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    Micro-stratigraphical investigation on corrosion layers in ancient Bronze artefacts by scanning electron microscopy energy dispersive spectrometry and optical microscopy

    , Article Heritage Science ; Volume 1, Issue 1 , 2013 ; 20507445 (ISSN) Oudbashi, O ; Emami, S. M ; Ahmadi, H ; Davami, P ; Sharif University of Technology
    Background: Archaeological metallic artefacts buried in soils deteriorate by means of various environmental as well as internal factors and mechanisms over time such as change in composition and microstructure of metal and corrosive factors due to long-term burial environment. Corrosion in metals occurs in different morphologies and results in different types of corrosion products based on soil composition. Identification of corrosion mechanisms and morphology in archaeological metals can help conservators to characterize deterioration occurred in metals and make decisions to protect artefacts about preventing further deterioration. In archaeological bronzes, different layers may form on the... 

    Magnetic nanoparticles entrapped in the cross-linked poly(imidazole/imidazolium) immobilized Cu(ii): An effective heterogeneous copper catalyst

    , Article RSC Advances ; Volume 4, Issue 87 , 2014 , Pages 46418-46426 ; ISSN: 20462069 Pourjavadi, A ; Hosseini, S. H ; Zohreh, N ; Bennett, C ; Sharif University of Technology
    Anchoring of copper sulfate in layered poly(imidazole-imidazolium) coated magnetic nanoparticles provided a highly stable, active, reusable, high loading, and green catalyst for the click synthesis of 1,2,3-triazoles via a one-pot cycloaddition of alkyl halide, azide, and alkyne (Cu-A3C). The catalyst was characterized by FTIR, TGA, TEM, SEM, XRD, EDAX, VSM and AAS. High selectivity, broad diversity of alkyl/benzyl bromide/chloride and alkyl/aryl terminal alkynes, and good to excellent yields of products were obtained using 0.7 mol% catalyst. The catalyst was readily recovered and reused up to 6 times without significant loss of activity  

    Not completely innocent: how argon binding perturbs cationic copper clusters

    , Article Journal of Physical Chemistry A ; Volume 124, Issue 43 , 2020 , Pages 9004-9010 Jamshidi, Z ; Lushchikova, O. V ; Bakker, J. M ; Visscher, L ; Sharif University of Technology
    American Chemical Society  2020
    Argon is often considered as an innocent probe that can be attached and detached to study the structure of a particular species without perturbing the species too much. We have investigated whether this assumption also holds for small copper cationic clusters and demonstrated that small but significant charge transfer from argon to metal changes the remaining binding positions, leading in general, to weaker binding of other argon atoms. The exception is binding to just one copper ion, where the binding of the first argon facilitates the binding of the second. © 2020 American Chemical Society  

    Comparison of bioleaching ability of two native mesophilic and thermophilic bacteria on copper recovery from chalcopyrite concentrate in an airlift bioreactor

    , Article Hydrometallurgy ; Volume 80, Issue 1-2 , 2005 , Pages 139-144 ; 0304386X (ISSN) Mousavi, S. M ; Yaghmaei, S ; Vossoughi, M ; Jafari, A ; Hoseini, S. A ; Sharif University of Technology
    A mesophilic iron oxidizing bacterium, Acidithiobacillus ferrooxidans, has been isolated (33 °C) from a typical chalcopyrite copper concentrate of the Sarcheshmeh copper mine in the region of Kerman located in the south of Iran. In addition, a thermophilic iron oxidizing bacterium, Sulfobacillus, has been isolated (60 °C) from the Kooshk lead and zinc mine near the city of Yazd in central Iran. Effects of some variable parameters such as solids concentration, temperature and pH on the bioleaching of chalcopyrite obtained from Sarcheshmeh copper mine were investigated. Bioleaching experiments were carried out in two batch airlift bioreactors with a recycling stream. The results indicate that... 

    Microstructure and compressibility of SiC nanoparticles reinforced Cu nanocomposite powders processed by high energy mechanical milling [electronic resource]

    , Article Ceramics International ; Volume 40, Issue 1, Part A, January 2014, Pages 951–960 Akbarpour, M.R. (Mohammad Reza) ; Salahi, E ; Alikhani Hesari, F ; Simchi, A ; Kim, H. S ; Sharif University of Technology
    Cu/SiC nanocomposite powders with homogeneously distributed nanosize SiC particles were produced by high energy mechanical milling (MM). Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and micro-hardness and density measurements were performed to understand the effects of microstructure and hardness on compaction behavior during MM. The effects of SiC nanoparticle content and mechanical milling time on apparent density (AD) and tap density (TD) of the nanocomposite powders were systematically investigated. The Hausner ratio (HR), defined as TD to AD, were estimated to evaluate friction between the particles. Increasing MM duration and SiC content resulted... 

    H2S sensing properties of added copper oxide in WO3

    , Article Key Engineering Materials ; Volume 543 , March , 2013 , Pages 145-149 Nowrouzi, R. (Rasoul) ; Razi Astaraei, F. (Fatemeh) ; Kashani, Sh. (shima) ; Iraji Zad, A. (Azam) ; Sharif University of Technology
    We study Hydrogen sulfide gas detection properties of pure and 1% copper oxide added WO3 thin films. The spin coated deposits on alumina substrates were annealed at 500 C for 1 hour in order to improve the crystallinity of the films. The sensitivity of pure tungsten oxide is poor even at temperatures of about 100 C but the doped samples exhibit good response to H2S gas. Our data show sensitivity of about 1500 in 10 ppm diluted gas in air at 100 C. The films are sensitive to the gas even at 250 ppb (sensitivity about 2) H2S concentration at 100 C but with rather long recovery time. Crystal structure, morphology and chemical composition of samples were studied by X-Ray diffraction (XRD),... 

    Palladium and copper complexes with oxygen-nitrogen mixed donors as efficient catalysts for the Heck reaction

    , Article Inorganica Chimica Acta ; Volume 383 , 2012 , Pages 46-51 ; 00201693 (ISSN) Bagherzadeh, M ; Amini, M ; Ellern, A ; Keith Woo, L ; Sharif University of Technology
    A simple bidentate ligand, 2-(2′-hydroxyphenyl)-5,6-dihydro-1,3- oxazine, was readily prepared with a two-step synthesis. Two novel complexes of Pd(II) and Cu(II) with this (N,O) oxazine ligand have been prepared and the molecular structures of these complexes have been confirmed by X-ray structure analysis, NMR, IR and UV-Vis spectroscopy. These complexes efficiently catalyze the Heck reaction of aryl halides with olefins at 120 °C in 8 h. The reaction conditions for the Heck coupling of iodobenzene with styrene was optimized by varying the amount of the catalyst, reaction temperature, solvent and exogenous base  

    Photocatalytic properties of mesoporous TiO2 nanocomposites modified with carbon nanotubes and copper

    , Article Ceramics International ; 2016 ; 02728842 (ISSN) Nourbakhsh, A ; Abbaspour, S ; Masood, M ; Mirsattari, S. N ; Vahedi, A ; Mackenzie, K. J. D ; Sharif University of Technology
    Elsevier Ltd  2016
    The photocatalytic activity of mesoporous TiO2 modified by the addition of carbon nanotubes (CNTs) and Cu is reported. Nanocomposites of carbon nanotubes (CNTs) containing varying amounts of Cu were formed by treatment with Cu2+ then reduced to Cu0 using NaBH4 as the reducing agent. The mesoporous TiO2, synthesized by a sol-gel method from titanium isopropoxide, was combined with the CNT/Cu nanocomposites to form the photocatalysts which were characterized by XRD, SEM, TEM, FTIR, XPS and BET surface area analysis. The photocatalytic properties of the mesoporous TiO2 composites were studied by measuring the degradation of methyl orange (MO) which was optimal in the sample containing 20wt% of... 

    Determining the optimum heap height considering the irrigation rate and the slope of heap bed variations in miduk copper mine

    , Article Acta Physica Polonica A ; Volume 128, Issue 2 , 2015 , Pages 352-354 ; 05874246 (ISSN) Fallahfar, B ; Rahimi, E ; Mohaghegh, N ; Sharif University of Technology
    Polish Academy of Sciences  2015
    Determining an optimum height is remarked as one of the most important issues in heap designing and this is obtained by calculating the number and the height of heap lifts. Although the increase of lift height has benefits in heap leaching method from economic point of view, it will reduce the stability and make process problems such as low permeability. The current paper analyzes the effect of sulphuric acid irrigation on the strength parameters of Miduk oxide copper ores. In addition, the result of the process experiments have evaluated with different irrigation rates as well as variable conditions of permeability. From process view, approximately 75% of copper is recovered at irrigation... 

    Removal of toxic metal ions from sungun acid rock drainage using mordenite zeolite, graphene nanosheets, and a novel metal–organic framework

    , Article Mine Water and the Environment ; Volume 35, Issue 1 , 2016 , Pages 18-28 ; 10259112 (ISSN) Rahimi, E ; Mohaghegh, N ; Sharif University of Technology
    Springer Verlag  2016
    We evaluated the sorptive properties of mordenite zeolite (MOR), a copper terephthalate metal–organic framework (MOF), and graphene oxide (GO) and their potential use in treating acid rock drainage (ARD) containing Fe3+, Cu2+, Mn2+, Zn2+, Pb2+, and Cd2+ ions. MOR was prepared via a hydrothermal method, MOF was prepared via a solvothermal method, and few-layered GO nanosheets were synthesized using Hummers’ method. The aqueous contaminants were removed by chemico-physical sorption and ion exchange in batch tests. It proved possible to dramatically improve removal efficiency and sorptive capacity by optimizing experimental conditions. Magnetic MOF crystals were more efficient in removing... 

    Fabrication of a highly flexible and affordable transparent electrode by aligned u-shaped copper nanowires using a new electrospinning collector with convenient transferability

    , Article ACS Omega ; Volume 4, Issue 25 , 2019 , Pages 21260-21266 ; 24701343 (ISSN) Nikzad, M. J ; Mohamadbeigi, N ; Sadrnezhaad, Kh ; Mahdavi, M ; Sharif University of Technology
    American Chemical Society  2019
    By making aligned and suspended copper nanowires, a high performance, transferable, and flexible transparent electrode is reported. Indium tin oxide is often used in devices such as displays, solar cells, and touchscreens that require transparent and conductive plates. Because of problems such as brittleness, high cost, and environmental effects, this material is facing rivals, the most serious of which are metallic nanowire meshes, especially copper. We developed a simple technique which uses a U-shaped collector in the electrospinning process with three advantages including the enhancement of the figure of merit (which is related to the surface resistance Rs and the transmittance T) by... 

    Electro-oxidation of methanol on copper in alkaline solution

    , Article Electrochimica Acta ; Volume 49, Issue 27 , 2004 , Pages 4999-5006 ; 00134686 (ISSN) Heli, H ; Jafarian, M ; Mahjani, M. G ; Gobal, F ; Sharif University of Technology
    Elsevier Ltd  2004
    The electro-oxidation of methanol on copper in alkaline solutions has been studied by the methods of cyclic voltammetry, quasi-steady state polarization and chronoamperometry. It has been found that in the course of an anodic potential sweep the electro-oxidation of methanol follows the formation of CuIII and is catalysed by this species through a mediated electron transfer mechanism. The reaction also continues in the early stages of the reversed cycle until it is stopped by the prohibitively negative potentials. The process is diffusion controlled and the current-time responses follow Cottrellian behavior. The rate constants, turnover frequency, anodic transfer coefficient and the apparent... 

    Copper chloride/kieselguhr: An efficient catalyst for oxidation of thiols to disulfides by molecular oxygen or air

    , Article Journal of Chemical Research ; Issue 5 , 2004 , Pages 364-365 ; 03082342 (ISSN) Hashemi, M. M ; Karimi Jaberi, Z ; Ghazanfari, D ; Sharif University of Technology
    Scientific Reviews Ltd  2004
    Kieselguhr supported copper chloride catalyses the oxidation of thiols to disulfides in the presence of oxygen or air  

    A calculation of diffusion parameters for Cu/Ta and Ta/Si interfaces in Cu/Ta/Si(1 1 1) structure

    , Article Materials Science in Semiconductor Processing ; Volume 6, Issue 4 , 2003 , Pages 165-170 ; 13698001 (ISSN) Moshfegh, A. Z ; Akhavan, O ; Sharif University of Technology
    In this investigation, we have studied the elemental diffusion coefficients of the Cu/Ta and Ta/Si interfaces in the Cu/Ta/Si(1 1 1) structure. The diffusion parameters for Cu diffusion into the Ta barrier layer, Ta diffusion into the Si substrate and diffusion of Si atoms into the Ta layer have been calculated using conversion of RBS data to concentration-depth profile curves and the solution of Fick's equation based on a constant diffusing amount boundary conditions. Furthermore, by calculating grain boundary diffusion coefficients, we have estimated grain boundary slabs of the Ta layer at different temperatures. It was shown that, the width of grain boundary slabs in the Ta layer at 700°C... 

    Pr at Gd or Ba site in GdBa2Cu3O7: Appearance of superconductivity

    , Article Physical Review B - Condensed Matter and Materials Physics ; Volume 68, Issue 10 , 2003 ; 10980121 (ISSN) Mohammadizadeh, R ; Akhavan, M ; Sharif University of Technology
    Gd(Ba2-xPrx)Cu3O7+δ single phase polycrystalline samples with 0.0 < − x < − 1.0 were investigated for their structural and electronic properties. Due to the solubility limit, the 123 structure forms in the 0.0 < − x < −0.50 range; for x > −0.6, a decomposition of the perovskite-type phases occurs. For x=0.2, there is an orthorhombic-tetragonal phase transition, concurrent with a metal-insulator transition, which is evident in the normal state resistivity. For xc=0.35, the superconductor-insulator transition occurs. An unusual hump has been observed on the resistivity vs temperature curve of the samples for particular values of Pr doping. Based on the Rietveld refinement of the x-ray... 

    Iodide-selective electrode based on copper phthalocyanine

    , Article Electroanalysis ; Volume 14, Issue 23 , 2002 , Pages 1621-1628 ; 10400397 (ISSN) Shahrokhian, S ; Taghani, A ; Moattar, F ; Sharif University of Technology
    Copper phthalocyanine was used as ion carrier for preparing polymeric membrane selective sensor for detection of iodide. The electrode was prepared by incorporating the ionophore into plasticized poly(vinyl chloride) (PVC) membrane, coated on the surface of graphite electrode. This novel electrode shows high selectivity for iodide with respect to many common inorganic and organic anions. The effects of membrane composition, pH and the influence of lipophilic cationic and anionic additives and also nature of plasticizer on the response characteristics of the electrode were investigated. A calibration plot with near-Nernestian slope for iodide was observed over a wide linear range of five... 

    Synthesis, characterization, and comparison of two new copper(II)complexes containing Schiff-base and diazo ligands as new catalysts in CuAAC reaction

    , Article Inorganica Chimica Acta ; Volume 492 , 2019 , Pages 213-220 ; 00201693 (ISSN) Bagherzadeh, M ; Mahmoudi, H ; Ataie, S ; Hafezi-Kahnamouei, M ; Shahrokhian, S ; Bellachioma, G ; Vaccaro, L ; Sharif University of Technology
    Elsevier S.A  2019
    Two copper(II)complexes were synthesized through the reaction of Cu(OAc)2·H2O with a Schiff-base ligand (1-(((3,4-dichlorophenyl)imino)methyl)naphthalen-2-ol)and a diazo ligand (1-((3,4-dichlorophenyl)diazenyl)naphthalen-2-ol)in methanol. The complexes and ligands were characterized employing elemental analysis and electronic spectra. In addition, the ligands were fully characterized by using several 1D and 2D NMR techniques. Single crystal X-ray crystallography was also used for the characterization of some of these materials. Due to finding out the effect of Schiff-base and diazo ligands nature on the catalytic activity, the complexes were catalytically compared in one-pot azide-alkyne... 

    Abnormal grain growth in alumina dispersion-strengthened copper produced by an internal oxidation process

    , Article Scripta Materialia ; Volume 58, Issue 11 , 2008 , Pages 966-969 ; 13596462 (ISSN) Afshar, A ; Simchi, A ; Sharif University of Technology
    Cu-2.7 vol.% Al2O3 (15 nm) composite was synthesized by an internal oxidation and hot extrusion process. The grain growth at elevated temperatures was studied and compared with extruded copper powder. Abnormal grain growth via a mechanism analogous to that of site-saturated phase transformation was observed. The critical grain size for the abnormal growth was determined to be 1.1 ± 0.2 μm. The growth rate decreased with time until the grain size approaching a final value ranging from 7.9 to 13.3 μm depending on the temperature. © 2008 Acta Materialia Inc  

    Time dependence of the surface plasmon resonance of copper nanorods

    , Article Journal of Physics Condensed Matter ; Volume 19, Issue 44 , 2007 ; 09538984 (ISSN) Azarian, A ; Iraji zad, A ; Dolati, A ; Ghorbani, M ; Sharif University of Technology
    Copper nanorods have been synthesized by electrodeposition with different lengths in porous polycarbonate (PCT) membranes with a pore diameter of 50nm and a thickness of 4νm. The PCT membranes were dissolved in dichloromethane (CH2Cl2) and the solvent was replaced by methanol solutions. Extinction peaks at 587, 581 and 574nm were observed for the Cu nanorods with aspect ratio R = 6,8 and 10 in methanol, respectively. Polarization of the molecules of the medium around the wires changes the dielectric constant of the medium. Hence, the wavelength of the extinction peaks does not shows good agreement with calculations that were done on basis of Gans' theory with nominal dielectric constant of... 

    The effect of additives on anode passivation in electrorefining of copper

    , Article Chemical Engineering and Processing: Process Intensification ; Volume 46, Issue 8 , 2007 , Pages 757-763 ; 02552701 (ISSN) Ojaghi Ilkhchi, M ; Yoozbashizadeh, H ; Sadegh Safarzadeh, M ; Sharif University of Technology
    In copper electrorefining process, some additives are added to the electrolyte to improve the morphology of cathode deposits as well as the quality of products. In the present investigation, the effects of thiourea, glue and chloride ions (as additives) on the passivation of industrial copper anodes under high current densities have been reported. Experiments were conducted at 65 °C; using a synthetic electrolyte containing 40 g/l Cu2+ and 160 g/l H2SO4. Results obtained from chronopotentiometry experiments showed that increasing the concentration of chloride ion leads to increase in passivation time. The results also indicated that from a certain level on, namely 2 ppm, the increase in...