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    Construction of Pt nanoparticle-decorated graphene nanosheets and carbon nanospheres nanocomposite-modified electrodes: Application to ultrasensitive electrochemical determination of cefepime

    , Article RSC Advances ; Volume 4, Issue 15 , 2014 , Pages 7786-7794 ; ISSN: 20462069 Shahrokhian, S ; Hosseini Nassab, N ; Ghalkhani, M ; Sharif University of Technology
    Abstract
    A novel ultrasensitive modified electrode was fabricated with a graphene nanosheets and carbon nanospheres (GNS-CNS)-based nanocomposite film as a powerful platform. Pt nanoparticles (PtNPs) were simply electrodeposited onto the GNS-CNS-coated glassy carbon electrode creating a PtNPs/GNS-CNS hybrid nanocomposite modified electrode. Scanning electron microscopy, energy dispersive X-ray spectroscopy and linear sweep voltammetry (LSV) techniques were used for the characterization of the prepared modified electrode. The results of investigation of electrochemical response characteristics of cefepime (CP) revealed a considerable improvement in the oxidation peak current of CP on PtNPs/GNS-CNS/GCE... 

    Designing of CK45 carbon steel and aisi 304 stainless steel dissimilar welds

    , Article Materials Research ; Vol. 17, issue. 1 , Oct , 2014 , p. 106-114 ; 15161439 Pouraliakbar, H ; Hamedi, M ; Kokabi, A. H ; Nazari, A ; Sharif University of Technology
    Abstract
    Gas tungsten arc welding of CK45 and AISI304 stainless steel was performed through preparation of different types of samples using ER308L and ERNi-1 wires. Welded samples were studied by different techniques including optical metallography, scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction, hardness measurements and impact test. It was observed that in the buttered specimen, the structure of the weld metal was completely austenitic while the microstructure of unbuttered sample was duplex ferritic-austenitic. M23C6-type carbides were observed within the weld metal of both as-weld specimen types. Effects of different post-weld heat... 

    L10 FePt Nanoparticles Processing with Applied Magnetic Field

    , Article Journal of Inorganic and Organometallic Polymers and Materials ; Volume 23, Issue 4 , April , 2013 , Pages 881-887 ; 15741443 (ISSN) Sebt, S. A ; Khajehnezhad, A ; Dariani, R. S ; Akhavan, M ; Sharif University of Technology
    2013
    Abstract
    Due to the strong magnetic anisotropy energy, the L10 FePt nanocrystals are considered as one of promising candidates for magnetic recording media with ultrahigh densities. The surfaces of Si and SiO2 wafers have been covered by FePt nanoparticles (NPs) and heated at 600 °C for 1 h to form the L10 phase. Bonding of NPs with the SiO2 surface in the presence of magnetic field during annealing process controls the L10 FePt NPs size and their uniform surface distribution. In the presence of perpendicular magnetic field to the surface, the size of NPs obtains up to 30 nm with coercivity of 5.8 kOe and in parallel magnetic field, the NPs size reaches to 45 nm with coercivity of 2.9 kOe. These... 

    Morphology, rheology and mechanical properties of polypropylene/ethylene-octene copolymer/clay nanocomposites: Effects of the compatibilizer

    , Article Composites Science and Technology ; Volume 72, Issue 14 , 2012 , Pages 1697-1704 ; 02663538 (ISSN) Bagheri Kazemabad, S ; Fox, D ; Chen, Y ; Geever, L. M ; Khavandi, A ; Bagheri, R ; Higginbotham, C. L ; Zhang, H ; Chen, B ; Sharif University of Technology
    Elsevier  2012
    Abstract
    The objective of this study was to investigate the effects of two compatibilizers, namely maleated polypropylene (PP-g-MA) and maleic anhydride grafted poly (ethylene-co-octene) (EOC-g-MA), on the morphology and thus properties of ternary nanocomposites of polypropylene (PP)/ethylene-octene copolymer (EOC)/clay nanocomposite. In this regard the nanocomposites and their neat polymer blend counterparts were processed twice using a twin screw extruder. X-ray diffraction, transmission electron microscopy, Energy dispersive X-ray spectroscopy, and scanning electron microscopy were utilized to characterize nanostructure and microstructure besides mechanical and rheological behaviors of the... 

    Study of the effect of frequency in pulse electrodeposition on Au-Ni from cyanide-citrate electrolyte by the aim of design of experiment

    , Article Advanced Materials Research, 15 December 2011 through 18 December 2011 ; Volume 410 , December , 2012 , Pages 377-381 ; 10226680 (ISSN) ; 9783037853160 (ISBN) Moakhar, R. S ; Imanieh, I ; Ghorbani, M ; Dolati, A ; Sharif University of Technology
    Abstract
    The aim of this paper is to study the influence of frequency in pulse electrodeposition, on the current efficiency, Ni content and surface morphology of deposits from a novel cyanide-citrate electrolyte with 20 mM gold as KAu(CN) 2 and 7 mM NiSO 4, with the aim of design of experiment by respond surface method (RSM). Frequency was in the range of 1-200 Hz in constant average current density, temperature, and duty cycle of 7 mA/cm 2, 59 °C and 55% respectively. Composition of the deposits was determined by atomic absorption spectroscopy (AAS). Additionally, deposits were characterized by scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDS). It was shown that from... 

    Densification and microstructural evolution during laser sintering of A356/SiC composite powders

    , Article Journal of Materials Science ; Volume 46, Issue 5 , 2011 , Pages 1446-1454 ; 00222461 (ISSN) Simchi, A ; Godlinski, D ; Sharif University of Technology
    Abstract
    This article reports experimental results on laser sintering of A356 aluminum alloy and A356/SiC composite powders. Effects of scan rate, sintering atmosphere, hatch spacing, and SiC volume fraction (up to 20%), and particle size (7 and 17 μm) on the densification were studied. The phase formation and microstructural development were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). Laser sintering under argon atmosphere exhibited higher densification compared to nitrogen. A faster sintering kinetics was observed as the scan rate decreased. Except at a low SiC content (5 vol%), the composite powders exhibited... 

    Effects of different operating parameters on the particle size of silver chloride nanoparticles prepared in a spinning disk reactor

    , Article Applied Physics A: Materials Science and Processing ; Volume 120, Issue 1 , July , 2015 , Pages 105-113 ; 09478396 (ISSN) Dabir, H ; Davarpanah, M ; Ahmadpour, A ; Sharif University of Technology
    Springer Verlag  2015
    Abstract
    The aim of this research was to present an experimental method for large-scale production of silver chloride nanoparticles using spinning disk reactor. Silver nitrate and sodium chloride were used as the reactants, and the protecting agent was gelatin. The experiments were carried out in a continuous mode by injecting the reactants onto the surface of the spinning disk, where a chemical precipitation reaction took place to form AgCl particles. The effects of various operating variables, including supersaturation, disk rotational speed, reactants flow rate, disk diameter, and excess ions, on the particle size of products were investigated. In addition, the AgCl nanoparticles were... 

    Hydrogen failure sensitivity of A516-Gr70 and API 5L-X70 steels in sour environments

    , Article Anti-Corrosion Methods and Materials ; Volume 62, Issue 5 , 2015 , Pages 294-300 ; 00035599 (ISSN) Taheri, H ; Dolati, A ; Beidokhti, B ; Sharif University of Technology
    Emerald Group Publishing Ltd  2015
    Abstract
    Purpose – This paper aims to clarify the corrosion behavior of two famous structural steels in sour environment. These steels have a vast application in oil and gas industries. The study aims to find the effect of different concentrations of sour solution on the origin of crack in these steels. Design/methodology/approach – After preparation of specimens, different sour solutions were made using the synthetic brine (according to National Association of Corrosion Engineers [NACE], Technical Committee Report 1D182) and various amounts of Na2S.9H2O and CH3COOH. The polarization test was done by Potansiostat apparatus model Zahner-IM6 at two temperatures, 25°C... 

    Spark plasma sintering of a multilayer thermal barrier coating on Inconel 738 superalloy: Microstructural development and hot corrosion behavior

    , Article Ceramics International ; Volume 42, Issue 2 , 2016 , Pages 2770-2779 ; 02728842 (ISSN) Pak Seresht, A. H ; Javadi, A. H ; Bahrami, M ; Khodabakhshi, F ; Simchi, A ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    In the present work, spark plasma sintering (SPS) process was employed to prepare a nanostructured yttria-stabilized zirconia (8YSZ) coating on a nickel-based superalloy (INCONEL 738) with functionally graded structure. A stack layer of INCONEL 738/NiCrAlY powder/Al foil/NiCrAlY+YSZ powder/YSZ powder was SPSed in a graphite die at an applied pressure of 40 MPa under an vacuum atmosphere (8 Pa). The sintering temperature was ∼1040 °C. For comparison purpose, the air plasma spray (APS) technique was employed to prepare the thermal barrier coating (TBC). Microstructural studies by scanning electron microscopy showed that the SPSed coating was sound and free of interfacial cracks and large... 

    Copper immobilized onto polymer-coated magnetic nanoparticles as recoverable catalyst for 'click' reaction

    , Article Applied Organometallic Chemistry ; 2016 ; 02682605 (ISSN) Banan, A ; Bayat, A ; Valizadeh, H ; Sharif University of Technology
    John Wiley and Sons Ltd  2016
    Abstract
    Copper supported on polymer-coated magnetic nanoparticles was designed and synthesized as a separable heterogeneous catalyst. The catalyst was fully characterized using several techniques such as Fourier transform infrared and energy-dispersive X-ray spectroscopies, scanning and transmission electron microscopies, X-ray diffraction, vibrating sample magnetometry, thermogravimetric analysis and inductively coupled plasma atomic emission spectrometry. All results showed that copper was successfully supported on the polymer-coated magnetic nanoparticles. Also, results showed that the synthesized material can be used as an efficient catalyst for the preparation of a series of 1,4-disubstituted... 

    Deposition of metallic molybdenum thin films on 304L steel substrate by SUT-PF

    , Article Surface and Coatings Technology ; 2016 ; 02578972 (ISSN) Hosseinzadeh, A ; Nazmabadi, M ; Vosoughi, N ; Sharif University of Technology
    Elsevier B. V 
    Abstract
    The present research work aims to employ plasma focus in order to deposit molybdenum (Mo) on the 304 stainless steel substrate. The processing parameters were shot numbers as well as the distance of substrate from the anode tip. Stereo, atom force microscopy (AFM) and field emission-scanning electron microscopy (FE-SEM) equipped with energy dispersive X-ray spectroscopy (EDS) were used to study the deposited coatings. Microhardness measurements were also performed on the coatings. Results indicated that the plasma focus can be successfully applied to deposit Mo anode on the stainless steel substrate. The coatings contained discrete pores with sizes varying by processing parameters. The... 

    Ugi four-component assembly process: An efficient approach for one-pot multifunctionalization of nanographene oxide in water and its application in lipase immobilization

    , Article Chemistry of Materials ; Volume 28, Issue 9 , 2016 , Pages 3004-3016 ; 08974756 (ISSN) Rezaei, A ; Akhavan, O ; Hashemi, E ; Shamsara, M ; Sharif University of Technology
    American Chemical Society  2016
    Abstract
    Graphene-based materials are revealing the leading edge of advanced technology for their exceptional physical and chemical properties. Chemical manipulation on graphene surface to tailor its unique properties and modify atomic structures is being actively pursued. Therefore, the discovery of robust and general protocols to anchor active functionality on graphene basal plane is still of great interest. Multicomponent reactions promise an enormous level of interest due to addressing both diversity and complexity in combinatorial synthesis, in which more than two starting compounds react to form a product derived from entire inputs. In this article, we present the first covalent... 

    Investigation on corrosion stratigraphy and morphology in some iron age bronze alloys vessels by OM, XRD and SEM–EDS methods

    , Article Applied Physics A: Materials Science and Processing ; Volume 122, Issue 4 , 2016 ; 09478396 (ISSN) Oudbashi, O ; Hasanpour, A ; Davami, P ; Sharif University of Technology
    Abstract
    The recently study of the corrosion in some bronze artefacts from the Sangtarashan Iron Age site, western Iran, was established to identify corrosion morphology and mechanism in these objects. The corrosion layers in 22 samples were studied by optical microscopy, scanning electron microscopy–energy-dispersive X-ray spectroscopy and X-ray diffraction methods. The results showed that a thin corrosion crust has formed on the surface of bronzes with a triple-layer structure, including two internal and one external corrosion layers. The formation of these layers is due to copper leaching from the bronze surface. The internal corrosion part has been a compact, tin-rich corrosion/oxidation product... 

    Copper immobilized onto polymer-coated magnetic nanoparticles as recoverable catalyst for ‘click’ reaction

    , Article Applied Organometallic Chemistry ; Volume 31, Issue 5 , 2017 ; 02682605 (ISSN) Banan, A ; Bayat, A ; Valizadeh, H ; Sharif University of Technology
    Abstract
    Copper supported on polymer-coated magnetic nanoparticles was designed and synthesized as a separable heterogeneous catalyst. The catalyst was fully characterized using several techniques such as Fourier transform infrared and energy-dispersive X-ray spectroscopies, scanning and transmission electron microscopies, X-ray diffraction, vibrating sample magnetometry, thermogravimetric analysis and inductively coupled plasma atomic emission spectrometry. All results showed that copper was successfully supported on the polymer-coated magnetic nanoparticles. Also, results showed that the synthesized material can be used as an efficient catalyst for the preparation of a series of 1,4-disubstituted... 

    Structural and corrosion characterization of hydroxyapatite/zirconium nitride-coated AZ91 magnesium alloy by ion beam sputtering

    , Article Applied Surface Science ; Volume 401 , 2017 , Pages 172-180 ; 01694332 (ISSN) Kiahosseini, S. R ; Afshar, A ; Mojtahedzadeh Larijani, M ; Yousefpour, M ; Sharif University of Technology
    Abstract
    The adhesion of hydroxyapatite (HA) as a coating for the AZ91 magnesium alloy substrate can be improved by using the sputtering method and an intermediate layer, such as ZrN. In this study, HA coatings were applied on ZrN intermediate layers at a temperature of 300 °C for 180, 240, 300, 360, and 420 min by ion beam sputtering. A profilometer device was used to study the HA coating thickness, which changed from 2 μm for the 180-min deposition to 4.7 μm for 420-min deposition. The grazing incidence X-ray diffraction analysis method and the Williamson–Hall analysis were used for structural investigation. As the deposition time increased, the crystalline size increased from 50 nm to 690 nm.... 

    Monodentate palladium(0)-[60]fullerene complexes of diphosphine ligands as efficient and sustainable nanocatalysts for the Mizoroki-Heck coupling reaction of aryl chlorides

    , Article New Journal of Chemistry ; Volume 41, Issue 18 , 2017 , Pages 9701-9709 ; 11440546 (ISSN) Sabounchei, S. J ; Hosseinzadeh, M ; Zarepour Jevinani, M ; Ghanbari, B ; Sharif University of Technology
    Royal Society of Chemistry  2017
    Abstract
    Two mononuclear coordination complexes of fullerene[60] with Pd(dba)2 (dba = dibenzylideneacetone), [(η2-C60)Pd(Ph2P(CH2)2PPh2C(H)C(O)R)2] (R = C10H7 (1), C6H4Cl (2)), have been prepared using a simple procedure to explore new directions in palladium catalysis and nanocarbon chemistry. The palladium(0)-[60]fullerene complexes incorporating unsymmetrical phosphorus ylides have been characterized by 1H, 13C and 31P NMR spectroscopic methods and other conventional techniques such as IR, TGA, SEM, ICP-OES, EDX and TEM analysis. Attributed to the enhanced dispersity and uniform size of the Pd nanoparticles with phosphine-functionalized fullerenes, the prepared catalysts exhibited comparable... 

    Effect of angular position on the quality of dense plasma focus-based additive layer manufactured molybdenum coatings

    , Article International Journal of Advanced Manufacturing Technology ; Volume 99, Issue 9-12 , 2018 , Pages 2717-2725 ; 02683768 (ISSN) Fereiduni, E ; Hosseinzadeh, A ; Nazmabadi, M ; Vosoughi, N ; Sharif University of Technology
    Springer London  2018
    Abstract
    The present research aims at depositing molybdenum on stainless steel substrate using dense plasma focus (DPF) device. The varying parameter was the angular position of substrate surface from the anode tip. The deposited layers were characterized using various analyses such as X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and microhardness measurements. Microstructural observations revealed that the deposited coatings had rough surfaces containing holes as well as a stripe-featured structure covering the whole surface including the interior regions of the holes and the regions among them.... 

    Gold-Decorated 3D 2,6-diaminopyridine network: a robust catalyst for the bromination of aromatic compounds

    , Article Industrial and Engineering Chemistry Research ; Volume 57, Issue 37 , 2018 , Pages 12314-12322 ; 08885885 (ISSN) Pourjavadi, A ; Keshavarzi, N ; Hosseini, S. H ; Matloubi Moghaddam, F ; Sharif University of Technology
    American Chemical Society  2018
    Abstract
    This article reports the synthesis of a magnetic heterogeneous catalyst through the decoration of gold ions onto the cross-linked polymeric nanocomposite from 2,6-diaminopyridine. The activity of the resulting catalyst was then evaluated in the bromination of aromatic compounds. The nitrogen rich support showed a high affinity to gold ions, and the measured content of Au was 0.76 mmol g-1. The structure of the catalyst was fully characterized by using Fourier-transform infrared spectroscopy, thermogravimetric analysis, atomic absorption spectroscopy, transmission electron microscopy, scanning electron microscope, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller surface area... 

    Ternary nanostructures of Cr2O3/graphene oxide/conducting polymers for supercapacitor application

    , Article Journal of Electroanalytical Chemistry ; Volume 823 , 2018 , Pages 505-516 ; 15726657 (ISSN) Asen, P ; Shahrokhian, S ; Iraji Zad, A ; Sharif University of Technology
    Abstract
    In this work, nanostructured composites of Cr2O3-graphene oxide (Cr2O3/GO) with conducting polymers; polyaniline (PANI) and polypyrrole (PPy) with the shape of cauliflower were synthesized via s simple and low cost one-step chronoamperometry method. The structures and morphologies of the resulting ternary nanocomposites were characterized by using Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The electrochemical capacitive properties of the prepared nanocomposites were evaluated by using cycle voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The... 

    Cyclic oxidation characteristics of HVOF thermal-sprayed NiCoCrAlY and CoNiCrAlY coatings at 1000 °C

    , Article Journal of Alloys and Compounds ; Volume 746 , 25 May , 2018 , Pages 509-519 ; 09258388 (ISSN) Feizabadi, A ; Salehi Doolabi, M ; Sadrnezhaad, S. K ; Rezaei, M ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Thermal-sprayed MCrAlY coatings have become widespread in various industries such as power plants, aeronautics, and oil and gas firms. High-temperature oxidation behavior of these coatings is therefore of significance. Spraying of two prevalent MCrAlY powders (NiCoCrAlY and CoNiCrAlY) on Hastelloy substrate by high velocity oxygen and fuel method and exposing them to 1000 °C air for resolving of their cyclic oxidation behavior are presented in this paper. The coatings were characterized by x-ray diffraction, scanning electron microscopy and energy-dispersive x-ray spectroscopy. The obtained oxidation kinetic indicated that at 1000 °C, the thermally sprayed NiCoCrAlY coating has greater...