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    Immobilized copper(II) on nitrogen-rich polymer-entrapped Fe3O4 nanoparticles: A highly loaded and magnetically recoverable catalyst for aqueous click chemistry

    , Article Applied Organometallic Chemistry ; Volume 30, Issue 2 , 2016 , Pages 73-80 ; 02682605 (ISSN) Zohreh, N ; Hosseini, S. H ; Pour Javadi, A ; Bennett, C ; Sharif University of Technology
    John Wiley and Sons Ltd 
    Abstract
    A heterogeneous magnetic copper catalyst was prepared via anchoring of copper sulfate onto multi-layered poly(2-dimethylaminoethyl acrylamide)-coated magnetic nanoparticles and was characterized using various techniques. The catalyst was found to be active, effective and selective for one-pot three-component reaction of alkyl halide, sodium azide and alkyne, known as copper-catalyzed click synthesis of 1,2,3-triazoles. As little as 0.3 mol% of catalyst was found to be effective under the optimum conditions. The catalyst could also be recycled and reused up to seven times without significant loss of activity. Thermal stability, high loading level of copper on catalyst, broad diversity of... 

    Experimental and simulation investigation on separation of binary hydrocarbon mixture by thermogravitational column

    , Article Journal of Molecular Liquids ; Volume 268 , 2018 , Pages 791-806 ; 01677322 (ISSN) Hashemipour, N ; Karimi Sabet, J ; Motahari, K ; Mahruz Monfared, S ; Amini, Y ; Moosavian, M. A ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    In this article, experimental and numerical investigations are performed to study a thermogravitational column (TGC) for the separation of toluene/n-heptane mixture. This research has tried to determine the main significant parameters and their effects on the performance of the process. In experimental examinations, the influence of the main parameters such as feed flow rate, cut and temperature gradient on the performance of the TGC efficiency is studied. In addition, computational fluid dynamics is used to simulate the separation process in this review. The response surface methodology (RSM) was also applied to minimize the number of runs and investigate the optimum operating conditions.... 

    Optical concentration of gold nanoparticles as a new concept of analytical sensitivity

    , Article Instrumentation Science and Technology ; 2020 Vaziri Heshi, S ; Shokoufi, N ; Seyed Reihani, S. N ; Sharif University of Technology
    Bellwether Publishing, Ltd  2020
    Abstract
    Concentration procedures have always been implemented when trace analysis of compounds in real matrices is contemplated. A variety of concentration strategies have been reported aiming at decreasing the limits of detection (LODs). The optical concentration of the substance in solution is one of the novel concepts for the enhancement of the analytical sensitivity. In this study, the optical concentration has been measured by the trapping of gold nanoparticles ((Formula presented.) nm) dispersed in water at low-concentrations at the focal volume of the laser beam. The influence of factors such as the time of gold nanoparticle trapping, the size of the nanoparticles, the intensity of the laser... 

    Effect of graphene and process parameters on mechanical performance and electrical resistance of aluminum to copper friction stir joint

    , Article Materials Research Express ; Volume 6, Issue 4 , 2019 ; 20531591 (ISSN) Montazerian, M. H ; Movahedi, M ; Jondi, M. R ; Sharif University of Technology
    Institute of Physics Publishing  2019
    Abstract
    Effects of graphene, tool rotational speed and pass number were studied on the reliability and electrical resistance of the aluminum to copper friction stir welds. Addition of graphene was an effective solution to overcome the increase in the electrical resistance of the aluminum/copper joints. Indeed, presence of graphene decreased the electrical resistance of the joints to the values comparable with that of the copper base metal. However, joint tensile strength was not affected significantly by graphene. Decrease in the tool rotational speed improved the dispersion of the graphene particles and tensile strength, while reduced the electrical resistance. Tensile strength of the joint reached... 

    Determining and optimizing power loss reduction in distribution feeders due to Distributed generation

    , Article 2006 IEEE PES Power Systems Conference and Exposition, PSCE 2006, Atlanta, GA, 29 October 2006 through 1 November 2006 ; 2006 , Pages 1914-1918 ; 142440178X (ISBN); 9781424401789 (ISBN) Honarvar Nazari, M ; Parniani, M ; Sharif University of Technology
    2006
    Abstract
    One of the beneficial impacts of Distributed generation (DG) units on electrical network is power loss reduction in the distribution feeder on which DG is located. In this paper the effect of DG on power losses of a distribution feeder with a combination of uniformly distributed and lumped loads is investigated, and a mathematical model of power loss reduction as a function of DG and the feeder parameters is extracted. Then, based on the derived formula, optimum conditions of utilizing and locating the DG units are obtained. © 2006 IEEE  

    Phosphomolybdic acid/graphene oxide as novel green catalyst using for biodiesel production from waste cooking oil via electrolysis method: Optimization using with response surface methodology (RSM)

    , Article Fuel ; Volume 287 , 2021 ; 00162361 (ISSN) Helmi, M ; Tahvildari, K ; Hemmati, A ; Aberoomand azar, P ; Safekordi, A ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    In this study, biodiesel (FAME) was prepared using a novel heterogeneous catalyst of phosphomolybdic acid (H3PMo12O40, HPMo)/support graphene oxide (GO). The characterization of the catalyst was evaluated by SEM, EDX, Map analysis, TEM, FT-IR, and Raman analyses. The production of biodiesel from waste cooking oil (WCO) was carried out by the electrolysis method. The process of the trans-esterification reaction was optimized by applying the response surface methodology (RSM) based on the central composite design (CCD) approach. The effects of four independent variables of methanol to oil molar ratio (6–12 mol:mol), catalyst weight (0.5–1.5 wt%), time (8–24 h), and voltage (30–70 V) were... 

    Optimum operating conditions for direct oxidation of h 2s in a fluidized bed reactor

    , Article World Academy of Science, Engineering and Technology ; Volume 79 , 2011 , Pages 237-241 ; 2010376X (ISSN) Golestani, F ; Kazemeini, M ; Fattahi, M ; Amjadian, A ; Sharif University of Technology
    2011
    Abstract
    In this research a mathematical model for direct oxidization of hydrogen sulfide into elemental sulfur in a fluidized bed reactor with external circulation was developed. As the catalyst is deactivated in the fluidized bed, it might be placed in a reduction tank in order to remove sulfur through heating above its dew point. The reactor model demonstrated via MATLAB software. It was shown that variations of H 2S conversion as well as; products formed were reasonable in comparison with corresponding results of a fixed bed reactor. Through analyzing results of this model, it became possible to propose the main optimized operating conditions for the process considered. These conditions included;... 

    Alteration of corrosion and nanomechanical properties of pulse electrodeposited Ni/SiC nanocomposite coatings

    , Article Journal of Alloys and Compounds ; Vol. 598 , 2014 , Pages 236-242 ; ISSN: 09258388 Zarghami, V ; Ghorbani, M ; Sharif University of Technology
    Abstract
    Nickel/silicon carbide composite electrodeposits were prepared on a rotating disk electrode (RDE), under pulse current condition. The effect of pulse parameters, current density, SiC content in the electrolyte on the codeposition of SiC were studied. Afterwards, the effect of codeposited SiC amount was investigated on electrochemical behavior and nanomechanical properties of coatings. The coatings were analyzed with Scanning Electron Microscopy (SEM), linear polarization, nanoindentation and Atomic Force Microscopy (AFM). The Ni-SiC electrocomposites, prepared at optimum conditions, exhibited improved nanomechanical properties in comparison to pure nickel electrodeposits. With increasing... 

    Dme direct synthesis from syngas in a large-scale three-phase slurry bubble column reactor: transient modeling

    , Article Chemical Engineering Communications ; Vol. 201, issue. 5 , Nov , 2014 , pp. 612-634 ; ISSN: 00986445 Papari, S ; Kazemeini, M ; Fattahi, M ; Fatahi, M ; Sharif University of Technology
    Abstract
    In this research, a new transient mathematical model based upon tanks-in-series configuration was developed to simulate the direct synthesis of dimethyl ether (DME) from syngas in a commercial-scale slurry bubble column reactor. A comparison between the simulation results and experimental data showed that the applied model might acceptably describe the behavior of the slurry reactor. Furthermore, simulation results in the heterogeneous bubble flow regime indicated that the proposed model with 10 tanks-in-series provided the optimum condition. Utilizing this transient model and considering catalyst deactivation, the effect of operating conditions on DME productivity and CO conversion were... 

    Enhanced heavy oil recovery in sandstone cores using TiO2 nanofluids

    , Article Energy and Fuels ; Vol. 28, issue. 1 , 2014 , pp. 423-430 ; ISSN: 08870624 Ehtesabi, H ; Ahadian, M. M ; Taghikhani, V ; Ghazanfari, M. H ; Sharif University of Technology
    Abstract
    Anatase and amorphous TiO2 nanoparticles were used to improve recovery of heavy oil from sandstone cores. Before performing core floods, the stability of nanoparticles at different salinities was tested using ζ potential and ultraviolet-visible (UV-vis) methods. While water recovered only 49% of the oil in the core flood experiments, 0.01% anatase structure solution recovered 80% of the oil after injecting two pore volumes at optimum conditions. To understand the mechanism responsible for improved recovery, contact angle measurements were performed on the rock surface before and after treatment with the nanoparticle solution. Contact angle measurements showed that the rock wettability... 

    Electrophoretic deposition of Ni/SiO2 nanocomposite coating: Fabrication process and tribological and corrosion properties

    , Article Journal of Nano Research ; Volume 26 , 6 January , 2014 , Pages 45-51 ; ISSN: 16625250 Isfahani, A. G ; Ghorbani, M ; Sharif University of Technology
    Abstract
    To the best of our knowledge, this work presents the first successful effort to fabricate and study nanostructured Ni-based composite coatings using the electrophoretic deposition method with nanostructured SiO2 particles. In this work, Ni/SiO2 nanoparticle composite coatings were prepared by electrophoretic deposition (EPD) [1] and their hardness, wear and corrosion resistances [2] were examined. After studying the morphology of the coatings and finding the optimum conditions for uniform coating, in order to improve the mechanical properties as well as resistance to corrosion, sintering was performed. The Ni/SiO2 nanocomposite coatings show excellent hardness (∼376 HV), reduced Young's... 

    Reaction kinetics determination and neural networks modeling of methanol dehydration over nano γ-Al 2O 3 catalyst

    , Article Journal of Industrial and Engineering Chemistry ; Volume 18, Issue 6 , 2012 , Pages 2059-2068 ; 1226086X (ISSN) Alamolhoda, S ; Kazemeini, M ; Zaherian, A ; Zakerinasab, M. R ; Sharif University of Technology
    2012
    Abstract
    In this research nano γ-Al 2O 3 catalyst was synthesized through precipitation process then characterized and utilized for methanol dehydration reaction in a slurry batch reactor in route to the indirect synthesis of the dimethyl ether (DME). In this venue, effects of the key parameters on methanol conversion and catalyst stability were investigated. Moreover, the internal and external mass transfer resistances were eliminated; hence the intrinsic kinetics controlled the reaction. Therefore, the optimum conditions for temperature, methanol concentration, catalyst mass and stirrer speed were determined to be 300°C, 1.18mol/l, 1.5g and 1100rpm, respectively. Next, different reaction rate... 

    Using three different optical fiber designs to study humidity effect on the air refractive index

    , Article Optics and Lasers in Engineering ; Volume 50, Issue 11 , November , 2012 , Pages 1495-1500 ; 01438166 (ISSN) Golnabi, H ; Sharif University of Technology
    2012
    Abstract
    Design and operation of three different optical designs based on the light intensity modulation for investigation of the humidity effects on the air index of refraction are described. The measurement variable is the transmitted power, which depends on the refractive index of the medium in the path of a fiber-to-fiber optical design. Three different probes (probe #1, #2, and #3) are tested in which probe #1 and probe #2 can also check the presence of water or any other transparent liquid in the gap between the two axial fibers. Performances of the new systems are tested as a refractive index monitoring mean and experimental results are given. The variations of the modulated powers as... 

    Application of response surface methodology for optimization of paracetamol particles formation by RESS method

    , Article Journal of Nanomaterials ; Volume 2012 , 2012 ; 16874110 (ISSN) Karimi Sabet, J ; Ghotbi, C ; Dorkoosh, F ; Sharif University of Technology
    2012
    Abstract
    Ultrafine particles of paracetamol were produced by Rapid Expansion of Supercritical Solution (RESS). The experiments were conducted to investigate the effects of extraction temperature (313353K), extraction pressure (1018MPa), preexpansion temperature (363403K), and postexpansion temperature (273323 K) on particles size and morphology of paracetamol particles. The characterization of the particles was determined by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Liquid Chromatography/Mass Spectrometry (LC-MS) analysis. The average particle size of the original paracetamol was 20.8m, while the average particle size of paracetamol after nanonization via the... 

    Performances evaluation of Photo-Fenton process and Sonolysis for the treatment of Penicillin G formulation effluent

    , Article 1st 2011 International Conference on Environment Science and Biotechnology, ICESB 2011, Male, 25 November 2011 through 26 November 2011 ; Volume 8 , 2011 , Pages 202-208 ; 18780296 (ISSN) Saghafinia, M. S ; Emadian, S. M ; Vossoughi, M ; Sharif University of Technology
    Abstract
    Penicillin G is an active pharmaceutical ingredient of great importance in health sectors. Meanwhile, because of its huge quantity production and resistance to biodegradability, this antibiotic is ubiquitously presented in aquatic environment. In this study, the degradation of effluent wastewater from Penicillin G production plant by Photo- Fenton process and Ultrasound process (Sonolysis) was investigated, the effects of different process variables in both methods were evaluated and at last the degradation of Pen-G by these two processes in the optimum conditions was compared. Pen-G concentration and Chemical Oxygen Demand (COD) were selected as the environmental parameters to follow the... 

    A study of the water-gas shift reaction in Ru-promoted Ir-catalysed methanol carbonylation utilising experimental design methodology

    , Article Chemical Engineering Science ; Volume 66, Issue 20 , October , 2011 , Pages 4798-4806 ; 00092509 (ISSN) Hosseinpour, V ; Kazemeini, M ; Mohammadrezaee, A ; Sharif University of Technology
    2011
    Abstract
    The water-gas shift reaction occurs competitively to the main reaction of the Ir-catalysed methanol carbonylation process. To study the effect of seven factors including temperature, pressure, iridium, ruthenium, methyl iodide, methyl acetate and water concentrations on the formation of hydrogen and carbon dioxide as a result of the water-gas shift reaction and other side reactions in the carbonylation of methanol to acetic acid, the experimental design method combined with response surface methodology (RSM) was utilised. Central composite design at five levels (with α=1.63) was used to design experiments. A quadratic model that included the main and interaction effects of variables for H 2... 

    Determination of 2,4-D in environmental samples by three phases directly suspended LPME combined with HPLC-UV

    , Article Analytical Methods ; Volume 3, Issue 10 , 2011 , Pages 2261-2267 ; 17599660 (ISSN) Amani, V ; Roshan, S ; Asgharinezhad, A. A ; Najafi, E ; Abedi, H ; Tavassoli, N ; Lotfi Zadeh Zhad, H. R ; Sharif University of Technology
    Abstract
    Experimental design of directly suspended droplet liquid-liquid-liquid microextraction has been used to determine residue of 2,4-D, in environmental water samples. A free suspended droplet of 5.5 μL of receiving phase is delivered to the top-center position of 1-Octanol, which is an immiscible organic solvent, floating on the top of a 2.5 mL aqueous sample while being agitated by a stirring bar to create a mild vortex at the center of the vial. Central composite rotatable design has been used for studying the effect of the parameters, the factors interacting with each other and finding the optimum condition. The chromatographic separation was accomplished on a shim-Pak C18 column using a... 

    Investigation on the bond strength of Al-1100/St-12 roll bonded sheets, optimization and characterization

    , Article Materials and Design ; Volume 32, Issue 6 , 2011 , Pages 3143-3149 ; 02641275 (ISSN) Movahedi, M ; Kokabi, A. H ; Seyed Reihani, S. M ; Sharif University of Technology
    Abstract
    Al-1100/St-12 aluminum clad steel sheets were produced using roll bonding process at different reductions in thickness and with various supplemental annealing treatments. Experiments were conducted by applying the Taguchi method to obtain optimum condition for maximizing the joint strength. The joint strengths of the bi-layer sheets were evaluated by peel test. The Al/Fe intermetallic phases at the joint interface and the peeled surfaces were examined using scanning electron microscopy (SEM). Energy dispersive spectroscopy (EDS) and Vickers microhardness test were performed to characterize the intermetallic compounds. The results indicate that at the optimum condition of 0.50 reduction in... 

    Performance study of a supersonic inlet in the presence of a heat source

    , Article Scientia Iranica ; Volume 18, Issue 3 B , 2011 , Pages 375-382 ; 10263098 (ISSN) Soltani, M. R ; Farahani, M ; Sepahi Younsi, J ; Sharif University of Technology
    2011
    Abstract
    The flow over a supersonic inlet has been investigated experimentally and numerically at a free stream Mach number of 2 and a zero degree angle of attack. Wind tunnel tests were performed to obtain the performance parameters of the inlet and were used as a baseline and validation tools for the numerical code. A heat source was added to the flow field at a distance ahead of the inlet. The effect of heat source addition on the main performance parameters of the inlet is investigated numerically. Results show that the heat source considerably reduces drag coefficient; however, its effect on pressure recovery is not favorable. This unfavorable effect was then minimized by controlling heat source... 

    Optimum operating conditions for direct oxidation of H2S in a fluidized bed reactor

    , Article World Academy of Science, Engineering and Technology ; Volume 77 , 2011 , Pages 411-415 ; 2010376X (ISSN) Golestani, F ; Kazemeini, M ; Fattahi, M ; Amjadia, A ; Sharif University of Technology
    Abstract
    In this research a mathematical model for direct oxidization of hydrogen sulfide into elemental sulfur in a fluidized bed reactor with external circulation was developed. As the catalyst is deactivated in the fluidized bed, it might be placed in a reduction tank in order to remove sulfur through heating above its dew point. The reactor model demonstrated via MATLAB software. It was shown that variations of H 2S conversion as well as; products formed were reasonable in comparison with corresponding results of a fixed bed reactor. Through analyzing results of this model, it became possible to propose the main optimized operating conditions for the process considered. These conditions included;...