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Sample records for copper characterization fsw

  1. Inspection of copper canister for spent nuclear fuel by means of ultrasound. FSW monitoring with emission, copper characterization and ultrasonic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Tadeusz (ed.); Engholm, Marcus; Olofsson, Tomas (Uppsala Univ., Signals and Systems, Dept. of Technical Sciences, Uppsala (Sweden))

    2008-09-15

    This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in 2007. In the first part of the report we further develop the concept of monitoring of the friction stir welding (FSW) process by means of acoustic emission (AE) technique implemented using multiple sensors formed into a circular array. After a brief introduction into the field of arrays and beamforming we focus on the features of uniform circular arrays (UCA). Results obtained from the simulations of UCA beamformer based on phase mode concept are presented for the continuous wave as well as for the pulse, noise-free input signals. The influence of white noise corrupting the input pulse is also considered and a simple regularization technique proposed as a solution to this problem. The second part of the report is concerned with aspects related to ultrasonic attenuation of copper material used for canisters. We compare resonant ultrasound spectroscopy (RUS) with other methods used for characterization of the copper material. RUS is a non-destructive technique based on sensing mechanical resonances present in a tested sample in the ultrasonic frequency range. Resonance frequencies observed in a material sample (with given geometry) are directly related to the vibration modes occurring in the inspected volume defined by the material parameters (elastic constants). We solve the inverse problem that consists in using the information about resonance frequencies acquired in physical measurements for estimating material parameters. Our aim in this project is to investigate the feasibility of RUS for the grain size estimation in copper using copper specimens that were provided by SKB. In the final part we consider the design of input signals for ultrasonic arrays. The Bayesian linear minimum mean squared error (LMMSE) estimator discussed in our former reports is studied. We show that it

  2. Friction stir welding (FSW process of copper alloys

    Directory of Open Access Journals (Sweden)

    M. Miličić

    2016-01-01

    Full Text Available The present paper analyzes the structure of the weld joint of technically pure copper, which is realized using friction stir welding (FSW. The mechanism of thermo-mechanical processes of the FSW method has been identified and a correlation between the weld zone and its microstructure established. Parameters of the FSW welding technology influencing the zone of the seam material and the mechanical properties of the resulting joint were analyzed. The physical joining consists of intense mixing the base material along the joint line in the “doughy” phase. Substantial plastic deformations immediately beneath the frontal surface of tool provide fine-grained structure and a good quality joint. The optimum shape of the tool and the optimum welding regime (pressure force, rotation speed and the traverse speed of the tool in the heat affected zone enable the achievement of the same mechanical properties as those of the basic material, which justifies its use in welding reliable structures.

  3. Inspection of copper canister for spent nuclear fuel by means of ultrasound. Copper characterization, FSW monitoring with acoustic emission and ultrasonic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Tadeusz (ed.); Engholm, Marcus; Olofsson, Tomas (Uppsala Univ., Signals and Systems, Dept. of Technical Sciences, Uppsala (Sweden))

    2009-08-15

    This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in 2008. The first part of the report is concerned with aspects related to ultrasonic attenuation of copper material used for canisters. We present results of attenuation measurement performed for a number of samples taken from a real canister; two from the lid and four from different parts of canister wall. Ultrasonic attenuation of the material originating from canister lid is relatively low (less that 50 dB/m) and essentially frequency independent in the frequency range up to 5 MHz. However, for the material originating from the extruded canister part considerable variations of the attenuation are observed, which can reach even 200 dB/m at 3.5 MHz. In the second part of the report we present further development of the concept of the friction stir welding process monitoring by means of multiple sensors formed into a uniform circular array (UCA). After a brief introduction into modeling Lamb waves and UCA we focus on array processing techniques that enable estimating direction of arrival of multimodal Lamb waves. We consider two new techniques, the Capon beamformer and the broadband multiple signal classification technique (MUSIC). We present simulation results illustrating their performance. In the final part we present the phase shift migration algorithm for ultrasonic imaging of layered media using synthetic aperture concept. We start from explaining theory of the phase migration concept, which is followed by the results of experiments performed on copper blocks with drilled holes. We show that the proposed algorithm performs well for immersion inspection of metal objects and yields both improved spatial resolution and suppressed grain noise

  4. Inspection of copper canisters for spent nuclear fuel by means of ultrasound. Ultrasonic imaging, FSW monitoring with acoustic emission

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Tadeusz (ed.); Olofsson, Tomas; Wennerstroem, Erik [Uppsala Univ., Dept. of Technical Sciences (Sweden). Signals and Systems

    2006-12-15

    This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in years 2005/2006. In the first part of the report we propose a concept of monitoring of the friction stir welding (FSW) process by means of acoustic emission (AE) technique. First, we introduce the AE technique and then we present the principle of the system for monitoring the FSW process in cylindrical symmetry specific for the SKB canisters. We propose an omnidirectional circular array of ultrasonic transducers for receiving the AE signals generated by the FSW tool and the releases of the residual stress at canister's circumference. Finally, we review the theory of uniform circular arrays. The second part of the report is concerned with synthetic aperture focusing technique (SAFT) characterized by enhanced spatial resolution. We evaluate three different approaches to perform imaging with less computational cost than that of the extended SAFT (ESAFT) method proposed in our previous reports. First, a sparse version of ESAFT is presented, which solves the reconstruction problem only for a small set of the most probable scatterers in the image. A frequency domain the {omega}-k SAFT algorithm, which relies on the far-field approximation is presented in the second part. Finally, a detailed analysis of the most computationally intense step in the ESAFT and the sparse 2D deconvolution is presented. In the final part of the report we introduce basics of the 3D ultrasonic imaging that has a great potential in the inspection of the FSW welds. We discuss in some detail the three interrelated steps involved in the 3D ultrasonic imaging: data acquisition, 3D reconstruction, and 3D visualization.

  5. Analysis of microstructure and mechanical properties of aluminium-copper joints welded by FSW process

    Science.gov (United States)

    Iordache, M.; Sicoe, G.; Iacomi, D.; Niţu, E.; Ducu, C.

    2017-08-01

    The research conducted in this article aimed to check the quality of joining some dissimilar materials Al-Cu by determining the mechanical properties and microstructure analysis. For the experimental measurements there were used tin alloy Al - EN-AW-1050A with a thickness of 2 mm and Cu99 sheet with a thickness of 2 mm, joined by FSW weld overlay. The main welding parameters were: rotating speed of the rotating element 1400 rev/min, speed of the rotating element 50 mm/min. The experimental results were determined on samples specially prepared for metallographic analysis. In order to prepare samples for their characterization, there was designed and built a device that allowed simultaneous positioning and fixing for grinding. The characteristics analyzed in the joint welded samples were mictrostructure, microhardness and residual stresses. The techniques used to determine these characteristics were optical microscopy, electron microscopy with fluorescence radioactive elemental analysis (EDS), Vickers microhardness line - HV0.3 and X-ray diffractometry.

  6. State of the art of the welding method for sealing spent nuclear fuel canister made of copper. Part 1 - FSW

    Energy Technology Data Exchange (ETDEWEB)

    Purhonen, T.

    2014-05-15

    The purpose of this report is to gather together comprehensive information concerning FSW as an optional welding method for welding the nuclear waste copper canister at the disposal facility. This report discusses the current situation, knowledge of the process and information concerning results of the development and research work related to welding thick copper and the special needs of the disposal environment. Most of the research work and development work has been done by Posiva's Swedish partner SKB, Swedish Nuclear Fuel and Waste Management Co. SKB chose FSW as their reference welding method in 2005. FSW (friction stir welding) is a solid-state welding method, invented in 1991, in which frictional heat is generated between the tool and the weld metal, causing the metal to soften, normally without reaching the melting point, and allowing the tool to traverse the joint line. Friction stir welding can be used for joining many types of materials and material combinations, if the tool materials and designs can be found which operate at the forging temperature of the workpiece. The general requirements for the copper canister weld and base material are presented in Posiva's VAHA-system, which sets the most critical values or demands concerning the short- and long-term properties or other needs. The sections in this report are set out in a similar way as in the VAHA-system. Concerning the results from the research and development work, it can be said that FS weld material fulfils the values set by VAHA. The quality of the welds fulfils the set demands for intact weld material and the welding process is robust using an automatic control system. There still remains work concerning the acceptance procedure for the welding process and other open issues which are described in this report. (orig.)

  7. Investigation into Interface Lifting Within FSW Lap Welds

    Energy Technology Data Exchange (ETDEWEB)

    K. S. Miller; C. R. Tolle; D. E. Clark; C. I. Nichol; T. R. McJunkin; H. B. Smartt

    2008-06-01

    Friction stir welding (FSW) is rapidly penetrating the welding market in many materials and applications, particularly in aluminum alloys for transportation applications. As this expansion outside the research laboratory continues, fitness for service issues will arise, and process control and NDE methods will become important determinants of continued growth. The present paper describes research into FSW weld nugget flaw detection within aluminum alloy lap welds. We present results for two types of FSW tool designs: a smooth pin tool and a threaded pin tool. We show that under certain process parameters (as monitored during welding with a rotating dynamometer that measures x, y, z, and torque forces) and tooling designs, FSW lap welds allow significant nonbonded interface lifting of the lap joint, while forming a metallurgical bond only within the pin region of the weld nugget. These lifted joints are often held very tightly together even though unbonded, and might be expected to pass cursory NDE while representing a substantial compromise in joint mechanical properties. The phenomenon is investigated here via radiographic and ultrasonic NDE techniques, with a copper foil marking insert (as described elsewhere) and by the tensile testing of joints. As one would expect, these results show that tool design and process parameters significantly affect plactic flow and this lifted interface. NDE and mechanical strength ramifications of this defect are discussed.

  8. Interfacial microstructure and properties of copper clad steel produced using friction stir welding versus gas metal arc welding

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Z.; Chen, Y. [Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo (Canada); Haghshenas, M., E-mail: mhaghshe@uwaterloo.ca [Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo (Canada); Nguyen, T. [Mechanical Systems Engineering, Conestoga College, Kitchener (Canada); Galloway, J. [Welding Engineering Technology, Conestoga College, Kitchener (Canada); Gerlich, A.P. [Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo (Canada)

    2015-06-15

    A preliminary study compares the feasibility and microstructures of pure copper claddings produced on a pressure vessel A516 Gr. 70 steel plate, using friction stir welding versus gas metal arc welding. A combination of optical and scanning electron microscopy is used to characterize the grain structures in both the copper cladding and heat affected zone in the steel near the fusion line. The friction stir welding technique produces copper cladding with a grain size of around 25 μm, and no evidence of liquid copper penetration into the steel. The gas metal arc welding of copper cladding exhibits grain sizes over 1 mm, and with surface microcracks as well as penetration of liquid copper up to 50 μm into the steel substrate. Transmission electron microscopy reveals that metallurgical bonding is produced in both processes. Increased diffusion of Mn and Si into the copper cladding occurs when using gas metal arc welding, although some nano-pores were detected in the FSW joint interface. - Highlights: • Cladding of steel with pure copper is possible using either FSW or GMAW. • The FSW yielded a finer grain structure in the copper, with no evidence of cracking. • The FSW joint contains some evidence of nano-pores at the interface of the steel/copper. • Copper cladding by GMAW contained surface cracks attributed to high thermal stresses. • The steel adjacent to the fusion line maintained a hardness value below 248 HV.

  9. Material characterization of ancient Indian copper

    Indian Academy of Sciences (India)

    A Srivastava; R Balasubramaniam

    2003-10-01

    A chalcolithic (2350–1800 BC) copper chisel from Balathal has been characterized by X-ray diffraction, microstructural and electrochemical methods. The surface patina was composed of sulfates and oxysulfates in the outer layers while the inner layers were rich in copper oxides. The chisel exhibited smaller grain sizes near two of the surfaces while the structure in the interior was equiaxed. The deformed grains and inclusions near the surfaces and variation in the microhardness of the sample from different faces proved that the copper chisel was processed by cold deformation after initial casting of the square cross-section chisel. The electrochemical behaviour of chalcolithic Cu has been compared with that of a modern Cu sample by potentiodynamic polarization studies. The corrosion rate of chalcolithic Cu in aerated 3.5% NaCl solution was only marginally higher than that of modern Cu. The higher rate of corrosion has been attributed to the presence of second phase sulfide inclusions. The excellent condition of preservation of the 3800-year-old copper object, with no indications of stress corrosion cracking, suggests that pure copper or copper-based materials can be seriously considered as candidate canister materials for long-term underground storage of nuclear wastes in underground repositories.

  10. An Introduction to Flight Software Development: FSW Today, FSW 2010

    Science.gov (United States)

    Gouvela, John

    2004-01-01

    Experience and knowledge gained from ongoing maintenance of Space Shuttle Flight Software and new development projects including Cockpit Avionics Upgrade are applied to projected needs of the National Space Exploration Vision through Spiral 2. Lessons learned from these current activities are applied to create a sustainable, reliable model for development of critical software to support Project Constellation. This presentation introduces the technologies, methodologies, and infrastructure needed to produce and sustain high quality software. It will propose what is needed to support a Vision for Space Exploration that places demands on the innovation and productivity needed to support future space exploration. The technologies in use today within FSW development include tools that provide requirements tracking, integrated change management, modeling and simulation software. Specific challenges that have been met include the introduction and integration of Commercial Off the Shelf (COTS) Real Time Operating System for critical functions. Though technology prediction has proved to be imprecise, Project Constellation requirements will need continued integration of new technology with evolving methodologies and changing project infrastructure. Targets for continued technology investment are integrated health monitoring and management, self healing software, standard payload interfaces, autonomous operation, and improvements in training. Emulation of the target hardware will also allow significant streamlining of development and testing. The methodologies in use today for FSW development are object oriented UML design, iterative development using independent components, as well as rapid prototyping . In addition, Lean Six Sigma and CMMI play a critical role in the quality and efficiency of the workforce processes. Over the next six years, we expect these methodologies to merge with other improvements into a consolidated office culture with all processes being guided by

  11. An Introduction to Flight Software Development: FSW Today, FSW 2010

    Science.gov (United States)

    Gouvela, John

    2004-01-01

    Experience and knowledge gained from ongoing maintenance of Space Shuttle Flight Software and new development projects including Cockpit Avionics Upgrade are applied to projected needs of the National Space Exploration Vision through Spiral 2. Lessons learned from these current activities are applied to create a sustainable, reliable model for development of critical software to support Project Constellation. This presentation introduces the technologies, methodologies, and infrastructure needed to produce and sustain high quality software. It will propose what is needed to support a Vision for Space Exploration that places demands on the innovation and productivity needed to support future space exploration. The technologies in use today within FSW development include tools that provide requirements tracking, integrated change management, modeling and simulation software. Specific challenges that have been met include the introduction and integration of Commercial Off the Shelf (COTS) Real Time Operating System for critical functions. Though technology prediction has proved to be imprecise, Project Constellation requirements will need continued integration of new technology with evolving methodologies and changing project infrastructure. Targets for continued technology investment are integrated health monitoring and management, self healing software, standard payload interfaces, autonomous operation, and improvements in training. Emulation of the target hardware will also allow significant streamlining of development and testing. The methodologies in use today for FSW development are object oriented UML design, iterative development using independent components, as well as rapid prototyping . In addition, Lean Six Sigma and CMMI play a critical role in the quality and efficiency of the workforce processes. Over the next six years, we expect these methodologies to merge with other improvements into a consolidated office culture with all processes being guided by

  12. On the computational modeling of FSW processes

    OpenAIRE

    Agelet de Saracibar Bosch, Carlos; Chiumenti, Michèle; Santiago, Diego de; Cervera Ruiz, Miguel; Dialami, Narges; Lombera, Guillermo

    2010-01-01

    This work deals with the computational modeling and numerical simulation of Friction Stir Welding (FSW) processes. Here a quasi-static, transient, mixed stabilized Eulerian formulation is used. Norton-Hoff and Sheppard-Wright rigid thermoplastic material models have been considered. A product formula algorithm, leading to a staggered solution scheme, has been used. The model has been implemented into the in-house developed FE code COMET. Results obtained in the simulation of FSW process are c...

  13. Fabrication and Characterization of Metallic Copper and Copper Oxide Nanoflowers

    Directory of Open Access Journals (Sweden)

    *H. S. Virk

    2011-12-01

    Full Text Available Copper nanoflowers have been fabricated using two different techniques; electro-deposition of copper in polymer and anodic alumina templates, and cytyltrimethal ammonium bromide (CTAB-assisted hydrothermal method. Scanning Electron Microscope (SEM images record some interesting morphologies of metallic copper nanoflowers. Field Emission Scanning Electron Microscope (FESEM has been used to determine morphology and composition of copper oxide nanoflowers. X-ray diffraction (XRD pattern reveals the monoclinic phase of CuO in the crystallographic structure of copper oxide nanoflowers. There is an element of random artistic design of nature, rather than science, in exotic patterns of nanoflowers fabricated in our laboratory.

  14. Microstructural Characterization of Internal Welding Defects and Their Effect on the Tensile Behavior of FSW Joints of AA2198 Al-Cu-Li Alloy

    Science.gov (United States)

    Le Jolu, Thomas; Morgeneyer, Thilo F.; Denquin, Anne; Sennour, Mohamed; Laurent, Anne; Besson, Jacques; Gourgues-Lorenzon, Anne-Françoise

    2014-11-01

    Internal features and defects such as joint line remnant, kissing bond, and those induced by an initial gap between the two parent sheets were investigated in AA2198-T851 friction stir welded joints. They were compared with the parent material and to defect-free welds obtained using a seamless sheet. The cross-weld tensile strength was reduced by the defects by less than 6 pct. The fracture elongation was not significantly affected in view of experimental scatter. Fracture location, however, changed from the thermomechanically affected zone (retreating side) to the defect in the weld nugget for the welds bearing a kissing bond and for some of the gap welds. The kissing bond was shown by EBSD to be an intergranular feature; it fractured under a normal engineering stress close to 260 MPa during an in situ SEM tensile test. Synchrotron tomography after interrupted tensile testing confirmed opening of the kissing bond. For an initial gap of 23 pct of the sheet thickness, intergranular fracture of copper-enriched or oxide-bearing grain boundaries close to the nugget root was evidenced. The stress and strain state of cross-weld specimens loaded under uniaxial tension was assessed using a 3D finite element, multi-material model, determined on the basis of experimental data obtained on the same specimens using digital image correlation.

  15. Friction stir welding of copper alloys

    Institute of Scientific and Technical Information of China (English)

    Liu Shuhua; Liu Meng; Wang Deqing; Xu Zhenyue

    2007-01-01

    Copper plates,brass plates and copper/brass plates were friction stir welded with various parameters. Experimental results show that the microstructure of the weld is characterized by its much finer grains as contrasted with the coarse grains of parent materials and the heat-affected zones are very narrow. The microhardness of the copper weld is a little higher than that of parent plate. The microhardness of brass weld is about 25% higher than that of parent material. The tensile strength of copper joints increases with increasing welding speed in the test range. The range of parameters to obtain good welds for copper is much wider than that for brass. When different materials were welded, the position of copper plate before welding affected the quality of FSW joints. If the copper plate was put on the advancing side of weld, the good quality of weld could be got under proper parameters.

  16. Isolation and characterization of bacteria resistant to metallic copper surfaces.

    Science.gov (United States)

    Santo, Christophe Espírito; Morais, Paula Vasconcelos; Grass, Gregor

    2010-03-01

    Metallic copper alloys have recently attracted attention as a new antimicrobial weapon for areas where surface hygiene is paramount. Currently it is not understood on a molecular level how metallic copper kills microbes, but previous studies have demonstrated that a wide variety of bacteria, including Escherichia coli, Staphylococcus aureus, and Clostridium difficile, are inactivated within minutes or a few hours of exposure. In this study, we show that bacteria isolated from copper alloy coins comprise strains that are especially resistant against the toxic properties exerted by dry metallic copper surfaces. The most resistant of 294 isolates were Gram-positive staphylococci and micrococci, Kocuria palustris, and Brachybacterium conglomeratum but also included the proteobacterial species Sphingomonas panni and Pseudomonas oleovorans. Cells of some of these bacterial strains survived on copper surfaces for 48 h or more. Remarkably, when these dry-surface-resistant strains were exposed to moist copper surfaces, resistance levels were close to those of control strains and MICs for copper ions were at or below control strain levels. This suggests that mechanisms conferring resistance against dry metallic copper surfaces in these newly isolated bacterial strains are different from well-characterized copper ion detoxification systems. Furthermore, staphylococci on coins did not exhibit increased levels of resistance to antibiotics, arguing against coselection with copper surface resistance traits.

  17. Electrical Characterization of Spherical Copper Oxide Memristive Array Sensors

    Science.gov (United States)

    2014-03-27

    running, dinner-table debate etiquette, sailing, electric guitar, and the Seattle bus system, but only earned his Bachelor of Science in Electrical ... ELECTRICAL CHARACTERIZATION OF SPHERICAL COPPER OXIDE MEMRISTIVE ARRAY SENSORS THESIS James P. Orta, Second Lieutenant, USAF AFIT-ENP-14-M-40...not subject to copyright protection in the United States. AFIT-ENP-14-M-40 ELECTRICAL CHARACTERIZATION OF SPHERICAL COPPER OXIDE MEMRISTIVE ARRAY

  18. Copper homeostasis in grapevine: functional characterization of the Vitis vinifera copper transporter 1.

    Science.gov (United States)

    Martins, Viviana; Bassil, Elias; Hanana, Mohsen; Blumwald, Eduardo; Gerós, Hernâni

    2014-07-01

    The Vitis vinifera copper transporter 1 is capable of self-interaction and mediates intracellular copper transport. An understanding of copper homeostasis in grapevine (Vitis vinifera L.) is particularly relevant to viticulture in which copper-based fungicides are intensively used. In the present study, the Vitis vinifera copper transporter 1 (VvCTr1), belonging to the Ctr family of copper transporters, was cloned and functionally characterized. Amino acid sequence analysis showed that VvCTr1 monomers are small peptides composed of 148 amino acids with 3 transmembrane domains and several amino acid residues typical of Ctr transporters. Bimolecular fluorescence complementation (BiFC) demonstrated that Ctr monomers are self-interacting and subcellular localization studies revealed that VvCTr1 is mobilized via the trans-Golgi network, through the pre-vacuolar compartment and located to the vacuolar membrane. The heterologous expression of VvCTr1 in a yeast strain lacking all Ctr transporters fully rescued the phenotype, while a deficient complementation was observed in a strain lacking only plasma membrane-bound Ctrs. Given the common subcellular localization of VvCTr1 and AtCOPT5 and the highest amino acid sequence similarity in comparison to the remaining AtCOPT proteins, Arabidopsis copt5 plants were stably transformed with VvCTr1. The impairment in root growth observed in copt5 seedlings in copper-deficient conditions was fully rescued by VvCTr1, further supporting its involvement in intracellular copper transport. Expression studies in V. vinifera showed that VvCTr1 is mostly expressed in the root system, but transcripts were also present in leaves and stems. The functional characterization of VvCTr-mediated copper transport provides the first step towards understanding the physiological and molecular responses of grapevines to copper-based fungicides.

  19. Electrochemical Synthesis and Structural Characterization of a Novel Mixed-valence Copper (I)-copper (II) Complex: {[Bis(ethylenediamine) Copper (II)] Bis[diiodocuprate (I)]}

    OpenAIRE

    Mahboobeh Dashti Ardakani; Majid M. Heravi; Saeed Dehghanpour; Lida Fotouhi

    2007-01-01

    A novel, mixed-valent copper(I)-copper(II) complex, {[bis(ethylene-diamine)copper(II)] bis[diiodocuprate(I)]} (1), has been prepared by electrochemicaldissolution of a sacrificial copper anode in a solution of ethylenediamine (en), I2 andtetraethylammoniumperchlorate (TEAP) as supporting electrolyte in acetonitrile (AcN)and characterized by single-crystal X-ray structure determination. The crystal structure ofthe complex 1 shows that it consists of a CuI2 polymer formed from I- ligands bridgi...

  20. 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

  1. Preparation and characterization of copper-doped cobalt oxide electrodes.

    Science.gov (United States)

    Rosa-Toro, A La; Berenguer, R; Quijada, C; Montilla, F; Morallón, E; Vazquez, J L

    2006-11-30

    Cobalt oxide (Co3O4) and copper-doped cobalt oxide (CuxCo(3-x)O4) films have been prepared onto titanium support by the thermal decomposition method. The electrodes have been characterized by different techniques such as cyclic voltammetry, scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy (XPS). The effect on the electrochemical and crystallographic properties and surface morphology of the amount of copper in the oxide layer has been analyzed. The XPS spectra correspond to a characteristic monophasic Cu-Co spinel oxides when x is below 1. However, when the copper content exceeds that for the stoichiometric CuCo2O4 spinel, a new CuO phase segregates at the surface. The analysis of the surface cation distribution indicates that Cu(II) has preference for octahedral sites.

  2. Mechanical Properties and Microstructure of TIG and FSW Joints of a New Al-Mg-Mn-Sc-Zr Alloy

    Science.gov (United States)

    Xu, Guofu; Qian, Jian; Xiao, Dan; Deng, Ying; Lu, Liying; Yin, Zhimin

    2016-04-01

    A new Al-5.8%Mg-0.4%Mn-0.25%Sc-0.10%Zr (wt.%) alloy was successfully welded by tungsten inert gas (TIG) and friction stir welding (FSW) techniques, respectively. The mechanical properties and microstructure of the welded joints were investigated by microhardness measurements, tensile tests, and microscopy methods. The results show that the ultimate tensile strength, yield strength, and elongation to failure are 358, 234 MPa, and 27.6% for TIG welded joint, and 376, 245 MPa and 31.9% for FSW joint, respectively, showing high strength and superior ductility. The TIG welded joint fails in the heat-affected zone and the fracture of FSW joint is located in stirred zone. Al-Mg-Mn-Sc-Zr alloy is characterized by lots of dislocation tangles and secondary coherent Al3(Sc,Zr) particles. The superior mechanical properties of the TIG and FSW joints are mainly derived from the Orowan strengthening and grain boundary strengthening caused by secondary coherent Al3(Sc,Zr) nano-particles (20-40 nm). For new Al-Mg-Mn-Sc-Zr alloy, the positive effect from secondary Al3(Sc, Zr) particles in the base metal can be better preserved in FSW joint than in TIG welded joint.

  3. Formation and characterization of infrared absorbing copper oxide surfaces

    Science.gov (United States)

    Arslan, Burcu; Demirci, Gökhan; Erdoğan, Metehan; Karakaya, İshak

    2017-04-01

    Copper oxide formation has been investigated to combine the advantages of producing different size and shapes of coatings that possess good light absorbing properties. An aqueous blackening solution was investigated and optimum composition was found as 2.5 M NaOH and 0.225 M NaClO to form velvet copper oxide films. A two-step oxidation mechanism was proposed for the blackening process by carefully examining the experimental results. Formation of Cu2O was observed until the entire copper surface was covered at first. In the second step, Cu2O surface was further oxidized to CuO until the whole Cu2O surface was covered by CuO. Therefore, blackened copper surfaces consisted of Cu2O/CuO duplex oxides. Characterization of the coatings were performed in terms of microstructure, phase analysis, chemical state, infrared specular and total reflectivity by SEM, XRD, XPS, FTIR and UV-vis spectrophotometry, respectively.

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

    Directory of Open Access Journals (Sweden)

    Usman MS

    2013-11-01

    Full Text Available Muhammad Sani Usman,1 Mohamed Ezzat El Zowalaty,2,5 Kamyar Shameli,1,3 Norhazlin Zainuddin,1 Mohamed Salama,4 Nor Azowa Ibrahim1 1Department of Chemistry, Faculty of Science, 2Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, Universiti Putra Malaysia, Selangor, Malaysia; 3Materials and Energy, Research Center, Karaj, Iran; 4Faculty of Pharmacy, UiTM, Puncak Alam, Selangor, Malaysia; 5Department of Environmental Health, Faculty of Public Health and Tropical Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia Abstract: 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. Keywords: chitosan, copper nanoparticles, antimicrobial activity, chemical synthesis, aqueous medium

  5. Synthesis and characterization of Copper/Cobalt/Copper/Iron nanostructurated films with magnetoresistive properties

    Science.gov (United States)

    Ciupinǎ, Victor; Prioteasa, Iulian; Ilie, Daniela; Manu, Radu; Petrǎşescu, Lucian; Tutun, Ştefan Gabriel; Dincǎ, Paul; MustaÅ£ǎ, Ion; Lungu, Cristian Petricǎ; Jepu, IonuÅ£; Vasile, Eugeniu; Nicolescu, Virginia; Vladoiu, Rodica

    2017-02-01

    Copper/Cobalt/Copper/Iron thin films were synthesized in order to obtain nanostructured materials with special magnetoresistive properties. The multilayer films were deposited on silicon substrates. In this respect we used Thermionic Vacuum Arc Discharge Method (TVA). The benefit of this deposition technique is the ability to have a controlled range of thicknesses starting from few nanometers to hundreds of nanometers. The purity of the thin films was insured by a high vacuum pressure and a lack of any kind of buffer gas inside the coating chamber. The morphology and structure of the thin films were analyzed using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) Techniques and Energy Dispersive X-ray Spectroscopy (EDXS). Magnetoresistive measurement results depict that thin films possess Giant Magneto-Resistance Effect (GMR). Magneto-Optic-Kerr Effect (MOKE) studies were performed to characterize the magnetic properties of these thin films.

  6. Rheological Phase Synthesis and Characterization of Copper Monosalicylate

    Institute of Scientific and Technical Information of China (English)

    YangYi-yong; LiLiang-chao; YuanLiang-jie; SunJu-tang; ZhangKe-li

    2003-01-01

    A new structural copper (Ⅱ) monosalicylate,Cu(OC6H4CO2 )·H2O, was synthesized by the rheological phase reaction method from salicylic acid and copper oxide in 1 : 1 mole ratio. The structure was characterized by powder X-ray diffraction, IR and thermogravimetry. The Cu (OC6H4CO2 )·H2O belongs to monoclinic system, with cell dimension:a=2. 136 28(67), b=0. 657 84(22), c=1. 594 09(50)nm,β=108. 434(25) , V=2. 125 28(83) nm3, Z=12, Dcalc=2.041 kg·L-1 Dobs=2.003 kg·L-1. The crystal water was lost at 96-250℃. The determined magnetic moment and magnetic susceptibility were 1. 947 B. M. and 6. 546×10-6(287.20 K), respectively.

  7. Rheological Phase Synthesis and Characterization of Copper Monosalicylate

    Institute of Scientific and Technical Information of China (English)

    Yang Yi-yong; Li Liang-chao; Yuan Liang-jie; Sun Ju-tang; Zhang Ke-li

    2003-01-01

    A new structural copper (Ⅱ) monosalicylate,Cu(OC6 H4 CO2 ) @ H2 O, was synthesized by the rheological phase reaction method from salicylic acid and copper oxide in 1 : 1 mole ratio. The structure was characterized by powder X-ray diffraction, IR and thermogravimetry. The Cu (OC6 H4 CO2 )@ H2O belongs to monoclinic system, with cell dimen-sion: a=2. 136 28(67), b=0. 657 84(22), c=1. 594 09(50)nm, β=108. 434(25) , V=2. 125 28(83) nm3, Z=12, Dcalc=2. 041 kg@L-1 , Dobs = 2. 003 kg@L-1. The crystal water was lost at 96-250°C. The determined magnetic moment and magnetic susceptibility were 1. 947 B. M. and 6. 546 × 10-6 (287.20 K), respectively.

  8. Preparation and characterization of microgels sensitive toward copper II ions.

    Science.gov (United States)

    Muratalin, Marat; Luckham, Paul F

    2013-04-15

    An emulsion polymerization technique has been used to prepare chemically crosslinked microgels in aqueous suspension that are sensitive to the presence of copper ions. Poly(N-isopropylacrylamide) (PNIPAM) was copolymerized with different amounts of 1-vinylimidazole (VI), and the resultant microgels exhibited multi-responsive behavior being sensitive to changes in temperature, pH and to the presence of metal ions, particularly copper. These swelling properties of the microgel particles were characterized using dynamic light scattering (DLS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effect of temperature showed that the microgel particles shrunk continuously as the temperature was raised, up to a temperature of 50°C, and the volume phase transition temperature, VPTT, has been shifted to higher temperatures (in the range of 35-45°C) compared to pure PNIPAM microgels where the VPTT≈30-35°C. The particle size of these microgels was also investigated as a function of pH; the microgel particles became swollen at low pH and collapsed at high pH, due to the ionization of the VI component of the microgels. Most interesting, however, was the effect of the copper ion concentration in solution. The PNIPAM-co-VI microgels were found to swell with increasing concentration of Cu(2+) up to 0.3g/l of Cu(2+) due to adsorption of the cations inside the particle, which leads to charging up the internal phase of the microgel. However, at higher concentrations of added copper (II) ions, the binding forces of complexation lead to conformational changes to the microgel resulting in weaker polymer-solvent interaction and consequential shrinkage again of the polymer. In addition, the copper (II) uptake was calculated, and the uptake was found to be well described by the Langmuir adsorption isotherm, with up to 2g of copper II being taken up by 1g of microgel. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Characterization of chilean copper slag smelting nineteenth century

    Directory of Open Access Journals (Sweden)

    Amin Nazer

    2016-12-01

    Full Text Available The aim of this work is to characterize four copper smelters slag nineteenth century, from abandoned landfills in Atacama Region - Chile, using the techniques of X-ray fluorescence (XRF, X-ray diffraction (XRD, scanning electron microscopy (SEM, particle analysis by laser diffraction (ADL, Fourier Transform Infrared Spectroscopy (FTIR and thermogravimetric analysis (TGA. Copper slags studied were chemically classified as acidic slags, this slags presented higher SiO2 content (38–49% than Fe2O3 (18–37% and a significant amount of CaO (8–26% and Al2O3 (8.5%. Mineralogy and structure was varied, presenting one of them an amorphous structure and the remaining three, a crystalline structure with partially amorphous character. The majority mineral phases presented in the copper slag were diopside, fayalite, magnetite, cristobalite and clinoferrosilita. Calcium levels indicate that the slags could have cementitious properties for use as a binder in construction materials. Moreover, the significant amount of slag available and CuO content (0.6–1.2% show that may be of interest as raw material for metal recovery.

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

    Science.gov (United States)

    Reznickova, A.; Orendac, M.; Kolska, Z.; Cizmar, E.; Dendisova, M.; Svorcik, V.

    2016-12-01

    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.

  11. Material Flow Modification in a FSW Through Introduction of Flats

    Science.gov (United States)

    Schneider, Judy; Brooke, Shane; Nunes, Arthur C.

    2016-02-01

    Friction stir welding (FSW) is a solid-state process in which a non-consumable weld tool is used to stir metal together to obtain a fully consolidated weld seam. There is controversy regarding the contributions of various attributes of the pin design, especially with regards to flats and flutes. In this study, similar FSWs made with threaded cylindrical pin-tools having 0, 1, 2, 3, 4, and 5 flats were compared. Slight increases in torque were noted with increasing flats. Significant changes in the FSW structure with varying numbers of flats were observed, but without significant changes in tensile strength. Changes in the textural banding shape, the addition of sub-bands, and a new set of bands from coalescence of band kinks constitute the structural changes observed. Explanations of these structural changes in terms of tool interactions with the FSW metal are offered.

  12. A computational model for the numerical simulation of FSW processes

    OpenAIRE

    Agelet de Saracibar Bosch, Carlos; Chiumenti, Michèle; Santiago, Diego de; Cervera Ruiz, Miguel; Dialami, Narges; Lombera, Guillermo

    2010-01-01

    In this paper a computational model for the numerical simulation of Friction Stir Welding (FSW) processes is presented. FSW is a new method of welding in solid state in which a shouldered tool with a profile probe is rotated and slowly plunged into the joint line between two pieces of sheet or plate material which are butted together. Once the probe has been completely inserted, it is moved with a small tilt angle in the welding direction. Here a quasi-static, thermal transient, mixed mult...

  13. Growth and characterization of diammonium copper disulphate hexahydrate single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Siva Sankari, R. [Department of Physics, Agni College of Technology, Thalambur, Chennai 603103 (India); Perumal, Rajesh Narayana, E-mail: r.shankarisai@gmail.com [Department of Physics, SSN College of Engineering, Kalavakkam, Chennai 603110 (India)

    2014-03-01

    Graphical abstract: Diammonium copper disulphate hexahydrate (DACS) is one of the most promising inorganic dielectric crystals with exceptional mechanical properties. Good quality crystals of DACS were grown by using solution method in a period of 30 days. The grown crystals were subjected to single crystal X-ray diffraction analysis in order to establish their crystalline nature. Thermo gravimetric, differential thermal analysis, FTIR, and UV–vis–NIR analysis were performed for the crystal. Several solid state physical parameters have been determined for the grown crystals. The dielectric constant and the dielectric loss and AC conductivity of the grown crystal were studied as a function of frequency and temperature has been calculated and plotted. - Highlights: • Diammonium copper disulphate is grown for the first time and CCDC number obtained. • Thermal analysis is done to see the stability range of the crystals. • Band gap and UV cut off wavelength of the crystal are determined to be 2.4 eV and 472.86 nm, respectively. • Dielectric constant, dielectric loss and AC conductivity are plotted as a function of applied field. - Abstract: Diammonium copper disulphate hexahydrate is one of the most promising inorganic crystals with exceptional dielectric properties. A good quality crystal was harvested in a 30-day period using solution growth method. The grown crystal was subjected to various characterization techniques like single crystal X-ray diffraction analysis, thermo gravimetric, differential thermal analysis, FTIR, and UV–vis–NIR analysis. Unit cell dimensions of the grown crystal have been identified from XRD studies. Functional groups of the title compounds have been identified from FTIR studies. Thermal stability of the samples was checked by TG/DTA studies. Band gap of the crystal was calculated. The dielectric constant and dielectric loss were studied as a function of frequency of the applied field. AC conductivity was plotted as a function

  14. Synthesis and spectroscopic characterization of copper zinc aluminum nanoferrite particles

    Science.gov (United States)

    Lakshmi Reddy, S.; Ravindra Reddy, T.; Roy, Nivya; Philip, Reji; Montero, Ovidio Almanza; Endo, Tamio; Frost, Ray L.

    2014-06-01

    Copper doped zinc aluminum ferrites CuxZn1-x.(AlxFe2-x)O4 are synthesized by the solid-state reaction route and characterized by XRD, TEM, EPR and non linear optical spectroscopy techniques. The average particle size is found to be from 35 to 90 nm and the unit cell parameter “a” is calculated as from 8.39 to 8.89 Å. The cation distributions are estimated from X-ray diffraction intensities of various planes. The XRD studies have verified the quality of the synthesis of compounds and have shown the differences in the positions of the diffraction peaks due to the change in concentration of copper ions. TEM pictures clearly indicating that fundamental unit is composed of octahedral and tetrahedral blocks and joined strongly. The selected area electron diffraction (SAED) of the ferrite system shows best crystallinity is obtained when Cu content is very. Some of the d-plane spacings are exactly coinciding with XRD values. EPR spectra is compositional dependent at lower Al/Cu concentration EPR spectra is due to Fe3+ and at a higher content of Al/Cu the EPR spectra is due to Cu2+. Absence of EPR spectra at room temperature indicates that the sample is perfectly ferromagnetic. EPR results at low temperature indicate that the sample is paramagnetic, and that copper is placed in the tetragonal elongation (B) site with magnetically non-equivalent ions in the unit cell having strong exchange coupling between them. This property is useful in industrial applications. Nonlinear optical properties of the samples studied using 5 ns laser pulses at 532 nm employing the open aperture z-scan technique indicate that these ferrites are potential candidates for optical limiting applications.

  15. Direct Preparation and Characterization of Copper Pentacyanonitrosylferrate Nanoparticles

    Directory of Open Access Journals (Sweden)

    D. R. Do Carmo

    2015-01-01

    Full Text Available The present work describes the preparation of nanoparticles of copper pentacyanonitrosyl complexes starting from the compound sodium nitroprusside. Copper pentacyanonitrosylferrate (NCuNP nanoparticles were successfully synthesized by using deionized water and formamide as solvent. The material was characterized by Fourier-transforming infrared spectroscopy (FT-IR, X-ray diffraction (XRD, ultraviolet-visible (UV-Vis spectroscopy, scanning electron microscopy (SEM, energy dispersive X-ray spectroscopy (EDX, and cyclic voltammetry (CV. The results revealed that the electronic spectra of NCuNP exhibited a broad intervalence charge transfer band at 685 nm. An XRD peak broadening pattern of the NCuNP was verified, indicating a particle decrease when formamide is used. The particle size of NCuNP is estimated to be 80 nm. The cyclic voltammogram of the modified graphite paste electrode with NCuNP showed two redox pairs with formal potentials Eθ′=0.36 V and Eθ′=0.78 V (ν=20 mV s−1; KCl 1.0 M, attributed to the redox process CuI/ CuII and [FeII(CN5NO]/[FeIII(CN5NO], respectively. The graphite paste electrode with NCuNP presents electrocatalytic response for Sulfite determination.

  16. Preparation and Characterization of Copper-Nickel Bulk Nanocrystals

    Institute of Scientific and Technical Information of China (English)

    WU Xiaoqiang; TANG Yongjian; WANG Lan; AN Xuguang; YI Zao; SUN Weiguo

    2014-01-01

    Copper-nickel nanoparticle was directly prepared by flow-levitation method (FL) and sintered by vacuum sintering of powder (VSP) method. Several characterizations, such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential thermal analysis (DTA), and energy-dispersive X-ray spectroscopy (EDX) were used to investigate the prepared nanostructures. The results of the study show that FL method could prepare high purity Cu-Ni nanocrystals of uniform spheres with size distribution between 20 and 90 nm. After sintering the bulk nanocrystalline copper-nickel has obvious thermal stability and the surface Webster hardness increases with the rising sintering temperature. At the temperature of 900℃, the specimen shows higher surface Webster hardness, which is about two times of traditional materials. When the sintering temperature arrives at 1 000℃the relative density of bulk nanocrystals can reach 97.86 percent. In this paper, the variation tendency of porosity, phase and particles size of bulk along with the changing of sintering temperature have been studied.

  17. Characterization of copper resistant ciliates: Potential candidates for ...

    African Journals Online (AJOL)

    ... of copper resistant ciliates: Potential candidates for consortia of organisms used in bioremediation of wastewater. ... African Journal of Biotechnology ... Copper is one of such contaminant found in the wastewater of local industries.

  18. Characterization and Recovery of Valuables from Waste Copper Smelting Slag

    Science.gov (United States)

    Prince, Sarfo; Young, Jamie; Ma, Guojun; Young, Courtney

    Silicate slags produced from smelting copper concentrates contains valuables such as Cu and Fe as well as heavy metals such as Pb and As which are considered hazardous. In this paper, various slags were characterized with several techniques: SEM-MLA, XRD, TG-DTA and ICP-MS. A recovery process was developed to separate the valuables from the silicates thereby producing value-added products and simultaneously reducing environmental concerns. Results show that the major phases in air-cooled slag are fayalite and magnetite whereas the water-cooled slag is amorphous. Thermodynamic calculations and carbothermal reduction experiments indicate that most of Cu and Fe can be recovered from both types using minor amounts of lime and alumina and treating at 1350°C (1623K) or higher for 30 min. The secondary slag can be recycled to the glass and/or ceramic industries.

  19. Electrochemical synthesis and structural characterization of a novel mixed-valence copper(I)-copper(II) complex: {[bis(ethylenediamine)copper(II)] bis[diiodocuprate(I)]}.

    Science.gov (United States)

    Fotouhi, Lida; Dehghanpour, Saeed; Heravi, Majid M; Ardakani, Mahboobeh Dashti

    2007-07-12

    A novel, mixed-valent copper(I)-copper(II) complex, {[bis(ethylene-diamine)copper(II)] bis[diiodocuprate(I)]} (1), has been prepared by electrochemical dissolution of a sacrificial copper anode in a solution of ethylenediamine (en), I2 and tetraethylammoniumperchlorate (TEAP) as supporting electrolyte in acetonitrile (AcN)and characterized by single-crystal X-ray structure determination. The crystal structure of the complex 1 shows that it consists of a CuI2 polymer formed from I- ligands bridging Cu(I) ions, with a nearly square planar geometry of bivalent Cu(II) atoms chelated by two ethylenediamine ligands. The results also show that direct electrosynthesis of the complex had high current efficiency, purity and electrolysis yield.

  20. Orion FSW V and V and Kedalion Engineering Lab Insight

    Science.gov (United States)

    Mangieri, Mark L.

    2010-01-01

    NASA, along with its prime Orion contractor and its subcontractor s are adapting an avionics system paradigm borrowed from the manned commercial aircraft industry for use in manned space flight systems. Integrated Modular Avionics (IMA) techniques have been proven as a robust avionics solution for manned commercial aircraft (B737/777/787, MD 10/90). This presentation will outline current approaches to adapt IMA, along with its heritage FSW V&V paradigms, into NASA's manned space flight program for Orion. NASA's Kedalion engineering analysis lab is on the forefront of validating many of these contemporary IMA based techniques. Kedalion has already validated many of the proposed Orion FSW V&V paradigms using Orion's precursory Flight Test Article (FTA) Pad Abort 1 (PA-1) program. The Kedalion lab will evolve its architectures, tools, and techniques in parallel with the evolving Orion program.

  1. FSW Numerical Simulation of Aluminium Plates by SYSWELD - Part II

    Directory of Open Access Journals (Sweden)

    Jančo Roland

    2016-11-01

    Full Text Available Friction Stir Welding (FSW is one of the most effective solid state joining processes and has numerous potential applications in many industries. The simulation process can provide the evolution of physicals quantities such as temperature, metallurgical phase proportions, stress and strain which can be easily measured during welding. The numerical modelling requires the modelling of the complex interaction between thermal, metallurgical and mechanical phenomena. The aim of this paper is to describe the thermal-fluid simulation of FSW using the finite element method. In the theoretical part of paper heating is provided by the material flow and contact condition between the tool and the welded material. Thermal-mechanical results from the numerical simulation using SYSWELD are also presented for aluminium alloy.

  2. FSW Numerical Simulation of Aluminium Plates by Sysweld - Part I

    Directory of Open Access Journals (Sweden)

    Jančo Roland

    2016-07-01

    Full Text Available Friction Stir Welding (FSW is one of the most effective solid state joining processes and it has numerous potential applications in many industries. The simulation process can provide the evolution of physical quantities such as temperature, metallurgical phase proportions, stress and strain which can be easily measured during welding. The numerical modelling requires the modelling of a complex interaction between thermal, metallurgical and mechanical phenomena. The aim of this paper is to describe the thermal-fluid simulation of FSW using the finite element method. In the theoretical part of the paper heating is provided by the material flow and contact condition between the tool and the welded material. The thermal-fluid results from the numerical simulation for aluminium alloy using SYSWELD are also presented in this paper.

  3. Development of a New Joint Geometry for FSW

    Science.gov (United States)

    Penalva, M. L.; Otaegi, A.; Pujana, J.; Rivero, A.

    2009-11-01

    Friction Stir Welding (FSW) is an emerging solid state joining technology that allows welding most aluminum alloys that otherwise are difficult to weld by using conventional fusion based technologies. The technology is of particular interest for transport applications, since welded structures are considered to offer cost and weight savings. From a point of view of the joint geometries, FSW is mature for simple configurations. Most work to date has concentrated on butt welds and, only to a certain degree, on overlap configurations. Different designs such as T-sections, corner welds, box sections… are then principally restricted to the use of butt weld configurations. However, it is necessary for FSW to be able to be applied to new geometries in order to spread its use to a wider range of applications. Present work explores the feasibility of producing corner fillet geometries using FSW. Although such a kind of geometry has traditionally been considered unfeasible for the process, it seems to have the greatest potential to be used for T-joint configurations, a recurrent design pattern in transport applications. In order to study the feasibility of the proposed new joint geometry, a specific tool has been developed and a set of welds has been produced with it. Microstructure of the produced welds has been analyzed. According to the obtained results, the proposed joint geometry seems to be feasible. Main problem pending to solve is how to avoid the formation of a tunnel defect in the weld centre line due to a suck effect of the tool on the stirred material. Further improvements are proposed to produce welds with acceptable quality.

  4. FSW Numerical Simulation of Aluminium Plates by Sysweld - Part I

    OpenAIRE

    Jančo Roland; Écsi Ladislav; Élesztős Pavel

    2016-01-01

    Friction Stir Welding (FSW) is one of the most effective solid state joining processes and it has numerous potential applications in many industries. The simulation process can provide the evolution of physical quantities such as temperature, metallurgical phase proportions, stress and strain which can be easily measured during welding. The numerical modelling requires the modelling of a complex interaction between thermal, metallurgical and mechanical phenomena. The aim of this paper is to d...

  5. FSW Numerical Simulation of Aluminium Plates by SYSWELD - Part II

    OpenAIRE

    Jančo Roland; Écsi Ladislav; Élesztős Pavel

    2016-01-01

    Friction Stir Welding (FSW) is one of the most effective solid state joining processes and has numerous potential applications in many industries. The simulation process can provide the evolution of physicals quantities such as temperature, metallurgical phase proportions, stress and strain which can be easily measured during welding. The numerical modelling requires the modelling of the complex interaction between thermal, metallurgical and mechanical phenomena. The aim of this paper is to d...

  6. Advances in the numerical simulation of 3D FSW processes

    OpenAIRE

    Agelet de Saracibar Bosch, Carlos; Chiumenti, Michèle; Cervera Ruiz, Miguel; Dialami, Narges; Santiago, Diego de; Lombera, Guillermo

    2011-01-01

    This work deals with the computational modeling and numerical simulation of 3D Friction Stir Welding (FSW) processes. Eulerian and ALE formulations have been used to solve the quasi-static thermal transient governing equations. Mixed P2/P1/P2+SUPG and subgrid-scale stabilized P1/P1/P1 velocity/pressure/temperature elements have been implemented. Norton-Hoff and Sheppard-Wright rigid thermoplastic material models have been considered. Computational visualization techniques using tracers have b...

  7. A Computational Model for the Numerical Simulation of FSW Processes

    Science.gov (United States)

    Agelet de Saracibar, C.; Chiumenti, M.; Santiago, D.; Cervera, M.; Dialami, N.; Lombera, G.

    2010-06-01

    In this paper a computational model for the numerical simulation of Friction Stir Welding (FSW) processes is presented. FSW is a new method of welding in solid state in which a shouldered tool with a profile probe is rotated and slowly plunged into the joint line between two pieces of sheet or plate material which are butted together. Once the probe has been completely inserted, it is moved with a small tilt angle in the welding direction. Here a quasi-static, thermal transient, mixed multiscale stabilized Eulerian formulation is used. Norton-Hoff and Sheppard-Wright rigid thermo-viscoplastic material models have been considered. A staggered solution algorithm is defined such that for any time step, the mechanical problem is solved at constant temperature and then the thermal problem is solved keeping constant the mechanical variables. A pressure multiscale stabilized mixed linear velocity/linear pressure finite element interpolation formulation is used to solve the mechanical problem and a convection multiscale stabilized linear temperature interpolation formulation is used to solve the thermal problem. The model has been implemented into the in-house developed FE code COMET. Results obtained in the simulation of FSW process are compared to other numerical results or experimental results, when available.

  8. Photocatalysis; IV. Preparation and characterization of a stable copper(I) triflate-trans-cycloheptene complex

    NARCIS (Netherlands)

    Evers, J.T.M.; Mackor, A.

    1979-01-01

    When copper(I) triflate·cis‐cycloheptene is irradiated at 254 nm in n‐hexane solution, cis → trans‐isomerization occurs and the stable complex copper (I) triflate·trans‐cycloheptene precipitates. This complex has been isolated, purified and characterized by elemental analysis and by its 1H and 13C N

  9. Caracterização microestrutural e comportamento mecânico das ligas de alumínio AA2139 T3 e T8 soldadas por fricção rotativa com mistura Microstructural characterization and mechanical behavior of an AA2139 T3 and T8 aluminum alloy joined by friction stir welding (FSW

    Directory of Open Access Journals (Sweden)

    Vinícius Toledo Saccon

    2010-12-01

    Full Text Available Este trabalho visou analisar a caracterização microestrutural e o comportamento mecânico das ligas de alumínio AA2139 T3 e T8 quando são soldadas pelo processo Soldagem por Fricção Rotativa com Mistura, o qual é realizado na fase sólida. A análise microestrutural foi realizada utilizando microscopia óptica e eletrônica de varredura, e o comportamento mecânico foi avaliado através de medidas de microdureza e ensaio de tração convencional complementado pelo sistema ARAMIS. As ligas foram soldadas nos mesmos parâmetros de soldagem e com a mesma ferramenta, a fim de avaliar a qualidade da junta soldada para as duas condições de tratamento térmico, T3 e T8. Os resultados obtidos mostraram soldas resistentes para ambos os tratamentos térmicos, porém com melhores propriedades mecânicas para a liga AA2139 T3.This work aimed to study the microstructural characterization and mechanical behavior of AA2139 T3 and T8 aluminum alloys joined by FSW - Friction Stir Welding. The microstructural analysis has been done using optical microscope and scanning electron microscopy, and the mechanical analysis were evaluate through microhardness testing and conventional tensile test using the ARAMIS system . Each alloy were welded using the same welding parameters and the same tool in order to evaluate the joint quality for both heat treatment used for this work, T3 and T8. The result showed sounds joints for both heat treatments, although with better mechanical properties for the alloy AA2139 T3.

  10. Preparation and Characterization of Directionally Freeze-cast Copper Foams

    Directory of Open Access Journals (Sweden)

    Aurelia I. Cuba Ramos

    2012-08-01

    Full Text Available Because of their excellent thermal and electric conductivities, copper foams are ideally suited for applications such as heat exchangers, catalyst supports and EMI-shields. Here, we demonstrate the preparation of copper with ~80% aligned, elongated, interconnected pores via directional freeze casting, a well established processing technique for porous ceramics. First, an aqueous slurry of 40−80 nm cupric oxide powders was directionally solidified, resulting in a preform consisting of elongated, aligned dendrites of pure ice separated by interdendritic ice walls with high oxide powder content. Oxide rather than metallic nanometric particles are used, as the latter would oxidize rapidly and uncontrollably when suspended in the aqueous solution used during directional casting. The preforms were then freeze-dried to sublimate the ice and sintered in a hydrogen-bearing atmosphere to reduce the copper oxide to metallic copper particles and densify these copper particles. Microstructural analysis of the copper foams shows that three types of porosities are present: (i aligned, elongated pores replicating the ice dendrites created during the freeze-casting process; (ii micro-porosity in the partially sintered copper walls separating the elongated pores; and (iii cracks in these copper walls, probably created because of shrinkage associated with the reduction of the oxide powders.

  11. Chemical and mineralogical characterizations of a copper converter slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A copper converter slag was examined chemically and mineralogically to determine its existing phases, in particular those containing Co and Cu. The slag consists predominantly of fayalite and magnetite, together with some glass,chalcocite, and metallic copper. Copper is entrapped in the slag mostly as chalcocite and metallic copper, as well as trace copper oxide. There was no indication of any independent Co mineral in the slag, but Co was found to be enriched in fayalite and megnetite as solid solution, although Co was detected in all the phases of the slag by SEM-EDX (scanning electron microscopy equipped with model EDAX-9100 energy dispersive spectrometer) and WDS (model WDX-2A X-ray wave-length dispersive spectrometer).

  12. Freshwater Sediment Characterization Factors of Copper Oxide Nanoparticles

    Science.gov (United States)

    Pu, Yubing; Laratte, Bertrand; Ionescu, Rodica Elena

    2017-01-01

    Wide use of engineered nanoparticles (ENPs) is likely to result in the eventually accumulation of ENPs in sediment. The benthic organisms living in sediments may suffer relatively high toxic effects of ENPs. This study has selected copper oxide nanoparticles (nano-CuO) as a research object. To consider the impacts of spatial heterogeneity on ENPs toxicity, the characterization factor (CF) derived from life cycle assessment (LCA) methodology is used as an indicator in this study. A nano-specific fate model has been used to calculate the freshwater sediment fate factor (FF) of nano-CuO. A literature survey of the nano-CuO toxicology values has been performed to calculate the effect factor (EF). Seventeen freshwater sediment CFs of nano-CuO are proposed as recommended values for subcontinental regions. The region most likely to be affected by nano-CuO is northern Australia (CF of 21.01·103 CTUe, comparative toxic units) and the least likely is northern Europe and northern Canada (CF of 8.55·103 CTUe). These sediment CFs for nano-CuO could be used in the future when evaluating the ecosystem impacts of products containing nano-CuO by LCA method.

  13. Electrochemical Synthesis and Structural Characterization of a Novel Mixed-valence Copper (I-copper (II Complex: {[Bis(ethylenediamine Copper (II] Bis[diiodocuprate (I]}

    Directory of Open Access Journals (Sweden)

    Mahboobeh Dashti Ardakani

    2007-07-01

    Full Text Available A novel, mixed-valent copper(I-copper(II complex, {[bis(ethylene-diaminecopper(II] bis[diiodocuprate(I]} (1, has been prepared by electrochemicaldissolution of a sacrificial copper anode in a solution of ethylenediamine (en, I2 andtetraethylammoniumperchlorate (TEAP as supporting electrolyte in acetonitrile (AcNand characterized by single-crystal X-ray structure determination. The crystal structure ofthe complex 1 shows that it consists of a CuI2 polymer formed from I- ligands bridgingCu(I ions, with a nearly square planar geometry of bivalente Cu(II atoms chelated by twoethylenediamine ligands. The results also show that direct electrosynthesis of the complexhad high current efficiency, purity and electrolysis yield.

  14. Experimental investigation of hardness of FSW and TIG joints of Aluminium alloys of AA7075 and AA6061

    Directory of Open Access Journals (Sweden)

    Chetan Patil

    2016-07-01

    Full Text Available This paper reports hardness testing conducted on welded butt joints by FSW and TIG welding process on similar and dissimilar aluminium alloys. FSW joints were produced for similar alloys of AA7075T651 and dissimilar alloys of AA7075T651- AA6061T6. The Friction stir welds of AA7075 & AA6061 aluminium alloy were produced at different tool rotational speeds of 650,700, 800, 900, 1000 and transverse speed of 30, 35, 40 mm/min. TIG welding was conducted along the rolling direction of similar and dissimilar aluminium plates. The Brinell hardness testing techniques were employed to conduct the tests; these tests were conducted on the welds to ascertain the joint integrity before characterization to have an idea of the quality of the welds

  15. Characterization and recovery of copper values from discarded slag.

    Science.gov (United States)

    Das, Bisweswar; Mishra, Barada Kanta; Angadi, Shivakumar; Pradhan, Siddharth Kumar; Prakash, Sandur; Mohanty, Jayakrushna

    2010-06-01

    In any copper smelter large quantities of copper slag are discarded as waste material causing space and environmental problems. This discarded slag contains important amounts of metallic values such as copper and iron. The recovery of copper values from an Indian smelter slag that contains 1.53% Cu, 39.8% Fe and 34.65% SiO(2) was the focus of the present study. A complete investigation of the different phases present in the slag has been carried out by means of optical microscopy, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. It is observed that iron and silica are mostly associated with the fayalite phase whereas copper is present in both oxide and sulfide phases. These oxide and sulfide phases of copper are mostly present within the slag phase and to some extent the slag is also embedded inside the oxide and sulfide phases. The recovery of copper values from the discarded slag has been explored by applying a flotation technique using conventional sodium isopropyl xanthate (SIX) as the collector. The effects of flotation parameters such as pH and collector concentration are investigated. Under optimum flotation conditions, it is possible to achieve 21% Cu with more than 80% recovery.

  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. Unprecedented copper(I) bifluoride complexes: synthesis, characterization and reactivity.

    Science.gov (United States)

    Vergote, Thomas; Nahra, Fady; Welle, Alexandre; Luhmer, Michel; Wouters, Johan; Mager, Nathalie; Riant, Olivier; Leyssens, Tom

    2012-01-16

    To be or not to bifluoride: Two synthetic pathways to unprecedented N-heterocyclic carbene copper(I) bifluoride complexes have been developed. Catalytic tests demonstrated that copper(I) bifluorides are very efficient catalysts, which do not require any additional activating agent. The first Cu-catalyzed diastereoselective allylation of (R)-N-tert-butanesulfinyl aldimines was also established. The method enables efficient, simple and general synthesis of enantiomerically enriched homoallylic amines at room temperature in high yields.

  18. Electrochemical synthesis and characterization of copper (I oxide

    Directory of Open Access Journals (Sweden)

    Bugarinović Sanja J.

    2009-01-01

    Full Text Available The quest and need for clean and economical energy sources have increased interest in the development of thin film cells technologies. Electrochemical deposition is an attractive method for synthesis of thin films. It offers the advantages of low synthesis temperature, low cost and high purity. Copper (I oxide or cuprous oxide is an oxide semiconductor which is used as the anodic material in the form of thin film in lithium batteries and solar cells. The cathodic process of synthesis of cuprous oxide thin film is carried out in a potentiostatic mode from the organic electrolyte. The process parameters are chosen in that way to accomplish maximum difference between the potentials at which Cu2O and CuO are obtained. The electrochemical characterization was carried out by cyclic voltammetry. The electrodeposition techniques are particularly well suited for the deposition of single elements but it is also possible to carry out simultaneous depositions of several elements and syntheses of well-defined alternating layers of metals and oxides with thicknesses down to a few nm. Nanomaterials exhibit novel physical properties and play an important role in fundamental research. In addition, cuprous oxide is commonly used as a pigment, a fungicide, and an antifouling agent for marine paints. It is insoluble in water and organic solvents. This work presents the examinations of the influence of bath, temperature, pH and current density on the characteristics of electrochemically synthesized cuprous oxide. In the 'classic' process of synthesis, which is carried out under galvanostatic conditions on the anode, the grain size of the powder decreases with the increase in current density while the grain colour becomes lighter. The best commercial quality of the Cu2O (grain size, colour, content of choride was obtained at the temperature of 80°C, concentration of NaCl of 3 mol/dm3 and current density of 400 A/m2.

  19. Microstructural Aspects in FSW and TIG Welding of Cast ZE41A Magnesium Alloy

    Science.gov (United States)

    Carlone, Pierpaolo; Astarita, Antonello; Rubino, Felice; Pasquino, Nicola

    2016-04-01

    In this paper, magnesium ZE41A alloy plates were butt joined through friction stir welding (FSW) and Tungsten Inert Gas welding processes. Process-induced microstructures were investigated by optical and SEM observations, EDX microanalysis and microhardness measurements. The effect of a post-welded T5 heat treatment on FSW joints was also assessed. Sound joints were produced by means of both techniques. Different elemental distributions and grain sizes were found, whereas microhardness profiles reflect microstructural changes. Post-welding heat treatment did not induce significant alterations in elemental distribution. The FSW-treated joint showed a more homogeneous hardness profile than the as-welded FSW joint.

  20. Crack initiation and propagation paths in small diameter FSW 6082-T6 aluminium tubes under fatigue loading

    Directory of Open Access Journals (Sweden)

    Roberto Tovo

    2016-03-01

    Full Text Available This paper reports results of fatigue tests of friction stir welded (FSW aluminium tubes. Relatively small 38 mm diameter tubes were used and hence an automated FSW process using a retracting tool was designed for this project, as the wall thickness of the aluminium tube was similar to the diameter of the FSW tool. This is a more complex joint geometry to weld than the more usual larger diameter tube reported in the literature. S-N fatigue testing was performed using load ratios of R = 0.1 and R = -1. Crack path analysis was performed using both low magnification stereo microscopy and scanning electron microscopy, in order to identify crack initiation sites and to determine the direction of crack propagation. Work is still in progress to follow the crack path through the various microstructural zones associated with the weld. A simple statistical analysis was used to characterize the most typical crack initiation site. This work forms part of a wider project directed at determining multiaxial fatigue design rules for small diameter 6082-T6 aluminium tubes that could be of use in the ground vehicle industry.

  1. Tensiones residuales en uniones soldadas por FSW en aluminio 7075-T651 Residual stresses in 7075-T651 FSW joint

    Directory of Open Access Journals (Sweden)

    Leonardo N. Tufaro

    2012-12-01

    Full Text Available Las tensiones residuales pueden ser un aspecto de relevancia en la integridad estructural de componentes en servicio, pudiendo presentar una importante influencia sobre la vida a la fatiga, entre otros mecanismos de falla. El proceso de soldadura por fricción-agitación (FSW ha revolucionado en los últimos años el campo de la tecnología de la soldadura. Su mayor aplicación se ha dado en las aleaciones de aluminio, aunque hoy en día se utiliza para prácticamente todos los materiales. Una de las ventajas enunciadas de este proceso es el menor nivel de tensiones residuales resultantes, debido a que se produce en estado sólido por lo que los gradientes térmicos durante la soldadura son menores. Entre las aleaciones de aluminio de uso estructural, las aleaciones termoenvejecibles de la serie 7XXX se utilizan habitualmente en la industria aeronáutica y aeroespacial debido a su alta resistencia mecánica. El objetivo del presente trabajo es analizar el efecto de la velocidad de avance en FSW sobre las tensiones residuales en juntas de aluminio AA7075-T651, mediante la técnica de seccionamiento. Se soldaron probetas de dicha aleación de 150x150x4mm mediante FSW, variando la velocidad de avance entre 51 y 206 mm.min-1. Durante la soldadura se adquirieron los ciclos térmicos. Posteriormente se midieron las tensiones residuales longitudinales a distintas distancias del cordón de soldadura, en cada caso. A partir de los ciclos térmicos adquiridos se obtuvieron los gradientes térmicos en la zona de medición. Las tensiones residuales máximas se encontraron entre 52 y 78 MPa, correspondiente entre 10 y 15 % del límite de fluencia del material. Las mismas aumentaron con la velocidad de avance, consistentemente con un aumento en el gradiente térmico observado. Dichos valores de tensiones residuales son menores que los obtenidos para la soldadura de estos materiales mediante procesos del tipo GMAW.Residual stresses could be a relevant issue in

  2. Synthesis, Characterization and DNA Cleavage of Copper(II ...

    African Journals Online (AJOL)

    (UV) light. Results: ATR-FTIR confirmed the formation of copper(II) complex with DTT by binding through thiol group based on the .... DNA cleavage detection ... The infrared spectra of pure DTT and its Cu(II) .... and iron complexes. J Phys Conf ...

  3. Differential Evolution algorithm applied to FSW model calibration

    Science.gov (United States)

    Idagawa, H. S.; Santos, T. F. A.; Ramirez, A. J.

    2014-03-01

    Friction Stir Welding (FSW) is a solid state welding process that can be modelled using a Computational Fluid Dynamics (CFD) approach. These models use adjustable parameters to control the heat transfer and the heat input to the weld. These parameters are used to calibrate the model and they are generally determined using the conventional trial and error approach. Since this method is not very efficient, we used the Differential Evolution (DE) algorithm to successfully determine these parameters. In order to improve the success rate and to reduce the computational cost of the method, this work studied different characteristics of the DE algorithm, such as the evolution strategy, the objective function, the mutation scaling factor and the crossover rate. The DE algorithm was tested using a friction stir weld performed on a UNS S32205 Duplex Stainless Steel.

  4. Synthesis and characterization of vanadiumoxidecatalysts supported on copper orthophosphates

    Science.gov (United States)

    Ouchabi, M.; Baalala, M.; Elaissi, A.; Loulidi, I.; Bensitel, M.

    2017-03-01

    Synthesis of a pure copper orthophosphate (CuP) prepared by Coprecipitation, and CuP modified by impregnation of vanadium (2-12 wt % of V2O5) have been carried out. The solids obtained were investigated as synthesized or after calcination by various physico-chemical techniques such as X-Ray Diffraction (XRD), Infrared Spectroscopy (IR), Thermogravimetric analysis (TGA), and differential thermal analysis (DTA). The results revealed that the solids V/CuP consisted of copper orthophosphate Cu3(PO4)2 as major phases, together with V2O5 as minor phase. The diffraction lines of V2O5 increase by increasing the vanadium content.

  5. Thermal characterization and properties of a copper-diamond composite

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Pin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Chavez, Thomas P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); DiAntonio, Christopher Brian [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Coker, Eric Nicholas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    The thermal properties of a commercial copper-diamond composite were measured from below -50°C to above 200°C. The results of thermal expansion, heat capacity, and thermal diffusivity were reported. These data were used to calculate the thermal conductivity of the composite as a function of temperature in the thickness direction. These results are compared with estimated values based on a simple mixing rule and the temperature dependence of these physical properties is represented by curve fitting equations. These fitting equations can be used for thermal modeling of practical devices/systems at their operation temperatures. The results of the mixing rule showed a consistent correlation between the amount of copper and diamond in the composite, based on density, thermal expansion, and heat capacity measurements. However, there was a disparity between measured and estimated thermal diffusivity and thermal conductivity. These discrepancies can be caused by many intrinsic material issues such as lattice defects and impurities, but the dominant factor is attributed to the large uncertainty of the interfacial thermal conductance between diamond and copper.

  6. Characterization of Copper Oxide Nanoparticles Fabricated by the Sol-Gel Method

    Science.gov (United States)

    Kayani, Zohra Nazir; Umer, Maryam; Riaz, Saira; Naseem, Shahzad

    2015-10-01

    Copper oxide nanoparticles were successfully prepared by a sol-gel technique. An aqueous solution of copper nitrate Cu(NO3)2 and acetic acid was used as precursor. On addition of sodium hydroxide (NaOH) a precipitate of copper oxide was immediately formed. The copper oxide nanoparticles were characterized by use of x-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential thermal analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometry, and scanning electron microscopy (SEM). The XRD pattern contained sharp peaks of copper oxide nanoparticles with mixed cuprite and tenorite phases. Use of the Debye-Scherer equation showed that the crystallite size of the copper oxide nanoparticles increased with increasing annealing temperature. FTIR spectra revealed vibration of the CuO band at 473 cm-1; a band at 624 cm-1 was attributed to Cu2O. Maximum coercivity and saturation magnetization of the nanoparticles were 276 Oe and 0.034 emu/g, respectively. SEM micrographs of the nanoparticles revealed the presence of spherical nanoparticles of the tenorite phase whereas the cuprite phase was in the form of a compact deposit.

  7. Removal of Copper by Eichhornia crassipes and the Characterization of Associated Bacteria of the Rhizosphere System

    Directory of Open Access Journals (Sweden)

    Raisa Kabeer

    2014-06-01

    Full Text Available Excess doses of trace element contamination make conventional water treatment methods less effective and more expensive, where in alternative biotechnological applications open up new opportunities with their reduced cost and lesser impacts to the environment. In the present investigation, effectiveness of aquatic macrophyte Eichhornia crassipes was tested for the removal of copper in laboratory conditions. Water samples were collected from macrophytes natural habitat and water tubs used for growing E. crassipes and analysed along with plant tissues for Cu content. The work also characterized the associated microbiota of the rhizosphere system of the E. crassipes as well as the wetland system of its occurrence. Copper concentration of the wetland water samples ranged from 0.009 to 0.03ppm. Six bacterial genera (Acinetobacter, Alcaligenes, Bacillus, Kurthia, Listeria and Chromobacterium were represented in rhizosphere of E.crassipes and 4 bacterial genera (Acinetobacter, Bacillus, Listeria and Chromobacterium were recorded in wetland water samples. Copper resistance studies of the bacterial isolates showed that out of 26 isolates from rhizosphere and 19 strains from water samples,12 of them showed low resistance (80% of copper during 15 days experiment. Copper accumulation was found to be high in the root followed by leaf and petiole. Results of the present study concluded that E. crassipes is an efficient plant for the removal of copper.

  8. Geochemical Characterization of Copper Tailings after Legume Revegetation

    Directory of Open Access Journals (Sweden)

    Justine Perry T. Domingo

    2014-12-01

    Full Text Available Knowledge on the geochemistry of mine tailings is important in understanding the challenges in establishing vegetation cover on tailings dumps and mined out areas. In this study, the mineralogy and trace element composition of copper tailings were examined. Two legume species, Calopogonium mucunoides and Centrosema molle, were utilized to investigate the possible effects of these plants in the geochemical development of mine tailings into soil-like material. The initial mineralogical and chemical analysis of the tailings samples indicated poor conditions for plant growth—minimal levels of major nutrients and organic matter as well as elevated copper concentrations. Despite these conditions, the two legume species exhibited good growth rates. Both legumes have likewise signif icantly reduced heavy metal concentrations in the tailings, indicating the possibility of metal hyperaccumulation in the plant tissue. The mineral composition has been retained even after revegetation; nevertheless, breakdown of primary minerals and subsequent formation of clay minerals were detected. These results provide insights on the transformation of toxic materials into habitable substrates for sustained plant growth.

  9. Fabrication and Characterization of Copper System Compound Semiconductor Solar Cells

    Directory of Open Access Journals (Sweden)

    Ryosuke Motoyoshi

    2010-01-01

    Full Text Available Copper system compound semiconductor solar cells were produced by a spin-coating method, and their cell performance and structures were investigated. Copper indium disulfide- (CIS- based solar cells with titanium dioxide (TiO2 were produced on F-doped SnO2 (FTO. A device based on an FTO/CIS/TiO2 structure provided better cell performance compared to that based on FTO/TiO2/CIS structure. Cupric oxide- (CuO- and cuprous oxide- (Cu2O- based solar cells with fullerene (C60 were also fabricated on FTO and indium tin oxide (ITO. The microstructure and cell performance of the CuO/C60 heterojunction and the Cu2O:C60 bulk heterojunction structure were investigated. The photovoltaic devices based on FTO/CuO/C60 and ITO/Cu2O:C60 structures provided short-circuit current density of 0.015 mAcm−2 and 0.11 mAcm−2, and open-circuit voltage of 0.045 V and 0.17 V under an Air Mass 1.5 illumination, respectively. The microstructures of the active layers were examined by X-ray diffraction and transmission electron microscopy.

  10. Characterization and Reactivity Studies of a Terminal Copper-Nitrene Species.

    Science.gov (United States)

    Corona, Teresa; Ribas, Lídia; Rovira, Mireia; Farquhar, Erik R; Ribas, Xavi; Ray, Kallol; Company, Anna

    2016-11-02

    High-valent terminal copper-nitrene species have been postulated as key intermediates in copper-catalyzed aziridination and amination reactions. The high reactivity of these intermediates has prevented their characterization for decades, thereby making the mechanisms ambiguous. Very recently, the Lewis acid adduct of a copper-nitrene intermediate was trapped at -90 °C and shown to be active in various oxidation reactions. Herein, we describe for the first time the synthesis and spectroscopic characterization of a terminal copper(II)-nitrene radical species that is stable at room temperature in the absence of any Lewis acid. The azide derivative of a triazamacrocyclic ligand that had previously been utilized in the stabilization of aryl-Cu(III) intermediates was employed as an ancillary ligand in the study. The terminal copper(II)-nitrene radical species is able to transfer a nitrene moiety to phosphines and abstract a hydrogen atom from weak C-H bonds, leading to the formation of oxidized products in modest yields. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Preparation, characterization and application of nanosized copper ferrite photocatalysts for dye degradation under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zaharieva, Katerina, E-mail: zaharieva@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Rives, Vicente, E-mail: vrives@usal.es [GIR-QUESCAT, Dpto. Química Inorgánica, Universidad de Salamanca, 37008 Salamanca (Spain); Tsvetkov, Martin, E-mail: mptsvetkov@gmail.com [Faculty of Chemistry and Pharmacy, St. Kliment Ohridski University of Sofia, 1 J. Bourchier Blvd., 1164 Sofia (Bulgaria); Cherkezova-Zheleva, Zara, E-mail: zzhel@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Kunev, Boris, E-mail: bkunev@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Trujillano, Raquel, E-mail: rakel@usal.es [GIR-QUESCAT, Dpto. Química Inorgánica, Universidad de Salamanca, 37008 Salamanca (Spain); Mitov, Ivan, E-mail: mitov@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Milanova, Maria, E-mail: nhmm@wmail.chem.uni-sofia.bg [Faculty of Chemistry and Pharmacy, St. Kliment Ohridski University of Sofia, 1 J. Bourchier Blvd., 1164 Sofia (Bulgaria)

    2015-06-15

    Nanosized copper ferrite-type materials (Cu{sub x}Fe{sub 3–x}O{sub 4}, 0 ≤ x ≤ 1) have been prepared by combination of co-precipitation and mechanochemical activation and/or thermal treatment. The crystalline structure and morphology of the obtained ferrite nanopowders have been characterized by different instrumental methods, such as Powder X-ray diffraction (PXRD), Mössbauer and FT-IR spectroscopies, specific surface area and porosity measurements, thermal analyses (Differential Thermal Analysis and Thermogravimetric Analysis) and Temperature-Programmed Reduction. The average crystallite size of copper ferrites ranged between 7.8 and 14.7 nm and show a superparamagnetic and collective magnetic excitations nature. The photocatalytic decolorization of Malachite green oxalate under different UV illumination intervals was examined using these copper ferrites as photocatalysts. The results indicate that the prepared nanostructured copper ferrites showed enhanced photocatalytic activity and amount adsorbed Malachite Green dye. The co-precipitated nanosized copper ferrite powder with a low content of copper metal ions in a magnetite host structure (Cu{sub 0.25}Fe{sub 2.75}O{sub 4}) showed an apparent pseudo-first-order rate constant 15.4 × 10{sup −3} min{sup −1} and an amount adsorbed Malachite Green as model organic dye pollutant per 1 g catalyst of 33.4 ppm/g after the dark period. The results confirm that the copper ferrites can be suitable for photocatalytic treatment of wastewaters containing organic dyes. The new aspect of presented investigations is to study the influence of different degree of incorporation of copper ions into the magnetite host structure and preparation methods on the photocatalytic properties of nanosized copper ferrite materials and obtaining of potential photocatalyst (Cu{sub 0.25}Fe{sub 2.75}O{sub 4}) with higher photocatalytic activity (15.4 × 10{sup −3} min{sup −1}) than that of the standard referent Degussa P25 (12 × 10

  12. Molecular Characterization of CTR-type Copper Transporters in an Oceanic Diatom, Thalassiosira oceanica 1005

    Science.gov (United States)

    Kong, L.; Price, N. M.

    2016-02-01

    Copper is an essential micronutrient for phytoplankton growth because of its role as a redox cofactor in electron transfer proteins in photosynthesis and respiration, and a potentially limiting resource in parts of the open sea. Thalassiosira oceanica 1005 can grow at inorganic copper concentrations varying from 10 fmol/L to 10 nmol/L by regulating copper uptake across plasma membrane. Four putative CTR-type copper transporter genes (ToCTR1, ToCTR2, ToCTR3.1 and ToCTR3.2) were identified by BLASTP search against the T. oceanica genome. Predicted gene models were revised by assembled mRNA sequencing transcripts and updated gene models contained all conserved features of characterized CTR-type copper transporters. ToCTR3.1 and ToCTR3.2 may arise from one another by gene duplication as they shared a sequence similarity of 97.6% with a peptide insertion of 5 amino acids at N-terminus of ToCTR3.1. The expression of ToCTR1, ToCTR2 and ToCTR3.1/3.2 was upregulated in low copper concentrations, but only ToCTR3.1/3.2 showed a significant increase (2.5 fold) in copper-starved cells. Both ToCTR3.1 and ToCTR3.2 restored growth of a yeast double mutant, Saccharomyces cerevisiae ctr1Δctr3Δ, in copper deficient medium. GFP-fused ToCTR expression showed that some ToCTR3.1 localized to the plasma membrane but a large portion was retained in the endoplasmic reticulum. Inefficient targeting of ToCTR3.1 to the yeast outer membrane may explain poorer growth compared to the Saccharomyces native ScCTR1 transformant. Thus, diatom CTR genes encoding CTR-type copper transporters show high-affinity copper uptake and their regulation may enable diatoms to survive in ocean environments containing a wide range of copper concentrations.

  13. Alkynyl functionalized iminopyridine copper(I) phosphine complexes: Synthesis, spectroscopic characterization and photophysical properties

    Energy Technology Data Exchange (ETDEWEB)

    Jadhav, A.N.; Chavan, S.S., E-mail: sanjaycha2@rediffmail.com

    2014-04-15

    Some copper(I) complexes of type [Cu(L{sub 1})(PPh{sub 3}){sub 2}/(dppe)]X (1a–6a) and [Cu(L{sub 2})(PPh{sub 3}){sub 2}/(dppe)]X (1b–6b) [where L{sub 1}=N-(2-pyridylmethylene)-4-(trimethylsilylethynyl)aniline, L{sub 2}=N-(2-pyridylmethylene)-4-(phenylethynyl)aniline, PPh{sub 3}=triphenylphosphine, dppe=1,2-bis(diphenylphosphino)ethane, and X=ClO{sub 4}{sup −}, BF{sub 4}{sup −} and PF{sub 6}{sup −}] have been prepared and characterized on the basis of their elemental analyses and spectroscopic studies (IR, UV–visible, {sup 1}H NMR and {sup 31}P NMR). The representative complex of the series [Cu(L{sub 2})(PPh{sub 3}){sub 2}]ClO{sub 4}{sup −} (1b) has been characterized by single crystal X-ray diffraction which reveals that in the complex the central copper(I) ion assumes highly distorted-tetrahedral geometry. The UV–visible spectra indicate that the ancillary phosphine ligands significantly perturb the MLCT state of copper(I) complexes. Room temperature luminescence is observed for all copper(I) complexes in dichloromethane solution, indicating that alkynyl functionality on iminopyridine ligands enhances the emission property of copper(I) complexes and varies considerably with ancillary phosphine ligands. The thermal behavior of complexes revealed that copper(I) complexes with dppe ligand are thermally more stable than PPh{sub 3} complexes. All the complexes exhibit a quasireversible redox behavior corresponding to Cu(I)/Cu(II) couple and are sensitive to phosphine ligand. -- Highlights: • Synthesis of copper(I) complexes of alkynyl functionalized Schiff base. • Characterization by elemental analyses, IR, {sup 1}H NMR and {sup 31}P NMR spectral studies. • Electrochemical properties indicate a quasireversible redox behavior for all copper(I) complexes • All the copper(I) complexes exhibit intraligand (π→π{sup ⁎}) luminescence in dichloromethane.

  14. Characterization of failure processes in tungsten copper composites under fatigue loading conditions

    Science.gov (United States)

    Kim, Yong-Suk; Verrilli, Michael J.; Gabb, Timothy P.

    1989-01-01

    A fractographic and metallographic investigation was performed on specimens of a tungsten fiber reinforced copper matrix composite (9 vol percent), which had experienced fatigue failures at elevated temperatures. Major failure modes and possible failure mechanisms, with an emphasis placed on characterizing fatigue damage accumulation, were determined. Metallography of specimens fatigued under isothermal cyclic loading suggested that fatigue damage initiates in the matrix. Cracks nucleated within the copper matrix at grain boundaries, and they propagated through cavity coalescence. The growing cracks subsequently interacted with the reinforcing tungsten fibers, producing a localized ductile fiber failure. Examinations of interrupted tests before final failure confirmed the suggested fatigue damage processes.

  15. Spectroscopic characterization of schiff base-copper complexes immobilized in smectite clays

    Directory of Open Access Journals (Sweden)

    Patrícia M. Dias

    2010-01-01

    Full Text Available Herein, the immobilization of some Schiff base-copper(II complexes in smectite clays is described as a strategy for the heterogenization of homogeneous catalysts. The obtained materials were characterized by spectroscopic techniques, mostly UV/Vis, EPR, XANES and luminescence spectroscopy. SWy-2 and synthetic Laponite clays were used for the immobilization of two different complexes that have previously shown catalytic activity in the dismutation of superoxide radicals, and disproportionation of hydrogen peroxide. The obtained results indicated the occurrence of an intriguing intramolecular redox process involving copper and the imine ligand at the surface of the clays. These studies are supported by computational calculations.

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

    Science.gov (United States)

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

    2012-04-01

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

  17. Manufacture and characterization of silver and copper nanostructures produced via forcespun Nylon 6 nanofibers

    Science.gov (United States)

    Zhao, Wenqian

    Nylon 6 nanofibers were produced using the ForcespinningRTM method and were deposited with silver or copper thin films using the high vacuum thermal evaporation technique for surface functionalization of nanostructures. The changes in surface composition, morphology and surface energy of native and metallic coated Nylon 6 nanofibers were examined. Their antibacterial properties of native, silver or copper coated Nylon 6 nanofibers were tested. Furthermore, the Nylon 6 nanofibers were used as templates in order to obtain silver or copper nanotubes where the polymer was removed after high temperature calcination. The metallic coated Nylon 6 nanofibers and metallic nanotubes morphology and electrical behavior are characterized using the SEM, STEM, XRD, EDS and electrical measurements.

  18. Nanoscale surface characterization of aqueous copper corrosion: Effects of immersion interval and orthophosphate concentration

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Stephanie L. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); United States Environmental Protection Agency, National Risk Management Research Laboratory (NRMRL), Water Supply and Water Resource Division (WSWRD), Cincinnati, OH 45268 (United States); Sprunger, Phillip T. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Center for Advanced Microstructures and Devices, Synchrotron Radiation Facility of Louisiana State University, Baton Rouge, LA 70803 (United States); Kizilkaya, Orhan [Center for Advanced Microstructures and Devices, Synchrotron Radiation Facility of Louisiana State University, Baton Rouge, LA 70803 (United States); Lytle, Darren A. [United States Environmental Protection Agency, National Risk Management Research Laboratory (NRMRL), Water Supply and Water Resource Division (WSWRD), Cincinnati, OH 45268 (United States); Garno, Jayne C., E-mail: jgarno@lsu.edu [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2013-11-15

    Morphology changes for copper surfaces exposed to different water parameters were investigated at the nanoscale with atomic force microscopy (AFM), as influenced by changes in pH and the levels of orthophosphate ions. Synthetic water samples were designed to mimic physiological chemistries for drinking water, both with and without addition of orthophosphate over a pH range 6.5–9. Copper surfaces treated with orthophosphate as a corrosion inhibitor after 6 and 24 h were evaluated. Tapping mode AFM images revealed dosing of the water with 6 mg/L of orthophosphate was beneficial in retarding the growth of copper by-products. The chemical composition and oxidation state of the surface deposits were characterized with X-ray diffraction (XRD), near edge X-ray absorption fine structure (NEXAFS) spectroscopy and Fourier transform infrared spectroscopy (FTIR).

  19. Printed wiring boards for mobile phones: characterization and recycling of copper.

    Science.gov (United States)

    Kasper, Angela C; Berselli, Guilherme B T; Freitas, Bruno D; Tenório, Jorge A S; Bernardes, Andréa M; Veit, Hugo M

    2011-12-01

    The popularization of mobile phones, combined with a technological evolution, means a large number of scrap and obsolete equipment are discarded every year, thereby causing economic losses and environmental pollution. In the present study, the printed wiring boards scrap of mobile phones were characterized in order to recycle some of the device components, using techniques of mechanical processing, hydrometallurgy and electrometallurgy. The use of the techniques of mechanical processing (milling, particle size classification, magnetic and electrostatic separation) was an efficient alternative to obtain a concentrated fraction (mainly iron in the magnetic fraction and copper in the conductive fraction) and another fraction containing polymers and ceramics. At the end of mechanical processing, a concentrated fraction of metals could be obtained with an average concentration of 60% copper. This concentrated fraction in metals was dissolved in aqua regia and sent to electrowinning to recover 92% of the dissolved copper. The obtained cathodes have a copper content above 95%, which demonstrates the technical feasibility of recovery of copper using the techniques of mechanical processing, hydrometallurgy and electrometallurgy.

  20. Using different chemical methods for deposition of copper selenide thin films and comparison of their characterization.

    Science.gov (United States)

    Güzeldir, Betül; Sağlam, Mustafa

    2015-11-05

    Different chemical methods such as Successive Ionic Layer Adsorption and Reaction (SILAR), spin coating and spray pyrolysis methods were used to deposite of copper selenide thin films on the glass substrates. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray analysis (EDX) spectroscopy and UV-vis spectrophotometry. The XRD and SEM studies showed that all the films exhibit polycrystalline nature and crystallinity of copper selenide thin films prepared with spray pyrolysis greater than spin coating and SILAR methods. From SEM and AFM images, it was observed copper selenide films were uniform on the glass substrates without any visible cracks or pores. The EDX spectra showed that the expected elements exist in the thin films. Optical absorption studies showed that the band gaps of copper selenide thin films were in the range 2.84-2.93 eV depending on different chemical methods. The refractive index (n), optical static and high frequency dielectric constants (ε0, ε∞) values were calculated by using the energy bandgap values for each deposition method. The obtained results from different chemical methods revealed that the spray pyrolysis technique is the best chemical deposition method to fabricate copper selenide thin films. This absolute advantage was lead to play key roles on performance and efficiency electrochromic and photovoltaic devices.

  1. Copper complexes bearing 2-aminobenzothiazole derivatives as potential antioxidant: Synthesis, characterization.

    Science.gov (United States)

    Joseph, J; Janaki, G Boomadevi

    2016-09-01

    Novel copper complexes of Schiff base ligands of 2-aminobenzothiazole derivatives were synthesized by the condensation of Knoevenagel condensate of acetoacetanilide (obtained from substituted benzaldehydes and acetoacetanilide) and 2-aminobenzothiazole. They were characterized by elemental analysis, IR, (1)H NMR, UV-Vis., molar conductance, magnetic susceptibility measurements and electrochemical studies. Based on the magnetic moment and electronic spectral data, square planar geometry has been suggested for all the complexes. Antibacterial and antifungal screening of the ligands and their complexes reveal that all the complexes show higher activities than the ligands. The binding behaviour of the complexes with calf thymus DNA has been investigated by electronic absorption spectra, viscosity measurements and cyclic voltammetry. The DNA binding constants reveal that all these complexes interact with DNA through intercalation binding mode. Superoxide dismutase and antioxidant activities of the copper complexes have also been studied. The antioxidant activities of the complexes showed higher activities. Thermal denaturation studies suggested the nature binding affinity of copper complexes with CT-DNA. All complexes exhibit suitable Cu(II)/Cu(I) redox potential to act as antioxidant enzymes mimic. Further, the copper complexes also showed catalase activity. It is hope that copper complexes were capable of decrease ROS levels or reduce oxidative stress in Alzheimer's patients.

  2. Molten pool characterization of laser lap welded copper and aluminum

    Science.gov (United States)

    Xue, Zhiqing; Hu, Shengsun; Zuo, Di; Cai, Wayne; Lee, Dongkyun; Elijah, Kannatey-Asibu, Jr.

    2013-12-01

    A 3D finite volume simulation model for laser welding of a Cu-Al lap joint was developed using ANSYS FLUENT to predict the weld pool temperature distribution, velocity field, geometry, alloying element distribution and transition layer thickness—all key attributes and performance characteristics for a laser-welded joint. Melting and solidification of the weld pool was simulated with an enthalpy-porosity formulation. Laser welding experiments and metallographic examination by SEM and EDX were performed to investigate the weld pool features and validate the simulated results. A bowl-shaped temperature field and molten pool, and a unique maximum fusion zone width were observed near the Cu-Al interface. Both the numerical simulation and experimental results indicate an arch-shaped intermediate layer of Cu and Al, and a gradual transition of Cu concentration from the aluminum plate to the copper plate with high composition gradient. For the conditions used, welding with Cu on top was found to result in a better weld joint.

  3. Numerical study of aerodynamic characteristics of FSW aircraft with dierent wing positions under supersonic condition

    Institute of Scientific and Technical Information of China (English)

    Lei Juanmian; Zhao Shuai; Wang Suozhu

    2016-01-01

    This paper investigates the influence of forward-swept wing (FSW) positions on the aero-dynamic characteristics of aircraft under supersonic condition (Ma=1.5). The numerical method based on Reynolds-averaged Navier–Stokes (RANS) equations, Spalart–Allmaras (S–A) turbu-lence model and implicit algorithm is utilized to simulate the flow field of the aircraft. The aerody-namic parameters and flow field structures of the horizontal tail and the whole aircraft are presented. The results demonstrate that the spanwise flow of FSW flows from the wingtip to the wing root, generating an upper wing surface vortex and a trailing edge vortex nearby the wing root. The vortexes generated by FSW have a strong downwash effect on the tail. The lower the vertical position of FSW, the stronger the downwash effect on tail. Therefore, the effective angle of attack of tail becomes smaller. In addition, the lift coefficient, drag coefficient and lift–drag ratio of tail decrease, and the center of pressure of tail moves backward gradually. For the whole aircraft, the lower the vertical position of FSW, the smaller lift, drag and center of pressure coefficients of aircraft. The closer the FSW moves towards tail, the bigger pitching moment and center of pres-sure coefficients of the whole aircraft, but the lift and drag characteristics of the horizontal tail and the whole aircraft are basically unchanged. The results have potential application for the design of new concept aircraft.

  4. Synthesis and characterization of heteroleptic copper and zinc complexes with saccharinate and aminoacids. Evaluation of SOD-like activity of the copper complexes.

    Science.gov (United States)

    Santi, Eduardo; Viera, Inés; Mombrú, Alvaro; Castiglioni, Jorge; Baran, Enrique J; Torre, María H

    2011-12-01

    Five new copper and zinc heteroleptic complexes with saccharin and aminoacids with general stoichiometry Na(2)[M(sac)(2)(aa)(2)].nH(2)O (M denotes Cu or Zn, sac the saccharinate ion, and aa the aminoacids) were synthesized and characterized by elemental and thermogravimetric analysis, conductimetric measurements and IR, Raman and UV-vis spectroscopies. In all the complexes, copper and zinc ions coordinated with the aminoacids through the terminal amine and carboxylate residues and with saccharin through the heterocyclic nitrogen atom. Besides, the superoxide dismutase-like activity of the heteroleptic copper complexes was evaluated and compared with the homoleptic copper amino acid complexes with the aim to observe the influence of the saccharin coordination.

  5. Copper binding ligands: production by marine plankton and characterization by ESI-MS

    Science.gov (United States)

    Orians, K.; Ross, A.; Lawrence, M.; Ikonomou, M.

    2003-04-01

    Organic complexation affects the bioavailability and distribution of copper in the surface ocean. The cyanobacterium Synechococcus sp. PCC 7002 was cultured in the lab and subjected to near-toxic Cu concentrations. Strong Cu-binding ligands were produced under these conditions, as found for other species of Synechococcus. The copper-binding ligand produced had a log K'cond. (log conditional stability constant) of 12.2, similar to the natural ligands found in the surface ocean. The amount of ligand produced was proportional to the amount of copper present. Isolation and concentration of these compounds for characterization by electrospray mass spectrometry (ESI-MS) provides information about the structure of the organic ligands and their metal-ion complexes. Using model ligands, we'll show that ligands can be characterized by ESI-MS and that the location of the copper binding site can be determined in complex molecules. We'll also present results of copper-complexing ligands extracted from the coastal waters of British Columbia. Ligand concentrations are higher at low salinity and in surface waters, indicating that these ligands are produced in surface waters and/or delivered to the region via the Fraser River. Analysis of the extracts with highest UV absorbance identified two Cu2+ ligands of molecular weight 259 and 264. The mass and isotopic distributions are consistent with dipeptides and tripeptides containing two metal-binding amino groups. This result is consistent with the findings of other studies attempting to characterize Cu2+ ligands in seawater. The structure of the identified ligand is similar to that of rhodotorulic acid (a microbial siderophore), glutathione, and phytochelatins, indicating that small peptides and related compounds can act as strong, specific metal chelators in natural waters

  6. Synthesis, characterization and pharmacological studies of copper complexes of flavone derivatives as potential anti-tuberculosis agents.

    Science.gov (United States)

    Joseph, J; Nagashri, K; Suman, A

    2016-09-01

    Novel series of different hydroxyflavone derivatives and their copper complexes were synthesized. They were characterized using analytical and spectral techniques. The superoxide dismutase (SOD) mimetic activity of the synthesized complexes demonstrated that copper complex of L(10) has promising SOD-mimetic activity than other ligands & complexes. The in vitro antimicrobial activities of the synthesized compounds were tested against the bacterial species and fungal species. The DNA binding properties of copper complexes were studied using cyclic voltametry and electronic absorption techniques. Anti-tuberculosis activity was also performed. The effective complexes was subjected to antimycobacterial activity using MABA method and summarized. The antimycobacterial activity of copper complexes have been evaluated and discussed.

  7. Copper removal by algal biomass: Biosorbents characterization and equilibrium modelling

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Vitor J.P. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: vilar@fe.up.pt; Botelho, Cidalia M.S. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: cbotelho@fe.up.pt; Pinheiro, Jose P.S.; Domingos, Rute F. [Centro de Biomedicina Molecular e Estrutural, Department of Chemistry and Biochemistry, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Boaventura, Rui A.R. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: bventura@fe.up.pt

    2009-04-30

    The general principles of Cu(II) binding to algal waste from agar extraction, composite material and algae Gelidium, and different modelling approaches, are discussed. FTIR analyses provided a detailed description of the possible binding groups present in the biosorbents, as carboxylic groups (D-glucuronic and pyruvic acids), hydroxyl groups (cellulose, agar and floridean starch) and sulfonate groups (sulphated galactans). Potentiometric acid-base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl, following the quasi-Gaussian affinity constant distribution suggested by Sips, which permitted to estimate the maximum amount of acid functional groups (0.36, 0.25 and 0.1 mmol g{sup -1}) and proton binding parameters (pK{sup '}{sub H}=5.0,5.3and4.4;m{sub H} = 0.43, 0.37, 0.33), respectively for algae Gelidium, algal waste and composite material. A non-ideal, semi-empirical, thermodynamically consistent (NICCA) isotherm fitted better the experimental ion binding data for different pH values and copper concentrations, considering only the acid functional groups, than the discrete model. Values of pK{sup '}{sub M} (3.2; 3.6 and 3.3), n{sub M} (0.98, 0.91, 1.0) and p (0.67, 0.53 and 0.43) were obtained, respectively for algae Gelidium, algal waste and composite material. NICCA model reflects the complex macromolecular systems that take part in biosorption considering the heterogeneity of the biosorbent, the competition between protons and metals ions to the binding sites and the stoichiometry for different ions.

  8. Copper removal by algal biomass: biosorbents characterization and equilibrium modelling.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Pinheiro, José P S; Domingos, Rute F; Boaventura, Rui A R

    2009-04-30

    The general principles of Cu(II) binding to algal waste from agar extraction, composite material and algae Gelidium, and different modelling approaches, are discussed. FTIR analyses provided a detailed description of the possible binding groups present in the biosorbents, as carboxylic groups (D-glucuronic and pyruvic acids), hydroxyl groups (cellulose, agar and floridean starch) and sulfonate groups (sulphated galactans). Potentiometric acid-base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl, following the quasi-Gaussian affinity constant distribution suggested by Sips, which permitted to estimate the maximum amount of acid functional groups (0.36, 0.25 and 0.1 mmol g(-1)) and proton binding parameters (pK(H)=5.0, 5.3 and 4.4; m(H)=0.43, 0.37, 0.33), respectively for algae Gelidium, algal waste and composite material. A non-ideal, semi-empirical, thermodynamically consistent (NICCA) isotherm fitted better the experimental ion binding data for different pH values and copper concentrations, considering only the acid functional groups, than the discrete model. Values of pK(M) (3.2; 3.6 and 3.3), n(M) (0.98, 0.91, 1.0) and p (0.67, 0.53 and 0.43) were obtained, respectively for algae Gelidium, algal waste and composite material. NICCA model reflects the complex macromolecular systems that take part in biosorption considering the heterogeneity of the biosorbent, the competition between protons and metals ions to the binding sites and the stoichiometry for different ions.

  9. Synthesis and characterization of copper zinc oxide nanoparticles obtained via metathesis process

    Science.gov (United States)

    Phoohinkong, Weerachon; Foophow, Tita; Pecharapa, Wisanu

    2017-09-01

    Copper-doped zinc oxide nanoparticles were successfully synthesized by grinding copper acetate and zinc acetate powder with different starting molar ratios in combined with sodium hydroxide. The effect of initial copper and zinc molar ratios on the product samples was investigated and discussed. Relevant ligand coordination type of reactant acetate salt precursors and product samples were investigated by Fourier transform infrared spectroscopy (FTIR). The particle shapes and surface morphologies were characterized by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Phase structures of prepared samples were studied by x-ray powder diffraction (XRD) and x-ray absorption near-edge spectroscopy (XANES) was applied to investigate the local structure of Cu and Zn environment atoms. The results demonstrate that the, particle size of as-synthesized products affected by copper concentration in the precursor trend to gradually decreases from nanorod shape with diameter around 50-100 nm to irregular particle structure around 5 nm associated with an increase in the concentration of copper in precursor. Moreover, it is noticed that shape and morphology of the products are strongly dependent on Cu:Zn ratios during the synthesis. Nanocrystallines Cu-doped ZnO by the substitution in Zn site with a high crystallization degree of hexagonal wurtzite structure were obtained. This synthesis technique is suggested as a potential effective technique for preparing copper zinc oxide nanoparticles with various atomic ratio in wide range of applications. Contribution at the 4th Southeast Asia Conference on Thermoelectrics 2016 (SACT 2016), 15-18 December 2016, Da Nang City, Vietnam.

  10. Influence of Friction Stir Welding (FSW on Mechanical and Corrosion Properties of AW-7020M and Aw-7020 Alloys

    Directory of Open Access Journals (Sweden)

    Dudzik Krzysztof

    2016-09-01

    Full Text Available Friction welding associated with mixing the weld material (FSW - Friction Stir Welding is an alternative to MIG and TIG welding techniques for Al-alloys. This paper presents experimental results obtained from static tension tests on specimens made of AW-7020M and AW-7020 alloys and their joints welded by using FSW method carried out on flat specimens, according to Polish standards : PN-EN ISO 4136:2011 and PN-EN ISO 6892-1:2010. Results of corrosion resistance tests are also presented. The tests were performed by using the electrochemical impedance spectroscopy (EIS. EIS measurement was conducted with the use of three-electrode system in a substitute sea water environment (3,5% NaCl - water solution. The impedance tests were carried out under corrosion potential. Voltage signal amplitude was equal to 10mV, and its frequency range - 100 kHz ÷ 0,1 Hz. Atlas 0531 EU&IA potentiostat was used for the tests. For the tested object an equivalent model was selected in the form of a substitute electric circuit. Results of the impedance spectroscopy tests are presented in the form of parameters which characterize corrosion process, as well as on Nyquist’s graphs together with the best-fit theoretical curve.

  11. Chemical and structural characterization of copper adsorbed on mosses (Bryophyta)

    Energy Technology Data Exchange (ETDEWEB)

    González, Aridane G., E-mail: aridaneglez@gmail.com [GET (Géosciences Environnement Toulouse) UMR 5563CNRS, 14 Avenue Edouard Belin, F-31400 Toulouse (France); Jimenez-Villacorta, Felix [Instituto de Ciencia de Materiales Madrid, CSIC, Cantoblanco, E-28049 Madrid (Spain); Beike, Anna K. [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg (Germany); State Museum of Natural History Stuttgart, Rosenstein 1, 70191 Stuttgart (Germany); Reski, Ralf [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg (Germany); BIOSS—Centre for Biological Signalling Studies, 79104 Freiburg (Germany); FRIAS—Freiburg Institute for Advanced Studies, 79104 Freiburg (Germany); Adamo, Paola [Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Naples (Italy); Pokrovsky, Oleg S. [GET (Géosciences Environnement Toulouse) UMR 5563CNRS, 14 Avenue Edouard Belin, F-31400 Toulouse (France); BIO-GEO-CLIM Laboratory, Tomsk State University, Tomsk (Russian Federation); Institute of Ecological Problems of the North, Russian Academy of Science, Arkhangelsk (Russian Federation)

    2016-05-05

    Highlights: • Cu{sup 2+} was adsorbed on four mosses used in moss-bag pollution monitoring technique. • Thermodynamic approach was used to model Cu speciation based on XAS results. • All studied mosses have ∼4.5 O/N atoms at ∼1.95 Å around Cu likely in a pseudo-square geometry. • Cu(II)-carboxylates and Cu(II)-phosphoryls are the main moss surface binding groups. • Moss growing in batch reactor yielded ∼20% of Cu(I) in the form of Cu–S(CN) complexes. - Abstract: The adsorption of copper on passive biomonitors (devitalized mosses Hypnum sp., Sphagnum denticulatum, Pseudoscleropodium purum and Brachythecium rutabulum) was studied under different experimental conditions such as a function of pH and Cu concentration in solution. Cu assimilation by living Physcomitrella patents was also investigated. Molecular structure of surface adsorbed and incorporated Cu was studied by X-ray Absorption Spectroscopy (XAS). Devitalized mosses exhibited the universal adsorption pattern of Cu as a function of pH, with a total binding sites number 0.05–0.06 mmolg{sub dry}{sup −1} and a maximal adsorption capacity of 0.93–1.25 mmolg{sub dry}{sup −1} for these devitalized species. The Extended X-ray Absorption Fine Structure (EXAFS) fit of the first neighbor demonstrated that for all studied mosses there are ∼4.5 O/N atoms around Cu at ∼1.95 Å likely in a pseudo-square geometry. The X-ray Absorption Near Edge Structure (XANES) analysis demonstrated that Cu(II)-cellulose (representing carboxylate groups) and Cu(II)-phosphate are the main moss surface binding moieties, and the percentage of these sites varies as a function of solution pH. P. patens exposed during one month to Cu{sup 2+} yielded ∼20% of Cu(I) in the form of Cu–S(CN) complexes, suggesting metabolically-controlled reduction of adsorbed and assimilated Cu{sup 2+}.

  12. Electrodeposition and Characterization of Nickel, Iron, Copper Thin Films and the Creation of Nanoporous Structures

    Science.gov (United States)

    Yarranton, Jonathan; Hampton, Jennifer

    2013-03-01

    There has been much research in creating nanoporous platinum or gold thin films for catalysis, but there has not been as much work done with other, less noble metals. This research explored the deposition of nickel, iron, and copper ternary alloys using controlled potential electrolysis (CPE) and the selective removal of the copper with DC potential amperometry (DCPA) and linear sweep voltammetry (LSV) to create nanoporous structures. These structures have the advantage of increased surface area creating more efficient catalysts. All films were characterized before and after dealloying using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) for composition. The roughness of each of the films was characterized by the capacitance of the film, with higher capacitances indicating a higher electrochemical surface area. This material is based upon work supported by the National Science Foundation under RUI Grant DMR-1104725, MRI Grant CHE-0959282, and ARI grant PHY-0963317.

  13. Synthesis and characterization of Eichhornia-mediated copper oxide nanoparticles and assessing their antifungal activity against plant pathogens

    Indian Academy of Sciences (India)

    P VANATHI; P RAJIV; RAJESHWARI SIVARAJ

    2016-09-01

    In this paper, we report the biosynthesis and characterization of copper oxide nanoparticles from an aquatic noxious weed, Eichhornia crassipes by green chemistry approach. The aim of this work is to synthesize copper oxide nanoparticles by simple, cost-effective and ecofriendly method as an alternative to other available techniques. 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 with an average diameter of $28\\pm 4$ nm. The synthesized nanoparticles were then explored to antifungal activity against plant pathogens. Highest zone of inhibition were observed in 100 $\\mu$g ml$^{−1}$ of Eichhornia-mediated copper oxide nanoparticle against Fusarium culmorum and Aspergillus niger. This Eichhornia-mediated copper oxide nanoparticles wereproved to be good antifungal agents against plant fungal pathogens.

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

    Directory of Open Access Journals (Sweden)

    Evarice Yama Nzoma

    2012-01-01

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

  15. Aluminum/Copper Oxide/Copper Memristive Devices: Fabrication, Characterization, and Modeling

    Science.gov (United States)

    McDonald, Nathan R.

    Memristive devices have become very popular in recent years due to their potential to dramatically alter logic processing in CMOS circuitry. Memristive devices function as electrical potentiometers, allowing for such diverse applications as memory storage, multi-state logic, and reconfigurable logic gates. This research covered the fabrication, characterization, and modeling of Al/CuxO/Cu memristive devices created by depositing Al top electrodes atop a CuxO film grown using plasma oxidation to grow the oxide on a Cu wafer. Power settings of the plasma oxidation system were shown to control the grown oxide thickness and oxygen concentration, which subsequently affected memristive device behaviors. These memristive devices demonstrated complete nonpolar behavior and could be switched either in a vertical (Al/Cu xO/Cu) or lateral (Al/CuxO/Cu/CuxO/Al) manner. The switching mechanism of these devices was shown to be filamentary in nature. Physical and empirical models of these devices were created for MATLAB, HSPICE, & Verilog A environments. While the physical model proved of limited practical consequence, the robust empirical model allows for rapid prototyping of CMOS-memristor circuitry.

  16. Paintings on copper by the Flemish artist Frans Francken II: PIXE characterization by external microbeam

    Science.gov (United States)

    Corregidor, V.; Oliveira, A. R.; Rodrigues, P. A.; Alves, L. C.

    2015-04-01

    Resorting to an external proton microbeam, PIXE analyses of three oil paintings on copper support dated from the XVII century and attributed to the Flemish artist Frans Francken II, were undertaken. The present work aims to contribute to the compositional study of the painting materials employed by XVII century artists that exploited copper as a support for oil painting, and specifically the materials used by Francken's workshop, particularly copper plates. Because of the low thickness of the pictorial layers of this type of paintings and its non-destructive character, PIXE is the ideal technique to study the elemental composition of the paintings. Several spots in each painting were chosen for analysis in order to cover almost all the pigments used in the colour palette. Lead and calcium were detected in practically every analysed regions, probably related to the presence of lead white and chalk, usually used as ground layer on copper paintings. Small quantities of gold were also detected, which is present in many of this artist's works to embellish some details of the representations. Also this work reports the first application of the external proton microbeam set-up available at CTN/IST in Portugal for the characterization of oil paintings.

  17. Synthesis and Structural Characterization of a Copper Complex with Furaldehyde Salicylylhydrazone

    Institute of Scientific and Technical Information of China (English)

    DU Kang-Kai; LIU Shi-Xiong

    2008-01-01

    The copper complex Cu(C12H9N2O3)2 has been synthesized by the reaction of furaldehyde salicylylhydrazone (Hfs) and copper acetylacetonate and characterized by X-ray crystal diffraction and spectroscopic studies. The crystal crystallizes in space group P21/n with a =5.9765(3), b = 15.7196(9), c = 12.0514(6) A, β= 101.618(3)°,V= 1109.0(1) A3,C24H18CuN4O6,M, = 521.96, Z= 2, Dc = 1.563 g/cm3, μ =1.035 mm-1,F(000) = 534, R = 0.0373 and wR =0.1058 for 2283 observed reflections (Ⅰ 20(Ⅰ)). The copper atom has a square-planar CuN2O2 coordination and should be in an oetahedral coordination if considering Cu-O (phenol) with distances of 2.796(2) A as weak bonds. The neighboring copper complex molecules are linked together by these weak Cu-O (phenol) bonds, resulting in an extended 1D chain. The title com-pound exhibits paramagnetie property and fluorescence behavior at room temperature supported by the EPR and fluorescence spectra.

  18. Paintings on copper by the Flemish artist Frans Francken II: PIXE characterization by external microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Corregidor, V., E-mail: vicky.corregidor@ctn.ist.utl.pt [IPFN, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Universidade de Lisboa, E.N. 10, 2695-066 Sacavém (Portugal); Oliveira, A.R. [CCR-Centro de Conservação e Restauro, R. do Ginjal, 11, 2950-685 Palmela (Portugal); Rodrigues, P.A. [LATR, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Universidade de Lisboa, E.N. 10, 2695-066 Sacavém (Portugal); Alves, L.C. [C2TN, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Universidade de Lisboa, E.N. 10, 2695-066 Sacavém (Portugal)

    2015-04-01

    Resorting to an external proton microbeam, PIXE analyses of three oil paintings on copper support dated from the XVII century and attributed to the Flemish artist Frans Francken II, were undertaken. The present work aims to contribute to the compositional study of the painting materials employed by XVII century artists that exploited copper as a support for oil painting, and specifically the materials used by Francken’s workshop, particularly copper plates. Because of the low thickness of the pictorial layers of this type of paintings and its non-destructive character, PIXE is the ideal technique to study the elemental composition of the paintings. Several spots in each painting were chosen for analysis in order to cover almost all the pigments used in the colour palette. Lead and calcium were detected in practically every analysed regions, probably related to the presence of lead white and chalk, usually used as ground layer on copper paintings. Small quantities of gold were also detected, which is present in many of this artist’s works to embellish some details of the representations. Also this work reports the first application of the external proton microbeam set-up available at CTN/IST in Portugal for the characterization of oil paintings.

  19. Physicochemical characterization of functionalized-nanostructured-titania as a carrier of copper complexes for cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    López, Tessy [Nanotechnology and Nanomedicine Laboratory, Metropolitan Autonomous University-Xochimilco, Calzada del Hueso 1100, Villa Quietud, Coyoacán, 04960 México D.F. (Mexico); Nanotechnology Laboratory, National Institute of Neurology and Neurosurgery “MVS”, Avenida Insurgentes Sur 3877, La Fama, Tlalpan, 14269 México D.F. (Mexico); Department of Chemical and Biomolecular Engineering, Tulane University, 6823 St. Charles Avenue, New Orleans (United States); Ortiz, Emma, E-mail: emma170@hotmail.com [Nanotechnology Laboratory, National Institute of Neurology and Neurosurgery “MVS”, Avenida Insurgentes Sur 3877, La Fama, Tlalpan, 14269 México D.F. (Mexico); Guevara, Patricia [Neuroimmunology Laboratory, National Institute of Neurology and Neurosurgery “MVS”, Insurgentes Sur 3877, La Fama, Tlalpan, 14269 México D.F. (Mexico); Gómez, Esteban [Nanotechnology Laboratory, National Institute of Neurology and Neurosurgery “MVS”, Avenida Insurgentes Sur 3877, La Fama, Tlalpan, 14269 México D.F. (Mexico); Novaro, Octavio [Institute of Physics-UNAM, Circuito de la Investigación Científica Ciudad Universitaria, CP 04510 México D.F. (Mexico)

    2014-07-01

    In the present paper we report the preparation and characterization of functionalized-TiO{sub 2} (F-TiO{sub 2}) to obtain a biocompatible material to be used as carrier of alternative anticancer agents: copper acetate and copper acetylacetonate. The sol–gel procedure was used to prepare the fuctionalized titania material through hydrolysis and condensation of the titanium's butoxide. Sulfate, amine and phosphate ions served as functional groups which were anchored to the titania's surface. Mineral acids and gamma amine butyric acid were the precursors and they were added at the initial step of the synthesis. The copper complexes were loaded on titania and were also added to the reactor synthesis from the beginning. Infrared and ultraviolet–visible spectroscopies were the principal techniques used to the characterization of F-TiO{sub 2} and copper complexes loaded on titania materials. Transmission Electronic Microscopy (TEM) was used to complement the characterization's studies. The biocompatibility of F-TiO{sub 2} was evaluated by treating different cancer cell lines with increased concentration of this compound. The amine, the sulfate and the phosphate on the titania's surface, as well as the integral structures of the metal complexes on titania were well identified by infrared and ultraviolet–visible spectroscopies. The TEM photographs of Cu(acac){sub 2}/F-TiO{sub 2} and Cu(Oac){sub 2}/F-TiO{sub 2} materials showed the formation of nanoparticles, which have sizes ranging from 4 to 10 nm, with no morphology alterations in comparison with F-TiO{sub 2} nanoparticles, suggesting that the presence of low quantities of copper do not affect the structure of the nanoparticles. The Energy Dispersive Spectroscopy (EDS) confirms the presence of copper on the titania's nanoparticles. The biological results indicate that there is more than 90% cell survival, thus suggesting that F-TiO{sub 2} does not cause damage to the cells. Therefore

  20. Final report on characterization of physical and mechanical properties of copper and copper alloys before and after irradiation

    DEFF Research Database (Denmark)

    Singh, B.N.; Tähtinen, S.

    2002-01-01

    The present report summarizes and highlights the main results of the work carried out during the last 5-6 years on effects of neutron irradiation on physical and mechanical properties of copper and copper alloys. The work was an European contribution toITER Research and Development programme...... amount of further effort is needed to find a realistic and optimum solution....

  1. Spectroscopic characterization of copper(I) binding to apo and metal-reconstituted zinc finger peptides.

    Science.gov (United States)

    Doku, Reginald T; Park, Grace; Wheeler, Korin E; Splan, Kathryn E

    2013-08-01

    Cu(I) exhibits high affinity for thiolate ligands, suggesting that thiol-rich zinc or iron binding sites may be subject to disruption during copper stress conditions. Zinc fingers constitute a large class of metalloproteins that use a combination of cysteine and histidine residues that bind Zn(II) as a structural element. Despite the shared preference of both copper and zinc for thiolate and amine coordination, the susceptibility of zinc finger domains toward copper substitution is not well studied. We report spectroscopic studies that characterize the Cu(I) binding properties of the zinc finger consensus peptides CP-CCHH, CP-CCHC, and CP-CCCC and the C-terminal zinc finger domain of HIV-1 nucleocapsid protein p7 (NCp7_C). Cu(I) binds to both the apopeptides and the Co(II)-substituted peptides, and the stoichiometry of Cu(I) binding is dependent on the number of cysteine thiols at the metal binding site. Fluorescence studies of the Zn(II)-NCp7_C complex indicate that Cu(I) also effectively competes with Zn(II) at the metal binding site, despite the high affinity of Zn(II) for the CCHC binding motif. Circular dichroism studies on both CP-CCHC and NCp7_C show that the conformations of the Cu(I)-bound complexes differ substantially from those of the Zn(II) species, implying that Cu(I) substitution is likely to impact zinc finger function. These results show that for the peptides studied here, Cu(I) is the thermodynamically favored metal despite the known high Zn(II) affinity of zinc finger domains, suggesting that Cu(I)-substituted zinc finger domains might be relevant in the context of both copper toxicity mechanisms and copper-responsive transcription factors.

  2. Characterization of pure and copper-doped iron tartrate crystals grown in silica gel

    Indian Academy of Sciences (India)

    V Mathivanan; M Haris

    2013-07-01

    Single crystal growth of pure and copper-doped iron tartrate crystals bearing composition Cu Fe(1−) C4H4O6 · H2O, where = 0, 0.07, 0.06, 0.05, 0.04, 0.03, is achieved using gel technique. The elemental analysis has been done using energy-dispersive X-ray analysis (EDAX) spectrum. The characterization studies such as Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), magnetic analysis and thermal analysis have been done for crystals with = 0 for pure iron tartrate and with = 0.05 for copper-mixed iron tartrate crystals. A detailed comparison has been made between pure and doped crystals.

  3. Synthesis and Characterization of Bovine Serum Albumin-Conjugated Copper Sulfide Nanocomposites

    Directory of Open Access Journals (Sweden)

    Peng Huang

    2010-01-01

    Full Text Available A simple biomolecule-assisted solution route was developed to synthesize Bovine Serum Albumin-conjugated copper sulfide (CuS/BSA nanocomposites, directly using copper salts and thioacetamide (TAA as the starting materials with a zwitterionic surfactant Bovine Serum Albumin (BSA as foaming and stabilizing agent. The CuS/BSA nanocomposites have been characterized by UV, TEM, Zeta, DLS, XRD, and FTIR. The results indicate that the as-prepared CuS/BSA nanocomposites are approximate sphere with a size distribution from 10 to 35 nm in diameter and good dispersibility, depending highly on concentration of BSA concentration. These protein-assisted synthesized nanocomposites have a great potential application in biomedical engineering and microelectronics.

  4. Analytical characterization of laser-generated copper nanoparticles for antibacterial composite food packaging.

    Science.gov (United States)

    Longano, D; Ditaranto, N; Cioffi, N; Di Niso, F; Sibillano, T; Ancona, A; Conte, A; Del Nobile, M A; Sabbatini, L; Torsi, L

    2012-05-01

    A new type of nanomaterial has been developed as antibacterial additive for food packaging applications. This nanocomposite is composed of copper nanoparticles embedded in polylactic acid, combining the antibacterial properties of copper nanoparticles with the biodegradability of the polymer matrix. Metal nanoparticles have been synthesised by means of laser ablation, a rising and easy route to prepare nanostructures without any capping agent in a liquid environment. As prepared, nanoparticle suspensions have been easily mixed to a polymer solution. The resulting hybrid solutions have been deposited by drop casting, thus obtaining self-standing antibacterial packages. All samples have been characterized by UV-Vis spectroscopy, X-ray photoelectron spectroscopy and electro-thermal atomic absorption spectroscopy. Ion release data have been matched with bioactivity tests performed by Japanese Industrial Standard (JIS) method (JIS Z 2801:2000) against Pseudomonas spp., a very common Gram-negative microbial group able to proliferate in processed food.

  5. Isolation, Characterization and Antitumour Propirties of the 1,2-Popylenediaminetetraacetate trans-Diaqua-Copper (II).

    Science.gov (United States)

    Kamah, S; Vilaplana, R; Moreno, J; Akdi, K; García-Herdugo, G; González-Vílchez, F

    2000-01-01

    A trans-diaquacomplex formed by copper(II) sulphate and the sequestering polyamminopolycarboxylic ligand 1,2-propylenediaminetetraacetic acid (PDTA) has been isolated and characterized by chemical analysis, titrimetry, FT-IR and electronic spectroscopy, Potentiometric and electronic measurements identified the ligand as tetradentate, two nitrogen and two oxygen atoms being bonded to the Cu(II) in planar positions. This octahedral monomeric soluble compound, is an unusual example of a copper (II) substance showing significant in vitro antitumour activity against the human ovarian tumour cells TG (ID(50) = 2.29 muM at 48 h) and important in vivo antitumour activity against solid Sarcoma 180 with complete regression of the tumour at a dose of 12.5 mg/Kg body weight.

  6. Synthesis, structural characterization and biological studies of copper complexes with 2-aminobenzothiazole derivatives

    Science.gov (United States)

    Joseph, J.; Boomadevi Janaki, G.

    2014-04-01

    Novel copper complexes of 2-aminobenzothiazole derivatives were synthesized by the condensation of Knoevenagel condensate acetoacetanilide (obtained from substituted benzaldehydes and acetoacetanilide) and 2-aminobenzothiazole. They were thoroughly characterized by elemental analysis, IR, 1H NMR, UV-Vis., MS Spectra, molar conductance, magnetic moment and electrochemical studies. These spectral studies suggested that distorted square planar geometry for all the complexes. Molar conductance data and magnetic susceptibility measurements provide evidence for monomeric and neutral nature of the complexes. The electrochemical behaviour of the ligand and complexes in DMSO at 298 K was studied. The present ligand systems stabilize the unusual oxidation states of copper ion during electrolysis. Antibacterial screening of the ligands and their complexes reveal that all the complexes show higher activities than the free ligands.

  7. Characterization of the Nanoscale Microstructure of an Immersion Silver on Sputtered Copper

    Institute of Scientific and Technical Information of China (English)

    TANG Dian; WEI Zhe-Liang; SHAO Yan-Qun; YOU Shao-Xin; O'KEEFE Mathew; O'KEEFE Thomas

    2005-01-01

    Silver has grown its attraction of the scientists in microelectronic field recently.Electrochemical deposition of silver onto copper substrates by immersion method has been one of the keen topics.In this study, ethanol was used as the plating solution in which some chemicals were added.The silver deposits were characterized by a field emission scanning electron microscopy (FESEM), an atom force microscope (AFM), a transmission electron microscope (TEM) and a selected area electron diffraction (SAED).It was found that silver immersion using ethanol-based bath has good coverage feature.The highlands of the copper substrate are coated by silver particles whose sizes are around 12 nm, but those sizes at low-lying lands are a little smaller.

  8. Isolation and characterization of lost copper and molybdenum particles in the flotation tailings of Kennecott copper porphyry ores

    Science.gov (United States)

    Tserendavga, Tsend-Ayush

    The importance of flotation separation has long been, and continues to be, an important technology for the mining industry, especially to metallurgical engineers. However, the flotation process is quite complex and expensive, in addition to being influenced by many variables. Understanding the variables affecting flotation efficiency and how valuable minerals are lost to the tailings gives metallurgists an advantage in their attempts to increase efficiency by designing operations to target the areas of greatest potential value. A successful, accurate evaluation of lost minerals in the tailings and appropriate solutions to improve flotation efficiency can save millions of dollars in the effective utilization of our mineral resources. In this dissertation research, an attempt has been made to understand the reasons for the loss of valuable mineral particles in the tailings from Kennecott Utah Copper ores. Possibilities include liberation, particle aggregation (slime coating) and surface chemistry issues associated with the flotation separation. This research generally consisted of three main aspects. The first part involved laboratory flotation experiments and factors, which affect the flotation efficiency. Results of flotation testing are reported that several factors such as mineral exposure/liberation and slime coating and surface oxidation strongly affect the flotation efficiency. The second part of this dissertation research was to develop a rapid scan dual energy (DE) methodology using 2D radiography to identify, isolate, and prepare lost sulfide mineral particles with the advantages of simple sample preparation, short analysis time, statistically reliable accuracy and confident identification. The third part of this dissertation research was concerned with detailed characterization of lost particles including such factors as liberation, slime coating, and surface chemistry characteristics using advanced analytical techniques and instruments. Based on the

  9. Biosynthesis and characterization of Acalypha indica mediated copper oxide nanoparticles and evaluation of its antimicrobial and anticancer activity

    Science.gov (United States)

    Sivaraj, Rajeshwari; Rahman, Pattanathu K. S. M.; Rajiv, P.; Narendhran, S.; Venckatesh, R.

    2014-08-01

    Copper oxide nanoparticles were synthesized by biological method using aqueous extract of Acalypha indica leaf and characterized by UV-visible spectroscopy, XRD, FT-IR, SEM TEM and EDX analysis. The synthesised particles were highly stable, spherical and particle size was in the range of 26-30 nm. The antimicrobial activity of A.indica mediated copper oxide nanoparticles was tested against selected pathogens. Copper oxide nanoparticles showed efficient antibacterial and antifungal effect against Escherichia coli, Pseudomonas fluorescens and Candida albicans. The cytotoxicity activity of A.indica mediated copper nanoparticles was evaluated by MTT assay against MCF-7 breast cancer cell lines and confirmed that copper oxide nanoparticles have cytotoxicity activity.

  10. Biosynthesis and characterization of Acalypha indica mediated copper oxide nanoparticles and evaluation of its antimicrobial and anticancer activity.

    Science.gov (United States)

    Sivaraj, Rajeshwari; Rahman, Pattanathu K S M; Rajiv, P; Narendhran, S; Venckatesh, R

    2014-08-14

    Copper oxide nanoparticles were synthesized by biological method using aqueous extract of Acalypha indica leaf and characterized by UV-visible spectroscopy, XRD, FT-IR, SEM TEM and EDX analysis. The synthesised particles were highly stable, spherical and particle size was in the range of 26-30 nm. The antimicrobial activity of A.indica mediated copper oxide nanoparticles was tested against selected pathogens. Copper oxide nanoparticles showed efficient antibacterial and antifungal effect against Escherichia coli, Pseudomonas fluorescens and Candida albicans. The cytotoxicity activity of A.indica mediated copper nanoparticles was evaluated by MTT assay against MCF-7 breast cancer cell lines and confirmed that copper oxide nanoparticles have cytotoxicity activity.

  11. 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.

  12. XPS and GDOES Characterization of Porous Coating Enriched with Copper and Calcium Obtained on Tantalum via Plasma Electrolytic Oxidation

    Directory of Open Access Journals (Sweden)

    Krzysztof Rokosz

    2016-01-01

    Full Text Available XPS and GDOES characterizations of porous coatings on tantalum after Plasma Electrolytic Oxidation (PEO at 450 V for 3 minutes in electrolyte containing concentrated (85% phosphoric acid with calcium nitrate and copper (II nitrate are described. Based on the obtained data, it may be concluded that the PEO coating consists of tantalum (Ta5+, calcium (Ca2+, copper (Cu2+  and Cu+, and phosphates (PO43-. It has to be pointed out that copper and calcium are distributed throughout the volume. The authors also propose a new model of PEO, based on the derivative of GDOES signals with sputtering time.

  13. An investigation of the synthesis and characterization of copper samples for use in interconnect applications

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, M. [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore)], E-mail: mpegm@nus.edu.sg; Tay, A.A.O. [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Vaidyanathan, K. [Institute of Microelectronics, 11, Science Park Road, Singapore 117685 (Singapore); Srivatsan, T.S. [Department of Mechanical Engineering, University of Akron, Akron, OH 44325 (United States)

    2007-04-25

    In this study nanostructured (grain size: 81 {+-} 31 nm) micron-sized pure copper powder was compacted in a die using a uniaxial force at room temperature and at pressures ranging from 0.25 to 1.00 GPa. The pressure range selected was based on an ability of the silicon wafer to withstand the pressure without experiencing mechanical damage. The as-compacted copper compacts were sintered at 200 deg. C for 2 h in an atmosphere of argon. The purpose of this research study was to optimize the compaction pressure to get properties in the compacted copper sample that makes it suitable for use as an electronic packaging material. The characterization studies revealed that an increase in compaction pressure followed by sintering at a low temperature had a minimal to no influence on grain size but a noticeable influence on both porosity and hardness of the compacted sample. The microhardness of the as-compacted samples was found to be superior to the values obtained for the samples synthesized using the techniques of inert gas deposition and in situ compaction, solution phase synthesis, and plasma pressure compaction. The influence of compaction pressure on hardness of the sintered samples is rationalized in light of its intrinsic influence on microstructural development and processing-related artifacts.

  14. Synthesis, Characterization and Magnetic Studies of μ-Oxamido Copper(Ⅱ) -Chromium (Ⅲ) Heterodinuclear Complexes

    Institute of Scientific and Technical Information of China (English)

    李延团; 胡春霞; 焉翠蔚; 廖代正

    2001-01-01

    Three new μ-oxamido-bridged heterodinuclear copper (Ⅱ)-chromium(Ⅲ) complexes formulated[Cu(Me2 oxpn)Cr(L)2](NO3)3, where Me2 oxpn denotes N, N'-bis(3-amino-2,2-dimethylpropyl)oxamido dianion and L represents 5-methy1, 10-phenanthroline(Mephen), 4, 7-diphenl-1, 10-phenanthroline (Ph2phen) or 2,2'-bipyridine(bpy), have ben synthesized and characterized by elemental analyses,IR and electronic spectral studies, magnetic moments of room-temperature and molar conductivity measurements.It is proposed that these complexes have oxamido-bridged structures consisting of planar copper(Ⅱ) and octahedral chromium(Ⅲ) ions. The variable temperature magnetic susceptibilities (4.2-300 K)of complexes [Cu(Me2 oxpn)Cr(Ph2phen)2](NO3)3 (1) and [Cu(Me2 ocpn)Cr(Mephen)2] (NO3)3 (2) were further measured and studied, demonstrating the ferromagnetic interaction between the adjacent chromium(Ⅲ)and copper(Ⅱ)ions through the oxamido-bridge in both camplexes 1 and 2.Based on the spin Hamiltonian, H= -2JS1.S2, the exclange integrals J were evaluated as +21.5 cm-1 for 1 and +22.8 cm-1 for 2.

  15. Tribological, Thermal, and Kinetic Characterization of 300-mm Copper Chemical Mechanical Planarization Process

    Science.gov (United States)

    Jiao, Yubo; Adi Sampurno, Yasa; Zhuang, Yun; Wei, Xiaomin; Meled, Anand; Philipossian, Ara

    2011-05-01

    In this study, the tribological, thermal, and kinetic attributes of 300-mm copper chemical mechanical planarization were characterized for two different pads. The coefficient of friction (COF) ranged from 0.39 to 0.59 for the D100 pad, indicating that boundary lubrication was the dominant tribological mechanism. In comparison, COF decreased sharply from 0.55 to 0.03 for the IC1000 pad, indicating that the tribological mechanism transitioned rapidly from boundary lubrication to partial lubrication. Consequently, the D100 pad exhibited higher pad temperatures and removal rates than the IC1000 pad. A two-step modified Langmuir-Hinshelwood model was used to simulate copper removal rates as well as chemical and mechanical rate constants. The simulated copper removal rates agreed very well with experimental data and the model successfully captured the non-Prestonian behavior. The simulated chemical rate to mechanical rate constant ratios indicated that the IC1000 pad generally produced a more mechanically controlled removal mechanism than the D100 pad.

  16. Characterization of copper transport in gill cells of a mangrove crab Ucides cordatus

    Energy Technology Data Exchange (ETDEWEB)

    Sá, M.G. [Biosciences Institute, Department of Physiology, University of São Paulo, Rua do Matão, Travessa 14, 101, São Paulo 05508-900, SP (Brazil); Zanotto, F.P., E-mail: fzanotto@usp.br [Biosciences Institute, Department of Physiology, University of São Paulo, Rua do Matão, Travessa 14, 101, São Paulo 05508-900, SP (Brazil); Department of Biophysics, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Rua Três de Maio 100, Sao Paulo 04044-020 (Brazil)

    2013-11-15

    Highlights: •Copper transport in gill cells of a mangrove crab Ucides cordatus is dependent of calcium. •Copper transport mechanism is ATP-dependent. •Transport was monitored second by second during 300 s. -- Abstract: The branchial epithelium of crustaceans is exposed to the environment and is the first site affected by metal pollution. The aim of this work was to characterize copper (Cu) transport using a fluorescent dye, Phen Green, in gill cells of a hypo-hyper-regulator mangrove crab Ucides cordatus. The results showed that added extracellular CuCl{sub 2} (0, 0.025, 0.150, 0.275, 0.550 and 1.110 μM) showed typical Michaelis–Menten transport for Cu in anterior and posterior gill cells (V{sub max} for anterior and posterior gills: 0.41 ± 0.12 and 1.76 ± 0.27 intracellular Cu in μM × 22.10{sup 4} cells{sup −1} × 300 s{sup −1} respectively and K{sub m} values: 0.44 ± 0.04 and 0.32 ± 0.13 μM, respectively). Intracellular Cu was significantly higher for posterior gill cells compared to anterior gill cells, suggesting differential accumulation for each gill type. Extracellular Ca at 20 mM decreased cellular Cu transport for both anterior and posterior gill cells. Nifedipine and verapamil, calcium channel inhibitors from plasma membrane, decreased Cu transport and affected K{sub m} for both gills. These results could be due to a competition between Cu and Ca. Amiloride, a Na/Ca exchanger inhibitor, as well as bafilomycin, a proton pump inhibitor, caused a decrease of intracellular Cu compared to control. Ouabain and KB-R 7943, acting on Na homeostasis, similarly decreased intracellular Cu in both gill cells. Besides that, gill cells exposed to ATP and Cu simultaneously, showed an increase in intracellular copper, which was inhibited by vanadate, an inhibitor of P-type ATPase. These results suggest either the presence of a Cu-ATPase in crab gill cells, responsible for Cu influx, or the effect of a change in electrochemical membrane potential that

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

    Science.gov (United States)

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

    2004-11-01

    A low-cost chemical bath deposition (CBD) technique has been used for the preparation of Cu2-xSe thin films onto glass substrates and deposited films were characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and UV-vis spectrophotometry. Good quality thin films of smooth surface of copper selenide thin films were deposited using sodium selenosulfate as a source of selenide ions. The structural and optical behaviour of the films are discussed in the light of the observed data.

  18. Magnetotelluric survey to characterize the Sunnyside porphyry copper system in the Patagonia Mountains, Arizona

    Science.gov (United States)

    Rodriguez, Brian D.; Sampson, Jay A.

    2010-01-01

    The Sunnyside porphyry copper system is part of the concealed San Rafael Valley porphyry system located in the Patagonia Mountains of Arizona. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. To help characterize the size and resistivity of the mineralized area beneath overburden, a regional east-west magnetotelluric sounding profile was acquired. This is a data release report of the magnetotelluric sounding data collected along the east-west profile; no interpretation of the data is included.

  19. Audio-magnetotelluric survey to characterize the Sunnyside porphyry copper system in the Patagonia Mountains, Arizona

    Science.gov (United States)

    Sampson, Jay A.; Rodriguez, Brian D.

    2010-01-01

    The Sunnyside porphyry copper system is part of the concealed San Rafael Valley porphyry system located in the Patagonia Mountains of Arizona. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. To help characterize the size, resistivity, and skin depth of the polarizable mineral deposit concealed beneath thick overburden, a regional east-west audio-magnetotelluric sounding profile was acquired. The purpose of this report is to release the audio-magnetotelluric sounding data collected along that east-west profile. No interpretation of the data is included.

  20. Synthesis and characterization of manganese-glycine and copper-glycine adducts

    Directory of Open Access Journals (Sweden)

    Robson Fernandes de Farias

    2002-09-01

    Full Text Available This work reports the synthesis and characterization of adducts of general formula MCl2.ngly, where M= Mn and Cu; n= 2 and 4, and gly= glycine. The manganese adducts were synthesized by dissolution of both, manganese chloride and glycine in water, whereas the copper adducts were obtained by using an alternative solid state synthesis approach. For all adducts, the obtained infrared data shows that the coordination involves the amine nitrogen atom, as well as an oxygen atom of the COO- group. The TG curves for the synthesized adducts exhibit only one mass loss step associated with the release of glycine molecules.

  1. [Structural characterization of copper-phthalocyanine thin solid films by FTIR spectroscopy].

    Science.gov (United States)

    Ding, H; Zhang, Y; Chen, W; Xi, S

    1997-04-01

    The structure of tris- (2, 4-di-t-amylpheoxy) - (8-quinolinoxy) copper phthalocyanine (CuPc) thin solid films has been characterized by Fourier transform infrared (FTIR) transmission, polarized transmission and reflection absorption (RA) spectroscopy. The following conclusions can be obtained from the above measurements: (1)in LB films, the hydrocarbon chains of CuPc are in hexagonal or pseudohexagonal subcell packing, the CH2 asymmetric vibrational vector is oriented with respect to the substrate surface and the RA spectroscopy can distinguish the two CH2 streching modes of benzene cycle; (2)in sublimed films, the molecules of CuPc are out of order.

  2. 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 the orientation distribution function of each individual grain is analyzed. Extent and shape of the disorientation distribution in orientation space are quantified by the tensor of the second-order central moments, its principal values and directions. The latter characterize the main rotation axes...

  3. Fatigue Strength Estimation Based on Local Mechanical Properties for Aluminum Alloy FSW Joints

    Directory of Open Access Journals (Sweden)

    Kittima Sillapasa

    2017-02-01

    Full Text Available Overall fatigue strengths and hardness distributions of the aluminum alloy similar and dissimilar friction stir welding (FSW joints were determined. The local fatigue strengths as well as local tensile strengths were also obtained by using small round bar specimens extracted from specific locations, such as the stir zone, heat affected zone, and base metal. It was found from the results that fatigue fracture of the FSW joint plate specimen occurred at the location of the lowest local fatigue strength as well as the lowest hardness, regardless of microstructural evolution. To estimate the fatigue strengths of aluminum alloy FSW joints from the hardness measurements, the relationship between fatigue strength and hardness for aluminum alloys was investigated based on the present experimental results and the available wide range of data from the references. It was found as: σa (R = −1 = 1.68 HV (σa is in MPa and HV has no unit. It was also confirmed that the estimated fatigue strengths were in good agreement with the experimental results for aluminum alloy FSW joints.

  4. Emission of nanoparticles during friction stir welding (FSW) of aluminium alloys.

    Science.gov (United States)

    Gomes, J F; Miranda, R M; Santos, T J; Carvalho, P A

    2014-01-01

    Friction stir welding (FSW) is now well established as a welding process capable of joining some different types of metallic materials, as it was (1) found to be a reliable and economical way of producing high quality welds, and (2) considered a "clean" welding process that does not involve fusion of metal, as is the case with other traditional welding processes. The aim of this study was to determine whether the emission of particles during FSW in the nanorange of the most commonly used aluminum (Al) alloys, AA 5083 and AA 6082, originated from the Al alloy itself due to friction of the welding tool against the item that was being welded. Another goal was to measure Al alloys in the alveolar deposited surface area during FSW. Nanoparticles dimensions were predominantly in the 40- and 70-nm range. This study demonstrated that microparticles were also emitted during FSW but due to tool wear. However, the biological relevance and toxic manifestations of these microparticles remain to be determined.

  5. Characterization of copper slag from impoverishment%贫化铜渣的特性分析

    Institute of Scientific and Technical Information of China (English)

    胡建杭; 王华; 赵鲁梅; 李磊; 刘慧利

    2011-01-01

    铜渣是有色金属火法炼铜过程中产出的固体废弃物.通过化学分析、XRD衍射、SEM-EDS和热重等分析铜渣的特性.铜渣主要成分是赤铁矿(α-Fe203)、铁橄榄石(Fe2SiO4)、磁铁矿(Fe3O4)和非晶态硅石,并含有铜及少量镍、钴等有价组分.铁橄榄石和磁铁矿约占总渣量的90%.冷却方式影响渣中铁橄榄石的形成,空冷渣中铁橄榄石的比例明显高于水淬铜渣中的铁橄榄石含量.磁铁矿以多边状、树枝状、放射状结构存在于硅酸盐基体中;铁橄榄石呈柱状、板状、树突状颗粒存在于炉渣基体中;铜矿物或被硅铁氧化物所包裹,或与铜铁矿物共同形成斑状结构及多矿物共生嵌于铁橄榄石基体中.铜渣中铁橄榄石组分首先在491~1 173℃之间氧化转变为赤铁矿和非晶态硅石,其次是磁铁矿发生Fe3O4→γ-Fe2O3→α-Fe2O3的晶型转变过程.加热可以使铁橄榄石、铜和铁的硫化物及磷化物发生氧化反应.%Copper slag is a type of solid waste that generated during pyrometallurgical production of copper. In this study, the quality of copper slag was characterized by chemical analysis, X-ray diffraction (XRD), SEM-EDS and thermogravimetric analysis. The results showed that copper slag has a amorphous structure and contained large amounts of magnetism ferric oxide( Fe2O3 ), fayalite( Fe2SiO4),magnetite(Fe3O4)and some trace elements like Cu, Ni and Co. The major constituents were magnetism ferric oxide and fayalite which comprised more than 90% of the mass. The fayalite content was varied under different cooling techniques. The compositional ratio of fayalite in the air-cooled slag was greater than water-cooled slag. Ferroferric oxide presented as arborized and radicalized shapes in the silicate body. Meanwhile, the shapes of fayalite were observed as column, wattle and dendritic granule in copper slag. Copper mineral was wrapped in silicon-ferric oxide or formed copper-iron ore in the

  6. A new dioxime corrosion inhibitor for the protection and conservation of copper: synthesis, characterization and evaluation in acidic chloride solution

    Science.gov (United States)

    Abu-Baker, Ahmad N.; Al-Qudah, Mahmoud A.

    2016-08-01

    This study aimed to investigate a new dioxime compound as a corrosion inhibitor for copper. The compound (4,6-dihydroxy benzene-1,3-dicarbaldehyde dioxime) was synthesized and characterized by nuclear magnetic resonance spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements were used to compare the dioxime compound with benzotriazole for their effectiveness as corrosion inhibitors for copper in 0.1 M HCl solution. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to investigate the bonding mechanisms and morphological changes of the two inhibitors on the copper surface. The electrochemical techniques showed that the new dioxime compound was more effective than benzotriazole in inhibiting copper corrosion in the acidic chloride medium. The FTIR and SEM results indicated that the dioxime compound was able to coordinate with copper ions and formed a protective film on the copper surface. It was concluded that the new dioxime compound proved effectiveness to be used as a corrosion inhibitor for the protection and conservation of copper.

  7. Copper (II) complexes possessing alkyl-substituted polypyridyl ligands: Structural characterization and in vitro antitumor activity.

    Science.gov (United States)

    Angel, Noah R; Khatib, Raneen M; Jenkins, Julia; Smith, Michelle; Rubalcava, Justin M; Le, Brian Khoa; Lussier, Daniel; Chen, Zhuo Georgia; Tham, Fook S; Wilson, Emma H; Eichler, Jack F

    2017-01-01

    In an effort to find alternatives to the antitumor drug cisplatin, a series of copper (II) complexes possessing alkyl-substituted polypyridyl ligands have been synthesized. Eight new complexes are reported herein: μ-dichloro-bis{2,9-di-sec-butyl-1,10-phenanthrolinechlorocopper(II)} {[((di-sec-butyl)phen)ClCu(μ-Cl)2CuCl((di-sec-butyl)phen)]}(1), 2-sec-butyl-1,10-phenanthrolinedichlorocopper(II) {([mono-sec-butyl)phen) CuCl2} (2), 2,9-di-n-butyl-1,10-phenanthrolinedichlorocopper(II) {[(di-n-butyl)phen) CuCl2}(3), 2-n-butyl-1,10-phenanthrolinedichlorocopper(II) {[(mono-n-butyl)phen) CuCl2} (4), 2,9-di-methyl-1,10-phenanthrolineaquadichlorocopper(II) {[(di-methyl)phen) Cu(H2O)Cl2}(5), μ-dichloro-bis{6-sec-butyl-2,2'-bipyridinedichlorocopper(II)} {((mono-sec-butyl)bipy) ClCu(μ-Cl)2CuCl((mono-sec-butyl)bipy)} (6), 6,6'-di-methyl-2,2'-bipyridinedichlorocopper(II) {(6,6'-di-methyl)bipy) CuCl2} (7), and 4,4'-dimethyl-2,2'-bipyridinedichlorocopper(II) {(4,4'-di-methyl)bipy) CuCl2} (8). These complexes have been characterized via elemental analysis, UV-vis spectroscopy, and mass spectrometry. Single crystal X-ray diffraction experiments revealed the complexes synthesized with the (di-sec-butyl)phen ligand (1) and (mono-sec-butyl)bipy ligand (6) crystallized as dimers in which two copper(II) centers are bridged by two chloride ligands. Conversely, complexes 2, 7, and 8 were isolated as monomeric species possessing distorted tetrahedral geometries, and the [((di-methyl)phen)Cu(H2O)Cl2] (5) complex was isolated as a distorted square pyramidal monomer possessing a coordinating aqua ligand. Compounds 1-8 were evaluated for their in vitro antitumor efficacy. Compounds 1, 5, and 7 in particular were found to exhibit remarkable activity against human derived lung cancer cells, yet this class of copper(II) compounds had minimal cytotoxic effect on non-cancerous cells. In vitro control experiments indicate the activity of the copper(II) complexes most likely does not arise from the

  8. Physicochemical characterization of copper slag and alternatives of friendly environmental management

    Directory of Open Access Journals (Sweden)

    Sánchez M.

    2013-01-01

    Full Text Available Copper slags are usually considered a waste and characterized only by the final copper content. Large and increasing quantities are being produced and disposed of by stockpiling near the metallurgical plants. This paper stresses the importance of physico-chemical characterization when considering uses for slags and the possibility of recovering the valuable metals still remaining in this phase. The purpose of this work is to support and encourage a change in the classical perception of slag from a ‘waste’ to a ‘resource’; promote the development of new technologies for treatment to recover residual values and encourage a search for new uses; with the ultimate objective of eliminating slag stockpiles thereby diminishing the environmental impact of smelting operations. Some of the results of experimental laboratory work done by the authors and examples of commercial applications will be shown. A promising future for valorization and utilization of slags is expected and will provide an example when considering the use of all the other large quantities of wastes generated by the mining industry.

  9. 铝合金搅拌摩擦焊技术研究存在的问题及趋势%Trends and problems for current study of aluminum alloy FSW technology

    Institute of Scientific and Technical Information of China (English)

    杨新岐; 秦红珊

    2009-01-01

    搅拌摩擦焊(Friction Stir Welding-FSW)是目前铝、镁、铜及有色金属等轻合金连接的最先进连接技术之一,FSW与传统熔焊相比,在工艺过程、接头性能等方面具有许多优势.在讨论FSW技术特征、工艺特点及应用研究的基础上,对目前国内外有关FSW技术的研究现状、发展趋势及存在问题进行了详细综述,所涉及的问题是在工业化铝合金结构制造领域(如飞机机身结构、高速客车及汽车车体结构等)大规模推广应用FSW技术必须解决的基础性问题;其次讨论基于FSW研究开发的新思路及新工艺,尤其是搅拌摩擦点焊技术(Friction Stir Spot Welding-FSSW)的原理、特点及在汽车车体轻量化开发中的巨大应用前景.%Friction Stir Welding (FSW) is one of the best advanced joining technologies currently for welding aluminum, magnesium, copper and light metals etc. , and it have many advantages on aspects of processing and performances compared with the traditional fusion welding methods. Based on the discussion of FSW technology mechanism,processing features and industrial application, the trends and problem for the current study of FSW technology have been reviewed in detail and the concerned problems are the key fundamental problems that should be re-solved for the industrial applications of FSW such as airplane body frames,high-speed vehicles and automobile structures etc. Secondly discus-sing the new methods and technologies developed from the FSW investigation, especially the principle and characteristics of Friction Stir Spot Welding (FSSW) technology and its greatly potential application in the automobile industry.

  10. Finite element modelling and updating of friction stir welding (FSW joint for vibration analysis

    Directory of Open Access Journals (Sweden)

    Zahari Siti Norazila

    2017-01-01

    Full Text Available Friction stir welding of aluminium alloys widely used in automotive and aerospace application due to its advanced and lightweight properties. The behaviour of FSW joints plays a significant role in the dynamic characteristic of the structure due to its complexities and uncertainties therefore the representation of an accurate finite element model of these joints become a research issue. In this paper, various finite elements (FE modelling technique for prediction of dynamic properties of sheet metal jointed by friction stir welding will be presented. Firstly, nine set of flat plate with different series of aluminium alloy; AA7075 and AA6061 joined by FSW are used. Nine set of specimen was fabricated using various types of welding parameters. In order to find the most optimum set of FSW plate, the finite element model using equivalence technique was developed and the model validated using experimental modal analysis (EMA on nine set of specimen and finite element analysis (FEA. Three types of modelling were engaged in this study; rigid body element Type 2 (RBE2, bar element (CBAR and spot weld element connector (CWELD. CBAR element was chosen to represent weld model for FSW joints due to its accurate prediction of mode shapes and contains an updating parameter for weld modelling compare to other weld modelling. Model updating was performed to improve correlation between EMA and FEA and before proceeds to updating, sensitivity analysis was done to select the most sensitive updating parameter. After perform model updating, total error of the natural frequencies for CBAR model is improved significantly. Therefore, CBAR element was selected as the most reliable element in FE to represent FSW weld joint.

  11. Nanostructure copper oxocobaltate fabricated by co-precipitation route using copper and cobalt nitrate as precursors: characterization by combined diffuse reflectance and FT infrared spectra.

    Science.gov (United States)

    Habibi, Mohammad Hossein; Rezvani, Zoya

    2014-09-15

    Nanostructure copper oxocobaltate has been fabricated by a co-precipitation route using copper and cobalt nitrate as precursors. The physicochemical properties of copper cobaltate have been characterized via X-ray powder diffractometry (XRD) and field emission scanning electron microscopy (FESEM). The X-ray diffraction patterns indicates the presence of a spinel crystalline phase, (Cu0.30Co0.70)Co2O4, copper oxocobaltate with face-centered cubic lattice and Fd3m space group. FESEM images also illustrated a typical hexagonal morphology with particle size 25 nm, showing a good nanoscale crystalline morphology, which corresponds well with their XRD results. The FTIR spectra confirmed the presence of hydroxyl groups bonded to the metals, stretching vibration of the cobalt-oxygen bond in an octahedral coordination and the characteristic band assigned to the vibration of Cu-O bond. UV-VIS diffuse reflectance spectrum shows a broad band over the whole visible range and broad band between 200 nm and 390 nm ascribed to the ligand to metal charge transfer.

  12. A novel zerovalent manganese for removal of copper ions: synthesis, characterization and adsorption studies

    Science.gov (United States)

    Dada, A. O.; Adekola, F. A.; Odebunmi, E. O.

    2015-11-01

    Synthesis of nanoscale zerovalent manganese (nZVMn) by chemical reduction was carried out in a single pot system under inert environment. nZVMn was characterized using a combination of analytical techniques: Ultraviolet-Visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Energy Dispersive X-ray, BET surface area and Point of Zero Charge. The adsorption physicochemical factors: pH, contact time, adsorbent dose, agitation speed, initial copper ion concentration and temperature were optimized. The kinetic data fitted better to Pseudo second-order, Elovich, fractional power and intraparticle diffusion models and their validity was tested by three statistical models: sum of square error, Chi-square (χ 2) and normalized standard deviation (Δq). Seven of the two-parameter isotherm models [Freundlich, Langmuir, Temkin, Dubinin-Kaganer-Raduskevich (DKR), Halsey, Harkin-Jura and Flory-Huggins] were used to analyse the equilibrium adsorption data. The Langmuir monolayer adsorption capacity (Q max = 181.818 mg/g) obtained is greater than other those of nano-adsorbents utilized in adsorption of copper ions. The equilibrium adsorption data were better described by Langmuir, Freundlich, Temkin, DKR and Halsey isotherm models considering their coefficient of regression (R 2 > 0.90). The values of the thermodynamic parameters: standard enthalpy change ∆H° (+50.27848 kJ mol-1), standard entropy change ∆S° (203.5724 J mol-1 K-1) and the Gibbs free energy change ∆G° revealed that the adsorption process was feasible, spontaneous, and endothermic in nature. The performance of this novel nanoscale zerovalent manganese (nZVMn) suggested that it has a great potential for effective removal of copper ions from aqueous solution.

  13. Characterization of saturation and copper concentration in sand and clay with SIP measurements.

    Science.gov (United States)

    Peruzzo, L.; Schmutz, M.; Franceschi, M.; Hubbard, S. S.

    2016-12-01

    Adsorption by clay minerals, oxides and organic matter is commonly the most effective mechanism controlling the mobility and bioavailability of heavy metals in soil. As contamination processes of natural systems commonly present an important variability with time and space, we aim to show if non-invasive and imaging geophysical methods, specifically Spectral Induced Polarization (SIP), are sensitive to mobility and/or bioavailability of copper. Promising works have recently shown that SIP is sensitive to the different ions dissolved in soil water thanks to their different adsorption behavior. To the best of our knowledge, these works have used clean sand as medium; that is why we need to reach a more generic comprehension of natural soil by including the relevant adsorbents. In this paper, we focus on the copper SIP signature accounting for the presence of two types of clay (montmorillonite and kaolinite), different saturation levels and representative copper concentrations which have been chosen on the base of Cu chemical extractions from soil samples taken in a Cu polluted test site. During the set of SIP measurements one single variable at time is changed: soil components, saturation and solution Cu concentration. At the same time pH and temperature are monitored. A successive modeling will consist of two parts. 1) In order to correctly interpret the SIP measurements and make sure that the signals are only influenced by matrix and fluid composition, thanks to very recent publications, we will model the EM inductive coupling, the effect of the electrodes used and the Maxwell-Wagner effect. 2) Geochemical modeling characterizing the electrical double layer (EDL) state at the different experimental conditions; then we will try to theoretically link the EDL state to the SIP results. This last step could provide an important insight about the polarization mechanisms under the investigated conditions.

  14. Synthesis, characterization and antibacterial studies of a copper(II) levofloxacin ternary complex.

    Science.gov (United States)

    Sousa, Isabel; Claro, Vasco; Pereira, João Lino; Amaral, Ana Luísa; Cunha-Silva, Luís; de Castro, Baltazar; Feio, Maria J; Pereira, Eulália; Gameiro, Paula

    2012-05-01

    Solution behavior of levofloxacin (lvx) complexes with copper(II) in the presence and absence of phen was studied in aqueous solution, by potentiometry. The results obtained show that under physiological conditions (micromolar concentration range and pH 7.4) only copper(II):lvx:phen ternary complexes are stable. Hence, a novel copper(II) ternary complex of fluoroquinolone levofloxacin with nitrogen donor heterocyclic ligand phen was synthesized and characterized by means of UV-Visible and IR spectroscopy, elemental analysis and X-Ray crystallography. In the synthesized complex (1), [Cu(lvx)(phen)(H(2)O)](NO(3)).2H(2)O, levofloxacin acts as a bidentate ligand coordinating to the metal, in its anionic form, through the carbonyl and carboxyl oxygens and phen coordinates through two N-atoms forming the equatorial plane of a distorted square-pyramidal geometry. The fifth ligand of the penta-coordinated Cu(II) centre is occupied axially by an oxygen atom from a water molecule. Minimum inhibitory concentration (MIC) determinations of the complex and comparison with free levofloxacin in various E. coli strains indicated that the Cu-complex is as efficient an antimicrobial as the free antibiotic (both in the case of the dissolved synthesized complex and the complex formed following stoichiometric mixture of the individual components in solution). Moreover, results strongly suggest that the cell intake route of both species is different supporting, therefore, the complex's suitability as a candidate for further biological testing in fluoroquinolone-resistant microorganisms.

  15. Synthesis, characterization and antibacterial studies of a copper(II) lomefloxacin ternary complex.

    Science.gov (United States)

    Fernandes, Patrícia; Sousa, Isabel; Cunha-Silva, Luís; Ferreira, Mariana; de Castro, Baltazar; Pereira, Eulália F; Feio, Maria J; Gameiro, Paula

    2014-02-01

    Solution behavior of lomefloxacin (lmx) complexes with copper(II) in the presence and absence of 1,10-phenanthroline (phen) was studied in aqueous solution, by potentiometry. The results obtained showed that under physiological conditions (micromolar concentration range and pH7.4) only copper(II):lmx:phen ternary complexes are stable. Hence, a novel copper(II) ternary complex of lomefloxacin with the nitrogen donor heterocyclic ligand phen was synthesized and characterized by means of UV-visible and IR spectroscopy, elemental analysis and X-ray crystallography. In the synthesized complex (1), [Cu(lmx)(phen)(NO3)]·5H2O, lmx acts as a bidentate ligand coordinating the metal cation, in its anionic form, through the carbonyl and carboxyl oxygens and phen coordinates through two N-atoms forming the equatorial plane of a distorted square-pyramidal geometry. The fifth ligand of the penta-coordinated Cu(II) center is occupied axially by an oxygen atom from the nitrate ion. Minimum inhibitory concentration (MIC) determinations of the complex and comparison with free lomefloxacin in various E. coli strains indicated that the Cu-complex is an antimicrobial which is as efficient as the free antibiotic but strongly suggest that the cell intake route of both species is different. Moreover, spectrophotometric stability studies suggest that the solution of the complex synthesized is considerably more photostable than the free fluoroquinolone supporting, therefore, the complex's suitability as a candidate for further biological testing in fluoroquinolone-resistant microorganisms with possible reduced side-effects.

  16. A novel zerovalent manganese for removal of copper ions: synthesis, characterization and adsorption studies

    Science.gov (United States)

    Dada, A. O.; Adekola, F. A.; Odebunmi, E. O.

    2017-06-01

    Synthesis of nanoscale zerovalent manganese (nZVMn) by chemical reduction was carried out in a single pot system under inert environment. nZVMn was characterized using a combination of analytical techniques: Ultraviolet-Visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Energy Dispersive X-ray, BET surface area and Point of Zero Charge. The adsorption physicochemical factors: pH, contact time, adsorbent dose, agitation speed, initial copper ion concentration and temperature were optimized. The kinetic data fitted better to Pseudo second-order, Elovich, fractional power and intraparticle diffusion models and their validity was tested by three statistical models: sum of square error, Chi-square ( χ 2) and normalized standard deviation (Δ q). Seven of the two-parameter isotherm models [Freundlich, Langmuir, Temkin, Dubinin-Kaganer-Raduskevich (DKR), Halsey, Harkin-Jura and Flory-Huggins] were used to analyse the equilibrium adsorption data. The Langmuir monolayer adsorption capacity ( Q max = 181.818 mg/g) obtained is greater than other those of nano-adsorbents utilized in adsorption of copper ions. The equilibrium adsorption data were better described by Langmuir, Freundlich, Temkin, DKR and Halsey isotherm models considering their coefficient of regression ( R 2 > 0.90). The values of the thermodynamic parameters: standard enthalpy change ∆ H° (+50.27848 kJ mol-1), standard entropy change ∆ S° (203.5724 J mol-1 K-1) and the Gibbs free energy change ∆ G° revealed that the adsorption process was feasible, spontaneous, and endothermic in nature. The performance of this novel nanoscale zerovalent manganese (nZVMn) suggested that it has a great potential for effective removal of copper ions from aqueous solution.

  17. Synthesis, characterization and superoxide dismutase activity of bi-copper(II)-bisacetato-−phthalicacid[bis(benzyloxy)ethyl]ester

    Indian Academy of Sciences (India)

    Babita Sarma; Pradip K Bhattacharyya; Diganta Kumar Das

    2015-03-01

    A new binuclear copper(II) complex, bridged by the ligand phthalicacid[bis(benzyloxy)ethyl]ester, where each copper(II) is coordinated to one carboxylate (from ligand) and one acetate in square planar mode is reported. The ligand synthesized by the reaction of phthalic anhydride and ethylene glycol, has been characterized by FT-IR, 1HNMR and LCMS. The binuclear Copper(II) complex has been characterized by UV/visible spectra, FTIR spectra, EPR spectra, ESI-MS spectra, magnetic moment measurement and thermogravimetric analysis. DFT calculation has shown a Z type structure for the complex. Excellent superoxide dismutase activity with IC50 value 8.6 × 10−6 M for the complex has been observed.

  18. Biosynthesis, characterization and antimicrobial activity of copper oxide nanoparticles (CONPs) produced using brown alga extract ( Bifurcaria bifurcata)

    Science.gov (United States)

    Abboud, Y.; Saffaj, T.; Chagraoui, A.; El Bouari, A.; Brouzi, K.; Tanane, O.; Ihssane, B.

    2014-06-01

    Recently, biosynthesis of nanoparticles has attracted scientists' attention because of the necessity to develop new clean, cost-effective and efficient synthesis techniques. In particular, metal oxide nanoparticles are receiving increasing attention in a large variety of applications. However, up to now, the reports on the biopreparation and characterization of nanocrystalline copper oxide are relatively few compared to some other metal oxides. In this paper, we report for the first time the use of brown alga ( Bifurcaria bifurcata) in the biosynthesis of copper oxide nanoparticles of dimensions 5-45 nm. The synthesized nanomaterial is characterized by UV-visible absorption spectroscopy and Fourier transform infrared spectrum analysis. X-ray diffraction confirms the formation and the crystalline nature of copper oxide nanomaterial. Further, these nanoparticles were found to exhibit high antibacterial activity against two different strains of bacteria Enterobacter aerogenes (Gram negative) and Staphylococcus aureus (Gram positive).

  19. Fabrication and Characterization of Nitinol-Copper Shape Memory Alloy Bimorph Actuators

    Science.gov (United States)

    Wongweerayoot, E.; Srituravanich, W.; Pimpin, A.

    2015-02-01

    This study aims to examine the effect of annealing conditions on nitinol (NiTi) characteristics and applies this knowledge to fabricate a NiTi-copper shape memory alloy bimorph actuator. The effect of the annealing conditions was investigated at various temperatures, i.e., 500, 600, and 650 °C, for 30 min. With the characterizations using x-ray diffraction, energy dispersive spectroscopy, and differential scanning calorimetry techniques, the results showed that annealing temperatures at 600 and 650 °C were able to appropriately form the crystalline structure of NiTi. However, at these high annealing temperatures, the oxide on a surface was unavoidable. In the fabrication of actuator, the annealing at 650 °C for 30 min was chosen, and it was performed at two pre-stressing conditions, i.e., straight and curved molds. From static and dynamic response experiments, the results suggested that the annealing temperature significantly affected the deflection of the actuator. On the other hand, the effect of pre-stressing conditions was relatively small. Furthermore, the micro gripper consisting of two NiTi-copper bimorph actuators successfully demonstrated for the viability of small object manipulation as the gripper was able to grasp and hold a small plastic ball with its weight of around 0.5 mg.

  20. Copper Nanoparticles Mediated by Chitosan: Synthesis and Characterization via Chemical Methods

    Directory of Open Access Journals (Sweden)

    Muhammad Sani Usman

    2012-12-01

    Full Text Available Herein we report a synthesis of copper nanoparticles (Cu-NPs in chitosan (Cts media via a chemical reaction method. The nanoparticles were synthesized in an aqueous solution in the presence of Cts as stabilizer and CuSO4·5H2O precursor. The synthesis proceeded with addition of NaOH as pH moderator, ascorbic acid as antioxidant and hydrazine as the reducing agent. The characterization of the prepared NPs was done using ultraviolet-visible spectroscopy, which showed a 593 nm copper band. The Field Emission Scanning Electron Microscope (FESEM images were also observed, and found to be in agreement with the UV-Vis result, confirming the formation of metallic Cu-NPs. The mean size of the Cu-NPs was estimated to be in the range of 35–75 nm using X-ray diffraction. XRD was also used in analysis of the crystal structure of the NPs. The interaction between the chitosan and the synthesized NPs was studied using Fourier transform infrared (FT-IR spectroscopy, which showed the capping of the NPs by Cts.

  1. Surface topographic characterization for polyamide composite injection molds made of aluminum and copper alloys.

    Science.gov (United States)

    Pereira, A; Hernández, P; Martinez, J; Pérez, J A; Mathia, T G

    2014-01-01

    In order to ensure flexibility and rapid new product development, the mold industry made use of soft materials for cavity inserts in injection molds. However, materials of this kind are prone to wear. This article analyzes the topographic characterization of the surface and wear processes in injection molds cavities. Two materials have been used to produce the cavities: aluminum alloy EN AW‐6082 T4 and copper alloy Cu Zn39 Pb3. The surface topography was measured with the use of optical interferometry profiling technology; roughness and surface parameters were determined according to ISO 4287, ISO 25178, and EUR 15178N. In order to complete this research, an experimental part with different thicknesses and shapes was designed, and cavity inserts of aluminum and copper were made. Polyamide PA6, with 30% fiberglass reinforcement, was employed in the experimental procedure. Measurements of cavity mold surfaces were performed after 9,200 cycles on each mold and at different locations on the mold. The surface measurement was made with a white light vertical scanning interferometry, also known as coherence scanning interferometry (ISO DIS 25178‐604). The results are analyzed and differences between the two types of cavity inserts materials are discussed.

  2. Synthesis, Characterization, Molecular Modeling, and DNA Interaction Studies of Copper Complex Containing Food Additive Carmoisine Dye.

    Science.gov (United States)

    Shahabadi, Nahid; Akbari, Alireza; Jamshidbeigi, Mina; Khodarahmi, Reza

    2016-06-02

    A copper complex of carmoisine dye; [Cu(carmoisine)2(H2O)2]; was synthesized and characterized by using physico-chemical and spectroscopic methods. The binding of this complex with calf thymus (ct) DNA was investigated by circular dichroism, absorption studies, emission spectroscopy, and viscosity measurements. UV-vis results confirmed that the Cu complex interacted with DNA to form a ground-state complex and the observed binding constant (2× 10(4) M(-1)) is more in keeping with the groove bindings with DNA. Furthermore, the viscosity measurement result showed that the addition of complex causes no significant change on DNA viscosity and it indicated that the intercalation mode is ruled out. The thermodynamic parameters are calculated by van't Hoff equation, which demonstrated that hydrogen bonds and van der Waals interactions played major roles in the reaction. The results of circular dichroism (CD) suggested that the complex can change the conformation of DNA from B-like form toward A-like conformation. The cytotoxicity studies of the carmoisine dye and its copper complex indicated that both of them had anticancer effects on HT-29 (colon cancer) cell line and they may be new candidates for treatment of the colon cancer.

  3. Temperature characterization of dielectric permittivity and AC conductivity of nano copper oxide-doped polyaniline composite

    Science.gov (United States)

    Shubha, L. N.; Madhusudana Rao, P.

    2016-06-01

    The polyaniline/copper oxide (PANI/CuO) nanocomposite was prepared by mixing solutions of polyaniline and copper oxide nanoparticles in dimethyl sulfoxide (DMSO). The synthesized polymer nanocomposites were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM) and UV-visible spectroscopy. The characteristic peaks in XRD and UV-visible spectra confirmed the presence of CuO in the polymer structure. SEM images indicated morphological changes in the composite matrix as compared to the pristine PANI. The DC conductivity measurements were performed using two-probe method for various temperatures. AC conductivity and dielectric response of the composites were investigated in the frequency range of 102-106Hz using LCR meter. Dielectric permittivity ɛ‧(w) and dielectric loss factor ɛ‧‧(w) were investigated. It was observed that ɛ‧(w) and ɛ‧‧(w) decrease with increase in frequency at all temperatures. At a particular frequency it is observed that both ɛ‧(w) and ɛ‧‧(w) increase with increase in temperature. It was also observed that AC conductivity increased with increase in frequency and temperature.

  4. Transition metal complexes of neocryptolepine analogues. Part I: Synthesis, spectroscopic characterization, and invitro anticancer activity of copper(II) complexes

    Science.gov (United States)

    Emam, Sanaa Moustafa; El Sayed, Ibrahim El Tantawy; Nassar, Nagla

    2015-03-01

    New generation of copper(II) complexes with aminoalkylaminoneocryptolepine as bidentate ligands has been synthesized and it is characterized by elemental analyses, magnetic moment, spectra (IR, UV-Vis, 1H NMR and ESR) and thermal studies. The IR data suggest the coordination modes for ligands which behave as a bidentate with copper(II) ion. Based on the elemental analysis, magnetic studies, electronic and ESR data, binuclear square planar geometry was proposed for complexes 7a, 7b, square pyramidal for 9a, 9b and octahedral for 8a, 8b, 10a, 10b. The molar conductance in DMF solution indicates that all complexes are electrolyte except 7a and 7b. The ESR spectra of solid copper(II) complexes in powder form showed an axial symmetry with 2B1g as a ground state and hyperfine structure. The thermal stability and degradation of the ligands and their metal complexes were studied employing DTA and TG methods. The metal-free ligands and their copper(II) complexes were tested for their in vitro anticancer activity against human colon carcinoma (HT-29). The results showed that the synthesized copper(II) complexes exhibited higher anticancer activity than their free ligands. Of all the studied copper(II) complexes, the bromo-substituted complex 9b exhibited high anticancer activity at low micromolar inhibitory concentrations (IC50 = 0.58 μM), compared to the other complexes and the free ligands.

  5. Synthesis, structural characterization, and magnetic properties of a copper-gadolinium complex derived from a hydroxybenzohydrazide ligand.

    Science.gov (United States)

    Costes, Jean-Pierre; Duhayon, Carine; Vendier, Laure

    2014-02-17

    The reaction of hydroxybenzohydrazide with o-vanillin yields 2-hydroxy-N'-[(2-hydroxy-3-methoxyphenyl)methylidene]benzohydrazide (LH3), a ligand that is able to give mononuclear and tetranuclear copper complexes but also to associate copper and gadolinium ions in a Cu2-Gd2 heterotetranuclear complex. This synthesis is successful if the Gd ions, which are acidic in protic solvents, are introduced in a basic methanol solution of the mononuclear copper complex. In the absence of piperidine, the addition of Gd ions to a methanol solution of the mononuclear copper complex only yields a tetranuclear cubane-type copper complex. This work reports on the first structural characterization of a copper-gadolinium complex involving a benzohydrazide ligand. The resulting complex consists of two Cu-Gd pairs linked by a dihydroxo Gd-Gd bridge, in which the Cu and Gd ions are bridged by a nonsymmetric phenoxo-hydroxo bridge. The magnetostructural correlation between the ferromagnetic coupling constant and the hinge angle observed in symmetrical double-phenoxo Cu-Gd bridges remains valid for dissymmetric Cu-Gd bridges and confirms the preponderance of the structural factor over the nature of the bridge. This tetranuclear complex corresponds to two S = 4 units linked through a dihydroxo bridge introducing a weak antiferromagnetic Gd-Gd interaction and impeding the existence of a S = 8 ground state.

  6. Characterization of Copper Corrosion Products in Drinking Water by Combining Electrochemical and Surface Analyses

    Science.gov (United States)

    This study focuses on the application of electrochemical approaches to drinking water copper corrosion problems. Applying electrochemical approaches combined with copper solubility measurements, and solid surface analysis approaches were discussed. Tafel extrapolation and Electro...

  7. Characterization of Copper Corrosion Products Formed in Drinking Water by Combining Electrochemical and Surface Analyses

    Science.gov (United States)

    This study focuses on the application of electrochemical approaches to drinking water copper corrosion problems. Applying electrochemical approaches combined with copper solubility measurements, and solid surface analysis approaches were discussed. Tafel extrapolation and Electro...

  8. Preparation and characterization of nanostructured copper bismuth diselenide thin films from a chemical route

    Indian Academy of Sciences (India)

    R H Bari; L A Patil

    2010-12-01

    Thin films of copper bismuth diselenide were prepared by chemical bath deposition technique onto glass substrate below 60°C. The deposition parameters such as time, temperature of deposition and pH of the solution, were optimized. The set of films having different elemental compositions was prepared by varying Cu/Bi ratio from 0.13–1.74. Studies on structure, composition, morphology, optical absorption and electrical conductivity of the films were carried out and discussed. Characterization includes X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray analysis (EDAX), absorption spectroscopy, and electrical conductivity. The results are discussed and interpreted.

  9. Characterization of the biosorption of cadmium, lead and copper with the brown alga Fucus vesiculosus

    Energy Technology Data Exchange (ETDEWEB)

    Mata, Y.N. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid s/n, Madrid 28040 (Spain); Blazquez, M.L. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid s/n, Madrid 28040 (Spain)], E-mail: mlblazquez@quim.ucm.es; Ballester, A.; Gonzalez, F.; Munoz, J.A. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid s/n, Madrid 28040 (Spain)

    2008-10-30

    The recovery of cadmium, lead and copper with the brown alga Fucus vesiculosus was characterized and quantified. The biosorption data fitted the pseudo-second order and Langmuir isotherm models, but did not adjust to the intraparticle diffusion model. The metal uptakes deduced from the pseudo-second order kinetic model and the Langmuir isotherm model followed a similar sequence: Cu > Cd {approx} Pb. The Langmuir maximum metal uptakes were: 0.9626 mmol/g, Pb 1.02 mmol/g, and Cu 1.66 mmol/g. According to the equilibrium constants of this isotherm model, the affinity of metals for the biomass followed this order: Pb > Cu > Cd. Biosorption was accomplished by ion exchange between metals in solution and algal protons, calcium and other light metals, and by complexation of the adsorbed metals with algal carboxyl groups. FTIR spectra showed a shift in the bands of carboxyl, hydroxyl and sulfonate groups.

  10. Characterization of the biosorption of cadmium, lead and copper with the brown alga Fucus vesiculosus.

    Science.gov (United States)

    Mata, Y N; Blázquez, M L; Ballester, A; González, F; Muñoz, J A

    2008-10-30

    The recovery of cadmium, lead and copper with the brown alga Fucus vesiculosus was characterized and quantified. The biosorption data fitted the pseudo-second order and Langmuir isotherm models, but did not adjust to the intraparticle diffusion model. The metal uptakes deduced from the pseudo-second order kinetic model and the Langmuir isotherm model followed a similar sequence: Cu>Cd approximately Pb. The Langmuir maximum metal uptakes were: 0.9626 mmol/g, Pb 1.02 mmol/g, and Cu 1.66 mmol/g. According to the equilibrium constants of this isotherm model, the affinity of metals for the biomass followed this order: Pb>Cu>Cd. Biosorption was accomplished by ion exchange between metals in solution and algal protons, calcium and other light metals, and by complexation of the adsorbed metals with algal carboxyl groups. FTIR spectra showed a shift in the bands of carboxyl, hydroxyl and sulfonate groups.

  11. Synthesis and Characterization of In-situ Copper-Niobium Carbide Composite

    Science.gov (United States)

    Zuhailawati, H.; Othman, R.; Bui, D. L.; Umemoto, M.

    2008-03-01

    In this work, synthesis of copper matrix composite powder reinforced by in situ niobium carbide particle was prepared by mechanical alloying of elemental powder and subsequent heat treatment. Elemental powders of Cu-Nb-C correspond to Cu-40wt%Nb-10%wtC composition was milled for 54 hours at room temperature in a planetary ball mill. The effect of heat treatment temperature on the formation of niobium carbide was analyzed. Characterization by X-ray diffraction was done on the milled powder and heat-treated powder in order to investigate NbC formation. Results indicate that NbC began to precipitate after mechanical alloying for about 54h with heat treatment temperature of 900 °C and 1000 °C.

  12. Characterization of submonolayer film composed of soft-landed copper nanoclusters on HOPG

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Shyamal, E-mail: shyamal.mondal@saha.ac.in; Das, Pabitra; Chowdhury, Debasree; Bhattacharyya, S. R. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700 064 (India)

    2015-06-24

    Preformed Copper nanoclusters are deposited on highly oriented pyrolytic graphite (HOPG) at very low energy. For the study of chemical composition X-ray Photoelectron Spectroscopy (XPS) is performed for a wide range of binding energy without exposing the sample in the ambient. Morphological aspects of the supported clusters are characterized employing high resolution scanning electron microscope (SEM). Different types of morphology are observed depending on the nature of the substrate surface. Big fractal islands are formed on terraces while at the step edges small islands are found to form. Ex-situ cathodoluminescence (CL) measurement shows peak at 558 nm wavelength which corresponds to the band gap of 2.22 eV which is due to Cu{sub 2}O nanocrystals formed due to oxidation of the deposited film in ambient.

  13. Characterization of a copper spark discharge plasma in argon atmosphere used for nanoparticle generation

    Science.gov (United States)

    Kohut, Attila; Galbács, Gábor; Márton, Zsuzsanna; Geretovszky, Zsolt

    2017-04-01

    Spark discharge nanoparticle generation is a dynamically developing application of discharge plasmas. In the present study a spark plasma used for nanoparticle generation is characterized by means of spatially and temporally resolved optical emission spectroscopy (OES) supplemented by fast imaging. The data acquired during the generation of copper nanoparticles in argon ambient is used to describe the spatial and temporal evolution of the species in the spark gap and to derive plasma parameters such as excitation temperature and electron concentration on one hand, and the concentration of the Cu species eroded by a single spark on the other. It is shown that temporally and spatially resolved OES together with a simple equilibrium model are efficient tools to estimate the characteristics of the spark discharge plasma that typically exists in spark discharge nanoparticle generators.

  14. Synthesis, characterization, magnetic and electrochemical properties of a new 3D hexa-copper-substituted germanotungstate

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yanzhou; Luo, Jie; Zhang, Yanting [Institute of Molecular and Crystal Engineering, Henan Key Lab of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); Zhao, Junwei, E-mail: zhaojunwei@henu.edu.cn [Institute of Molecular and Crystal Engineering, Henan Key Lab of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); Basic Experiment Teaching Center, Henan University, Kaifeng, Henan 475004 (China); Chen, Lijuan, E-mail: ljchen@henu.edu.cn [Institute of Molecular and Crystal Engineering, Henan Key Lab of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Ma, Pengtao; Niu, Jingyang [Institute of Molecular and Crystal Engineering, Henan Key Lab of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China)

    2013-09-15

    An inorganic–organic hybrid hexa-copper-substituted germanotungstate Na{sub 2}[Cu(dap){sub 2}]{sub 2}[Cu(dap){sub 2}] ([Cu{sub 6}(H{sub 2}O){sub 2}(dap){sub 2}][B-α-GeW{sub 9}O{sub 34}]{sub 2})·4H{sub 2}O (1) (dap=1,2-diaminopropane) has been hydrothermally prepared and characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP–AES) analyses, IR spectra, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. 1 displays the six-connected 3D network with the long topological (O′Keefe) vertex symbol is 4·4·6{sub 4}·4·4·4·4·6{sub 4}·4·4·4·6{sub 4}·4·4·4 and the short vertex (Schläfli) symbol of 4{sup 12}6{sup 3}. Magnetic measurements indicate that there are the overall ferromagnetic exchange interactions in the belt-like hexa-Cu{sup II} cluster in 1. Furthermore, the electrochemical behavior and electrocatalysis of 1 modified carbon paste electrode (1-CPE) have been studied. The reductions of nitrite, bromate and hydrogen peroxide are principally mediated by the W{sup VI}-based wave. - Graphical abstract: A hexa-Cu{sup II} sandwiched germanotungstate has been synthesized and structurally characterized. The magnetic, solid-state electrochemical and electrocatalytic properties have been investigated. Display Omitted - Highlights: • Transition-metal substituted polyoxometalates. • Hexa-copper-substituted germanotungstate. • Six-connected 3D network. • Electrocatalytic reduction of nitrite, bromate and hydrogen peroxide.

  15. Microstructural Characterization and Hardness Evaluation of Friction Stir Welded Composite AA6061-4.5Cu-5SiC (Wt.%

    Directory of Open Access Journals (Sweden)

    A.K. Shettigar

    2013-07-01

    Full Text Available Recent developments in advanced materials research have led to the emergence of new materials having features like low density, high strength to weight ratio, excellent mechanical properties, heat and corrosion resistance. In friction stir welding (FSW, a non-consumable rotating welding tool is used to generate the frictional heat and plastic deformation of the material in the welding zone, which is in the solid state. The advantages of FSW as compared to the fusion welding are high joint strength, less defect weld, uniform distribution of grain structure in the weld zone and low power consumption. AA6061with 4.5 % weight of copper and 5 % weight of SiC composite material has been prepared to conduct experiment and carry out characterization, evaluation of the mechanical properties. Micro-structural characterization of the weld zone is carried out by scanning electron microscope (SEM. Evaluation of hardness was also carried out across the weld zone. A successful method for FSW of AA6061-4.5(wt.% Cu-5(wt.% SiC has been developed.Defence Science Journal, 2013, 63(4, pp.429-434, DOI:http://dx.doi.org/10.14429/dsj.63.4869

  16. Microstructural Characterization and Hardness Evaluation of Friction Stir Welded Composite AA6061-4.5Cu-5SiC (Wt.%

    Directory of Open Access Journals (Sweden)

    A.K. Shettigar

    2013-07-01

    Full Text Available Recent developments in advanced materials research have led to the emergence of new materials having features like low density, high strength to weight ratio, excellent mechanical properties, heat and corrosion resistance. In friction stir welding (FSW, a non-consumable rotating welding tool is used to generate the frictional heat and plastic deformation of the material in the welding zone, which is in the solid state. The advantages of FSW as compared to the fusion welding are high joint strength, less defect weld, uniform distribution of grain structure in the weld zone and low power consumption. AA6061with 4.5 % weight of copper and 5 % weight of SiC composite material has been prepared to conduct experiment and carry out characterization, evaluation of the mechanical properties. Micro-structural characterization of the weld zone is carried out by scanning electron microscope (SEM. Evaluation of hardness was also carried out across the weld zone. A successful method for FSW of AA6061-4.5(wt.% Cu-5(wt.% SiC has been developed.

  17. Hybrid joints manufactured by ultrasound enhanced friction stir welding (USE-FSW) - corrosion properties

    Science.gov (United States)

    Benfer, S.; Fürbeth, W.; Thomä, M.; Wagner, G.; Straß, B.; Wolter, B.

    2017-03-01

    To realize lightweight structures of material combinations like aluminum/magnesium and aluminum/steel an Ultrasound Enhanced Friction Stir Welding (USE-FSW) process was used. This process has a beneficial influence on the resulting microstructure (elimination of the brittle intermetallic phase Al3Mg2 as coherent layer) and the mechanical properties (increased tensile strength) of Al/Mg-joints and was now also applied for Al/steel-hybrid joints. Besides the mechanical properties the corrosion properties of the hybrid joints may play a significant role concerning the later use of the hybrid materials. Therefore, the corrosion properties of various hybrid joints have been investigated by different methods. With the Scanning Kelvin Probe (SKP) Volta potential differences between the base alloys and the welded area were investigated in air. The two-dimensional color-plots illustrate not only the Volta potential differences between the different phases but also their oxidation properties in air during the measurement time. Electrochemical measurements (open circuit potential and potentiodynamic polarization) have been carried out for the investigation of the corrosion properties of the FSW and USE-FSW hybrid joints in 0.5 molar NaCl solution. A three electrode setup within a mini-cell was used to enable measurements on different areas of the joints. This allows to observe the corrosion activity of the base alloys and the nugget phase separately. Differences between Al/steel-hybrid joints processed with and without ultrasound enhancement are discussed and compared with Al/Mg-hybrids.

  18. FSW of Aluminum Tailor Welded Blanks across Machine Platforms

    Energy Technology Data Exchange (ETDEWEB)

    Hovanski, Yuri; Upadhyay, Piyush; Carlson, Blair; Szymanski, Robert; Luzanski, Tom; Marshall, Dustin

    2015-02-16

    Development and characterization of friction stir welded aluminum tailor welded blanks was successfully carried out on three separate machine platforms. Each was a commercially available, gantry style, multi-axis machine designed specifically for friction stir welding. Weld parameters were developed to support high volume production of dissimilar thickness aluminum tailor welded blanks at speeds of 3 m/min and greater. Parameters originally developed on an ultra-high stiffness servo driven machine where first transferred to a high stiffness servo-hydraulic friction stir welding machine, and subsequently transferred to a purpose built machine designed to accommodate thin sheet aluminum welding. The inherent beam stiffness, bearing compliance, and control system for each machine were distinctly unique, which posed specific challenges in transferring welding parameters across machine platforms. This work documents the challenges imposed by successfully transferring weld parameters from machine to machine, produced from different manufacturers and with unique control systems and interfaces.

  19. Structural characterization of a metal-based perfusion tracer: copper(II) pyruvaldehyde bis(N4-methylthiosemicarbazone).

    Science.gov (United States)

    John, E; Fanwick, P E; McKenzie, A T; Stowell, J G; Green, M A

    1989-01-01

    Copper(II) pyruvaldehyde bis(N4-methylthiosemicarbazone), Cu(PTSM), has been obtained as a dark red crystalline solid from EtOH-DMSO solvent mixture and structurally characterized by x-ray crystallography. The molecule possesses the expected pseudo-square planar N2S2 metal coordination sphere; however, the copper center also interacts through its axial coordination site with the sulfur atom of an adjacent Cu(PTSM) molecule in the crystal lattice. The structure of this compound is compared with the structures of other metal complexes that have been proposed in the nuclear medicine literature as perfusion tracers.

  20. Characterizing copper flows in international trade of China, 1975-2015.

    Science.gov (United States)

    Zhang, Ling; Chen, Tianming; Yang, Jiameng; Cai, Zhijian; Sheng, Hu; Yuan, Zengwei; Wu, Huijun

    2017-12-01

    Since the economic reform, China has actively participated in the global market with rapid industrialization and gradually dominated the utilization and consumption of some critical materials, one of which is copper. China has reigned the global anthropogenic cycle of copper since 2004. We explore copper flows along with the international trade of China during 1975-2015, through life cycle lens, from ore to final products. Our main finding is that China has become more active in the copper-related trade, indicated by its great increase in trade volume and the number of trade partners. The physical volume of copper flows through trade increased over 119 times between 1975 and 2015, mainly because of more imported raw materials of copper and exported copper products. Generally, China is a net importer of copper, with increasing import dependence through the study period, whereas the degree of dependence slightly decreased from 2010 to 2015. The indicator of Export Support Rate took a decreasing percentage, which has fallen about 35% since 2010. It suggests China's changing position in the global resource and manufacturing market. In terms of trade price of different copper products, the price of imported copper concentrate was noticeably higher than that of exported one, revealing the poor copper resource endowment of China; while the different trend of copper semis in recent years signifies that China is in urgent need to improve its capability of producing high value-added semis. From international trade perspective, the copper resource of China presented stable supply as well as demand. The One Belt One Road strategy proposed by the state will further expand both the resource and market of copper. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Synthesis, crystallographic characterization and electrochemical property of a copper(II) complex of the anticancer agent elesclomol.

    Science.gov (United States)

    Vo, Nha Huu; Xia, Zhiqiang; Hanko, Jason; Yun, Tong; Bloom, Steve; Shen, Jianhua; Koya, Keizo; Sun, Lijun; Chen, Shoujun

    2014-01-01

    Elesclomol is a novel anticancer agent that has been evaluated in a number of late stage clinical trials. A new and convenient synthesis of elesclomol and its copper complex is described. X-ray crystallographic characterization and the electrochemical properties of the elesclomol copper(II) complex are discussed. The copper(II) cation is coordinated in a highly distorted square-planar geometry to each of the sulphur and amide nitrogen atoms of elesclomol. Electrochemical measurements demonstrate that the complex undergoes a reversible one-electron reduction at biologically accessible potentials. In contrast the free elesclomol is found electrochemically inactive. This evidence is in strong support of the mechanism of action we proposed for the anticancer activity of elesclomol.

  2. Study and characterization of positive electrolytes for application in the aqueous all-copper redox flow battery

    Science.gov (United States)

    Sanz, Laura; Lloyd, David; Magdalena, Eva; Palma, Jesús; Anderson, Marc; Kontturi, Kyösti

    2015-03-01

    In recent studies, the employment of the aqueous solution system comprised of Cu(II)-Cu(I)-Cl system was addressed for massive energy storage in Redox Flow Batteries (RFBs) [5,6], providing important practical advantages compared to the widespread all-vanadium or Zn/Br systems [5]. The substitution of vanadium electrolytes by copper-chloride electrolytes allows the simplification of the process and notably reduces the cost, allowing for a better commercialization of RFBs. Here, a complete physico-chemical characterization of positive copper electrolytes and their electrochemical performance using different supporting electrolytes, HCl and CaCl2, is presented. Once the physical properties and the electrochemical performance of each one of the supporting electrolytes were determined, the final composition of supporting electrolyte for this Cu(II)/Cu(I) redox couple could be optimized by mixing different sources of chloride, regarding its practical application in the all-copper RFB.

  3. Hydrogen Bonds Dictate the Coordination Geometry of Copper: Characterization of a Square-Planar Copper(I) Complex.

    Science.gov (United States)

    Dahl, Eric W; Szymczak, Nathaniel K

    2016-02-24

    6,6''-Bis(2,4,6-trimethylanilido)terpyridine (H2Tpy(NMes)) was prepared as a rigid, tridentate pincer ligand containing pendent anilines as hydrogen bond donor groups in the secondary coordination sphere. The coordination geometry of (H2 Tpy(NMes))copper(I)-halide (Cl, Br and I) complexes is dictated by the strength of the NH-halide hydrogen bond. The Cu(I)Cl and Cu(II)Cl complexes are nearly isostructural, the former presenting a highly unusual square-planar geometry about Cu(I) . The geometric constraints provided by secondary interactions are reminiscent of blue copper proteins where a constrained geometry, or entatic state, allows for extremely rapid Cu(I)/Cu(II) electron-transfer self-exchange rates. Cu(H2 Tpy(NMes))Cl shows similar fast electron transfer (≈10(5)  m(-1)  s(-1)) which is the same order of magnitude as biological systems.

  4. Characterization of boron carbide particulate reinforced in situ copper surface composites synthesized using friction stir processing

    Energy Technology Data Exchange (ETDEWEB)

    Sathiskumar, R., E-mail: sathiscit2011@gmail.com [Department of Mechanical Engineering, Coimbatore Institute of Technology, Coimbatore, 641 014 Tamil Nadu (India); Murugan, N., E-mail: murugan@cit.edu.in [Department of Mechanical Engineering, Coimbatore Institute of Technology, Coimbatore, 641 014 Tamil Nadu (India); Dinaharan, I., E-mail: dinaweld2009@gmail.com [Department of Mechanical Engineering, V V College of Engineering, Tisaiyanvilai, 627 657 Tamil Nadu (India); Vijay, S.J., E-mail: vijayjoseph@karunya.edu [Centre for Research in Metallurgy (CRM), School of Mechanical Sciences, Karunya University, Coimbatore, 641 114 Tamil Nadu (India)

    2013-10-15

    Friction stir processing has evolved as a novel solid state technique to fabricate surface composites. The objective of this work is to apply the friction stir processing technique to fabricate boron carbide particulate reinforced copper surface composites and investigate the effect of B{sub 4}C particles and its volume fraction on microstructure and sliding wear behavior of the same. A groove was prepared on 6 mm thick copper plates and packed with B{sub 4}C particles. The dimensions of the groove was varied to result in five different volume fractions of B{sub 4}C particles (0, 6, 12, 18 and 24 vol.%). A single pass friction stir processing was done using a tool rotational speed of 1000 rpm, travel speed of 40 mm/min and an axial force of 10 kN. Metallurgical characterization of the Cu/B{sub 4}C surface composites was carried out using optical microscope and scanning electron microscope. The sliding wear behavior was evaluated using a pin-on-disk apparatus. Results indicated that the B{sub 4}C particles significantly influenced the area, dispersion, grain size, microhardness and sliding wear behavior of the Cu/B{sub 4}C surface composites. When the volume fraction of B{sub 4}C was increased, the wear mode changed from microcutting to abrasive wear and wear debris was found to be finer. Highlights: • Fabrication of Cu/B{sub 4}C surface composite by friction stir processing • Analyzing the effect of B{sub 4}C particles on the properties of Cu/B4C surface composite • Increased volume fraction of B{sub 4}C particles reduced the area of surface composite. • Increased volume fraction of B{sub 4}C particles enhanced the microhardness and wear rate. • B{sub 4}C particles altered the wear mode from microcutting to abrasive.

  5. Plasma Deposition and Characterization of Copper-doped Cobalt Oxide Nanocatalysts

    Directory of Open Access Journals (Sweden)

    Jacek TYCZKOWSKI

    2013-09-01

    Full Text Available A series of pure and copper-doped cobalt oxide films was prepared by plasma-enhanced metalorganic chemical vapor deposition (PEMOCVD. The effect of Cu-doping on the chemical structure and morphology of the deposited films was investigated. Raman and FTIR spectroscopies were used to characterize the chemical structure and morphology of the produced films. The bulk composition and homogeneity of the samples were investigated by energy dispersive X-ray microanalysis (EDX, and X-ray photoelectron spectroscopy (XPS was employed to assess the surface chemical composition of pure and doped materials. The obtained results permit to affirm that the PEMOCVD technique is a simple, versatile and efficient method for providing homogeneous layers of cobalt oxides with a different content of copper. It has been found that pure cobalt oxide films mainly contain Co3O4 in the form of nanoclusters whereas the films doped with Cu are much more complex, and CoOx (also Co3O4, mixed Co-Cu oxides and CuOx nanoclusters are detected in them. Preliminary catalytical tests show that Cu-doped cobalt oxide films allow to initiate catalytic combustion of n-hexane at a lower temperature compared to the pure cobalt oxide (Co3O4 films. From what has been stated above, the plasma-deposited thin films of Cu-doped cobalt oxides pave the way towards a new class of nanomaterials with interesting catalytic properties. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.2320

  6. Syntheses, characterization and properties of silver, copper and palladium complexes from bis(oxazoline)-containing ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kuai, Hai-Wei, E-mail: hyitshy@126.com; Cheng, Xiao-Chun; Li, Deng-Hao; Hu, Tao; Zhu, Xiao-Hong

    2015-08-15

    The reactions of 2,6-di(2-oxazolyl)pyridine (L{sup 1}) and 2,6-bis[(S)-4-phenyl-2-oxazolyl]pyridine (L{sup 2}) with silver, copper and palladium salts to yield six new complexes: ([Ag{sub 5}(L{sup 1}){sub 5}](BF{sub 4}){sub 5}){sub n} (1), ([Ag(L{sup 1})](SbF{sub 6})){sub n} (2), [Cu{sub 4}I{sub 4}(L{sup 1}){sub 2}] (3), [Cu{sub 6}I{sub 6}(L{sup 1}){sub 2}] (4), [Pd(L′{sup 1})(OAc)] (5), [Pd(L′{sup 2})Cl] (6), which were fully characterized by single-crystal and powder X-ray diffraction, IR, elemental and thermogravimetric analyses. 1 and 2 are a pair of Ag-oxazoline helical chain structure complexes. The spiral directions of chains are opposite in 1, while identical in 2; the measurement of CD spectra can further confirm their meso and chiral structures. Complexes 3 and 4 show eight-nuclear and twelve-nuclear iodine–cuprous cluster structure. Their structural diversity is induced by different molar ratios of CuI:L{sup 1}. Complexes 5 and 6 are discrete mononuclear palladium complexes. In situ oxazolyl-ring-opening reactions take place in the syntheses of them and the L{sup 1} and the L{sup 2} were transformed to their oxazolyl-ring opened derivatives L′{sup 1} and L′{sup 2}. Moreover, fluorescence, non-linear optical properties, and ferroelectric properties have been investigated. - Graphical abstract: 2,6-di(2-oxazolyl)pyridine (L{sup 1}) reacts with silver and copper salts to yield helical and cluster structure complexes. - Highlights: • Helical and cluster structure complexes. • In situ oxazolyl-ring-opening reactions. • Fluorescence, non-linear optical properties, and ferroelectric properties.

  7. Synthesis, Characterization, and Processing of Copper, Indium, and Gallium Dithiocarbamates for Energy Conversion Applications

    Science.gov (United States)

    Duraj, S. A.; Duffy, N. V.; Hepp, A. F.; Cowen, J. E.; Hoops, M. D.; Brothrs, S. M.; Baird, M. J.; Fanwick, P. E.; Harris, J. D.; Jin, M. H.-C.

    2009-01-01

    Ten dithiocarbamate complexes of indium(III) and gallium(III) have been prepared and characterized by elemental analysis, infrared spectra and melting point. Each complex was decomposed thermally and its decomposition products separated and identified with the combination of gas chromatography/mass spectrometry. Their potential utility as photovoltaic materials precursors was assessed. Bis(dibenzyldithiocarbamato)- and bis(diethyldithiocarbamato)copper(II), Cu(S2CN(CH2C6H5)2)2 and Cu(S2CN(C2H5)2)2 respectively, have also been examined for their suitability as precursors for copper sulfides for the fabrication of photovoltaic materials. Each complex was decomposed thermally and the products analyzed by GC/MS, TGA and FTIR. The dibenzyl derivative complex decomposed at a lower temperature (225-320 C) to yield CuS as the product. The diethyl derivative complex decomposed at a higher temperature (260-325 C) to yield Cu2S. No Cu containing fragments were noted in the mass spectra. Unusual recombination fragments were observed in the mass spectra of the diethyl derivative. Tris(bis(phenylmethyl)carbamodithioato-S,S'), commonly referred to as tris(N,N-dibenzyldithiocarbamato)indium(III), In(S2CNBz2)3, was synthesized and characterized by single crystal X-ray crystallography. The compound crystallizes in the triclinic space group P1(bar) with two molecules per unit cell. The material was further characterized using a novel analytical system employing the combined powers of thermogravimetric analysis, gas chromatography/mass spectrometry, and Fourier transform infrared (FT-IR) spectroscopy to investigate its potential use as a precursor for the chemical vapor deposition (CVD) of thin film materials for photovoltaic applications. Upon heating, the material thermally decomposes to release CS2 and benzyl moieties in to the gas phase, resulting in bulk In2S3. Preliminary spray CVD experiments indicate that In(S2CNBz2)3 decomposed on a Cu substrate reacts to produce

  8. Synthesis, characterization, DNA binding, cleavage activity and cytotoxicity of copper(II) complexes.

    Science.gov (United States)

    Li, Mei-Jin; Lan, Tao-Yu; Cao, Xiu-Hui; Yang, Huang-Hao; Shi, Yupeng; Yi, Changqing; Chen, Guo-Nan

    2014-02-21

    Three new mononuclear copper(II) complexes, [Cu(L2)](2+) (1), [Cu(acac)(L)](+) (2), and [Cu(acac-Cl)(L)](+) (3) (L = 2-(4-pyridine)oxazo[4,5-f]1,10-phenanthroline (4-PDOP); acac = acetylacetone; acac-Cl = 3-chloroacetylacetone), have been synthesized and characterized by elemental analysis, high resolution mass spectrometry (Q-TOF), and IR spectroscopy. Two of the complexes were structurally characterized by single-crystal X-ray diffraction techniques. Their interactions with DNA were studied by UV-vis absorption and emission spectra, viscosity, thermal melting, DNA unwinding assay and CD spectroscopy. The nucleolytic cleavage activity of the compounds was carried out on double stranded pBR322 circular plasmid DNA by using a gel electrophoresis experiment in the presence and absence of an oxidant (H2O2). Active oxygen intermediates such as hydroxyl radicals and hydrogen peroxide generated in the presence of L and complexes 1-3 may act as active species for the DNA scission. The cytotoxicity of the complexes against HepG2 cancer cells was also studied.

  9. Isolation and Characterization of Bacteria Resistant to Metallic Copper Surfaces▿ †

    OpenAIRE

    Espírito Santo, Christophe; Morais, Paula Vasconcelos; Grass, Gregor

    2010-01-01

    Metallic copper alloys have recently attracted attention as a new antimicrobial weapon for areas where surface hygiene is paramount. Currently it is not understood on a molecular level how metallic copper kills microbes, but previous studies have demonstrated that a wide variety of bacteria, including Escherichia coli, Staphylococcus aureus, and Clostridium difficile, are inactivated within minutes or a few hours of exposure. In this study, we show that bacteria isolated from copper alloy coi...

  10. Construction and characterization of an azurin analog for the purple copper site in cytochrome c oxidase.

    OpenAIRE

    Hay, M; Richards, J. H.; Lu, Y.

    1996-01-01

    A protein analog of a purple copper center has been constructed from a recombinant blue copper protein (Pseudomonas aeruginosa azurin) by replacing the loop containing the three ligands to the blue copper center with the corresponding loop of the CuA center in cytochrome c oxidase (COX) from Paracoccus denitrificans. The electronic absorption in the UV and visible region (UV-vis) and electron paramagnetic resonance (EPR) spectra of this analog are remarkably similar to those of the native CuA...

  11. Metalloselenonein, the selenium analogue of metallothionein: synthesis and characterization of its complex with copper ions.

    OpenAIRE

    Oikawa, T; Esaki, N; Tanaka, H.; Soda, K

    1991-01-01

    We used an automated peptide synthesizer to produce a peptide, metalloselenonein, that contains selenocysteine residues substituted for all cysteine residues in Neurospora crassa copper metallothionein. Metalloselenonein binds 3 mol of Cu(I) per mol. This adduct shows a broad absorption band between 230 and 400 nm and a fluorescence band at 395 nm, which can be attributed to copper-selenolate coordination. The circular dichroism spectrum of the copper-metalloselenonein complex shows a positiv...

  12. Characterization of polycyclic aromatic hydrocarbons in soil close to secondary copper and aluminum smelters.

    Science.gov (United States)

    Hu, Jicheng; Wu, Jing; Zha, Xiaoshuo; Yang, Chen; Hua, Ying; Wang, Ying; Jin, Jun

    2017-04-01

    A total of 35 surface soil samples around two secondary copper smelters and one secondary aluminum smelter were collected and analyzed for 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs). The concentrations of PAHs were highest when the soil sample sites were closest to the secondary copper smelters. And, a level gradient of PAHs was observed in soil samples according to the distance from two secondary copper smelters, respectively. The results suggested that PAH concentrations in surrounding soils may be influenced by secondary copper smelters investigated, whereas no such gradient was observed in soils around the secondary aluminum smelter. Further analysis revealed that PAH patterns in soil samples also showed some difference between secondary copper and aluminum smelter, which may be attributed to the difference in their fuel and smelting process. PAH patterns and diagnostic ratios indicated that biomass burning may be also an important source of PAHs in the surrounding soil in addition to the emissions from the plants investigated.

  13. Application of chromatography and mass spectrometry to the characterization of cobalt, copper, manganese and molybdenum in Morinda citrifolia.

    Science.gov (United States)

    Rybak, Justyna; Ruzik, Lena

    2013-03-15

    An analytical procedure was proposed to determine the manganese species and to study the fractionation of microelements such as copper, cobalt and molybdenum in Noni juice. Morinda citrifolia is known as a noni fruit, Indian mulberry, nunaakai, dog dumpling, mengkudu, beach mulberry, vomit fruit and cheese fruit. It is a tropical plant with a long tradition of medicinal use in Polynesia and tropical parts of eastern Asia and Australia. This article covers the determination of manganese species in Noni juice and established by fractionation by size exclusion chromatography inductively coupled plasma mass spectrometry (SEC ICP MS) and next characterization of species by electrospray ionization mass spectrometry (ESI MS). Also presented the fractionation analysis of copper, cobalt and molybdenum in Noni juice sample using SEC ICP MS - juice was treated with buffer and enzymatic extraction media and analyzed. For the evaluation of the amounts of the metal fractions distinguished, the ICP MS was used off-line prior to the determination of copper, cobalt, molybdenum and manganese concentrations in the juice. It was established that elements are present in the analyzed samples in different species and their concentration is μg mL(-1) and ng mL(-1) range in fruit. The accuracy of the entire fractionation scheme and sample preparation procedures involved was verified by the performance of the recovery test. For the information about the bioavailability of these elements, in vitro bioavailability investigation was used by SEC ICP MS technique. Two step digestion model simulating gastric (pepsin digestion) and intestinal (pancreatin digestion) juices. In Noni juice, manganese is complexed from flavonoids - rutin, from dye like anthraquinone (alizarin) and glycosides - asperulosidic acid (ESI MS - characterization). The study shows that copper and molybdenum contained in Noni juice are complexed by peptides, and cobalt by organic acids (which are 3.6% of juice). Molybdenum in

  14. Magnetic characterization of the nickel layer protecting the copper wires in harsh applications

    Directory of Open Access Journals (Sweden)

    Roger Daniel

    2017-06-01

    Full Text Available High Temperature (HT° motor coils open new perspectives for extending the applications of electrical motors or generators to very harsh environments or for designing very high power density machines working with high internal temperature gradients. Over a temperature of 300°C, the classic enameled wire cannot work permanently, the turn-to-turn insulation must be inorganic and made with high temperature textiles or vitro-ceramic compounds. For both cases, a diffusion barrier must protect the copper wire against oxidation. The usual solution consists of adding a nickel layer that yields an excellent chemical protection. Unfortunately, the nickel has ferromagnetic properties that change a lot the skin effect in the HT wire at high frequencies. For many applications such as aeronautics, electrical machines are always associated with PWM inverters for their control. The windings must resist to high voltage short spikes caused by the fast fronted pulses imposed by the feeding inverter. The nickel protection layer of the HT° inorganic wire has a large influence on the high frequency behavior of coils and, consequently, on the magnitude of the voltage spikes. A good knowledge of the non-linear magnetic characteristics of this nickel layer is helpful for designing reliable HT inorganic coils. The paper presents a method able to characterize non-linear electromagnetic properties of this nickel layer up to 500°C.

  15. Partial purification and characterization of a copper-induced anionic peroxidase of sunflower roots.

    Science.gov (United States)

    Jouili, Hager; Bouazizi, Houda; Rossignol, Michel; Borderies, Gisèle; Jamet, Elisabeth; El Ferjani, Ezzeddine

    2008-01-01

    Treatment of 14-day-old sunflower seedlings with a toxic amount of copper (50 microM of CuSO(4)) during 5days caused significant increase in peroxidase activity in roots. Qualitative analysis of soluble proteins using native anionic PAGE followed by detection of peroxidase activity with guaïacol as electron donor in the presence of H(2)O(2) revealed five stimulated peroxidases, named A1, A2, A3, A4, and A5. These peroxidases had differential behavior during the period of treatment. A1, A2, A3 and A4 were stimulated in the first period of stress, but rapidly suppressed at 72h. A5 showed a progressive stimulation which was even increased at 120h. A1 was partially purified, identified using liquid chromatography coupled to mass spectrometry (LC-MS/MS), and characterized. Effects of pH and temperature on its activity were determined with guaïacol as electron donor. Optima were obtained at pH 8 and at 40 degrees C. Analysis of substrate specificity showed that A1 was active on coniferyl alcohol but not on IAA. Enzymatic activity was inhibited by a high concentration of H(2)O(2).

  16. Synthesis, characterization, shape evolution, and optical properties of copper sulfide hexagonal bifrustum nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Jia Baorui; Qin Mingli, E-mail: qinml@mater.ustb.edu.cn [University of Science and Technology Beijing, School of Materials Science and Engineering (China); Jiang Xuezhi [North Heavy Industry Group, Special Steel Works (China); Zhang Zili; Zhang Lin; Liu Ye; Qu Xuanhui [University of Science and Technology Beijing, School of Materials Science and Engineering (China)

    2013-03-15

    The hexagonal bifrustum-shaped copper sulfide (CuS) nanocrystals were selectively and facilely synthesized by a hydrothermal method for the first time at 120 Degree-Sign C. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, ultraviolet-visible (UV-Vis) spectroscopy, and photoluminescence spectroscopy. The results showed that the CuS hexagonal bifrustum nanocrystal was bounded by two top hexagons with edge length of about 50-70 nm and twelve lateral trapezoids with a base of about 100 nm and that the length of each hexagonal bifrustum was about 250 nm. Tetradecylamine (TDA), as an effective capping agent, was found to be critical for this special shape. Using different amounts of TDA, two kinds of CuS hexagonal bifrustum nanocrystals were obtained: 'lender hexagonal bifrustum' and 'pancake hexagonal bifrustum.' Furthermore, we studied the formation mechanism of hexagonal bifrustum, which is related to the intrinsic crystalline structure of CuS and Ostwald ripening. And, the results revealed that the CuS nanocrystal evolved from hexagonal plate to hexagonal bifrustum and finally to hexagonal bipyramid as the heating time increased. The UV-Vis absorption spectrum showed that these CuS hexagonal bifrustum nanocrystals exhibited strong absorption in the near-infrared region and had a potential application for photothermal therapy and photocatalysis.

  17. Development and physicochemical characterization of copper complexes-loaded PLGA nanoparticles.

    Science.gov (United States)

    Courant, T; Roullin, V G; Cadiou, C; Delavoie, F; Molinari, M; Andry, M C; Chuburu, F

    2009-09-11

    PLGA nanoparticles were prepared via a modified W/O/W emulsion solvent diffusion process, in which all formulation components were fully biocompatible and biodegradable. Different independent processing parameters were systematically studied. Nanoparticles were characterized by DLS (particle size, polydispersity, zeta-potential) and TEM/AFM (surface morphology). An optimized formulation was used to encapsulate copper complexes of cyclen and DOTA as potential PET imaging agents. Results showed that the predominant formulation factors appeared to be the lactide-to-glycolide (L:G) ratio of PLGA, the nature of the diffusion phase, and the presence of hydroxyl ions in the first-emulsion aqueous phase. By regulating those 3 parameters, PLGA nanoparticles were prepared with very good preparation yields (>95%), a size less than 200 nm and a polydispersity index less than 0.1. TEM pictures showed nanoparticles with a narrow size distribution, a spherical shape and a smooth surface. The optimized formulation allowed to encapsulate Cu-cyclen and Cu-DOTA complexes with an encapsulation efficiency between 20% and 25%.

  18. Fabrication and characterization of Y{sub 2}O{sub 3} dispersion strengthened copper alloys

    Energy Technology Data Exchange (ETDEWEB)

    Carro, G.; Muñoz, A. [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Monge, M.A., E-mail: mmonge@fis.uc3m.es [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Savoini, B.; Pareja, R.; Ballesteros, C. [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Adeva, P. [Centro Nacional de Investigaciones Metalúrgicas, CSIC, Av. Gregorio del Amo, 8, 28040 Madrid (Spain)

    2014-12-15

    Three copper base materials were fabricated following different routes: cast Cu–1 wt.%Y (C-Cu1Y) produced by vacuum induction melting, and Cu–1 wt.%Y (PM-Cu1Y) and Cu–1 wt.%Y{sub 2}O{sub 3} (PM-Cu1Y{sub 2}O{sub 3}) both processed by a powder metallurgy route and sintering by hot isostatic pressing. PM-Cu1Y alloy was prepared by cryomilling and PM-Cu1Y{sub 2}O{sub 3} by conventional milling at room temperature. The materials were characterized by X-ray diffraction, optical and electron microscopy and microhardness measurements. C-Cu1Y presents a characteristic eutectic microstructure while PM-Cu1Y{sub 2}O{sub 3} exhibits a composite like microstructure. Electron microscopy analyses of as-HIP PM-Cu1Y revealed irregular decoration of yttrium-rich oxides at the grain boundaries and an inhomogeneous dispersion of polygonal shaped yttrium-rich oxides dispersed in the Cu matrix. Tensile tests performed on PM-Cu–1Y on the temperature range of 293–773 K have showed a decrease of the yield strength at temperatures higher than 473 K, and monotonically decrease of the ultimate tensile strength and maximum plastic strain on increasing temperature.

  19. Characterization of a “Smart” Hybrid Varnish Electrospun Nylon Benzotriazole Copper Corrosion Protection Coating

    Directory of Open Access Journals (Sweden)

    C. Menchaca

    2012-01-01

    Full Text Available This work presents the electrochemical evaluation of a proposed copper corrosion protection hybrid coating acting as a smart corrosion protection system. This consists of an alkyd varnish, painted over electrospun nylon fibers acting as a secondary diffusion barrier and also as a benzotriazole (BTAH inhibitor nanocontainer. Submicron diameter electrospun nylon 6-6 fiber nanocontainers were prepared from a polymeric solution containing BTAH at different concentrations, and Cu samples were coated with the electrospun fibers and painted over with an alkyd varnish by the drop method. Functional groups in fibers were determined through FTIR spectroscopy. Optical and SEM microscopies were used to characterize the nanocontainer fibers. Samples were evaluated using electrochemical impedance and noise, during six weeks of immersion, in a chloride-ammonium sulfate solution. Excellent response was obtained for the smart inhibitor coating system. For long periods of immersion good corrosion protection performance was observed. The results presented demonstrate the good barrier properties of the hybrid coating, obstructing the diffusion of aggressive species, through the electrospun structure. Furthermore the nanocontainer functionality to store and liberate the corrosion inhibitor, only when it is needed, was also proved.

  20. Blue copper protein analogue: synthesis and characterization of copper complexes of the N2S2 macrocycle 1,8-dithia-4,11-diazacyclotetradecane.

    Science.gov (United States)

    Walker, Tia L; Mula, Sam; Malasi, Wilhelm; Engle, James T; Ziegler, Christopher J; van der Est, Art; Modarelli, Jody; Taschner, Michael J

    2015-12-14

    To improve understanding of copper at the active site of Type 1 copper proteins, Cu(I) and Cu(II) complexes of 1,8-dithia-4,11-diazacyclotetradecane, shown in , have been successfully isolated and structurally characterized by X-ray crystallography. In these compounds, both Cu(I) and Cu(II) are centered in the plane of the macrocycle containing two sulphur and two nitrogen heteroatoms comprising the distorted tetrahedral/square planar coordination geometry. The UV/VIS spectra, electrochemistry and EPR properties have been obtained for the Cu(II) complex 2. Three absorption bands at 295 nm, 354 nm, and 545 nm are observed in aqueous solution at a pH of 5. These bands have been assigned to the N → Cu(II) and S → Cu(II) charge transfer bands and the d-d transitions respectively. The Cu(I/II) redox midpoint potential of complex 2 in CH3CN is +403 mV versus NHE.

  1. Pseudohalide copper(II) complexes derived from polypyridyl ligands: Synthesis and characterization

    Science.gov (United States)

    Mautner, Franz A.; Louka, Febee R.; LeGuet, Thibaut; Massoud, Salah S.

    2009-02-01

    A novel series of pseudohalide- ( N3- NCS -) and perchlorato-Cu(II) complexes possessing a series of ligands with pyridyl-containing donors have been investigated. These include [Cu(pmap)ClO 4)]ClO 4 ( 1), [Cu(pmap)(N 3)]ClO 4 ( 2), [Cu(pmea)(N 3)]ClO 4·H 2O ( 3), [Cu(dp-pa)(N 3)]ClO 4·½H 2O ( 4), [Cu(pzdepy)ClO 4]ClO 4 ( 5), [Cu(pzdepy)(NCS)]ClO 4 ( 6) and [Cu 2(L)(NCS) 4]·2CH 3CN ( 7) where pmap = bis[2-(2-pyridylethyl)]-(2-pyridylmethyl)amine, pmea = bis(2-pyridylmethyl)-2-(2-pyridylethyl)amine, dp-pa = N-propanamide- N, N-bis(2-pyridylmethyl)amine, pzdepy = N, N'-bis[2-(2-pyridylethyl)]piperazine and L = 3,5-bis[bis(2-pyridylmethyl)aminomethyl]-toluene. All complexes were characterized by elemental analyses, IR and UV-Visible spectroscopy. The visible spectra of all complexes reveal the square-pyramidal geometries (SP) around the central Cu 2+ ion. IR spectra confirmed the coordination of the ClO4- group in 1 and 5 and the N-donor thiocyanate group in complexes 6 and 7. The X-ray structure determination of the pseudohalide complexes 2, 6 and 7 confirmed the monodentate coordination nature of N3- and NCS - ions. The structure of 2 or 6 consists of isolated [Cu(pmap)(N 3)] + or [Cu(pzdepy)(NCS)] + cations and perchlorate counter anions. The copper centers are penta-coordinated by the four N atoms of the pmap or pzdepy and N(5) atom of the azide group in 2 and the thiocyanate group in 6. In the dinuclear unit [Cu 2(L)(NCS) 4] of 7, each copper atom forms bonds to three nitrogen atoms of the ligand L, [Cu sbnd N bonds from 2.013(2) to 2.054(2) Å], and to N(4) and N(5) atoms of the two terminal thiocyanato groups [Cu(1) sbnd N(4) = 1.954(2) Å; Cu(1) sbnd N(5) = 2.178(2) Å]. The intradimer Cu(1)...Cu(1A) distance is 5.7010(14) Å. An intramolecular π-π stacking with a ring-ring separation of 3.5991(14) Å is observed between the central benzene ring and the pyridyl rings. In the three complexes ( 2, 6 and 7), the CuN 5 chromophore may be described as an

  2. Effect of copper on the characterization of proteins in the Spiny lobster, Panulirus homarus homarus (Linnaeus,1758

    Directory of Open Access Journals (Sweden)

    Maharajan Athisuyambulingam

    2014-07-01

    Full Text Available Copper is most toxic metal in marine organisms. Characterization of protein occurring in the metabolically active tissues of muscle (MU, hepatopancreas (HP and gills (GL of the spiny lobster, Panulirus homarus homarus on exposure to two sub-lethal doses (9.55 and 19.1 µg/l of copper were studied for 28 days of exposure (DoE. The electrophoretic pattern of muscle, hepatopancreas and gill proteins revealed 12, 8 and 8 slow moving bands (control. The number of bands decreased to 8 and 7, 6 and 5, 6 and 4 after 7 days of exposure to 9.55 µg/l and 19.1 µg/l concentrations of copper, respectively. After 28 days, the protein bands decreased to 7 and 6, 5 and 4, 4 and 4 at 9.55 µg/l and 19.1 µg/l concentrations of copper, respectively. Present study to indicate that to avoid the Cupro-Nickel coil in lobster holding centers in chiller plants used for cooling of water was found to be responsible for the mortality of lobsters during live transportation.

  3. Synthesis, characterization and DNA interaction of new copper(II) complexes of Schiff base-aroylhydrazones bearing naphthalene ring.

    Science.gov (United States)

    Gökçe, Cansu; Gup, Ramazan

    2013-05-05

    Two new copper(II) complexes with the condensation products of methyl 2-naphthyl ketone with 4-hydroxybenzohydrazide, 4-hydroxy-N'-[(1Z)-1-(naphthalen-2-yl)ethylidene]benzohydrazide [HL(1)] and (Z)-ethyl 2-(4-(2-(1-(naphthalen-2-yl)ethylidene)hydrazinecarbonyl)phenoxy)acetate (HL(2)) were synthesized and characterized by elemental analysis, infrared spectra, UV-Vis electronic absorption spectra, magnetic susceptibility measurements, TGA, powder XRD and SEM-EDS. The binding properties of the copper(II) complexes with calf thymus DNA were studied by using the absorption titration method. DNA cleavage activities of the synthesized copper complexes were examined by using agarose gel electrophoresis. The effect of complex concentration on the DNA cleavage reactions in the absence and presence of H2O2 was also investigated. The experimental results suggest that the copper complexes bind significantly to calf thymus DNA by both groove binding and intercalation modes and cleavage effectively pBR322 DNA. The mechanistic studies demonstrate that a hydrogen peroxide-derived species and singlet oxygen ((1)O2) are the active oxidative species for DNA cleavage.

  4. Construction and characterization of an azurin analog for the purple copper site in cytochrome c oxidase.

    Science.gov (United States)

    Hay, M; Richards, J H; Lu, Y

    1996-01-09

    A protein analog of a purple copper center has been constructed from a recombinant blue copper protein (Pseudomonas aeruginosa azurin) by replacing the loop containing the three ligands to the blue copper center with the corresponding loop of the CuA center in cytochrome c oxidase (COX) from Paracoccus denitrificans. The electronic absorption in the UV and visible region (UV-vis) and electron paramagnetic resonance (EPR) spectra of this analog are remarkably similar to those of the native CuA center in COX from Paracoccus denitrificans. The above spectra can be obtained upon addition of a mixture of Cu2+ and Cu+. Addition of Cu2+ only results in a UV-vis spectrum consisting of absorptions from both a purple copper center and a blue copper center. This spectrum can be converted to the spectrum of a pure purple copper by a prolonged incubation in the air, or by addition of excess ascorbate. The azurin mutant reported here is an example of an engineered purple copper center with the A480/A530 ratio greater than 1 and with no detectable hyperfines, similar to those of the CuA sites in COX of bovine heart and of Paracoccus denitrificans.

  5. Metalloselenonein, the selenium analogue of metallothionein: synthesis and characterization of its complex with copper ions.

    Science.gov (United States)

    Oikawa, T; Esaki, N; Tanaka, H; Soda, K

    1991-01-01

    We used an automated peptide synthesizer to produce a peptide, metalloselenonein, that contains selenocysteine residues substituted for all cysteine residues in Neurospora crassa copper metallothionein. Metalloselenonein binds 3 mol of Cu(I) per mol. This adduct shows a broad absorption band between 230 and 400 nm and a fluorescence band at 395 nm, which can be attributed to copper-selenolate coordination. The circular dichroism spectrum of the copper-metalloselenonein complex shows a positive band around 245 nm attributable to asymmetry in metal coordination. PMID:1826562

  6. Characterization of post-copper CMP surfaces with scanning probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dominget, A. [Freescale Semiconductor, Crolles2 Alliance, 870 Rue Jean Monnet, 38926 Crolles (France); Farkas, J. [Freescale Semiconductor, Crolles2 Alliance, 870 Rue Jean Monnet, 38926 Crolles (France)]. E-mail: Janos.Farkas@freescale.com; Szunerits, S. [Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces (LEPMI), CNRS-INPG-UJF, 1130 Rue de la Piscine, BP 75, 38402 St. Martin d' Heres (France)]. E-mail: sabine.szunerits@lepmi.inpg.fr

    2006-09-15

    We demonstrate in this paper for the first time the use of conductive atomic force microscopy (AFM) to measure surface leakage between copper structures with varying line width and spacing in the micro and sub micrometer ranges. Conducting atomic force microscopy allows subsequent measurement of the topography as well as the electrical properties of surfaces. The feasibility and interest of these measurements will be shown by studying the impact of chemical mechanical polishing (CMP) of an electrical interface bearing different micrometric copper structures. As expected the polishing time has a crucial impact on the current determined between closely spaced copper structures. This paper will also deal with issues observed during the measurement.

  7. Synthesis, structural characterization and cytotoxic activity of ternary copper(II)-dipeptide-phenanthroline complexes. A step towards the development of new copper compounds for the treatment of cancer.

    Science.gov (United States)

    Iglesias, Sebastián; Alvarez, Natalia; Torre, María H; Kremer, Eduardo; Ellena, Javier; Ribeiro, Ronny R; Barroso, Rafael P; Costa-Filho, Antonio J; Kramer, M Gabriela; Facchin, Gianella

    2014-10-01

    In the search for new compounds with antitumor activity, coordination complexes with different metals are being studied by our group. This work presents the synthesis and characterization of six copper complexes with general stoichiometry [Cu(L-dipeptide)(phen)]·nH2O (were phen=1,10-phenanthroline) and their cytotoxic activities against tumor cell lines. To characterize these systems, analytical and spectroscopic studies were performed in solid state (by UV-visible, IR, X-ray diffraction) including the crystal structure of four new complexes (of the six complexes studied): [Cu(Ala-Phe)(phen)]·4H2O, [Cu(Phe-Ala)(phen)]·4H2O, [Cu(Phe-Val)(phen)]·4.5H2O and [Cu(Phe-Phe)(phen)]·3H2O. In all of them, the copper ion is situated in a distorted squared pyramidal environment. The phen ligand is perpendicular to the dipeptide, therefore exposed and potentially available for interaction with biological molecules. In addition, for all the studied complexes, structural information in solution using EPR and UV-visible spectroscopies were obtained, showing that the coordination observed in solid state is maintained. The lipophilicity, DNA binding and albumin interaction were also studied. Biological experiments showed that all the complexes induce cell death in the cell lines: HeLa (human cervical adenocarcinoma), MCF-7 (human metastatic breast adenocarcinoma) and A549 (human lung epithelial carcinoma). Among the six complexes, [Cu(Ala-Phe)(phen)] presents the lowest IC50 values. Taken together all these data we hypothesize that [Cu(Ala-Phe)(phen)] may be a good candidate for further studies in vivo.

  8. Friction Stir Welds (FSW of aluminium alloy AW6082-T6

    Directory of Open Access Journals (Sweden)

    J. Adamowski

    2007-01-01

    Full Text Available Purpose: Purpose of this paper is the investigation on the properties and microstructural changes in Friction StirWelds in the aluminum alloy 6082-T6 in function of varying process parameters.Design/methodology/approach: Tensile strength of the produced joints was tested and the correlation withprocess parameter was assessed. Microstructures of various zones of FSW welds are presented and analyzed bymeans of optical microscopy and microhardness measurements.Findings: Mechanical resistance of test welds increased with the increase of travel (welding speed withconstant rotational speed. Softening of the material in weld nugget and heat affected zone was observed, ofentity inferior that that of fusion welds. Origin of tunnel (worm hole defects were found and analyzed.Research limitations/implications: The test welds were produced with various combinations of processparameters without the possibility of controlling the downward force. Further extension of applicable parameterscombinations could be examined.Practical implications: The increase of mechanical resistance with increasing welding speed offers animmediate economic return, as the process efficiency is increased.Originality/value: Information contained herein can be useful to further investigate on the possibility ofimproving the properties of FSW welds, as well as the efficiency of the process.

  9. Complexation and Toxicity of Copper in Higher Plants. I. Characterization of Copper Accumulation, Speciation, and Toxicity in Crassula helmsii as a New Copper Accumulator1[W][OA

    Science.gov (United States)

    Küpper, Hendrik; Götz, Birgit; Mijovilovich, Ana; Küpper, Frithjof C.; Meyer-Klaucke, Wolfram

    2009-01-01

    The amphibious water plant Crassula helmsii is an invasive copper (Cu)-tolerant neophyte in Europe. It now turned out to accumulate Cu up to more than 9,000 ppm in its shoots at 10 μm (=0.6 ppm) Cu2+ in the nutrient solution, indicating that it is a Cu hyperaccumulator. We investigated uptake, binding environment, and toxicity of Cu in this plant under emerged and submerged conditions. Extended x-ray absorption fine structure measurements on frozen-hydrated samples revealed that Cu was bound almost exclusively by oxygen ligands, likely organic acids, and not any sulfur ligands. Despite significant differences in photosynthesis biochemistry and biophysics between emerged and submerged plants, no differences in Cu ligands were found. While measurements of tissue pH confirmed the diurnal acid cycle typical for Crassulacean acid metabolism, Δ13C measurements showed values typical for regular C3 photosynthesis. Cu-induced inhibition of photosynthesis mainly affected the photosystem II (PSII) reaction center, but with some unusual features. Most obviously, the degree of light saturation of electron transport increased during Cu stress, while maximal dark-adapted PSII quantum yield did not change and light-adapted quantum yield of PSII photochemistry decreased particularly in the first 50 s after onset of actinic irradiance. This combination of changes, which were strongest in submerged cultures, shows a decreasing number of functional reaction centers relative to the antenna in a system with high antenna connectivity. Nonphotochemical quenching, in contrast, was modified by Cu mainly in emerged cultures. Pigment concentrations in stressed plants strongly decreased, but no changes in their ratios occurred, indicating that cells either survived intact or died and bleached quickly. PMID:19641032

  10. Complexation and toxicity of copper in higher plants. I. Characterization of copper accumulation, speciation, and toxicity in Crassula helmsii as a new copper accumulator.

    Science.gov (United States)

    Küpper, Hendrik; Götz, Birgit; Mijovilovich, Ana; Küpper, Frithjof C; Meyer-Klaucke, Wolfram

    2009-10-01

    The amphibious water plant Crassula helmsii is an invasive copper (Cu)-tolerant neophyte in Europe. It now turned out to accumulate Cu up to more than 9,000 ppm in its shoots at 10 microm (=0.6 ppm) Cu(2+) in the nutrient solution, indicating that it is a Cu hyperaccumulator. We investigated uptake, binding environment, and toxicity of Cu in this plant under emerged and submerged conditions. Extended x-ray absorption fine structure measurements on frozen-hydrated samples revealed that Cu was bound almost exclusively by oxygen ligands, likely organic acids, and not any sulfur ligands. Despite significant differences in photosynthesis biochemistry and biophysics between emerged and submerged plants, no differences in Cu ligands were found. While measurements of tissue pH confirmed the diurnal acid cycle typical for Crassulacean acid metabolism, Delta(13)C measurements showed values typical for regular C3 photosynthesis. Cu-induced inhibition of photosynthesis mainly affected the photosystem II (PSII) reaction center, but with some unusual features. Most obviously, the degree of light saturation of electron transport increased during Cu stress, while maximal dark-adapted PSII quantum yield did not change and light-adapted quantum yield of PSII photochemistry decreased particularly in the first 50 s after onset of actinic irradiance. This combination of changes, which were strongest in submerged cultures, shows a decreasing number of functional reaction centers relative to the antenna in a system with high antenna connectivity. Nonphotochemical quenching, in contrast, was modified by Cu mainly in emerged cultures. Pigment concentrations in stressed plants strongly decreased, but no changes in their ratios occurred, indicating that cells either survived intact or died and bleached quickly.

  11. Characterization of single phase copper selenide nanoparticles and their growth mechanism

    Science.gov (United States)

    Patidar, D.; Saxena, N. S.

    2012-03-01

    The high quality Cu3Se2 phase of copper selenide nanoparticles was synthesized through the solution-phase chemical reaction between copper and selenium. In this synthesis process, hydrazine hydrate acts as reducing agent whereas ethylene glycol controls the nucleation and growth of particles. An effort has been made to explain the growth mechanism to form copper selenide nanoparticles through the coordination of selenium to the Cu2+ complexes with OH groups of ethylene glycol. Result indicates the formation of Cu3Se2 single phase nanoparticles. The particles with the average particle size 25 nm are spherical in shape having tetragonal structure. The particles are well crystallized having 94% degree of crystallinity. An effort has also been made to determine the energy band gap of copper selenide nanoparticles through the absorption spectra.

  12. Characterization and control of the microbial community affiliated with copper or aluminum heat exchangers of HVAC systems.

    Science.gov (United States)

    Schmidt, Michael G; Attaway, Hubert H; Terzieva, Silva; Marshall, Anna; Steed, Lisa L; Salzberg, Deborah; Hamoodi, Hameed A; Khan, Jamil A; Feigley, Charles E; Michels, Harold T

    2012-08-01

    Microbial growth in heating ventilation and air-conditioning (HVAC) systems with the subsequent contamination of indoor air is of increasing concern. Microbes and the subsequent biofilms grow easily within heat exchangers. A comparative study where heat exchangers fabricated from antimicrobial copper were evaluated for their ability to limit microbial growth was conducted using a full-scale HVAC system under conditions of normal flow rates using single-pass outside air. Resident bacterial and fungal populations were quantitatively assessed by removing triplicate sets of coupons from each exchanger commencing the fourth week after their installation for the next 30 weeks. The intrinsic biofilm associated with each coupon was extracted and characterized using selective and differential media. The predominant organisms isolated from aluminum exchangers were species of Methylobacterium of which at least three colony morphologies and 11 distinct PFGE patterns we found; of the few bacteria isolated from the copper exchangers, the majority were species of Bacillus. The concentrations and type of bacteria recovered from the control, aluminum, exchangers were found to be dependent on the type of plating media used and were 11,411-47,257 CFU cm(-2) per coupon surface. The concentration of fungi was found to average 378 CFU cm(-2). Significantly lower concentrations of bacteria, 3 CFU cm(-2), and fungi, 1 CFU cm(-2), were recovered from copper exchangers regardless of the plating media used. Commonly used aluminum heat exchangers developed stable, mixed, bacterial/fungal biofilms in excess of 47,000 organisms per cm(2) within 4 weeks of operation, whereas the antimicrobial properties of metallic copper were able to limit the microbial load affiliated with the copper heat exchangers to levels 99.97 % lower during the same time period.

  13. One-pot synthesis and characterization of subnanometre-size benzotriazolate protected copper clusters.

    Science.gov (United States)

    Salorinne, Kirsi; Chen, Xi; Troff, Ralf W; Nissinen, Maija; Häkkinen, Hannu

    2012-07-21

    A simple one-pot method for the preparation of subnanometre-size benzotriazolate (BTA) protected copper clusters, Cu(n)BTA(m), is reported. The clusters were analyzed by optical and infrared spectroscopy, mass spectrometry and transmission electron microscopy together with computational methods. We suggest a structural motif where the copper core of the Cu(n)BTA(m) clusters is protected by BTA-Cu(i)-BTA units.

  14. Preparation, characterization and toxicological investigation of copper loaded chitosan nanoparticles in human embryonic kidney HEK-293 cells

    Energy Technology Data Exchange (ETDEWEB)

    Arora, Divya [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Formulation and Drug Delivery Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Dhanwal, Vandna [Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Nayak, Debasis [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Saneja, Ankit [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Formulation and Drug Delivery Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Amin, Hina [Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Rasool, Reyaz ur [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Gupta, Prem Narayan [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Formulation and Drug Delivery Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Goswami, Anindya, E-mail: agoswami@iiim.ac.in [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India)

    2016-04-01

    Metallic nanoparticles often attribute severe adverse effects to the various organs or tissues at the molecular level despite of their applications in medical, laboratory and industrial sectors. The present study highlights the preparation of copper adsorbed chitosan nanoparticles (CuCSNPs), its characterization and validation of cytotoxicity in human embryonic kidney HEK-293 cells. Particle size of the CuCSNPs was determined by using Zetasizer and the copper loading was quantified with the help of ICP/MS. Further characterization of CuCSNPs was carried out by FT-IR analysis to determine the formation of nanoparticles and SEM was conducted for the morphological analysis of the CuCSNPs. The CuCSNPs exhibited pronounced cytotoxic effects towards HEK-293 cells as analyzed by MTT assay. Moreover, the CuCSNPs inhibited the colony formation and induced nuclear damage at the dose of 100 μg/mL, much more effectively than the in built control copper sulfate (CuSO{sub 4}). At the molecular level, the CuCSNPs were found to be triggering reactive oxygen species (ROS), activating effector caspases and subsequent PARP cleavage to induce cell death in HEK-293 cells. - Highlights: • Subtoxic levels of CuCSNPs induce apoptosis in HEK-293 cells. • CuCSNPs mediate toxicity via nuclear cleavage and ROS generation. • CuCSNPs favor caspase activation and PARP cleavage to induce cell death.

  15. Effect of aging on copper nanoparticles synthesized by pulsed laser ablation in water: structural and optical characterizations

    Indian Academy of Sciences (India)

    R K Swarnkar; S C Singh; R Gopal

    2011-12-01

    Effect of aging on copper nanoparticles synthesized by pulsed laser ablation of copper plate in water was studied. By characterization studies of the aged nanoparticles, it is found that copper nanoparticles converted into Cu@Cu2O nanostructure. The synthesized nanomaterial is characterized with UV-Visible absorption, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman and photoluminescence (PL) spectroscopic techniques. TEM image shows that the aged nanoparticles get assembled into cactus like structure and are spherical in shape with average diameter 7 nm and dispersion 2 nm. XRD and FTIR spectrum confirm the formation of Cu@Cu2O in the aged sample. Raman spectrum also confirms the presence of Cu2O nanoparticles. PL spectrum of the aged nanoparticles shows a direct allowed transition with bandgap energy of 2.24 eV. The mechanism for synthesis of core-shell nanoparticles and formation of self-assembly of nanoparticles is also discussed.

  16. Preparation, characterization and toxicological investigation of copper loaded chitosan nanoparticles in human embryonic kidney HEK-293 cells.

    Science.gov (United States)

    Arora, Divya; Dhanwal, Vandna; Nayak, Debasis; Saneja, Ankit; Amin, Hina; Ur Rasool, Reyaz; Gupta, Prem Narayan; Goswami, Anindya

    2016-04-01

    Metallic nanoparticles often attribute severe adverse effects to the various organs or tissues at the molecular level despite of their applications in medical, laboratory and industrial sectors. The present study highlights the preparation of copper adsorbed chitosan nanoparticles (CuCSNPs), its characterization and validation of cytotoxicity in human embryonic kidney HEK-293 cells. Particle size of the CuCSNPs was determined by using Zetasizer and the copper loading was quantified with the help of ICP/MS. Further characterization of CuCSNPs was carried out by FT-IR analysis to determine the formation of nanoparticles and SEM was conducted for the morphological analysis of the CuCSNPs. The CuCSNPs exhibited pronounced cytotoxic effects towards HEK-293 cells as analyzed by MTT assay. Moreover, the CuCSNPs inhibited the colony formation and induced nuclear damage at the dose of 100 μg/mL, much more effectively than the in built control copper sulfate (CuSO4). At the molecular level, the CuCSNPs were found to be triggering reactive oxygen species (ROS), activating effector caspases and subsequent PARP cleavage to induce cell death in HEK-293 cells. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Characterization of new specific copper chelators as potential drugs for the treatment of Alzheimer's disease.

    Science.gov (United States)

    Nguyen, Michel; Robert, Anne; Sournia-Saquet, Alix; Vendier, Laure; Meunier, Bernard

    2014-05-26

    The non-controlled redox-active metal ions, especially copper, in the brain of patients with Alzheimer disease (AD) should be considered at the origin of the intense oxidative damage in the AD brain. Several bis(8-aminoquinoline) ligands, such as 1 and PA1637, are able to chelate Cu(2+) with high affinity, and are specific chelators of copper with respect to iron and zinc. They are able to efficiently extract Cu(2+) from a metal-loaded amyloid. In addition, these tetradentate ligands are specific for the chelation of Cu(2+) compared with Cu(+). Consequently, the copper ion is easily released from the bis(8-aminoquinoline) ligand under reductive conditions, and can be trapped again by a protein having some affinity for copper such as human serum albumin (HSA) proteins. In addition, the copper is not efficiently released from [Cu(CQ)2] in reductive conditions. The catalytic production of H2O2 by [Cu(2+)-Aβ(1-28)]/ascorbate is inhibited in vitro by the bis(8-aminoquinoline) 1, suggesting that 1 should be able to play a protective role against oxidative damages induced by copper-loaded amyloids.

  18. Fabrication and Characterization of Copper-Based Nanoparticles for Transparent Solar Cell Applications.

    Science.gov (United States)

    Yoon, Hoi Jin; Bang, Ki Su; Lee, Seung-Yun

    2015-10-01

    This paper reports on the fabrication of copper-based nanoparticles using microemulsions, and their optical properties for use in transparent solar cell applications. Microemulsions, containing pure copper nanoparticles, were prepared using the reaction process of CuCl2 with KBH4. We have confirmed that various sized copper nanoparticles, with a radius of up to 10 nm, form within an aqueous concentration of CuCl2 ≤ 2.0 M. Using microstructural observation, we found that parts of pure copper nanoparticles, synthesized in microemulsions, oxidize into cuprous oxide and agglomerate with one another in a normal atmosphere. The copper-based particles were then transferred to substrates by using a spin-coating process. Variations in spin speed led to significant changes in the transmittance and reflectance of the spin-coated particles. Transparent and anti-reflective properties of the particles were obtained at an optimum condition of spin speed. This suggests that the fabrication of the copper-based nanoparticles can be effectively applied to the manufacturing of transparent solar cells.

  19. Synthesis, characterization, antibacterial activity, SOD mimic and interaction with DNA of drug based copper(II) complexes

    Science.gov (United States)

    Patel, Mohan N.; Dosi, Promise A.; Bhatt, Bhupesh S.; Thakkar, Vasudev R.

    2011-02-01

    Novel metal complexes of the second-generation quinolone antibacterial agent enrofloxacin with copper(II) and neutral bidentate ligands have been prepared and characterized with elemental analysis reflectance, IR and mass spectroscopy. Complexes have been screened for their in-vitro antibacterial activity against two Gram (+ve)Staphylococcus aureus, Bacillus subtilis, and three Gram (-ve)Serratia marcescens, Escherichia coli and Pseudomonas aeruginosa organisms using the double dilution technique. The binding of this complex with CT-DNA has been investigated by absorption titration, salt effect and viscosity measurements. Binding constant is ranging from 1.3 × 10 4-3.7 × 10 4. The cleavage ability of complexes has been assessed by gel electrophoresis using pUC19 DNA. The catalytic activity of the copper(II) complexes towards the superoxide anion (O 2rad -) dismutation was assayed by their ability to inhibit the reduction of nitroblue tetrazolium (NBT).

  20. Influence of Friction Stir Welding (FSW) on Mechanical and Corrosion Properties of AW-7020M and Aw-7020 Alloys

    OpenAIRE

    Dudzik Krzysztof; Jurczak Wojciech

    2016-01-01

    Friction welding associated with mixing the weld material (FSW - Friction Stir Welding ) is an alternative to MIG and TIG welding techniques for Al-alloys. This paper presents experimental results obtained from static tension tests on specimens made of AW-7020M and AW-7020 alloys and their joints welded by using FSW method carried out on flat specimens, according to Polish standards : PN-EN ISO 4136:2011 and PN-EN ISO 6892-1:2010. Results of corrosion resistance tests are also presented. The ...

  1. Démarche pour le choix et/ou la conception d'un moyen de soudage par FSW

    OpenAIRE

    ZIMMER-CHEVRET, Sandra; LANGLOIS, Laurent; LAYE, Julien; Goussain, Jean-Claude; Martin, Patrick; Bigot, Régis

    2009-01-01

    National audience; Les travaux de recherches présentés concernent l'industrialisation du procédé de soudage par friction malaxage, également appelé Friction Stir Welding (FSW). L'objectif est de fournir des outils aux industriels pour choisir et qualifier une machine pour leurs applications de FSW. Cet article présente une méthodologie pour qualifier et / ou concevoir les moyens de soudage adaptés à une application donnée. La démarche de qualification repose sur l'étude géométrique des pièces...

  2. Crystal structure, characterization and magnetic properties of a 1D copper(II) polymer incorporating a Schiff base with carboxylate side arm

    Indian Academy of Sciences (India)

    SHYAMAPADA SHIT; MADHUSUDAN NANDY; CORRADO RIZZOLI; CÉDRIC DESPLANCHES; SAMIRAN MITRA

    2016-06-01

    A new 1D polymeric copper(II) complex [{Cu(L)$(CF_{3}COO)}2]_{n}$ has been synthesized using apotentially tetradentate Schiff base ligand, HL, ((E)-2-((pyridin-2-yl)methyleneamino)-5-chlorobenzoic acid)and characterized by different spectroscopic methods. Single crystal X-ray structural characterization revealsthat the side arm carboxylate group of the coordinated Schiff base exhibits a $μ_{1,3}$ -bridging mode and connectsthe neighbouring copper(II) ions leading to a zigzag 1D chain structure where the copper(II) ions displaydistorted square pyramidal geometries. Variable temperature magnetic susceptibility measurement reveals aweak antiferromagnetic exchange (J = −0.47±0.01 $cm_{−1}) prevails between copper(II) ions in the chainmediated by the bridging carboxylate group, is also supported by the room temperature EPR spectral study.Electrochemical property of the complex is also reported.

  3. Characterization of copper-resistant agrobacterium isolated from legume nodule in mining tailings.

    Science.gov (United States)

    Yu, Jianfu; Fan, Lianmei; Yang, Shushen; Tang, Ming; Yang, Wenquan; Li, Huifen; Wei, Gehong

    2009-03-01

    A copper-resistant bacteria CCNWSX2332 was isolated from root nodules of Lespedeza cuneata growing in a gold mining tailing region in northwest of China. The specific growth rate of the strain was 0.62 microh(-1) in the presence of 2.0 mM Cu(2+) in TY liquid media, and the maximum copper accumulation of whole cell reached 147.03 microM Cu(2+) per gram (dry weight) after 4 h incubation. A partial sequence of the copper resistance gene copA was amplified from the strain, and the phylogenetic analysis based on 16S rDNA sequence showed that CCNWSX2332 belonged to Agrobacterium, and it had 100% similarity with Agrobacterium tumefaciens type strain IAM13129(T).

  4. 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.

  5. Preparation and characterization of silicone rubber/nano-copper nanocomposites for use in intrauterine devices.

    Science.gov (United States)

    Chen, Yongjun; Luo, Yuanfang; Jia, Zhixin; Jia, Demin; Chen, Juan

    2014-01-01

    In this work, a novel silicone rubber/nano-copper nanocomposite for use in intrauterine devices (IUDs) was developed. Moreover, the release rate of Cu2+ ions and the water absorption of the prepared nanocomposite were investigated in detail. The results indicate that the release rate of Cu2+ ions and water absorption capability of the silicone rubber/nanocopper nanocomposite increase as the nano-copper content increases. SEM analysis suggested there is a uniform dispersion of nano-copper in the silicone matrix. Further, systematic analysis indicated that the release rate of Cu2+ ions in the prepared nanocomposite-based IUD can be stabilized for months, which is not possible in the case of traditional IUDs.

  6. Preparation and characterization of molybdenum powders with copper coating by the electroless plating technique

    Institute of Scientific and Technical Information of China (English)

    WANG Guangjun; WANG Dezhi

    2008-01-01

    Molybdenum powders with a diameter of approximately 3 μm were coated with copper using the electroless plating technique in the pH 12.5-13 and temperature range of 55-75℃.The optimization of the electroless copper bath was evaluated through the combination of process parameters like pH and temperature.The optimized values of pH and temperature were found to be 12.5 and 60℃,respectively,which attributes to the bright maroon color of the coating with an increase in weight of 46%.The uncoated and coated powders were subjected to microstructural studies using scanning electron microscope (SEM) and the phases were analyzed using X-ray diffraction (XRD).An attempt was made to understand the growth mechanism of the coating.The diffusion-shrinkage autocatalytic model was suggested for copper growth on the molybdenum surface.

  7. Physico-chemical characterization and anti- microbial activity of copper(II complexes with 2-amino and 2-methylbenzimidazole derivatives

    Directory of Open Access Journals (Sweden)

    Podunavac-Kuzmanović Sanja O.

    2004-01-01

    Full Text Available Copper(II chloride, in warm ethanolic solution, reacted with 2-amino and 2-methylbenzimidazole derivatives to give complexes of the formula CuL2Cl2·nH2O, where L=1-benzyl-2-aminobenzimidazole 1-(4-methylbenzyl-2-aminobenzimidazole, 1-benzyl-2-methylbenzimidazole and 1-(4-methylbenzyl-2-methylbenzimidazole( n=1 or 2. The complexes were characterized by elemental analysis of the metal, molar conductivity magnetic susceptibility measurements and IR spectra. The molar conductivities of copper(IIcomplexes in dimethyl formamide (DMF corresponding to a 1:1 type of electrolyte indicate that in all the complexes one of the coordinated chloride ions has been replaced by DMF molecule. The room temperature effective magnetic moments and IR data of the complexes suggest that all Cu(II complexes have a tetrahedral configuration, which is realized by participation of the pyridine nitrogen of two organic ligand molecules and two chloride anions. The antimicrobial activity of the ligands and their complexes against Pseudomonas aeruginosa, Bacillus sp. Staphylococcus aureus, Sarcina lutea and Saccharomyces cerevisiae was investigated. The effect of copper complexation on the ligand antimicrobial activity is discussed.

  8. Novel chemical synthesis and characterization of copper pyrovanadate nanoparticles and its influence on the flame retardancy of polymeric nanocomposites

    Science.gov (United States)

    Ghiyasiyan-Arani, Maryam; Masjedi-Arani, Maryam; Ghanbari, Davood; Bagheri, Samira; Salavati-Niasari, Masoud

    2016-05-01

    In this work, copper pyrovanadate (Cu3V2O7(OH)2(H2O)2) nanoparticles have been synthesized by a simple and rapid chemical precipitation method. Different copper-organic complexes were used to control the size and morphology of products. The morphology and structure of the as-synthesized products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectrum, electron dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), differential thermal analysis (DTA) and photoluminescence (PL) spectroscopy. The influence of copper pyrovanadate nanostructures on the flame retardancy of the polystyrene, poly vinyl alcohol and cellulose acetate was studied. Dispersed nanoparticles play the role of a magnetic barrier layer, which slows down product volatilization and prevents the flame and oxygen from the sample during decomposition of the polymer. Cu3V2O7(OH)2(H2O)2 is converted to Cu3V2O8 with an endothermic reaction which simultaneously releases water and decrease the temperature of the flame region.

  9. Study of Pitting Corrosion Behavior of FSW weldments of AA6101- T6 Aluminium Alloy

    Directory of Open Access Journals (Sweden)

    L.V. Kamble

    2015-09-01

    Full Text Available Friction Stir Welding (FSW is a promising solid state joining process widely used generally for Al alloys, especially in aerospace, marine and automobile applications. In present work, the microstructure and corrosion behavior of friction stir welded AA6101 T6 Al alloy is studied. The friction stir welding was carried using vertical milling machine with different tool rotational speeds and welding speeds. The microstructure at weld nugget or stir zone (SN, thermo-mechanically affected zone (TMAZ, heat affected zone (HAZ and base metal were observed using optical microscopy. The corrosion tests of base alloy and welded joints were carried out in 3.5% NaCl solution at temperature of 30º C. Corrosion rate and emf were determined using cyclic polarization measurement.

  10. An analysis of boundary condition effects on the thermomechanical modeling of the FSW process

    Science.gov (United States)

    Guedoiri, A.; Moufki, A.; Favier, V.; Zahrouni, H.

    2011-01-01

    The aim of the present work is to study the influence of thermal boundary conditions on the simulation of friction stir welding process "FSW". Generally, dimensions of the workpieces to be welded are very large and a very small zone surrounding the welding tool is modeled for the thermomechanical study of the process. This area, named box, should be small enough to reduce the computation time and large enough to minimize effects of boundary conditions. It is well known that during welding, the mixing zone is closed arround the tool; it is easily identified by analyzing the velocity field which is complex in contact interface with the tool and which tends rapidly to the tool traverse speed far from the tool. In the thermal analysis, the boundary conditions are not obvious since they depend on the welding parameters, on the workpiece dimensions and on its vicinity. We propose in this study a numerical strategy for determining the thermal boundary conditions on the box.

  11. Weightage Allocation to influential parameters in FSW for Yield Strength Evaluation

    Directory of Open Access Journals (Sweden)

    Krishan Mohan Baghel

    2016-05-01

    Full Text Available Friction Stir Welding is the process used for joining relatively softer material like aluminum and its alloys, using a non-consumable tool. The flow of material governs the yield strength of the joint in FSW and there are various parameters which affect this flow. The analytical study conducted in this paper presents rotational speed, welding speed, axial force and tool pin radius as the most influential of these parameters. This work is an attempt to study their effects on yield strength separately by considering maximum temperature generated in the weld zone as governing constraint and then finding and empirical relationship considering the weightage of each parameter in yield strength calculation. This results in the evaluation of optimal range of these parameters and optimal value of yield strength.

  12. Characterization of a sensitive and selective copper optode based on β-ketoimine modified calix[4]arene derivative

    Energy Technology Data Exchange (ETDEWEB)

    Rouis, A., E-mail: rouisahlem2@yahoo.fr [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des sciences de Monastir, Avenue de l' Environnement, 5000 Monastir (Tunisia); Echabaane, M.; Sakly, N. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des sciences de Monastir, Avenue de l' Environnement, 5000 Monastir (Tunisia); Bonnamour, I. [Institut de Chimie and Biochimie Moléculaires and Supramoléculaires (ICBMS), UMR CNRS 5246, 43 Boulevard du 11 Novembre 1918, Université Claude Bernard Lyon 1, 69100 Villeurbanne (France); Ben Ouada, H. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des sciences de Monastir, Avenue de l' Environnement, 5000 Monastir (Tunisia)

    2015-01-01

    In this paper, an optical sensor was proposed for sensitive determination of copper (II) ions in aqueous solution. The sensing membrane was prepared by coating β-ketoimine calix[4]arene derivative as ionophore on a glass plate surface. Thin β-ketoimine calix[4]arene layer was characterized by contact angle measurements showing a good surface coverage. Besides, a smooth and homogeneous morphology of the calixarene membrane was examined by atomic force microscopy (AFM). The response of the optode is based on the decrease in the absorbance signal at 309 nm upon exposure to buffer solutions containing Cu{sup 2+} ions. At a pH 6.8, the proposed sensor displays a calibration response for copper over a wide concentration range of 1.0 × 10{sup −7} M to 1.0 × 10{sup −4} M with a detection limit of 2.0 × 10{sup −8} M and response time of 7–10 min. This optode exhibits good selectivity toward copper ions in comparison with common ions including Hg{sup 2+} and Ag{sup +} ions. The copper sensing film can be regenerated using 0.01 M HNO{sub 3} solution. In addition to its high stability, repeatability and reproducibility, the sensor shows operational life time of 4 weeks. - Highlights: • Optical sensor for Cu{sup 2+} ion based on β-ketoimine calix[4]arene was developed. • Sensing mechanism involved the formation of a complex between calixarene and Cu{sup 2+}. • Satisfactory analytical sensing characteristics for determining Cu{sup 2+} were obtained.

  13. Synthesis, characterization, electrochemical studies and DFT calculations of amino acids ternary complexes of copper (II) with isonitrosoacetophenone. Biological activities

    Science.gov (United States)

    Tidjani-Rahmouni, Nabila; Bensiradj, Nour el Houda; Djebbar, Safia; Benali-Baitich, Ouassini

    2014-10-01

    Three mixed complexes having formula [Cu(INAP)L(H2O)2] where INAP = deprotonated isonitrosoacetophenone and L = deprotonated amino acid such as histidine, phenylalanine and tryptophan have been synthesized. They have also been characterized using elemental analyses, molar conductance, UV-Vis, IR and ESR spectra. The value of molar conductance indicates them to be non-electrolytes. The spectral studies support the binding of the ligands with two N and two O donor sites to the copper (II) ion, giving an arrangement of N2O2 donor groups. Density Functional Theory (DFT) calculations were applied to evaluate the cis and trans coordination modes of the two water molecules. The trans form was shown to be energetically more stable than the cis one. The ESR data indicate that the covalent character of the metal-ligand bonding in the copper (II) complexes increases on going from histidine to phenylalanine to tryptophan. The electrochemical behavior of the copper (II) complexes was determined by cyclic voltammetry which shows that the chelate structure and electron donating effects of the ligands substituent are among the factors influencing the redox potentials of the complexes. The antimicrobial activities of the complexes were evaluated against several pathogenic microorganisms to assess their antimicrobial potentials. The copper complexes were found to be more active against Gram-positive than Gram-negative bacteria. Furthermore, the antioxidant efficiencies of the metal complexes were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The antioxidant activity of the complexes indicates their moderate scavenging activity against the radical DPPH.

  14. Investigations on tunneling and kissing bond defects in FSW joints for dissimilar aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Noor Zaman, E-mail: noor_0315@yahoo.com [Department of Mechanical Engineering, Jamia Millia Islamia (A Central University), New Delhi (India); Siddiquee, Arshad Noor; Khan, Zahid A. [Department of Mechanical Engineering, Jamia Millia Islamia (A Central University), New Delhi (India); Shihab, Suha K. [Department of Mechanical Engineering, Engineering College, Diyala University, Diyala (Iraq)

    2015-11-05

    In this paper an attempt has been made to investigate the effect of two Friction Stir Welding (FSW) parameters i.e. tool pin offset and tool plunge depth on the formation of defects such as tunnel (tunneling defect) and kissing bond (KB) during welding of dissimilar aluminum alloys. 4.75 mm thick plates of AA5083-H116 and AA6063-T6 were welded using a novel work-fixture developed in-house which, apart from clamping the plated also imparted continuous variation of offset on both side of the faying line. The tunneling defect was modeled as a function of offset and plunge depth. The welds were characterised using optical microscopy (OM), scanning electron microscopy (SEM) and mechanical testing. The causes of such defects have been analyzed and discussed and recommendations have been made to prevent their occurrence. The findings of the study have revealed that the tunneling defects are formed at all offset (including zero offset) values towards stronger material (advancing side). And the cross-section of the tunnel varied with the amount of offset. Further, KBs are formed at the interface for all pin offset values except 0.5 mm towards weaker material and high plunge depth resulting in the poor mechanical properties. - Highlights: • Two dissimilar aluminum alloys are welded using FSW. • Formation of kissing bond and tunneling defects are investigated. • Defects are formed at pin offsets towards stronger material and also without offset. • The size of tunnel reduces significantly by increasing the plunge depth. • Tool pin offset towards weaker material prevent tunneling defects.

  15. Synthesis, Crystal Structure, and Characterization of Ternary Copper(II Complex Derived from N-(salicylidene-L-valine

    Directory of Open Access Journals (Sweden)

    Sundaramurthy Santha Lakshmi

    2016-01-01

    Full Text Available Ternary Schiff base copper(II complex [CuL(tmpda] (where H2L is N-(salicylidene-L-valine; tmpda is N,N,N′,N′-tetramethyl-1,3-propanediamine has been characterized by UV-Vis., FTIR, and single crystal XRD. The crystal structure displays a distorted square pyramidal geometry in which Schiff base is bonded to the Cu(II ion via phenolate oxygen, imine nitrogen, and an oxygen atom of the carboxylate group through the basal plane and the chelating diamine, N,N,N′,N′-tetramethyl-1,3-propanediamine, displays an axial and equatorial mode of binding via NN-donor atoms.

  16. Estimates of N2 narcosis and O2 toxicity during submarine escapes from 600 to 1,000 fsw.

    Science.gov (United States)

    Connor, Christopher W; Ferrigno, Massimo

    2009-01-01

    The U.S. Navy recommends submarine escape for depths down to 600 fsw, with deeper escapes entailing the risks of decompression sickness, nitrogen (N2) narcosis and CNS oxygen (O2) toxicity. However, the escape equipment, including the submarine escape and immersion equipment and the escape trunk, could probably function even at 1,000 fsw. Here we report a theoretical analysis of the risks of both N2 narcosis and CNS O2 toxicity for different escape profiles from 600 to 1,000 fsw. The effect of N2 narcosis, calculated as a function of N2 pressure in the brain using Gas Man software, was expressed as equivalent narcosis depth (END), corresponding to the depth at which the same pressure of N2 would be produced in the brain after five minutes of scuba diving with air. The risk of O2-induced convulsions was estimated using the model developed by Arieli et al. Different dwell times (DTs) at maximal pressure in the escape trunk (from 0 to 60 s) and lungs-to-brain circulation times (10 to 30 s) were included in our analysis. When DT in the escape trunk is very short (e.g., 10 s), the risk of either incapacitating N2 narcosis and/or O2-induced convulsions occurring in the trunk is low, even during escapes from 1,000 fsw.

  17. Nanoscale Surface Characterization of Aqueous Copper Corrosion: Effects of Immersion Interval and Orthophosphate Concentration

    Science.gov (United States)

    Morphology changes for copper surfaces exposed to different water parameters were investigated at the nanoscale with atomic force microscopy (AFM), as influenced by changes in pH and the levels of orthophosphate ions. Synthetic water samples were designed to mimic physiological c...

  18. Physical characterization and recovery of corroded fingerprint impressions from postblast copper pipe bomb fragments.

    Science.gov (United States)

    Bond, John W; Brady, Thomas F

    2013-05-01

    Pipe bombs made from 1 mm thick copper pipe were detonated with a low explosive power powder. Analysis of the physical characteristics of fragments revealed that the copper had undergone work hardening with an increased Vickers Hardness of 107HV1 compared with 80HV1 for unexploded copper pipe. Mean plastic strain prior to fracture was calculated at 0.28 showing evidence of both plastic deformation and wall thinning. An examination of the external surface showed microfractures running parallel with the length of the pipe at approximately 100 μm intervals and 1-2 μm in width. Many larger fragments had folded "inside out" making the original outside surface inaccessible and difficult to fold back through work hardening. A visual examination for fingerprint corrosion revealed ridge details on several fragments that were enhanced by selective digital mapping of colors reflected from the surface of the copper. One of these fingerprints was identified partially to the original donor.

  19. [Characterization of Wood Surface Treated with Electroless Copper Plating by Near Infrared Spectroscopy Technology].

    Science.gov (United States)

    Qin, Jing; Zhang, Mao-mao; Zhao, Guang-jie; Yang, Zhong

    2015-05-01

    Wood electromagnetic shielding material, which was made by treating wood with electroless plating, not only keep the superior characteristics of wood, but also improve the conductivity, thermal conductivity and electromagnetic shielding properties of wood. The emergence of this material opens the way to the value-added exploitation of wood and widens the processing and application field for the electromagnetic shielding material. In order to explore the feasibility of using NIR technology to investigate the properties of wood electromagnetic shielding material, this study analysis the samples before and after copper plated process by the NIR spectroscopy coupled with principal component analysis (PCA). The results showed that (1) there exist significant differences between samples before and after copper plated process both on the spectral shape and absorption, and the great differences can also be seen in the samples with different treat time, especially for the samples with 5 min treat time; (2) after PCA analysis, six clusters from the samples before and after copper plated process were separately distributed in the score plot, and the properties of untreated wood and sensitized wood were similar, and the properties of samples for 25 and 40 min treat time were also similar in order that these samples were close to each other, all of which might suggest that the NIR spectroscopy reflected major feature information about material treatment; (3) After comparing the PCA performance between NIR and visible spectral region, it could be found that the classification performance of samples before and after copper plated process based on the NIR region were better than that based on the visible region, and the information of color on the surface of samples were preferably reflected in the visible region, which could indicate that there are more information about samples' surface characters using the visible spectroscopy coupled with NIR spectroscopy and it is feasible to

  20. Atom probe tomography characterizations of high nickel, low copper surveillance RPV welds irradiated to high fluences

    Science.gov (United States)

    Miller, M. K.; Powers, K. A.; Nanstad, R. K.; Efsing, P.

    2013-06-01

    The Ringhals Units 3 and 4 reactors in Sweden are pressurized water reactors (PWRs) designed and supplied by Westinghouse Electric Company, with commercial operation in 1981 and 1983, respectively. The reactor pressure vessels (RPVs) for both reactors were fabricated with ring forgings of SA 508 class 2 steel. Surveillance blocks for both units were fabricated using the same weld wire heat, welding procedures, and base metals used for the RPVs. The primary interest in these weld metals is because they have very high nickel contents, with 1.58 and 1.66 wt.% for Unit 3 and Unit 4, respectively. The nickel content in Unit 4 is the highest reported nickel content for any Westinghouse PWR. Although both welds contain less than 0.10 wt.% copper, the weld metals have exhibited high irradiation-induced Charpy 41-J transition temperature shifts in surveillance testing. The Charpy impact 41-J shifts and corresponding fluences are 192 °C at 5.0 × 1023 n/m2 (>1 MeV) for Unit 3 and 162 °C at 6.0 × 1023 n/m2 (>1 MeV) for Unit 4. These relatively low-copper, high-nickel, radiation-sensitive welds relate to the issue of so-called late-blooming nickel-manganese-silicon phases. Atom probe tomography measurements have revealed ˜2 nm-diameter irradiation-induced precipitates containing manganese, nickel, and silicon, with phosphorus evident in some of the precipitates. However, only a relatively few number of copper atoms are contained within the precipitates. The larger increase in the transition temperature shift in the higher copper weld metal from the Ringhals R3 Unit is associated with copper-enriched regions within the manganese-nickel-silicon-enriched precipitates rather than changes in their size or number density.

  1. The Synthesis and Characterization of Rouaite, a Copper Hydroxy Nitrate: An Integrated First-Year Laboratory Project

    Science.gov (United States)

    Bushong, Elizabeth J.; Yoder, Claude H.

    2009-01-01

    The synthesis and analysis of a copper hydroxy nitrate provides an exposure to a simple ionic synthesis, qualitative analysis of copper and nitrate, two gravimetric analyses (copper and nitrate), one volumetric analysis (hydroxide), and a colorimetric analysis (copper). The results allow the student to determine the identity of the double salt and…

  2. Characterization of Timed Changes in Hepatic Copper Concentrations, Methionine Metabolism, Gene Expression, and Global DNA Methylation in the Jackson Toxic Milk Mouse Model of Wilson Disease

    Directory of Open Access Journals (Sweden)

    Anh Le

    2014-05-01

    Full Text Available Background: Wilson disease (WD is characterized by hepatic copper accumulation with progressive liver damage to cirrhosis. This study aimed to characterize the toxic milk mouse from The Jackson Laboratory (Bar Harbor, ME, USA (tx-j mouse model of WD according to changes over time in hepatic copper concentrations, methionine metabolism, global DNA methylation, and gene expression from gestational day 17 (fetal to adulthood (28 weeks. Methods: Included liver histology and relevant biochemical analyses including hepatic copper quantification, S-adenosylmethionine (SAM and S-adenosylhomocysteine (SAH liver levels, qPCR for transcript levels of genes relevant to methionine metabolism and liver damage, and DNA dot blot for global DNA methylation. Results: Hepatic copper was lower in tx-j fetuses but higher in weanling (three weeks and adult tx-j mice compared to controls. S-adenosylhomocysteinase transcript levels were significantly lower at all time points, except at three weeks, correlating negatively with copper levels and with consequent changes in the SAM:SAH methylation ratio and global DNA methylation. Conclusion: Compared to controls, methionine metabolism including S-adenosylhomocysteinase gene expression is persistently different in the tx-j mice with consequent alterations in global DNA methylation in more advanced stages of liver disease. The inhibitory effect of copper accumulation on S-adenosylhomocysteinase expression is associated with progressively abnormal methionine metabolism and decreased methylation capacity and DNA global methylation.

  3. One-pot electrodeposition, characterization and photoactivity of stoichiometric copper indium gallium diselenide (CIGS) thin films for solar cells.

    Science.gov (United States)

    Harati, Mohammad; Jia, Jia; Giffard, Kévin; Pellarin, Kyle; Hewson, Carly; Love, David A; Lau, Woon Ming; Ding, Zhifeng

    2010-12-14

    Herein we report the one-pot electrodeposition of copper indium gallium diselenide, CuIn(1-x)Ga(x)Se(2) (CIGS), thin films as the p-type semiconductor in an ionic liquid medium consisting of choline chloride/urea eutectic mixture known as Reline. The thin films were characterized by scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman microspectroscopy, and UV-visible spectroscopy. Based on the results of the characterizations, the electrochemical bath recipe was optimized to obtain stoichiometric CIGS films with x between 0.2 and 0.4. The chemical activity and photoreactivity of the optimized CIGS films were found to be uniform using scanning electrochemical microscopy and scanning photoelectrochemical microscopy. Low-cost stoichiometric CIGS thin films in one-pot were successfully fabricated.

  4. Hardness analysis and morphological characterization of copper-zinc alloys produced in pyrophosphate-based electrolytes

    Directory of Open Access Journals (Sweden)

    Lilian Ferreira de Senna

    2005-09-01

    Full Text Available In this work, copper-zinc alloy coatings on mild steel substrates were obtained in nontoxic pyrophosphate-based electrolytes, at room temperature and under continuous current. The effects of bath composition and current density on the hardness of the coatings, as well as on their morphologies, were evaluated. The results showed that the electrolyte composition, and the use of stress relieving additives strongly influence the hardness of the coatings, while the current density directly affect their morphology. Hence, for a current density of 116 A/m², copper-zinc alloy deposits with no pores or cracks were produced in a pyrophosphate-based electrolyte, especially when allyl alcohol was added to the solution.

  5. Electrochemical synthesis and optical characterization of copper selenide nanowire arrays within the alumina pores

    Science.gov (United States)

    Jagminas, A.; Juškėnas, R.; Gailiūtė, I.; Statkutė, G.; Tomašiūnas, R.

    2006-09-01

    By choosing an appropriate aqueous solution containing CuSO 4, H 2SeO 3, MgSO 4, and H 2SO 4 the suitable composition for two- or one-phase copper selenide deposition within the alumina pores under alternating current (AC) electrolysis conditions was created. X-ray diffraction spectra recorded within 15-55° 2 Θ range revealed fabrication of Cu 3Se 2+Cu 2-xSe or almost pure Cu 2-xSe crystalline material. The compositional and morphological studies using XRD, EDX, SEM, and TEM techniques show fabrication of nearly pure Cu 2-xSe with some deficiency of copper, say, Cu 1.75Se, nanowires in length up to several microns when the selenious acid to copper-ion ratio is close to 1:2 and pH of the bath is <1.25. The fundamental absorption spectrum for this nanostructured material was shown to be formed by allowed direct and indirect interband transitions with the evaluated energy band gaps 2.3 and 1.1 eV, respectively.

  6. Chemical characterization of selected high copper dental amalgams using XPS and XRD techniques

    Energy Technology Data Exchange (ETDEWEB)

    Talik, E. [A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland)]. E-mail: talik@us.edu.pl; Babiarz-Zdyb, R. [A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Dziedzic, A. [Medical University of Silesia, Department of Conservative Dentistry and Periodontology, Akademicki 17 Sqr., 41-209 Bytom (Poland)

    2005-08-02

    The study was carried out to analyze some dependencies between the composition of seven high copper dental amalgams and mercury release behavior, as well as oxygen reactivity of metallic elements. Chemical comparative analysis of selected dental amalgams was carried out using X-ray photoelectron spectroscopy (XPS) technique and X-ray diffraction (XRD) method. The X-ray powder diffraction measurements revealed two main phases for measured amalgams: {gamma}{sub 1}-(Ag{sub 2}Hg{sub 3}) and {eta}'-(Cu{sub 6}Sn{sub 5}). The amount of mercury obtained by the XPS method was lower than the value quoted in the manufacturer's literature, which suggested evaporation of mercury under the UHV conditions. A linear decrease of oxygen and carbon contamination with the growing amount of Cu and Ag was observed. The XPS analysis showed that a high Sn concentration caused less resistance to oxidation. Some of the amalgams contained some extra elements, such as Bi, In, and Zn. All samples contained lead in metallic state and oxides. The amount of Ag, Cu, Sn ingredients determines the main properties of high copper amalgams and plays an important role in mercury evaporation. High tin concentration combined with the presence of smaller amounts of silver and copper (high Sn/Ag ratio) may influence the increase of mercury vaporization.

  7. Characterization of laser ablation of copper in the irradiance regime of laser-induced breakdown spectroscopy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Picard, J., E-mail: jessica.picard@cea.fr [Commissariat à l' Energie Atomique, DAM, Valduc, F-21120 Is-sur-Tille (France); Sirven, J.-B.; Lacour, J.-L. [Commissariat à l' Energie Atomique, DEN/DANS/DPC/SEARS/LANIE, Saclay, F-91191 Gif-sur-Yvette (France); Musset, O. [Université de Bourgogne, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR CNRS 5209, F-21000 Dijon (France); Cardona, D.; Hubinois, J.-C. [Commissariat à l' Energie Atomique, DAM, Valduc, F-21120 Is-sur-Tille (France); Mauchien, P. [Commissariat à l' Energie Atomique, DEN/DANS/DPC/SEARS/LANIE, Saclay, F-91191 Gif-sur-Yvette (France)

    2014-11-01

    The LIBS signal depends both on the ablated mass and on the plasma excitation temperature. These fundamental parameters depend in a complex manner on laser ablation and on laser–plasma coupling. As several works in the literature suggest that laser ablation processes play a predominant role compared to plasma heating phenomena in the LIBS signal variations, this paper focuses on the study of laser ablation. The objective was to determine an interaction regime enabling to maximally control the laser ablation. Nanosecond laser ablation of copper at 266 nm was characterized by scanning electron microscopy and optical profilometry analysis, in air at 1 bar and in the vacuum. The laser beam spatial profile at the sample surface was characterized in order to give realistic values of the irradiance. The effect of the number of accumulated laser shots on the crater volume was studied. Then, the ablation crater morphology, volume, depth and diameter were measured as a function of irradiance between 0.35 and 96 GW/cm². Results show that in the vacuum, a regular trend is observed over the whole irradiance range. In air at 1 bar, below a certain irradiance, laser ablation is very similar to the vacuum case, and the ablation efficiency of copper was estimated at 0.15 ± 0.03 atom/photon. Beyond this irradiance, the laser beam propagation is strongly disrupted by the expansion of the dense plasma, and plasma shielding appears. The fraction of laser energy used for laser ablation and for plasma heating is estimated in the different irradiance regimes. - Highlights: • The morphology of copper's craters was studied as a function of the pulse energy. • Correlation at low energy and two pressures between crater volume and pulse energy • The ablation efficiency of copper at 1 bar is equal to 0.15 atom/photon. • Ablation efficiency in the vacuum is not limited by laser–plasma interaction. • Physical mechanisms of laser ablation at both pressures are discussed.

  8. Characterization and modeling of microstructural evolution of near-eutectic tin-silver-copper solder joints

    Science.gov (United States)

    Zbrzezny, Adam R.

    Near-eutectic Sn-Ag-Cu (SAC) solders are currently considered as major lead-free replacement candidates for Sn-Pb eutectic alloys in microelectronics applications. In this thesis, the microstructural thermal stability including recrystallization, grain growth behavior, Pb and Au contamination effects and interaction of the SAC solder with Cu and Ni substrates were investigated. The true eutectic composition of the Sn-Ag-Cu alloy was verified to be Sn3.5Ag0.9Cu wt.%, and the eutectic melting temperature was determined to be 217.4 +/- 0.8°C. The system was classified as belonging to faceting (Cu6Sn5)-faceting (Ag3Sn)-nonfaceting (Sn matrix) ternary eutectic. The most significant consequence of Pb contamination was the formation of a quaternary eutectic phase (Sn-Ag-Cu-Pb) with a melting point at 176°C. Similarly, the presence of gold in the SAC alloy led to a development of a new quaternary phase (Sn-Ag-Cu-Au) melting at 204°C. Prolonged aging of SAC-4 wt.% Au on nickel resulted in the deposition of a new, previously unreported, intermetallic (IMC) layer, ((Au1-xCUx)6Sn 5, 15 wt.% of Au) on top of the existing (Cu1-yNi y)6Sn5 layer. The interfacial products that formed during soldering to copper were Cu6Sn5 and Cu3Sn. Soldering to nickel resulted in the formation of one layer, (Cu1-yNiy) 6Sn5, which was different from the expected Ni3Sn 4 layer. A small copper content in the SAC solder (0.7 wt.%) was sufficient to promote this thermodynamic shift. Intermetallic growth on Cu during solid state aging was established to be bulk diffusion controlled. The IMC layers in the SAC system grew at a slower rate than in the Sn-Pb system. It was found that the reliability of SAC solder joints on copper was considerably better than on nickel due to copper enrichment during reflow and subsequent Cu6Sn5 intermetallic precipitation. Enhanced copper and silver diffusion followed by tin recrystallization and grain growth, cavity nucleation and subsequent micro-crack linkage formed

  9. Unusual conformation of a dinuclear paddle wheel copper(II) complex. Synthesis, structural characterization and EPR studies.

    Science.gov (United States)

    Paredes-García, Verónica; Santana, Ricardo C; Madrid, Rosa; Vega, Andrés; Spodine, Evgenia; Venegas-Yazigi, Diego

    2013-08-05

    An unusual and unique conformation of a paddle wheel type binuclear copper(II) complex containing acetate and acetamido ligands, {Cu2(μ2-O2CCH3)4}(OCNH2CH3) (1), was obtained by solvothermal synthesis. The structural characterization of this compound shows that the apical (acetamido) ligands are disposed at a 62° dihedral angle, generating a special conformation as a consequence of the synthetic method used. This conformation has not been reported in other paddle wheel copper(II) tetraacetate compounds. Electron paramagnetic resonance (EPR) spectra of powder samples of (1) were obtained at 9.5 and 33.8 GHz, while single crystal spectra were obtained at 33.8 GHz with a B0 applied in three orthogonal planes. The fit of the single crystal experimental data allowed gave g∥ = 2.345 ± 0.003, and g⊥ = 2.057 ± 0.005. The angular variation of the EPR line allows evaluation of the fine structure of (1), giving D = -0.337 ± 0.002 cm(-1) and E = -0.005 ± 0.001 cm(-1). The line width angular dependence, used together with the Anderson model and Kubo-Tomita theory, permitted the interdimer interaction to be evaluated as |J'| = (0.051 ± 0.002) cm(-1). Using the powder spectral temperature dependence it was possible to evaluate the intradinuclear exchange coupling constan J0 as -101 ± 2 cm(-1), which is considerably lower than that reported for other analogous copper(II) tetraacetate paddle wheel compounds (Cu(II)-PW), showing the remarkable effect of the conformation of the terminal ligands on the magnetic interaction.

  10. Synthesis, characterization, plasmid cleavage and cytotoxicity of cancer cells by a copper(II) complex of anthracenyl-terpyridine.

    Science.gov (United States)

    Kumar, Amit; Chinta, Jugun Prakash; Ajay, Amrendra Kumar; Bhat, Manoj Kumar; Rao, Chebrolu P

    2011-11-01

    Metallo-organic compounds are interesting to study for their antitumor activity and related applications. This paper deals with the syntheses, characterization, structure determination of a copper complex of anthracenyl terpyridine (1) and its plasmid cleavage and cytotoxicity towards different cancer cell lines. The complex binds CT-DNA through partial intercalation mode. The plasmid cleavage studies carried out using pBR322 and pUC18 resulted in the formation of all the three forms of the plasmid DNA. Plasmid cleavage studies carried out with a non-redoxable Zn(2+) complex (2) supported the role of the redox activity of copper in 1. The complex 1 showed remarkable antiproliferative activity against cancer cell lines, viz., cervical (HeLa, SiHa, CaSki), breast (MCF-7), liver (HepG2) and lung (H1299). A considerable lowering was observed in the IC(50) values of HPV-infected (viz., HeLa, SiHa, CaSki) vs. non-HPV-infected cell lines (MCF-7, HepG2, H1299). Antiproliferative activity of 1 was found to be much higher than the carboplatin when treated with the same cell lines. Incubation of the cells with 1 results in granular structures only with the HPV-infected cells and not with others as studied by phase contrast and fluorescence microscopy. The lower IC(50) value observed in case of 1 with HPV-infected cell lines may be correlated with the involvement of HPV oncoprotein. The role of HPV has been further augmented by transfecting the MCF-7 cells (originally not possessing HPV copy) with e6 oncoprotein cDNA. To our knowledge this is the first copper complex that causes cell death by interacting with HPV oncoprotein followed by exhibition of remarkable antiproliferative activity.

  11. SIMULACIÓN DE LA TEMPERATURA EN EL PROCESO "FRICTION STIT WELDING" (FSW DE ALUMINIO AA 1100-0 // SIMULATION OF THE TEMPERATURE IN THE PROCESS FRICTION STIR WELDING" (FSW OF AA 1100-0 ALUMINIUM

    Directory of Open Access Journals (Sweden)

    Raisa Valdivé Lunar

    2012-12-01

    Full Text Available The work presented shows the simulated values of the temperatures experimentally un-dertaken in [1] and [11] during friction stir welding (FSW of AA 1100-0 aluminum plates. This is done using the finite element method (FEM. We studied the behavior of temperature by applying MEF to the heat transfer equation used by [9]. The methodology used allowed modeling the problem using the software ABAQUS /CAE v6.7-1 with elements hexahedral of eight nodes and tetrahedral of four nodes. The simulation of the AA 1100-0 aluminum FSW reported a temperature difference of 80.3 C compared to the maximum value obtained experimentally by [1]. The result shows that the process modeling allows to predict the thermal behavior of the weld. // RESUMEN: The work presented shows the simulated values of the temperatures experimentally un-dertaken in [1] and [11] during friction stir welding (FSW of AA 1100-0 aluminum plates. This is done using the finite element method (FEM. We studied the behavior of temperature by applying MEF to the heat transfer equation used by [9]. The methodology used allowed modeling the problem using the software ABAQUS /CAE v6.7-1 with elements hexahedral of eight nodes and tetrahedral of four nodes. The simulation of the AA 1100-0 aluminum FSW reported a temperature difference of 80.3 C compared to the maximum value obtained experimentally by [1]. The result shows that the process modeling allows to predict the thermal behavior of the weld.

  12. Study and characterization of porous copper oxide produced by electrochemical anodization for radiometric heat absorber

    Science.gov (United States)

    Ben Salem, Sonia; Achour, Zahra Ben; Thamri, Kamel; Touayar, Oualid

    2014-10-01

    The aim of this work is to optimize the different parameters for realization of an absorbing cavity to measure the incident absolute laser energy. Electrochemical oxidation is the background process that allowed the copper blackening. A study of the blackened surface quality was undertaken using atomic force microscopy (AFM) analysis and ultraviolet-visible-infrared spectrophotometry using a Shimadzu spectrophotometer. A two-dimensional and three-dimensional visualization by AFM of the formed oxide coating showed that the copper surfaces became porous after electrochemical etching with different roughness. This aspect is becoming more and more important with decreasing current density anodization. In a 2 mol L -1 of NaOH solution, at a temperature of 90°C, and using a 16 mA cm2 constant density current, the copper oxide formed has a reflectivity of around 3% in the spectral range between 300 and 1,800 nm. Using the `mirage effect' technique, the obtained Cu2O diffusivity and thermal conductivity are respectively equal to (11.5 ± 0.5) 10 to 7 m2 s-1 and (370 ± 20) Wm-1 K-1. This allows us to consider that our Cu2O coating is a good thermal conductor. The results of the optical and thermal studies dictate the choice of the cavity design. The absorbing cavity is a hollow cylinder machined to its base at an angle of 30°. If the included angle of the plane is 30° and the interior surface gives specular reflection, an incoming ray parallel to the axis will undergo five reflections before exit. So the absorption of the surface becomes closely near 0.999999.

  13. Characterization of a Marine Microbial Community Used for Enhanced Sulfate Reduction and Copper Precipitation in a Two-Step Process.

    Science.gov (United States)

    García-Depraect, Octavio; Guerrero-Barajas, Claudia; Jan-Roblero, Janet; Ordaz, Alberto

    2017-06-01

    Marine microorganisms that are obtained from hydrothermal vent sediments present a great metabolic potential for applications in environmental biotechnology. However, the work done regarding their applications in engineered systems is still scarce. Hence, in this work, the sulfate reduction process carried out by a marine microbial community in an upflow anaerobic sludge blanket (UASB) reactor was investigated for 190 days under sequential batch mode. The effects of 1000 to 5500 mg L(-1) of SO4(-2) and the chemical oxygen demand (COD)/SO4(-2) ratio were studied along with a kinetic characterization with lactate as the electron donor. Also, the feasibility of using the sulfide produced in the UASB for copper precipitation in a second column was studied under continuous mode. The system presented here is an alternative to sulfidogenesis, particularly when it is necessary to avoid toxicity to sulfide and competition with methanogens. The bioreactor performed better with relatively low concentrations of sulfate (up to 1100 mg L(-1)) and COD/SO4(-2) ratios between 1.4 and 3.6. Under the continuous regime, the biogenic sulfide was sufficient to precipitate copper at a removal rate of 234 mg L(-1) day(-1). Finally, the identification of the microorganisms in the sludge was carried out; some genera of microorganisms identified were Desulfitobacterium and Clostridium.

  14. Raman, IR, UV-vis and EPR characterization of two copper dioxolene complexes derived from L-dopa and dopamine.

    Science.gov (United States)

    Barreto, Wagner J; Barreto, Sônia R G; Ando, Rômulo A; Santos, Paulo S; DiMauro, Eduardo; Jorge, Thiago

    2008-12-15

    The anionic complexes [Cu(L(1-))3](1-), L(-)=dopasemiquinone or L-dopasemiquinone, were prepared and characterized. The complexes are stable in aqueous solution showing intense absorption bands at ca. 605 nm for Cu(II)-L-dopasemiquinone and at ca. 595 nm for Cu(II)-dopasemiquinone in the UV-vis spectra, that can be assigned to intraligand transitions. Noradrenaline and adrenaline, under the same reaction conditions, did not yield Cu-complexes, despite the bands in the UV region showing that noradrenaline and adrenaline were oxidized during the process. The complexes display a resonance Raman effect, and the most enhanced bands involve ring modes and particularly the nuCC+nuCO stretching mode at ca. 1384 cm(-1). The free radical nature of the ligands and the oxidation state of the Cu(II) were confirmed by the EPR spectra that display absorptions assigned to organic radicals with g=2.0005 and g=2.0923, and for Cu(II) with g=2.008 and g=2.0897 for L-dopasemiquinone and dopasemiquinone, respectively. The possibility that dopamine and L-dopa can form stable and aqueous-soluble copper complexes at neutral pH, whereas noradrenaline and adrenaline cannot, may be important in understanding how Cu(II)-dopamine crosses the cellular membrane as proposed in the literature to explain the role of copper in Wilson disease.

  15. Properties and characterization of agar/CuNP bionanocomposite films prepared with different copper salts and reducing agents.

    Science.gov (United States)

    Shankar, Shiv; Teng, Xinnan; Rhim, Jong-Whan

    2014-12-19

    Various types of agar-based bio-nanocomposite (BNC) films were prepared by blending agar and six different copper nanoparticles (CuNPs) with different shapes and sizes obtained from three different sources of copper salts and two different reducing agents. The BNC films were characterized by UV-visible, FE-SEM, FT-IR, and XRD. The thermogravimetric study showed that the melting point of BNC films was increased when ascorbic acid was used as a reducing agent for CuNPs synthesis. Apparent surface color and transmittance of agar film was greatly influenced by the reinforcement of CuNPs. However, mechanical and water vapor barrier properties did not change significantly (p>0.05) by blending with CuNPs. Tensile modulus and tensile strength decreased slightly for all types of CuNPs reinforced while elongation at break slightly increased when CuNPs produced by ascorbic acid were blended. The agar bio-nanocomposite films showed profound antibacterial activity against both Gram-positive and Gram-negative food-borne pathogenic bacteria.

  16. Copper(II) complexes with 4-hydroxyacetophenone-derived acylhydrazones: Synthesis, characterization, DNA binding and cleavage properties

    Science.gov (United States)

    Gup, Ramazan; Gökçe, Cansu; Aktürk, Selçuk

    2015-01-01

    Two new Cu(II) complexes of Schiff base-hydrazone ligands, hydroxy-N‧-[(1Z)-1-(4-hydroxyphenyl)ethylidene]benzohydrazide [H3L1] and ethyl 2-(4-(1-(2-(4-(2-ethoxy-2-oxoethoxy)benzoyl)hydrazono)ethyl)phenoxy)acetate (HL2) have been synthesized and then characterized by microcopy and spectral studies. X-ray powder diffraction illustrates that [Cu(L2)2] complex is crystalline in nature whereas [Cu(H2L1)2]·2H2O has an amorphous structure. Binding of the copper complexes with Calf thymus DNA (CT-DNA) has been investigated by UV-visible spectra, exhibiting non-covalent binding to CT-DNA. DNA cleavage experiments have been also investigated by agarose gel electrophoresis in the presence and absence of an oxidative agent (H2O2). The effect of complex concentration on the DNA cleavage reaction has been also studied. Both copper complexes show nuclease activity, which significantly depends on concentrations of the complexes, in the presence of H2O2 through oxidative mechanism whereas they slightly cleavage DNA in the absence an oxidative agent.

  17. Synthesis and Characterization of an Unexpected Asymmetric Binuclear Copper(Ⅰ) Complex Containing 4-Vinyl-pyridine

    Institute of Scientific and Technical Information of China (English)

    JIANG, Kai(蒋凯); ZHAO, Dong(赵东); GUO, Li-Bing(郭利兵); ZHANG, Chuan-Jian(张传建); YANG, Rui-Na(杨瑞娜)

    2004-01-01

    The asymmetric binuclear copper(Ⅰ) complex [Cu2(dppm)2(C7H7N)(μ-HCOO)](NO3) (dppm=Ph2PCH2PPh2, C7H7N=4-vinyl-pyridine) has been prepared and characterized by physicochemical and spectroscopic methods. The complex is photoluminescent at room temperature. It crystallizes in triclinic system, space group P-1 with a= 1.2719(3) nm, b= 1.8637(4) nm, c= 1.1656(2) nm, α=97.16(3)°, β= 104.94(3)°, γ=89.39(3)°, V=2.648.1(9) nm3, Dc= 1.390 gbcm-3, Z=2, μ=0.974 mm-1, R=0.0483 for 5716 independently observed reflections with I>2σ(I).The structure consists of [Cu2(dppm)2(C7H7N)(μ-HCOO)]+cations and nitrate anions. The copper atoms show different coordination modes: Cu(1) displays a distorted trigonal and Cu(2) a tetrahedred geometry.

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

    OpenAIRE

    Huang Peng; Kong Yifei; Li Zhiming; Gao Feng; Cui Daxiang

    2010-01-01

    Abstract Herein we firstly reported a simple, environment-friendly, controllable synthetic method of CuSe nanosnakes at room temperature using copper salts and sodium selenosulfate as the reactants, and bovine serum albumin (BSA) as foaming agent. As the amounts of selenide ions (Se2−) released from Na2SeSO3 in the solution increased, the cubic and snake-like CuSe nanostructures were formed gradually, the cubic nanostructures were captured by the CuSe nanosnakes, the CuSe nanosnakes gre...

  19. Electrochemical and optical characterization of cobalt, copper and zinc phthalocyanine complexes.

    Science.gov (United States)

    Lee, Jaehyun; Kim, Se Hun; Lee, Woosung; Lee, Jiwon; An, Byeong-Kwan; Oh, Se Young; Kim, Jae Pil; Park, Jongwook

    2013-06-01

    New phthalocyanine (Pc) derivatives that include the alkyl group in ligand were synthesized based on three core metals such as zinc (Zn), copper (Cu), and cobalt (Co). Electrochemical behaviors and optical properties of the new phthalocyanine derivatives with ligand and different core metal were investigated by using cyclic voltammetry, UV-Visible (UV-Vis) spectroscopy and photoluminescence (PL) spectroscopy. In UV-Vis data, maximum values of 2H, Co, Cu, and Zn complexes were 708 nm and 677 nm, 686 nm, 684 nm, respectively.

  20. Synthesis, structural characterization and thermal properties of copper and silver silyl complexes.

    Science.gov (United States)

    Sgro, Michael J; Piers, Warren E; Romero, Patricio E

    2015-02-28

    The synthesis of copper and silver silyl complexes containing either N-heterocyclic carbenes or nitrogen donors is described. Alterations made to both the neutral donor ligands as well as the silyl group provided access to a number of different compounds. Many of the complexes synthesized were studied in the solid state and the effect of the donor ligand on the final structure of the complexes was examined. The thermal properties of the complexes were explored using thermogravimetric analysis, differential scanning calorimetry and sublimations. Some of the complexes synthesized were demonstrated to be promising volatile metal precursors.

  1. Influence of the configuration of pin on the quality of plastics FSW joints

    Institute of Scientific and Technical Information of China (English)

    Hu Limu

    2006-01-01

    An investigation on the quality of PVC joints welded by friction stir welding ( FSW with different shape of pin was carried out. The results show that when the rotating speed of stir toolis 1 660 r/min and the welding speed is 25 mm/min, the beads welded with upright taper pin are plump and joined well, the average tensile strength of which is 19. 1 MPa ( the maximum is 20. 3 MPa), being 49. 2% of that of parent material. The beads welded with cylindrical pin are also joined rather well plump and smooth, the average tensile strength of which is 17. 6 MPa, being 45.3% of that of parent material.The beads welded with inverted taper and cylindrical screw pin are only partially joined or disjoined. The optimum welding temperature range of PVC is 180 - 190 ℃. If the temperature beyond 200 ℃ the material will be burnt. If the temperature is under 170 ℃ the material will be joined partially or disjoined.

  2. Microhardness and Strain Field Characterization of Self-Reacting Friction Stir and Plug Welds of Dissimilar Aluminum Alloys

    Science.gov (United States)

    Horton, Karla Renee

    2011-01-01

    Friction stir welding (FSW) is a solid state welding process with potential advantages for aerospace and automotive industries dealing with light alloys. Self-reacting friction stir welding (SR-FSW) is one variation of the FSW process being developed at the National Aeronautics and Space Administration (NASA) for use in the fabrication of propellant tanks. Friction plug welding is used to seal the exit hole that remains in a circumferential SR-FSW. This work reports on material properties and strain patterns developed in a SR-FSW with a friction plug weld. Specifically, this study examines the behavior of a SR-FSW formed between an AA 2014-T6 plate on the advancing side and an AA 2219-T87 plate on the retreating side and a SR-FSW (AA 2014-T6 to AA 2219-T87) with a 2219-T87 plug weld. This study presents the results of a characterization of the micro-hardness, joint strength, and strain field characterization of SR-FSW and FPW joints tested at room temperature and cryogenic temperatures.

  3. Numerical simulation of friction stir welding (FSW): Prediction of the heat affect zone using a softening model

    Science.gov (United States)

    Paulo, R. M. F.; Carlone, P.; Valente, R. A. F.; Teixeira-Dias, F.; Palazzo, G. S.

    2016-10-01

    In this work a numerical model is proposed to simulate Friction Stir Welding (FSW) process in AA2024-T3 plates. This model included a softening model that account for the temperature history and the hardness distribution on a welded plate can thus be predicted. The validation of the model was performed using experimental measurements of the hardness in the plate cross-section. There is an acceptable prediction of the material softening in the Heat Affected Zone (HAZ) using the adopted model.

  4. Growth and characterization of single phase Cu2O by thermal oxidation of thin copper films

    Science.gov (United States)

    Choudhary, Sumita; Sarma, J. V. N.; Gangopadhyay, Subhashis

    2016-04-01

    We report a simple and efficient technique to form high quality single phase cuprous oxide films on glass substrate using thermal evaporation of thin copper films followed by controlled thermal oxidation in air ambient. Crystallographic analysis and oxide phase determination, as well as grain size distribution have been studied using X-ray diffraction (XRD) method, while scanning electron microscopy (SEM) has been utilized to investigate the surface morphology of the as grown oxide films. The formation of various copper oxide phases is found to be highly sensitive to the oxidation temperature and a crystalline, single phase cuprous oxide film can be achieved for oxidation temperatures between 250°C to 320°C. Cu2O film surface appeared in a faceted morphology in SEM imaging and a direct band gap of about 2.1 eV has been observed in UV-visible spectroscopy. X-ray photoelectron spectroscopy (XPS) confirmed a single oxide phase formation. Finally, a growth mechanism of the oxide film has also been discussed.

  5. Synthesis, Characterization and Cold Workability of Cast Copper-Magnesium-Tin Alloys

    Science.gov (United States)

    Bravo Bénard, Agustín Eduardo; Martínez Hernández, David; González Reyes, José Gonzalo; Ortiz Prado, Armando; Schouwenaars Franssens, Rafael

    2014-02-01

    The use of Mg as an alloying element in copper alloys has largely been overlooked in scientific literature and technological applications. Its supposed tribological compatibility with iron makes it an interesting option to replace Pb in tribological alloys. This work describes the casting process of high-quality thin slabs of Cu-Mg-Sn alloys with different compositions by means of conventional methods. The resulting phases were analyzed using X-ray diffraction, scanning electron microscopy, optical microscopy, and energy dispersive X-ray spectroscopy techniques. Typical dendritic α-Cu, eutectic Cu2Mg(Sn) and eutectoid non-equilibrium microstructures were found. Tensile tests and Vickers microhardness show the excellent hardening capability of Mg as compared to other copper alloys in the as-cast condition. For some of the slabs and compositions, cold rolling reductions of over 95 pct have been easily achieved. Other compositions and slabs have failed during the deformation process. Failure analysis after cold rolling reveals that one cause for brittleness is the presence of casting defects such as microshrinkage and inclusions, which can be eliminated. However, for high Mg contents, a high volume fraction of the intermetallic phase provides a contiguous path for crack propagation through the connected interdendritic regions.

  6. Analysis of Yttrium-Barium-Copper-Oxide by x ray diffraction and mechanical characterization

    Science.gov (United States)

    Arsenovic, Petar

    1992-01-01

    The efforts in developing high-temperature superconductor (HTSC) YBa2Cu3O7 electrical leads are to benefit future NASA missions that will carry payloads with sensitive instruments operating at cryogenic temperatures. Present-day leads made of copper or magnesium are responsible for as much as 50 percent of the parasitic heat load on cryogenic systems. A reduction of this load could be achieved by replacing the conventional materials with HTSC ceramic electrical leads. Superconductor quality has become a concern in the industry, as has the development of effective evaluation methods. The factors that need to be examined for these materials include material purity, mechanical properties, and superconducting ability below the critical temperature. We applied several methods to study these factors: thermogravimetric analysis, x-ray diffraction, tensile testing, and laser-generated ultrasound. Our objectives were to determine the average tensile strength and Young's modulus of the HTSC material and to compare them to those values for copper and manganin.

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

    Science.gov (United States)

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

    2014-09-01

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

  8. Electrochemical characterization of copper chemical mechanical planarization in KIO{sub 3} slurry

    Energy Technology Data Exchange (ETDEWEB)

    Du Tianbao; Tamboli, Dnyanesh; Luo Ying; Desai, Vimal

    2004-05-15

    Chemical mechanical polishing (CMP) of copper was performed using KIO{sub 3} as oxidizer and alumina particles as abrasives. For planarization of the surface morphology, the control of the surface passivation of Cu is critical during polishing. The copper removal rate decreased dramatically with increasing slurry pH without and with 0.1 M KIO{sub 3}. However, the removal rate is lower at pH 2 in slurry with 0.1 M KIO{sub 3}. The interaction between the Cu and the slurry was investigated by potentiodynamic and electrochemical impedance spectroscopy measurements under static condition. The electrochemical measurements revealed higher corrosion susceptibility at pH 2. XPS analysis indicates the severe precipitation of CuI on Cu at pH 2 in solution with 0.1 M KIO{sub 3}. The lower removal rate at pH 2 could be due to the reduced friction force of the pad with the precipitation of CuI on it. Atomic force microscopic (AFM) measurements were performed on both the etched surface and polished surface. It was shown that the surface roughness of the polished surfaces is better at pH 4 than that of pH 2.

  9. Optical and Morphological Characterization of Sonochemically Assisted Europium Doped Copper (I) Oxide Nanostructures

    Science.gov (United States)

    Cosico, J. A. M.; Ruales, P. K.; Marquez, M. C.

    2017-06-01

    In the age where application of nanotechnology in our society has proven to be eminent, different routes of synthesizing nanoparticles have emerged. In this study nanoparticles of cuprous oxide (Cu2O) doped with different amounts of europium was prepared by using solution precursor route approach with the aid of ultrasonic sound. Copper sulphate and europium (III) nitrate pentahydrate was used as source for copper ions and europium ions respectively. X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR) were used to elucidate the cubic crystal structure and organic impurities present on Cu2Onanoparticles. UV-Vis spectroscopy was used to determine the absorption spectrum of the nanoparticles in the wavelength range of 400nm to 700nm. The bandgap of the undoped and doped Cu2O were found to fall between 2.1eV - 2.3eV. Scanning Electron Microscopy (SEM) coupled with energy dispersive x-ray was used to observe the dendritic and rodlike morphology and the presence of europium in the synthesized Cu2O nanoparticles. The observed effect on the absorbance of Cu2O upon adding Eu and a facile way of synthesizing Cu2O nanoparticles could bring a positive impact on the production of functional devices for optoelectronic and energy applications.

  10. Structural and optical characterization of mechanochemically synthesized copper doped CdS nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, P., E-mail: pireyes@cinvestav.mx [Departamento de Ingenieria Electrica-SEES, CINVESTAV-IPN, Zacatenco, D.F., C.P.07360, Mexico (Mexico); Velumani, S. [Departamento de Ingenieria Electrica-SEES, CINVESTAV-IPN, Zacatenco, D.F., C.P.07360, Mexico (Mexico)

    2012-09-20

    Incorporation of copper into CdS crystals has been successfully prepared by mechanical alloying using a planetary ball mill. The powders are prepared with different milling times at 300 rpm with various Cu/Cd ratios from 0.1 to 25 at%. X-ray diffraction (XRD) analysis of milled powders showed peaks corresponding to hexagonal structure with a detection of phase transition to a cubic structure with increasing milling time. Grain sizes varied from 21 to 30 nm corresponding to different Cu/Cd ratios. Field emission scanning electron microscopy (FESEM) images reveal agglomerated materials with particle size of approximately 28 nm (5 Cu at%) and layered structures caused due to the milling process. Powder composition by energy dispersive analysis of X-rays (EDAX) reveals the incorporation of copper into the CdS. Micro Raman spectroscopy showed peaks approximately at 301 and 585 cm{sup -1} corresponding to first and second order scatterings of longitudinal optical phonon mode. The LO mode at 301 cm{sup -1} shifted towards lower wave number due to decrease of grain size by increase in milling time. From high resolution transmission electron microscope (HRTEM), the dominant phase of individual CdS nanocrystals was found to be hexagonal structure along with cubic structure.

  11. Synthesis And Characterization of Copper Zinc Tin Sulfide Nanoparticles And Thin Films

    Science.gov (United States)

    Khare, Ankur

    Copper zinc tin sulfide (Cu2ZnSnS4, or CZTS) is emerging as an alternative material to the present thin film solar cell technologies such as Cu(In,Ga)Se2 and CdTe. All the elements in CZTS are abundant, environmentally benign, and inexpensive. In addition, CZTS has a band gap of ˜1.5 eV, the ideal value for converting the maximum amount of energy from the solar spectrum into electricity. CZTS has a high absorption coefficient (>104 cm-1 in the visible region of the electromagnetic spectrum) and only a few micron thick layer of CZTS can absorb all the photons with energies above its band gap. CZT(S,Se) solar cells have already reached power conversion efficiencies >10%. One of the ways to improve upon the CZTS power conversion efficiency is by using CZTS quantum dots as the photoactive material, which can potentially achieve efficiencies greater than the present thin film technologies at a fraction of the cost. However, two requirements for quantum-dot solar cells have yet to be demonstrated. First, no report has shown quantum confinement in CZTS nanocrystals. Second, the syntheses to date have not provided a range of nanocrystal sizes, which is necessary not only for fundamental studies but also for multijunction photovoltaic architectures. We resolved these two issues by demonstrating a simple synthesis of CZTS, Cu2SnS3, and alloyed (Cu2SnS3) x(ZnS)y nanocrystals with diameters ranging from 2 to 7 nm from diethyldithiocarbamate complexes. As-synthesized nanocrystals were characterized using high resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and energy dispersive spectroscopy to confirm their phase purity. Nanocrystals of diameter less than 5 nm were found to exhibit a shift in their optical absorption spectra towards higher energy consistent with quantum confinement and previous theoretical predictions. Thin films from CZTS nanocrystals deposited on Mo-coated quartz substrates using drop casting were found to be continuous

  12. Effect of treatment time on characterization and properties of nanocrystalline surface layer in copper induced by surface mechanical attrition treatment

    Indian Academy of Sciences (India)

    Farzad Kargar; M Laleh; T Shahrabi; A Sabour Rouhaghdam

    2014-08-01

    Nanocrystalline surface layers were synthesized on pure copper by means of surface mechanical attrition treatment (SMAT) at various treatment times. The microstructural features of the surface layers produced by SMAT were systematically characterized by optical microscopy (OM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. Hardness and surface roughness measurements were also carried out. It is found that the thickness of the deformed layer increased from 50 to 500 m with increasing treatment time from 10 to 300 min, while the average grain size of the top surface layer decreased from 20 to 7 nm. Hardness of the all SMATed samples decreased with depth. Furthermore, the hardness of the top surface layer of the SMATed samples was at least two times higher than that of the un-treated counterpart. Surface roughness results showed different trend with treatment time. Amounts of PV and a values first sharply increased and then decreased.

  13. Synthesis, characterization and femtosecond nonlinear saturable absorption behavior of copper phthalocyanine nanocrystals doped-PMMA polymer thin films

    Science.gov (United States)

    Zongo, S.; Dhlamini, M. S.; Neethling, P. H.; Yao, A.; Maaza, M.; Sahraoui, B.

    2015-12-01

    In this work, we report the femtosecond nonlinear saturable absorption response of synthesized copper phthalocyanine nanocrystals (CPc-NCs)-doped PMMA polymer thin films. The samples were initially characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV-Vis and scanning electron microscopy (SEM) techniques. The crystalline phase and morphological analysis revealed nanocrystals of monoclinic structure with an average crystallite size between 31.38 nm and 42.5 nm. The femtosecond Z-scan study at 800 nm central wavelength indicated a saturable absorption behavior of which the mechanism is closely related to the surface plasmon resonance (SPR) of the particles. This nonlinear effect could potentially make the CPc-NCs useful in nonlinear optical devices.

  14. Structural characterization and biological evaluation of a clioquinol-ruthenium complex with copper-independent antileukaemic activity.

    Science.gov (United States)

    Gobec, Martina; Kljun, Jakob; Sosič, Izidor; Mlinarič-Raščan, Irena; Uršič, Matija; Gobec, Stanislav; Turel, Iztok

    2014-06-28

    In this study, we present the synthesis, biological characterization, and first crystal structure of an organometallic-clioquinol complex. Combining ruthenium with the established apoptotic agent and 8-hydroxyquinoline derivative, clioquinol, resulted in a complex that induces caspase-dependent cell death in leukaemia cells. This activity is copper independent and is improved compared to the parent compound, clioquinol. The study of the mode of action reveals that this clioquinol-ruthenium complex does not intercalate between DNA base pairs. Additionally, this clioquinol-ruthenium complex shows proteasome-independent inhibition of the NFκB signalling pathway, with no effects on cell-cycle distribution. These data suggest a mechanism of action that involves a target profile that is different from that for clioquinol alone.

  15. Structural characterization of a high affinity mononuclear site in the copper(II)-α-synuclein complex.

    Science.gov (United States)

    Bortolus, Marco; Bisaglia, Marco; Zoleo, Alfonso; Fittipaldi, Maria; Benfatto, Maurizio; Bubacco, Luigi; Maniero, Anna Lisa

    2010-12-29

    Human α-Synuclein (aS), a 140 amino acid protein, is the main constituent of Lewy bodies, the cytoplasmatic deposits found in the brains of Parkinson's disease patients, where it is present in an aggregated, fibrillar form. Recent studies have shown that aS is a metal binding protein. Moreover, heavy metal ions, in particular divalent copper, accelerate the aggregation process of the protein. In this work, we investigated the high affinity binding mode of truncated aS (1-99) (aS99) with Cu(II), in a stoichiometric ratio, to elucidate the residues involved in the binding site and the role of copper ions in the protein oligomerization. We used Electron Paramagnetic Resonance spectroscopy on the Cu(II)-aS99 complex at pH 6.5, performing both multifrequency continuous wave experiments and pulsed experiments at X-band. The comparison of 9.5 and 95 GHz data showed that at this pH only one binding mode is present. To identify the nature of the ligands, we performed Electron Spin Echo Envelope Modulation, Hyperfine Sublevel Correlation Spectroscopy, and pulsed Davies Electron-Nuclear Double Resonance (Davies-ENDOR) experiments. We determined that the EPR parameters are typical of a type-II copper complex, in a slightly distorted square planar geometry. Combining the results from the different pulsed techniques, we obtained that the equatorial coordination is {N(Im), N(-), H(2)O, O}, where N(im) is the imino nitrogen of His50, N(-) a deprotonated amido backbone nitrogen that we attribute to His50, H(2)O an exchangeable water molecule, and O an unidentified oxygen ligand. Moreover, we propose that the free amino terminus (Met1) participates in the complex as an axial ligand. The MXAN analysis of the XAS k-edge absorption data allowed us to independently validate the structural features proposed on the basis of the magnetic parameters of the Cu(II)-aS99 complex and then to further refine the quality of the proposed structural model.

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

    Science.gov (United States)

    Huang, Peng; Kong, Yifei; Li, Zhiming; Gao, Feng; Cui, Daxiang

    2010-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Huang Peng

    2010-01-01

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

  18. Synthesis and characterization of copper antimony tin sulphide thin films for solar cell applications

    Science.gov (United States)

    Ali, N.; Hussain, A.; Ahmed, R.; Wan Shamsuri, W. N.; Fu, Y. Q.

    2016-12-01

    Low price thin film modules based on Copper antimony tin sulphide (CATS) are introduced for solar harvesting to compete for the already developed compound semiconductors. Here, CATS thin films were deposited on soda lime glass by thermal evaporation technique followed by a rapid thermal annealing in an argon atmosphere. From Our XRD analysis, it was revealed that the annealed samples were poly-crystalline and their crystallinity was improved with increasing annealing temperature. The constituent elements and their corresponding chemical states were identified using X-ray photoelectron spectroscopy. The obtained optical band gap of 1.4 eV for CATS thin film is found nearly equal to GaAs - one of the highly efficient thin film material for solar cell technology. Furthermore, our observed good optical absorbance and low transmittance for the annealed CATS thin films in the visible region of light spectrum assured the aptness of the CATS thin films for solar cell applications.

  19. Copper vanadate nanowires-based MIS capacitors: Synthesis, characterization, and their electrical charge storage applications

    KAUST Repository

    Shahid, Muhammad

    2013-07-14

    Copper vanadate (CVO) nanowires were grown on Si/SiO2 substrates by thermal annealing technique. A thin film of a CVO precursor at 550 C under an ambient atmosphere could also be prepared. The electrical properties of the nanowires embedded in the dielectrical layer were examined by capacitance-voltage (C-V) measurements. The C-V curves for Au/CVO nanowires embedded in an hafnium oxide layer/SiO2/p-Si capacitor at 298 K showed a clockwise hysteresis loop when the gate bias was swept cyclically. The hysteresis characteristics were studied further at different frequencies, which clearly indicated that the traps in the nanowires have a large charging-discharging time and thus the as-synthesized nanowires can be utilized for electrical charge storage devices. © 2013 Springer Science+Business Media Dordrecht.

  20. Piper betle-mediated synthesis, characterization, antibacterial and rat splenocyte cytotoxic effects of copper oxide nanoparticles.

    Science.gov (United States)

    Praburaman, Loganathan; Jang, Jum-Suk; Muthusamy, Govarthanan; Arumugam, Sengottaiyan; Manoharan, Koildhasan; Cho, Kwang-Min; Min, Cho; Kamala-Kannan, Seralathan; Byung-Taek, Oh

    2016-09-01

    The study reports a simple, inexpensive, and eco-friendly synthesis of copper oxide nanoparticles (CuONPs) using Piper betle leaf extract. Formation of CuONPs was confirmed by UV-visible spectroscopy at 280 nm. Transmission electron microscopy (TEM) images showed that the CuONPs were spherical, with an average size of 50-100 nm. The scanning electron microscopy (SEM)-energy dispersive spectroscopy (EDS) peak was observed approximately at 1 and 8 keV. The X-ray diffraction (XRD) studies indicated that the particles were crystalline in nature. CuONPs effectively inhibited the growth of phytopathogens Ralstonia solanacearum and Xanthomonas axonopodis. The cytotoxic effect of the synthesized CuONPs was analyzed using rat splenocytes. The cell viability was decreased to 94% at 300 μg/mL.

  1. Fabrication and characterization of copper oxide (CuO)–gold (Au)–titania (TiO{sub 2}) and copper oxide (CuO)–gold (Au)–indium tin oxide (ITO) nanowire heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, Nitin, E-mail: nchopra@eng.ua.edu [Metallurgical and Materials Engineering, Center for Materials for Information Technology (MINT), Box 870202, The University of Alabama, Tuscaloosa, AL 35487 (United States); Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487 (United States); Shi, Wenwu [Metallurgical and Materials Engineering, Center for Materials for Information Technology (MINT), Box 870202, The University of Alabama, Tuscaloosa, AL 35487 (United States); Lattner, Andrew [NSF-REH, Northridge High School, Tuscaloosa, AL 35487 (United States)

    2014-10-15

    Nanoscale heterostructures composed of standing copper oxide nanowires decorated with Au nanoparticles and shells of titania and indium tin oxide were fabricated. The fabrication process involved surfactant-free and wet-chemical nucleation of gold nanoparticles on copper oxide nanowires followed by a line-of-sight sputtering of titania or indium tin oxide. The heterostructures were characterized using high resolution electron microscopy, diffraction, and energy dispersive spectroscopy. The interfaces, morphologies, crystallinity, phases, and chemical compositions were analyzed. The process of direct nucleation of gold nanoparticles on copper oxide nanoparticles resulted in low energy interface with aligned lattice for both the components. Coatings of polycrystalline titania or amorphous indium tin oxide were deposited on standing copper oxide nanowire–gold nanoparticle heterostructures. Self-shadowing effect due to standing nanowire heterostructures was observed for line-of-sight sputter deposition of titania or indium tin oxide coatings. Finally, the heterostructures were studied using Raman spectroscopy and ultraviolet–visible spectroscopy, including band gap energy analysis. Tailing in the band gap energy at longer wavelengths (or lower energies) was observed for the nanowire heterostructures. - Highlights: • Heterostructures comprised of CuO nanowires coated with Au nanoparticles. • Au nanoparticles exhibited nearly flat and low energy interface with nanowire. • Heterostructures were further sputter-coated with oxide shell of TiO{sub 2} or ITO. • The process resulted in coating of polycrystalline TiO{sub 2} and amorphous ITO shell.

  2. Synthesis, Structure and Characterization of Two-dimensional Network Copper Complex [ Cu3 (nta) 2(azpy) 2(H2O)2]· 6H2O

    Institute of Scientific and Technical Information of China (English)

    LI,Bao-Long(李宝龙); XU,Yan(徐艳); LIU,Qi(刘琦); WANG,Hua-Qin(王化勤); XU,Zheng(徐正)

    2002-01-01

    The copper(Ⅱ) complex [Cu3(nta)2(azpy)2(H2O)2] @6H2O(nta= nitrilotriacetate, azpy= 4,4'-azobispyridine) has been synthesized and characterized. The X-ray analysis reveals that there are two kinds of copper(Ⅱ) coordination environments.Cu(1) has a distorted square plane symmetry and Cu(2) has a distorted octahedral symmetry. Cu(1)is linked to Cu(2)through nta and bound to Cu(1C) by azpy, and Cu(2) islinked to Cu(2A) through azpy, which extends to two-dimensional network with large rhombus 1.2 nm× 1.7 nm.

  3. Mechanical and toughness properties of robotic-FSW repair welds in 6061-T6 aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Brinckmann, S.; Strombeck, A. v.; Schilling, C.; Santos, J.F. dos; Kocak, M. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Materialforschung; Lohwasser, D. [DaimlerChrysler Aerospace Airbus GmbH, Bremen (Germany)

    2000-07-01

    Panel or structures welded in fixed installations might require local repair of eventual process induced defects. Ideally such repair operations should take place outside the production line to avoid interruption of the manufacturing flow. Robotic FSW systems offer the required flexibility to perform such repairs. The main objective of this work was to conduct a preliminary investigation on the microstructural, mechanical and toughness properties of robotic friction stir repair welds. To achieve this objective defective welds have been purposely produced and subsequently repaired. Specimens for microstructural analysis, mechanical and fracture toughness testing have been obtained from repaired and defect-free welds as well as from the base plate for comparison purposes. The mechanical properties have been established using standard tests, i.e. hardness, bending and tensile. Toughness properties of the joints have been determined using small (compact tension - CT) and large (M(T)) scale specimens. Fatigue pre-cracks were positioned in the nugget and HAZ. Crack resistance curves (R-Curves) were determined using the potential drop technique. The obtained results indicated that the additional thermal cycle and deformation process imposed by the repair weld did not adversely affect the mechanical and toughness properties of the nugget area. Both defect-free and repair welds showed higher toughness than the base material. Pre-cracks positioned in the nugget region were deviated into the lower strength TMAZ after initiation and ductile crack growth within the nugget area due to strength undermatch. Later propagation remained within the TMAZ. (orig.) [German] Das Schweissen von Elementen oder Strukturen kann eine lokale Reparatur erfordern, wenn durch den Fuegeprozess ausgeloeste Fehler auftreten. Vorteilhafterweise sollten die Reparaturen ausserhalb der Fertigungslinie erfolgen, um den Produktionsablauf nicht zu stoeren. Robotergestuetzte FSW-Systeme bieten die benoetigte

  4. Final report on characterization of physical and mechanical properties of copper and copper alloys before and after irradiation. (ITER R and D Task no. T213)

    Energy Technology Data Exchange (ETDEWEB)

    Singh, B.N.; Taehtinen, S. [VTT Manufacturing Technology (Finland)

    2001-12-01

    The present report summarizes and highlights the main results of the work carried out during the last 5 - 6 years on effects of neutron irradiation on physical and mechanical properties of copper and copper alloys. The work was an European contribution to ITER Research and Development programme and was carried out by the Associations Euratom - Risoe and Euratom - Tekes. Details of the investigations carried out within the framework of the present task and the main results have been reported in various reports and journal publication. On the basis of these results some conclusions are drawn regarding the suitability of a copper alloy for its use in the first wall and divertor components of ITER. It is pointed out that the present work has managed only to identify some of the critical problems and limitations of the copper alloys for their employment in the hostile environment of 14 MeV neutrons. A considerable amount of further effort is needed to find a realistic and optimum solution. (au)

  5. Novel copper-based therapeutic agent for anti-inflammatory: synthesis, characterization, and biochemical activities of copper(II) complexes of hydroxyflavone Schiff bases.

    Science.gov (United States)

    Joseph, J; Nagashri, K

    2012-07-01

    Four hydroxyflavone derivatives have been synthesized with the aim of obtaining a good model of superoxide dismutase. Better to mimic the natural metalloenzyme, copper complexes have been designed. The Cu(II) complexes of general formulae, [CuL] where L = 5-hydroxyflavone-o-phenylenediamine (L¹H₂)/m-phenylenediamine (L²H₂) and 3-hydroxyflavone-o-phenylenediamine (L³H₂)/m-phenylenediamine (L⁴H₂) have been synthesized. The structural features have been determined from their analytical and spectral data. All the Cu(II) complexes exhibit square planar geometry. Redox behavior of copper complexes was studied and the present ligand systems stabilize the unusual oxidation state of the copper ion during electrolysis. The in vitro antimicrobial activities of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola, and Candida albicans. Superoxide dismutase and anti-inflammatory activities of the copper complexes have also been measured and discussed.

  6. Synthesis and characterization of mononuclear copper(II complex of tetradentate N2S2 donor set and the study of DNA and bovine serum albumin binding

    Directory of Open Access Journals (Sweden)

    Sandipan Sarkar

    2014-12-01

    Full Text Available One mononuclear copper(II complex, containing neutral tetradentate NSSN-type ligands, of formulation [Cu II(L 1Cl]ClO 4 (1, was synthesized and isolated in pure form [where L 1˭ 1,3-bis(3-pyridylmethylthiopropane]. Green-colored copper(II complex was characterized by physicochemical, spectroscopic methods and conductivity measurement. These experimental data matched well with the proposed structure of the complex. Biological activity of the complex (1 toward calf thymus DNA and bovine serum albumin has been examined systematically and groove-binding behavior of the Copper(II complex 1 with calf thymus DNA has been observed from the spectral study.

  7. Characterization of hafnium oxide resistive memory layers deposited on copper by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, B.D.; Bishop, S.M. [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States); Leedy, K.D. [Air Force Research Laboratory, 2241 Avionics Circle, Wright Patterson Air Force Base, Dayton, OH 45433 (United States); Cady, N.C., E-mail: ncady@albany.edu [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States)

    2014-07-01

    Hafnium oxide-based resistive memory devices have been fabricated on copper bottom electrodes. The HfO{sub x} active layers in these devices were deposited by atomic layer deposition (ALD) at 250 °C with tetrakis(dimethylamido)hafnium(IV) as the metal precursor and an O{sub 2} plasma as the reactant. Depth profiles of the HfO{sub x} by X-ray photoelectron spectroscopy and secondary ion mass spectroscopy revealed a copper concentration on the order of five atomic percent throughout the HfO{sub x} film. In addition to the Cu doped HfO{sub x}, a thin layer (20 nm) of Cu{sub x}O is present at the surface. This surface layer is believed to have formed during the ALD process, and greatly complicates the analysis of the switching mechanism. The resistive memory structures fabricated from the ALD HfO{sub x} exhibited non-polar resistive switching, independent of the top metal electrode (Ni, Pt, Al, Au). Resistive switching current voltage (I–V) curves were analyzed using Schottky emission and ionic hopping models to gain insight into the physical mechanisms underpinning the device behavior. During the forming process it was determined that, at voltages in excess of 2.5 V, an ionic hopping model is in good agreement with the I–V data. The extracted ion hopping distance ∼ 4 Å was within the range of interatomic spacing of HfO{sub 2} during the forming process consistent with ionic motion of Cu{sup 2+} ions. Lastly the on state I–V data was dominated at larger voltages by Schottky emission with an estimated barrier height of ∼ 0.5 eV and a refractive index of 2.59. The consequence of the Schottky emission analysis indicates the on state resistance to be a product of a Pt/Cu{sub 2}O/Cu filament(s)/Cu{sub 2}O/Cu structure. - Highlights: • HfO{sub 2} was grown via atomic layer deposition at 250 and 100 °C on Cu substrates. • A Cu{sub 2}O surface layer and Cu doping were observed in post-deposition of HfO{sub 2}. • Resistive memory devices were fabricated and

  8. Synthesis, spectroscopic characterization, crystallographic studies and antibacterial assays of new copper(II) complexes with sulfathiazole and nimesulide

    Science.gov (United States)

    Nunes, Julia Helena Bormio; de Paiva, Raphael Enoque Ferraz; Cuin, Alexandre; da Costa Ferreira, Ana Maria; Lustri, Wilton Rogério; Corbi, Pedro Paulo

    2016-05-01

    New ternary copper(II) complexes of sulfathiazole (SFT, C9H8N3O2S2) or nimesulide (NMS, C13H11N2O5S) and 2,2‧-bipyridine (bipy) were synthesized, and characterized by chemical and spectroscopic techniques. Elemental analyses indicated a 2:1:1 sulfonamide/copper/bipy composition for both complexes. Mass spectrometric measurements permitted identifying the molecular ions [Cu(SFT)2(bipy)+H]+ and [Cu(NMS)2(bipy)+H]+ at m/z 728 and 835, respectively, confirming the proposed compositions. Crystal structure of the [Cu(SFT)2(bipy)] complex was solved by powder X-ray diffraction analysis (PXRD), attesting that the Cu(II) ion is hexacoordinated in a distorted octahedral geometry. Each SFT molecule coordinates to the metal ion by the nitrogen atoms of the SO2-N group and of the heterocyclic ring. The coordination sphere is completed by a bipyridine. Electronic paramagnetic resonance (EPR) studies were carried out for the [Cu(NMS)2(bipy)] complex, indicating a tetragonal environment around the metal ion. It was suggested that NMS coordinates to Cu(II) by the nitrogen and oxygen atoms of the SO2-N group, which was confirmed by infrared spectroscopic studies. Biological studies showed the antibacterial activity of both Cu-SFT and Cu-NMS complexes, with the minimum inhibitory concentration (MIC) values ranging from 0.10 to 0.84 mmol L-1 against Gram-negative bacteria for [Cu(SFT)2(bipy)], and from 1.50 to 3.00 mmol L-1 against Gram-positive and -negative bacteria for [Cu(NMS)2(bipy)].

  9. Mixed-ligand copper(II) phenolate complexes: Synthesis, spectral characterization, phosphate-hydrolysis, antioxidant, DNA interaction and cytotoxic studies

    Science.gov (United States)

    Gurumoorthy, Perumal; Mahendiran, Dharmasivam; Prabhu, Durai; Arulvasu, Chinnasamy; Rahiman, Aziz Kalilur

    2015-01-01

    A series of phenol-based mixed-ligand copper(II) complexes of the type [CuL1-4(diimine)] (1-8), where L1-4 = N1,N2-bis(5-substituted-2-hydroxybenzylidene)-1,2-ethylene/phenylenediimine and diimine = 2,2‧-bipyridyl (bpy) or 1,10-phenanthroline (phen), have been isolated and fully characterized by analytical and spectral techniques. Electronic spectra of complexes suggest Cu(II) cation has a d9 electronic configuration, adopting distorted octahedral geometry with axial elongation, due to Jahn-Teller effect. Electrochemical studies of complexes evidenced one-electron irreversible reduction wave in the cathodic region. The observed rate constant (k) values for the hydrolysis of 4-nitrophenylphosphate (4-NPP) are in the range of 0.25-3.82 × 10-2 min-1. The obtained room temperature magnetic moment values (1.79-1.90 BM) lies within the range observed for octahedral copper(II) complexes. Antioxidant studies revealed that these complexes possess considerable radical scavenging potency against DPPH. The binding studies of complexes with calf thymus DNA (CT-DNA) revealed intercalation with minor-groove binding, and the complex 4 exhibits highest binding activity than the other complexes. The cleavage activity on supercoiled pBR322 DNA revealed the involvement of hydroxyl radical and singlet-oxygen as reactive oxygen species, and complexes encourage binding to minor-groove. Further, the cytotoxicity of complex 4 on human hepatocellular liver carcinoma HepG2 cell line implies the cell death through apoptosis.

  10. Investigation on risk factors and morbidity of FSW sexually transmitted disease%FSW性病患病率及行为危险因素调查

    Institute of Scientific and Technical Information of China (English)

    陈美玲; 余克西; 叶永茂; 杨海清

    2011-01-01

    Objective In order to learn about the FSW acceptance of health services in Maoming city, risk factors of behavior, sexually transmitted disease ( syphilis, clap, genital chlamydia trachomatis infection ) and HIV infection status. Methods On the premise of informed consent, the crowd of FSW received face-to-face questionnaire investigation and sampling testing. Results 84.5% of the FSW crowd come from other provinces, 90.6% of their education degree does not exceed junior high school, in the latest year 0.9% of the FSW had drug behavior, in the most recent month 65.99% of the FSW has insisted to use condoms, 4.63% of the FSW has been syphilis antibody TRUST positive, 6.96% of the FSW has been neisseria gonorrhoeae infection positive, 17.39%of the FSW has been positive for chlamydia trachomatis infection. Conclusion FSW venereal infection rates are higher in Maoming, with widespread STD/AIDS behavior, AIDS knowledge propaganda education and behavior intervention work according to the FSW are favorable measures to control AIDS from spreading to the general population.%目的 为了解本地区的FSW接受健康服务情况、行为危险水平和性病(梅毒、淋病、生殖道沙眼衣原体感染)、艾滋病感染状况.方法 在知情同意的前提下,对FSW人群进行面对面的问卷调查及采样检测.结果 84.5%FSW人群来自外省,90.6%文化程度不超过初中,最近1年0.9%FSW有吸毒行为,最近1个月有65.99%FSW坚持使用安全套,4.63%FSW梅毒抗体TRUST阳性,6.96%FSW淋球菌感染阳性,17:39%FSW沙眼衣原体感染阳性.结论 本地区FSW性病感染率较高,传播性病和艾滋病的行为普遍;针对FSW大力开展预防性病、艾滋病知识宜传教育和行为干预工作,是控制艾滋病通过FSW向一般人群传播的有利措施.

  11. Structural and magnetic characterization of copper sulfonated phthalocyanine grafted onto treated polyethylene

    Science.gov (United States)

    Reznickova, A.; Kolska, Z.; Orendac, M.; Cizmar, E.; Sajdl, P.; Svorcik, V.

    2016-08-01

    This study focuses on high density polyethylene (HDPE) activated by Ar plasma treatment, subsequently grafted with copper sulfonated phthalocyanine (CuPc) especially pointing out to the surface and magnetic properties of those composites. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, zeta potential and by electron spin resonance (ESR). XPS analysis confirmed the successful grafting of phthalocyanine. The highest absorption was found for the sample grafted with bCuPc for 1 h. Electrokinetic analysis also confirmed the plasma treatment and also subsequent CuPc grafting influence significantly the surface chemistry and charge. These results correspond well with XPS determination. ESR studies confirmed the presence of CuPc grafted on HDPE. It was found, that grafting is mediated by magnetically inactive functional groups, rather than radicals. Magnetic properties of CuPc do not seem to change significantly after grafting CuPc on polyethylene surface.

  12. Characterization of Phases in an As-cast Copper-Manganese-Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    J.Iqbal, F.Hasan; F.Ahmad

    2006-01-01

    Copper-manganese-aluminum (CMA) alloys, containing small additions of Fe, Ni, and Si, exhibit good strength and remarkable corrosion resistance against sea water. The alloys are used in as-cast condition, and their microstructure can show wide variations. The morphology, crystallography and composition of the phases presented in an as-cast (CMA) alloy of nominal composition Cu-14%Mn-8%Al-3%Fe-2%Ni were investigated using optical, electron optical, and microprobe analytical techniques. The as-cast microstructure consisted of the grains of fcc α and bcc β-phases alongwith intermetallic precipitates of various morphologies. The dendritic-shaped particles and the cuboid-shaped precipitates, which were rich in Fe and Mn and had an fcc DO3 structure. These four different morphologies of intermetallic precipitates exhibited discrete orientationrelationships with the α-matrix. The β-grains only contained very small cuboid shaped precipitates, which could only be resolved through transmission electron microscopy. These precipitates were found to be based on Fe3Al and had the DO3 structure.

  13. Synthesis and optical characterization of copper nanoparticles prepared by laser ablation

    Indian Academy of Sciences (India)

    SAMIRA MONIRI; MAHMOOD GHORANNEVISS; MOHAMMAD REZA HANTEHZADEH; MOHSEN ASADI ASADABAD

    2017-02-01

    The remarkable size-tunable properties of nanoparticles (NPs) make them a hot research topic with applications in a wide range of fields. Hence, copper (Cu) colloidal NPs were prepared using laser ablation (Nd:YAG, 1064 nm, 7 ns, 10 Hz, 6000 pulses) of a coppermetal plate at different laser fluences (LFs) in the range of 1–2.5 J cm$^{−2}$ in ethylene glycol (EG), at room temperature. Analysis of NPs was carried using different independent techniques such as ultraviolet–visible (UV–vis) spectroscopy; transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. TEM analysis showed that the NPs were spherical with a bimodal distribution and an average particle size of 5 and 16nm influence of 1.2 J cm$^{−2}$, and 9 and 22 nm at 2 J cm$^{−2}$. The UV–vis spectra of colloidal NPs revealed the maximum absorbance at around 584 nm, indicating the formation of Cu NPs, which supported using FTIR spectra. Furthermore, the absorption spectra confirmed the metallic nature of Cu NPs. FTIR spectroscopy was utilized to verify information about the NPs surface state and chemical bonds constructed in the atom groups apparent on their surface.

  14. Proteome characterization of copper stress responses in the roots of sorghum.

    Science.gov (United States)

    Roy, Swapan Kumar; Cho, Seong-Woo; Kwon, Soo Jeong; Kamal, Abu Hena Mostafa; Lee, Dong-Gi; Sarker, Kabita; Lee, Moon-Soon; Xin, Zhanguo; Woo, Sun-Hee

    2017-09-21

    Copper (Cu) is a important micronutrient for plants, but it is extremely toxic to plants at high concentration and can inactivate and disturb protein structures. To explore the Cu stress-induced tolerance mechanism, the present study was conducted on the roots of sorghum seedlings exposed to 50 and 100 µM CuSO4 for 5 days. Accumulation of Cu increased in roots when the seedlings were treated with the highest concentration of Cu(2+) ions (100 μM). Elevated Cu concentration provoked notable reduction of Fe, Zn, Ca, and Mn uptake in the roots of sorghum seedlings. In the proteome analysis, high-throughput two-dimensional polyacrylamide gel electrophoresis combined with MALDI-TOF-TOF MS was performed to explore the molecular responses of Cu-induced sorghum seedling roots. In two-dimensional silver-stained gels, 422 protein spots were identified in the 2-D gel whereas twenty-one protein spots (≥1.5-fold) were used to analyze mass spectrometry from Cu-induced sorghum roots. Among the 21 differentially expressed proteins, 10 proteins were increased, while 11 proteins were decreased due to the intake of Cu ions by roots of sorghum. Abundance of most of the identified proteins from the roots that function in stress response and metabolism was remarkably enhanced, while proteins involved in transcription and regulation were severely reduced. Taken together, these results imply insights into a potential molecular mechanism towards Cu stress in C4 plant, sorghum.

  15. Synthesis,Structure and Spectral Characterization of a Discrete Binuclear Copper(Ⅱ)Complex

    Institute of Scientific and Technical Information of China (English)

    王瑞虎; 苏伟平; 曹荣; 赵颖隽; 洪茂椿

    2001-01-01

    A discrete bi nuclear copper(Ⅱ)complex containing Cu2 O2 unit has been syntheacterized by X-ray diffraction study and IR spectroscopy.The crystal is monoclinic,space group:P21/n,with unit cell parameters: a=8.2952(2),b=18.4633(3),c=10.5049(2)(A ).β=108.965(1)°,V=1521.56(5)(A)3,Z=2,C22H30N8O10Cl2Cu2,Mr=764.52,Dc=1.669 Mg/m3,F(000)=780,μ(MoKα)=8.60,T=293(2)K,final R=0.0623,wR=0.1536 for 2660 observed reflections with I > 2.0σ(Ⅰ).The centrosymmetric complex Cu2(CH3O)2(C5H6N2)4(ClO4)2 comprises a pair of Cu(Ⅱ)atoms bridged by two methanoxo-and N-coordination 2-aminoppyridine.The Cu(Ⅱ)…Cu(Ⅱ)distance is 3.002(1)(A).

  16. Synthesis and Characterization of Novel Thiourea Derivatives and Their Nickel and Copper Complexes

    Directory of Open Access Journals (Sweden)

    Gün Binzet

    2013-01-01

    Full Text Available New benzoyl thiourea derivatives and their nickel and copper complexes were synthesized. The structure of the synthesized compounds were confirmed by elemental analysis, FT-IR, and 1H NMR techniques. Four of the synthesized compounds are analyzed by X-ray single crystal diffraction technique. Whereas N,N-dimethyl-N′-(4-fluorobenzoylthiourea, N,N-diethyl-N′-(4-fluorobenzoylthiourea, and N,N-di-n-butyl-N′-(4-fluorobenzoyl thiourea crystallize in the monoclinic system, bis(N,N-di-n-propyl-N′-(4-fluorobenzoylthioureato nickel(II complex crystallizes in the triclinic system. These ligand molecules form dimers through strong intermolecular hydrogen bonds such as N–H⋯S, C–H⋯O, and N–H⋯O. Moreover, there are different types of intramolecular interactions in the crystal structures. Bis(N,N-dimethyl-N′-(4-fluorobenzoylthioureato nickel(II complex has a nearly square-planar coordination. The distance of nickel atom from the best plane through the coordination sphere is 0.029 Å.

  17. Synthesis, crystal structures, spectroscopic characterization and in vitro antidiabetic studies of new Schiff base Copper(II) complexes

    Indian Academy of Sciences (India)

    SUNDARAMURTHY SANTHA LAKSHMI; KANNAPPAN GEETHA; M GAYATHRI; GANESH SHANMUGAM

    2016-07-01

    Two new Schiff base copper(II) complexes, [CuL¹(tmen)] (1) and [Cu₂L₂² (tmen)] (2) {where, H₂L¹ = N-(salicylidene)-L-valine, H₂L² = N-(3,5-dichlorosalicylidene)-L-valine and tmen = N,N,N',N'- tetramethylethylene-1,2-diamine} have been synthesized and characterized by molar conductance, elemental analyses, VSM-RT, UV-Vis, FTIR, EPR, and CD spectra. Both the complexes were structurally characterized by single crystal XRD. The crystal structure of complex 1 displays a distorted square pyramidal geometry in which Schiff base is coordinated to the Cu(II) ion via ONO-donor in the axial mode, whereas, the chelating diamine displays axial and equatorial mode of binding via NN-donor atoms. The crystal structure of the complex 2 reveals a syn-anti mode of carboxylate bridged dinuclear complex, in which, the coordination geometry around Cu(1) is square pyramid and distorted square planar around Cu(2). The target complexes were screened for in vitro antidiabetic activity. Both the complexes showed good inhibitory activity for α-amylase and α-glucosidase.

  18. The Effect of Tool Position for Aluminum and Copper at High Rotational Friction Stir Welding

    OpenAIRE

    Recep Çakır; Sare Çelik

    2015-01-01

    Friction Stir Welding (FSW) is a solid state welding process used for welding similar and dissimilar materials. This welding technique allows welding of Aluminum alloys which present difficulties in fusion joining and allows different material couples to be welded continuously. In this study, 1050 aluminum alloy and commercially pure copper to increase heat input were produced at high rotation rate (2440 rev/min) with four different pin position (0-1-1.5-2 mm) and three different weld speeds ...

  19. Influence of FSW pin tool geometry on plastic flow of AA7075 T651

    Science.gov (United States)

    Lertora, Enrico; Mandolfino, Chiara; Gambaro, Carla

    2016-10-01

    In this paper the behaviour of the plastic flow during Friction Stir Welding of AA7075 T651 plates, realized with different shaped tools, has been investigated. In particular, the influence of the shape of three tools was studied using copper strips placed along the welds. After welding, radiography and metallurgical analysis were used in order to investigate the marker movement and its fragmentation.

  20. A new copper(II) Schiff base complex containing asymmetrical tetradentate N2O2 Schiff base ligand: Synthesis, characterization, crystal structure and DFT study

    Science.gov (United States)

    Grivani, Gholamhossein; Baghan, Sara Husseinzadeh; Vakili, Mohammad; Khalaji, Aliakbar Dehno; Tahmasebi, Vida; Eigner, Václav; Dušek, Michal

    2015-02-01

    A new copper (II) Schiff base complex, CuL1, was prepared from the reaction of asymmetrical Schiff base ligand of L1 and Cu(OAC)2 (L1 = salicylidene imino-ethylimino-pentan-2-one). The Schiff base ligand, L1, and its copper (II) complex, CuL1, have been characterized by elemental analysis (CHN) and FT-IR and UV-vis spectroscopy. In addition, 1H NMR was employed for characterization of the ligand. Thermogrametric analysis of the CuL1 reveals its thermal stability and its decomposition pattern shows that it is finally decomposed to the copper oxide (CuO). The crystal structure of CuL1 was determined by the single crystal X-ray analysis. The CuL1 complex crystallizes in the monoclinic system, with space group P21/n and distorted square planar coordination around the metal ion. The Schiff base ligand of L1 acts as a chelating ligand and coordinates via two nitrogen and two oxygen atoms to the copper (II) ion with C1 symmetry. The structure of the CuL1 complex was also studied theoretically at different levels of DFT and basis sets. According to calculated results the Csbnd O bond length of the salicylate fragment is slightly higher than that in the acetylacetonate fragment of ligand, which could be interpreted by resonance increasing between phenyl and chelated rings in ligand in relative to the acetylacetonate fragment.

  1. Further characterization of the process of in vitro uptake of radiolabeled copper by the rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Barnea, A.; Hartter, D.E.; Cho, G.; Bhasker, K.R.; Katz, B.M.; Edwards, M.D. (Univ. of Texas, Dallas (USA))

    1990-10-01

    We have previously demonstrated that hypothalmic slices obtained from adult male rats accumulate {sup 67}Cu by two ligand-dependent, saturable processes: a high and low affinity process. To further establish the generality of these uptake processes, we defined the ligand requirements and the saturation kinetics of {sup 67}Cu uptake by tissue slices obtained from the newborn hypothalamus (HT); adult male hypothalamus, hippocampus, cortex, median eminence, and caudate nucleus; hypothalamus and hippocampus of castrated (14 days) males and of pregnant (19 days) and ovariectomized (14 days) females. It was found that ionic {sup 67}Cu{sup 2}{sup +} was poorly taken up by newborn HT and adult caudate, complexation with His enhanced {sup 67}Cu uptake 3-4-fold, and complexation with albumin inhibited {sup 67}Cu uptake. These ligand requirements are identical to those we have previously shown for the adult HT. When {sup 67}Cu uptake was evaluated under conditions optimal for the high or the low affinity process, for each process the dose response curves generated from these various tissues were very similar. In addition, we assessed the uptake of both components of the CuHis2 complex by incubating tissues with {sup 67}Cu{sup 3 H}-His2 and found that the tissue ratio of {sup 67}Cu:{sup 3}H was a sigmoidal function of the concentration of the Cu complex such that at greater than 5 microM, the ratio was about 3-fold greater than the medium ratio; indicating preferential uptake of {sup 67}Cu relative to {sup 3}H-His. The changes in isotope ratios were observed in newborn HT and adult HT, as well as caudate. These similarities in the ligand requirements and saturation kinetics of {sup 67}Cu uptake establish the generality of these two processes of in vitro uptake of copper in the rat brain.

  2. Synthesis, characterization and electrochemical studies of copper(II complexes derived from succinoyl- and adipoyldihydrazones

    Directory of Open Access Journals (Sweden)

    Aziz Ahmed

    2017-02-01

    Full Text Available The complexes [Cu(H2L]SO4 in which H2L represents H4slsh and H4slah have been prepared and characterized by a variety of physico-chemical techniques. Magnetic and spectral evidences support a square-planar geometry for the complexes. These complexes have been characterized by micro analytical analyses, FT-IR, UV–Vis, CV, and ESR spectroscopy. The electrochemical behaviour of these complexes at a glassy carbon electrode in DMSO solution indicates one electron transfer reduction waves.

  3. Copper(II) Complexes of Phenanthroline and Histidine Containing Ligands: Synthesis, Characterization and Evaluation of their DNA Cleavage and Cytotoxic Activity.

    Science.gov (United States)

    Leite, Sílvia M G; Lima, Luís M P; Gama, Sofia; Mendes, Filipa; Orio, Maylis; Bento, Isabel; Paulo, António; Delgado, Rita; Iranzo, Olga

    2016-11-21

    Copper(II) complexes have been intensely investigated in a variety of diseases and pathological conditions due to their therapeutic potential. The development of these complexes requires a good knowledge of metal coordination chemistry and ligand design to control species distribution in solution and tailor the copper(II) centers in the right environment for the desired biological activity. Herein we present the synthesis and characterization of two ligands HL1 and H2L2 containing a phenanthroline unit (phen) attached to the amino group of histidine (His). Their copper(II) coordination properties were studied using potentiometry, spectroscopy techniques (UV-vis and EPR), mass spectrometry (ESI-MS) and DFT calculations. The data showed the formation of single copper complexes, [CuL1](+) and [CuL2], with high stability within a large pH range (from 3.0 to 9.0 for [CuL1](+) and from 4.5 to 10.0 for [CuL2]). In both complexes the Cu(2+) ion is bound to the phen unit, the imidazole ring and the deprotonated amide group, and displays a distorted square pyramidal geometry as confirmed by single crystal X-ray crystallography. Interestingly, despite having similar structures, these copper complexes show different redox potentials, DNA cleavage properties and cytotoxic activity against different cancer cell lines (human ovarian (A2780), its cisplatin-resistant variant (A2780cisR) and human breast (MCF7) cancer cell lines). The [CuL2] complex has lower reduction potential (Epc= -0.722 V vs -0.452 V for [CuL1](+)) but higher biological activity. These results highlight the effect of different pendant functional groups (carboxylate vs amide), placed out of the coordination sphere, in the properties of these copper complexes.

  4. Characterization of novel thermostable bacterial Laccase-like multi-copper oxidases

    DEFF Research Database (Denmark)

    Brander, Søren; Mikkelsen, Jørn Dalgaard

    cultured from a hot dirt patch in Yellowstone National Park. It belongs to the evolutionary interesting phylum Chloroflexi that has been proposed to represent some of the earliest lifeforms on Earth. The genome of T. terrenum codes for a LMCO, and we have expressed and characterized the enzyme...

  5. Synthesis and Characterization of Binuclear Schiff Base Complexes of Nickel, Copper, and Manganese.

    Science.gov (United States)

    1983-11-04

    D-Ri35 493 SYNTHESIS AND CHRACTERILATION OF BINUCLEAR SCHIFF BASE i/i COMPLEXES OF NICK-.U) ROCHESTER UNIV NV DEPT OF CHEMISTRY B C WHITMIORE ET AL...RESEARCH Contract NOO014-83-K-0154 fl Task No. NR 634-742 TECHNICAL REPORT NO. 1 ,Z Synthesis and Characterization of Binuclear Schiff Base Complexes

  6. Toxicological characterization of bio-active drugs on basis of Iron Fe, Co, and Copper Cu nanopowders

    Science.gov (United States)

    Polishuk, S.; Nazarova, A.; Stepanova, I.

    2015-11-01

    The article presents investigations of toxicological parameters (acute and chronic toxicity, cumulative coefficient) of iron, cobalt, copper and copper oxide nanoparticles with white rats in labs. We have estimated the optimal concentrations of the above mentioned substances with rabbits. We have also studied morphological, physiological and biochemical parameters of the animals when adding the optimal doses to the diet for a long term.

  7. Transcriptomic and physiological characterization of the fefe mutant of melon (Cucumis melo) reveals new aspects of iron-copper crosstalk.

    Science.gov (United States)

    Waters, Brian M; McInturf, Samuel A; Amundsen, Keenan

    2014-09-01

    Iron (Fe) and copper (Cu) homeostasis are tightly linked across biology. In previous work, Fe deficiency interacted with Cu-regulated genes and stimulated Cu accumulation. The C940-fe (fefe) Fe-uptake mutant of melon (Cucumis melo) was characterized, and the fefe mutant was used to test whether Cu deficiency could stimulate Fe uptake. Wild-type and fefe mutant transcriptomes were determined by RNA-seq under Fe and Cu deficiency. FeFe-regulated genes included core Fe uptake, metal homeostasis, and transcription factor genes. Numerous genes were regulated by both Fe and Cu. The fefe mutant was rescued by high Fe or by Cu deficiency, which stimulated ferric-chelate reductase activity, FRO2 expression, and Fe accumulation. Accumulation of Fe in Cu-deficient plants was independent of the normal Fe-uptake system. One of the four FRO genes in the melon and cucumber (Cucumis sativus) genomes was Fe-regulated, and one was Cu-regulated. Simultaneous Fe and Cu deficiency synergistically up-regulated Fe-uptake gene expression. Overlap in Fe and Cu deficiency transcriptomes highlights the importance of Fe-Cu crosstalk in metal homeostasis. The fefe gene is not orthologous to FIT, and thus identification of this gene will provide clues to help understand regulation of Fe uptake in plants.

  8. Synthesis, characterization, cytotoxicity and antiangiogenic activity of copper(II) complexes with 1-adamantoyl hydrazone bearing pyridine rings.

    Science.gov (United States)

    Rodić, Marko V; Leovac, Vukadin M; Jovanović, Ljiljana S; Spasojević, Vojislav; Joksović, Milan D; Stanojković, Tatjana; Matić, Ivana Z; Vojinović-Ješić, Ljiljana S; Marković, Violeta

    2016-06-10

    Three novel copper complexes with tridentate N2O ligand di(2-pyridil) ketone 1-adamantoyl hydrazone (Addpy) of the formula [Cu(II)2Cu(I)2(Addpy)2Br2(μ-Br4)] (1), catena-poly[CuCl(μ-Addpy)(μ-Cl)CuCl2]n (2) and [Cu(Addpy)(NCS)2] (3) were synthesized. Complexes are characterized by X-ray crystallography, spectral (UV-Vis, FTIR), electrochemical (CV) analyses, and magnetochemical measurements. Investigation of anticancer potential of Cu(II) complexes, mode of cell death, apoptosis, and inhibition of angiogenesis were performed. All tested malignant cell lines (HeLa, LS174, A549, K562, and MDA-MB-231) showed high sensitivity to the examined Cu(II) complexes. It has been shown that the complexes induce apoptosis in the caspase 3-dependent manner, whereas the anti-angiogenic effects of 1, 2, and 3 have been confirmed in EA.hy926 cells using a tube formation assay.

  9. Synthesis, characterization, biological studies (DNA binding, cleavage, antibacterial and topoisomerase I) and molecular docking of copper(II) benzimidazole complexes.

    Science.gov (United States)

    Arjmand, Farukh; Parveen, Shazia; Afzal, Mohd; Shahid, Mohd

    2012-09-03

    To explore the therapeutic potential of copper-based benzimidazole complexes, tetranuclear Cu(II) complex 1 and dinuclear ternary amino acid complexes 2 and 3 {L-trp and L-val, respectively} were synthesized and thoroughly characterized. In vitro DNA binding studies of complexes 1-3 were carried out employing UV-vis titrations, fluorescence, circular dichroic and viscosity measurements which revealed that the complexes 1-3 bind to CT DNA preferably via groove binding. Complex 1 cleaved pBR322 DNA via hydrolytic pathway (validated by T4 DNA ligase assay), accessible to major groove while 2 followed oxidative mechanism, binding to minor groove of DNA double helix; binding events were further validated by molecular docking studies. Additionally, the complexes 1 and 2 exhibit high Topo-I inhibitory activity at different concentrations. The complexes 1-3 were evaluated for antibacterial activity against Escherichia coli and Staphylococcus aureus, and 2 was found to be most effective against Gram-positive bacteria.

  10. Polyurethane with Tethered Copper(II)-Cyclen Complex: Preparation, Characterization and Catalytic Generation of Nitric Oxide from S-Nitrosothiols

    Science.gov (United States)

    Hwang, Sangyeul

    2008-01-01

    The preparation and characterization of a commercial biomedical grade polyurethane (Tecophilic, SP-93A-100) material possessing covalently linked copper(II)-cyclen moieties as a nitric oxide (NO) generating polymer are described. Chemiluminescence NO measurements demonstrate that the prepared polymer can decompose endogenous S-nitrosothiols (RSNOs) such as S-nitrosoglutathione and S-nitrosocysteine to NO in the presence of thiol reducing agents (RSHs; e.g., glutathione and cysteine) at physiological pH. Since such RSNO and RSH already exist in blood, the proposed polymer is capable of spontaneously generating NO when in contact with fresh blood. This is demonstrated by utilizing the polymer as an outer coating at the distal end of an amperometric NO sensor to create a device that generates response toward the RSNO species in the blood. This polymer possesses the combined benefits of a commercial biomedical grade polyurethane with the ability to generate biologically active NO when on contact with blood, and thus may serve as a useful coating to improve the hemocompatibility of various medical devices. PMID:18314189

  11. Hydrothermal Synthesis and Characterization of a One-Dimensional Copper(Ⅰ) Halide Cluster with 1,10-Phenanthroline

    Institute of Scientific and Technical Information of China (English)

    YU,Jie-Hui(于杰辉); WANG,Tie-Gang(王铁钢); SHI,Zhan(施展); XU,Ji-Qinf(徐吉庆); CUI,Xiao-Bing(崔小兵); DING,Hong(丁红); JING,Wei-Jie(荆维杰); CHU,De-Qing(储德清); HUA,Jia(华佳); XU,Jia-Ning(徐家宁)

    2002-01-01

    The title compound Cu2Cl2phen (phen= 1, 10-plenanthroline,C12H8N2) 1 was synthesized from CuCl2@2H2O, CuCl and phen by hydrothermal method and its structure was determined by single crystal X-ray analysis. With phen, CuCl forms one-dimensional chains, which conprise two zigzag chains based on fused Cu-X units and connected via covalent bonds. The compound contains two crystallographically unique monovalent copper ions, Cu(1) and Cu(2). The Cu(1) atom in the tetrahedral site, is coordinated to two bridging Cl- and two N atoms in phen. The Cu(2) atom with a slightly distorted triangular planar geometry, is coordinated to three Cl-. The compoumd 1 was crystallized in monoclinic, space group P21/n with a =0.37338(4), b=1.9510(2), c= 1.68008(19) nm, β=95.605 (3)°, R=0.0458, and was characterized by elemental analysis, IR spectrum and TGA analysis.

  12. Solvothermal syntheses and characterization of three new silver(I)/copper(I)-thioarsenates based on As2+/As3+ ions

    Science.gov (United States)

    Yao, Hua-Gang; Tang, Cheng-Fei; An, Yong-Lin; Ou, Zi-Jian; Wu, Guo-Hao; Lan, Pei; Zheng, Yi-Long

    2017-02-01

    Three new silver(I)/copper(I)-thioarsenates KAgAsIIS2 (1), RbCu2AsIIIS3 (2) and RbCu4AsIIIS4 (3) have been solvothermally synthesized and structurally characterized. 1 exhibits a two-dimensional anionic network built up by As-As bond connecting the left- and right-handed helical [AgS2]4- chains, and represents the first examples of thioarsenates(II). The structure of 2 consists of two kinds of helical [Cu2S3]4- chains linked by the arsenic atoms to form double layers with rubidium ions between the layers. Compound 3 is built up of infinite [Cu2S2]2- chain and layered [Cu6As2S6] linked to form a three-dimensional anionic framework, [Cu4AsS4]-, and containing channels in which the rubidium cations reside. The optical properties of 1-3 have been investigated by UV-vis spectroscopy.

  13. Novel aminonaphthoquinone mannich bases derived from lawsone and their copper(II) complexes: synthesis, characterization and antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Amanda P.; Barbosa, Claudia C.; Greco, Sandro J.; Vargas, Maria D. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Quimica; Visentin, Lorenzo C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica; Pinheiro, Carlos B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Fisica; Mangrich, Antonio S. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Centro Politecnico. Dept. de Quimica; Barbosa, Jussara P.; Costa, Gisela L. da [Instituto Oswaldo Cruz, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    A series of novel Mannich bases (HL1-HL13) derived from 2-hydroxy-1,4-naphthoquinone (lawsone), substituted benzaldehydes [C{sub 6}H{sub 2}R{sup 1}R{sup 2}R{sup 3}C(O)H] and various primary amines (NH{sub 2}R{sup 4}, R{sup 4} = n-butyl, benzyl, allyl, 2-furfuryl), and their Cu{sup 2+} complexes, [Cu(L1){sub 2}]-[Cu(L13){sub 2}], have been synthesized and fully characterized by analytical and spectroscopic methods. The structures of complexes 1 (R{sup 1} R{sup 2} = R{sup 3} = H; R{sup 4} = Bu), 2 (R{sup 1} = R{sup 3} = H; R{sup 2} = NO{sub 2}; R{sup 4}= Bu) and 7 (R{sup 1} OH; R{sup 2} = R{sup 3} = H; R{sup 4}= Bu) were determined by single crystal X-ray diffraction studies. All complexes crystallize in centrosymmetric space groups, with a copper atom in the inversion centre. Two L. coordinate through the naphthalen-2-olate oxygen and secondary amine-N atoms, forming six membered chelate rings around the copper atom in a trans-N{sub 2}O{sub 2} environment; spectroscopic data confirm that the other complexes exhibit similar molecular arrangement. The antimicrobial activity of all compounds has been tested on seven different strains of bacteria: Bacillus cereus, Bacillus subtilis, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. In general, Mannich bases were more active than complexes, HL11 (R{sup 1} = OH; R{sup 2} =H; R{sup 3} = Me; R{sup 4}= Bn) and HL13 (R{sup 1} = OH; R{sup 2} = H; R{sup 3} = Br; R{sup 4}= Bn) being the most potent inhibitors. The MIC for the most active compound HL11 against S. Coli was 20 {mu}mol L{sup -1} (8 {mu}g mL{sup -1}), better than Chloramphenicol (90 {mu}mol L{sup -1}) and well below most values reported for other naphthoquinones. (author)

  14. Characterization and metal-induced gene transcription of two new copper zinc superoxide dismutases in the solitary ascidian Ciona intestinalis

    Energy Technology Data Exchange (ETDEWEB)

    Ferro, Diana [Department of Biology, University of Padova, Padova (Italy); Institute for Evolution and Biodiversity, Westfälische Wilhelms-Universität, Münster (Germany); Franchi, Nicola [Department of Biology, University of Padova, Padova (Italy); Department of Biological, Chemical, Pharmaceutical Science and Technology, University of Palermo, Palermo (Italy); Mangano, Valentina [Department of Biological, Chemical, Pharmaceutical Science and Technology, University of Palermo, Palermo (Italy); Bakiu, Rigers [Department of Crop Production, Agricultural University of Tirana, Tirana (Albania); Cammarata, Matteo; Parrinello, Nicolò [Department of Biological, Chemical, Pharmaceutical Science and Technology, University of Palermo, Palermo (Italy); Santovito, Gianfranco, E-mail: gianfranco.santovito@unipd.it [Department of Biology, University of Padova, Padova (Italy); Ballarin, Loriano [Department of Biology, University of Padova, Padova (Italy)

    2013-09-15

    Highlights: •Ciona intestinalis express two copper-zinc superoxide dismutases (Cu,Zn SODs), one extracellular (Ci-SODa) and one intracellular isoform (Ci-SODb). •Promoters contain consensus sequences similar to mammalian MRE. •Metal exposure results in a significant increase of gene transcription: ci-soda is induced especially by copper and zinc, the increase of ci-sodb transcription is more evident after cadmium exposure. •Genes are mostly transcribed in circulating hemocytes and in ovarian follicular cells. -- Abstract: Antioxidant enzymes are known to protect living organisms against the oxidative stress risk, also induced by metals. In the present study, we describe the purification and molecular characterization of two Cu,Zn superoxide dismutases (SODs), referred to as Ci-SODa and Ci-SODb, from Ciona intestinalis, a basal chordate widely distributed in temperate shallow seawater. The putative amino acid sequences were compared with Cu,Zn SODs from other metazoans and phylogenetic analyses indicate that the two putative Ci-SODs are more related to invertebrate SODs than vertebrate ones. Both phylogenetic and preliminary homology modeling analyses suggest that Ci-SODa and Ci-SODb are extracellular and intracellular isoform, respectively. The mRNA of the two Cu,Zn SODs was localized in hemocytes and in ovarian follicular cells, as revealed by in situ hybridization. The time course of SOD mRNA levels in the presence of three different metals showed upregulation of ci-soda and inhibition of ci-sodb. Spectrophotometric analysis confirms the presence of SOD activity in Ciona tissues. Our in silico analyses of the ci-soda promoter region revealed putative consensus sequences similar to mammalian metal-responsive elements (MRE), suggesting that the transcription of these genes directly depends on metals. These data emphasize the importance of complex metal regulation of ci-soda and ci-sodb transcription, as components of an efficient detoxification pathway

  15. Synthesis, spectral characterization, DNA binding ability and antibacterial screening of copper(II) complexes of symmetrical NOON tetradentate Schiff bases bearing different bridges

    Science.gov (United States)

    Bahaffi, Saleh O.; Abdel Aziz, Ayman A.; El-Naggar, Maher M.

    2012-08-01

    A novel series of four copper(II) complexes were synthesized by thermal reaction of copper acetate salt with symmetrical tetradentate Schiff bases, N,N'bis(o-vanillin)4,5-dimethyl-l,2-phenylenediamine (H2L1), N,N'bis(salicylaldehyde)4,5-dimethyl-1,2-phenylenediamine (H2L2), N,N'bis(o-vanillin)4,5-dichloro-1,2-phenylenediamine (H2L3) and N,N'bis(salicylaldehyde)4,5-dichloro-1,2-phenylenediamine (H2L4), respectively. All the new synthesized complexes were characterized by using of microanalysis, FT-IR, UV-Vis, magnetic measurements, ESR, and conductance measurements, respectively. The data revealed that all the Schiff bases (H2L1-4) coordinate in their deprotonated forms and behave as tetradentate NOON coordinated ligands. Moreover, their copper(II) complexes have square planar geometry with general formula [CuL1-4]. The binding of the complexes with calf thymus DNA (CT-DNA) was investigated by UV-Vis spectrophotometry, fluorescence quenching and viscosity measurements. The results indicated that the complexes bind to CT-DNA through an intercalative mode. From the biological activity view, the copper(II) complexes and their parent ligands were screened for their in vitro antibacterial activity against the bacterial species Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosai by well diffusion method. The complexes showed an increased activity in comparison to some standard drugs.

  16. Removal of ammonia from aqueous solutions by catalytic oxidation with copper-based rare earth composite metal materials: catalytic performance, characterization, and cytotoxicity evaluation

    Institute of Scientific and Technical Information of China (English)

    Chang-Mao Hung

    2011-01-01

    Ammonia (NH3) has an important use in the chemical industry and is widely found in industrial wastewater.For this investigation of copper-based rare earth composite metal materials,aqueous solutions containing 400 mg/L of ammonia were oxidized in a batch-bed reactor with a catalyst prepared by the co-precipitation of copper nitrate,lanthanum nitrate and cerium nitrate.Barely any of the dissolved ammonia was removed by wet oxidation without a catalyst,but about 88% of the ammonia was reduced during wet oxidation over the catalysts at 423 K with an oxygen partial pressure of 4.0 MPa.The catalytic redox behavior was determined by cyclic voltammetry (CV).Furthermore,the catalysts were characterized using thermogravimetric analyzer (TGA) and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX),which showed that the catalytic behavior was related to the metal oxide properties of the catalyst.In addition,the copper-lanthanum-cerium composite-induced cytotoxicity in the human lung MRC-5 cell line was tested,and the percentage cell survival was determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetra-zolium (MTS) analysis in vitro.No apparent cytotoxicity was observed when the human lung cells were exposed to the copper-lanthanum-cerium composite.

  17. Novel homo- and hetero-nuclear copper(II) complexes of tetradentate Schiff bases: Synthesis, characterization, solvent-extraction and catalase-like activity studies

    Energy Technology Data Exchange (ETDEWEB)

    Dede, Buelent [Sueleyman Demirel University, Department of Chemistry, Isparta, 32260 (Turkey)], E-mail: dbulent@fef.sdu.edu.tr; Karipcin, Fatma; Cengiz, Mustafa [Sueleyman Demirel University, Department of Chemistry, Isparta, 32260 (Turkey)

    2009-04-30

    Twelve homo- and hetero-nuclear copper(II) complexes of tetradentate Schiff base ligands containing N{sub 4} donor sets have been prepared by employing several steps. The characterization and nature of bonding of the complexes have been deduced from elemental analysis, FT-IR, molar conductivity, magnetic moment measurements and thermal analysis. The three Schiff base ligands were further identified using {sup 1}H and {sup 13}C NMR spectra. All copper(II) complexes are 1:2 electrolytes as shown by their molar conductivities ({lambda}{sub M}) in DMF and paramagnetic. The subnormal magnetic moment values of the di- and tri-nuclear complexes explained by a very strong anti-ferromagnetic interaction. The extraction ability of the ligands has been examined by the liquid-liquid extraction of selected transition metal (Mn{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Cu{sup 2+}, Zn{sup 2+}, Pb{sup 2+}, Cd{sup 2+}, Hg{sup 2+}) cations. The ligands show strong binding ability toward copper(II) ion. Furthermore the homo- and hetero-nuclear copper(II) complexes were each tested for their ability to catalyse the disproportionation of hydrogen peroxide in the presence of the added base imidazole.

  18. Synthesis and characterization of copper complexes of Schiff base derived from isatin and salicylic hydrazide

    Energy Technology Data Exchange (ETDEWEB)

    Lekshmy, R. K., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com; Thara, G. S., E-mail: lekshmyulloor@gmail.com, E-mail: tharapradeepkumar@yahoo.com [Department of Chemistry, University College, Thiruvananthapuram- 695 034, Kerala (India)

    2014-10-15

    A series of novel metal complexes of Schiff base have been prepared by the interaction of Cu(II) with isatin salicylic hydrazide. All the new compounds were characterized by elemental analysis, conductance measurement, magnetic moment determination, IR, UV, NMR, Mass and EPR spectral studies, thermal studies and microbial activities. The results indicate that the ligand acts as a tridentate chelating ligand coordinating through nitrogen and oxygen atoms. The ligand and complexes show inactive against Escherichia coli and active against Staphylococcus aureus and B.substilis. By analyzing the results of spectral, thermal and elemental analysis square planar geometry is proposed for all the complexes.

  19. Microstructural Development in a TRIP-780 Steel Joined by Friction Stir Welding (FSW: Quantitative Evaluations and Comparisons with EBSD Predictions

    Directory of Open Access Journals (Sweden)

    Gladys Perez Medina

    Full Text Available Abstract The present work describes the effect of FSW on the result microstructure in the stir zone (SZ, thermo-mechanically affected zone (TMAZ, heat affected zone (HAZ and base metal (BM of a TRIP-780 steel. X-ray diffraction (XRD, optical microscopy (OM and EBSD were used for determinations retained austenite (RA in the SZ, It was found that the amount of RA developed in SZ was relatively large, (approximately 11% to 15%. In addition, recrystallization and the formation of a grain texture were resolved using EBSD. During FSW, the SZ experienced severe plastic deformation which lead to an increase in the temperature and consequently grain recrystallization. Moreover, it was found that the recrystallized grain structure and relatively high martensite levels developed in the SZ lead to a significant drop in the mechanical properties of the steel. In addition, microhardness profiles of the welded regions indicated that the hardness in both the SZ and TMAZ were relatively elevated confirming the development of martensite in these regions. In particular, to evaluate the mechanical strength of the weld, lap shear tensile test was conducted; exhibited the fracture zone in the SZ with shear fracture with uniformly distributed elongation shear dimples.

  20. The Effect of SiC Particle Addition During FSW on Microstructure and Mechanical Properties of AZ31 Magnesium Alloy

    Science.gov (United States)

    Abbasi, M.; Abdollahzadeh, A.; Bagheri, B.; Omidvar, H.

    2015-12-01

    Welding and joining of magnesium alloys exert a profound effect on magnesium application expansion, especially in ground and air transportations where large-size, complex components are required. Due to specific physical properties of magnesium, its welding requires great control. In general, the solid-state nature of friction stir welding (FSW) process has been found to produce a low concentration of defects. In the current research, specimens from AZ31 magnesium alloy were welded together using the friction stir process with previously inserted SiC powder particles in the nugget zone. In other words, during the FSW process, the pre-placed SiC particles were stirred throughout the nugget zone of the weld. The results indicated that proper values of rotation and translation speeds led to good appearance of weld zone and suitable distribution of SiC particles producing increased weld strength. The comparison of the microstructures and mechanical properties of FS-welded AZ31 with those of FS-welded one using pre-placed SiC particles showed that the addition of SiC particles decreased the grain size and increased the strength and the formability index.

  1. Copper Contamination of Self-Assembled Organic Monolayer Modified Silicon Surfaces Following a "Click" Reaction Characterized with LAPS and SPIM.

    Science.gov (United States)

    Wu, Fan; Zhang, De-Wen; Wang, Jian; Watkinson, Michael; Krause, Steffi

    2017-04-04

    A copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) reaction combined with microcontact printing was used successfully to pattern alkyne-terminated self-assembled organic monolayer-modified silicon surfaces. Despite the absence of a copper peak in X-ray photoelectron spectra, copper contamination was found and visualized using light-addressable potentiometric sensors (LAPS) and scanning photo-induced impedance microscopy (SPIM) after the "click"-modified silicon surfaces were rinsed with hydrochloric acid (HCl) solution, which was frequently used to remove copper residues in the past. Even cleaning with an ethylenediaminetetraacetic acid (EDTA) solution did not remove the copper residue completely. Different strategies for avoiding copper contamination, including the use of bulky chelators for the copper(I) catalyst and rinsing with different reagents, were tested. Only cleaning of the silicon surfaces with an EDTA solution containing trifluoroacetic acid (TFA) after the click modification proved to be an effective method as confirmed by LAPS and SPIM results, which showed the expected potential shift due to the surface charge introduced by functional groups in the monolayer and allowed, for the first time, imaging the impedance of an organic monolayer.

  2. Synthesis and characterization of some heteroleptic copper(II) complexes based on meso-substituted dipyrrins

    Indian Academy of Sciences (India)

    Rakesh Kumar Gupta; Mahendra Yadav; Rampal Pandey; Daya Shankar Pandey

    2011-11-01

    The syntheses and characterizations of meso-substituted dipyrrins, 5-(4-imidazol-1-yl-phenyl)-dipyrromethene (4-impdpm), 5-(4-nitro-imidazol-1-yl-phenyl)-dipyrromethene, (4-nimpdpm), 5-(4-benzimidazol-1-yl-phenyl)-dipyrromethene (4-bimp-dpm) and heteroleptic complexes [Cu3(4-impdpm)2(hfacac)4] 1, [Cu(4-nimpdpm)(acac)] 2, [Cu(4-nimpdpm)(hfacac)] 3, [{Cu(4-bimpdpm)(acac)}] 4 and [{Cu(4-bimpdpm)-(hfacac)}] 5, imparting acetylacetonato (acac) and hexafluoroacetylacetonato (hfacac) groups as co-ligand have been described. The dipyrrins and complexes 1-5 have been characterized by elemental analyses and spectral (IR ESI-MS, NMR, electronic absorption and emission) studies. Crystal structures of 1, 3 and 4 have been authenticated by X-ray single crystal analyses. The reaction between 4-impdpm and Cu(hfacac)2 gave a trimetallic complex, under analogous conditions 4-nimpdpm and 4-bimpdpm reacted with Cu(acac)2 and Cu(hfacac)2·2H2O to afford mononuclear (2, 3) and 1D polymeric (4, 5) complexes.

  3. Synthesis, Characterization and SOD Activities of IP-copper(Ⅱ)-L-amino Acid Complexes

    Institute of Scientific and Technical Information of China (English)

    GU,Qin; LE,Xue-Yi; LIN,Qing-Bin; LIAO,Sheng-Rong; MA,Xue-Dan; FENG,Xiao-Long

    2007-01-01

    Four new ternary complexes: [Cu(IP)(L-Val)(H2O)]ClO4·1.5H2O (1), [Cu(IP)(L-Leu)(H2O)]ClO4 (2), [Cu(IP)(L-Tyr)(H2O)]ClO4·H2O (3) and [Cu(IP)(L-Trp)(H2O)]ClO4·1.5H2O (4) have been synthesized and characterized by elemental analysis, molar conductivity, infrared absorption spectroscopy, electronic absorption spectros-copy and cyclic voltammetry, where IP = imidazo[4,5-f][1,10] phenanthroline, L-Val = L-valinate, L-Leu = L-leucinate, L-Tyr=L-tyrosinate and L-Trp=L-tryptophanate. Complex 3 was structurally characterized by X-ray diffraction method, which crystallizes in orthorhombic space group P21212 in a unit cell of dimensions a = 3.0567(4) nm,b=0.74079(9) nm, c=1.06198(13) nm, V=2.4047(5) nm3, Z=4, μ=0.1084 cm-1. The SOD-like activities of catalytic dismutation of superoxide anions (O2-·) by the complexes were determined by means of modified nitroblue tetrazolium (NET) photoreduction. The IC50 values of complexes 1, 2, 3 and 4 are 0.072, 0.147, 0.429 and 0.264 μmol·L-1, respectively

  4. Copper-containing polyvinyl alcohol composite systems: Preparation, characterization and biological activity

    Science.gov (United States)

    Reza Hajipour, Abdol; Mohammadsaleh, Fatemeh; Reza Sabzalian, Mohammad

    2015-08-01

    The present investigation reports, the complex formation of Cu(II) with polyvinyl alcohol (PVA) and the synthesis of PVA-stabilized Cu2O particles. This PVA-Cu2O composite has been prepared via chemical reduction method using PVA-Cu(II) complex as precursor. At first, Cu(II) ions were stabilized in PVA matrix via complex formation with OH groups; subsequently, this PVA-Cu(II) macromolecular complex as precursor reacted with ascorbic acid as reducing agent at pH=12 to prepare PVA-Cu2O composite. The products were characterized by FTIR, XRD, FE-SEM, HRTEM, Visible Spectroscopy and atomic absorption. In the following, the antibacterial properties of as-prepared composites were examined against Gram-positive (Bacillus thuringiensis) and Gram-negative bacteria (Escherichia coli), and the results showed excellent antibacterial activity of these materials.

  5. Synthesis, Spectroscopy, and Magnetic Characterization of Copper(II) and Cobalt(II) Complexes with 2-Amino-5-bromopyridine as Ligand

    OpenAIRE

    Arab Ahmadi, Raziyeh; Hasanvand, Farshideh; Bruno, Giuseppe; Amiri Rudbari, Hadi; Amani,Saeid

    2013-01-01

    The synthesis, spectroscopic, and magnetic characterization of two new copper(II) and cobalt(II) complexes are described. Both two compounds have the general formula [M(L)2(Cl)2], in which L= 2-amino-5-bromopyridine. These complexes were prepared in one-step synthesis and characterized by elemental analysis, FTIR, UV-Vis, and EPR spectroscopy. Moreover, the single crystal structure of complex (1) was studied by the X-ray diffraction method. This compound consists of mononuclear units consisti...

  6. Microscale characterization of metallic coatings for a high strength high conductivity copper alloy

    Science.gov (United States)

    Jain, Piyush

    NiCrAlY overlay coatings are being considered by NASA's Glenn Research Center to prevent blanching and reduce thermo-mechanical fatigue of rocket engine combustion chamber liners made of GRCop-84 (Cu-8%Cr-4%Nb) for reusable launch vehicles (RLVs). However, their successful application depends upon their integrity to the GRCop-84 during multiple firings of rocket engines. This study focuses on determining the adhesion of NiCrAlY coatings and their microstructural stability on GRCop-84 as a function of thermal cycling. Specimens were prepared by depositing NiCrAlY top coat on GRCop-84 by vacuum plasma spaying with a thin layer of Cu-26Cr as a bond coat. A thermal cycling rig was built to thermally cycle the NiCrAlY/Cu-26Cr/GRCop-84 specimens from RT to 600°C in an argon environment, with 10 minutes hold at 600°C, and 4 minutes hold at RT. Samples were cut from the coupons in as-received condition (AR), after 100 thermal cycles (TC-100), and after 300 thermal cycles (TC-300) for characterization. A newly developed interfacial microsample testing technique was employed to determine the adhesion of the coatings on GRCop-84, where bowtie shaped microsamples having interfaces normal to the tensile axis were tested. Interfacial microsamples of NiCrAlY/Cu-26Cr/GRCop-84 in all the conditions (AR, TC-100, and TC-300) failed cohesively in the substrate at a UTS of 380+/-5 MPa and their interfaces remained intact. The microstructural characterization revealed that microstructure of the NiCrAlY/Cu-26Cr/GRCop-84 specimens does not degrade as a function of thermal cycling. Constitutive properties of NiCrAlY, Cu-26Cr, and GRCop-84 were measured by testing monolithic samples and were used to build the finite element model (FEM) of the interfacial microsamples. The FE model analyzed the local stress-strain in the interfacial microsamples during the testing and confirmed the strength of the interfaces to be higher than 380+/-5 MPa. Depleted zones, devoid of Cr2Nb particles, were

  7. Potentiel du FSW pour la conception et réalisation de pièces moulées multimatériaux de forme complexe

    OpenAIRE

    ZIMMER-CHEVRET, Sandra; LANGLOIS, Laurent; LAYE, Julien; Goussain, Jean-Claude; GUYOMARD, Claude; Martin, Patrick; Bigot, Régis

    2009-01-01

    National audience; Le soudage par friction malaxage (FSW) est un procédé de soudage de proche en proche à l’état solide. Ceci permet d’éviter la formation de certains défauts apparaissant lors de la solidification en soudage par fusion comme les fissures à chaud ou les soufflures. Dans le cas des alliages d’aluminium, ceci offre de grandes possibilités comme le soudage des alliages des séries 2000 (Al-Cu) et 7000 (Al-Zn) ainsi que les alliages de fonderie. En FSW, l’énergie de soudage est pro...

  8. Potentiel du FSW pour la conception et réalisation de pièces moulées multimatériaux de forme complexe

    OpenAIRE

    ZIMMER-CHEVRET, Sandra; LANGLOIS, Laurent; LAYE, Julien; Goussain, Jean-Claude; GUYOMARD, Claude; Martin, Patrick; Bigot, Régis

    2009-01-01

    Le soudage par friction malaxage (FSW) est un procédé de soudage de proche en proche à l’état solide. Ceci permet d’éviter la formation de certains défauts apparaissant lors de la solidification en soudage par fusion comme les fissures à chaud ou les soufflures. Dans le cas des alliages d’aluminium, ceci offre de grandes possibilités comme le soudage des alliages des séries 2000 (Al-Cu) et 7000 (Al-Zn) ainsi que les alliages de fonderie. En FSW, l’énergie de soudage est produite par le travai...

  9. Synthesis, characterization, and photoactivated DNA cleavage by copper (II)/cobalt (II) mediated macrocyclic complexes.

    Science.gov (United States)

    Naik, H R Prakash; Naik, H S Bhojya; Aravinda, T; Lamani, D S

    2010-01-01

    We report the synthesis of new photonuclease consisting of two Co(II)/Cu(II) complexes of macrocyclic fused quinoline. Metal complexes are [MLX(2)], type where M = Co(II) (5), Cu(II) (6), and X = Cl, and are well characterized by elemental analysis, Fourier transform infrared spectroscopy, (1)H-NMR and electronic spectra. We have shown that photocleavage of plasmid DNA is markedly enhanced when this ligand is irradiated in the presence of Cu(II), and more so than that of cobalt. The chemistry of ternary and binary Co(II) complexes showing efficient light induced (360 nm) DNA cleavage activity is summarized. The role of the metal in photoinduced DNA cleavage reactions is explored by designing complex molecules having macrocyclic structure. The mechanistic pathways are found to be concentration dependent on Co(II)/Cu(II) complexes and the photoexcitation energy photoredox chemistry. Highly effective DNA cleavage ability of 6 is attributed to the effective cooperation of the metal moiety.

  10. Preparation and characterization of nanocomposite between poly(aniline-co-m-chloroaniline)-copper sulfide nanoparticles

    Science.gov (United States)

    Abbas, Saeed J.; Rani, Mamta; Tripathi, S. K.

    2014-06-01

    One dimensional nanostructures of poly(aniline-co-m-chloroaniline) nanocomposite (NC) with CuS nanoparticles (NPs) are prepared by template free method. CuS NPs are prepared by chemical method by using trisodium nitilotriacetate acid as a complexing agent. The materials are characterized by X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Ultraviolet spectroscopy (UV-Vis), photoluminescence (PL) spectroscopy and thermogravimetric analysis (TGA). The hexagonal structure of CuS NPs is confirmed from XRD results with lattice parameters, a=3.78 Å and c=16.288 Å. The diameter of CuS NPs is found to be 16 nm from TEM measurements. Different shapes such as NPs, nanorods and nanotubes structures are observed for poly(aniline-co-m-chloroaniline) whereas its NC with CuS NPs have nanorod and nanotube shapes. Significant shift in the absorption edge of CuS NC is observed in comparison with copolymer and CuS NPs. Also the thermal stability of CuS NC is improved as compared with a copolymer and CuS NPs.

  11. Preparation and characterization of nanocomposite between poly(aniline-co-m-chloroaniline)–copper sulfide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, Saeed J.; Rani, Mamta; Tripathi, S.K., E-mail: surya@pu.ac.in

    2014-06-15

    One dimensional nanostructures of poly(aniline-co-m-chloroaniline) nanocomposite (NC) with CuS nanoparticles (NPs) are prepared by template free method. CuS NPs are prepared by chemical method by using trisodium nitilotriacetate acid as a complexing agent. The materials are characterized by X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Ultraviolet spectroscopy (UV-Vis), photoluminescence (PL) spectroscopy and thermogravimetric analysis (TGA). The hexagonal structure of CuS NPs is confirmed from XRD results with lattice parameters, a=3.78 Å and c=16.288 Å. The diameter of CuS NPs is found to be 16 nm from TEM measurements. Different shapes such as NPs, nanorods and nanotubes structures are observed for poly(aniline-co-m-chloroaniline) whereas its NC with CuS NPs have nanorod and nanotube shapes. Significant shift in the absorption edge of CuS NC is observed in comparison with copolymer and CuS NPs. Also the thermal stability of CuS NC is improved as compared with a copolymer and CuS NPs.

  12. Synthesis and characterization of a tetranuclear copper(Ⅱ) complex with a chiral Schiff base ligand

    Institute of Scientific and Technical Information of China (English)

    Hua Xiang; Long Jiang; Huan-Yong Li; Xiao-Dan Zheng; YU Li

    2013-01-01

    The title complex l-[CuⅡ4(Hvap)2(vap)2(MeOH)2](ClO4)2 1 has been synthesized and characterized by EA,IR,TGA,solid-state CD spectra and X-ray single-crystal analyses (I-H2vap:a Schiff base ligand derived from the condensation of o-vanillin and 1-2-amino-3-phenyl-1-propanol).Complex 1 crystallizes in monoclinic system,chiral space group P21 with a=10.4257(18),b=21.695(4),c=15.721(3) (A),β =94.443(3)°,V=3545.1 (11) (A)3,Z =2,Cu4C7oH78N4O22Cl2,Mr =1652.42,Dc =1.548 g/cm3,F(0 0 0) =1704 and μ(MoKα) =1.338 mm-1.The final R =0.0682 and wR =0.1420 for 6170 observed reflections with I > 2σ(Ⅰ) and R =0.1775 and wR =0.1830 for all data.The structure of complex 1 contains a boat-shaped {Cu4O4} motif.The solid-state CD spectra confirm the chiral nature of complex 1.

  13. Synthesis, characterization and cyclic voltammetric study of copper(II) and nickel(II) polymer chelates.

    Science.gov (United States)

    Azmeera, Venkanna; Rastogi, Pankaj Kumar; Adhikary, Pubali; Ganesan, Vellaichamy; Krishnamoorthi, S

    2014-09-22

    Graft copolymers based on dextran (Dx) and 2-acrylamido-2-methyl-1-propane sulphonic acid (AMPS) were synthesized by free radical initiated solution polymerization technique using ceric ammonium nitrate as initiator. These graft copolymers were used to prepare Cu(II) and Ni(II) chelates by reactions with Cu(II) and Ni(II) metal ions respectively. Graft copolymer and metal chelates were characterized by elemental analysis, intrinsic viscosity, FT-IR, scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and powder X-ray diffraction (XRD). Elemental analysis, intrinsic viscosity and FT-IR studies revealed the incorporation of metal ions to form metal chelates. SEM studies showed the change in morphology due to metal incorporation. From AFM studies it was observed that there was increase in Root mean square (RMS) roughness values in case of metal complexes. Metal chelates were observed to be thermally more stable than graft copolymer from TGA. UV-vis spectroscopy study revealed increase in absorbance values and cyclic voltammetric (CV) studies showed more than tenfold increase in redox current due to formation of Cu(II) and Ni(II) metal chelates. The binding constants of each complex determined by using UV-visible spectroscopy revealed that Cu(II) has more binding ability than Ni(II).

  14. New copper(II) complexes with dopamine hydrochloride and vanillymandelic acid: Spectroscopic and thermal characterization

    Science.gov (United States)

    Mohamed, Gehad G.; Nour El-Dien, F. A.; El-Nahas, R. G.

    2011-10-01

    The dopamine derivatives participate in the regulation of wide variety of physiological functions in the human body and in medication life. Increase and/or decrease in the concentration of dopamine in human body reflect an indication for diseases such as Schizophrenia and/or Parkinson diseases. The Cu(II) chelates with coupled products of dopamine hydrochloride (DO.HCl) and vanillymandelic acid (VMA) with 4-aminoantipyrine (4-AAP) are prepared and characterized. Different physico-chemical techniques namely IR, magnetic and UV-vis spectra are used to investigate the structure of these chelates. Cu(II) forms 1:1 (Cu:DO) and 1:2 (Cu:VMA) chelates. DO behave as a uninegative tridentate ligand in binding to the Cu(II) ion while VMA behaves as a uninegative bidentate ligand. IR spectra show that the DO is coordinated to the Cu(II) ion in a tridentate manner with ONO donor sites of the phenolic- OH, -NH and carbonyl- O, while VMA is coordinated with OO donor sites of the phenolic- OH and -NH. Magnetic moment measurements reveal the presence of Cu(II) chelates in octahedral and square planar geometries with DO and VMA, respectively. The thermal decomposition of Cu(II) complexes is studied using thermogravimetric (TG) and differential thermal analysis (DTA) techniques. The activation thermodynamic parameters, such as, energy of activation, enthalpy, entropy and free energy change of the complexes are evaluated and the relative thermal stability of the complexes are discussed.

  15. Copper(I Complexes of Mesoionic Carbene: Structural Characterization and Catalytic Hydrosilylation Reactions

    Directory of Open Access Journals (Sweden)

    Stephan Hohloch

    2015-04-01

    Full Text Available Two series of different Cu(I-complexes of “click” derived mesoionic carbenes are reported. Halide complexes of the type (MICCuI (with MIC = 1,4-(2,6-diisopropyl-phenyl-3-methyl-1,2,3-triazol-5-ylidene (for 1b, 1-benzyl-3-methyl-4-phenyl-1,2,3-triazol-5-ylidene (for 1c and cationic complexes of the general formula [Cu(MIC2]X (with MIC =1,4-dimesityl-3-methyl-1,2,3-triazol-5-ylidene, X = CuI2− (for 2á, 1,4-dimesityl-3-methyl-1,2,3-triazol-5-ylidene, X = BF4− (for 2a, 1,4-(2,6-diisopropylphenyl-3-methyl-1,2,3-triazol-5-ylidene, X = BF4− (for 2b, 1-benzyl-3-methyl-4-phenyl-1,2,3-triazol-5-ylidene, X = BF4− (for 2c have been prepared from CuI or [Cu(CH3CN4](BF4 and the corresponding ligands, respectively. All complexes were characterized by elemental analysis and standard spectroscopic methods. Complexes 2á and 1b were studied by single-crystal X-ray diffraction analysis. Structural analysis revealed 2á to adopt a cationic form as [Cu(MIC2](CuI2 and comparison of the NMR spectra of 2á and 2a confirmed this conformation in solution. In contrast, after crystallization complex 1b was found to adopt the desired neutral form. All complexes were tested for the reduction of cyclohexanone under hydrosilylation condition at elevated temperatures. These complexes were found to be efficient catalysts for this reaction. 2c was also found to catalyze this reaction at room temperature. Mechanistic studies have been carried out as well.

  16. Copper hypersensitivity.

    Science.gov (United States)

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

    2014-10-01

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

  17. Preparation and characterization of copper nanoparticles encapsulated inside ZSM-5 zeolite and NO adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Othman Ali, Ibraheem [Faculty of Science, Chemistry Department, Al-Azhar University, Nasr City 11884, Cairo (Egypt)], E-mail: iothmana@yahoo.com

    2007-06-25

    The hydrothermal synthesis of Cu-modified ZSM-5 by introducing Cu ions during zeolite synthesis (Cu/ZSM-5{sub in}) and by conventional impregnation (Cu/ZSM-5{sub imp}) has been compared. The catalysts were characterized by X-ray diffraction (XRD), FTIR spectroscopy in the T-O-T vibrations rang, scanning electron microscope (SEM), FTIR of pyridine adsorption and N{sub 2} adsorption. They were subjected to FTIR of NO adsorption for evaluating reactivity of Cu species changed with preparation method. The heterogeneous nature of Cu/ZSM-5{sub imp} is stressed with preponderance of CuO particles on the external zeolite surface. Contrary to this result, Cu/ZSM-5{sub in} showed evidence for highly dispersed and isolated Cu{sup 2+} centers in coordination with lattice oxygen of zeolite. Results of NO-FTIR experiments showed a clear performance for direct NO dissociation where Cu/ZSM-5{sub in} is favored over Cu/ZSM-5{sub imp}. This result, however, appears to correlate with the nature of Cu ions in the samples. The tetrahedral geometry of Cu{sup 2+} ions in the lattice of Cu/ZSM-5{sub in} served in a noticeable development of Broensted acid sites (BAS) compared with analogies on Cu/ZSM-5{sub imp}. The nitrosyl complexes observed over Cu/ZSM-5{sub in} were N{sub 2}O, NO-Cu{sup 2+}, O-NO {sup {delta}}{sup +}, NO{sub 2} {sup -} and mono- and bidentate NO{sub 3} {sup -}. Similar species were observed on Cu/ZSM-5{sub imp}, together with evidence for concurrent appearance of two spectral features due to stable NO{sub 3} {sup -} species at 1713 and 1327 cm{sup -1}. When these results are compared with those obtained over parent ZSM-5 and Cu/ZSM-5{sub in}, the latter species is associated mainly with the Cu{sup 2+} ions in discrete CuO phase which led to deactivation of Cu/ZSM-5{sub imp}.

  18. 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.

  19. Characteristics of Dissimilar FSW Welds of Aluminum Alloys 2017A and 7075 on the Basis of Multiple Layer Research

    Science.gov (United States)

    Mroczka, Krzysztof; Wójcicka, Anna; Pietras, Adam

    2013-09-01

    This work is concerned with the structure of the FSW joint of 2017A/7075 aluminum alloys, which was analyzed on the basis of a number of longitudinal and cross-sectional sections. Various ways and degrees of alloy stirring were identified, depending on the distance from the face of the weld. Furthermore, considerable variation in the length of the weld microstructures was demonstrated, reflecting the variability of the welding process. Studies of mechanical properties are also presented—the distributions of hardness on individual layers. A significant effect of plastic deformation on the hardness of the alloy 7075, which strengthened in deformed areas and shows weakness in the heat-affected zone, was noticed. The influence of the weld structure on the fracture of the sample, which was broken in the static tensile test, was analyzed applying scanning electron microscopy. The presence of non-deformed areas was revealed within the ductile fracture of the sample.

  20. Tethering Growth Factors to Collagen Surfaces Using Copper-Free Click Chemistry: Surface Characterization and in Vitro Biological Response.

    Science.gov (United States)

    Lee, Hyun Jong; Fernandes-Cunha, Gabriella M; Putra, Ilham; Koh, Won-Gun; Myung, David

    2017-07-19

    Surface modifications with tethered growth factors have mainly been applied to synthetic polymeric biomaterials in well-controlled, acellular settings, followed by seeding with cells. The known bio-orthogonality of copper-free click chemistry provides an opportunity to not only use it in vitro to create scaffolds or pro-migratory tracks in the presence of living cells, but also potentially apply it to living tissues directly as a coupling modality in situ. In this study, we studied the chemical coupling of growth factors to collagen using biocompatible copper-free click chemistry and its effect on the enhancement of growth factor activity in vitro. We verified the characteristics of modified epidermal growth factor (EGF) using mass spectrometry and an EGF/EGF receptor binding assay, and evaluated the chemical immobilization of EGF on collagen by copper-free click chemistry using surface X-ray photoelectron spectroscopy (XPS), surface plasmon resonance (SPR) spectroscopy, and enzyme-linked immunosorbent assay (ELISA). We found that the anchoring was noncytotoxic, biocompatible, and rapid. Moreover, the surface-immobilized EGF had significant effects on epithelial cell attachment and proliferation. Our results demonstrate the possibility of copper-free click chemistry as a tool for covalent bonding of growth factors to collagen in the presence of living cells. This approach is a novel and potentially clinically useful application of copper-free click chemistry as a way of anchoring growth factors to collagen and foster epithelial wound healing.

  1. Hybrid Al/steel-joints manufactured by ultrasound enhanced friction stir welding (USE-FSW): Process comparison, nondestructive testing and microscopic analysis

    Science.gov (United States)

    Thomä, M.; Wagner, G.; Straß, B.; Wolter, B.; Benfer, S.; Fürbeth, W.

    2017-03-01

    The process of friction stir welding (FSW) is an innovative joining technique, which proved its potential in joining dissimilar metals that are poorly fusion weldable. This ability opens a wide range for applications in industrial fields, where weight reduction by partial substitution of conventional materials through lightweight materials is a current central aim. As a consequence of this, the realization of aluminum / steel-joints is of great interest. For this material compound, several friction stir welds were carried out by different researchers for varying Al/steel-joints, whereas the definition of optimal process parameters as well as the increase of mechanical properties was in the focus of the studies. To achieve further improved properties for this dissimilar joint a newly developed hybrid process named “ultrasound enhanced friction stir welding (USE-FSW)” was applied. In this paper the resulting properties of Al/steel-joints using FSW and USE-FSW will be presented and compared. Furthermore, first results by using the nondestructive testing method “computer laminography” to analyze the developed joining area will be shown supplemented by detailed light-microscopic investigations, scanning electron microscopic analysis, and EDX.

  2. Caracterização microestrutural e propriedades mecânicas da liga de alumínio 2198-T851 em configuração tailored blank soldada por FSW - Friction Stir Welding

    Directory of Open Access Journals (Sweden)

    Ivan Moroz

    2012-03-01

    -based welding processes. Still, solid-state based joining processes are preferable because they avoid defects intrinsic to fusion, and have therefore been an object of study in the last couple of decades. The objective of this work was the characterization of a friction stir welded (FSW butt-joint of aluminum alloy 2198-T851 in tailored blanks configuration (sheets with different thicknesses. The methodology in which characterization was based involved the study of mechanical properties, through tensile tests and cross-section microhardness profiles determination, and the comprehension of the relation between microstructural changes caused by the welding process and resulting properties was sought. It was concluded that, due to metallurgical phenomena induced by the welding process, microstructural changes such as grain refinement, work-hardening and dissolution/formation of second phases as precipitates granted the attainment of a weld whose mechanical properties in tension (except elongation equaled or exceeded those of base material, showing the feasibility of using the FSW parameters considered in this work.

  3. Copper hypersensitivity

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  4. A Study on Some Copper(Ⅱ) Complexes of Polyaza Cryptandsand Planar Macrocycles-Synthesis, Characterization and Superoxide Dismutase Activity

    Institute of Scientific and Technical Information of China (English)

    GAO, You-Liang; SHEN, Cheng-Yu; TANG, Yin-Yan; LUO, Qin-Hui; YU, Shu-Yan

    2001-01-01

    Two kinds of macrocyclic copper(Ⅱ) complexes were synthesized. One of them is composed of copper(Ⅱ) cryptates of ligands L1-L4 which are condensation products of 5-R-2methoxy-1,3-phenyldialdehyde (R= OCH3, L1) with tris(2-aminoethyl)amine and 5-R-2-methothoxy-1, 3-phenyldialdehyde (R = CH3, L3) with tris(2-aminopropyi)amine as well as their reduced products of L1 and L3 (L2 and L4). The other is composed of two-dimensional macrocyclic copper(Ⅱ) complexcs of ligands L5-L8 of condensation products of diethylene triamine with 4-R-1-methoxy-2, 6-phenyldialdehyde (R = Cl,Br, CH3, OCH3). Therelationship between their structurcs and superoxide dismutase (SOD) activity was investigated.The results can provide some clues to the synthesis of SOD mimics.

  5. Fatigue properties for FSW and MIG welded joints of thickness plate aluminum alloy%厚板铝合金FSW和MIG焊接接头疲劳性能

    Institute of Scientific and Technical Information of China (English)

    杨新岐; 吴铁; 张家龙; 秦红珊

    2012-01-01

    对厚度10 mm的6082-T6铝合金搅拌摩擦焊(FSW)和MIG焊接接头的疲劳强度进行了试验研究,并与6082-T6母材疲劳性能进行了对比分析.结果表明,6082-T6母材的疲劳S-N曲线最高、MIG焊接接头S-N曲线度最低,而FSW接头的疲劳S-N曲线近似位于两者之间;在高应力区FSW疲劳强度低于MIG焊接接头、而在低应力区高于MIG焊接接头.大部分FSW试样疲劳裂纹启始于焊缝根部的"弱连接"缺陷,采用机械加工去掉1.4 mm厚度焊缝根部材料后,FSW疲劳强度明显提高并接近母材数据.厚板6082-T6铝合金FSW焊缝根部质量控制是影响疲劳性能的关键因素.%The fatigue properties of FSW and MIG welded joints for AA6082-T6 aluminum alloy of 10 mm thickness were investigated by the fatigue S-N curves testing method,and these prperties were also compared to that of AA6082-T6 base material.It was shown that the fatigue S-N curve of AA6082-T6 base material was the highest,the S-N curve of MIG welded joints was the lowest,and the S-N curve of FSW joint was between the two curves.In high stress range,the fatigue strength of FSW was lower than that of MIG welded joints,while in low stress range,it was higher than the MIG welded joints.It indicated that most of the FSW specimens were initially fractured at the weld,caused by the "weak-bonding" defects and the fatigue strength of FSW joint increased apparently,which is close to the values of base material after removing one layer of weld root material with thickness of 1.4 mm.Thus it can be verified that the quality of the weld root sites for the single-side FSW welded joints of AA6082-T6 aluminum alloys thick plate should be the key factor to influence the fatigue properties of FSW joint.

  6. Synthesis, characterization and fabrication of copper nanoparticles in N-isopropylacrylamide based co-polymer microgels for degradation of p-nitrophenol

    Directory of Open Access Journals (Sweden)

    Farooqi Zahoor H.

    2015-03-01

    Full Text Available Poly(N-isopropylacrylamide-co-acrylic acid [P(NIPAM-co-AAc] microgels were synthesized by precipitation polymerization. Copper nanoparticles were successfully fabricated inside the microgels by in-situ reduction of copper ions in an aqueous medium. The microgels were characterized by Fourier Transform Infrared Spectroscopy (FT-IR and Dynamic Light Scattering (DLS. Hydrodynamic radius of P(NIPAM-co-AAc microgel particles increased with an increase in pH in aqueous medium at 25 °C. Copper-poly(N-isopropylacrylamide-co-acrylic acid [Cu-P(NIPAM-co-AAc] hybrid microgels were used as a catalyst for the reduction of 4-nitrophenol (4-NP. Effect of temperature, concentration of sodium borohydride (NaBH4 and catalyst dosage on the value of apparent rate constant (kapp for catalytic reduction of 4-NP in the presence of Cu-P(NIPAM-co-AAc hybrid microgels were investigated by UV-Vis spectrophotometry. It was found that the value of kapp for catalytic reduction of 4-NP in the presence of Cu-P(NIPAM-co-AAc hybrid microgel catalyst increased with an increase in catalyst dosage, temperature and concentration of NaBH4 in aqueous medium. The results were discussed in terms of diffusion of reactants towards catalyst surface and swelling-deswelling of hybrid microgels.

  7. Iron(III and copper(II complexes bearing 8-quinolinol with amino-acids mixed ligands: Synthesis, characterization and antibacterial investigation

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    Saliu A. Amolegbe

    2015-09-01

    Full Text Available Four d-orbital metal complexes with mixed ligands derived from 8-hydroxyquinoline (HQ and amino acids (AA: l-alanine and methionine have been synthesized through a mild reflux in alkaline solution and characterized by elemental analyses, infrared, electronic transition, and temperature dependant magnetic susceptibility. The IR spectroscopy revealed that iron and copper ions coordinated through carbonyl (CO, hydroxyl group (OH of the amino acids, N-pyridine ring of hydroxyquinoline. The elemental analysis measurement with other obtained data suggested an octahedral geometry for the iron(III complexes and tetrahedral geometry for the copper(II complexes. From the molar magnetic susceptibility measurement, the iron(III system (S = 5/2 d5 (non-degenerate 6A1 with χmT = 0.38 cm3 Kmol−1 showed an antiferromagnetic while Cu2+ ions system (S = ½ (2T2g has χmT = 4.77 cm3 Kmol−1 described as paramagnetic behaviour. In vitro antimicrobial investigations of the metal complexes against standard bacteria species gave significant inhibition with, copper complex showing highest inhibitions against Pseudomonas aeruginosa (ATCC27853 of 43 mm at 10 μg/ml signalling its potential as pharmaceutical or chemotherapeutic agents.

  8. Cytotoxic activity, X-ray crystal structures and spectroscopic characterization of cobalt(II), copper(II) and zinc(II) coordination compounds with 2-substituted benzimidazoles.

    Science.gov (United States)

    Sánchez-Guadarrama, Obdulia; López-Sandoval, Horacio; Sánchez-Bartéz, Francisco; Gracia-Mora, Isabel; Höpfl, Herbert; Barba-Behrens, Noráh

    2009-09-01

    Herein we present the synthesis, structural and spectroscopic characterization of coordination compounds of cobalt(II), copper(II) and zinc(II) with 2-methylbenzimidazole (2mbz), 2-phenylbenzimidazole (2phbz), 2-chlorobenzimidazole (2cbz), 2-benzimidazolecarbamate (2cmbz) and 2-guanidinobenzimidazole (2gbz). Their cytotoxic activity was evaluated using human cancer cell lines, PC3 (prostate), MCF-7 (breast), HCT-15 (colon), HeLa (cervic-uterine), SKLU-1 (lung) and U373 (glioblastoma), showing that the zinc(II) and copper(II) compounds [Zn(2mbz)(2)Cl(2)].0.5H(2)O, [Zn(2cmbz)(2)Cl(2)].EtOH, [Cu(2cmbz)Br(2)].0.7H(2)O and [Cu(2gbz)Br(2)] had significant cytotoxic activity. The isostructural cobalt(II) complexes showed not significant activity. The cytotoxic activity is related to the presence of halides in the coordination sphere of the metal ion. Recuperation experiments with HeLa cells, showed that the cells recuperated after removing the copper(II) compounds and, on the contrary, the cells treated with the zinc(II) compounds did not. These results indicate that the mode of action of the coordination compounds is different.

  9. One step synthesis and characterization of copper doped sulfated titania and its enhanced photocatalytic activity in visible light by degradation of methyl orange

    Institute of Scientific and Technical Information of China (English)

    Radha Devi Chekuri; Siva Rao Tirukkovalluri

    2016-01-01

    This paper reports on the synthesis of copper doped sulfated titania nano-crystalline powders with varying (2.0%–10.0%, by mass) by single step sol gel method. The synthesized photo catalyst has been characterized by employing various techniques like X-ray Diffraction (XRD), Ultraviolet–Visible Diffuse Reflection Spectroscopy (UV–Vis DRS), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometry (EDS), Fourier Transform Infrared Spectroscopic Studies (FT-IR), and Transmission Electron Microscopy (TEM). From the XRD and TEM results, al the samples were reported in anatase phase with reduction in particle size in the range of 7 to 12 nm. SEM indicated the change in morphology of the particles. The presence of copper in titania lattice was evidenced by XPS. From UV–Vis DRS and FT-IR studies indicated that prominent absorption shift is observed towards visible region (red shift), the entry of Cu2+into TiO2 lattice as a substitution-al dopant and SO42− ions were covalently bonded with Ti4+ on the surface of the copper doped titania respectively. The photocatalytic activity studies were investigated by considering methyl orange (MO) as dye pol utant in the presence of the visible light. The effect of various parameters like effect of dosage of the catalyst, dopant concentration, pH of the solution, and concentration of the dye was studied in detail.

  10. Ternary complexes of copper(II) and cobalt(II) involving nitrite/pyrazole and tetradentate N4-coordinate ligand: Synthesis, characterization, structures and antimicrobial activity

    Science.gov (United States)

    Solanki, Ankita; Sadhu, Mehul H.; Kumar, Sujit Baran

    2015-12-01

    Five new mononuclear mixed ligand complexes of the type [Cu(NCCH3)(dbdmp)](ClO4)2, [M(ONO)(dbdmp)]ClO4, [M(pz) (dbdmp)](ClO4)2 where M = Cu(II) and Co(II), pz = 3,5-dimethylpyrazole and dbdmp = N,N-diethyl-N‧,N‧-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)ethane-1,2-diamine have been synthesized and characterized by physico-chemical and spectroscopy studies. The crystal structures of three copper(II) complexes [Cu(NCCH3)(dbdmp)](ClO4)2, [Cu(ONO)(dbdmp)]ClO4 and [Cu(pz)(dbdmp)](ClO4)2 have been determined by single crystal X-ray diffraction studies. Structural analyses reveal the geometry of [Cu(pz)(dbdmp)](ClO4)2 is distorted square pyramidal and other two copper(II) complexes have distorted trigonal bipyramidal geometry. Molecular composition of cobalt(II) complexes have been determined by mass spectral data. The EPR spectra of copper(II) complexes in frozen acetonitrile solution exhibit axial spectra, characteristic of dx2-y2 ground state. Electrochemical studies of copper(II) complexes using glassy carbon as working electrode in acetonitrile solution show Cu(II)/Cu(I) couple with quasi reversible electron transfer versus Ag/Ag+ reference electrode. Antimicrobial activity of all the synthesized complexes were investigated against two Gram positive and two Gram negative bacterial strains.

  11. Synthesis, characterization and biological activities of copper(II) complex of 2-Benzimidazolyl-urea and the nitrate salt of 2-Benzimidazolyl-urea

    Science.gov (United States)

    Poyraz, Mehmet; Sari, Musa; Banti, Christina N.; Hadjikakou, Sotiris K.

    2017-10-01

    The synthesis of the complex {[Cu(BZIMU)2](NO3)2} (1) (BZIMU = 2-Benzimidazolyl-urea) is reported here. The complex 1 was characterized by elemental analysis, FT-IR, magnetic susceptibility and molar conductance measurements. The crystal structures of 1 and of the nitrate salt of [(BZIMUH+)(NO3)-] (2) were determined by X-ray diffraction analysis. The copper complex 1 and [(BZIMUH+)(NO3)-] (2) were evaluated for their in vitro cytotoxic activity (cell viability) against human cervix adenocarcinoma (HeLa) and human breast adenocarcinoma (MCF-7) cell line and normal human fetal lung fibroblast cells (MRC-5) with SRB assay.

  12. Syntheses, characterization, crystal structure and manetic properties of copper(Ⅱ) a, b-unsaturated carboxylate complexes with trimethyl phosphate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Two ternary complexes Cu2A4[OP(OCH3)3]2 (A represents CH2== CH-COO- and CH2==C(CH3)-COO-) have been synthesized, and elemental analyses, IR, ESR, electronic reflectance spectra and magnetic studies were carried out. The single crystal X-ray diffraction shows that Cu2[CH2== C(CH3)-COO]4[OP(OCH3)3]2 is triclinic, with space group P, a = 1.05128(13), b = 1.7559(5), c = 1.94479(3) nm, α = 91.263(14)°, β = 102.559(6)°, γ = 106.339(13)°, Z = 4 and R = 0.0668. Two copper(Ⅱ) atoms are bridged by four a-methacrylate groups, and each copper(Ⅱ) atom is coordi-nated with a trimethyl phosphate molecule in the axial posi-tion, forming a distorted square pyramidal configuration. The symmetric center is between the two copper(Ⅱ) atoms, and the Cu-Cu bond distance is 0.26098(6) nm. The Cu-Cu distance and magnetic studies suggest that there exist an-tiferromagnetic interactions between the two copper(Ⅱ) atoms.

  13. Identification and characterization of microRNAs from tree peony (Paeonia ostii) and their response to copper stress.

    Science.gov (United States)

    Jin, Qijiang; Xue, Zeyun; Dong, Chunlan; Wang, Yanjie; Chu, Lingling; Xu, Yingchun

    2015-01-01

    MicroRNAs (miRNAs) are a class of non-coding, small RNAs recognized as important regulators of gene expression. Although plant miRNAs have been extensively studied in model systems, less is known in other plants with limited genome sequence data, including Paeonia ostii. In this work, we used high-throughput sequencing to identify conserved and nonconserved miRNAs and other short RNAs in Paeonia ostii under control and copper stressed condition. 102 previously known plant miRNAs were identified and classified into 89 families according to their gene sequence identity. Some miRNAs were highly conserved in the plant kingdom suggesting that these miRNA play important and conserved roles. Combined our transcriptome sequencing data of Paeonia ostii under same conditions, 34 novel potential miRNAs were identified. The potential targets of the identified known and novel miRNAs were also predicted based on sequence homology search. Comparing the two libraries, it was observed that 12 conserved miRNAs and 18 novel miRNAs showed significantly changes in response to copper stress. Some of the new identified potential miRNAs might be involved in Paeonia ostii-specific regulating mechanisms under copper stress. These results provide a framework for further analysis of miRNAs and their role in regulating Paeonia ostii response to copper stress.

  14. Identification and characterization of microRNAs from tree peony (Paeonia ostii and their response to copper stress.

    Directory of Open Access Journals (Sweden)

    Qijiang Jin

    Full Text Available MicroRNAs (miRNAs are a class of non-coding, small RNAs recognized as important regulators of gene expression. Although plant miRNAs have been extensively studied in model systems, less is known in other plants with limited genome sequence data, including Paeonia ostii. In this work, we used high-throughput sequencing to identify conserved and nonconserved miRNAs and other short RNAs in Paeonia ostii under control and copper stressed condition. 102 previously known plant miRNAs were identified and classified into 89 families according to their gene sequence identity. Some miRNAs were highly conserved in the plant kingdom suggesting that these miRNA play important and conserved roles. Combined our transcriptome sequencing data of Paeonia ostii under same conditions, 34 novel potential miRNAs were identified. The potential targets of the identified known and novel miRNAs were also predicted based on sequence homology search. Comparing the two libraries, it was observed that 12 conserved miRNAs and 18 novel miRNAs showed significantly changes in response to copper stress. Some of the new identified potential miRNAs might be involved in Paeonia ostii-specific regulating mechanisms under copper stress. These results provide a framework for further analysis of miRNAs and their role in regulating Paeonia ostii response to copper stress.

  15. A novel Schiff base derived from the gabapentin drug and copper (II) complex: Synthesis, characterization, interaction with DNA/protein and cytotoxic activity.

    Science.gov (United States)

    Shokohi-Pour, Zahra; Chiniforoshan, Hossein; Momtazi-Borojeni, Amir Abbas; Notash, Behrouz

    2016-09-01

    A novel Schiff base [C20H23NO3], has been prepared and characterized using FT-IR, UV-vis, (1)H NMR spectroscopy, elemental analysis and X-ray crystallography. A copper (II) complex [Cu(C20H22NO3)2]·H2O has also been synthesized and characterized. The new ligand and complex thus obtained were investigated by their interaction with calf thymus DNA and BSA using electronic absorption spectroscopy, fluorescence spectroscopy, and thermal denaturation. The intrinsic binding constants Kb of the ligand and Cu (II) complex, with CT-DNA obtained from UV-vis absorption studies were 1.53×10(4)M(-1) and 3.71×10(5)M(-1), respectively. Moreover the addition of the two compounds to CT-DNA (1:2) led to an increase of the melting temperature of DNA up to around 2.61°C for the ligand and 3.99°C for the Cu (II) complex. The ligand and Cu (II) complex bind to CT-DNA via a partial intercalative, as shown by the experimental data. In addition, the albumin interactions of the two compounds were studied by fluorescence quenching spectra, the results indicating that the binding mechanism is a static quenching process. The in vitro cytotoxicity of the two compounds on three different cancer cell lines was evaluated by MTT assay. The results showed that the copper complex exerted enhanced cytotoxicity compared with the Schiff base ligand; thereby, this complex clearly implies a positive synergistic effect. Furthermore, the copper complex showed a high, selective, and dose-dependent cytotoxicity against cancer cell lines.

  16. Operationally defined species characterization and bioaccessibility evaluation of cobalt, copper and selenium in Cape gooseberry (Physalis Peruviana L.) by SEC-ICP MS.

    Science.gov (United States)

    Wojcieszek, Justyna; Ruzik, Lena

    2016-03-01

    Physalis peruviana could attract great interest because of its nutritional and industrial properties. It is an excellent source of vitamins, minerals, essential fatty acids and carotenoids. Physalis Peruviana is also known to have a positive impact on human health. Unfortunately, still little is known about trace elements present in Physalis Peruviana and their forms available for the human body. Thus, the aim of this study was to estimate bioaccessibility and characterization of species of cobalt, copper and selenium in Physalis Peruviana fruits. Total and extractable contents of elements were determined by mass spectrometer with inductively coupled plasma (ICP MS). In order to separate the different types of metal complexes Physalis peruviana fruits were treated with the following solvents: Tris-HCl (pH 7.4), sodium dodecyl sulfate (SDS) (pH 7.4) and ammonium acetate (pH 5.5). The best efficiency of extraction of: cobalt was obtained for ammonium acetate (56%) and Tris-HCl (60%); for copper was obtained for SDS (66%), for selenium the best extraction efficiency was obtained after extraction with SDS (48%). To obtain information about bioaccessibility of investigated elements, enzymatic extraction based on in vitro simulation of gastric (pepsin) and intestinal (pancreatin) digestion was performed. For copper and selenium the simulation of gastric digestion leads to the extraction yield above 90%, while both steps of digestion method were necessary to obtain satisfactory extraction yield in the case of cobalt. Size exclusion chromatography (SEC) coupled to on-line ICP MS detection was used to investigate collected metal species. The main fraction of metal compounds was found in the 17 kDa region. Cobalt and copper create complexes mostly with compounds extracted by means of ammonium acetate and SDS, respectively. Cobalt, copper and selenium were found to be highly bioaccessible from Physalis Peruviana. Investigation of available standards of cobalt and selenium

  17. Synthesis, Characterization, and Biological Studies of Binuclear Copper(II Complexes of (2E-2-(2-Hydroxy-3-Methoxybenzylidene-4N-Substituted Hydrazinecarbothioamides

    Directory of Open Access Journals (Sweden)

    P. Murali Krishna

    2013-01-01

    Full Text Available Four novel binuclear copper(II complexes [1–4] of (2E-2-(2-hydroxy-3-methoxybenzylidene-4N-substituted hydrazinecarbothioamides, (OH(OCH3C6H4CH=NNHC(SNHR, where R = H (L1, Me (L2, Et (L3, or Ph (L4, have been synthesized and characterized. The FT-IR spectral data suggested the attachment of copper(II ion to ligand moiety through the azomethine nitrogen, thioketonic sulphur, and phenolic-O. The spectroscopic characterization indicates the dissociation of dimeric complex into mononuclear [Cu(LCl] units in polar solvents like DMSO, where L is monoanionic thiosemicarbazone. The DNA binding properties of the complexes with calf thymus (CT DNA were studied by spectroscopic titration. The complexes show binding affinity to CT DNA with binding constant (Kb values in the order of 106 M−1. The ligands and their metal complexes were tested for antibacterial and antifungal activities by agar disc diffusion method. Except for complex 4, all complexes showed considerable activity almost equal to the activity of ciprofloxacin. These complexes did not show any effect on Gram-negative bacteria, whereas they showed moderate activity for Gram-positive strains.

  18. Syntheses and structural characterization of iron(II) and copper(II) coordination compounds with the neutral flexible bidentate N-donor ligands

    Science.gov (United States)

    Beheshti, Azizolla; Lalegani, Arash; Bruno, Giuseppe; Rudbari, Hadi Amiri

    2014-08-01

    Two new coordination compounds [Fe(bib)2(N3)2]n(1) and [Cu2(bpp)2(N3)4] (2) with azide and flexible ligands 1,4-bis(imidazolyl)butane (bib) and 1,3-bis(3,5-dimethylpyrazolyl)propane (bpp) were prepared and structurally characterized. In the 2D network structure of 1, the iron(II) ion lies on an inversion center and exhibits an FeN6 octahedral arrangement while in the dinuclear structure of 2, the copper(II) ion adopts an FeN5 distorted square pyramid geometry. In the complex 1, each μ2-bib acts as bridging ligand connecting two adjacent iron(II) ions while in the complex 2, the bpp ligand is coordinated to copper(II) ion in a cyclic-bidentate fashion forming an eight-membered metallocyclic ring. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction. Thermal analysis of polymer 1 was also studied.

  19. Abriendo Puertas: baseline findings from an integrated intervention to promote prevention, treatment and care among FSW living with HIV in the Dominican Republic.

    Directory of Open Access Journals (Sweden)

    Yeycy Donastorg

    Full Text Available Female sex workers (FSW are often the focus of primary HIV prevention efforts. However, little attention has been paid to the prevention, treatment, and care needs of FSW living with HIV. Based on formative research, we developed an integrated model to promote prevention and care for FSW living with HIV in Santo Domingo, Dominican Republic, including (1 individual counseling and education; (2 peer navigation; (3 clinical provider training; and (4 community mobilization. We enrolled 268 FSW living with HIV into the intervention and conducted socio-behavioral surveys, sexually transmitted infection (STI testing, and viral load (VL assessments. We used multivariate logistic regression to identify behavioral and socio-demographic factors associated with detectable VL (>50 copies/mL and STI prevalence. Over half of all participants (51.9% had a detectable VL, even though most received HIV-related care in the last 6 months (85.1% and were currently on anti-retroviral treatment (ART (72.4%. Factors positively associated with a detectable VL included being 18-35 years of age (Adjusted Odds Ratio [AOR] 2.46, 95% CI 1.31-4.60, having ever used drugs (AOR 2.34, 95% CI 1.14-4.79, and having ever interrupted ART (AOR 3.09, 95% CI 1.44-6.59. Factors protective against having a detectable VL included being single (AOR 0.45, 95% 0.20-0.98 and being currently on ART (AOR 0.17, 95% CI 0.07-0.41. Nearly one-quarter (23.1% had an STI, which was associated with being single (AOR 3.21, 95% CI 1.27-8.11 and using drugs in the last 6 months (AOR 3.54, 95% CI 1.32-9.45. Being on ART was protective against STI (AOR 0.51, 95% CI 0.26-1.00. Baseline findings indicate significant barriers to VL suppression and STI prevention among FSW living with HIV and highlight gaps in the continuum of HIV care and treatment. These findings have important implications for both the individual health of FSW and population-level HIV transmission dynamics.

  20. Preparation, characterization, and condensation of copper tellurolate clusters in the pores of periodic mesoporous silica MCM-41.

    Science.gov (United States)

    Kowalchuk, Collin M; Schmid, Günter; Meyer-Zaika, Wolfgang; Huang, Yining; Corrigan, John F

    2004-01-12

    The copper-tellurolate cluster [(Cu(6)(TePh)(6)(PPh(2)Et)(5)] has been loaded into the pores of MCM-41 by solid-state impregnation techniques. It was found that the best loading conditions are 110 degrees C and 10(-)(3) Torr static vacuum. The resulting material was analyzed by powder X-ray diffraction (PXRD), nitrogen adsorption isotherms, thermogravimetric analysis (TGA), (31)P CP MAS NMR spectroscopy, and TEM. It was observed that loading is accompanied by loss of the phosphine shell, with retention of the copper-tellurium core. Condensation of the impregnated material may proceed thermally or photochemically. Thermal condensation results in the formation of Cu(2)Te nanoparticles as demonstrated by PXRD, and TEM data suggests that the process has taken place inside the pores of MCM-41. Photochemical condensation yields larger metal-chalcogen clusters in the pores as suggested by the result of UV-vis diffuse reflectance spectroscopy and TEM measurements.

  1. SBA-15 mesoporous silica free-standing thin films containing copper ions bounded via propyl phosphonate units - preparation and characterization

    Science.gov (United States)

    Laskowski, Lukasz; Laskowska, Magdalena; Jelonkiewicz, Jerzy; Dulski, Mateusz; Wojtyniak, Marcin; Fitta, Magdalena; Balanda, Maria

    2016-09-01

    The SBA-15 silica thin films containing copper ions anchored inside channels via propyl phosphonate groups are investigated. Such materials were prepared in the form of thin films, with hexagonally arranged pores, laying rectilinear to the substrate surface. However, in the case of our thin films, their free standing form allowed for additional research possibilities, that are not obtainable for typical thin films on a substrate. The structural properties of the samples were investigated by X-ray reflectometry, atomic force microscopy (AFM) and transmission electron microscopy (TEM). The molecular structure was examined by Raman spectroscopy supported by numerical simulations. Magnetic measurements (SQUID magnetometry and EPR spectroscopy) showed weak antiferromagnetic interactions between active units inside silica channels. Consequently, the pores arrangement was determined and the process of copper ions anchoring by propyl phosphonate groups was verified in unambiguous way. Moreover, the type of interactions between magnetic atoms was determined.

  2. Characterization of Copper Coatings Deposited by High-Velocity Oxy-Fuel Spray for Thermal and Electrical Conductivity Applications

    Science.gov (United States)

    Salimijazi, H. R.; Aghaee, M.; Salehi, M.; Garcia, E.

    2017-08-01

    Copper coatings were deposited on steel substrates by high-velocity oxy-fuel spraying. The microstructure of the feedstock copper powders and free-standing coatings were evaluated by optical and scanning electron microscopy. The x-ray diffraction pattern was utilized to determine phase compositions of powders and coatings. Oxygen content was determined by a LECO-T300 oxygen determiner. The thermal conductivity of the coatings was measured in two directions, through-thickness and in-plane by laser flash apparatus. The electrical resistivity of the coatings was measured by the four-point probe method. Oxygen content of the coatings was two times higher than that of the initial powders (0.35-0.37%). The thermal and electrical conductivities of the coatings were different depending on the direction of the measurement. The thermal and electrical conductivity of the coatings improved after annealing for 6 h at a temperature of 600°C.

  3. Factors associated with history of drug use among female sex workers (FSW in a high HIV prevalence state of India

    Directory of Open Access Journals (Sweden)

    Medhi Gajendra

    2012-04-01

    Full Text Available Abstract Background The intersection between illicit drug use and female commercial sex work has been identified as an important factor responsible for rising HIV prevalence among female sex workers (FSW in several northeastern states of India. But, little is know about the factors associated with the use of drugs among FSWs in this region. The objective of the paper was to describe the factors associated with history of drug use among FSWs in Dimapur, an important commercial hub of Nagaland, which is a high HIV prevalence state of India. Methods FSWs were recruited using respondent driven sampling (RDS, and were interviewed to collect data on socio-demographic characteristics and HIV risk behaviours. Biological samples were tested for HIV, syphilis gonorrhea and Chlamydia. Logistic regression analysis was performed to identify factors associated with drug use. Results Among the 426 FSWs in the study, about 25% (n = 107 reported having ever used illicit drugs. Among 107 illicit drug users, 83 (77.6% were non-injecting and 24 (22.4% were injecting drug users. Drug-using FSWs were significantly more likely to test positive for one or more STIs (59% vs. 33.5%, active syphilis (27.1% vs. 11.4% and Chlamydia infection (30% vs. 19.9% compared to their non-drug using peers. Drug-using FSWs were also significantly more likely to be currently married, widowed or separated compared with non-drug-using FSWs. In multiple logistic regression analysis, being an alcohol user, being married, having a larger volume of clients, and having sexual partners who have ever used or shared injecting drugs were found to be independently associated with illicit drug use. Conclusions Drug-using FSWs were more vulnerable to STIs including HIV compared to their non-drug using peers. Several important factors associated with being an FSW who uses drugs were identified in this study and this knowledge can be used to plan more effectively targeted harm reduction strategies

  4. Fate and transport with material response characterization of green sorption media for copper removal via adsorption process.

    Science.gov (United States)

    Chang, Ni-Bin; Houmann, Cameron; Lin, Kuen-Song; Wanielista, Martin

    2016-02-01

    Green adsorption media with the inclusion of renewable and recycled materials can be applied as a stormwater best management practice for copper removal. A green adsorption media mixture composed of recycled tire chunk, expanded clay aggregate, and coconut coir was physicochemically evaluated for its potential use in an upflow media filter. A suite of tests were conducted on the media mixture and the individual media components including studies of particle size distribution, isotherms, column adsorption and reaction kinetics. Isotherm test results revealed that the coconut coir had the highest affinity for copper (q(max) = 71.1 mg g(-1)), and that adsorption was maximized at a pH of 7.0. The coconut coir also performed the best under dynamic conditions, having an equilibrium uptake of 1.63 mg g(-1). FE-SEM imaging found a strong correlation between the porosity of the micro pore structure and the adsorptive capacity. The use of the green adsorption media mixture in isolation or the coconut coir with an expanded clay filtration chamber could be an effective and reliable stormwater best management practice for copper removal. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ping Wu; Lingvall, F.; Stepinski, T. [Uppsala Univ. (Sweden). Dept. of Material Science

    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

  6. Characterization of ACC deaminase-producing endophytic bacteria isolated from copper-tolerant plants and their potential in promoting the growth and copper accumulation of Brassica napus.

    Science.gov (United States)

    Zhang, Yan-Feng; He, Lin-Yan; Chen, Zhao-Jin; Wang, Qing-Ya; Qian, Meng; Sheng, Xia-Fang

    2011-03-01

    One hundred Cu-resistant-endophytic bacteria were isolated from Cu-tolerant plants grown on Cu mine wasteland, of which, eight Cu-resistant and 1-aminocyclopropane-1-carboxylate (ACC) deaminase-producing endophytic bacteria were obtained based on the ACC deaminase activity of the bacteria and characterized with respect to metal resistance, production of ACC deaminase, indole-3-acetic acid (IAA) as well as siderophores and mineral phosphate solubilization. Ralstonia sp. J1-22-2, Pantoea agglomerans Jp3-3, and Pseudomonas thivervalensis Y1-3-9 with higher ACC deaminase activity (ranging from 213 to 370 μM α-ketobutyrate mg(-1)h(-1)) were evaluated for promoting plant growth and Cu uptake of rape grown in quartz sand containing 0, 2.5, and 5 mg kg(-1) of Cu in pot experiments. The eight bacteria were found to exhibit different multiple heavy metal resistance characteristics, to show different levels of ACC deaminase activity and to produce indole acetic acid. Seven bacteria produced siderophores and solubilized inorganic phosphate. Pot experiments showed that inoculation with the strains (J1-22-2, Jp3-3, and Y1-3-9) was found to increase the biomass of rape. Increases in above-ground tissue Cu contents of rape cultivated in 2.5 and 5 mg kg(-1) of Cu-contaminated substrates varied from 9% to 31% and from 3 to 4-fold respectively in inoculated-rape plants compared to the uninoculated control. The maximum Cu uptake of rape was observed after inoculation with P. agglomerans Jp3-3. The results show that metal-resistant and plant growth promoting endophytic bacteria play an important role in plant growth and Cu uptake which may provide a new endophytic bacterial-assisted phytoremediation of Cu-contaminated environment.

  7. Characterization of fluid inclusions and sulfur isotopes in the Iju porphyry copper deposit, North West of Shahr-e-Babak

    Directory of Open Access Journals (Sweden)

    Malihe Golestani

    2017-07-01

    Full Text Available Introduction The Iju porphyry copper deposit is located in the southern part of the Urumieh-Dokhtar magmatic arc (Dehaj-Sarduieh belt within the Kerman copper belt (Dimitrijevic, 1973. The Porphyry Copper mineralization in the Iranian plate occurs dominantly along the Urumieh-Dokhtar arc, which has resulted from the subduction of the Arabian plate beneath the central Iran and the closure of the Neo-Tethys Ocean during the Alpine orogeny (Hassanzadeh, 1993. The Iju porphyry copper deposit with 25 million tons of ore reserves is one of the main copper deposits within the Kerman copper belt. The mining area is composed of upper Miocene volcanic and subvolcanic rocks (mineralized and barren subvolcanic rocks and quaternary deposits. Two hydrothermal alteration zones of quartz-sericite-pyrite and propylitic zones can be identified in the Iju area. The copper mineralization in the Iju deposit occurs as disseminated, stockwork and hydrothermal breccia. In the hypogene zone, the mineral paragenesis include chalcopyrite, pyrite, with minor occurrences of bornite and magnetite. This paper reports geological, mineralogical, fluid inclusion and S isotope data from the Iju deposit in order to investigate ore-bearing fluids’ characteristics and the mechanisms of ore deposition. Materials and methods Fifteen samples of syngenetic quartz+pyrite bearing veinlets within the quartz-sericite-pyrite zone were selected from different depths across the seven boreholes. Quartz was used for double-polished thin sections and pyrite was used for sulfur isotope analysis. Fluid inclusion studies were performed using the Linkam cooling and heating stage, the THMSG 600 model. The syngenetic pyrite with thermometry quartz sample was used for the sulfur isotope experiments. Stable isotope analysis was performed at the Hatch Stable Isotope Laboratory in the University of Ottawa, Canada. Results The fluid inclusions of the Iju deposit represent a wide range in the

  8. Synthesis and characterization of mononuclear copper(II) complexes of pyridine 2-carboxamide: Their application as catalyst in peroxidative oxidation and antimicrobial agents

    Indian Academy of Sciences (India)

    Suvendu Samanta; Shounak Ray; Sutapa Joardar; Supriya Dutta

    2015-08-01

    Four water soluble copper(II) complexes, [Cu(HL)2 (H2O)2]Cl2 (1), [Cu(HL) 2 (ClO4)2 ] (2), [Cu(HL)2 (SCN)2] (3) and [CuL 2 ]·8H 2 O (4), where HL is pyridine 2–carboxamide, have been synthesized and characterized by various spectroscopic techniques. Structures have been determined by single crystal X-ray crystallography. The pH induced inter-conversion of Cu(HL)2 (H2O)2 ]Cl2 (1) and [CuL2]·8H2O (4) through co-ordination mode switching was investigated thoroughly with the help of absorption spectroscopy. Complexes 1–3 were found to be active catalysts for the oxidation of toluene, ethyl benzene and cyclohexane in the presence of hydrogen peroxide as the oxidant under mild conditions. Toluene was oxidized to benzyl alcohol and benzaldehyde, ethyl benzene was oxidized to 1-phenylethanol and acetophenone and cyclohexane was oxidized to yield cyclohexanol and cyclohexanone Antimicrobial activities have been investigated with these copper(II) complexes against gram + ve bacteria, gram − ve bacterial and fungal species.

  9. A new tetranuclear copper(I) complex based on allyl(5-phenyl-1,3,4-thiadiazol-2-yl)azanide ligand: Synthesis and structural characterization

    Science.gov (United States)

    Slyvka, Yu. I.; Goreshnik, E. A.; Ardan, B. R.; Veryasov, G.; Morozov, D.; Mys'kiv, M. G.

    2015-04-01

    By means of alternating current electrochemical technique a new tetranuclear crystalline copper(I) complex [CuI4(L-)4] (L- - allyl(5-phenyl-1,3,4-thiadiazol-2-yl)azanide ion) has been obtained and characterized by X-ray single crystal diffraction (Sp.gr. I41/a) and Raman spectroscopy. The metal center adopts linear arrangement, composed of one thiadiazole N atom from the one L- anion and one azanide N atom of the other L- ligand. A bridged Cu atoms stitch four L- ligands into the firstly observed tetranuclear copper(I) azanide complex with intramolecular Cu(I)⋯Cu(I) interactions at the distance of 2.7451(6) Å. Molecular structure and Raman spectrum of the compound have been computed using the DFT B3LYP methodology and the cc-pVDZ basis set. The results are compared with the experimental data obtained. Spectrum calculation followed by normalization to the most intensive peak allowed providing detailed vibrational band assignment.

  10. Synthesis, characterization and catechol oxidase biomimetic catalytic activity of cobalt(II and copper(II complexes containing N2O2 donor sets of imine ligands

    Directory of Open Access Journals (Sweden)

    Mohamed I. Ayad

    2016-11-01

    Full Text Available New tetradentate imine ligands are derived from Schiff base condensation in a 1:2 molar ratio of the 1,2,4,5-tetra-amino benzene with 2-hydroxy benzaldehyde, (L1, 2,4-dihydroxy benzaldehyde (L2 and 2-hydroxy naphthaldehyde (L3. These ligands react with CoCl2 and CuCl2 in refluxing ethanol to yield a series of cobalt(II and copper(II complexes of the type [M2IILn] nH2O. The structure of the obtained ligands and their metal(II complexes were characterized by various physicochemical techniques, viz. elemental analysis, molar conductance, magnetic susceptibility measurements, thermal analysis (TGA & DTG, IR, electronic absorption and ESR spectral studies. Four-coordinate tetrahedral and square–planar structures were proposed for cobalt(II and copper(II complex species respectively. The ability of the synthesized complexes to catalyze the aerobic oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC to the light absorbing 3,5-di-tert-butylquinone (3,5-DTBQ has been investigated. The results obtained show that all complexes catalyze this oxidation reaction and slight variations in the rate were observed. The probable mechanistic implications of the catalytic oxidation reactions are discussed.

  11. Electrodeposition, characterization and long term stability of NiW and NiWZn coatings on copper substrate in alkaline solution

    Science.gov (United States)

    Sürme, Yavuz; Gürten, A. Ali; Kayakırılmaz, Kadriye

    2013-07-01

    This paper describes the electrodeposition of Ni, NiW and NiWZn coatings onto copper surfaces from electrolyte solutions containing Na3C6H5O7, Na2WO4, NiSO4 and ZnSO4. The electrocatalytic effects of electrodeposited coatings were investigated for hydrogen evolution reactions in 1 M NaOH solution. Surface characterization studies were carried out by energy dispersive X-ray spectroscopy, scanning electron microscopy, atomic force microscopy and cross-section analysis. The effect of operating conditions on the chemical composition, microstructure and electrocatalytic properties of Ni-W coatings was studied. The Zn ions were used to improve the active surface area and catalytic activity of the electrodeposited surface. The electrocatalytic activity of NiW and NiWZn coated electrodes for the hydrogen evolution reaction in alkaline solution was compared with that of an electrodeposited Ni electrode and copper substrate by using cathodic polarization curves and electrochemical impedance spectroscopy techniques over 96 h of electrolysis. The results proved that the NiWZn coated electrode showed better electrocatalytic activity and durability than bare Cu, Ni and NiW coatings.

  12. Synthesis, characterization and antibacterial activity of copper, nickel and bimetallic Cu–Ni nanoparticles for potential use in dental materials

    Directory of Open Access Journals (Sweden)

    Liliana Argueta-Figueroa

    2014-08-01

    Full Text Available The antibacterial effect is a desirable property in dental materials. Development of simple methods for the preparation of nanosized metal particles has attracted significant attention because of their future applications due to unusual size-dependent antibacterial properties. Copper (Cu, Nickel (Ni and bimetallic Cu–Ni nanoparticles were prepared by a simple chemical method and their antibacterial activity was tested against the widely used standard human pathogens Staphylococcus aureus (gram-negative and Escherichia coli (gram-positive. Additionally, these nanoparticles were tested against the dental pathogen Streptococcus mutans. Our results are promising for potential use in dental materials science.

  13. Synthesis, characterization and antibacterial activity of copper, nickel and bimetallic Cu-Ni nanoparticles for potential use in dental materials

    Institute of Scientific and Technical Information of China (English)

    Liliana Argueta-Figueroa; Raúl A. Morales-Luckie; Rogelio J. Scougall-Vilchis; Oscar F. Olea-Mejía

    2014-01-01

    The antibacterial effect is a desirable property in dental materials. Development of simple methods for the preparation of nanosized metal particles has attracted significant attention because of their future applications due to unusual size-dependent antibacterial properties. Copper (Cu), Nickel (Ni) and bimetallic Cu-Ni nanoparticles were prepared by a simple chemical method and their antibacterial activity was tested against the widely used standard human pathogens Staphylococcus aureus (gram-negative) and Escherichia coli (gram-positive). Additionally, these nanoparticles were tested against the dental pathogen Streptococcus mutans. Our results are promising for potential use in dental materials science.

  14. 铜基氧化物气凝胶的制备与表征%Synthesis and characterization of copper-based aerogels

    Institute of Scientific and Technical Information of China (English)

    毕于铁; 任洪波; 杨静; 黄燕; 张林

    2011-01-01

    以CuCl2·2H2O为前躯体,环氧丙烷为凝胶促进剂,制得了铜基氧化物气凝胶.通过场发射扫描电镜、高分辨透射电镜、X射线衍射、红外谱图及N2吸附等方法,对气凝胶的结构进行了表征.结果表明:室温下合成的铜基氧化物气凝胶呈现3维网络状结构,其骨架由大量微小晶粒组成,颗粒粒径为几nm;随处理温度的升高,体系中的有机相逐渐被灼烧完全,气凝胶也由3维网络状结构转变为致密结构;气凝胶随温度升高不断变化,并最终生成氧化铜气凝胶.N2吸附结果表明气凝胶具有较高的比表面积,为386m2/g.%Copper-based aerogels were prepared by sol-gel method using inorganic salt as precursor and propylene oxide as gelation agent. The morphology of the copper-based aerogels was characterized by field-emission scanning electron microscope (FESEM) and high-resolution transmission electron microscopy (HRTEM) , which suggests that the aerogels have a structure of 3-D networks and the skeleton is composed of CuO particles. The X-ray diffraction(XRD) results indicate that, the calcination of the aerogels at higher temperatures induces a phase change which results in the formation of copper oxide aerogels. The N2 adsorption/desorption result shows that the copper-based aerogels have a high specific surface area of about 386 m2 /g.

  15. Fate and transport with material response characterization of green sorption media for copper removal via desorption process.

    Science.gov (United States)

    Chang, Ni-Bin; Houmann, Cameron; Lin, Kuen-Song; Wanielista, Martin

    2016-07-01

    Multiple adsorption and desorption cycles are required to achieve the reliable operation of copper removal and recovery. A green sorption media mixture composed of recycled tire chunk, expanded clay aggregate, and coconut coir was evaluated in this study for its desorptive characteristics as a companion study of the corresponding adsorption process in an earlier publication. We conducted a screening of potential desorbing agents, batch desorption equilibrium and kinetic studies, and batch tests through 3 adsorption/desorption cycles. The desorbing agent screening revealed that hydrochloric acid has good potential for copper desorption. Equilibrium data fit the Freundlich isotherm, whereas kinetic data had high correlation with the Lagergren pseudo second-order model and revealed a rapid desorption reaction. Batch equilibrium data over 3 adsorption/desorption cycles showed that the coconut coir and media mixture were the most resilient, demonstrating they could be used through 3 or more adsorption/desorption cycles. FE-SEM imaging, XRD, and EDS analyses supported the batch adsorption and desorption results showing significant surface sorption of CuO species in the media mixture and coconut coir, followed by partial desorption using 0.1 M HCl as a desorbing agent. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Acid-base characterization, coordination properties towards copper(II) ions and DNA interaction studies of ribavirin, an antiviral drug.

    Science.gov (United States)

    Nagaj, Justyna; Starosta, Radosław; Jeżowska-Bojczuk, Małgorzata

    2015-01-01

    We have studied processes of copper(II) ion binding by ribavirin, an antiviral agent used in treating hepatitis C, which is accompanied usually by an increased copper level in the serum and liver tissue. Protonation equilibria and Cu(II) binding were investigated using the UV-visible, EPR and NMR spectroscopic techniques as well as the DFT (density functional theory) calculations. The spectroscopic data suggest that the first complex is formed in the water solution at pH as low as 0.5. In this compound Cu(II) ion is bound to one of the nitrogen atoms from the triazole ring. Above pH6.0, the metal ion is surrounded by two nitrogen and two oxygen atoms from two ligand molecules. The DFT calculations allowed to determine the exact structure of this complex. We found that in the lowest energy isomer two molecules of the ligand coordinate via O and N4 atoms in trans positions. The hypothetical oxidative properties of the investigated system were also examined. It proved not to generate plasmid DNA scission products. However, the calf thymus (CT)-DNA binding studies showed that it reacts with ribavirin and its cupric complex. Moreover, the interaction with the complex is much more efficient.

  17. Audiomagnetotelluric data to characterize the Revett-type copper-silver deposits at Rock Creek in the Cabinet Mountains Wilderness, Montana

    Science.gov (United States)

    Sampson, Jay A.; Rodriguez, Brian D.

    2011-01-01

    The Revett-type deposits at Rock Creek are part of the concealed stratabound copper-silver deposits located in the Cabinet Mountains Wilderness of Montana. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. Geologic, geochemical, geophysical, and mineral resources data are being evaluated with existing and new mineral deposit models to predict the possibility and probability of undiscovered deposits in covered terranes. To help characterize the size, resistivity, and depth of the mineral deposit concealed beneath thick overburden, a regional southwest-northeast audiomagnetotelluric sounding profile was acquired. Further studies will attempt to determine if induced polarization parameters can be extracted from the magnetotelluric data to determine the size of the mineralized area. The purpose of this report is to release the audiomagnetotelluric sounding data collected along that southwest-northeast profile. No interpretation of the data is included.

  18. Synthesis, physico-chemical characterization and biological activity of copper(ii and nickel(ii complexes with l-benzoyl-2-methylbenzimidazole derivatives

    Directory of Open Access Journals (Sweden)

    Podunavac-Kuzmanović Sanja O.

    2002-01-01

    Full Text Available Chlorides of copper(II and nickel(ll react with 1-benzoyl-2-methylbenzimidazole or 1-(4-chlorobenzoyl-2-methylbenzimidazole to give complexes of the type [M(LnCln(H20∙Cln (M = Cu or Ni; L = (1-benzoyl-2-methylbenzimidazole or 1-(4-chlorobenzoyl-2-methylbenzimidazole; n=O, 1 or 2. The complexes were synthesized and characterized by elemental analysis, molar conductivity magnetic susceptibility measurements and IR spectra. These studies suggest that all the complexes possess an octahedral stereochemistry. The antibacterial activity of (1-benzoyl-2-methylbenzimidazole or 1-(4-chlorobenzoyl-2-methylbenzimidazole and their complexes was evaluated against Escherichia coli and Bacillus sp.

  19. Synthesis, characterization and tin/copper-nitrogen substitutional effect on photocatalytic activity of honeycomb ordered P2-Na2Ni2TeO6

    Science.gov (United States)

    Kadari, Ramaswamy; Velchuri, Radha; Sreenu, K.; Ravi, Gundeboina; Munirathnam, Nagegownivari R.; Vithal, Muga

    2016-11-01

    We have successfully prepared visible light active tin/copper-nitrogen co-doped honeycomb ordered P2-Na2Ni2TeO6 photocatalysts by solid state/ion exchange methods. Powder XRD, TG analysis, SEM, surface area, O-N-H analysis, ICP-OES, FT-IR and UV-DRS measurements are employed to characterize all the samples. All the doped compositions adopted hexagonal lattice with space group P63/mcm. The photocatalytic activity of all the samples was studied against the degradation of methyl violet (MV) and methylene blue (MB) under visible light irradiation. The variation of the photocatalytic activity due to the substitution of cation, anion and co-doping in Na2Ni2TeO6 is investigated. Co-doped samples have exhibited higher activity compared to rest of the materials. The role of reactive intermediate species in the photocatalytic degradation of dyes is also studied using appropriate scavengers.

  20. Synthesis, Characterization and DFT-Based Investigation of a Novel Trinuclear Singly-Chloro-Bridged Copper(II)-1-Vinylimidazole Complex.

    Science.gov (United States)

    Yolcu, Zuhal; Demir, Serkan; Andaç, Ömer; Büyükgüngör, Orhan

    2016-01-01

    A novel trinuclear copper(II) complex [Cu3(μ-Cl)2Cl4(1-Vim)6] with monodentate 1-vinylimidazole (1-Vim) and chloro ligands has been prepared and experimentally characterized by elemental analysis, thermogravimetry (TGA, DTG, DTA), X-ray single crystal diffractometry, TOF-MS and FT-IR spectroscopies. The electronic and structural properties of the complex were further investigated by DFT/TD-DFT methods. Density functional hybrid method (B3LYP) was applied throughout the calculations. The calculated UV-Vis results based on TD-DFT approach were simulated and compared with experimental spectrum. Based on the data obtained, DFT calculations have been found in reasonable accordance with experimental data.

  1. Synthesis, characterization and magnetism of copper ( Ⅱ ) -lan-thanide(Ⅲ) heterobimetalic complexes with N, N'-oxamidobis-(benzoato) cuprate (Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    李延团; 曾宪诚; 焉翠蔚; 廖代正

    2000-01-01

    Seven new μ-oxamido copper(Ⅱ)-lanthanide(Ⅲ) hetero-bimetalic complexes complexes by the formula Cu(obbz)Ln-(Ph-phen)2NO3(Ln = La, Nd, Eu, Gd, Tb, Ho, Er),where obbz denotes the oxamidobis menzoatob) and Ph-phen represents 5-phenyl-1, 10-phenanthroline, have been synthesized and characterized by the elemental analyses, spectroscopic (IR, UV, ESR) studies, magnetic moments (at room temperature) and molar conducivity measurement. The temperature dependence of the magnetic susceptibility of Cu(ob-bz)Gd(Ph-phen)2NO3 complex has been measured over the range 4.2-300 K. The least-squares fit of experimental susceptibilities based on the spin Hamitonian, H=-2JS1- S2, yielded J = + 1.28 cm1, a weak ferromagnetic coupting. A plausible mechanism for a ferromagnetic coupling between Gd(Ⅲ)-Cu(Ⅱ) is discussed in terms of spin-polar-ization.

  2. Characterization and copper binding of humic and nonhumic organic matter isolated from the South Platte River: Evidence for the presence of nitrogenous binding site

    Science.gov (United States)

    Croue, J.-P.; Benedetti, M.F.; Violleau, D.; Leenheer, J.A.

    2003-01-01

    Humic substances typically constitute 40-60% of the dissolved organic matter (DOM) in surface waters. However, little information is available regarding the metal binding properties of the nonhumic hydrophilic portion of the DOM. In this study, humic and nonhumic DOM samples were isolated from the South Platte River (Colorado, DOC = 2.6 mg??L-1, SUVA254 = 2.4 L/mg??m) using a two-column array of XAD-8 and XAD-4 resins. The three major isolated fractions of DOM, which accounted for 57% of the bulk DOM, were characterized using a variety of analytical tools. Proton and copper binding properties were studied for each fraction. The main objective of this work was to compare the structural and chemical characteristics of the isolated fractions and test models describing DOM reactivity toward metal ions. The characterization work showed significant structural differences between the three isolated fractions of DOM. The hydrophobic acid fraction (i.e., humic substances isolated from the XAD-8 resin) gave the largest C/H, C/O, and C/N ratios and aromatic carbon content among the three isolated fractions. The transphilic acid (TPHA) fraction ("transphilic" meaning fraction of intermediate polarity isolated from the XAD-4 resin) was found to incorporate the highest proportion of polysaccharides, whereas the transphilic neutral (TPHN) fraction was almost entirely proteinaceous. The gradual increase of the charge with pH for the three DOM fractions is most likely caused by a large distribution of proton affinity constants for the carboxylic groups, as well as a second type of group more generally considered to be phenolic. In the case of the DOM fraction enriched in proteinaceous material (i.e., TPHN fraction), the results showed that the amino groups are reponsible for the charge reversal. For low copper concentrations, nitrogen-containing functional groups similar to those of amino acids are likely to be involved in complexation, in agreement with previously published data.

  3. Synthesis, characterization, crystal structure and antimicrobial activity of copper(II) complexes with the Schiff base derived from 2-hydroxy-4-methoxybenzaldehyde.

    Science.gov (United States)

    Pahonțu, Elena; Ilieș, Diana-Carolina; Shova, Sergiu; Paraschivescu, Codruța; Badea, Mihaela; Gulea, Aurelian; Roșu, Tudor

    2015-04-02

    A novel Schiff base, ethyl 4-[(E)-(2-hydroxy-4-methoxyphenyl)methylene-amino]benzoate (HL), was prepared and structurally characterized on the basis of elemental analyses, (1)H NMR, (13)C NMR, UV-Vis and IR spectral data. Six new copper(II) complexes, [Cu(L)(NO3)(H2O)2] (1), [Cu(L)2] (2), [Cu(L)(OAc)] (3), [Cu2 (L)2Cl2(H2O)4] (4), [Cu(L)(ClO4)(H2O)] (5) and [Cu2(L2S)(ClO4)(H2O)]ClO4·H2O (6) have been synthesized. The characterization of the newly formed compounds was done by IR, UV-Vis, EPR, FAB mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The crystal structures of Schiff base and the complex [Cu2(L2S)(ClO4)(H2O)]ClO4·H2O (6) have been determined by single crystal X-ray diffraction studies. Both copper atoms display a distorted octahedral coordination type [O4NS]. This coordination is ensured by three phenol oxygen, two of which being related to the µ-oxo-bridge, the nitrogen atoms of the azomethine group and the sulfur atoms that come from the polydentate ligand. The in vitro antimicrobial activity against Escherichia coli ATCC 25922, Salmonella enteritidis, Staphylococcus aureus ATCC 25923, Enterococcus and Candida albicans strains was studied and compared with that of free ligand. The complexes 1, 2, 5 showed a better antimicrobial activity than the Schiff base against the tested microorganisms.

  4. Flower-Like CuO/ZnO Hybrid Hierarchical Nanostructures Grown on Copper Substrate: Glycothermal Synthesis, Characterization, Hydrophobic and Anticorrosion Properties

    Directory of Open Access Journals (Sweden)

    Farshad Beshkar

    2017-06-01

    Full Text Available In this work we have demonstrated a facile formation of CuO nanostructures on copper substrates by the oxidation of copper foil in ethylene glycol (EG at 80 °C. On immersing a prepared CuO film into a solution containing 0.1 g Zn(acac2 in 20 mL EG for 8 h, ZnO flower-like microstructures composed of hierarchical three-dimensional (3D aggregated nanoparticles and spherical architectures were spontaneously formed at 100 °C. The as-synthesized thin films and 3D microstructures were characterized using XRD, SEM, and EDS techniques. The effects of sodium dodecyl sulphate (SDS, cetyltrimethylammonium bromide (CTAB, and polyethylene glycol (PEG 6000 as surfactants and stabilizers on the morphology of the CuO and ZnO structures were discussed. Possible growth mechanisms for the controlled organization of primary building units into CuO nanostructures and 3D flower-like ZnO architectures were proposed. The hydrophobic property of the products was characterized by means of water contact angle measurement. After simple surface modification with stearic acid and PDMS, the resulting films showed hydrophobic and even superhydrophobic characteristics due to their special surface energy and nano-microstructure morphology. Importantly, stable superhydrophobicity with a contact angle of 153.5° was successfully observed for CuO-ZnO microflowers after modification with PDMS. The electrochemical impedance measurements proved that the anticorrosion efficiency for the CuO/ZnO/PDMS sample was about 99%.

  5. Synthesis, Characterization, Crystal Structure and Antimicrobial Activity of Copper(II Complexes with the Schiff Base Derived from 2-Hydroxy-4-Methoxybenzaldehyde

    Directory of Open Access Journals (Sweden)

    Elena Pahonțu

    2015-04-01

    Full Text Available A novel Schiff base, ethyl 4-[(E-(2-hydroxy-4-methoxyphenylmethylene-amino]benzoate (HL, was prepared and structurally characterized on the basis of elemental analyses, 1H NMR, 13C NMR, UV-Vis and IR spectral data. Six new copper(II complexes, [Cu(L(NO3(H2O2] (1, [Cu(L2] (2, [Cu(L(OAc] (3, [Cu2 (L2Cl2(H2O4] (4, [Cu(L(ClO4(H2O] (5 and [Cu2(L2S(ClO4(H2O]ClO4·H2O (6 have been synthesized. The characterization of the newly formed compounds was done by IR, UV-Vis, EPR, FAB mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The crystal structures of Schiff base and the complex [Cu2(L2S(ClO4(H2O]ClO4·H2O (6 have been determined by single crystal X-ray diffraction studies. Both copper atoms display a distorted octahedral coordination type [O4NS]. This coordination is ensured by three phenol oxygen, two of which being related to the µ-oxo-bridge, the nitrogen atoms of the azomethine group and the sulfur atoms that come from the polydentate ligand. The in vitro antimicrobial activity against Escherichia coli ATCC 25922, Salmonella enteritidis, Staphylococcus aureus ATCC 25923, Enterococcus and Candida albicans strains was studied and compared with that of free ligand. The complexes 1, 2, 5 showed a better antimicrobial activity than the Schiff base against the tested microorganisms.

  6. Severe plastic deformation using friction stir processing, and the characterization of microstructure and mechanical behavior using neutron diffraction

    Science.gov (United States)

    Woo, Wanchuck

    Friction-stir welding (FSW) is a solid-state joining process, which utilizes a cylindrical rotating tool consisting of a concentric threaded tool pin and tool shoulder. The strong metallurgical bonding during the FSW is accomplished through: (1) the severe plastic deformation caused by the rotation of the tool pin that plunges into the material and travels along the joining line; and (2) the frictional heat generated mainly from the pressing tool shoulder. Recently, a number of variations of the FSW have been applied to modify the microstructure, for example, grain refinements and homogenization of precipitate particles, namely friction-stir processing (FSP). Applications of the FSP/FSW are widespread for the transportation industries. The microstructure and mechanical behavior of light-weight materials subjected to the FSW/FSP are being studied extensively. However, separating the effect of the frictional heat and severe plastic deformation on the residual stress and texture has been a standing problem for the fundamental understanding of FSW/FSP. The fundamental issues are: (i) the heat- and plastic-deformation-induced internal stresses that may be detrimental to the integrity and performance of components; (ii) the frictional heating that causes a microstructural softening due to the dissolution or growth of the precipitates in precipitation-hardenable Al alloys during the process; and (iii) the crystallographic texture can be significantly altered from the original texture, which could affect the physical and mechanical properties. The understanding of the influences of the de-convoluted sources (e.g. frictional heat, severe plastic deformation, or their combination) on the residual stress, microstructural softening, and texture variations during FSW can be used for a physicsvi based optimization of the processing parameters and new tool designs. Furthermore, the analyses and characterization of the natural aging behavior and the aging kinetics can be

  7. 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.

  8. Inspection of copper canisters for spent nuclear fuel by means of ultrasound. Electron beam evaluation, harmonic imaging, materials characterization, and ultrasonic modelling

    Energy Technology Data Exchange (ETDEWEB)

    Wu Ping; Lingvall, Fredrik; Stepinski, Tadeusz [Uppsala Univ. (Sweden). Dept. of Materials Science

    2000-12-01

    This report presents the research in the sixth phase that is concerned with ultrasonic techniques for assessing electron beam (EB) welds in copper canisters. The research has been carried out in three main aspects: (1) comparative inspections of EB welds, (2) EB weld evaluation, and (3) quantitative evaluation of attenuation in copper. Comparative inspections of EB welds in two copper canister blocks have been made by means of ultrasound and radiography. Comparison of the inspected results demonstrate that both techniques complement each other very well. The radiographic technique on the whole gives relatively better spatial resolution but low contrast in radiographs. It can reliably detect voids in EB, but cannot provide information about material structure in the EB weld. Ultrasonic technique provides information about flaw locations and shapes similar to the radiographs. Moreover, it can easily distinguish welded and non-welded zones and be used to study weld's macro- and microstructure. The defects in ultrasonic images often show higher contrast, and some flaw indications may be seen in ultrasonic inspection but not in radiographs. But small flaws are hard to distinguish from grain noise. For EB weld evaluation, first, scattering from EB weld has been investigated using three broadband transducers with different center frequencies. The investigation has shown that more information on scattering and attenuation can be exploited in this case so that the EB welds can be better characterized, and that the best frequency range for characterizing welds is 2 - 5 MHz. Secondly, harmonic imaging (HI) of EB welds have been studied using two different sources of harmonics: (i) transducer harmonics, originating from the high-order resonant modes of transmitters excited by a broadband pulse, and (ii) material harmonics, stemming from the nonlinear distortion of waves propagating in materials. The transducer HI exploits additional information due to transducer harmonics

  9. Characterization of a Highly Thermostable and Organic Solvent-Tolerant Copper-Containing Polyphenol Oxidase with Dye-Decolorizing Ability from Kurthia huakuii LAM0618T.

    Science.gov (United States)

    Guo, Xiang; Zhou, Shan; Wang, Yanwei; Song, Jinlong; Wang, Huimin; Kong, Delong; Zhu, Jie; Dong, Weiwei; He, Mingxiong; Hu, Guoquan; Ruan, Zhiyong

    2016-01-01

    Laccases are green biocatalysts that possess attractive advantages for the treatment of resistant environmental pollutants and dye effluents. A putative laccase-like gene, laclK, encoding a protein of 29.3 kDa and belonging to the Cu-oxidase_4 superfamily, was cloned and overexpressed in Escherichia coli. The purified recombinant protein LaclK (LaclK) was able to oxidize typical laccase substrates such as 2,6-dimethoxyphenol and l-dopamine. The characteristic adsorption maximums of typical laccases at 330 nm and 610 nm were not detected for LaclK. Cu2+ was essential for substrate oxidation, but the ratio of copper atoms/molecule of LaclK was determined to only be 1:1. Notably, the optimal temperature of LaclK was 85°C with 2,6-dimethoxyphenol as substrates, and the half-life approximately 3 days at 80°C. Furthermore, 10% (v/v) organic solvents (methanol, ethanol, isopropyl alcohol, butyl alcohol, Triton x-100 or dimethyl sulfoxide) could promote enzymatic activity. LaclK exhibited wide-spectrum decolorization ability towards triphenylmethane dyes, azo dyes and aromatic dyes, decolorizing 92% and 94% of Victoria Blue B (25 μM) and Ethyl Violet (25 μM), respectively, at a concentration of 60 U/L after 1 h of incubation at 60°C. Overall, we characterized a novel thermostable and organic solvent-tolerant copper-containing polyphenol oxidase possessing dye-decolorizing ability. These unusual properties make LaclK an alternative for industrial applications, particularly processes that require high-temperature conditions.

  10. Characterization of a Highly Thermostable and Organic Solvent-Tolerant Copper-Containing Polyphenol Oxidase with Dye-Decolorizing Ability from Kurthia huakuii LAM0618T

    Science.gov (United States)

    Guo, Xiang; Zhou, Shan; Wang, Yanwei; Song, Jinlong; Wang, Huimin; Kong, Delong; Zhu, Jie; Dong, Weiwei; He, Mingxiong; Hu, Guoquan; Ruan, Zhiyong

    2016-01-01

    Laccases are green biocatalysts that possess attractive advantages for the treatment of resistant environmental pollutants and dye effluents. A putative laccase-like gene, laclK, encoding a protein of 29.3 kDa and belonging to the Cu-oxidase_4 superfamily, was cloned and overexpressed in Escherichia coli. The purified recombinant protein LaclK (LaclK) was able to oxidize typical laccase substrates such as 2,6-dimethoxyphenol and l-dopamine. The characteristic adsorption maximums of typical laccases at 330 nm and 610 nm were not detected for LaclK. Cu2+ was essential for substrate oxidation, but the ratio of copper atoms/molecule of LaclK was determined to only be 1:1. Notably, the optimal temperature of LaclK was 85°C with 2,6-dimethoxyphenol as substrates, and the half-life approximately 3 days at 80°C. Furthermore, 10% (v/v) organic solvents (methanol, ethanol, isopropyl alcohol, butyl alcohol, Triton x-100 or dimethyl sulfoxide) could promote enzymatic activity. LaclK exhibited wide-spectrum decolorization ability towards triphenylmethane dyes, azo dyes and aromatic dyes, decolorizing 92% and 94% of Victoria Blue B (25 μM) and Ethyl Violet (25 μM), respectively, at a concentration of 60 U/L after 1 h of incubation at 60°C. Overall, we characterized a novel thermostable and organic solvent-tolerant copper-containing polyphenol oxidase possessing dye-decolorizing ability. These unusual properties make LaclK an alternative for industrial applications, particularly processes that require high-temperature conditions. PMID:27741324

  11. Growth and characterization of Bis(L-threonine) copper (II) monohydrate single crystals: A semiorganic second order nonlinear optical material

    Science.gov (United States)

    Subhashini, R.; Sathya, D.; Sivashankar, V.; Latha Mageshwari, P. S.; Arjunan, S.

    2016-12-01

    Highly transparent solitary nonlinear semiorganic optical material Bis(L-threonine) copper (II) monohydrate [BLTCM], was synthesized by a conventional slow evaporation solution growth technique. The grown crystals were subjected to structural, optical, electrical, thermal, mechanical, SHG and Laser damage threshold studies. Single crystal XRD shows that the material crystallizes in monoclinic system with noncentrosymmetric space group P21. FT-IR and FT-RAMAN analyses confirm the various functional groups present in the grown crystal. The transparency range of BLTCM was determined by UV-vis-NIR studies and various optical constants such as extinction coefficient (K), refractive index, optical conductivity and electric susceptibility with real and imaginary parts of dielectric constant were calculated using the transmittance data which have applications in optoelectronic devices. Dielectric studies of the crystal were carried out at different frequencies and temperatures to analyze the electrical properties. TGA and DSC analyses were performed to study the thermal behaviour of the sample. The hardness stability of the grown specimen was investigated by Vickers microhardness test. The output intensity of second harmonic generation was confirmed using the Kurtz and Perry powder method. The laser induced surface damage threshold of the crystal was measured using Nd:YAG laser.

  12. Characterization of laser doped silicon and overcoming adhesion challenges of solar cells with nickel-copper plated contacts

    Energy Technology Data Exchange (ETDEWEB)

    Geisler, Christian

    2015-07-01

    The combination of localized laser patterning and metal plating allows to replace conventional silver screen printing with nickel-copper plating to form inexpensive front contacts for crystalline silicon solar cells. In this work, a focus is put on effects that could cause inhomogeneous metal deposition and low metal contact adhesion. A descriptive model of the silicon nitride ablation mechanism is derived from SEM imaging and a precise recombination analysis using QSSPC measurements. Surface sensitive XPS measurements are conducted to prove the existence of a parasitic surface layer, identified as SiO{sub x}N{sub y}. The dense SiO{sub x}N{sub y} layer is an effective diffusion barrier, hindering the formation of a nickel silicide interlayer. After removal of the SiO{sub x}N{sub y} layer, cells show severe degradation caused by metal-induced shunting. These shunts are imaged using reverse biased electroluminescence imaging. A shunting mechanism is proposed and experimentally verified. New laser process sequences are devised and proven to produce cells with adhering Ni-Cu contacts. Conclusively the developed processes are assessed based on their industrial feasibility as well as on their efficiency potential.

  13. Experimental and numerical optical characterization of plasmonic copper nanoparticles embedded in ZnO fabricated by ion implantation and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Le, Khai Q. [Faculty of Science and Technology, Hoa Sen University, Ho Chi Minh City (Viet Nam); Department of Physics, Faculty of Science, Jazan University, P.O. Box 114, 45142 Jazan (Saudi Arabia); Nguyen, Hieu P.T. [Department of Electrical and Computer Engineering, New Jersey Institute of Technology, NJ 07102 (United States); Ngo, Quang Minh [Institute of Material Sciences, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi (Viet Nam); Canimoglu, Adil [Nigde University, Faculty of Arts and Sciences, Physics Department, Nigde (Turkey); Can, Nurdogan, E-mail: cannurdogan@yahoo.com [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, Muradiye, Manisa (Turkey); Department of Physics, Faculty of Science, Jazan University, P.O. Box 114, 45142 Jazan (Saudi Arabia)

    2016-06-05

    Here we describe the successfully fabrication of metal nanoparticle crystals by implanting copper (Cu) ions into single zinc oxide (ZnO) crystals with ion energy of 400 keV at ion doses of 1 × 10{sup 16} to 1 × 10{sup 17} ions/cm{sup 2}. After implantation and post-annealing treatment, the Cu implanted ZnO produces a broad range of luminescence emissions, ranging from green to yellow. A green luminescence peak at 550 nm could be ascribed to the isolated Cu ions. The changes in luminescence emission bands between the initial implant and annealed suggest that the implants give rise to clustering Cu nanoparticles in the host matrix but that the annealing process dissociates these. Numerical modelling of the Cu nanoparticles was employed to simulate their optical properties including the extinction cross section, electron energy loss spectroscopy and cathodoluminescence. We demonstrate that the clustering of nanoparticles generates Fano resonances corresponding to the generation of multiple resonances, while the isolation of nanoparticles results in intensity amplification. - Highlights: • We present the fabrication of metal nanoparticle crystals by implanting Cu into ZnO. • The luminescence properties were studied at different annealing temperature. • Numerical modelling of the Cu nanoparticles was employed. • We demonstrate that the clustering of nanoparticles generates Fano resonances.

  14. Structural characterization of copper(II) binding to alpha-synuclein: Insights into the bioinorganic chemistry of Parkinson's disease.

    Science.gov (United States)

    Rasia, Rodolfo M; Bertoncini, Carlos W; Marsh, Derek; Hoyer, Wolfgang; Cherny, Dmitry; Zweckstetter, Markus; Griesinger, Christian; Jovin, Thomas M; Fernández, Claudio O

    2005-03-22

    The aggregation of alpha-synuclein (AS) is characteristic of Parkinson's disease and other neurodegenerative synucleinopathies. We demonstrate here that Cu(II) ions are effective in accelerating AS aggregation at physiologically relevant concentrations without altering the resultant fibrillar structures. By using numerous spectroscopic techniques (absorption, CD, EPR, and NMR), we have located the primary binding for Cu(II) to a specific site in the N terminus, involving His-50 as the anchoring residue and other nitrogen/oxygen donor atoms in a square planar or distorted tetragonal geometry. The carboxylate-rich C terminus, originally thought to drive copper binding, is able to coordinate a second Cu(II) equivalent, albeit with a 300-fold reduced affinity. The NMR analysis of AS-Cu(II) complexes reveals the existence of conformational restrictions in the native state of the protein. The metallobiology of Cu(II) in Parkinson's disease is discussed by a comparative analysis with other Cu(II)-binding proteins involved in neurodegenerative disorders.

  15. Synthesis and characterization of copper(ii) complexes with multidentate ligands as catalysts for the direct hydroxylation of benzene to phenol.

    Science.gov (United States)

    Wu, Li; Zhong, Wei; Xu, Beibei; Wei, Zhenhong; Liu, Xiaoming

    2015-05-07

    Four copper(ii) complexes with multidentate ligands, ([CuL1Cl2]), ([Cu(HL2)Cl2]), ([Cu2(L2)2](ClO4)2) and ([CuL3(HOCH3)ClO4]) {L1 = N,N-bis((pyridin-2-yl)methyl) prop-2-yn-1-amine, HL2 = 2-((((1-methyl-1H-imidazol-2-yl)methyl)(pyridin-2-ylmethyl)amino)methyl)phenol and HL3 = 2-((((1-methyl-1H-imidazol-2-yl)methyl)(pyridin-2-ylmethyl)amino)methyl)-2-t-butyl-phenol} are reported. The complexes were characterized by UV-vis spectroscopy, elemental analysis and electrochemical analysis. Complexes and were further characterized by X-ray single crystal diffraction analysis. The catalytic performances of these complexes were evaluated in the direct hydroxylation of benzene to phenol with hydrogen peroxide as an oxidant in aqueous acetonitrile media. Under optimized reaction conditions, complex with the most negative reduction potential exhibited the highest conversion without considering the dinuclear complex . A correlation between the catalytic efficiency and the reduction potentials of these complexes was observed, that is the more negative the reduction potential, the higher the benzene conversion. A radical mechanism for the catalysis was confirmed by the fact that addition of radical scavengers such as TEMPO into the reaction mixture could severely suppress the catalysis.

  16. Synthesis, spectroscopic and X-ray characterization of a copper(II) complex with the Schiff base derived from pyridoxal and aminoguanidine: NMR spectral studies of the ligand.

    Science.gov (United States)

    Leovac, Vukadin M; Joksović, Milan D; Divjaković, Vladimir; Jovanović, Ljiljana S; Saranović, Zana; Pevec, Andrej

    2007-07-01

    A copper(II) complex with the pyridoxal-aminoguanidine (PL-AG) Schiff base adduct, as an organic compound of the very potent biological activity and promising pharmacological importance in the treatment of diabetic complications, has been prepared and characterized. The X-ray structural analysis of the [CuCl2(PL-AG)] complex showed that it has a distorted pseudo-square-pyramidal (4+1) structure with the tridentate ONN Schiff base in the equatorial plane, with the Cu-O(1), Cu-N(1) and Cu-N(3) bond lengths of 1.917(2)A, 1.930(2)A and 1.984(2)A, respectively. The bond length of the equatorial Cu-Cl(1) is 2.279(1)A, while that of the apical Cu-Cl(2) is 2.792(1)A. Pyridoxal fragment is coordinated in its zwitterionic form. In addition to the X-ray structural analysis, the complex was characterized by IR spectrometric, conductometric and magnetic techniques, and the ligand itself by IR, 1H and 13C NMR spectra.

  17. A novel nanostructured composite formed by interaction of copper octa(3-aminopropyl)octasilsesquioxane with azide ligands: Preparation, characterization and a voltammetric application

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro do Carmo, Devaney, E-mail: docarmo@dfq.feis.unesp.br [Faculdade de Engenharia de Ilha Solteira UNESP - Univ Estadual Paulista, Departamento de Fisica e Quimica, Av. Brasil Centro, 56 CEP 15385-000, Ilha Solteira, SP (Brazil); Paim, Leonardo Lataro [Instituto de Quimica de Araraquara UNESP - Univ Estadual Paulista, Rua Francisco Degni s/n, CEP 14801-970, Araraquara, SP (Brazil); Metzker, Gustavo [Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Sao-carlense, 400, 13566-590 Sao Carlos, SP (Brazil); Dias Filho, Newton Luiz [Faculdade de Engenharia de Ilha Solteira UNESP - Univ Estadual Paulista, Departamento de Fisica e Quimica, Av. Brasil Centro, 56 CEP 15385-000, Ilha Solteira, SP (Brazil); Stradiotto, Nelson Ramos [Instituto de Quimica de Araraquara UNESP - Univ Estadual Paulista, Rua Francisco Degni s/n, CEP 14801-970, Araraquara, SP (Brazil)

    2010-09-15

    This study presents the preparation, characterization and application of copper octa(3-aminopropyl)octasilsesquioxane following its subsequent reaction with azide ions (ASCA). The precursor (AC) and the novel compound (ASCA) were characterized by Fourier transform infrared spectra (FTIR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), scanning electronic microscopy (SEM), X-ray diffraction (XRD), Thermogravimetric analyses and voltammetric technique. The cyclic voltammogram of the modified graphite paste electrode with ASCA (GPE-ASCA), showed one redox couple with formal potential (E{sub 1/2}{sup ox}) = 0.30 V and an irreversible process at 1.1 V (vs. Ag/AgCl; NaCl 1.0 M; v=20mVs{sup -1}). The material is very sensitive to nitrite concentrations. The modified graphite paste electrode (GPE-ASCA) gives a linear range from 1.0 x 10{sup -4} to 4.0 x 10{sup -3} mol L{sup -1} for the determination of nitrite, with a detection limit of 2.1 x 10{sup -4} mol L{sup -1} and the amperometric sensitivity of 8.04 mA/mol L{sup -1}.

  18. Geochemical Characterization of Mine Waste, Mine Drainage, and Stream Sediments at the Pike Hill Copper Mine Superfund Site, Orange County, Vermont

    Science.gov (United States)

    Piatak, Nadine M.; Seal, Robert R.; Hammarstrom, Jane M.; Kiah, Richard G.; Deacon, Jeffrey R.; Adams, Monique; Anthony, Michael W.; Briggs, Paul H.; Jackson, John C.

    2006-01-01

    The Pike Hill Copper Mine Superfund Site in the Vermont copper belt consists of the abandoned Smith, Eureka, and Union mines, all of which exploited Besshi-type massive sulfide deposits. The site was listed on the U.S. Environmental Protection Agency (USEPA) National Priorities List in 2004 due to aquatic ecosystem impacts. This study was intended to be a precursor to a formal remedial investigation by the USEPA, and it focused on the characterization of mine waste, mine drainage, and stream sediments. A related study investigated the effects of the mine drainage on downstream surface waters. The potential for mine waste and drainage to have an adverse impact on aquatic ecosystems, on drinking- water supplies, and to human health was assessed on the basis of mineralogy, chemical concentrations, acid generation, and potential for metals to be leached from mine waste and soils. The results were compared to those from analyses of other Vermont copper belt Superfund sites, the Elizabeth Mine and Ely Copper Mine, to evaluate if the waste material at the Pike Hill Copper Mine was sufficiently similar to that of the other mine sites that USEPA can streamline the evaluation of remediation technologies. Mine-waste samples consisted of oxidized and unoxidized sulfidic ore and waste rock, and flotation-mill tailings. These samples contained as much as 16 weight percent sulfides that included chalcopyrite, pyrite, pyrrhotite, and sphalerite. During oxidation, sulfides weather and may release potentially toxic trace elements and may produce acid. In addition, soluble efflorescent sulfate salts were identified at the mines; during rain events, the dissolution of these salts contributes acid and metals to receiving waters. Mine waste contained concentrations of cadmium, copper, and iron that exceeded USEPA Preliminary Remediation Goals. The concentrations of selenium in mine waste were higher than the average composition of eastern United States soils. Most mine waste was

  19. Avaliação da geometria de ferramenta e parâmetros do processo FSW na soldagem da liga de alumínio AA 5052

    OpenAIRE

    2009-01-01

    A soldagem de ligas de alumínio sem degradação excessiva das propriedades originais do metal base apresenta-se como um obstáculo a ser superado pelas indústrias em seus processos de fabricação, uma vez que o alumínio tem sido usado cada vez de forma mais intensiva. Neste sentido, o processo de soldagem denominado Friction Stir Welding (FSW) tem recebido atenção por suas potencialidades onde o aporte de calor deve ser minimizado ou quando metais dissimilares devem ser soldados. Neste processo,...

  20. Characterization of exoelectrogenic bacteria enterobacter strains isolated from a microbial fuel cell exposed to copper shock load.

    Directory of Open Access Journals (Sweden)

    Cuijie Feng

    Full Text Available Microorganisms capable of generating electricity in microbial fuel cells (MFCs have gained increasing interest. Here fourteen exoelectrogenic bacterial strains were isolated from the anodic biofilm in an MFC before and after copper (Cu shock load by Hungate roll-tube technique with solid ferric (III oxide as an electron acceptor and acetate as an electron donor. Phylogenetic analysis of the 16S rRNA gene sequences revealed that they were all closely related to Enterobacter ludwigii DSM 16688T within the Enterobacteriaceae family, although these isolated bacteria showed slightly different morphology before and after Cu shock load. Two representative strains R2B1 (before Cu shock load and B4B2 (after Cu shock load were chosen for further analysis. B4B2 is resistant to 200 mg L-1 of Cu(II while R2B1 is not, which indicated the potential selection of the Cu shock load. Raman analysis revealed that both R2B1 and B4B2 contained c-type cytochromes. Cyclic voltammetry measurements revealed that strain R2B1 had the capacity to transfer electrons to electrodes. The experimental results demonstrated that strain R2B1 was capable of utilizing a wide range of substrates, including Luria-Bertani (LB broth, cellulose, acetate, citrate, glucose, sucrose, glycerol and lactose to generate electricity, with the highest current density of 440 mA·m-2 generated from LB-fed MFC. Further experiments indicated that the bacterial cell density had potential correlation with the current density.

  1. Synthesis, characterization and quantitative analysis of porous metal microstructures: Application to microporous copper produced by solid state foaming

    Directory of Open Access Journals (Sweden)

    Mark A. Atwater

    2016-05-01

    Full Text Available Porous metals can be created through a wide variety of processing techniques, and the pore morphology resulting from these processes is equally diverse. The structural and functional properties of metal foams are directly dependent on the size, shape, interconnectedness and volume fraction of pores, so accurately quantifying the pore characteristics is of great importance. Methods for analyzing porous materials are presented here and applied to a copper-based metallic foam generated through solid state foaming via oxide reduction and expansion. This process results in large voids (10s of microns between sintered particles and small pores (10 microns to less than 50 nm within particles. Optical and electron microscopy were used to image the porosity over this wide range, and the pore characteristics were quantified using image segmentation and statistical analysis. Two-dimensional pore analysis was performed using the Chan-Vese method, and two-point correlation and lineal path functions were used to assess three-dimensional reconstructions from FIB tomography. Two-dimensional analysis reveals distinct size and morphological differences in porosity between particles and within them. Three-dimensional analysis adds further information on the high level interconnectedness of the porosity and irregular shape it takes, forming tortuous pathways rather than spherical cells. Mechanical polishing and optical microscopy allow large areas to be created and analyzed quickly, but methods such as focused ion beam (FIB sectioning can provide additional insight about microstructural features. In particular, after FIB milling is used to create a flat surface, that surface can be analyzed for structural and compositional information.

  2. Molecular characterization of a cDNA encoding copper/zinc superoxide dismutase from cultured cells of Manihot esculenta.

    Science.gov (United States)

    Shin, Seung-Yong; Lee, Haeng-Soon; Kwon, Suk-Yoon; Kwon, Soon-Tae; Kwak, Sang-Soo

    2005-01-01

    Superoxide dismutase (SOD) cDNA, mSOD2, encoding cytosolic copper/zinc SOD (CuZnSOD) cDNA was isolated from suspension-cultured cells of cassava (Manihot esculenta Crantz) by cDNA library screening, and its expression was investigated in relation to environmental stress. mSOD2 is 774 bp in length with an open reading frame (ORF) of 152 amino acids, corresponding to a protein of predicted molecular mass 15 kDa and a pI of 5.22. One copy of the mSOD2 gene was found to be present in the cassava genome by Southern analysis using an mSOD2 cDNA-specific probe. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed diverse expression patterns for the mSOD2 gene in various tissues of intact cassava plants, at various stages of the growth in suspension cultures, and in the leaf tissues exposed to different stresses. The mSOD2 gene was highly expressed in suspension-cultured cells and in the stems of intact plants. However, it was expressed at low levels in leaves and roots. During suspension cell growth, the mSOD2 transcript progressively increased during culture. Moreover, the mSOD2 gene in excised cassava leaves responded to various stresses in different ways. In particular, it was highly induced in leaf tissue by several abiotic stresses, including high temperature (37 degrees C), chilling (4 degrees C), methyl viologen (MV) exposure, and wounding treatment. These results indicate that the mSOD2 gene is involved in the antioxidative process triggered by oxidative stress induced by environmental change.

  3. Copper substitutions in synthetic miargyrite α-AgSbS{sub 2} mineral: Synthesis, characterization and dielectrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Galdámez, A., E-mail: agaldamez@uchile.cl [Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); López-Vergara, F.; Veloso Cid, N.; Manríquez, V. [Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Ávila, R.E. [Departamento de Producción y Servicios, Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile)

    2014-02-14

    The nominal compositions Ag{sub 0.8}Cu{sub 0.2}SbS{sub 2} and Ag{sub 0.7}Cu{sub 0.3}SbS{sub 2} have been synthesized by conventional ceramic solid-state reaction at high temperature. X-ray diffraction (XRD) and scanning electron microscopy chemical analysis (SEM-EDAX) revealed single phases, isostructural to the natural miargyrite α-AgSbS{sub 2} mineral. Examination of the lattice parameters shows a decrease in the cell volume with increasing copper substitutions. The Raman analysis displays absorptions which may be assigned to the Sb–S stretching vibrations of the SbS{sub 3} pyramids. The impedance-frequency analysis showed grain boundary and electrode interface contributions in non-Debye type relaxation, following Jonscher's universal power law. The giant permittivity response is attributed to extrinsic effects without evidence of a ferroelectric transition. Summerfield scaling, leading to the superposition of impedance analysis, implies that the relaxation is thermally activated, without introducing more than one underlying transport mechanism. - Highlights: • Ag{sub 0.8}Cu{sub 0.2}SbS{sub 2} and Ag{sub 0.7}Cu{sub 0.3}SbS{sub 2} are isostructural with the natural miargyrite α-AgSbS{sub 2} mineral. • The overall resistance correspond to grain boundary and electrode/sample interface responses. • In these solid solutions no ferroelectric-like transition is noticed. • The overall frequency dependence follows the Jonscher's universal power law. • σ{sub ac} vs. frequency can be normalized by Summerfield scaling procedure.

  4. Characterization of exoelectrogenic bacteria enterobacter strains isolated from a microbial fuel cell exposed to copper shock load.

    Science.gov (United States)

    Feng, Cuijie; Li, Jiangwei; Qin, Dan; Chen, Lixiang; Zhao, Feng; Chen, Shaohua; Hu, Hongbo; Yu, Chang-Ping

    2014-01-01

    Microorganisms capable of generating electricity in microbial fuel cells (MFCs) have gained increasing interest. Here fourteen exoelectrogenic bacterial strains were isolated from the anodic biofilm in an MFC before and after copper (Cu) shock load by Hungate roll-tube technique with solid ferric (III) oxide as an electron acceptor and acetate as an electron donor. Phylogenetic analysis of the 16S rRNA gene sequences revealed that they were all closely related to Enterobacter ludwigii DSM 16688T within the Enterobacteriaceae family, although these isolated bacteria showed slightly different morphology before and after Cu shock load. Two representative strains R2B1 (before Cu shock load) and B4B2 (after Cu shock load) were chosen for further analysis. B4B2 is resistant to 200 mg L-1 of Cu(II) while R2B1 is not, which indicated the potential selection of the Cu shock load. Raman analysis revealed that both R2B1 and B4B2 contained c-type cytochromes. Cyclic voltammetry measurements revealed that strain R2B1 had the capacity to transfer electrons to electrodes. The experimental results demonstrated that strain R2B1 was capable of utilizing a wide range of substrates, including Luria-Bertani (LB) broth, cellulose, acetate, citrate, glucose, sucrose, glycerol and lactose to generate electricity, with the highest current density of 440 mA·m-2 generated from LB-fed MFC. Further experiments indicated that the bacterial cell density had potential correlation with the current density.

  5. Micro friction stir welding of copper electrical contacts

    Directory of Open Access Journals (Sweden)

    D. Klobčar

    2014-10-01

    Full Text Available The paper presents an analysis of micro friction stir welding (μFSW of electrolytic tough pitch copper (CuETP in a lap and butt joint. Experimental plan was done in order to investigate the influence of tool design and welding parameters on the formation of defect free joints. The experiments were done using universal milling machine where the tool rotation speed varied between 600 and 1 900 rpm, welding speed between 14 and 93 mm/min and tilt angle between 3° and 5°. From the welds samples for analysis of microstructure and samples for tensile tests were prepared. The grain size in the nugget zone was greatly reduced compared to the base metal and the joint tensile strength exceeded the strength of the base metal.

  6. In situ Fabrication of Monolithic Copper Azide

    Science.gov (United States)

    Li, Bing; Li, Mingyu; Zeng, Qingxuan; Wu, Xingyu

    2016-04-01

    Fabrication and characterization of monolithic copper azide were performed. The monolithic nanoporous copper (NPC) with interconnected pores and nanoparticles was prepared by decomposition and sintering of the ultrafine copper oxalate. The preferable monolithic NPC can be obtained through decomposition and sintering at 400°C for 30 min. Then, the available monolithic NPC was in situ reacted with the gaseous HN3 for 24 h and the monolithic NPC was transformed into monolithic copper azide. Additionally, the copper particles prepared by electrodeposition were also reacted with the gaseous HN3 under uniform conditions as a comparison. The fabricated monolithic copper azide was characterized by Fourier transform infrared (FTIR), inductively coupled plasma-optical emission spectrometry (ICP-OES), and differential scanning calorimetry (DSC).

  7. Preparation, Characterization and Photocatalytic Production Activity of Copper Doped TiO2%铜掺杂TiO2的制备、表征及光催化产氢性能

    Institute of Scientific and Technical Information of China (English)

    郑先君; 赵建波; 黄娟; 魏明宝; 谢冰; 王建林

    2012-01-01

    研究制备了高活性的铜掺杂二氧化钛光催化剂,并采用X射线衍射(XRD)和紫外-可见漫反射光谱(UV-Vis DRS)对其进行了表征.以葡萄糖为电子供体,系统地研究了铜掺杂量、煅烧温度、葡萄糖初始浓度对二氧化钛光催化产氢性能的影响.结果表明:少量铜离子掺杂对二氧化钛的晶相无影响,但能显著地改善其光吸收性能.最佳的铜掺杂量为3%,该催化剂4h的产氢量达25 mL,是纯二氧化钛产氢量的近2倍.%Degradation of organic substance and simultaneous recovery of hydrogen gas as renewable energy can proceed via photocatalytic technology with the use of TiO2. The copper doped TiO2 photocatalyst with high activity is prepared and characterized by XRD and UV - Vis DRS in this study. Using glucose as electron donor, effects of copper loading, calcination temperature and glucose initial concentration on photocatalytic - H2 production activity are systematically studied. Experimental results show that the phase structure of TiO2 makes no change after doping with small amount of copper. At the same time, the light-absorption ability of copper doped TiO2 can be greatly improved. The optimum dosage of copper is 3%. Hydrogen production over copper doped TiO2 (optimum dosage = 3% ) under 4 h irradiation is 25 mL, about two times longer than that of pure TiO2.

  8. Synthesis and characterization of a chiral dimeric copper(II) complex: Crystal structure of [Cu2(-Cl)2(HL)2].H2O(H2L = -(-)-2-[(2-hydroxy-1-phenyl-ethylimino)-methyl]-phenol)

    Indian Academy of Sciences (India)

    Chullikkattil P Pradeep; Panthapally S Zacharias; Samar K Das

    2005-03-01

    Synthesis and characterization of an optically active binuclear dichloro-bridged copper(II) complex [Cu2(-Cl)2(HL)2]$\\cdot$H2O 1 (H2L = -(-)-2-[(2-hydroxy-1-phenyl-ethylimino)-methyl]-phenol) of a Schiff-base derived from salicylaldehyde and ()-(+)-2-phenylglycinol are described. Compound 1 crystallizes in the orthorhombic chiral P212121 space group with = 4, = 10.21(2), = 11.574(3), = 25.364(9). Each copper shows square pyramidal geometry with O2NCl2 coordination and the Cu2Cl2 core geometry adopts a butterfly shape. Crystals of 1 were further characterized by elemental analysis, IR, UV-visible and EPR spectroscopy and circular dichroism (CD) studies.

  9. Prediction of the Grain-Microstructure Evolution Within a Friction Stir Welding (FSW) Joint via the Use of the Monte Carlo Simulation Method

    Science.gov (United States)

    Grujicic, M.; Ramaswami, S.; Snipes, J. S.; Avuthu, V.; Galgalikar, R.; Zhang, Z.

    2015-09-01

    A thermo-mechanical finite element analysis of the friction stir welding (FSW) process is carried out and the evolution of the material state (e.g., temperature, the extent of plastic deformation, etc.) monitored. Subsequently, the finite-element results are used as input to a Monte-Carlo simulation algorithm in order to predict the evolution of the grain microstructure within different weld zones, during the FSW process and the subsequent cooling of the material within the weld to room temperature. To help delineate different weld zones, (a) temperature and deformation fields during the welding process, and during the subsequent cooling, are monitored; and (b) competition between the grain growth (driven by the reduction in the total grain-boundary surface area) and dynamic-recrystallization grain refinement (driven by the replacement of highly deformed material with an effectively "dislocation-free" material) is simulated. The results obtained clearly revealed that different weld zones form as a result of different outcomes of the competition between the grain growth and grain refinement processes.

  10. Synthesis and Characterization of Heteronuclear Copper(II-Lanthanide(III Complexes of N,N′-1,3-Propylenebis(Salicylaldiminato Where Lanthanide(III = Gd or Eu

    Directory of Open Access Journals (Sweden)

    Longjam Jaideva Singh

    2013-01-01

    Full Text Available Three complexes, namely, [Cu(salbn] (1, [Cu(salbnGd(NO33·H2O] (2, and [Cu(salbnEu(NO33·H2O] (3 where salbn = N,N′-1,3-propylenebis (salicylaldiminato have been synthesized and characterized by elemental analyses, ICP-AES, IR, UV, NMR, MS, EDX, powder XRD, and EPR spectroscopies. The EDX results suggest the presence of two different metal ions in heteronuclear complexes (2 and (3. The ligand(salbn, complex (1, and complex (3 crystallize in triclinic system while complex (2 crystallizes in monoclinic system. The EPR studies suggest that [Cu(salbn] complex is tetragonally coordinated monomeric copper(II complex with unpaired electron in the dx2-y2 orbital and spectral features that are the characteristics of axial symmetry while complex (2 in DMF solution at liquid nitrogen temperature exhibits an anisotropic broad signal around g ~ 2.03 which may suggest a weak magnetic spin-exchange interaction between Gd(III and Cu(II ions. The fluorescence intensity of Eu(III decreased markedly in the complex (3.

  11. Synthesis and Characterization of Divalent Nickel, Copper and Cadmium Complexes of N-(2-2-[1-(3-aminophenyl ethylidene] hydrazino-2-oxoethyl Benzamide

    Directory of Open Access Journals (Sweden)

    Th. Promila Devi

    2014-12-01

    Full Text Available Complexes of Ni(II (1, Cu(II (2 and Cd(II (3 with a novel Schiff base N-(2-2-[1-(3-aminophenyl ethylidene] hydrazino-2-oxoethyl benzamide (LH have been prepared and characterized by elemental analysis, TG-DTA, magnetic, electronic, molar conductivity measurements, IR, SEM, NMR, ESR and mass studies. It is observed that all the complexes having 1:1 metal-ligand stoichiometry are tetracoordinated. The result shows that LH binds to Cu and Cd ions through the hydrazidic carbonyl oxygen, azomethine nitrogen and amine nitrogen as a tridentate ligand while with Ni ion, it coordinates as a bidentate species through the hydrazidic carbonyl oxygen and azomethine nitrogen. The ligand exhibits keto-enol tautomerism in 2 in which it acts as a uninegative ligand. Complexes 1 and 3 behave as 1:1 electrolytes in DMF solution while complex 2, as a nonelectrolyte. Complex 2 is diamagnetic and ESR inactive which suggest that copper ion is present in its cuprous form. SEM images are used to observe external morphology of the compounds.

  12. Synthesis and characterization of copper porphyrin into SBA-16 through "ship in a bottle" method: A catalyst for photo oxidation reaction under visible light

    Science.gov (United States)

    Najafian, Ahmad; Rabbani, Mahboubeh; Rahimi, Rahmatollah; Deilamkamar, Mehdi; Maleki, Ali

    2015-08-01

    In this study, the SBA-16 was synthesized and modified by 3-aminopropyltriethoxysilane. Then, the copper (II) meso-tetrakis(4-chlorophenyl)porphyrin (CuTClPP) was immobilized into SBA-16 (CuTClPP@SBA-16) by using ship in a bottle method. The synthesized mesoporous materials and heterogeneous catalyst were characterized by Fourier transform infrared (FT-IR), diffuse reflectance spectroscopy (DRS), X-Ray diffraction (XRD), N2 adsorption-desorption (BET), elemental analysis (CHN), electron disperse X-ray (EDX), inductively coupled plasma (ICP-AES) and scanning electron microscope (SEM). The catalytic activity of the obtained catalyst was examined in the oxidation of cyclohexene with t-butyl hydroperoxide (TBHP) and hydrogen peroxide (H2O2) as oxidants. The obtained products were determined by using gas chromatography (GC). The effect of visible light on oxidation efficiency was evaluated and results showed that the activity of catalyst increased under visible light. In addition, leaching and recycling experiments revealed that the catalyst can be repeatedly applied for cyclohexene oxidation for three successive cycles.

  13. Synthesis and characterization of bis-(2-cyano-1-methyl-3-{2- {{(5-methylimidazol-4-yl)methyl}thio}ethyl)guanidine copper(II) sulfate tetrahydrate

    Science.gov (United States)

    Rahardjo, Sentot B.; Endah Saraswati, Teguh; Pramono, Edy; Fitriana, Nur

    2016-02-01

    Complex of copper(II) with 2-cyano-1-methyl-3-{2-{{(5-methylimidazol-4- yl)methyl}thio}ethyl)guanidin(xepamet) had been synthesized in 1 : 4 mole ratio of metal to the ligand in methanol. The complex was characterized by metal analysis, thermal gravimetry/differential thermal analyzer (TG/DTA), molar conductivity meter, (Fourier transform infrared spectroscopy) FT-IR, UV-Vis spectroscopy, and magnetic susceptibility balance. The molar conductivity measurement shows that the complex was 2: 1 for electrolyte and SO42- which was acting as a counter ion. The thermal analysis by Thermogravimetric (TG) indicates that the complex contained four molecules of H2O. The Infrared spectral data indicates that functional groups of (C=N) imidazole and (C-S) are coordinated to the center ion Cu2+. Magnetic moment measurement shows that the complex is paramagnetic with peff = 1.78 ± 0.01 BM. Electronic spectra of the complex show a broad band at 608 nm (16447.23 cm-1) are due to Eg→T2g transition. Based on those of characteristics, The complex formula was estimated as [Cu(xepamet)2]SO4.4H2O. The structure of [Cu(xepamet)2]SO4.4H2O complex is probably square planar.

  14. Synthesis, physicochemical and spectroscopic characterization of copper(II)-polysaccharide pullulan complexes by UV-vis, ATR-FTIR, and EPR.

    Science.gov (United States)

    Mitić, Zarko; Cakić, Milorad; Nikolić, Goran M; Nikolić, Ružica; Nikolić, Goran S; Pavlović, Radmila; Santaniello, Enzo

    2011-02-15

    Bioactive copper(II) complexes with polysaccharides, like pullulan and dextran, are important in both veterinary and human medicine for the treatment of hypochromic microcitary anemia and hypocupremia. In aqueous alkaline solutions, Cu(II) ion forms complexes with the exopolysaccharide pullulan and its reduced low-molecular derivative. The metal content and the solution composition depend on pH, temperature, and time of the reaction. The complexing process begins in a weak alkali solution (pH >7) and involves OH groups of pullulan monomer (glucopyranose) units. Complexes of Cu(II) ion with reduced low-molecular pullulan (RLMP, M(w) 6000 g mol(-1)) were synthesized in water solutions, at the boiling temperature and at different pH values ranging from 7.5 to 12. The Cu(II) complex formation with RLMP was analyzed by UV-vis spectrophotometry and other physicochemical methods. Spectroscopic characterizations (ATR-FTIR, FT-IRIS, and EPR) and spectra-structure correlation of Cu(II)-RLMP complexes were also carried out.

  15. New water-soluble copper (II) complexes including 4,7-dimethyl-1,10-phenanthroline and L-tyrosine: synthesis, characterization, DNA interactions and cytotoxicities.

    Science.gov (United States)

    İnci, Duygu; Aydın, Rahmiye; Yılmaz, Dilek; Gençkal, Hasene Mutlu; Vatan, Özgür; Çinkılıç, Nilüfer; Zorlu, Yunus

    2015-02-05

    Two new water-soluble copper(II) complexes, [Cu(dmphen)2(NO3)]NO3 (1), [Cu(dmphen)(tyr)(H2O)]NO3·H2O (2) and the diquarternary salt of dmphen (dmphen = 4,7-dimethyl-1,10-phenanthroline and tyr = L-tyrosine), have been synthesized and characterized by elemental analysis, (1)H NMR, (13)C NMR and IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The CT-DNA binding properties of these compounds have been investigated by absorption, emission spectroscopy and thermal denaturation measurements. The supercoiled pBR322 plasmid DNA cleavage activity of these compounds has been explored by agarose gel electrophoresis. The cytotoxicity of these compounds against MCF-7, Caco-2, A549 cancer cells and BEAS-2B healthy cells was also studied by the XTT method. Complexes 1 and 2 exhibit significant cytotoxicity, with lower IC50 values than those of cisplatin.

  16. Synthesis, characterization, thermal behavior, and DNA-cleaving studies of cyano-bridged nickel(II)-copper(II) complexes of 4-(pyridin-2-ylazenyl)resorcinol.

    Science.gov (United States)

    Karipcin, Fatma; Ozmen, Ismail; Cülü, Burcin; Celikoğlu, Umut

    2011-10-01

    We present here the syntheses of a mononuclear Cu(II) complex and two polynuclear Cu(II)-Ni(II) complexes of the azenyl ligand, 4-(pyridin-2-ylazenyl)resorcinol (HL; 1). The reaction of HL (1) and copper(II) perchlorate with KCN gave a mononuclear complex [CuL(CN)] (4). Using 4, one pentanuclear complex, [{CuL(NC)}(4) Ni](ClO(4))(2) (5) and one trinuclear complex, [{CuL(CN)}(2) NiL]ClO(4) (6), were prepared and characterized by elemental analyses, magnetic susceptibility, molar conductance, IR, and thermal analysis. Stoichiometric and spectral results of the mononuclear Cu(II) complex indicated that the metal/ligand/CN ratio was 1 : 1 : 1, and the ligand behaved as a tridentate ligand forming neutral metal chelates through the pyridinyl and azenyl N-, and resorcinol O-atom. The interaction between the compounds (the ligand 1, its Ni(II) and Cu(II) complexes without CN, i.e., 2 and 3, and its complexes with CN, 4-6) and DNA has also been investigated by agarose gel electrophoresis. The pentanuclear Cu(4) Ni complex (5) with H(2) O(2) as a co-oxidant exhibited the strongest DNA-cleaving activity.

  17. Synthesis, characterization, spectroscopic and theoretical studies of new zinc(II), copper(II) and nickel(II) complexes based on imine ligand containing 2-aminothiophenol moiety

    Science.gov (United States)

    Shafaatian, Bita; Mousavi, S. Sedighe; Afshari, Sadegh

    2016-11-01

    New dimer complexes of zinc(II), copper(II) and nickel(II) were synthesized using the Schiff base ligand which was formed by the condensation of 2-aminothiophenol and 2-hydroxy-5-methyl benzaldehyde. This tridentate Schiff base ligand was coordinated to the metal ions through the NSO donor atoms. In order to prevent the oxidation of the thiole group during the formation of Schiff base and its complexes, all of the reactions were carried out under an inert atmosphere of argon. The X-ray structure of the Schiff base ligand showed that in the crystalline form the SH groups were oxidized to produce a disulfide Schiff base as a new double Schiff base ligand. The molar conductivity values of the complexes in dichloromethane implied the presence of non-electrolyte species. The fluorescence properties of the Schiff base ligand and its complexes were also studied in dichloromethane. The products were characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis, and conductometry. The crystal structure of the double Schiff base was determined by single crystal X-ray diffraction. Furthermore, the density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d,p) level of theory for the determination of the optimized structures of Schiff base complexes.

  18. A new ternary copper(II) complex derived from 2-(2'-pyridyl)benzimidazole and glycylglycine: synthesis, characterization, DNA binding and cleavage, antioxidation and HSA interaction.

    Science.gov (United States)

    Fu, Xia-Bing; Lin, Zi-Hua; Liu, Hai-Feng; Le, Xue-Yi

    2014-03-25

    A new ternary copper(II)-dipeptide complex [Cu(glygly)(HPB)(Cl)]⋅2H2O (glygly=glycylglycine anion, HPB=2-(2'-pyridyl)benzimidazole) has been synthesized and characterized. The DNA interaction of the complex was studied by spectroscopic methods, viscosity, and electrophoresis measurements. The antioxidant activity was also investigated using the pyrogallol autoxidation assay. Besides, the interaction of the complex with human serum albumin (HSA) in vitro was examined by multispectroscopic techniques. The complex partially intercalated to CT-DNA with a high binding constant (Kb=7.28×10(5) M(-1)), and cleaved pBR322 DNA efficiently via an oxidative mechanism in the presence of Vc, with the HO· and O2(-) as the active species, and the SOD as a promoter. Furthermore, the complex shows a considerable SOD-like activity with the IC50 value of 3.8386 μM. The complex exhibits desired binding affinity to HSA, in which hydrogen bond or vander Waals force played a major role. The alterations of HSA secondary structure induced by the complex were confirmed by UV-visible, CD, synchronous fluorescence and 3D fluorescence spectroscopy.

  19. Synthesis and characterization of bis (acetylacetonato κ-O, O') [zinc(ii)/copper(ii)] hybrid organic-inorganic complexes as solid metal organic precursors.

    Science.gov (United States)

    Rooydell, Reza; Wang, Ruey-Chi; Brahma, Sanjaya; Ebrahimzadeh, Farzaneh; Liu, Chuan-Pu

    2015-05-07

    We have synthesized novel metal organic hybrid mixed compounds of bis (acetylacetonato κ-O, O') [zinc(ii)/copper(ii)]. Taking C10H14O4Zn0.7Cu0.3 (Z0.7C0.3AA) as an example, the crystals are composed of Z0.7C0.3AA units and uncoordinated water molecules. Single-crystal X-ray diffraction results show that the complex Z0.7C0.3AA crystallizes in the monoclinic system, space group P21/n. The unit cell dimensions are a = 10.329(4) Å, b = 4.6947(18) Å, and c = 11.369(4) Å; the angles are α = 90°, β = 91.881(6)°, and γ = 90°, the volume is 551.0(4) Å(3), and Z = 2. In this process, the M(ii) ions of Zn and Cu mix and occupy the centers of symmetrical structural units, which are coordinated to two ligands. The measured bond lengths and angles of O-M-O vary with the ratio of metal species over the entire series of the complexes synthesized. The chemistry of the as-synthesized compounds has been characterized using infrared spectroscopy, mass spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analysis, and the morphology of the products has been characterized using scanning electron microscopy. The thermal decomposition of the Z0.7C0.3AA composites measured by thermogravimetric analysis suggests that these complexes are volatile. The thermal characteristics of these complexes make them attractive precursors for metal organic chemical vapor deposition.

  20. New hybrid nanocomposite of copper terephthalate MOF-graphene oxide: synthesis, characterization and application as adsorbents for toxic metal ion removal from Sungun acid mine drainage.

    Science.gov (United States)

    Rahimi, Esmaeil; Mohaghegh, Neda

    2017-08-11

    The application of a hybrid Cu(tpa).GO (Cu(tpa) copper terephthalate metal organic framework, GO graphene oxide) composite as a new adsorbent for the removal of toxic metal ions was reported. New hybrid nanocomposite with excellent dispersibility and stability was successfully fabricated by the simple and effective ultrasonication method. The synthesized composite was characterized by scanning electron microscopy (SEM), UV-Vis and Fourier-transform infrared (FT-IR) techniques. The characterization results concluded that the binding mechanism of the Cu(tpa) and GO was related to both π-π packing and hydrogen bonding. For scrutinizing the sorption activity, the prepared adsorbents were assessed for the removal of Mn(2+), Cu(2+), Zn(2+), Cd(2+), Pb(2+) and Fe(3+) metal ions from aqueous synthetic solution and also acid mine drainage (AMD) wastewater. The sorption experiments demonstrated that the removal efficiency was significantly improved by modified hybrid Cu(tpa).GO composite, owing to the significant number of active binding sites and unique structure formed based on π-conjugated networks. Also, it was shown that the adsorption reaction was mainly attributed to the chemical interactions between metal ions and the surface functional groups. Moreover, kinetic and adsorption studies clarified that the adsorption process onto the Cu(tpa).GO follows a pseudo-second-order kinetics and fits the Langmuir and Freundlich adsorption models. Holistically, the results of this research represent that applying Cu(tpa).GO can be remarked as an effective adsorbent with high possibility at conventional water treatment.

  1. Synthesis, characterization, and spectroscopic investigation of new iron(III) and copper(II) complexes of a carboxylate rich ligand and their interaction with carbohydrates in aqueous solution.

    Science.gov (United States)

    Stewart, Christopher D; Arman, Hadi; Bawazir, Huda; Musie, Ghezai T

    2014-10-20

    New tetra-iron(III) (K4[1]·25H2O·(CH3)2CO and K3[2]·3H2O·(OH)) and di-copper(II) (Na3[3]·5H2O) complexes as carbohydrate binding models have been synthesized and fully characterized used several techniques including single crystal X-ray crystallography. Whereas K4[1]·25H2O·(CH3)2CO and Na3[3]·5H2O are completely water-soluble, K3[2]·3H2O·(OH) is less soluble in all common solvents including water. The binding of substrates, such as d-mannose, d-glucose, d-xylose, and xylitol with the water-soluble complexes in different reaction conditions were investigated. In aqueous alkaline media, complexes K4[1]·25H2O·(CH3)2CO and Na3[3]·5H2O showed coordination ability toward the applied substrates. Even in the presence of stoichiometric excess of the substrates, the complexes form only 1:1 (complex/substrate) molar ratio species in solution. Apparent binding constants, pKapp, values between the complexes and the substrates were determined and specific mode of substrate binding is proposed. The pKapp values showed that d-mannose coordinates strongest to K4[1]·25H2O·(CH3)2CO and Na3[3]·5H2O. Syntheses, characterizations and detailed substrate binding study using spectroscopic techniques and single crystal X-ray diffraction are reported.

  2. Synthesis, spectroscopic characterization and antimicrobial activity of binuclear metal complexes of a new asymmetrical Schiff base ligand: DNA binding affinity of copper(II) complexes.

    Science.gov (United States)

    Shebl, Magdy

    2014-01-03

    The 1:1 condensation of o-acetoacetylphenol and 1,2-diaminopropane under condition of high dilution gives the mono-condensed Schiff base, (E)-3-(1-aminopropan-2-ylimino)-1-(2-hydroxyphenyl)butan-1-one. The mono-condensed Schiff base has been used for further condensation with isatin to obtain the new asymmetrical dicompartmental Schiff base ligand, (E)-3-(2-((E)-4-(2-hydroxyphenyl)-4-oxobutan-2-ylideneamino) propylimino)indolin-2-one (H3L) with a N2O3 donor set. Reactions of the ligand with metal salts give a series of new binuclear complexes. The ligand and its metal complexes were characterized by elemental analyses, IR, (1)H and (13)C NMR, electronic, ESR and mass spectra, conductivity and magnetic susceptibility measurements as well as thermal analyses. The analytical and spectroscopic tools showed that the complexes can be formulated as: [(HL)(VO)2(SO4)(H2O)]·4H2O, [(HL)Fe2Cl4(H2O)3]·EtOH, [(HL)Fe2(ox)Cl2(H2O)3]·2H2O, [(L)M2(OAc)(H2O)m]·nH2O; M=Co, Ni or Cu, m=4, 0 and n=2, 3, [(HL)Cu2Cl]Cl·6H2O and [(L)(UO2)2(OAc)(H2O)3]·6H2O. The metal complexes exhibited octahedral geometrical arrangements except copper complexes that exhibited tetrahedral geometries and uranyl complex in which the metal ion is octa-coordinated. The Schiff base and its metal complexes were evaluated for antimicrobial activity against Gram positive bacteria (Staphylococcus aureus), Gram negative bacteria (Escherichia coli) and fungi (Candida albicans and Aspergillus flavus). The ligand and some of its complexes were found to be biologically active. The DNA-binding properties of the copper complexes (6 and 7) have been investigated by electronic absorption, fluorescence and viscosity measurements. The results obtained indicate that these complexes bind to DNA via an intercalation binding mode with an intrinsic binding constant, Kb of 1.34×10(4) and 2.5×10(4) M(-1), respectively.

  3. Deformation Characterization of Friction-Stir-Welded Tubes by Hydraulic Bulge Testing

    Science.gov (United States)

    Pang, Q.; Hu, Z. L.; Pan, X.; Zuo, X. Q.

    2014-10-01

    In this article, the large-diameter thin-walled aluminum alloy tubes were produced using a hybrid process combining friction-stir welding (FSW) and spinning. For this novel process, rolled aluminum alloy sheets with a thickness about 2-3 times the wall thickness of target tube, were FSW to form cylinders, and then the cylinders were subjected to spinning to get thin-walled aluminum alloy tubes. Both experimental and simulation study were conducted to investigate the deformation characterization of the FSW tube during hydraulic bulge testing, and the stress and strain states and thickness distribution of the FSW tube were investigated. It was found that the common defects of FSW tube can be significantly improved by specific welding devices. The ductility of the tube is considerably improved with nearly two times higher bulge ratio than as-spun tube after annealing treatment at 300°C. But the annealed tube still shows a high nonuniform wall thickness distribution due to the inhomogeneous deformation characteristics. With increasing deformation of the tube, the gap between the hoop and axial stress for the weld and base metal (BM) decreases. However, the hoop and axial stress of the weld are always greater than those of the BM at the same pressure.

  4. Synthesis, characterization and extraction studies of N,N"-bis[1-biphenyl-2-hydroxyimino-2-(4-acetylanilino)-1-ethylidene]-diamines and their homo-and heteronuclear copper(II) complexes

    Indian Academy of Sciences (India)

    Bülent Dede; Fatma Kari̇pci̇n; Mustafa Cengi̇z

    2009-03-01

    A new series of homo- and heteropolynuclear copper(II) complexes of N,N"-bis[1-biphenyl-2-hydroxyimino-2-(4-acetylanilino)-1-ethylidene]-diamines have been prepared and characterized by different physical techniques. The starting point of the research was the reaction of chloroacetyl chloride with biphenyl in the presence of aluminum chloride. 4-Biphenylhydroximoyl chloride was obtained by reacting synthesized 4-(chloroacetyl)biphenyl with alkyl nitrite. Substituted 4-(alkylaminoisonitrosoacetyl) biphenyl (ketooxime) was prepared by reacting 4-biphenylhydroximoyl chloride with 4-aminoacetophenone in EtOH. Homodi-, homotrinuclear and heterodinuclear copper(II) perchlorate complexes of tetradentate Schiff bases which possess N4 donor sets derived from the condensation of 4-(arylaminoisonitrosoacetyl)biphenyl and diamine derivatives were synthesized and characterized. Elemental analysis, FT-IR, ESR, molar conductivity, magnetic moment measurements and thermal analyses studies were utilized for the investigation of the complexes. The free ligands were also characterized by 1H- and 13C-NMR spectra. Elemental analyses, stoichiometric and spectroscopic data of the metal complexes indicated that the metal:ligand ratio of dinuclear copper(II) complexes were found to be 2 : 1 while this ratio was 3 : 2 in trinuclear copper(II) complexes and the metal complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms. The extraction abilities of the novel ligands were also evaluated in chloroform by using several transition metal picrates such as Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+, Hg2+. It has been observed that both ligands show a high affinity to Cu2+ ions.

  5. Syntheses, characterizations and structures of NO donor Schiff base ligands and nickel(II) and copper(II) complexes

    Science.gov (United States)

    Şenol, Cemal; Hayvali, Zeliha; Dal, Hakan; Hökelek, Tuncer

    2011-06-01

    New Schiff base derivatives ( L 1 and L 2) were prepared by the condensation of 2-hydroxy-3-methoxybenzaldehyde ( o-vanillin) and 3-hydroxy-4-methoxybenzaldehyde ( iso-vanillin) with 5-methylfurfurylamine. Two new complexes [Ni(L 1) 2] and [Cu(L 1) 2] have been synthesized with bidentate NO donor Schiff base ligand ( L 1). The Ni(II) and Cu(II) atoms in each complex are four coordinated in a square planar geometry. Schiff bases ( L 1 and L 2) and complexes [Ni(L 1) 2] and [Cu(L 1) 2] were characterized by elemental analyses, FT-IR, UV-vis, mass and 1H, 13C NMR spectroscopies. The crystal structures of the ligand ( L 2) and complexes [Ni(L 1) 2] and [Cu(L 1) 2] have also been determined by using X-ray crystallographic technique.

  6. Synthesis, characterization of new copper (ii) Schiff base and 1,10 phenanthroline complexes and study of their bioproperties.

    Science.gov (United States)

    Reddy, Pulimamidi Rabindra; Rajeshwar, Suryam; Satyanarayana, Battu

    2016-07-01

    Three mononuclear Cu(II) complexes [Cu(naph-phe)phen] (1), [Cu(naph-tyr)(phen)] (2) and [Cu(naph-trp)(phen)] (3) were synthesized, characterized and their biological properties were studied. Complexes 1, 2, 3 exhibit square pyramidal geometry where Schiff base acts as a binegative tridentate ONO donor ligand and phen acts as NN donor ligand. CT-DNA binding studies revealed that the complexes bind through intercalative mode and show good binding propensity. The hydrolytic DNA cleavage activity of these complexes has been studied using gel electrophoresis. The DNA binding and cleavage affinities decrease in the order of 3>2>1. The in-vitro antimicrobial activities of the complexes were also studied.

  7. Copper(ii) complexes of macrocyclic and open-chain pseudopeptidic ligands: synthesis, characterization and interaction with dicarboxylates.

    Science.gov (United States)

    Faggi, Enrico; Gavara, Raquel; Bolte, Michael; Fajarí, Lluís; Juliá, Luís; Rodríguez, Laura; Alfonso, Ignacio

    2015-07-28

    Mono- and dinuclear Cu(ii) complexes were prepared with pseudopeptidic open chain and macrocyclic ligands, respectively. They were characterized by UV-vis spectroscopy, EPR, HRMS and X-ray diffraction. The Cu(ii) cation is coordinated by two amines and two deprotonated amides, in a slightly distorted square planar coordination geometry. The complexes interact with several substituted dicarboxylates, as shown by UV-vis titrations and EPR experiments. The interaction of both mono- and dinuclear complexes with very similar dicarboxylates of biological interest (malate and aspartate) resulted in strikingly different outcomes: in the first case a ternary complex [ligand...metal...dicarboxylate] was obtained almost quantitatively, while in the latter, the Cu(ii) displacement to form Cu(Asp)2 was predominant.

  8. 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...

  9. Hydrothermal Synthesis, Crystal Structure and Spectral Characterization of a New Copper Isopolytungstate: [Cu(phen)3][W6O19

    Institute of Scientific and Technical Information of China (English)

    MENG Fan-Xia; LIU Kun; CHEN Ya-Guang

    2006-01-01

    An unusual inorganic-organic hybrid hexatungstate complex [Cu(phen)3][W6O19] 1(C36H24 CuN6O19W6, Mr= 2011.20) was hydrothermally synthesized and characterized by singlecrystal X-ray diffraction, IR spectrum, UV-VIS spectrum and elemental analyses. This compound crystallizes in the monoclinic system, space group C2/c with a = 19.1005(11), b = 11.2585(11), c =20.2867(15) (A),β= 102.177(2)°, V= 4264.4 (A)3, μ(MoKa) = 16.691 mm-1, Dc = 3.133 g/cm3, Z= 4,F(000) = 3628, the final R = 0.0338 and wR = 0.0798 for 4090 observed reflections with 1 > 2σ(Ⅰ).The result of structure determination shows that the crystal structure is constructed from [W6O19]2-cluster anions and [Cu(phen)3]2+ complex fragments, which are held together into a three-dimensional network through hydrogen-bonding interactions.

  10. Intensely luminescent alkynyl-phosphine gold(I)-copper(I) complexes: synthesis, characterization, photophysical, and computational studies.

    Science.gov (United States)

    Koshevoy, Igor O; Lin, Yi-Chih; Karttunen, Antti J; Chou, Pi-Tai; Vainiotalo, Pirjo; Tunik, Sergey P; Haukka, Matti; Pakkanen, Tapani A

    2009-03-02

    The reactions between the diphosphino-alkynyl gold complexes (XC6H4C2Au)PR2-C6H4-PR2(AuC2C6H4X) with Cu+ lead to the formation of a family of heterometallic clusters of the general formula [{Au3Cu2(C2C6H4X)6}Au3(PR2C6H4PR2)3][PF6]2 (X = NO2, H, OMe, NMe2; R = C6H5, NC4H4). These complexes adopt the same structural pattern and consist of a heterometallic alkynyl cluster [Au3Cu2(C2C6H4X)6]- "wrapped" by the cationic [Au3(PR2C6H4PR2)3]3+ "belt". The novel compounds were characterized by NMR spectroscopy and ESI-MS measurements. A systematic study of their luminescence properties revealed efficient room-temperature phosphorescence in solution with remarkably weak quenching by molecular oxygen. The photophysical experiments demonstrate that the increase in the electron donor ability of the alkynyl ligands and the electron-withdrawing character of the diphosphines results in the bathochromic shift of emission maxima (in the 576-686 nm range) and a decrease in the luminescence quantum yield. The electronic structure calculations showed that variations of X or R substituents have very little effect on the structural parameters but display a significant influence on the electronic properties of the clusters and characteristics of luminescence. The metal-centered triplet emission within the heterometallic alkynyl cluster is suggested to play a key role in the observed phosphorescence.

  11. Synthesis, characterization and catalytic activity of copper(II) complexes containing a redox-active benzoxazole iminosemiquinone ligand.

    Science.gov (United States)

    Balaghi, S Esmael; Safaei, Elham; Chiang, Linus; Wong, Edwin W Y; Savard, Didier; Clarke, Ryan M; Storr, Tim

    2013-05-21

    A tridentate benzoxazole-containing aminophenol ligand HL(BAP) was synthesized and complexed with Cu(II). The resulting Cu(II) complexes were characterized by X-ray, IR, UV-vis-NIR spectroscopies, and magnetic susceptibility studies, demonstrating that the ligand is oxidized to the o-iminosemiquinone form [L(BIS)](-) in the isolated complexes. L(BIS)Cu(II)Cl exhibits a distorted tetrahedral geometry, while L(BIS)Cu(II)OAc is square pyramidal. In both solid state structures the ligand is coordinated to Cu(II)via the benzoxazole, as well as the nitrogen and oxygen atoms from the o-iminosemiquinone moiety. The chloride, or acetate group occupies the fourth and/or fifth positions in L(BIS)Cu(II)Cl and L(BIS)Cu(II)OAc, respectively. Magnetic susceptibility measurements indicate that both complexes are diamagnetic due to antiferromagnetic coupling between the d(9) Cu(II) centre and iminosemiquinone ligand radical. Electrochemical studies of the complexes demonstrate both a quasi-reversible reduction and oxidation process for the Cu complexes. While L(BIS)Cu(II)X (X = Cl) is EPR-silent, chemical oxidation affords a species with an EPR signal consistent with ligand oxidation to form a d(9) Cu(II) iminoquinone species. In addition, chemical reduction results in a Cu(II) centre most likely bound to an amidophenoxide. Mild and efficient oxidation of alcohol substrates to the corresponding aldehydes was achieved with molecular oxygen as the oxidant and L(BIS)Cu(II)X-Cs2CO3 as the catalyst.

  12. Synthesis, characterization, and catalytic properties of cationic hydrogels containing copper(II) and cobalt(II) ions.

    Science.gov (United States)

    Lombardo Lupano, Lucía Victoria; Lázaro Martínez, Juan Manuel; Piehl, Lidia Leonor; Rubín de Celis, Emilio; Torres Sánchez, Rosa María; Campo Dall' Orto, Viviana

    2014-03-18

    Here, we report the synthesis and characterization of a hydrogel based on ethylene glycol diglycidyl ether (EGDE) and 1,8-diamino-3,6-dioxaoctane (DA). Chemically stable Co(II) and Cu(II) coordination complexes were prepared with this nonsoluble polyelectrolyte, poly(EGDE-DA), and studied by ss-NMR, FT-IR, thermogravimetry, and microscopy. Mesopores were found in all the samples, the thermal stability of the polymer matrix was highly affected by the presence of metal ions, and the (13)C CP-MAS spectrum for the Cu(II)-complex evidenced a significant increase in the reticulation degree by Cu(II) ions. The catalytic activity of these materials on H2O2 activation was studied by electron spin resonance (ESR). The Co(II)-poly(EGDE-DA)/H2O2 heterogeneous system produced O2, an anion superoxide (O2(•)¯), and a hydroxyl radical (OH(•)), which diffused into the solution at the time that a decrease in pH was detected. In the same way, the Cu(II)-poly(EGDE-DA)/H2O2 heterogeneous system produced O2 and OH(•). H2O2 activation by the poly(EGDE-DA) complexes with Co(II) and Cu(II) were applied on the decolorization of solutions of the azo-dye methyl orange (MO). In the presence of 63 mM H2O2, 87% of MO was removed in 10 min with Cu(II)-poly(EGDE-DA) and in 110 min with Co(II)-poly(EGDE-DA). In addition, the pharmaceutical product epinephrine was partially oxidized to adrenochrome by the O2(•)¯ released from the Co(II)-poly(EGDE-DA)/H2O2 heterogeneous system.

  13. Preparation and characterization of zinc and copper co-doped WO3 nanoparticles: Application in photocatalysis and photobiology.

    Science.gov (United States)

    Mohammadi, Sanaz; Sohrabi, Maryam; Golikand, Ahmad Nozad; Fakhri, Ali

    2016-08-01

    In this study, pure, Zn, Cu, Zn,Cu co-doped WO3 nanoparticles samples were prepared by precipitation and co-precipitation methods. These nanoparticles were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDX), Dynamic light scattering (DLS), UV-visible and photoluminescence (PL) spectroscopy. The synthesized pure, Zn, Cu, Zn,Cu co-doped WO3 nanoparticles have smart optical properties and average sizes with 3.2, 3.12, 3.08 and 2.97eV of band-gap, 18.1, 23.2, 25.7 and 30.2nm, respectively. Photocatalytic activity of four nanoparticles was studying towards degradation of gentamicin antibiotic under ultraviolet and visible light irradiation. The result showed that Zn,Cu co-doped WO3 possessed high photocatalytic activity. The photocatalytic activity of WO3 nanoparticles could be remarkably increased by doping the Zn and Cu impurity. This can be attributed to the fact that the red shift of absorption edge and the trapping effect of the mono and co-doped WO3 nanoparticles. The research result presents a general and effective way to prepare different photocatalysts with enhanced visible and UV light-driven photocatalytic performance. Antibacterial activity of four different WO3 nanoparticles against Escherichia coli bacterium has been assessed by the agar disc method under light irradiation and dark medium. It is concluded from the present findings that WO3 nanoparticles can be used as an efficient antibacterial agent.

  14. Synthesis and characterization of novel ion-imprinted polymeric nanoparticles for very fast and highly selective recognition of copper(II) ions.

    Science.gov (United States)

    Shamsipur, Mojtaba; Besharati-Seidani, Abbas; Fasihi, Javad; Sharghi, Hashem

    2010-12-15

    This work reports the preparation of new Cu(2+) ion-imprinted polymeric nanoparticles using 1-hydroxy-4-(prop-2'-enyloxy)-9,10-anthraquinone (AQ) as a vinylated chelating agent. The Cu(2+) ion found to form a stable 1:1 complex with AQ in methanol solution. The resulting Cu(2+)-AQ complex was copolymerized with ethyleneglycol dimethacrylate, as a cross-linking monomer, via precipitation polymerization method. The imprint copper ion was removed from the polymeric matrix using a 0.1 mol L(-1) HNO(3) solution. The Cu(2+)-imprinted polymeric nanoparticles were characterized by IR spectroscopy, scanning electron microscopy (SEM) and N(2) adsorption-desorption isotherms. The SEM micrographs showed colloidal nanoparticles of 60-100 nm in diameter and slightly irregular in shape. Optimum pH for maximum sorption was 7.0. Sorption and desorption of Cu(2+) ion on the IIP nanoparticles were quite fast and achieved completely over entire investigated time periods of 2-30 min. Maximum sorbent capacity and enrichment factor of the prepared IIP for Cu(2+) were 73.8 μmol g(-1) and 56.5, respectively. The relative standard deviation and limit of detection (C(LOD)=3S(b)/m) of the method were evaluated as 2.6% and 0.1 ng mL(-1), using inductively coupled plasma-atomic emission spectrometry, respectively. It was found that the imprinting technology results in increased affinity of the prepared material toward Cu(2+) ion over other metal ions with the same charge and close ionic radius. The relative standard deviations for six and twenty replicates with the same nanoparticles were found to be 1.7% and 2.1%, respectively. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Sonochemical Synthesis and Characterization of the Copper(II) Nanocomplex: DNA- and BSA-Binding, Cell Imaging, and Cytotoxicity Against the Human Carcinoma Cell Lines.

    Science.gov (United States)

    Anjomshoa, Marzieh; Torkzadeh-Mahani, Masoud; Dashtrazmi, Ebrahim; Adeli-Sardou, Mahboubeh

    2016-03-01

    The focus of the present work is the preparation of new metal-based nanodrug to overcome limitations of chemotherapy such as poor water solubility of most common chemotherapeutic drugs. The copper(II) complex of 1,2,4-triazine derivatives, [Cu(dppt)2(H2O)2](2+) (dppt is 5,6-diphenyl- 3- (2-pyridyl)-1,2,4-triazine), has been synthesized at nano-size by sonochemical method and characterized by FTIR, zetasizer, and scanning electron microscopy (SEM). The interaction of the complex and nanocomplex with fish sperm DNA (FS-DNA) and BSA have been investigated under physiological conditions by a series of experimental methods. The results have indicated that the complex binds to FS-DNA by two biding modes, viz., electrostatic and intercalates into the base pairs of DNA. The competitive study with ethidium bromide (EB) shows that the complex and nanocomplex competes for the DNA-binding sites with EB. Protein binding studies show that the complex and nanocomplex could bind with BSA. The results of synchronous fluorescence of BSA show that additions of the complex affect the microenvironment of both tyrosine and tryptophan residues during the binding process. The in vitro cytotoxicity of the complex (solution in DMSO) and nanocomplex (colloid in H2O) against the human carcinoma cell lines (MCF-7 and A-549) was evaluated by MTT assay. The results of in vitro cytotoxicity indicate that the complex and nanocomplex have excellent cytotoxicity activity against MCF-7 and A-549. Results of the microscopic analyses of the cancer cells confirm the results of the cytotoxicity.

  16. Bioinspired green synthesis of copper oxide nanoparticles from Syzygium alternifolium (Wt.) Walp: characterization and evaluation of its synergistic antimicrobial and anticancer activity

    Science.gov (United States)

    Yugandhar, Pulicherla; Vasavi, Thirumalanadhuni; Uma Maheswari Devi, Palempalli; Savithramma, Nataru

    2017-08-01

    In recent times, nanoparticles are attributed to green nanotechnology methods to know the synergistic biological activities. To accomplish this phenomenon, present study was aimed to synthesize copper oxide nanoparticles (CuO NPs) by using Syzygium alternifolium stem bark, characterized those NPs using expository tools and to elucidate high prioritized antimicrobial and anticancer activities. Synthesized particles exhibited a color change pattern upon synthesis and affirmed its respective broad peak at 285 nm which was analyzed through UV-vis spectroscopy. FT-IR study confirmed that phenols and primary amines were mainly involved in capping and stabilization of nanoparticles. DLS and Zeta potential studies revealed narrow size of particles with greater stability. XRD studies revealed the crystallographic nature of particles with 17.2 nm average size. Microscopic analysis by using TEM revealed that particle size range from 5-13 nm and most of them were spherical in shape, non-agglomerated and poly-dispersed in condition. Antimicrobial studies of particles showed highest inhibitory activity against E. coli and T. harzianum among bacterial and fungal strains, respectively. The scope of this study is extended by examining anticancer activity of CuO NPs. This study exhibited potential anticancer activity towards MDA-MB-231 human breast cancer lines. Overall, these examinations relate that the S. alternifolium is described as efficient well-being plant and probabilistically for the design and synthesis of nanoparticles for human health. This study paves a way to better understand antimicrobial and anticancer therapeutic drug potentials of nanoparticles to design and analysis of pharmaceuticals by in vivo and in vitro approaches.

  17. Structural, molecular orbital and optical characterizations of binuclear mixed ligand copper (II) complex of phthalate with N,N,N‧,N‧-tetramethylethylenediamine and its applications

    Science.gov (United States)

    Taha, A.; Farag, A. A. M.; Ammar, A. H.; Ahmed, H. M.

    2014-09-01

    A new binuclear mixed ligand complex, [Cu2(Phth)(Me4en)2(H2O)2(NO3)2]·H2O (where, Phth = phthalate, and (Me4en) = N,N,N‧,N‧tetramethylethylenediamine) was synthesized and characterized using analytical, spectral, magnetic, molar conductance, thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. The XRD data of Cu(II)-complex was analyzed on the basis of Williamson-Hall (W-H) and compared with TEM results. The results indicate that the complex is well crystalline and correspond to hexagonal crystal structure. Analysis of the absorption coefficient near the absorption edge reveals that the optical band gaps are indirect allowed transition with values of 1.17 and 1.78 eV. The d-d absorption bands of the complex (dissolved in various solvents) exhibit a color changes (solvatochromic). Specific and non-specific interactions of solvent molecules with the complex were investigated using Multiple Linear Regression Analysis (MLRA). Transient photocurrent characteristics of Cu(II)-complex/n-Si heterojunctions indicate that photocurrent under illumination increase with increasing of light intensity and explained by continuous distribution of traps. Structural parameters of the free ligands and their Cu(II) - complex were calculated on the basis of semi-empirical PM3 level and compared with the experimental data. The present copper (II) complex was screened for its antimicrobial activity against some Gram-positive and Gram-negative bacteria and fungus strain.

  18. Structural, molecular orbital and optical characterizations of binuclear mixed ligand copper (II) complex of phthalate with N,N,N',N'-tetramethylethylenediamine and its applications.

    Science.gov (United States)

    Taha, A; Farag, A A M; Ammar, A H; Ahmed, H M

    2014-09-15

    A new binuclear mixed ligand complex, [Cu2(Phth)(Me4en)2(H2O)2(NO3)2]·H2O (where, Phth=phthalate, and (Me4en)=N,N,N',N'tetramethylethylenediamine) was synthesized and characterized using analytical, spectral, magnetic, molar conductance, thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. The XRD data of Cu(II)-complex was analyzed on the basis of Williamson-Hall (W-H) and compared with TEM results. The results indicate that the complex is well crystalline and correspond to hexagonal crystal structure. Analysis of the absorption coefficient near the absorption edge reveals that the optical band gaps are indirect allowed transition with values of 1.17 and 1.78 eV. The d-d absorption bands of the complex (dissolved in various solvents) exhibit a color changes (solvatochromic). Specific and non-specific interactions of solvent molecules with the complex were investigated using Multiple Linear Regression Analysis (MLRA). Transient photocurrent characteristics of Cu(II)-complex/n-Si heterojunctions indicate that photocurrent under illumination increase with increasing of light intensity and explained by continuous distribution of traps. Structural parameters of the free ligands and their Cu(II)-complex were calculated on the basis of semi-empirical PM3 level and compared with the experimental data. The present copper (II) complex was screened for its antimicrobial activity against some Gram-positive and Gram-negative bacteria and fungus strain.

  19. Using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to characterize copper, zinc and mercury along grizzly bear hair providing estimate of diet.

    Science.gov (United States)

    Noël, Marie; Christensen, Jennie R; Spence, Jody; Robbins, Charles T

    2015-10-01

    We enhanced an existing technique, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), to function as a non-lethal tool in the temporal characterization of trace element exposure in wild mammals. Mercury (Hg), copper (Cu), cadmium (Cd), lead (Pb), iron (Fe) and zinc (Zn) were analyzed along the hair of captive and wild grizzly bears (Ursus arctos horribilis). Laser parameters were optimized (consecutive 2000 μm line scans along the middle line of the hair at a speed of 50 μm/s; spot size=30 μm) for consistent ablation of the hair. A pressed pellet of reference material DOLT-2 and sulfur were used as external and internal standards, respectively. Our newly adapted method passed the quality control tests with strong correlations between trace element concentrations obtained using LA-ICP-MS and those obtained with regular solution-ICP-MS (r(2)=0.92, 0.98, 0.63, 0.57, 0.99 and 0.90 for Hg, Fe, Cu, Zn, Cd and Pb, respectively). Cross-correlation analyses revealed good reproducibility between trace element patterns obtained from hair collected from the same bear. One exception was Cd for which external contamination was observed resulting in poor reproducibility. In order to validate the method, we used LA-ICP-MS on the hair of five captive grizzly bears fed known and varying amounts of cutthroat trout over a period of 33 days. Trace element patterns along the hair revealed strong Hg, Cu and Zn signals coinciding with fish consumption. Accordingly, significant correlations between Hg, Cu, and Zn in the hair and Hg, Cu, and Zn intake were evident and we were able to develop accumulation models for each of these elements. While the use of LA-ICP-MS for the monitoring of trace elements in wildlife is in its infancy, this study highlights the robustness and applicability of this newly adapted method.

  20. Non-covalent interactions in 2-methylimidazolium copper(II) complex (MeImH)2[Cu(pfbz)4]: Synthesis, characterization, single crystal X-ray structure and packing analysis

    Science.gov (United States)

    Sharma, Raj Pal; Saini, Anju; Kumar, Santosh; Kumar, Jitendra; Sathishkumar, Ranganathan; Venugopalan, Paloth

    2017-01-01

    A new anionic copper(II) complex, (MeImH)2 [Cu(pfbz)4] (1) where, MeImH = 2-methylimidazolium and pfbz = pentafluorobenzoate has been isolated by reacting copper(II) sulfate pentahydrate, pentafluorobenzoic acid and 2-methylimidazole in ethanol: water mixture in 1:2:2 molar ratio. This complex 1 has been characterized by elemental analysis, thermogravimetric analysis, spectroscopic techniques (UV-Vis, FT-IR) and conductance measurements. The complex salt crystallizes in monoclinic crystal system with space group C2/c. Single crystal X-ray structure determination revealed the presence of discrete ions: [Cu(pfbz)4]2- anion and two 2-methylimidazolium cation (C4H7N2)+. The crystal lattice is stabilized by strong hydrogen bonding and F⋯F interactions between cationic-anionic and the anionic-anionic moieties respectively, besides π-π interactions.

  1. Gas tungsten arc welding and friction stir welding of ultrafine grained AISI 304L stainless steel: Microstructural and mechanical behavior characterization

    Energy Technology Data Exchange (ETDEWEB)

    Sabooni, S., E-mail: s.sabooni@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan (Iran, Islamic Republic of); Karimzadeh, F.; Enayati, M.H. [Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan (Iran, Islamic Republic of); Ngan, A.H.W. [Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Jabbari, H. [Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan (Iran, Islamic Republic of)

    2015-11-15

    In the present study, an ultrafine grained (UFG) AISI 304L stainless steel with the average grain size of 650 nm was successfully welded by both gas tungsten arc welding (GTAW) and friction stir welding (FSW). GTAW was applied without any filler metal. FSW was also performed at a constant rotational speed of 630 rpm and different welding speeds from 20 to 80 mm/min. Microstructural characterization was carried out by High Resolution Scanning Electron Microscopy (HRSEM) with Electron Backscattered Diffraction (EBSD) and Transmission Electron Microscopy (TEM). Nanoindentation, microhardness measurements and tensile tests were also performed to study the mechanical properties of the base metal and weldments. The results showed that the solidification mode in the GTAW welded sample is FA (ferrite–austenite) type with the microstructure consisting of an austenite matrix embedded with lath type and skeletal type ferrite. The nugget zone microstructure in the FSW welded samples consisted of equiaxed dynamically recrystallized austenite grains with some amount of elongated delta ferrite. Sigma phase precipitates were formed in the region ahead the rotating tool during the heating cycle of FSW, which were finally fragmented into nanometric particles and distributed in the weld nugget. Also there is a high possibility that the existing delta ferrite in the microstructure rapidly transforms into sigma phase particles during the short thermal cycle of FSW. These suggest that high strain and deformation during FSW can promote sigma phase formation. The final austenite grain size in the nugget zone was found to decrease with increasing Zener–Hollomon parameter, which was obtained quantitatively by measuring the peak temperature, calculating the strain rate during FSW and exact examination of hot deformation activation energy by considering the actual grain size before the occurrence of dynamic recrystallization. Mechanical properties observations showed that the welding

  2. Characterization and study of pinning properties of bulk neodymium barium copper oxide superconductor with the neutron-induced fission

    Science.gov (United States)

    Osabe, Goro

    This dissertation describes work on characterization of the bulk Nd 1Ba2Cu3Oy high temperature superconductor, and investigation of flux pinning properties of columnar defects. The U/n process has been used to introduce quasi-columnar pinning centers into Nd123. The process involves adding 235U to the precursor powders of the superconductor, texturing, and irradiating with thermal neutrons. The nuclear fission fragments cause discontinuous broken columnar damage which acts as pinning centers. We intensively investigate the pinning properties due to the U/n process. We performed studies of superconductivity characteristics for U/n-Nd123, such as trapped field, critical current Jc, anisotropic, angular dependence of magnetization, flux creep, irreversible field and critical temperature. All measurements were made both before and after irradiation. The U/n process also results in chemical pinning centers smaller than 1mum. Pinning properties due to these chemical pinning centers were also investigated. Our results show that the U/n method increases the trapped field by factor of 4.45 (+/-0.36), and increases J c before 28,097 A/cm2 to values of 160,750 A/cm 2 at 77K with applied field 0.17T. If our best sample had been used at the best fluence, the sample would have reached a trapped field of 2997.9 G (3mm cube) at the peak fluence Fn = 0.885x10 16 n/cm2. A theoretical proposal for the summation problem for columnar pinning is also proposed. We introduce the concept of reduction of the order parameter due to the ion damage. We then have set up the summation problem for columnar defects. We use this approach for the summation problem in order to obtain Jc, as a function of diameter of columnar damage, number of incident ions, and magnetic field. These results have fairly good quantitative agreement with the actual experimental results. The calculations reveal that discontinuous columnar defects yield the maximum Jc in agreement with experiment. The highest Jc can be

  3. Impact of M2-Hss Tool Pin Profile in Fsw Welded Joints On Mechanical Properties Of Aa7075-T6 Aluminium Alloy

    Directory of Open Access Journals (Sweden)

    Venugopal S

    2014-05-01

    Full Text Available Friction stir, “welding is a solid state joining process and is widely being considered for aluminium alloys. The main advantage of FSW is the material that is being welded undergoes only localized changes. The welding parameter and tool pin profile play a major role in deciding the weld quality. In this work an effort has been made to analyze microstructure of aluminium AA 7075-T6 alloy. Three different tool profiles (Taper Threaded, cylindrical and square have been used to construct the joints in particular rotational speed. Tensile, Impact, micro hardness of mechanical properties of the joints have been evaluated and the formation of FSP zone has been analyzed microscopically. From the investigation it is found that the threaded cylindrical profile produces highly (defined Strength in welds.

  4. Efecto del procedimiento de soldadura por FSW en la evolución temporal de las propiedades en uniones de AA 7075-T651

    Directory of Open Access Journals (Sweden)

    Leonardo N. Tufaro

    2014-12-01

    Full Text Available Se estudió el efecto del procedimiento de soldadura sobre la evolución temporal de las propiedades mecánicas de uniones soldadas por fricción-agitación (FSW en chapa de AA7075-T651. A este fin se realizaron soldaduras por FSW bajo distintas condiciones de soldadura (velocidad de rotación y velocidad de avance de modo de variar el aporte térmico. Se registraron los ciclos térmicos mediante la instrumentación de termocuplas y se determinó el aporte térmico neto en cada caso. Las uniones soldadas fueron caracterizadas macroestructuralmente, se determinaron perfiles de microdureza Vickers y la resistencia a la tracción a distintos tiempos luego de realizada la soldadura, los cuales variaron entre 1 y 900 días. Se observó que la dureza mínima (HVmin se ubicó en la zona afectada térmicamente (HAZ y que la misma aumentó al disminuir el aporte térmico introducido durante la soldadura. Asimismo, dicho valor HVmin aumentó con el tiempo, siguiendo una evolución logarítmica para todas las condiciones de soldadura. Este aumento fue mayor para la probeta soldada con menor aporte térmico. A su vez, la resistencia a la tracción de las uniones soldadas aumentó con el tiempo, evolucionando también en forma logarítmica, alcanzando una eficiencia de junta del 80%.

  5. A novel stress-accurate FE technology for highly non-linear analysis with incompressibility constraint. Application to the numerical simulation of the FSW process

    Science.gov (United States)

    Chiumenti, M.; Cervera, M.; Agelet de Saracibar, C.; Dialami, N.

    2013-05-01

    In this work a novel finite element technology based on a three-field mixed formulation is presented. The Variational Multi Scale (VMS) method is used to circumvent the LBB stability condition allowing the use of linear piece-wise interpolations for displacement, stress and pressure fields, respectively. The result is an enhanced stress field approximation which enables for stress-accurate results in nonlinear computational mechanics. The use of an independent nodal variable for the pressure field allows for an adhoc treatment of the incompressibility constraint. This is a mandatory requirement due to the isochoric nature of the plastic strain in metal forming processes. The highly non-linear stress field typically encountered in the Friction Stir Welding (FSW) process is used as an example to show the performance of this new FE technology. The numerical simulation of the FSW process is tackled by means of an Arbitrary-Lagrangian-Eulerian (ALE) formulation. The computational domain is split into three different zones: the work.piece (defined by a rigid visco-plastic behaviour in the Eulerian framework), the pin (within the Lagrangian framework) and finally the stirzone (ALE formulation). A fully coupled thermo-mechanical analysis is introduced showing the heat fluxes generated by the plastic dissipation in the stir-zone (Sheppard rigid-viscoplastic constitutive model) as well as the frictional dissipation at the contact interface (Norton frictional contact model). Finally, tracers have been implemented to show the material flow around the pin allowing a better understanding of the welding mechanism. Numerical results are compared with experimental evidence.

  6. Avaliação da geometria de ferramenta e parâmetros do processo FSW na soldagem da liga de alumínio AA 5052 Process parameters and tool geometry evaluation in the FSW of AA 5052 aluminum alloy

    OpenAIRE

    2009-01-01

    A soldagem de ligas de alumínio sem degradação excessiva das propriedades originais do metal base apresenta-se como um obstáculo a ser superado pelas indústrias em seus processos de fabricação, uma vez que o alumínio tem sido usado cada vez de forma mais intensiva. Neste sentido, o processo de soldagem denominado Friction Stir Welding (FSW) tem recebido atenção por suas potencialidades onde o aporte de calor deve ser minimizado ou quando metais dissimilares devem ser soldados. Neste processo,...

  7. Preparation and Characterization of Copper/Silver Alloy Nanoparticles%铜/银合金纳米粒子的制备及表征

    Institute of Scientific and Technical Information of China (English)

    张念椿; 胡建强

    2014-01-01

    The preparation method of copper/silver alloy nanoparticles was studied. The small particle size of nano copper was prepared by using the environmentally friendly ascorbic acid as a reducing agent. But this nano copper had poor stability, and is easy to be oxidized. In order to improve its stability, a small amount of Ag+was added during the preparation of nano copper. The silver layer was covered on the nano copper surface by reduction reaction. The copper/silver alloy nanocrystalline possesses good stability and nanoparticles effect. The copper/silver alloy nanoparticles are expected to having potential application in production of printed circuits. The preparation method has shorter product process than the conventional PCB production, thus it can save resources and reduce the environmental pollution.%研究了铜/银合金纳米粒子的制备方法,用抗坏血酸做还原剂,制备了粒径小的纳米铜粉。由于纳米铜粉的稳定性差,易氧化,为了提高其稳定性,在制备的纳米铜粉中加了少量的Ag+,在纳米铜粉表面还原制备出银纳米层覆盖于在铜上。所制备的纳米铜/银合金纳米粒子稳定性好,具有纳米粒子的效应,有望应用于印制电路的制造。该制备方法可以减少传统印制电路板制作方法的工序,节约资源,且减少对环境的污染。

  8. The Frequency of Sexual Intercourse without Condom with Female Sex Workers [FSW] is not Related to the Level of Sexual Satisfaction of the Husband, But Related to the Risk of Sexually Transmitted Infections [STIS

    Directory of Open Access Journals (Sweden)

    Ainun Sajidah

    2015-06-01

    Full Text Available Background: Disharmonious sexual life often create many problems. When the sexual function of the wives is not optimum, the sexual satisfaction of the husbands, or both husband and wife, will be disturbed. These will lead husbands to do sexual intercourses with FSW without condoms. Such intercourse may cause of STIs. The aims of this study were to identify the frequency of sexual intercourse without condom with FSW related to the level of sexual satisfaction of the husband and the risk of STIs. Methods:The study applied observational analytic with cross sectional design. The accidental sampling technique, the 196 samples, comprise of husband with the following criteria: having non-menopause legal wives, regularly having sex with wives without condoms within 6 months, having sex with FSW without condom at least once in 6 months, in the family stage II standard, healthy and willing to be respondents. Data on the level of sexual satisfaction and frequency of sexual intercourse without condom was collected through interviews, data on the risk of STIs was collected with physical and laboratory check-up by medical staff. The laboratory check-up for gonorrhea was done with the Gram’s coloring, syphilis with T. Pallidum Hemagglutination Assay (TPHA and Veneral Disease Research Laboratory (VDRL, genital herpes and acuminate condyloma with clinical symptoms. The result was analysed descriptively and data normality was tested with Kolmogorov-Smirnov test and the correlaton test was done with the Spearman’s rho and Chi-Square tests. Results:The result showed there was the frequency of sexual intercourse without condom with FSW the most 1 time/week 57 persons (29.10%, with STIs 10 persons (5,10% the level of sexual satisfaction that was quite satisfied 97 persons (49.50%, and the STIs 41 persons (20,90%. The frequency of sexual intercourse without condom with FSW not related to the level of sexual satisfaction of the husbands p = 0.146 (p

  9. A versatile and efficient markerless gene disruption system for Acidithiobacillus thiooxidans: application for characterizing a copper tolerance related multicopper oxidase gene.

    Science.gov (United States)

    Wen, Qing; Liu, Xiangmei; Wang, Huiyan; Lin, Jianqun

    2014-11-01

    The acidophilic bioleaching bacteria can usually survive in high concentrations of copper ions because of their special living environment. However, little is known about the copper homeostatic mechanisms of Acidithiobacillus thiooxidans, an important member of bioleaching bacteria. Here, a putative multicopper oxidase gene (cueO) was detected from the draft genome of A. thiooxidans ATCC 19377. The transcriptional level of cueO in response to 10 mM CuSO₄was upregulated 25.01 ± 2.59 folds. The response of P(cueO) to copper was also detected and might be stimulated by a putative CueR protein. Then, by using the counter-selectable marker lacZ and enhancing the expression of endonuclease I-SceI with tac promoter, a modified markerless gene disruption system was developed and the cueO gene disruption mutant (ΔcueO) of A. thiooxidans was successfully constructed with a markedly improved second homologous recombination frequency of 0.28 ± 0.048. The ΔcueO mutant was more sensitive to external copper and nearly completely lost the phenoloxidase activity; however, the activity could be restored after complementing the cueO gene. All results suggest the close relation of cueO gene to copper tolerance in A. thiooxidans. In addition, the developed efficient markerless gene knockout method can also be introduced into other Acidithiobacillus strains.

  10. Copper allergy from dental copper amalgam?

    Science.gov (United States)

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

    2002-05-06

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

  11. A dinuclear end-on azide-bridged copper(II) compound with weak antiferromagnetic interaction - Synthesis, characterization, magnetism and X-ray structure of bis[(μ-azido-κN1)-(azido-κN1)(1,3-bis(benzimidazol-2-yl)-2-methylpropane)copper(II)

    Science.gov (United States)

    van Albada, Gerard A.; Mutikainen, Ilpo; Roubeau, Olivier; Reedijk, Jan

    2013-03-01

    The centrosymmetric dinuclear compound of formula [Cu(μ-N3-κN1)(N3-κN1)(bbmp)]2 is reported. Synthesis, characterization, physical properties are determined in detail, together with its 3D structure. The dinuclear end-on azide-bridged copper(II) compound displays a weak antiferromagnetic interaction, despite the fact that the magnetic orbitals overlap. The Cu-Cu contact distance is 3.1867(8) Å, while the Cu-Nazide-Cu angle is 103.41(14)°. The IR spectra of the azido ligands are as expected for such coordinated azides.

  12. Characterization and Catalytic Activity for the Oxidation of Ethane and Propane on Platinum and Copper Supported on CeO2/Al2O3

    Directory of Open Access Journals (Sweden)

    Cataluña R.

    1998-01-01

    Full Text Available Ethane and propane oxidation on platinum and copper supported on Al2O3 and CeO2/Al2O3 catalysts were studied comparatively by examining reaction rates as a function of temperature. Results show that the addition of cerium oxide shifts the catalytic activity to higher temperatures. This negative influence is less pronounced in the case of supported copper samples, which on the basis of EPR and FTIR of adsorbed CO results is attributed to the low relative amount of this metal is in contact with ceria. The decrease in activity the presence of ceria might be due to changes in metal particle size or to the stabilization of the oxidized states of the metals, induced by their interactions with cerium oxide. The higher activity of platinum, in comparison with copper, is attributed to its higher reducibility along with an easier hydrocarbon activation on that metal.

  13. 1D polymeric copper(I) complex [Cu2(μ-(2,6-Cl-ba)2en)(μ-I)2]n with exceptionally short Cusbnd Cu distance: Synthesis, characterization, thermal study and crystal structure

    Science.gov (United States)

    Khalaji, Aliakbar Dehno; Peyghoun, Seyyed Javad; Akbari, Alireza; Feizi, Nourollah; Dusek, Michal; Eigner, Vaclav

    2017-01-01

    A new 1D polymeric three coordinated copper(I) complex, [Cu2(μ-(2,6-Cl-ba)2en)(μ-I)2]n, with the bidentate Schiff base ligand N,N‧-bis(2,6-dichlorobenzylidene)ethane-1,2-diamine containing a flexible spacer (dbnd NCH2sbnd CH2sbnd Ndbnd) was synthesized and characterized by elemental analyses, UV-Vis, FT-IR and 1H NMR spectroscopy and thermal analaysis. Its molecular structure was determined by single-crystal X-ray diffraction and shows the (2,6-Cl-ba)2en acts as a bis-monodentate bridging ligand forming the dinuclear [Cu2(μ-(2,6-Cl-ba)2en)] groups. Such dinuclear groups are bridged by two iodine anions [(μ-I)2] to form a 1D polymeric copper(I) complex. The copper(I) ions are coordinated in a distorted trigonal planar geometry by two I atoms and one nitrogen atom of Schiff base ligand (2,6-Cl-ba)2en.

  14. Copper Products Capacity Expansion Stimulate the Copper Consumption

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

  15. Trace elements in human physiology and pathology. Copper.

    Science.gov (United States)

    Tapiero, H; Townsend, D M; Tew, K D

    2003-11-01

    Copper is a trace element, important for the function of many cellular enzymes. Copper ions can adopt distinct redox states oxidized Cu(II) or reduced (I), allowing the metal to play a pivotal role in cell physiology as a catalytic cofactor in the redox chemistry of enzymes, mitochondrial respiration, iron absorption, free radical scavenging and elastin cross-linking. If present in excess, free copper ions can cause damage to cellular components and a delicate balance between the uptake and efflux of copper ions determines the amount of cellular copper. In biological systems, copper homeostasis has been characterized at the molecular level. It is coordinated by several proteins such as glutathione, metallothionein, Cu-transporting P-type ATPases, Menkes and Wilson proteins and by cytoplasmic transport proteins called copper chaperones to ensure that it is delivered to specific subcellular compartments and thereby to copper-requiring proteins.

  16. Antwerp Copper Plates

    DEFF Research Database (Denmark)

    Wadum, Jørgen

    1999-01-01

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

  17. Using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to characterize copper, zinc and mercury along grizzly bear hair providing estimate of diet

    Energy Technology Data Exchange (ETDEWEB)

    Noël, Marie, E-mail: marie.noel@stantec.com [Stantec Consulting Ltd. 2042 Mills Road, Unit 11, Sidney BC V8L 4X2 (Canada); Christensen, Jennie R., E-mail: jennie.christensen@stantec.com [Stantec Consulting Ltd. 2042 Mills Road, Unit 11, Sidney BC V8L 4X2 (Canada); Spence, Jody, E-mail: jodys@uvic.ca [School of Earth and Ocean Sciences, Bob Wright Centre A405, University of Victoria, PO BOX 3065 STN CSC, Victoria, BC V8W 3V6 (Canada); Robbins, Charles T., E-mail: ctrobbins@wsu.edu [School of the Environment and School of Biological Sciences, Washington State University, Pullman, WA 99164-4236 (United States)

    2015-10-01

    We enhanced an existing technique, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), to function as a non-lethal tool in the temporal characterization of trace element exposure in wild mammals. Mercury (Hg), copper (Cu), cadmium (Cd), lead (Pb), iron (Fe) and zinc (Zn) were analyzed along the hair of captive and wild grizzly bears (Ursus arctos horribilis). Laser parameters were optimized (consecutive 2000 μm line scans along the middle line of the hair at a speed of 50 μm/s; spot size = 30 μm) for consistent ablation of the hair. A pressed pellet of reference material DOLT-2 and sulfur were used as external and internal standards, respectively. Our newly adapted method passed the quality control tests with strong correlations between trace element concentrations obtained using LA-ICP-MS and those obtained with regular solution-ICP-MS (r{sup 2} = 0.92, 0.98, 0.63, 0.57, 0.99 and 0.90 for Hg, Fe, Cu, Zn, Cd and Pb, respectively). Cross-correlation analyses revealed good reproducibility between trace element patterns obtained from hair collected from the same bear. One exception was Cd for which external contamination was observed resulting in poor reproducibility. In order to validate the method, we used LA-ICP-MS on the hair of five captive grizzly bears fed known and varying amounts of cutthroat trout over a period of 33 days. Trace element patterns along the hair revealed strong Hg, Cu and Zn signals coinciding with fish consumption. Accordingly, significant correlations between Hg, Cu, and Zn in the hair and Hg, Cu, and Zn intake were evident and we were able to develop accumulation models for each of these elements. While the use of LA-ICP-MS for the monitoring of trace elements in wildlife is in its infancy, this study highlights the robustness and applicability of this newly adapted method. - Highlights: • LA-ICP-MS provides temporal trace metal exposure information for wild grizzly bears. • Cu and Zn temporal exposures provide

  18. In situ deposits of copper and copper oxide containing condensation polyimide films

    Science.gov (United States)

    Porta, G. M.; Taylor, L. T.

    1987-01-01

    Novel copper-polyimide composites have been synthesized via simultaneous thermal decomposition of solid solutions of bis (trifluoroacetylacetonato) copper (II) and thermal cyclodehydration of polyimide acid. In contrast to conventional filled polymer composites which are prepared by dispersion of particles or fibers in a polymer matrix this study has yielded in general uniform Cu or CuO dispersions of very small particle size that reside near the film surface that was exposed to the atmosphere during curing. The nature of the copper deposit, the thickness of the copper deposit, and the polyimide overlayer which bonds the copper to the polymer substrate depend on the curing atmosphere used. A variety of analytical surface methods along with thermogravimetric analysis and variable temperature (surface and volume) electrical resistivity measurements have been used to characterize these thin, flexible copper doped polyimide films.

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

    Science.gov (United States)

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

    2014-01-01

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

  20. Comments on the paper: Synthesis growth and characterization of copper mercury thiocyanate crystal [Indian J Pure & App Phys 49 (2011) 340-343

    OpenAIRE

    Srinivasan, Bikshandarkoil R.

    2015-01-01

    The unit cell parameters, infrared and UV-Vis spectral data reported in the paper by Vijayabhaskaran et al (Indian J Pure & App Phys 49 (2011) 340-343) cannot belong to the colourless crystalline compound formulated as copper mercury thiocyanate CuHg(SCN)4 as claimed by the authors.

  1. Synthesis and Characterization of Copper-Based Composites Reinforced by CuZrAlNiTi Amorphous Particles with Enhanced Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Kinga Tomolya

    2017-03-01

    Full Text Available Novel amorphous/crystalline composites were developed combining the ductile copper matrix with hard CuZr-based amorphous powder. The amorphous powders of two compositions, Cu39.2Zr36All4.8Ni10Ti10 and Cu39.2Zr35.2Al5.6Ni10Ti10, produced by ball milling were used for reinforcement of the composites. Different mixing techniques, magnetic mixing, ultrasonic mixing and high-energy ball milling, were applied in order to create a homogenous mixture of the powders. The composites were produced by hot pressing under a purified argon atmosphere. Their microstructure, homogeneity and mechanical properties were investigated. It was observed that before hot pressing, minimal porosity had been obtained for the composite blended for 15 min by the ball-mill with a ball-to-powder ratio of 80:1. Its copper content was 50 wt %, which is the minimum to produce a compact composite. Reinforcing the copper by amorphous powders, the maximal compressive strength was enhanced to 490 MPa and 470 MPa, respectively, for the abovementioned composites. The yield strength of the copper due to reinforcement increased drastically from 150 MPa to 400 MPa and 420 MPa.

  2. The Preparation and Characterization of the Geometric Isomers of a Coordination Complex: cis- and trans-bis Glycinato Copper (II) Monohydrates.

    Science.gov (United States)

    O'Brien, Paul

    1982-01-01

    Preparation of cis and trans isomers of the kinetically labile bis glycinato copper (II) has a number of advantages including its facility, economy, ready theoretical interpretation, and biological relevance. Background information, laboratory procedures, results/discussion are provided for this experiment which can be completed in a single,…

  3. Synthesis and characterization of cyclic polystyrene using copper-catalyzed alkyne-azide cycloaddition coupling - evaluation of physical properties and optimization of cyclization conditions

    Science.gov (United States)

    Elupula, Ravinder

    Polymers with a cyclic topology exhibit a range of unique and potentially useful physical properties, including reduced rates of degradation and increased rates of diffusion in bulk relative to linear analogs. However the synthesis of high purity cyclic polymers, and verification of their structural purity remains challenging. The copper-catalyzed azide-alkyne "click" cyclization route toward cyclic polymers has been used widely, due to its synthetic ease and its compatibility with diverse polymer backbones. Yet unoptimized click cyclization conditions have been observed to generate oligomeric byproducts. In order to optimize these cyclization conditions, and to better understand the structure of the higher molecular weight oligomers, these impurities have been isolated by size exclusion chromatography (SEC) and characterized by mass spectrometry (MS). Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-ToF) MS is a particularly valuable characterization tool and was used to determine that the high molecular weight impurities are predominantly cyclic oligomers. It should also be noted that the rapid analysis and small analyte requirements of this MS technique make it particularly attractive as a general tool for elucidating polymer architecture. Ability to tailor the physical properties of polymers by changing the architecture alone has garnered a lot of attention over the past few decades. Compared to their linear analogues, these novel polymer architectures behave completely different in nanoscale regime. Cyclic polymers are especially intriguing since we can compare the differences in the physical properties with that of the linear chains. One of the major physical property changes are T g-confinement effect. Using ATRP and "click chemistry" we have produced highly pure cyclic PS (c-PS) with number-average molecular weight (MW) of 3.4 kg/mol and 9.1 kg/mol. Bulk glass transition temperatures for c-PS were weakly depended on MWs

  4. Preparation of copper nanofluids using an appropriate technique

    Directory of Open Access Journals (Sweden)

    Hamid Reza Ghorbani

    2014-12-01

    Full Text Available This work focuses on the synthesis of copper nanoparticles. The synthesis involves the use of copper nitrate, polyvinylpyrrolidone (pvp, dextrose and water as the copper precursor, stabilizing agent, reducing agent and solvent respectively.The nanoparticles were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM and dynamic light scattering (DLS. An absorption peak at 580 nm in Uv–Vis spectrophotometer was detected indicating the presence of copper nanoparticles. The DLS analysis showed Copper nanoparticles with size of 5-25 nm.

  5. Metallurgical and chemical characterization of copper alloy reference materials within laser ablation inductively coupled plasma mass spectrometry: Method development for minimally-invasive analysis of ancient bronze objects

    Energy Technology Data Exchange (ETDEWEB)

    Walaszek, Damian, E-mail: damian.walaszek@empa.ch [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); University of Warsaw, Faculty of Chemistry, Pasteura 1, 02-093 Warsaw (Poland); Senn, Marianne [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Faller, Markus [Laboratory for Jointing Technology and Corrosion, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Philippe, Laetitia [Laboratory for Mechanics of Materials and Nanostructures, Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkstrasse 39, CH-3602 Thun (Switzerland); Wagner, Barbara; Bulska, Ewa [University of Warsaw, Faculty of Chemistry, Pasteura 1, 02-093 Warsaw (Poland); Ulrich, Andrea [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland)

    2013-01-01

    The chemical composition of ancient metal objects provides important information for manufacturing studies and authenticity verification of ancient copper or bronze artifacts. Non- or minimal-destructive analytical methods are preferred to mitigate visible damage. Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) enables the determination of major elements as well as impurities down to lower ppm-levels, however, accuracy and precision of analysis strongly depend on the homogeneity of reference materials used for calibration. Moreover, appropriate analytical procedures are required e.g. in terms of ablation strategies (scan mode, spot size, etc.). This study reviews available copper alloy (certified) reference materials — (C)RMs from different sources and contributes new metallurgical data on homogeneity and spatial elemental distribution. Investigations of the standards were performed by optical and scanning electron microscopy with X-ray spectrometry (SEM-EDX) for the following copper alloy and bronze (certified) reference materials: NIST 454, BAM 374, BAM 211, BAM 227, BAM 374, BAM 378, BAS 50.01-2, BAS 50.03-4, and BAS 50.04-4. Additionally, the influence of inhomogeneities on different ablation and calibration strategies is evaluated to define an optimum analytical strategy in terms of line scan versus single spot ablation, variation of spot size, selection of the most appropriate RMs or minimum number of calibration reference materials. - Highlights: ► New metallographic data for copper alloy reference materials are provided. ► Influence of RMs homogeneity on quality of LA-ICPMS analysis was evaluated. ► Ablation and calibration strategies were critically discussed. ► An LA-ICPMS method is proposed for analyzing most typical ancient copper alloys.

  6. Synthesis, Characterization, and Crystal Structure of a Novel Copper(II) Complex with an Asymmetric Coordinated 2,2'-Bipyridine Derivative: A Model for the Associative Complex in the Ligand-Substitution Reactions of [Cu(tren)L](2+)?

    Science.gov (United States)

    Lu Zl, Zhong-lin; Duan Cy, Chun-ying; Tian Yp, Yu-peng; You Xz, Xiao-zeng; Huang Xy, Xiao-ying

    1996-04-10

    The titled compound, (tris(2-aminoethyl)amine)(4,5-diazafluoren-9-one) copper(II) perchlorate, [Cu(C(6)H(18)N(4))(C(11)H(6)N(2)O)(ClO(4))(2)], 1, has been designed, synthesized, and characterized. The electronic and ESR spectra are very different from those of [Cu(tren)L](2+) complexes where L is monodentate ligand. The X-ray analysis revealed that the complex crystallizes in the monoclinic space group P2(1)/c, with a = 10.726(6) Å, b = 14.921(7) Å, c = 14.649(4) Å, beta = 95.13(3) degrees, and Z = 4. The copper(II) ion is coordinated by four nitrogen atoms from tris(2-aminoethyl)amine (tren) and two nitrogen atoms from 4,5-diazafluoren-9-one (dzf) to form an unusual six-coordinate (4 + 1 + 1') geometry. The structure is very rare, and to our knowledge, it is the first example of an asymmetric bidentate phenanthroline derivative metal complex. The structure could be used as a model of the associative complex in the ligand-exchange and ligand-substitution reactions of [Cu(tren)L](2+) and the catalytic mechanisms of enzymes involving copper sites. From the electronic and variable-temperature ESR spectra in solution, the possible mechanism of these reactions has also been proposed. As a comparison, the complex [Cu(tren)(ImH)(ClO(4))(2)], 2, was also synthesized and characterized, where ImH is imidazole.

  7. Halo-substituted thiosemicarbazones and their copper(II), nickel(II) complexes: detailed spectroscopic characterization and study of antitumour activity against HepG2 human hepatoblastoma cells.

    Science.gov (United States)

    Jagadeesh, M; Kalangi, Suresh K; Sivarama Krishna, L; Reddy, A Varada

    2014-01-24

    Copper(II) and nickel(II) complexes of two different halogen substituted thiosemicarbazone ligands were synthesized. The ligands 3,4-difluoroacetophenone thiosemicarbazone (1) and 2-bromo-4'-chloroacetophenone thiosemicarbazone (2) were characterized and confirmed spectroscopically by FT-IR, FT-Raman, UV-vis and fluorescence spectral analysis, while the respective copper(II) complexes [Cu(C9H9N3F2S)2Cl2] (1a), [Cu(C9H9N3ClBrS)2Cl2] (2a) and nickel(II) complexes [Ni(C9H9N3F2S)2] (1b), [Ni(C9H9N3ClBrS)2] (2b) were characterized by FT-IR, UV-vis and electron paramagnetic spectroscopy (EPR). The EPR spectra of the Cu(II) complexes provided the rhombic octahedral and axial symmetry of the complexes 1a and 2a respectively. For the complex 1a, the g values calculated as g1=2.1228, g2=2.0706 and g3=2.001 between 2900 and 3300 G. While for the complex 2a, a set of two resonance absorptions were observed. The synthesized compounds were tested for antitumor activity and showed that the ability to kill liver cancer cells significantly. Out of all the synthesized compounds, copper(II) complexes 1a and 2a showed high cytotoxic effect on liver cancer cells with 67.51% and 42.77% of cytotoxicity respectively at 100 μM.

  8. Halo-substituted thiosemicarbazones and their copper(II), nickel(II) complexes: Detailed spectroscopic characterization and study of antitumour activity against HepG2 human hepatoblastoma cells

    Science.gov (United States)

    Jagadeesh, M.; Kalangi, Suresh K.; Sivarama Krishna, L.; Reddy, A. Varada

    2014-01-01

    Copper(II) and nickel(II) complexes of two different halogen substituted thiosemicarbazone ligands were synthesized. The ligands 3,4-difluoroacetophenone thiosemicarbazone (1) and 2-bromo-4'-chloroacetophenone thiosemicarbazone (2) were characterized and confirmed spectroscopically by FT-IR, FT-Raman, UV-vis and fluorescence spectral analysis, while the respective copper(II) complexes [Cu(C9H9N3F2S)2Cl2] (1a), [Cu(C9H9N3ClBrS)2Cl2] (2a) and nickel(II) complexes [Ni(C9H9N3F2S)2] (1b), [Ni(C9H9N3ClBrS)2] (2b) were characterized by FT-IR, UV-vis and electron paramagnetic spectroscopy (EPR). The EPR spectra of the Cu(II) complexes provided the rhombic octahedral and axial symmetry of the complexes 1a and 2a respectively. For the complex 1a, the g values calculated as g1 = 2.1228, g2 = 2.0706 and g3 = 2.001 between 2900 and 3300 G. While for the complex 2a, a set of two resonance absorptions were observed. The synthesized compounds were tested for antitumor activity and showed that the ability to kill liver cancer cells significantly. Out of all the synthesized compounds, copper(II) complexes 1a and 2a showed high cytotoxic effect on liver cancer cells with 67.51% and 42.77% of cytotoxicity respectively at 100 μM.

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

    Directory of Open Access Journals (Sweden)

    Zhong Zheng

    2015-01-01

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

  10. Copper resistance in Pseudomonas syringae mediated by periplasmic and outer membrane proteins.

    OpenAIRE

    Cha, J S; Cooksey, D A

    1991-01-01

    Copper-resistant strains of Pseudomonas syringae pathovar tomato accumulate copper and develop blue colonies on copper-containing media. Three of the protein products of the copper-resistance operon (cop) were characterized to provide an understanding of the copper-resistance mechanism and its relationship to copper accumulation. The Cop proteins, CopA (72 kDa), CopB (39 kDa), and CopC (12 kDa), were produced only under copper induction. CopA and CopC were periplasmic proteins and CopB was an...

  11. Proline improves copper tolerance in chickpea (Cicer arietinum).

    Science.gov (United States)

    Singh, Vijeta; Bhatt, Indu; Aggarwal, Anjali; Tripathi, Bhumi Nath; Munjal, Ashok Kumar; Sharma, Vinay

    2010-09-01

    The present study suggests the involvement of proline in copper tolerance of four genotypes of Cicer arietinum (chickpea). Based on the data of tolerance index and lipid peroxidation, the order for copper tolerance was as follows: RSG 888 > CSG 144 > CSG 104 > RSG 44 in the selected genotypes. The basis of differential copper tolerance in chickpea genotypes was characterized by analyzing, antioxidant enzymes (superoxide dismutase, ascorbated peroxidase and catalase), phytochelatins, copper uptake, and proline accumulation. Chickpea genotypes showed stimulated superoxide dismutase activity at all tested concentrations of copper, but H(2)O(2) decomposing enzymes especially; ascorbate peroxidase did not increase with 25 and 50 microM copper treatments. Catalase activity, however, increased at lower copper concentrations but failed to stimulate at 50 microM copper. Such divergence in responses of these enzymes minimizes their importance in protecting chickpea against copper stress. The sensitive genotypes showed greater enhancement of phytochelatins than that of tolerant genotypes. Hence, the possibility of phytochelatins in improving copper tolerance in the test plant is also excluded. Interestingly, the order of proline accumulation in the chickpea genotypes (RSG 888 > CSG 144 > CSG 104 > RSG 44) was exactly similar to the order of copper tolerance. Based on hyperaccumulation of proline in tolerant genotype (RSG 44) and the reduction and improvement of lipid peroxidation and tolerance index, respectively, by proline pretreatment, we conclude that hyperaccumulation of proline improves the copper tolerance in chickpea.

  12. Synthesis and characterization of strontium molybdate doped with copper, cobalt and zinc for purposes photocatalytic; Sintese e caracterizacao do molibdato de estroncio dopado com cobre, cobalto e zinco para fins fotocataliticos

    Energy Technology Data Exchange (ETDEWEB)

    Dutra, F.B.; Silva, M.M.S.; Moriyama, A.L.L.; Souza, C.P., E-mail: faby_qui@hotmail.com [Universidade Federal do Rio Grande do Norte (LAMNRC/UFRN), Natal, RN (Brazil). Lab. de Materiais Nanoestruturados e Reatores Catalicos

    2016-07-01

    The broad concerns of contemporary society with environmental problems requires legislation and more effective techniques for wastewater treatment. In recent years, ceramic materials that have properties such as high melting points and high stability have been receiving great emphasis in several studies in particular heterogeneous photocatalysis, rapid and efficient method for the complete mineralization of contaminants. In this context, the present work deals with the synthesis and characterization of molybdate Strontium (SrMoO4) doped with copper, cobalt and zinc for the purpose of photocatalytic studies. The compounds were synthesized by complexation method EDTA / Citrate basic medium. The powders were characterized by Thermogravimetric Analysis (TG), X-Ray Diffraction (XRD), Particle size distribution by laser diffraction, Spectroscopy in the UV-Visible region, Energy Dispersive Spectroscopy (EDS) and Scanning Electron Microscopy (SEM), showing promising results as the crystalline phase of development and potential uses for the purpose of heterogeneous photocatalysis. (author)

  13. Effect of weld parameter on mechanical and metallurgical properties of dissimilar joints AA6082–AA6061 in T6 condition produced by FSW

    Directory of Open Access Journals (Sweden)

    H. S. Patil

    2013-04-01

    Full Text Available The effect of processing parameters on the mechanical and metallurgical properties of dissimilar joints of AA6082–AA6061 produced by friction stir welding was analysed in this study. Different FSW samples were produced by varying the welding speeds of the tool as 50 and 62 mm/min and by varying the alloy positioned on the advancing side of the tool. In all the experiments the rotating speed is fixed at 1600rpm. All the welds were produced perpendicularly to the rolling direction for both the alloys. Microhardness (HV and tensile tests performed at room temperature were used to evaluate the mechanical properties of the joints. In order to analyse the microstructural evolution of the material, the weld’s cross-sections were observed optically and SEM observations were made of the fracture surfaces. The corrosion tests of base alloy and welded joints were carried out in 3.5%NaCl solution at a room temperature. Corrosion current and potential were determined using potentiostatic polarization measurements. It was found that the corrosion rates of welded joints were higher than that of base alloy.

  14. Synthesis and Characterization of Copper-Based Aerogel%氧化铜气凝胶的制备与结构表征

    Institute of Scientific and Technical Information of China (English)

    毕于铁; 任洪波; 张庆军; 杨静; 张林

    2012-01-01

    Copper-based aerogel was prepared by sol-gel method using inorganic salt as precursor. The morphology of copper-based aerogels was evaluated by field-emission scanning electron microscope (FESEM) and high-resolution transmission electron microscopy (HRTEM). The results suggest that the aerogels are made up of three-dimensional porous structure. The X-ray diffraction (XRD) patterns show that the as-prepared copper-based aerogel belongs to amorphous material. The calcination of the as-prepared aerogels at different temperatures induces a phase change which results in the formation of a copper oxide aerogel. The N2 adsorption/desorption shows that the copper-based aerogel has a high surface area.%以CuSO4·5H2O为前驱体,聚丙烯酸为分散剂,采用溶胶-凝胶法制备出铜基复合气凝胶,该气凝胶经高温热处理后得到氧化铜气凝胶.通过场发射扫描电镜(FESEM)、高分辨透射电镜(HRTEM)、X射线衍射(XRD)以及N2吸附对气凝胶的结构进行了表征.结果表明:铜基复合气凝胶是由大量球状颗粒堆积而成的;经不同温度热处理,气凝胶逐渐由三维网络状结构转变为致密结构.XRD谱表明,该材料为无定形态,随处理温度的升高,气凝胶的晶型不断变化,并最终变为氧化铜气凝胶.N2吸附结果表明,经不同温度处理后,气凝胶样品具有较高的比表面积.

  15. Mechanical Properties, Microstructure and Crystallographic Texture of Magnesium AZ91-D Alloy Welded by Friction Stir Welding (FSW)

    Science.gov (United States)

    Kouadri-Henni, A.; Barrallier, L.

    2014-10-01

    The objective of the study was to characterize the properties of a magnesium alloy welded by friction stir welding. The results led to a better understanding of the relationship between this process and the microstructure and anisotropic properties of alloy materials. Welding principally leads to a large reduction in grain size in welded zones due to the phenomenon of dynamic recrystallization. The most remarkable observation was that crystallographic textures appeared from a base metal without texture in two zones: the thermo-mechanically affected and stir-welded zones. The latter zone has the peculiarity of possessing a marked texture with two components on the basal plane and the pyramidal plane. These characteristics disappeared in the thermo-mechanically affected zone (TMAZ), which had only one component following the basal plane. These modifications have been explained by the nature of the plastic deformation in these zones, which occurs at a moderate temperature in the TMAZ and high temperature in the SWZ.

  16. Long-term integrity of copper overpack

    Energy Technology Data Exchange (ETDEWEB)

    Holmstroem, Stefan; Salonen, Jorma; Auerkari, Pertti (VTT, Esbo (FI)); Saukkonen, Tapio (Helsinki Univ. of Technology, Esbo (FI))

    2007-05-15

    The results from extended uniaxial and multiaxial creep testing confirm the earlier indications of microstructural changes at relatively low temperatures (150-175 deg C) in Cu-OFP. These changes are probably related to recovery processes directed by the favourable crystallographic orientation on one side the related grain boundary, resulting in characteristically widening grain boundary zones. With further straining, these zones become chains of small grains decorating the original grain boundaries. The observed microstructural changes do not appear to represent particular disadvantages in terms of remaining life. In creep testing with natural weld defects (FSW, inclusion sheet 20% of cross-section), the results show much faster decreasing creep strength in time than what is observed for base material or welds without defects. However, extrapolation to 50 MPa stress level across such a defective region would still suggest a safe life of approximately 26,000 years in spite of much elevated testing temperature (175 deg C) from expected service temperature (below 100 deg C). For predicting mechanical behaviour, a creep model has been developed to include the full creep curves in a simple and robust manner. The model has been adapted to the most recent creep testing results (up to about 48,000 h in uniaxial testing). Applying this model for the extrapolated case of steady loading at 100 deg C / 50 MPa predicts time to 10% strain of about one million years. For comparison on creep ductility, also a testing program on low-phosphorus (OFHC) copper was initiated. The testing program with model vessels was completed after confirming safe short term limit load predictions. This program continues with compact tension specimens to study the potential combined effect of creep and corrosion in simulated groundwater

  17. Unraveling the Active Site in Copper-ceria Systems for the Water Gas Shift Reaction: In-situ Characterization of an Inverse Powder CeO2-x/CuO-Cu Catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.A.; Barrio, L.; Estrella, M.; Zhou, G.; Wen, W.; Hanson, J.C.; Hungría, A.B.; Hornés, A.; Fernández-García, M.; Arturo Martínez-Arias, A.

    2010-03-04

    An inverse powder system composed of CeO{sub 2} nanoparticles dispersed over a CuO-Cu matrix is proposed as a novel catalyst for the water-gas shift reaction. This inverse CeO{sub 2}/CuO-Cu catalyst exhibits a higher activity than standard Cu/CeO{sub 2} catalysts. In situ synchrotron characterization techniques were employed to follow the structural changes of CeO{sub 2}/CuO-Cu under reaction conditions. Time-resolved X-ray diffraction experiments showed the transformation of CuO to metallic Cu via a Cu{sub 2}O intermediate. Short-order structural changes were followed by pair distribution function analysis and corroborated the results obtained by diffraction. Moreover, X-ray absorption spectroscopy also revealed oxidation state changes from Cu{sup 2+} to Cu{sup 0} and the partial reduction of CeOx nanoparticles. The activity data obtained by mass spectrometry revealed that hydrogen production starts once the copper has been fully reduced. The strong interaction of ceria and copper boosted the catalytic performance of the sample. The inverse catalyst was active at low temperatures, stable to several reaction runs and to redox cycles. These characteristics are highly valuable for mobile fuel cell applications. The active phases of the inverse CeO{sub 2}/CuO-Cu catalyst are partially reduced ceria nanoparticles strongly interacting with metallic copper. The nature and structure of the ceria nanoparticles are of critical importance because they are involved in processes related to water dissociation over the catalyst surface.

  18. Unraveling the Active Site in Copper-Ceria Systems for the Water-Gas Shift Reaction: In Situ Characterization of an Inverse Powder CeO2-x/CuO-Cu Catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Barrio, L.; Estrella, M; Zhou, G; Wen, W; Hanson, J; Hungria, A; Hornes, A; Fernandez-Garcia, M; Martinez-Arias, A; Rodriguez, J

    2010-01-01

    An inverse powder system composed of CeO{sub 2} nanoparticles dispersed over a CuO-Cu matrix is proposed as a novel catalyst for the water-gas shift reaction. This inverse CeO{sub 2}/CuO-Cu catalyst exhibits a higher activity than standard Cu/CeO{sub 2} catalysts. In situ synchrotron characterization techniques were employed to follow the structural changes of CeO{sub 2}/CuO-Cu under reaction conditions. Time-resolved X-ray diffraction experiments showed the transformation of CuO to metallic Cu via a Cu{sub 2}O intermediate. Short-order structural changes were followed by pair distribution function analysis and corroborated the results obtained by diffraction. Moreover, X-ray absorption spectroscopy also revealed oxidation state changes from Cu{sup 2+} to Cu{sup 0} and the partial reduction of CeO{sub x} nanoparticles. The activity data obtained by mass spectrometry revealed that hydrogen production starts once the copper has been fully reduced. The strong interaction of ceria and copper boosted the catalytic performance of the sample. The inverse catalyst was active at low temperatures, stable to several reaction runs and to redox cycles. These characteristics are highly valuable for mobile fuel cell applications. The active phases of the inverse CeO{sub 2}/CuO-Cu catalyst are partially reduced ceria nanoparticles strongly interacting with metallic copper. The nature and structure of the ceria nanoparticles are of critical importance because they are involved in processes related to water dissociation over the catalyst surface.

  19. Role of copper oxides in contact killing of bacteria.

    Science.gov (United States)

    Hans, Michael; Erbe, Andreas; Mathews, Salima; Chen, Ying; Solioz, Marc; Mücklich, Frank

    2013-12-31

    The potential of metallic copper as an intrinsically antibacterial material is gaining increasing attention in the face of growing antibiotics resistance of bacteria. However, the mechanism of the so-called "contact killing" of bacteria by copper surfaces is poorly understood and requires further investigation. In particular, the influences of bacteria-metal interaction, media composition, and copper surface chemistry on contact killing are not fully understood. In this study, copper oxide formation on copper during standard antimicrobial testing was measured in situ by spectroscopic ellipsometry. In parallel, contact killing under these conditions was assessed with bacteria in phosphate buffered saline (PBS) or Tris-Cl. For comparison, defined Cu2O and CuO layers were thermally generated and characterized by grazing incidence X-ray diffraction. The antibacterial properties of these copper oxides were tested under the conditions used above. Finally, copper ion release was recorded for both buffer systems by inductively coupled plasma atomic absorption spectroscopy, and exposed copper samples were analyzed for topographical surface alterations. It was found that there was a fairly even growth of CuO under wet plating conditions, reaching 4-10 nm in 300 min, but no measurable Cu2O was formed during this time. CuO was found to significantly inhibit contact killing, compared to pure copper. In contrast, thermally generated Cu2O was essentially as effective in contact killing as pure copper. Copper ion release from the different surfaces roughly correlated with their antibacterial efficacy and was highest for pure copper, followed by Cu2O and CuO. Tris-Cl induced a 10-50-fold faster copper ion release compared to PBS. Since the Cu2O that primarily forms on copper under ambient conditions is as active in contact killing as pure copper, antimicrobial objects will retain their antimicrobial properties even after oxide formation.

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

    Science.gov (United States)

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

    1982-01-30

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

  1. Spectroscopic studies of copper enzymes

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-05-01

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

  2. Copper complexes as chemical nucleases

    Indian Academy of Sciences (India)

    Akhil R Chakravarty; Pattubala A N Reddy; Bidyut K Santra; Anitha M Thomas

    2002-08-01

    Redox active mononuclear and binuclear copper(II) complexes have been prepared and structurally characterized. The complexes have planar N-donor heterocyclic bases like 1,10-phenanthroline (phen), dipyridoquinoxaline (dpq) and dipyridophenazine (dppz) ligands that are suitable for intercalation to B-DNA. Complexes studied for nuclease activity have the formulations [Cu(dpq)2(H2O)] (ClO4)2.H2O (1), [{CuL(H2O)}2(-ox)](ClO4)2 (L = bpy, 2; phen, 3; dpq, 4; and dppz, 5) and [Cu(L)(salgly)] (L = bpy, 6; phen, 7; dpq, 8; and dppz, 9), where salgly is a tridentate Schiff base obtained from the condensation of glycine and salicylaldehyde. The dpq complexes are efficient DNA binding and cleavage active species. The dppz complexes show good binding ability but poor nuclease activity. The cleavage activity of the bis-dpq complex is significantly higher than the bis-phen complex of copper(II). The nuclease activity is found to be dependent on the intercalating nature of the complex and on the redox potential of the copper(II)/copper(I) couple. The ancillary ligand plays a significant role in binding and cleavage activity.

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

    Science.gov (United States)

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

    2008-12-01

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

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

    Science.gov (United States)

    Thiery, M

    1983-10-01

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

  5. Borohidreto complexos de cobre (I contendo difosfinas: caracterização espectroscópica e comportamento térmico Tetrahydroborate complexes of copper (I with diphosphines: spectroscopic characterization and thermal behavior

    Directory of Open Access Journals (Sweden)

    Paula S. Haddad

    2001-12-01

    Full Text Available Tetrahydroborate complexes of copper (I with bidentate phosphines, [Cu(eta²-BH4(dppm] (1, [Cu(eta²-BH4(dppe] (2, [Cu(eta²-BH4(cis-dppet] (3 and [Cu(eta²-BH4(dppb] (4 (dppm = bis(diphenylphosphinomethane; dppe = 1,2-bis(diphenylphosphino ethane; cis-dppet = 1,2-cis(diphenylphosphinoethene; dppb = 1,4-bis(diphenylphosphinobutane were prepared and characterized by elemental analysis, infrared spectroscopy, NMR and thermogravimetric analysis. The IR data for 1-4 showed bands typical of a bidentate coordination of BH4 group to the copper atom and the 31P{¹H} NMR spectra indicated that the phosphorous atoms are chelating the metal centre. The thermal behavior of the compounds was investigated and suggested that their thermal stability is influenced by the phosphines. Their thermal stability decreased as follows: [Cu(eta²-BH4(dppe] (2 > [Cu(eta²-BH4(dppm] (1 > [Cu(eta²-BH4(dppb] (4 > [Cu(eta²-BH4(cis-dppet] (3. According to thermal analysis and X-ray diffraction patterns all compounds decomposed giving Cu(BO22, CuO, CuO2 and Cu as final products.

  6. Synthesis, characterization, crystal structure determination and computational study of a new Cu(II) complex of bis [2-{(E)-[2-chloroethyl)imino]methyl}phenolato)] copper(II) Schiff base complex

    Science.gov (United States)

    Grivani, Gholamhossein; Vakili, Mohammad; Khalaji, Aliakbar Dehno; Bruno, Giuseppe; Rudbari, Hadi Amiri; Taghavi, Maedeh

    2016-07-01

    The copper (II) Schiff base complex of [CuL2] (1), HL = 2-{(E)-[2-chloroethyl) imino]methyl}phenol, has been synthesized and characterized by elemental (CHN) analysis, UV-Vis and FT-IR spectroscopy. The molecular structure of 1 was determined by single crystal X-ray diffraction technique. The conformational analysis and molecular structures of CuL2 were investigated by means of density functional theory (DFT) calculations at B3LYP/6-311G* level. An excellent agreement was observed between theoretical and experimental results. The Schiff base ligand of HL acts as a chelating ligand and coordinates via one nitrogen atom and one oxygen atom to the metal center. The copper (II) center is coordinated by two nitrogen atoms and two oxygen atoms from two Schiff base ligands in an approximately square planar trans-[MN2O2] coordination geometry. Thermogravimetric analysis of CuL2 showed that it was decomposed in five stages. In addition, the CuL2 complex thermally decomposed in air at 660 °C and the XRD pattern of the obtained solid showed the formation of CuO nanoparticles with an average size of 34 nm.

  7. 2,6-Bis(2,6-diethylphenyliminomethyl)pyridine coordination compounds with cobalt(II), nickel(II), copper(II), and zinc(II): synthesis, spectroscopic characterization, X-ray study and in vitro cytotoxicity.

    Science.gov (United States)

    Martinez-Bulit, Pablo; Garza-Ortíz, Ariadna; Mijangos, Edgar; Barrón-Sosa, Lidia; Sánchez-Bartéz, Francisco; Gracia-Mora, Isabel; Flores-Parra, Angelina; Contreras, Rosalinda; Reedijk, Jan; Barba-Behrens, Norah

    2015-01-01

    Coordination compounds with cobalt(II), nickel(II), copper(II) and zinc(II) and the ligand 2,6-bis(2,6-diethylphenyliminomethyl)pyridine (L) were synthesized and fully characterized by IR and UV-Vis-NIR spectroscopy, elemental analysis, magnetic susceptibility and X-ray diffraction for two representative cases. These novel compounds were designed to study their activity as anti-proliferative drugs against different human cancer cell lines. The tridentate ligand forms heptacoordinated compounds from nitrate metallic salts, where the nitrate acts in a chelating form to complete the seven coordination positions. In vitro cell growth inhibition was measured for Co(II), Cu(II) and Zn(II) complexes, as well as for the free ligand. Upon coordination, the IC50 value of the transition-metal compounds is improved compared to the free ligand. The copper(II) and zinc(II) compounds are the most promising candidates for further in vitro and in vivo studies. The activity against colon and prostate cell lines merits further research, in views of the limited therapeutic options for such cancer types.

  8. Synthesis and characterization of cobalt(II), nickel(II), copper(II) and zinc(II) complexes with Schiff base derived from 4-amino-3-mercapto-6-methyl-5-oxo-1,2,4-triazine.

    Science.gov (United States)

    Singh, Kiran; Barwa, Manjeet Singh; Tyagi, Parikshit

    2007-03-01

    A few (1:1) and (1:2) metal complexes of cobalt(II), nickel(II), copper(II) and zinc(II) have been isolated with ligand derived from the condensation of 4-amino-3-mercapto-6-methyl-5-oxo-1,2,4-triazine with 2-acetylpyridine (L(1)) and characterized by elemental analysis, conductivity measurements, infrared, electronic, (1)H NMR spectral data, magnetic and thermogravimetric analyses. Due to insolubility in water and most of the common organic solvents and infusibility at higher temperatures, all the complexes are thought to be polymeric in nature. A square-planar geometry was suggested for copper(II) and octahedral proposed for cobalt(II), nickel(II) and zinc(II). Some of the chemically synthesized compounds have been screened in vitro against the three Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis and Bacillus subtilis) and two Gram-negative (Salmonella typhi and Escherichia coli) organisms. It is observed that the coordination of metal ion has pronounced effect on the microbial activities of the ligand. The metal complexes have higher antimicrobial effect than the free ligands.

  9. Combustion synthesis by reaction and characterization of structural Ni-Zn ferrite doped with copper; Sintese por reacao de combustao e caracterizacao estrutural de ferritas Ni-Zn dopadas com cobre

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, J.; Santos, J.R.D.; Cunha, R.B.L.; Feitosa, C.A.; Costa, A.C.F.M., E-mail: joeldadantas@yahoo.com.br, E-mail: jakelineedm@gmail.com [Universidade Federal de Campina Grande (LabSMac/UFCG), PB (Brazil). Lab. de Sintese de Materiais Ceramicos

    2012-07-01

    The present stud aims to evaluate the effect of doping with Cu{sup 2+} ions concentrations of 0.0, 0.1, 0.2, 0.3 and 0.4 mol in the synthesis and structure of Ni-Zn ferrite. Samples were synthesized by the method of the combustion reaction and characterized by measuring the temperature as a function of reaction time, X-ray diffraction (XRD) and infrared spectroscopy in Fourier transform (FTIR). The combustion temperature and time were 646, 900, 989, 975 and 735°C and 210, 175, 220, 210 and 110 seconds for the sample doped with 0.0, 0.1, 0.2, 0.3 and 0.4 mol of copper, respectively. XRD results show that all concentrations of copper evaluated, there was only a training phase inverse spinel ferrite and Ni-Zn FTIR spectra show absorption bands below 1000cm{sup -1}, which are characteristics of the spinel type AB{sub 2}O{sub 4-} (author)

  10. Desarrollo de Complejos de Cobre con Actividad Antitumoral: Síntesis y Caracterización de un nuevo Complejo de Cobre-Terpiridina Development of Copper Complexes with Antitumor Activity: Synthesis and Characterization of a new Copper-Terpyridine Complex

    Directory of Open Access Journals (Sweden)

    Gianella Facchin

    2012-01-01

    Full Text Available El objetivo de este trabajo es la síntesis y caracterización de nuevos complejos de Cobre(II y 2,2':6'2''-terpiridina y la evaluación de su actividad antitumoral, como parte de una investigación de complejos de Cu(II con actividad citotóxica. La estructura del nuevo complejo [Cu(terpy(H2O(SO4]∙2H2O se caracterizó por espectroscopía infrarroja en estado sólido y en solución acuosa, espectroscopía electrónica, conductimetría y voltametría cíclica. Se realizaron ensayos de lipofilia y de actividad antiproliferativa en células HeLa. Se determinó que el compuesto obtenido presenta un átomo de Cobre(II coordinado con una molécula de terpiridina y un anión sulfato. En solución acuosa, el anión sulfato es sustituido por moléculas de agua formándose el ion [Cu(terpy(H2O3]2+. Los estudios de lipofilia muestran un coeficiente de reparto n-octanol/agua de 1,3, que es similar a los valores encontrados para otros compuestos con actividad biológica. El compuesto presenta actividad antiproliferativa de 25 % de inhibición a 25 µM.The aim of this research is the synthesis and characterization of new Copper(II-2,2':6'2''-terpyridine complexes, as well as the evaluation of their antitumor activity, as a part of a project on copper complexes with cytotoxic activity. The new complex [Cu(terpy(H2O(SO4]∙2H2O was characterized by infrared spectroscopy in solid state and aqueous solution, electronic spectra, conductimetry and cyclic voltammetry. Besides, its lipophilicity and antriproliferative activity in HeLa cells cultures were assessed. The results show that there is a copper atom in the complex that is coordinated to a terpyridine molecule and a sulphate anion. Aqueous solution behavior indicates that the sulphate anion is replaced by three water molecules being [Cu(terpy(H2O3]2+ the resulting ion. Lipophilicity studies show a partition coefficient between n-octanol and water of 1,3, similar to other compounds presenting biological

  11. Inherited copper transport disorders: biochemical mechanisms, diagnosis, and treatment.

    Science.gov (United States)

    Kodama, Hiroko; Fujisawa, Chie; Bhadhprasit, Wattanaporn

    2012-03-01

    Copper is an essential trace element required by all living organisms. Excess amounts of copper, however, results in cellular damage. Disruptions to normal copper homeostasis are hallmarks of three genetic disorders: Menkes disease, occipital horn syndrome, and Wilson's disease. Menkes disease and occipital horn syndrome are characterized by copper deficiency. Typical features of Menkes disease result from low copper-dependent enzyme activity. Standard treatment involves parenteral administration of copper-histidine. If treatment is initiated before 2 months of age, neurodegeneration can be prevented, while delayed treatment is utterly ineffective. Thus, neonatal mass screening should be implemented. Meanwhile, connective tissue disorders cannot be improved by copper-histidine treatment. Combination therapy with copper-histidine injections and oral administration of disulfiram is being investigated. Occipital horn syndrome characterized by connective tissue abnormalities is the mildest form of Menkes disease. Treatment has not been conducted for this syndrome. Wilson's disease is characterized by copper toxicity that typically affects the hepatic and nervous systems severely. Various other symptoms are observed as well, yet its early diagnosis is sometimes difficult. Chelating agents and zinc are effective treatments, but are inefficient in most patients with fulminant hepatic failure. In addition, some patients with neurological Wilson's disease worsen or show poor response to chelating agents. Since early treatment is critical, a screening system for Wilson's disease should be implemented in infants. Patients with Wilson's disease may be at risk of developing hepatocellular carcinoma. Understanding the link between Wilson's disease and hepatocellular carcinoma will be beneficial for disease treatment and prevention.

  12. Characterization of Exposures to Airborne Nanoscale Particles During Friction Stir Welding of Aluminum

    Science.gov (United States)

    Pfefferkorn, Frank E.; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; Mccarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M. Abbas; Gruetzmacher, George; Hoover, Mark D.

    2010-01-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 μm) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 μm) with 1-s resolution, lung deposited surface areas, and PM2.5 concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 μm) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at ∼30 and ∼550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at ∼4.0 × 105 particles cm−3, whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm−3, depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10–100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) μg m−3; the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may exist, especially in larger scale industrial

  13. Characterization of exposures to airborne nanoscale particles during friction stir welding of aluminum.

    Science.gov (United States)

    Pfefferkorn, Frank E; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; McCarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M Abbas; Gruetzmacher, George; Hoover, Mark D

    2010-07-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 microm) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 microm) with 1-s resolution, lung deposited surface areas, and PM(2.5) concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 microm) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at approximately 30 and approximately 550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at approximately 4.0 x 10(5) particles cm(-3), whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm(-3), depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10-100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) microg m(-3); the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may

  14. A study aimed at characterizing the interfacial structure in a tin–silver solder on nickel-coated copper plate during aging

    Indian Academy of Sciences (India)

    D C Lin; R Kovacevic; T S Srivatsan; G X Wang

    2008-06-01

    This paper highlights the interfacial structure of tin-silver (Sn-3·5Ag) solder on nickel-coated copper pads during aging performance studies at a temperature of 150°C for up to 96 h. Experimental results revealed the as-solidified solder bump made from using the lead-free solder (Sn-3·5Ag) exhibited or showed a thin layer of the tin–nickel–copper intermetallic compound (IMC) at the solder/substrate interface. This includes a sub-layer having a planar structure immediately adjacent to the Ni-coating and a blocky structure on the inside of the solder. Aging performance studies revealed the thickness of both the IMC layer and the sub-layer, having a planar structure, to increase with an increase in aging time. The observed increase was essentially non-linear. Fine microscopic cracks were observed to occur at the interfaces of the planar sub-layer and the block sub-layer.

  15. Structural and functional characterization of the Geobacillus copper nitrite reductase: involvement of the unique N-terminal region in the interprotein electron transfer with its redox partner.

    Science.gov (United States)

    Fukuda, Yohta; Koteishi, Hiroyasu; Yoneda, Ryohei; Tamada, Taro; Takami, Hideto; Inoue, Tsuyoshi; Nojiri, Masaki

    2014-03-01

    The crystal structures of copper-containing nitrite reductase (CuNiR) from the thermophilic Gram-positive bacterium Geobacillus kaustophilus HTA426 and the amino (N)-terminal 68 residue-deleted mutant were determined at resolutions of 1.3Å and 1.8Å, respectively. Both structures show a striking resemblance with the overall structure of the well-known CuNiRs composed of two Greek key β-barrel domains; however, a remarkable structural difference was found in the N-terminal region. The unique region has one β-strand and one α-helix extended to the northern surface of the type-1 copper site. The superposition of the Geobacillus CuNiR model on the electron-transfer complex structure of CuNiR with the redox partner cytochrome c551 in other denitrifier system led us to infer that this region contributes to the transient binding with the partner protein during the interprotein electron transfer reaction in the Geobacillus system. Furthermore, electron-transfer kinetics experiments using N-terminal residue-deleted mutant and the redox partner, Geobacillus cytochrome c551, were carried out. These structural and kinetics studies demonstrate that the region is directly involved in the specific partner recognition.

  16. Synthesis and structural characterization of five new copper (I) complexes with 1,10-phenanthroline and 1,4-bis(diphenylphosphino)butane(dppb)

    Science.gov (United States)

    Li, Jian-Bao; Fan, Wei-Wei; Min-Liu; Xiao, Ye-Lan; Jin, Qiong-Hua; Li, Zhong-Feng

    2015-04-01

    The mixture of copper(I) salts CuX (X = Cl, Br, SCN, CN, SO3CF3) and 1,10-phenanthroline (phen) reacts with 1,4-bis(diphenylphosphino)butane (dppb) to give dinuclear complexes [Cu2(dppb)(phen)2Cl2]ṡ4DMF (1), [Cu2(dppb)(phen)2Br2]ṡDMF (2), [Cu2(dppb)(phen)2(SCN)2] (3) and two 1D chain complexes {[Cu2(dppb)(phen)2(CN)2(H2O)]}nṡnH2O (4) and {[Cu2(dppb)(phen)2](SO3CF3)2}n (5), respectively. The structures of these compounds were investigated by elemental analysis, single-crystal X-ray diffraction, electronic absorption spectroscopy, fluorescence spectroscopy, 1H NMR and 31P NMR spectroscopy. Each Cu atom adopts a distorted tetrahedral configuration, and all the complexes are considerably air-stable in solid state and in solution. Detailed NMR studies have been performed to disclose the behavior of the prepared copper(I) complexes in solution. All the five complexes are bright green and cyan luminophores in a solid state at room temperature. This makes them potential candidates as cheap emitting materials for electroluminescent devices.

  17. Copper does not alter the intracellular distribution of ATP7B, a copper-transporting ATPase.

    Science.gov (United States)

    Harada, M; Sakisaka, S; Kawaguchi, T; Kimura, R; Taniguchi, E; Koga, H; Hanada, S; Baba, S; Furuta, K; Kumashiro, R; Sugiyama, T; Sata, M

    2000-09-01

    Wilson's disease is a genetic disorder characterized by the accumulation of copper in the body due to a defect of biliary copper excretion. However, the mechanism of biliary copper excretion has not been fully clarified. We examined the effect of copper on the intracellular localization of the Wilson disease gene product (ATP7B) and green fluorescent protein (GFP)-tagged ATP7B in a human hepatoma cell line (Huh7). The intracellular organelles were visualized by fluorescence microscopy. GFP-ATP7B colocalized with late endosome markers, but not with endoplasmic reticulum, Golgi, or lysosome markers in both the steady and copper-loaded states. ATP7B mainly localized at the perinuclear regions in both states. These results suggest that the main localization of ATP7B is in the late endosomes in both the steady and copper-loaded states. ATP7B seems to translocate copper from the cytosol to the late endosomal lumen, thus participating in biliary copper excretion via lysosomes.

  18. Urinary copper elevation in a mouse model of Wilson's disease is a regulated process to specifically decrease the hepatic copper load.

    Directory of Open Access Journals (Sweden)

    Lawrence W Gray

    Full Text Available Body copper homeostasis is regulated by the liver, which removes excess copper via bile. In Wilson's disease (WD, this function is disrupted due to inactivation of the copper transporter ATP7B resulting in hepatic copper overload. High urinary copper is a diagnostic feature of WD linked to liver malfunction; the mechanism behind urinary copper elevation is not fully understood. Using Positron Emission Tomography-Computed Tomography (PET-CT imaging of live Atp7b(-/- mice at different stages of disease, a longitudinal metal analysis, and characterization of copper-binding molecules, we show that urinary copper elevation is a specific regulatory process mediated by distinct molecules. PET-CT and atomic absorption spectroscopy directly demonstrate an age-dependent decrease in the capacity of Atp7b(-/- livers to accumulate copper, concomitant with an increase in urinary copper. This reciprocal relationship is specific for copper, indicating that cell necrosis is not the primary cause for the initial phase of metal elevation in the urine. Instead, the urinary copper increase is associated with the down-regulation of the copper-transporter Ctr1 in the liver and appearance of a 2 kDa Small Copper Carrier, SCC, in the urine. SCC is also elevated in the urine of the liver-specific Ctr1(-/- knockouts, which have normal ATP7B function, suggesting that SCC is a normal metabolite carrying copper in the serum. In agreement with this hypothesis, partially purified SCC-Cu competes with free copper for uptake by Ctr1. Thus, hepatic down-regulation of Ctr1 allows switching to an SCC-mediated removal of copper via kidney when liver function is impaired. These results demonstrate that the body regulates copper export through more than one mechanism; better understanding of urinary copper excretion may contribute to an improved diagnosis and monitoring of WD.

  19. Urinary copper elevation in a mouse model of Wilson's disease is a regulated process to specifically decrease the hepatic copper load.

    Science.gov (United States)

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

    2012-01-01

    Body copper homeostasis is regulated by the liver, which removes excess copper via bile. In Wilson's disease (WD), this function is disrupted due to inactivation of the copper transporter ATP7B resulting in hepatic copper overload. High urinary copper is a diagnostic feature of WD linked to liver malfunction; the mechanism behind urinary copper elevation is not fully understood. Using Positron Emission Tomography-Computed Tomography (PET-CT) imaging of live Atp7b(-/-) mice at different stages of disease, a longitudinal metal analysis, and characterization of copper-binding molecules, we show that urinary copper elevation is a specific regulatory process mediated by distinct molecules. PET-CT and atomic absorption spectroscopy directly demonstrate an age-dependent decrease in the capacity of Atp7b(-/-) livers to accumulate copper, concomitant with an increase in urinary copper. This reciprocal relationship is specific for copper, indicating that cell necrosis is not the primary cause for the initial phase of metal elevation in the urine. Instead, the urinary copper increase is associated with the down-regulation of the copper-transporter Ctr1 in the liver and appearance of a 2 kDa Small Copper Carrier, SCC, in the urine. SCC is also elevated in the urine of the liver-specific Ctr1(-/-) knockouts, which have normal ATP7B function, suggesting that SCC is a normal metabolite carrying copper in the serum. In agreement with this hypothesis, partially purified SCC-Cu competes with free copper for uptake by Ctr1. Thus, hepatic down-regulation of Ctr1 allows switching to an SCC-mediated removal of copper via kidney when liver function is impaired. These results demonstrate that the body regulates copper export through more than one mechanism; better understanding of urinary copper excretion may contribute to an improved diagnosis and monitoring of WD.

  20. Diffusion of copper in porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Andsager, D.; Hetrick, J.M.; Hilliard, J.; Nayfeh, M.H. [Department of Physics, 1110 West Green Street, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    1995-05-01

    We present a study on the nature of diffusion of copper in {ital p}-type porous silicon. The diffusion of evaporated copper in porous silicon and deposition of metal ions in aqueous solution through the porous network was measured by monitoring the metal concentration depth profile as a function of time using Auger electron spectroscopy. We observed that increasing metal penetration from copper evaporated samples correlates with quenching of photoluminescence, in agreement with previous ion quenching results. We extracted a diffusion coefficient from Auger concentration depth profiles which was seven orders of magnitude lower than that expected for diffusion of copper in bulk crystalline Si at room temperature. Deposition of ionic species cannot be characterized as a simple diffusion process. The observed deposition rates were strongly dependent on the solution concentration.

  1. Synthesis, characterization and investigation of electrochemical and spectroelectrochemical properties of non-peripherally tetra-5-methyl-1,3,4-thiadiazole substituted copper(II) iron(II) and oxo-titanium (IV) phthalocyanines

    Science.gov (United States)

    Demirbaş, Ümit; Akyüz, Duygu; Akçay, Hakkı Türker; Barut, Burak; Koca, Atıf; Kantekin, Halit

    2017-09-01

    In this study novel substituted phthalonitrile (3) and non-peripherally tetra 5-Methyl-1,3,4-thiadiazole substituted copper(II) (4), iron(II) (5) and oxo-titanium (IV) (6) phthalocyanines were synthesized. These novel compounds were fully characterized by FT-IR, 1H NMR, UV-vis and MALDI-TOF mass spectroscopic techniques. Voltammetric and in situ spectroelectrochemical measurements were performed for metallo-phthalocyanines (4-6). TiIVOPc and FeIIPc showed metal-based and ligand-based electron transfer reactions while CuIIPc shows only ligand-based electron transfer reaction. Voltammetric measurements indicated that the complexes have reversible, diffusion controlled and one-electron redox reactions. The assignments of the redox processes and color of the electrogenerated species of the complexes were determined with in-situ spectroelectrochemical and electrocolorimetric measurements. These measurements showed that the complexes can be used as the electrochromic materials for various display technologies.

  2. Green synthesis, characterization and catalytic activity of natural bentonite-supported copper nanoparticles for the solvent-free synthesis of 1-substituted 1H-1,2,3,4-tetrazoles and reduction of 4-nitrophenol

    Directory of Open Access Journals (Sweden)

    Akbar Rostami-Vartooni

    2015-12-01

    Full Text Available In this study, Cu nanoparticles were immobilized on the surface of natural bentonite using Thymus vulgaris extract as a reducing and stabilizing agent. The natural bentonite-supported copper nanoparticles (Cu NPs/bentonite were characterized by FTIR spectroscopy, X-ray diffraction (XRD, X-ray fluorescence (XRF, field emission scanning electron microscopy (FE-SEM, energy dispersive X-ray spectroscopy (EDS, transmission electron microscopy (TEM, selected area electron diffraction (SAED and Brunauer–Emmett–Teller (BET analysis. Afterward, the catalytic performance of the prepared catalyst was investigated for the solvent-free synthesis of 1-substituted 1H-1,2,3,4-tetrazoles and reduction of 4-nitrophenol (4-NP in water. It was found that the Cu NPs/bentonite is a highly active and recyclable catalyst for related reactions.

  3. Flash light sintered copper precursor/nanoparticle pattern with high electrical conductivity and low porosity for printed electronics

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Wan-Ho; Hwang, Hyun-Jun [Department of Mechanical Convergence Engineering, Hanyang University, 17 Haendang-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, 17 Haendang-Dong, Seongdong-Gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2015-04-01

    In this work, the hybrid copper inks with precursor and nanoparticles were fabricated and sintered via flash light irradiation to achieve highly conductive electrode pattern with low porosity. The hybrid copper ink was made of copper nanoparticles and various copper precursors (e.g., copper(II) chloride, copper(II) nitrate trihydrate, copper(II) sulfate pentahydrate and copper(II) trifluoroacetylacetonate). The printed hybrid copper inks were sintered at room temperature and under ambient conditions using an in-house flash light sintering system. The effects of copper precursor weight fraction and the flash light irradiation conditions (light energy and pulse duration) were investigated. Surfaces of the sintered hybrid copper patterns were analyzed using a scanning electron microscope. Also, spectroscopic characterization techniques such as Fourier transform infrared spectroscopy and X-ray diffraction were used to investigate the crystal phases of the flash light sintered copper precursors. High conductivity hybrid