aqueous leaves extract of Cono- carpus erectus L. The copper nanoparticles appear rapidly with change in color when the leaf extract mixed with CuSO4 (0.1mM. The copper nanoparticles were character- ized by UV Visible Absorption Spectrometer (UV-S, X-Ray Diffraction (XRD, Fourier Transform infrared (FTIR, and Scanning Electron Microscopes (SEM. By using UV-S, the wave length was around 400 nm, while the size of copper nanoparticles was around 39 nm characterized by XRD and SEM. The technique of FTIR showed the presence of active sites for alcoholic, phenolic, amines and other compounds.

  17. Electroless copper plating on 3-mercaptopropyltriethoxysilane modified PET fabric challenged by ultrasonic washing

    International Nuclear Information System (INIS)

    Lu Yinxiang

    2009-01-01

    Electroless deposition of Cu on poly(ethylene terephthalate) (PET) fabric modified with 3-mercaptopropyltriethoxysilane was investigated. Morphology, composition, structure, thermal decomposing behavior of copper coating PET fabric after ultrasonic washing in water for 1 h were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), Raman spectrometer, X-ray diffraction (XRD), and thermogravimetric analysis (TG), respectively. Copper plating on modified fabric has good adherence stability and high electric conductivity before and after ultrasonic washing, while copper coating fabric without modification is easily destroyed during the washing process, which leads to the textile changing from conductor to dielectric. As the copper weight on the treated fabric is 28 g/m 2 , the shielding effectiveness (SE) is more than 54 dB at frequency ranging from 0.01 MHz to 18 GHz.

  18. Effect of Sulfide Concentration on Copper Corrosion in Anoxic Chloride-Containing Solutions

    Science.gov (United States)

    Kong, Decheng; Dong, Chaofang; Xu, Aoni; Man, Cheng; He, Chang; Li, Xiaogang

    2017-04-01

    The structure and property of passive film on copper are strongly dependent on the sulfide concentration; based on this, a series of electrochemical methods were applied to investigate the effect of sulfide concentration on copper corrosion in anaerobic chloride-containing solutions. The cyclic voltammetry and x-ray photoelectron spectroscopy analysis demonstrated that the corrosion products formed on copper in anaerobic sulfide solutions comprise Cu2S and CuS. And the corrosion resistance of copper decreased with increasing sulfide concentration and faster sulfide addition, owing to the various structures of the passive films observed by the atomic force microscope and scanning electron microscope. A p-type semiconductor character was obtained under all experimental conditions, and the defect concentration, which had a magnitude of 1022-1023 cm-3, increased with increasing sulfide concentration, resulting in a higher rate of both film growth and dissolution.

  19. Large single crystals of graphene on melted copper using chemical vapor deposition.

    Science.gov (United States)

    Wu, Yimin A; Fan, Ye; Speller, Susannah; Creeth, Graham L; Sadowski, Jerzy T; He, Kuang; Robertson, Alex W; Allen, Christopher S; Warner, Jamie H

    2012-06-26

    A simple method is presented for synthesizing large single crystal graphene domains on melted copper using atmospheric pressure chemical vapor deposition (CVD). This is achieved by performing the reaction above the melting point of copper (1090 °C) and using a molybdenum or tungsten support to prevent balling of the copper from dewetting. By controlling the amount of hydrogen during growth, individual single crystal domains of monolayer graphene greater than 200 μm are produced within a continuous film. Stopping growth before a complete film is formed reveals individual hexagonal domains of graphene that are epitaxially aligned in their orientation. Angular resolved photoemission spectroscopy is used to show that the graphene grown on copper exhibits a linear dispersion relationship and no sign of doping. HRTEM and electron diffraction reveal a uniform high quality crystalline atomic structure of monolayer graphene.

  20. A facile biosynthesis of copper nanoparticles: A micro-structural and antibacterial activity investigation

    Directory of Open Access Journals (Sweden)

    Y.T. Prabhu

    2017-02-01

    Full Text Available Nanostructured copper particles are synthesized by Garcinia mangostana leaf extract as reducing agent with copper nitrate. X-ray diffraction study confirms the formation of nanocrystalline cubic phase of copper nanoparticles. The micro-structural properties such as grain size, strain, dislocation density and particle size are examined. The lattice constant is calculated using Nelson–Riley function. Physical parameters like lattice constants, stress, strain, dislocation density and size are calculated. Differential thermal analysis (DTA and thermo gravimetric (TGA have confirmed that nanoparticles have phase purity and weight loss percentage is 3.328%. The particle size calculated from XRD is 26.51 nm which is in good agreement with the results of W–H plot, SSP methods and particle analyser. The morphology of prepared copper nanoparticles is characterized by scanning electron microscope (SEM and TEM. These biologically synthesized nanoparticles are highly antibacterial against Escherichia coli and Staphylococcus aureus.

  1. Synthesis and characterization of copper nanoparticles by using the exploding wire method

    International Nuclear Information System (INIS)

    Das, Rashmita; Das, Basanta Kumar; Shyam, Anurag

    2012-01-01

    During the past few years, the synthesis of copper nanoparticles has attracted much attention because of their huge potential for replacing the expensive nano silver inks utilized in conductive printing. This opens a new possibility in printed electronics. Copper-based inkjet inks can be used to form various devices such as solar cells, RF identification tags and electroluminescence devices. This paper describes controlled synthesis of pure copper nanoparticles, mainly by using the exploding wire method. A wire of 0.26 mm in diameter was exploded in a nitrogen environment. The sample was characterized by using X-ray diffraction (XRD) and atomic force microscopy (AFM). XRD revealed the presence of pure copper and AFM revealed the presence of nanoparticles with an average size of 55 nm.

  2. Insights into the oxidative degradation of cellulose by a copper metalloenzyme that exploits biomass components.

    Science.gov (United States)

    Quinlan, R Jason; Sweeney, Matt D; Lo Leggio, Leila; Otten, Harm; Poulsen, Jens-Christian N; Johansen, Katja Salomon; Krogh, Kristian B R M; Jørgensen, Christian Isak; Tovborg, Morten; Anthonsen, Annika; Tryfona, Theodora; Walter, Clive P; Dupree, Paul; Xu, Feng; Davies, Gideon J; Walton, Paul H

    2011-09-13

    The enzymatic degradation of recalcitrant plant biomass is one of the key industrial challenges of the 21st century. Accordingly, there is a continuing drive to discover new routes to promote polysaccharide degradation. Perhaps the most promising approach involves the application of "cellulase-enhancing factors," such as those from the glycoside hydrolase (CAZy) GH61 family. Here we show that GH61 enzymes are a unique family of copper-dependent oxidases. We demonstrate that copper is needed for GH61 maximal activity and that the formation of cellodextrin and oxidized cellodextrin products by GH61 is enhanced in the presence of small molecule redox-active cofactors such as ascorbate and gallate. By using electron paramagnetic resonance spectroscopy and single-crystal X-ray diffraction, the active site of GH61 is revealed to contain a type II copper and, uniquely, a methylated histidine in the copper's coordination sphere, thus providing an innovative paradigm in bioinorganic enzymatic catalysis.

  3. Formulation and development of a methodology for selecting desulfurization processes, applicable to diluted sulfurous emissions from copper. Preparation of the engineering for a draft project using electron beam process, selected with this methodology

    International Nuclear Information System (INIS)

    Aros M, Patricia.

    1997-01-01

    A comparative study of clean desulfurization technologies was prepared. Sulfur abatement processes from S O 2 gas streams were analyzed in 21 processes grouped into 8 different types. Since there are a large number of potentially applicable processes, this thesis presents a process selection methodology based on a technical/economic analysis series, which produces a ranking by scores. Visual Basic 3.0 software was used to develop the program, which can be installed in any computer and uses Windows 95. Based on these results in Chilean Nuclear Energy Commission decided to present a draft project for electron beam technology. The full design and calculation for the humidifying and cooling tower was prepared together with the design of the remaining equipment for size, in order to estimate probable costs. The pre-feasibility evaluation determined that the process would generate profits, when the selling price of ammonium sulfate - which is a byproduct of the process that is used as fertilizer - is above US$ 110/ton. The process cost is heavily influenced by the capital cost of storage facilities, since a long term supply for ammonia reagent is needed. This product is imported in Chile and it is currently an expensive reagent. (author). 33 app., 7 tabs

  4. Aqueous synthesis of PEGylated copper sulfide nanoparticles for photoacoustic imaging of tumors

    Science.gov (United States)

    Ding, Ke; Zeng, Jianfeng; Jing, Lihong; Qiao, Ruirui; Liu, Chunyan; Jiao, Mingxia; Li, Zhen; Gao, Mingyuan

    2015-06-01

    vivo. Although the contrast enhancement effect of the copper sulfide NPs is proportional to particle size, the in vivo studies revealed that copper sulfide NPs smaller than 5 nm presented higher tumor imaging performance, especially at the tumor boundary site, which was further discussed in combination with the pharmacokinetic behaviors of differently sized particles. Electronic supplementary information (ESI) available: XRD results, theoretical hydrodynamic size, temporal evolution of TGA-capped copper sulfide NPs, concentration-dependent growth-inhibition of HeLa cells. See DOI: 10.1039/c5nr02180d

  5. Functionally specified protein signatures distinctive for each of the different blue copper proteins

    Directory of Open Access Journals (Sweden)

    Anishetty Sharmila

    2004-09-01

    Full Text Available Abstract Background Proteins having similar functions from different sources can be identified by the occurrence in their sequences, a conserved cluster of amino acids referred to as pattern, motif, signature or fingerprint. The wide usage of protein sequence analysis in par with the growth of databases signifies the importance of using patterns or signatures to retrieve out related sequences. Blue copper proteins are found in the electron transport chain of prokaryotes and eukaryotes. The signatures already existing in the databases like the type 1 copper blue, multiple copper oxidase, cyt b/b6, photosystem 1 psaA&B, psaG&K, and reiske iron sulphur protein are not specified signatures for blue copper proteins as the name itself suggests. Most profile and motif databases strive to classify protein sequences into a broad spectrum of protein families. This work describes the signatures designed based on the copper metal binding motifs in blue copper proteins. The common feature in all blue copper proteins is a trigonal planar arrangement of two nitrogen ligands [each from histidine] and one sulphur containing thiolate ligand [from cysteine], with strong interactions between the copper center and these ligands. Results Sequences that share such conserved motifs are crucial to the structure or function of the protein and this could provide a signature of family membership. The blue copper proteins chosen for the study were plantacyanin, plastocyanin, cucumber basic protein, stellacyanin, dicyanin, umecyanin, uclacyanin, cusacyanin, rusticyanin, sulfocyanin, halocyanin, azurin, pseudoazurin, amicyanin and nitrite reductase which were identified in both eukaryotes and prokaryotes. ClustalW analysis of the protein sequences of each of the blue copper proteins was the basis for designing protein signatures or peptides. The protein signatures and peptides identified in this study were designed involving the active site region involving the amino acids

  6. Controlling Copper Electrochemical Deposition (ECD)

    Science.gov (United States)

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

    2003-09-01

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

  7. Radiation induced segregation and point defects in binary copper alloys

    International Nuclear Information System (INIS)

    Monteiro, W.A.

    1984-01-01

    Considerable progress, both theoretical and experimental, has been made in establishing and understanding the influence of factors such as temperature, time, displacement rate dependence and the effect of initial solute misfit on radiation induced solute diffusion and segregation. During irradiation, the composition of the alloy changes locally, due to defect flux driven non-equilibrium segregation near sinks such as voids, external surfaces and grain boundaries. This change in composition could influence properties and phenomena such as ductility, corrosion resistance, stress corrosion cracking, sputtering and blistering of materials used in thermo-nuclear reactors. In this work, the effect of 1 MeV electron irradiation on the initiation and development of segregation and defect diffusion in binary copper alloys has been studied in situ, with the aid of a high voltage electron microscope. The binary copper alloys had Be, Pt and Sn as alloying elements which had atomic radii less than, similar and greater than that of copper, respectively. It has been observed that in a wide irradiation temperature range, stabilization and growth of dislocation loops took place in Cu-Sn and Cu-Pt alloys. Whereas in the Cu-Be alloy, radiation induced precipitates formed and transformed to the stable γ phase. (Author) [pt

  8. Transferring the entatic-state principle to copper photochemistry

    Science.gov (United States)

    Dicke, B.; Hoffmann, A.; Stanek, J.; Rampp, M. S.; Grimm-Lebsanft, B.; Biebl, F.; Rukser, D.; Maerz, B.; Göries, D.; Naumova, M.; Biednov, M.; Neuber, G.; Wetzel, A.; Hofmann, S. M.; Roedig, P.; Meents, A.; Bielecki, J.; Andreasson, J.; Beyerlein, K. R.; Chapman, H. N.; Bressler, C.; Zinth, W.; Rübhausen, M.; Herres-Pawlis, S.

    2018-03-01

    The entatic state denotes a distorted coordination geometry of a complex from its typical arrangement that generates an improvement to its function. The entatic-state principle has been observed to apply to copper electron-transfer proteins and it results in a lowering of the reorganization energy of the electron-transfer process. It is thus crucial for a multitude of biochemical processes, but its importance to photoactive complexes is unexplored. Here we study a copper complex—with a specifically designed constraining ligand geometry—that exhibits metal-to-ligand charge-transfer state lifetimes that are very short. The guanidine-quinoline ligand used here acts on the bis(chelated) copper(I) centre, allowing only small structural changes after photoexcitation that result in very fast structural dynamics. The data were collected using a multimethod approach that featured time-resolved ultraviolet-visible, infrared and X-ray absorption and optical emission spectroscopy. Through supporting density functional calculations, we deliver a detailed picture of the structural dynamics in the picosecond-to-nanosecond time range.

  9. Serum copper and ceruloplasmin levels and urinary copper excretion in thermal injury.

    Science.gov (United States)

    Boosalis, M G; McCall, J T; Solem, L D; Ahrenholz, D H; McClain, C J

    1986-12-01

    Conflicting reports regarding copper status in thermal injury patients have been published. We determined serial serum-copper and serum-ceruloplasmin levels and 24-h urinary excretion of copper in 23 patients with second- and third-degree thermal burns. Throughout hospitalization, mean serum-copper concentration was significantly depressed; lowest levels were found in patients with greater than 40% total body surface area burns. Serum ceruloplasmin was also depressed, an unexpected finding because this protein is a positive acute-phase reactant poststress. Mean urinary excretion of copper was elevated, reaching 2.5 times the upper limit of normal 2 wk postburn. Depressed serum-copper levels paralleled the serum-ceruloplasmin levels rather than the increased urinary-copper losses. Further studies are required to determine the mechanism(s) of this altered copper metabolism and whether physiological or biochemical evidence of copper deficiency accompanies the observed hypocupremia.

  10. Variations of serum copper values in pregnancy

    Directory of Open Access Journals (Sweden)

    Vukelić Jelka

    2012-01-01

    Full Text Available 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 pathological pregnancies and if this is of some importance. Methods. A total of 2170 plasma samples for copper analyses were made in the following groups: healthy non-pregnant women; healthy pregnant women from the 5th-40th gestational week, during the first delivery stage and during the first three postpartum weeks, in pregnant women with habitual abortion, imminent abortion, abortion in progress, missed abortion (9th-24th weeks, missed labour and premature rupture of membranes (29th-40th weeks. Levels of serum copper were determined by colorimetric technique of bathocuproin with disulphate as a chromogen. Results. Serum copper values in non-pregnant women range from 11.6-25.8 μmol/L. In healthy pregnant women, there is a constant trend of the increase of serum copper. The mean serum copper values revealed three significant peaks at the 22nd, 27th and 35th gestational week. Serum copper values in the patients with some pathological pregnancies in relation to the serum copper values of the healthy pregnant women were significantly lower. Conclusion. Serum copper values can be used as an indicator of some pathological pregnancies.

  11. Copper (II) Removal In Anaerobic Continuous Column Reactor System By Using Sulfate Reducing Bacteria

    Science.gov (United States)

    Bilgin, A.; Jaffe, P. R.

    2017-12-01

    Copper is an essential element for the synthesis of the number of electrons carrying proteins and the enzymes. However, it has a high level of toxicity. In this study; it is aimed to treat copper heavy metal in anaerobic environment by using anaerobic continuous column reactor. Sulfate reducing bacteria culture was obtained in anaerobic medium using enrichment culture method. The column reactor experiments were carried out with bacterial culture obtained from soil by culture enrichment method. The system is operated with continuous feeding and as parallel. In the first rector, only sand was used as packing material. The first column reactor was only fed with the bacteria nutrient media. The same solution was passed through the second reactor, and copper solution removal was investigated by continuously feeding 15-600 mg/L of copper solution at the feeding inlet in the second reactor. When the experiment was carried out by adding the 10 mg/L of initial copper concentration, copper removal in the rate of 45-75% was obtained. In order to determine the use of carbon source during copper removal of mixed bacterial cultures in anaerobic conditions, total organic carbon TOC analysis was used to calculate the change in carbon content, and it was calculated to be between 28% and 75%. When the amount of sulphate is examined, it was observed that it changed between 28-46%. During the copper removal, the amounts of sulphate and carbon moles were equalized and more sulfate was added by changing the nutrient media in order to determine the consumption of sulphate or carbon. Accordingly, when the concentration of added sulphate is increased, it is calculated that between 35-57% of sulphate is spent. In this system, copper concentration of up to 15-600 mg / L were studied.

  12. Research on the effect of alkali roasting of copper dross on leaching rate of indium

    Science.gov (United States)

    Dafang, Liu; Fan, Xingxiang; Shi, Yifeng; Yang, Kunbin

    2017-11-01

    The byproduct copper dross produced during refining crude lead was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and fluorescence spectrometer (XRF), which showed that copper dross mainly contained lead, copper, zinc, arsenic, antimony, bismuth, sulfur and a small amount of indium and silver etc. The mineralogical phase change of oxidation roasting of copper dross by adding sodium hydroxide was analyzed with the help of XRD and SEM. The effects of water leaching, ratio of sodium hydroxide, roasting time, and roasting temperature on leaching rate of indium were investigated mainly. The experimental results showed that phase of lead metal and sulfides of lead, copper and zinc disappeared after oxidation roasting of copper dross by adding sodium hydroxide, new phase of oxides of lead, copper, zinc and sodium salt of arsenic and antimony appeared. Water leaching could remove arsenic, and acid leaching residue obtained was then leached with acid. The leaching rate of indium was higher 6.98% compared with alkali roasting of copper dross-acid leaching. It showed that removing arsenic by water leaching and acid leaching could increase the leaching rate of indium and be beneficial to reducing subsequent acid consumption of extracting indium by acid leaching. The roasting temperature had a significant effect on the leaching rate of indium, and leaching rate of indium increased with the rise of roasting temperature. When roasting temperature ranged from 450°C to 600°C, leaching rate of indium increased significantly with the rise of roasting temperature. When roasting temperature rose from 450°C to 600°C, leaching rate of indium increased by 60.29%. The amount of sodium hydroxide had an significant effect on the leaching rate of indium, and the leaching of indium increased with the increase of the amount of sodium hydroxide, and the leaching rate of indium was obviously higher than that of copper dross blank roasting and acid leaching.

  13. Facile preparation of monodisperse, impurity-free, and antioxidation copper nanoparticles on a large scale for application in conductive ink.

    Science.gov (United States)

    Zhang, Yu; Zhu, Pengli; Li, Gang; Zhao, Tao; Fu, Xianzhu; Sun, Rong; Zhou, Feng; Wong, Ching-ping

    2014-01-08

    Monodisperse copper nanoparticles with high purity and antioxidation properties are synthesized quickly (only 5 min) on a large scale (multigram amounts) by a modified polyol process using slightly soluble Cu(OH)2 as the precursor, L-ascorbic acid as the reductant, and PEG-2000 as the protectant. The resulting copper nanoparticles have a size distribution of 135 ± 30 nm and do not suffer significant oxidation even after being stored for 30 days under ambient conditions. The copper nanoparticles can be well-dispersed in an oil-based ink, which can be silk-screen printed onto flexible substrates and then converted into conductive patterns after heat treatment. An optimal electrical resistivity of 15.8 μΩ cm is achieved, which is only 10 times larger than that of bulk copper. The synthesized copper nanoparticles could be considered as a cheap and effective material for printed electronics.

  14. Silane pre-treatments on copper and aluminium

    International Nuclear Information System (INIS)

    Deflorian, F.; Rossi, S.; Fedrizzi, L.

    2006-01-01

    A large part of aluminium products are coated with an organic layer in order to improve the corrosion resistance. Copper surfaces are also sometimes protected with an organic coating to improve the durability or the aesthetic properties. Examples of industrial applications are household appliances and heat exchanger components. For these applications it is not rare to have the industrial need to treat at the same time components made of aluminium and copper. In order to extend the service life of the organic coated copper a specific surface pre-treatment is often required. Nevertheless, probably because of the limited market of this application, no specific pre-treatments for copper are industrially developed, with the exception of cleaning procedures, but simply extensions of existing pre-treatments optimised for other metals (aluminium, zinc) are used. The application of silane pre-treatments as adhesion promoters for organic coated metals is remarkably increasing in the last decade, because silanes offer very good performance together with high environmental compatibility. The idea is therefore to try to develop a specific silane based pre-treatment for copper. The starting point is the existing silane products for aluminium, optimising the composition and the application conditions (concentration, temperature, pH of the bath, etc.) in order to develop a high performance copper alloy pre-treatment increasing the protective properties and the adhesion of a successively applied organic coating. Moreover these pre-treatments could be used for aluminium alloys too and therefore could be suggested for multi-metals components. The deposits were analysed using FTIR spectroscopy and optical and electron microscopic observations. A careful electrochemical characterisation, mainly by electrochemical impedance spectroscopy measurements (EIS) was carried out to highlight the presence of silane and to evaluate the performance of the different deposits. In order to study an

  15. A Plasmodium falciparum copper-binding membrane protein with copper transport motifs

    Directory of Open Access Journals (Sweden)

    Choveaux David L

    2012-11-01

    Full Text Available 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 still remains to be fully elucidated. Methods PlasmoDB was searched for sequences corresponding to candidate P. falciparum copper-requiring proteins. The amino terminal domain of a putative P. falciparum copper transport protein was cloned and expressed as a maltose binding fusion protein. The copper binding ability of this protein was examined. Copper transport protein-specific anti-peptide antibodies were generated in chickens and used to establish native protein localization in P. falciparum parasites by immunofluorescence microscopy. Results Six P. falciparum copper-requiring protein orthologs and a candidate P. falciparum copper transport protein (PF14_0369, containing characteristic copper transport protein features, were identified in PlasmoDB. The recombinant amino terminal domain of the transport protein bound reduced copper in vitro and within Escherichia coli cells during recombinant expression. Immunolocalization studies tracked the copper binding protein translocating from the erythrocyte plasma membrane in early ring stage to a parasite membrane as the parasites developed to schizonts. The protein appears to be a PEXEL-negative membrane protein. Conclusion Plasmodium falciparum parasites express a native protein with copper transporter characteristics that binds copper in vitro. Localization of the protein to the erythrocyte and parasite plasma membranes could provide a mechanism for the delivery of novel anti-malarial compounds.

  16. Development of polypyrrole coated copper nanowires for gas sensor application

    Directory of Open Access Journals (Sweden)

    H. Shokry Hassan

    2015-09-01

    Full Text Available Both polypyrrole (PPy and polypyrrole coated copper thin films were synthesized successfully via two-step methods. PPy nanorods films were first grown chemically, and then PPy thin films were fabricated on glass substrates using dip-coating technique. The resulting films were examined via various characterization methods such as X-ray diffraction (XRD, scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FT-IR and Thermal Gravimetric Analysis (TGA. Gas sensor devices were fabricated and the gas sensitivity for (PPy coated copper was measured as a function of temperature for both O2 and CO2 gases. The maximum sensitivity for O2 gas was around 160% and the maximum sensitivity for CO2 was 300%.

  17. Copper nanoparticles synthesized in polymers by ion implantation

    DEFF Research Database (Denmark)

    Popok, Vladimir; Nuzhdin, Vladimir; Valeev, Valerij

    2015-01-01

    Polymethylmethacrylate (PMMA) and polyimide (PI) samples are implanted by 40 keV Cu+ ions with high fluences in order to synthesize copper nanoparticles in shallow polymer layers. The produced metal/polymer nanocomposites are studied using atomic force and scanning electron microscopies as well...... as optical transmission spectroscopy. It is found that copper nanoparticles nucleation and growth are strongly fluence dependent as well as they are affected by the polymer properties, in particular, by radiation stability yielding different nanostructures for the implanted PI and PMMA. Shallow synthesized...... nanoparticles are observed to partly tower above the sample surface due to a side effect of high-fluence irradiation leading to considerable sputtering of polymers. Implantation and particle formation significantly change optical properties of both polymers reducing transmittance in the UV-visible range due...

  18. Grain boundary embrittlement and cohesion enhancement in copper

    Energy Technology Data Exchange (ETDEWEB)

    Paxton, Anthony; Lozovoi, Alexander [Atomistic Simulation Centre, Queen' s University Belfast, BT7 1NN (United Kingdom); Schweinfest, Rainer [Science+Computing ag, Hagellocher Weg 71-5, 720270 T ubingen (Germany); Finnis, Michael [Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)

    2008-07-01

    There has been a long standing debate surrounding the mechanism of grain boundary embrittlement and cohesion enhancement in metals. Embrittlement can lead to catastrophic failure such as happened in the Hinkley Point disaster, or indeed in the case of the Titanic. This kind of embrittlement is caused by segregation of low solubility impurities to grain boundaries. While the accepted wisdom is that this is a phenomenon driven by electronic or chemical factors, using language such as charge transfer and electronegativity difference; we believe that in copper, at least, both cohesion enhancement and reduction are caused by a simple size effect. We have developed a theory that allows us to separate unambiguously, if not uniquely, chemical and structural factors. We have studied a large number of solutes in copper using first principles atomistic simulation to support this argument, and the results of these calculations are presented here.

  19. Facile Synthesis of Copper Oxide Nanoparticles via Electrospinning

    Directory of Open Access Journals (Sweden)

    Abdullah Khalil

    2014-01-01

    Full Text Available A novel approach for synthesizing copper oxide (CuO nanoparticles (NPs through electrospinning is reported. The approach is based on producing rough and discontinuous electrospun nanofibers from a precursor based on copper acetate salt and polyvinyl alcohol (PVA polymer. Selectively removing the polymeric phase from the fibers produced highly rough CuO nanofibers, which were composed of NPs that are weakly held together in a one-dimensional (1D manner. Sonication in a suitable liquid under controlled conditions completely disintegrated the nanofibers into NPs, resulting in the formation of uniform CuO NPs suspension. Aberration corrected high resolution transmission electron microscope (HRTEM showed that the obtained NPs are highly crystalline and nearly sphere-like with a diameter of 30 to 70 nm. Thus, electrospinning, which is a low cost and industrially scalable technique, can also be employed for economic and large scale synthesis of NPs.

  20. Recent structural insights into the function of copper nitrite reductases.

    Science.gov (United States)

    Horrell, Sam; Kekilli, Demet; Strange, Richard W; Hough, Michael A

    2017-11-15

    Copper nitrite reductases (CuNiR) carry out the first committed step of the denitrification pathway of the global nitrogen cycle, the reduction of nitrite (NO 2 - ) to nitric oxide (NO). As such, they are of major agronomic and environmental importance. CuNiRs occur primarily in denitrifying soil bacteria which carry out the overall reduction of nitrate to dinitrogen. In this article, we review the insights gained into copper nitrite reductase (CuNiR) function from three dimensional structures. We particularly focus on developments over the last decade, including insights from serial femtosecond crystallography using X-ray free electron lasers (XFELs) and from the recently discovered 3-domain CuNiRs.

  1. Microstructure and Mechanical Properties of Graphene Oxide/Copper Composites

    Directory of Open Access Journals (Sweden)

    HONG Qi-hu

    2016-09-01

    Full Text Available Graphene oxide/copper (GO/Cu composites were successfully synthesized through the ball milling and vacuum hot press sintering process. The morphologies of the mixture powders, and the microstructure and mechanical properties of GO/Cu composites were investigated by OM, SEM, XRD, hardness tester and electronic universal testing machine, respectively. The results show that the GO/Cu composites are compact. Graphene oxide with flake morphology is uniformly dispersed and well consolidated with copper matrix. When the mass fraction of graphene oxide is 0.5%, the microhardness and compress strength at RT reach up to 63HV and 276MPa, increased by 8.6% and 28%, respectively. The strengthening mechanism is load transfer effect, dislocation strengthening and fine crystal reinforcing.

  2. Adsorption of aqueous copper on peanut hulls

    Science.gov (United States)

    Davis, Kanika Octavia

    , scanning electron microscopy images coupled with energy dispersive X-ray spectroscopy showed that the percentage of copper on the modified hulls (2.5 %) was greater than on the unmodified hulls (1.6 %). This study concluded that the adsorption of copper using peanut hulls is a potential method for wastewater treatment and delignification and oxidation of the hulls increases the adsorption capacity approximately three-fold.

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

    Science.gov (United States)

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

    2008-08-29

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

  4. Experimental Investigation on the Mechanism of Chelation-Assisted, Copper(II) Acetate-Accelerated Azide-Alkyne Cycloaddition

    Science.gov (United States)

    Kuang, Gui-Chao; Guha, Pampa M.; Brotherton, Wendy S.; Simmons, J. Tyler; Stankee, Lisa A.; Nguyen, Brian T.; Clark, Ronald J.; Zhu, Lei

    2011-01-01

    A mechanistic model is formulated to account for the high reactivity of chelating azides (organic azides capable of chelation-assisted metal coordination at the alkylated azido nitrogen position) and copper(II) acetate (Cu(OAc)2) in copper(II)-mediated azide-alkyne cycloaddition (AAC) reactions. Fluorescence and 1H NMR assays are developed for monitoring the reaction progress in two different solvents – methanol and acetonitrile. Solvent kinetic isotopic effect and pre-mixing experiments give credence to the proposed different induction reactions for converting copper(II) to catalytic copper(I) species in methanol (methanol oxidation) and acetonitrile (alkyne oxidative homocoupling), respectively. The kinetic orders of individual components in a chelation-assisted, copper(II)-accelerated AAC reaction are determined in both methanol and acetonitrile. Key conclusions resulting from the kinetic studies include (1) the interaction between copper ion (either in +1 or +2 oxidation state) and a chelating azide occurs in a fast, pre-equilibrium step prior to the formation of the in-cycle copper(I)-acetylide, (2) alkyne deprotonation is involved in several kinetically significant steps, and (3) consistent with prior experimental and computational results by other groups, two copper centers are involved in the catalysis. The X-ray crystal structures of chelating azides with Cu(OAc)2 suggest a mechanistic synergy between alkyne oxidative homocoupling and copper(II)-accelerated AAC reactions, in which both a bimetallic catalytic pathway and a base are involved. The different roles of the two copper centers (a Lewis acid to enhance the electrophilicity of the azido group and a two-electron reducing agent in oxidative metallacycle formation, respectively) in the proposed catalytic cycle suggest that a mixed valency (+2 and +1) dinuclear copper species be a highly efficient catalyst. This proposition is supported by the higher activity of the partially reduced Cu(OAc)2 in

  5. Symmetry in copper and silver cryptates

    International Nuclear Information System (INIS)

    The cryptand ligands imBT (1,4,7,10,13,16,21, 24-0ctaa2a-bicyclo [8.8.8]hexacosa- 4,6,13,15,21,23-hexaene) and amBT (1,4,7,10,13,16,21,24-Octaaza- bicyclo[8.8.8]hexacosane) form interesting disilver(I) and trisilver(l) cryptates, as well as a dicopper(I) and a well studied average valence dicopper(1.5) cryptate. Detailed structural and spectroscopic studies of the silver cryptates show that complex equilibria exist in solution, and the trisilver form appears to be thermodynamically favoured, the additional stabilisation apparently being due to argentophilic interactions. An optically pure form of the dicopper(I) imBT cryptate was successfully obtained, and is undergoing X-ray diffraction studies aimed at determining whether a copper-copper interaction exists, by direct examination of the electron density. Synthetic studies aimed at introducing substitution to the imBT and amBT ligands were complicated by competing reactions. A strategy to modify cryptand cavity size by incorporating asymmetric tetraamine caps succeeded, yielding dicopper(I) and disilver(I) cryptates with properties intermediate between cryptates incorporating the related symmetric caps. Manganese(II) cryptates of imBT and amBT were investigated as potential MRI contrast agents, the iminocryptate showing surprisingly high relaxivity, despite the fact that no water molecules were located in the crystal structure. The observation of high mass peaks in the FAB mass spectra of imBT and amBT cryptates suggests the presence of 6+4 Schiffbase condensation products, as well as the more abundant 3+2 products. It has not proved possible to isolate these molecules as yet, however initial studies aimed at a rational synthesis of the 6+4 condensation products were made, as these ligands could be of great interest for modelling the recently reported Cu z site. (author)

  6. Copper-based nanoparticles prepared from copper (II acetate bipyridine complex

    Directory of Open Access Journals (Sweden)

    Lastovina Tatiana A.

    2016-01-01

    Full Text Available We report the synthesis of CuO, Cu/Cu2O and Cu2O/CuO nanoparticles (NPs from the single copper (II acetate bipyridine complex by three different methods:microwave-assisted, solvothermal and borohydride. Presence of bipyridine ligand in the copper complex would impose no need in additional stabilization during synthesis. The phases of formed NPs were identified by X-ray diffraction. CuO NPs of ~11 nm were obtained via solvothermal synthesis from alkaline solution at 160°C. The Cu/Cu2O NPs of ~80 nm were produced via microwave-assisted polyol procedure at 185-200°C, where ethylene glycol can play a triple role as a solvent, a reducing agent and a surfactant. The Cu2O/CuO NPs of ~16 nm were synthesized by a borohydride method at room temperature. Interplanar spacing calculated from the selected-area electron diffraction data confirmed the formation of Cu, CuO and Cu2O phases in respective samples. All NPs are stable and can be used for various applications including biomedicine.

  7. Thermal Stability of Copper-Aluminum Alloy Thin Films for Barrierless Copper Metallization on Silicon Substrate

    Science.gov (United States)

    Wang, C. P.; Dai, T.; Lu, Y.; Shi, Z.; Ruan, J. J.; Guo, Y. H.; Liu, X. J.

    2017-08-01

    Copper thin films with thickness of about 500 nm doped with different aluminum concentrations have been prepared by magnetron sputtering on Si substrate and their crystal structure, microstructure, and electrical resistivity after annealing at various temperatures (200°C to 600°C) for 1 h or at 400°C for different durations (1 h to 11 h) investigated by grazing-incidence x-ray diffraction (GIXRD) analysis, scanning electron microscopy (SEM), and four-point probe (FPP) measurements. Cu-1.8Al alloy thin film exhibited good thermal stability and low electrical resistivity (˜5.0 μΩ cm) after annealing at 500°C for 1 h or 400°C for 7 h. No copper silicide was observed at the Cu-Al/Si interface by GIXRD analysis or SEM for this sample. This result indicates that doping Cu thin film with small amounts of Al can achieve high thermal stability and low electrical resistivity, suggesting that Cu-1.8Al alloy thin film could be used for barrierless Cu metallization on Si substrate.

  8. Electrochemical in-situ impregnation of wood using a copper nail as source for copper

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Block, Thomas; Nymark, Morten

    2011-01-01

    A new method for copper impregnation of wood in structures was suggested and tested in laboratory scale with specimen of new pine sapwood. A copper nail and a steel screw were placed in the wood, and an electric direct current field was applied, so the copper nail was anode and the screw...... was cathode. At the anode, copper ions were generated. The copper ions were transported into the wood by electromigration (movement of ions in an applied electric field) towards the cathode, and a volume between the two electrodes was thereby impregnated. Copper also moved to a lesser degree in the opposite...

  9. Ammonia leaching of copper smelter dust and precipitation as copper sulphide

    International Nuclear Information System (INIS)

    Morales, A.; Hevia, J. F.; Cifuentes, G.

    2009-01-01

    The effect of ammonia on the leaching of copper smelter dust and copper precipitation from these solutions as sulphide using sulfur and sulfur dioxide was studied. The precipitation was done in ammoniacal media because this solution produced more satisfactory results at room temperature that a sulphuric media. A solid was precipitated containing 60 % of copper of the dust smelter. The other waste generated contained around 80 % of the arsenic of the original copper smelter dust. Based on the preliminary results obtained in this work it will propose a procedure for the recovery of copper as sulphide from copper smelter dust with parallel confinement of arsenic. (Author) 14 refs.

  10. All-inorganic large-area low-cost and durable flexible perovskite solar cells using copper foil as a substrate.

    Science.gov (United States)

    Abdollahi Nejand, B; Nazari, P; Gharibzadeh, S; Ahmadi, V; Moshaii, A

    2017-01-05

    Here, a low-cost perovskite solar cell using CuI and ZnO as the respective inorganic hole and electron transport layers is introduced. Copper foil is chosen as a cheap and low-weight conductive substrate which has a similar work function to ITO. Besides, copper foil is an interesting copper atom source for the growth of the upper cuprous iodide layer on copper foil. A spray coating of a transparent silver nanowire electrode is used as a top contact. The prepared device shows a maximum power conversion efficiency of 12.80% and long-term durability providing an environmentally and market friendly perovskite solar cell.

  11. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  12. Canine Models for Copper Homeostasis Disorders

    Directory of Open Access Journals (Sweden)

    Xiaoyan Wu

    2016-02-01

    Full Text Available 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 metabolism, the underlying genetic defects remain elusive. Several pure bred dog populations are affected with copper-associated hepatitis showing similarities to human copper metabolism disorders. Gene-mapping studies in these populations offer the opportunity to discover new genes involved in copper metabolism. Furthermore, due to the relatively large body size and long life-span of dogs they are excellent models for development of new treatment strategies. One example is the recent use of canine organoids for disease modeling and gene therapy of copper storage disease. This review addresses the opportunities offered by canine genetics for discovery of genes involved in copper metabolism disorders. Further, possibilities for the use of dogs in development of new treatment modalities for copper storage disorders, including gene repair in patient-derived hepatic organoids, are highlighted.

  13. Thermal conductivity of glass copper-composite

    International Nuclear Information System (INIS)

    Kinoshita, Makoto; Terai, Ryohei; Haidai, Haruki

    1980-01-01

    Glass-metal composites are to be one of the answers for promoting thermal conduction in the glassy solids containing high-level radioactive wastes. In order to investigate the effect of metal addition on thermal conductivity of glasses, glass-copper composites were selected, and the conductivities of the composites were measured and discussed in regards to copper content and microstructure. Fully densified composites were successfully prepared by pressure sintering of the powder mixtures of glass and copper at temperatures above the yield points of the constituent glasses if the copper content was not so much. The conductivity was measured by means of a comparative method, in which the thermal gradient of the specimen was compared with that of quartz glass as standard under thermally steady state. Measurements were carried out at around 50 0 C. The thermal conductivity increased with increasing content of copper depending on the kind of copper powder used. The conductivities of the composites of the same copper content differed considerably each another. Fine copper powder was effective on increasing conductivity, and the conductivity became about threefold of that of glass by mixing the fine copper powder about 10 vol%. For the composites containing the fine copper powder less than 5 vol%, the conductivity obeyed so-called logarithmic rule, one of the mixture rules of conductivity, whereas for composites containing more than 5 vol%, the conductivity remarkably increased apart from the rule. This fact suggests that copper becomes continuous in the composite when the copper content increased beyond 5 vol%. For the composites containing coarse copper powder, the conductivity was increased not significantly, and obeyed an equation derived from the model in which conductive material dispersed in less conductive one. (author)

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

    Science.gov (United States)

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

    2011-01-01

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

  15. Fabrication and characterization of silver- and copper-coated Nylon 6 forcespun nanofibers by thermal evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Mihut, Dorina M., E-mail: dorinamm@yahoo.com; Lozano, Karen [Department of Mechanical Engineering, The University of Texas Pan American, 1201 W University Drive, Edinburg, Texas 78539 (United States); Foltz, Heinrich [Department of Electrical Engineering, The University of Texas Pan American, 1201 W University Drive, Edinburg, Texas 78539 (United States)

    2014-11-01

    Silver and copper nanoparticles were deposited as thin films onto substrates consisting of Nylon 6 nanofibers manufactured using forcespinning{sup ®} equipment. Different rotational speeds were used to obtain continuous nanofibers of various diameters arranged as nonwoven mats. The Nylon 6 nanofibers were collected as successive layers on frames, and a high-vacuum thermal evaporation method was used to deposit the silver and copper thin films on the nanofibers. The structures were investigated using scanning electron microscopy–scanning transmission electron microscopy, atomic force microscopy, x-ray diffraction, and electrical resistance measurements. The results indicate that evaporated silver and copper nanoparticles were successfully deposited on Nylon 6 nanofibers as thin films that adhered well to the polymer substrate while the native morphology of the nanofibers were preserved, and electrically conductive nanostructures were achieved.

  16. Band structure and phase stability of the copper oxides Cu2O, CuO, and Cu4O3

    Science.gov (United States)

    Heinemann, Markus; Eifert, Bianca; Heiliger, Christian

    2013-03-01

    The p-type semiconductor copper oxide has three distinct phases Cu2O, CuO, and Cu4O3 with different morphologies and oxidation states of the copper ions. We investigate the structural stability and electronic band structure of all three copper oxide compounds using ab initio methods within the framework of density functional theory and consider different exchange correlation functionals. While the local density approximation (LDA) fails to describe the semiconducting states of CuO and Cu4O3, the LDA+U and HSE06 hybrid functional describe both compounds as indirect semiconductors. Using the HSE06 hybrid functional we calculate the electronic band structure in the full Brillouin zone for all three copper oxide compounds.

  17. Oxidation of copper nanowire based transparent electrodes in ambient conditions and their stabilization by encapsulation: application to transparent film heaters

    Science.gov (United States)

    Celle, Caroline; Cabos, Anthony; Fontecave, Thomas; Laguitton, Bruno; Benayad, Anass; Guettaz, Laure; Pélissier, Nathalie; Huong Nguyen, Viet; Bellet, Daniel; Muñoz-Rojas, David; Simonato, Jean-Pierre

    2018-02-01

    Whereas the integration of silver nanowires in functional devices has reached a fair level of maturity, the integration of copper nanowires still remains difficult, mainly due to the intrinsic instability of copper nanowires in ambient conditions. In this paper, copper nanowire based transparent electrodes with good performances (33 Ω sq-1 associated with 88% transparency) were obtained, and their degradation in different conditions was monitored, in particular by electrical measurements, transmission electron microscopy, x-ray photoelectron spectrometry and Auger electron spectroscopy. Several routes to stabilize the random networks of copper nanowires were evaluated. Encapsulation through laminated barrier film with optical clear adhesive and atmospheric pressure spatial atomic layer deposition were found to be efficient and were used for the fabrication of transparent film heaters.

  18. Diffusion-controlled intergranular penetration and embrittlement of copper by liquid bismuth between 300 and 600 Celsius degrees

    International Nuclear Information System (INIS)

    Laporte, V.

    2005-02-01

    Hybrid reactors are a new concept for energy production and nuclear waste treatment. Among other requirements, structural materials have to withstand liquid metal embrittlement. This thesis aimed therefore to identify the controlling mechanism for the intergranular embrittlement of copper in contact with liquid bismuth. Scanning electron microscopy, Auger electron spectroscopy, X-ray photoelectron spectroscopy and Rutherford backscattering spectroscopy have been used to analyze fracture surfaces of both copper polycrystals and a copper bicrystal (symmetric tilt boundary 50 degrees ). These analyses reveal both parabolic intergranular penetration kinetics and a maximal intergranular bismuth concentration that is less than two monolayers equivalent. These two results allow us to identify grain boundary diffusion as the controlling mechanism for the intergranular penetration of copper by liquid bismuth between 300 and 600 Celsius degrees, showing the absence of perfect grain boundary wetting. (author)

  19. Conductivity of laser printed copper structures limited by nano-crystal grain size and amorphous metal droplet shell

    International Nuclear Information System (INIS)

    Winter, Shoshana; Zenou, Michael; Kotler, Zvi

    2016-01-01

    We present a study of the morphology and electrical properties of copper structures which are printed by laser induced forward transfer from bulk copper. The percentage of voids and the oxidation levels are too low to account for the high resistivities (∼4 to 14 times the resistivity of bulk monocrystalline copper) of these structures. Transmission electron microscope (TEM) images of slices cut from the printed areas using a focused ion beam (FIB) show nano-sized crystal structures with grain sizes that are smaller than the electron free path length. Scattering from such grain boundaries causes a significant increase in the resistivity and can explain the measured resistivities of the structures. The TEM images also show a nano-amorphous layer (∼5 nm) at the droplet boundaries which also contributes to the overall resistivity. Such morphological characteristics are best explained by the ultrafast cooling rate of the molten copper droplets during printing. (paper)

  20. Low-cost optical fabrication of flexible copper electrode via laser-induced reductive sintering and adhesive transfer

    Science.gov (United States)

    Back, Seunghyun; Kang, Bongchul

    2018-02-01

    Fabricating copper electrodes on heat-sensitive polymer films in air is highly challenging owing to the need of expensive copper nanoparticles, rapid oxidation of precursor during sintering, and limitation of sintering temperature to prevent the thermal damage of the polymer film. A laser-induced hybrid process of reductive sintering and adhesive transfer is demonstrated to cost-effectively fabricate copper electrode on a polyethylene film with a thermal resistance below 100 °C. A laser-induced reductive sintering process directly fabricates a high-conductive copper electrode onto a glass donor from copper oxide nanoparticle solution via photo-thermochemical reduction and agglomeration of copper oxide nanoparticles. The sintered copper patterns were transferred in parallel to a heat-sensitive polyethylene film through self-selective surface adhesion of the film, which was generated by the selective laser absorption of the copper pattern. The method reported here could become one of the most important manufacturing technologies for fabricating low-cost wearable and disposable electronics.

  1. POWER PARAMETERS OF THE PROCESS OF END FORMING OF THICK WALLED TUBES

    Directory of Open Access Journals (Sweden)

    V. A. Tamila

    2016-01-01

    Full Text Available Analysis of forces acting on the rolls in the radial direction made by the analytical method and with use of computer modeling techniques is made. Application of FEM has allowed to calculate distribution of power parameters of the technological process during time. The deviation of the experimental data on the results of analytical calculation is within 3%.

  2. Explosive cutting of thick-walled steel pipes in the reactor HDR

    International Nuclear Information System (INIS)

    Wegener, H.; Freund, H.U.

    1990-01-01

    Cutting of a real pipe system by explosive technique has been tested and proven feasible inside the HDR reactor containment. Circumferential cuts were performed on a pipe loop with 400 mm diameter, 20 mm wall thickness. The cutting tool consists of an array of modular explosive charges which are wrapped around the pipe in a collar like mode. Mounting of the charge array is performed manually in a quick and easy way. In order to retain the fragments originating from the charge a fragment retaining structure was used in the experiments. This ring shape structure (fragment catcher) also substantially reduces the explosive blast load on the immediate vicinity. However, handling a fragment catcher of 700 kg weight requires a pulley or crane and, consequently, rather restricts the application of this technique. In addition to the control of the fragments and the blast wave in the area of cutting operation the transient load on the pipe system and on the reactor containment structure has to be kept below critical values. In principle, the load produced in pipe cutting by explosive methods must be subdivided into the local and the global loads acting on the HDR. The various contributions of the dynamic loading have been measured and analyzed carefully. Fourier analyses conducted on the basis of displacement measurements indicate the frequencies. The ground mode, of the long pipe branch are between 2.5 Hz and 3.5 Hz, and for the second ground mode, between 7.5 Hz and 8.5 Hz. Predictions of the axial momentum on the basis of short pipe segment cutting are a factor of 3 too high in the calculated deflection of the separated pipe ends, while the calculated pipe excitation frequencies (2.5 to 10 Hz) are in rather good agreement with the measurement. (orig./GL)

  3. Repair weld induced residual stresses in thick-walled steel pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.C.; Holz, P.P.

    1978-06-01

    If a flaw requiring corrective action were to be found in an operating nuclear pressure vessel, there would be considerable safety and economic implications. Should such a flaw be found, one possible corrective action would be an in situ repair weld. A repair of this type would presumably involve grinding away material in a region encompassing the flaw and then filling the resulting cavity with weld metal. Thermal stress relieving under those conditions could lead to serious difficulties associated with thermal expansion and warpage and would therefore most likely be avoided. Such a departure from normal procedure raises questions relating to residual stresses and material toughness levels which would have to be assessed before a repair could be recommended or approved. The residual stress measurements reported are intended to provide baseline information to aid in an assessment should such a repair ever have to be seriously considered.

  4. Thick-Walled Cylinder Theory Applied on a Conical Wedge Anchorage

    DEFF Research Database (Denmark)

    Bennitz, Anders; Grip, Niklas; Schmidt, Jacob Wittrup

    2011-01-01

    Conical wedge anchorages are frequently used to anchor steel tendons in prestressing applications within the construction industry. To replace the steel tendons with non-corrosive and low weight FRPs (Fiber Reinforced Polymers), the different mechanical interactions between the steel and FRPs call...

  5. Free and Forced Vibrations of Thick-Walled Anisotropic Cylindrical Shells

    Science.gov (United States)

    Marchuk, A. V.; Gnedash, S. V.; Levkovskii, S. A.

    2017-03-01

    Two approaches to studying the free and forced axisymmetric vibrations of cylindrical shell are proposed. They are based on the three-dimensional theory of elasticity and division of the original cylindrical shell with concentric cross-sectional circles into several coaxial cylindrical shells. One approach uses linear polynomials to approximate functions defined in plan and across the thickness. The other approach also uses linear polynomials to approximate functions defined in plan, but their variation with thickness is described by the analytical solution of a system of differential equations. Both approaches have approximation and arithmetic errors. When determining the natural frequencies by the semi-analytical finite-element method in combination with the divide and conqure method, it is convenient to find the initial frequencies by the finite-element method. The behavior of the shell during free and forced vibrations is analyzed in the case where the loading area is half the shell thickness

  6. SMILE: test to validate the WPS effect with a cylindrical thick-walled specimen

    Energy Technology Data Exchange (ETDEWEB)

    Bezdikian, G. [Electricite de France, EDF DPN, Saint-Denis (France); Moinereau, D. [Electricite de France, EDF-R and D, Moret-sur-Loing (France); Roos, E.; Kerkhof, K. [MPA, Stuttgart (Germany); Taylor, N. [Joint Research Centre, Inst. for Energy, Petten (Netherlands)

    2004-07-01

    The Reactor Pressure Vessel (RPV) is an essential component, which is liable to limit the lifetime duration of PWR plants. The assessment of defects in RPV subjected to pressurized thermal shock (PTS) transients made at an European level generally does not necessarily consider the beneficial effect of the load history (Warm Pre-stress, WPS). The SMILE project - Structural Margin Improvements in aged embrittled RPV with Load history Effects - aims to give sufficient elements to demonstrate, to model and to validate the beneficial WPS effect. It also aims to harmonize the different approaches in the national codes and standards regarding the inclusion of the WPS effect in a RPV structural integrity assessment. The project includes significant experimental work on WPS type experiments with C(T) specimens and a PTS type transient experiment on a large component. This paper deals with the results of the PTS type transient experiment on a component-like, specimen subjected to WPS-loading, the so called Validation Test, carried out within the framework of work package WP4. The test specimen consists of a cylindrical thickwalled specimen with a thickness of 40 mm and an outer diameter of 160 mm, provided with an internal fully circumferential crack with a depth of about 15 mm. The specified load path type is Load-Cool-Unload-Fracture (LCUF). (orig.)

  7. Evaluations of half-bead weld repair procedures with thick-wall pressure vessels

    International Nuclear Information System (INIS)

    Canonico, D.A.; Whitman, G.D.

    1978-01-01

    The results of research on the evaluation of the half-bead weld repair method for use on nuclear reactor components are reviewed from data obtained on thick-section test pieces and intermediate-size pressure vessels. Material properties, the magnitude of residual stresses and the structural behavior of flawed pressure vessels are being obtained to determine the adequacy of the weld repair method for application in thick-section components

  8. Study of brittle fracture in thick walled structures using small and large specimens

    International Nuclear Information System (INIS)

    Norrthon, J.-O.; Carlsson, J.

    1979-01-01

    A Russian pressure vessel steel has been investigated for fracture toughness data, Ksub(Ic) and Jsub(Ic). Four large specimens have been tested and the results correlated to data from several smaller specimens. Onset of crack growth has been detected by a high frequency electric method. (author)

  9. SMILE: test to validate the WPS effect with a cylindrical thick-walled specimen

    International Nuclear Information System (INIS)

    Bezdikian, G.; Moinereau, D.; Roos, E.; Kerkhof, K.; Taylor, N.

    2004-01-01

    The Reactor Pressure Vessel (RPV) is an essential component, which is liable to limit the lifetime duration of PWR plants. The assessment of defects in RPV subjected to pressurized thermal shock (PTS) transients made at an European level generally does not necessarily consider the beneficial effect of the load history (Warm Pre-stress, WPS). The SMILE project - Structural Margin Improvements in aged embrittled RPV with Load history Effects - aims to give sufficient elements to demonstrate, to model and to validate the beneficial WPS effect. It also aims to harmonize the different approaches in the national codes and standards regarding the inclusion of the WPS effect in a RPV structural integrity assessment. The project includes significant experimental work on WPS type experiments with C(T) specimens and a PTS type transient experiment on a large component. This paper deals with the results of the PTS type transient experiment on a component-like, specimen subjected to WPS-loading, the so called Validation Test, carried out within the framework of work package WP4. The test specimen consists of a cylindrical thickwalled specimen with a thickness of 40 mm and an outer diameter of 160 mm, provided with an internal fully circumferential crack with a depth of about 15 mm. The specified load path type is Load-Cool-Unload-Fracture (LCUF). (orig.)

  10. Ultrasonic measurements on residual stress in autofrettged thick walled petroleum pipes

    International Nuclear Information System (INIS)

    Woias, G.; Mizera, J.

    2008-01-01

    The residual stresses in a component or structure are caused by incompatible permanent deformation and related gradient of plastic/elastic strains. They may be generated or modified at every stage in the components life cycle, from original material production to final disposal. Residual stresses can be measured by non-destructive techniques, including X-ray and neutron diffraction, magnetic and ultrasonic methods. The selection of the optimum measurement technique should take account volumetric resolution, material, geometry and access to the component. For large metallic components neutron diffraction is of prime importance as it provides quantitative information on stresses in relatively large volume of methods disregarding its shape complexity. Residual stresses can play a significant role in explaining or preventing failure of components of industrial installations. One example of residual stresses preventing failure are the ones generated by shot peening, inducing surface compressive stresses that improve the fatigue life. Petroleum refinery piping is generally characterized by large-diameters, operated at elevated temperature and under high pressure. Pipelines of a polyethylene plant working in one of the Polish refineries are subjected to pressures exceeding 300 MPa at temperatures above 200 o C. The pipes considered here were pressurized with pressure of 600 MPa. The wall thickness of the pipes is 27 mm and pipe dimensions are 46 x 100 mm. The material is steel with Re=580 MPa. Due to pressurizing, the components retain compressive stresses at the internal surface. These stresses increase resistance to cracking of the pipes. Over the period of exploitation these stresses diminish due to temperature activated relaxation or creep. The purpose of the project is to verify kinetics of such a relaxation process and calibrate alternative methods of their measurements. To avoid stress relaxation, numerical analysis from Finite Element Modelling (FEM)gave an optimal specimen length as 60 mm required beam time is for three slices measurements in depth of wall. This work is to compare the neutron stresses on ultrasound technique and FEM. Results of FEM modeling shows the axial compression zone in the inner side of the pipe. The residual stresses are growing while the pipe is in exploitation. Non-destructive method of measurements - ultrasonic - will be the best way of life time assessment and degradation monitoring. That's why the results obtained with other residual stresses measuring methods are significant. The measurements using neutron gauge are planned to be done on the inner surface of the pipe. According to the FEM model the dimensions of the sample to rule out any risk of residual stresses relaxation are described in inferences by FEM analysis. To assess residual stresses with 5% accuracy it is required to measure slice cut samples not less that two pipe's thickness length - 60 cm. Three samples were prepared to be measured: 1) New pipe after autofrettaging [Np]; 2) Pipe after exploitation from the upper part of the reactor - heating zone [11/1]; 3) Pipe from lower part - cooling zone [75]. In the first part of the experiment, the pipe no [11/1] has been measured for axial and hoop stresses. The pipe [Np] was measured for axial stresses. The aim of these measurements will be measuring hoop residual stress on a non-used pipe after autofrettaging [Np] as well as hoop and axial stresses in a pipe taken from the lower part of the reactor - the cooling zone. (author)

  11. Functional understanding of the versatile protein copper metabolism MURR1 domain 1 (COMMD1) in copper homeostasis

    NARCIS (Netherlands)

    Fedoseienko, Alina; Bartuzi, Paulina; van de Sluis, Bart

    2014-01-01

    Copper is an important cofactor in numerous biological processes in all living organisms. However, excessive copper can be extremely toxic, so it is vital that the copper level within a cell is tightly regulated. The damaging effect of copper is seen in several hereditary forms of copper toxicity in

  12. Hydrothermal crystallization of α-alumina monohydrate in the presence of copper ions

    Science.gov (United States)

    Brown, N.

    1989-09-01

    The effect of copper ions on the hydrothermal crystallization of α-alumina monohydrate (A1OOH, mineral name boehmite), following oxidation of the organic carbon compounds in sodium aluminate solution of the Bayer process, has been examined using scanning electron microscopy and particle size analyses. The initial effect of the copper ions on the homogeneously nucleated α-alumina monohydrate is to inhibit crystal growth on the (001) faces and direct the growth process to the prismatic faces of the rhombic or diamond shaped crystals. At low copper levels (up to 0.1 wt% in α-alumina monohydrate), this leads to the formation of plate-like crystals up to 25 μm in size which can intergrow and develop into particles with an average size of up to 100 μm. The size and structure of the μ-alumina monohydrate particles, however, depend on the amount of copper present and increasing copper levels (up to 1.0 wt%) lead progressively to a decrease in average particle size of α-alumina monohydrate to about 10 μm and the formation of more rounded oblong-shaped particles having a compact sheaf-like structure. Copper-containing α-alumina monohydrate particles of this size and form can be readily recovered from the oxidized liquor and recycled in the industrial process.

  13. Selective separation of copper over solder alloy from waste printed circuit boards leach solution.

    Science.gov (United States)

    Kavousi, Maryam; Sattari, Anahita; Alamdari, Eskandar Keshavarz; Firozi, Sadegh

    2017-02-01

    The printed circuit boards (PCBs) from electronic waste are important resource, since the PCBs contain precious metals such as gold, copper, tin, silver, platinum and so forth. In addition to the economic point of view, the presence of lead turns this scrap into dangerous to environment. This study was conducted as part of the development of a novel process for selective recovery of copper over tin and lead from printed circuit boards by HBF 4 leaching. In previous study, Copper with solder alloy was associated, simultaneously were leached in HBF 4 solution using hydrogen peroxide as an oxidant at room temperature. The objective of this study is the separation of copper from tin and lead from Fluoroborate media using CP-150 as an extractant. The influence of organic solvent's concentration, pH, temperature and A/O phase ratio was investigated. The possible extraction mechanism and the composition of the extracted species have been determined. The separation factors for these metals using this agent are reported, while efficient methods for separation of Cu (II) from other metal ions are proposed. The treatment of leach liquor for solvent extraction of copper with CP-150 revealed that 20% CP-150 in kerosene, a 30min period of contact time, and a pH of 3 were sufficient for the extraction of Cu(II) and 99.99% copper was recovered from the leached solution. Copyright © 2016. Published by Elsevier Ltd.

  14. An Approach to Microanalysis and Conservation of Silver - Copper Object in Agriculture Museum, Cairo, Egypt

    Directory of Open Access Journals (Sweden)

    prof.ABEER Gharib

    2013-01-01

    Full Text Available This research dealt examining, analysis and treatment of a silver - copper belt, it exhibited in Agriculture Museum in Cairo. This research aims to study the ancient silver alloy; because of the successful examination and analysis helps in the treatment of old metal objects and then maintain them. The analysis of archaeological objects requires simultaneously non-destructive (the objects are unique and precious, versatile (samples with different geometry, sensitive (trace elements are often important and multi-elemental methods. In this paper, scanning electron microscopy (SEM employed to diagnose the characteristic morphology and environmental effects of the silver-copper object. X- Ray diffraction (XRD used to identify the mineralogical composition of samples, inductively coupled plasma optical emission spectrometer (ICP used to determine the accurate elemental composition of the silver-copper object. The results obtained by this research showed that the alloy containing about 22% silver, 65% copper, and it covered with copper corrosion products, these results represent the correct diagnosis, which will help us to understand the fabrication of ancient silver-copper alloy, which is still needed more studies.

  15. Microstructure and properties of TP2 copper tube with La microalloying by horizontal continuous casting

    Directory of Open Access Journals (Sweden)

    Jin-hu Wu

    2018-01-01

    Full Text Available The TP2 copper tube was prepared with La microalloying by horizontal continuous casting (HCC. The absorptivity of La and its effects on microstructure, tensile and corrosion properties of HCC TP2 copper tube were studied by means of the inductively coupled plasma optical emission spectrometer (ICP-OES, optical microscope (OM, scanning electron microscope (SEM and potentiodynamic polarization measurements. The results show that the absorptivity of La in the HCC TP2 copper tube is about 15% under antivacuum conditions due to the good chemical activities of La. The impurity elements in copper tube such as O, S, Pb and Si can be significantly reduced, and the average columnar dendrite spacing of the copper tube can also be reduced from 2.21 mm to 0.93 mm by adding La. The ultimate tensile strength and the elongation with and without La addition are almost unchanged. However, the annual corrosion rate of the HCC TP2 copper tube is reduced from 10.18 mm•a-1 to 9.37 mm•a-1 by the purification effect of trace La.

  16. Polyethyleneimine anchored copper(II) complexes: synthesis, characterization, in vitro DNA binding studies and cytotoxicity studies.

    Science.gov (United States)

    Lakshmipraba, Jagadeesan; Arunachalam, Sankaralingam; Riyasdeen, Anvarbatcha; Dhivya, Rajakumar; Akbarsha, Mohammad Abdulkader

    2015-01-01

    The water soluble polyethyleneimine-copper(II) complexes, [Cu(phen)(L-tyr)BPEI]ClO4 (where phen=1,10-phenanthroline, L-tyr=L-tyrosine and BPEI=branched polyethyleneimine) with various degree of copper(II) complex units in the polymer chain were synthesized and characterized by elemental analysis and electronic, FT-IR, EPR spectroscopic techniques. The binding of these complexes with CT-DNA was studied using UV-visible absorption titration, thermal denaturation, emission, circular dichroism spectroscopy and cyclic voltammetric methods. The changes observed in the physicochemcial properties indicated that the binding between the polymer-copper complexes and DNA was mostly through electrostatic mode of binding. Among these complexes, the polymer-copper(II) complex with the highest degrees of copper(II) complex units (higher degrees of coordination) showed higher binding constant than those with lower copper(II) complex units (lower degrees of coordination) complexes. The complex with the highest number of metal centre bound strongly due to the cooperative binding effect. Therefore, anticancer study was carried out using this complex. The cytotoxic activity for this complex on MCF-7 breast cancer cell line was determined adopting MTT assay, acridine orange/ethidium bromide (AO/EB) staining and comet assay techniques, which revealed that the cells were committed to specific mode of cell death either apoptosis or necrosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Green synthesis of copper nanoparticles for the efficient removal (degradation) of dye from aqueous phase.

    Science.gov (United States)

    Sinha, Tanur; Ahmaruzzaman, M

    2015-12-01

    The present work reports the utilization of a common household waste material (fish scales of Labeo rohita) for the synthesis of copper nanoparticles. The method so developed was found to be green, environment-friendly, and economic. The fish scale extracts were acting as a stabilizing and reducing agents. This method avoids the use of external reducing and stabilizing agents, templates, and solvents. The compositional abundance of gelatin may be envisaged for the effective reductive as well as stabilizing potency. The mechanisms for the formation of nanoparticles have also been presented. The synthesized copper nanoparticles formed were predominantly spherical in nature with an average size of nanoparticles in the range of 25-37 nm. The copper nanoparticles showed characteristic Bragg's reflection planes of fcc which was supported by both selected area electron diffraction and X-ray diffraction pattern and showed surface plasmon resonance at 580 nm. Moreover, the energy dispersive spectroscopy pattern also revealed the presence of only elemental copper in the copper nanoparticles. The prepared nanoparticles were used for the remediation of a carcinogenic and noxious textile dye, Methylene blue, from aqueous solution. Approximately, 96 % degradation of Methylene blue dye was observed within 135 min using copper nanoparticles. The probable mechanism for the degradation of the dye has been presented, and the degraded intermediates have been identified using the liquid chromatography-mass spectroscopy technique. The high efficiency of nanoparticles as photocatalysts has opened a promising application for the removal of hazardous dye from industrial effluents contributing indirectly to environmental cleanup process.

  18. Use of ancient copper slags in Portland cement and alkali activated cement matrices.

    Science.gov (United States)

    Nazer, Amin; Payá, Jordi; Borrachero, María Victoria; Monzó, José

    2016-02-01

    Some Chilean copper slag dumps from the nineteenth century still remain, without a proposed use that encourages recycling and reduces environmental impact. In this paper, the copper slag abandoned in landfills is proposed as a new building material. The slags studied were taken from Playa Negra and Púquios dumps, both located in the region of Atacama in northern Chile. Pozzolanic activity in lime and Portland cement systems, as well as the alkali activation in pastes with copper slag cured at different temperatures, was studied. The reactivity of the slag was measured using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), electrical conductivity and pH in aqueous suspension and Fourier Transform Infrared Spectroscopy (FTIR). Furthermore, copper slag-Portland cement mortars with the substitution of 25% (by weight) of cement by copper slag and alkali-activated slag mortars cured at 20 and 65 °C were made, to determine the compressive strength. The results indicate that the ancient copper slags studied have interesting binding properties for the construction sector. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Aminealkylthiol and dithiol self-assembly as adhesion promoter between copper substrate and epoxy resin

    International Nuclear Information System (INIS)

    Denayer, J.; Delhalle, J.; Mekhalif, Z.

    2011-01-01

    To improve adhesion between copper and epoxy resin in printed circuit board, a roughness treatment of copper has been widely used. Nevertheless, new adhesion promoters have to be developed to face the miniaturization and sophistication of the electronic device. Self-assembled monolayers have met increasing interest in this field by using them as coupling agent between copper and the epoxy resin. This paper presents the deposition of an epoxy resin on copper modified by amine alkylthiol and dithiol monolayers and highlights the benefit brought by the monolayer in terms of adhesion. The chemical linkage between the amine SAMs and the epoxy function has been proved by the deposition on a short epoxy fragment, the 2-(4-fluorophenoxy-methyl)oxirane. The deposition of an epoxy resin mixed with amine curing agent has then been successfully achieved on amine terminated SAMs. The resulting polymer is homogeneous and well adherent on their surface, while the adhesion is lower on bare copper and not existing on methyl terminated SAMs. The formation of chemical bond Cu-S and N-epoxy is thus essential to increase the adhesion strength between copper and the polymer.

  20. Microstructure effects in CVD copper

    Science.gov (United States)

    Manger, Dirk Karl

    Computer chip manufacturers are beginning to implement copper as interconnect material in high-performance microprocessor metallization architectures. Replacing currently used aluminum metallization with its copper based counterpart will result in performance gain due to the low resistivity of copper (1.67muO·cm) which generates a reduction in (resistance x capacitance) signal delay. Futhermore, enhancements in stress and electromigration resistance by up to three orders of magnitude are expected from replacing aluminum with copper. Copper deposited by chemical vapor deposition has the proven ability to yield complete fill of aggressive via and trench structures at high deposition rates. At the same time, ultrathin Cu seed layers can be controlled grown by chemical vapor deposition (CVD) for use as activation layer in electrolytic plating (EP) applications. Additionally, integration studies using single and two-level damascene interconnect structures CVD Cu showed that excellent yield can be obtained. However, before CVD Cu can be incorporated into manufacturing process flows, several key reliability issues have to be addressed and resolved. At present, electroplating has the advantage of enhanced electromigration performance compared to CVD copper. It is therefore necessary to demonstrate the systematic ability to tailor the microstructure of CVD copper with the goal of enhanced electromigration and stress migration performance through the successful formation of (111) textured Cu with bamboo type microstructure. In the present work, the evolution of as-deposited Cu resistivity, grain size, texture, and surface roughness were systematically analyzed as a function of film thickness for an optimized CVD Cu process. In particular, investigations of the influence of substrate type and surface pretreatment on texture and grain size showed that: (a) Cu grows (111) textured on PVD TiN, if (002) Ti matrix is present, and on inorganic CVD TiN, regardless of the underlying

  1. Corrosion protection ability of self-assembled monolayer of 3-amino-5-mercapto-1,2,4-triazole on copper electrode

    Energy Technology Data Exchange (ETDEWEB)

    Rajkumar, Ganesan; Sethuraman, Mathur Gopalakrishnan, E-mail: mgsethu@rediffmail.com

    2014-07-01

    The self-assembled monolayer (SAM) of 3-amino-5-mercapto-1,2,4-triazole (AMTa) was formed on a copper surface and characterized using cyclic voltammetry, Fourier Transform Infra-red spectroscopy and scanning electron microscopy. Quantum chemical calculations suggested the stronger interaction between AMTa and copper. The protection ability of SAM has been evaluated using electrochemical impedance spectroscopy and potentiodynamic polarization measurements. The formed monolayer showed significant protection ability in 1% NaCl medium. The enhanced corrosion protection ability could be due to the compact film structure which blocks the electron transfer from the solution to AMTa monolayer modified copper substrate. - Highlights: • Self-assembled monolayer (SAM) of AMTa has been achieved on copper surface. • Monolayer formed has been duly characterized. • SAM of AMTa has been shown to offer significant protection to copper in NaCl medium.

  2. Copper welding; Les liaisons du cuivre

    Energy Technology Data Exchange (ETDEWEB)

    Monneau, Ph. [SDMS, 38 - Saint-Romans (France)

    2000-07-01

    The following categories of manufactured copper: Cu-c ( > 99.95% copper and less than 0.0003% phosphor) and Cu-OF (oxygen free copper) are useful in vacuum or ultra-vacuum techniques. Homogeneous binding (or heterogeneous with other metals) are mainly performed by welding (TIG, MIG, FE) or by brazing at high or low temperatures. In this article these different methods are reviewed with pros and cons, and several applications are presented, particularly the designing of high frequency resonator cavities for GANIL accelerator, these cavities were made out of solid copper. (A.C.)

  3. The copper-transporting ATPase pump and its potential role in copper-tolerance

    Science.gov (United States)

    Katie Ohno; C.A. Clausen; Frederick Green; G. Stanosz

    2016-01-01

    Copper-tolerant brown-rot decay fungi exploit intricate mechanisms to neutralize the efficacy of copper-containing preservative formulations. The production and accumulation oxalate is the most widely recognized theory regarding the mechanism of copper-tolerance in these fungi. The role of oxalate, however, may be only one part of a series of necessary components...

  4. A DFT study of hypercoordinated copper silicide nanotubes

    Science.gov (United States)

    Ai, Ling-Yan; Zhao, Hui-Yan; Wang, Jing; Liu, Ying

    2017-03-01

    The stability and electronic structures of copper silicide nanotubes (CuSiNTs) are calculated using first-principles density functional theory. Here these CuSiNTs of various different diameters, chiral vectors and morphologies were obtained by rolling up a novel two-dimensional hypercoordinated Cu2Si monolayer with high stability (Yang et al., J. Am. Chem. Soc. 137 (2015) 2757-2762). Electronic structure calculations showed that these CuSiNTs are conductors independent of their chiral vectors, diameters and morphologies. In addition, molecular dynamics (MD) simulations of the (6, 0) tube and the (8, 4) tube were performed. It was found that the (8, 4) tube has very good thermal stability and that its structure does not break down during MD simulations at initial temperatures up to 1500 K. Based on their electrical conductivity and good thermal stability, these CuSiNTs are promising candidates to envision application as metallic connections in nanoscale electronic devices.

  5. Charge and spin coupling in copper compounds with hemilabile noninnocent ligands – Ambivalence in three dimensions

    Czech Academy of Sciences Publication Activity Database

    Kaim, W.; Beyer, K.; Filippou, V.; Záliš, Stanislav

    2018-01-01

    Roč. 355, JAN 2018 (2018), s. 173-179 ISSN 0010-8545 R&D Projects: GA MŠk(CZ) LTC17052 Institutional support: RVO:61388955 Keywords : copper complexes * electronic structure * hemilabile ligands Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 13.324, year: 2016

  6. Iron(III) and copper(II) complexes of trans-bis(ferrocenyl)porphyrin

    Indian Academy of Sciences (India)

    Iron(III) and copper(II) complexes of trans-bis(ferrocenyl)porphyrin: Effect of metal ions on long-range electronic communication. Dipankar Sahoo Sankar Prasad Rath. Volume 127 Issue ... Keywords. Ferrocenylporphyrin; electrochemistry; spectro-electrochemistry; electrochemical conjugation; X-ray structure determination.

  7. Iron(III) and copper(II) complexes of trans-bis(ferrocenyl)porphyrin ...

    Indian Academy of Sciences (India)

    Iron(III) and copper(II) complexes of trans-bis(ferrocenyl)porphyrin: Effect of metal ions on long-range electronic communication. DIPANKAR SAHOO and SANKAR PRASAD RATH∗. Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India e-mail: sprath@iitk.ac.in. MS received 12 December ...

  8. Synthesis, characterization and behaviour to gamma radiation of the bis-L-alaninato-copper (II)

    International Nuclear Information System (INIS)

    Passos, B.F.T.

    1985-01-01

    The behaviour of coordinated compound obtained from the copper (II) and the L-(+)- alanine to gamma radiation was determined. A study of synthesis and characterization of this complex was made with elementary analysis, ultraviolet and visible electronic spectroscopy, infrared vibrational spectroscopy, proton magnetic resonance spectroscopy and thermo-gravimetric analysis. (C.G.C.)

  9. Compression strain-induced folding at intersecting deformation macrobands on the copper single crystals

    Science.gov (United States)

    Chumaevskii, A. V.; Lychagin, D. V.; Tarasov, S. Yu.

    2017-12-01

    Compression strain-induced surface pattern on copper single crystal faces was studied by means of optical, confocal laser and scanning electron microscopies. It was shown that apart from work-hardening effect of previously formed deformation macrobands there is a pure geometrical (size) effect which serves for changing the conditions for further deformation within the deformation macroband zones by folded structure formation.

  10. Charge and spin coupling in copper compounds with hemilabile noninnocent ligands – Ambivalence in three dimensions

    Czech Academy of Sciences Publication Activity Database

    Kaim, W.; Beyer, K.; Filippou, V.; Záliš, Stanislav

    2018-01-01

    Roč. 355, JAN 2018 (2018), s. 173-179 ISSN 0010-8545 R&D Projects: GA MŠk(CZ) LTC17052 Institutional support: RVO:61388955 Keywords : copper complexes * electronic structure * hemilabile ligands Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 13.324, year: 2016

  11. Investigation of the Hydroxylation Mechanism of Noncoupled Copper Oxygenases by Ab Initio Molecular Dynamics Simulations

    Czech Academy of Sciences Publication Activity Database

    Meliá, C.; Ferrer, S.; Řezáč, Jan; Parisel, O.; Reinaud, O.; Moliner, V.; de la Lande, A.

    2013-01-01

    Roč. 19, č. 51 (2013), s. 17328-17337 ISSN 0947-6539 Institutional support: RVO:61388963 Keywords : ab initio calculations * copper * electron transfer * enzymes * molecular dynamics * reaction mechanisms Subject RIV: CC - Organic Chemistry Impact factor: 5.696, year: 2013

  12. Severe plastic deformation of copper by machining: Microstructure refinement and nanostructure evolution with strain

    International Nuclear Information System (INIS)

    Swaminathan, S.; Brown, T.L.; Chandrasekar, S.; McNelley, T.R.; Compton, W.D.

    2007-01-01

    The microstructures of copper chips created by plane strain machining at ambient temperature have been analyzed using transmission electron microscopy (TEM) and orientation imaging microscopy (OIM). The strain imposed in the chips was varied by changing the tool rake angle. Characterization of orthogonal faces of the chips showed the microstructure to be essentially uniform through the chip volume, indicative also of uniform deformation

  13. Study of the propolis extract as a corrosion inhibitor of copper alloy ...

    African Journals Online (AJOL)

    These results were supplemented by IR Spectroscopy, Scanning electron microscopy (SEM) and EDX spectrum of chemical composition. The metal solution interface is simulated as a physical model by using Electrochemical Impedance Spectroscopy (EIS). Keywords: Copper Alloy, Propolis extract, ethylene glycol; ...

  14. Self-assembled 1-octadecyl-1H-benzimidazole film on copper ...

    Indian Academy of Sciences (India)

    Efficiency of the OBI film to protect copper from corrosion has been investigated in aq. HCl solution using electrochemical impedance spectroscopy, potentiodynamic polarization method, cyclic voltammetry, scanning electron microscopy and gravimetry. Results of these studies inferred that the OBI film has an inhibition ...

  15. A determination of the texture of a directionally solidified sample of high-purity copper

    DEFF Research Database (Denmark)

    Grant, Evan; Juul Jensen, Dorte; Ralph, Brian

    1986-01-01

    A study making a combined use of neutron diffraction and selected-area electron channelling to determine the solidification texture in a high-purity copper sample is described. Good correlation between the techniques is shown with both demonstrating a strong [100] fibre texture in the directionally...

  16. Effect of Copper on Passivity and Corrosion Behavior of Fe-xC-5Cu ...

    African Journals Online (AJOL)

    Effect of Copper on Passivity and Corrosion Behavior of Fe-xC-5Cu Alloy. ... Journal of Fundamental and Applied Sciences ... The metallurgical analyses, including, X-Ray diffraction (XRD), the scanning electron microscopy (SEM) with energy dispersive analysis (EDX), and induction hardening characterization are ...

  17. Atomic platinum layer coated titanium copper nitride supported on carbon nanotubes for the methanol oxidation reaction

    CSIR Research Space (South Africa)

    Zheng, Y

    2017-09-01

    Full Text Available . Later experiments data demonstrate that the activity and stability of the catalyst can be further enhanced via copper doping, which results from the modified electronic structure of the Pt atoms and the synergistic effects of the core-shell structure....

  18. Quantitative characterization of the orientation spread within individual grains in copper after tensile deformation

    DEFF Research Database (Denmark)

    Krog-Pedersen, Stine; Bowen, Jacob R.; Pantleon, Wolfgang

    2009-01-01

    By means of electron backscatter diffraction, orientations are determined on a regular grid on a polished section of a copper specimen after tensile deformation to 25%. Individual grains separated by boundaries with disorientation angles above 7° are identified and the microtexture in the form of...

  19. Fission neutron irradiation of copper containing implanted and transmutation produced helium

    DEFF Research Database (Denmark)

    Singh, B.N.; Horsewell, A.; Eldrup, Morten Mostgaard

    1992-01-01

    . The distributions of helium prior to fission neutron irradiation were determined by a combination of transmission electron microscopy (TEM) and positron annihilation techniques (PAT). These specimens, together with pure copper, were then irradiated with fission neutrons in a single capsule in fast flux test...

  20. Page 1 Nucleation and growth study of copper thin films 905 2.3 ...

    Indian Academy of Sciences (India)

    Scotch tape was attached to the film and then the tape was pulled out. SEM micrographs of the copper films were taken using Cambridge Instruments and JEOL microscope. The electron beam energy was 20kV and the magnification was 1k–10k. 3.