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    Investigation of ionic liquids based on pyridinium and imidazolium as interfacial tension reducer of crude Oil−water and their synergism with MgCl2

    , Article Journal of Petroleum Science and Engineering ; Volume 171 , 2018 , Pages 414-421 ; 09204105 (ISSN) Lashkarbolooki, M ; Ayatollahi, S ; Sharif University of Technology
    Abstract
    Ionic liquids (ILs) can be tailored as chemical surfactants and surface active agents to reduce the interfacial tension (IFT) of crude oil/aqueous solutions for enhanced oil recovery processes. The current investigation was aimed to explore the nature of ingenious active agents in crude oil, including asphaltene and resin, and their possible interactions with two families of ILs, namely pyridinium and imidazolium, on the IFT of crude oil/aqueous solutions, both in the presence and absence of MgCl2. To the best of our knowledge, the effect of crude oil type on the IFT of crude oil/aqueous solution containing salts and IL has not been ever investigated. Accordingly, IFTs of light, medium and... 

    Mesoporous nanostructured Ni/MgAl2O4 catalysts: Highly active and stable catalysts for syngas production in combined dry reforming and partial oxidation

    , Article International Journal of Hydrogen Energy ; Volume 44, Issue 21 , 2019 , Pages 10427-10442 ; 03603199 (ISSN) Jalali, R ; Nematollahi, B ; Rezaei, M ; Baghalha, M ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    In this paper, the combination of dry reforming and partial oxidation of methane on nickel catalysts supported on mesoporous MgAl2O4 was investigated. The support was prepared by a facile sol-gel route using propylene oxide as a gelation agent. The characterizations of the catalysts were performed by BET, XRD, TPR, TPO, TPH, UV–vis, CO-dispersion, SEM and TEM techniques. In addition, the effects of nickel content, reaction and reduction temperatures, feed ratio and the GHSV value on the physicochemical and catalytic properties were studied. The results revealed that the nickel content had an optimum value of 7.5 wt% and the catalyst with this content of nickel exhibited the highest activity.... 

    Swelling behavior of heavy crude oil during injection of carbonated brine containing chloride anion

    , Article Journal of Molecular Liquids ; Volume 276 , 2019 , Pages 7-14 ; 01677322 (ISSN) Lashkarbolooki, M ; Zeinolabedini Hezave, A ; Ayatollahi, S ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Carbonated brine (CB) injection, known as one of the effective enhanced oil recovery processes, is highly dependent on the reservoir conditions (i.e. temperature and pressure) as well as the type of dissolved salt in aqueous solution. This study is aimed to investigate the influential parameters on the swelling of crude oil as the most important mechanism during CB injection. The swelling of crude oil in the presence of different CB solutions consisted of different salts such as KCl, NaCl, CaCl2 and MgCl2 with constant concentration of 15,000 ppm is studied using a high-pressure, high-temperature visual cell which measures the volume of drop using image processing software based on... 

    Effect of salts and their interaction with ingenious surfactants on the interfacial tension of crude oil/ionic solution

    , Article Chinese Journal of Chemical Engineering ; Volume 28, Issue 1 , January , 2020 , Pages 224-235 Lashkarbolooki, M ; Parvizi, R ; Ayatollahi, S ; Ghaseminejad Raeeni, E ; Sharif University of Technology
    Chemical Industry Press  2020
    Abstract
    Understanding the roles of asphaltene and resin as natural surfactants existed in crude oil can enlighten contradicting reported results regarding interfacial tension (IFT) of crude oil/aqueous solution as a function of salinity and ion type. In this way, this study is aimed to investigate the effect of these natural surface active agents on IFT of with special focus on SO42− anion and Mg2+ cation. Two different synthetic oil solutions of 8 wt% of the extracted asphaltene and resin dissolved in toluene are prepared, and then IFT values are measured. After that, the obtained results are compared with the IFT of intact crude oil in contact with the same saline solutions examined in the... 

    Adsorptive desulfurization of wild naphtha using magnesium hydroxide-coated ceramic foam filters in pilot scale: Process optimization and sensitivity analysis

    , Article Chemical Engineering and Processing - Process Intensification ; Volume 152 , 2020 Salehi, E ; Askari, M ; Afshar, S ; Eidi, B ; Aliee, M. H ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    Ultra-deep desulfurization for production of clean fuels is of great significance from environmental outlook. In this paper, adsorptive desulfurization (ADS) of wild naphtha was investigated in pilot scale using Mg(OH)2-impregnated aluminosilicate ceramic foam filters (ASCFs) as adsorbent. Effects of four operating parameters including temperature, pressure, adsorption bed length and initial sulfur concentration on sulfur removal efficiency of the process were studied via central composite design of experiment methodology. Sobol's sensitivity analysis was employed to quantitatively determine the impacts of the operating parameters on the removal performance of the separation system. The... 

    The dependency of optical properties on density for hot pressed MgF2

    , Article Infrared Physics and Technology ; Volume 51, Issue 6 , 2008 , Pages 546-549 ; 13504495 (ISSN) Nofar, M ; Madaah Hosseini, H. R ; Asghari Shivaee, H ; Sharif University of Technology
    2008
    Abstract
    The effects of the most important parameters of hot pressing, including temperature, time and pressure on densification, microstructure and infrared transparency of MgF2 ceramics are discussed. The results show that the absorption or scattering of incident radiation is strongly dependent on the amount of porosity. By increasing the temperature or the pressure, transparency at infrared wavelengths has been increased due to the rise in density. For the longer hot pressing times, a continuous increase in density and infrared transparency has been seen as well. Cold pressing before hot press has minor effects on the density and infrared transparency of MgF2. © 2008 Elsevier B.V. All rights... 

    Structural, magnetic and dielectric properties of Dy-Co substituted Sr-Ba-Mg-based magnetic oxides

    , Article Applied Physics A: Materials Science and Processing ; Volume 127, Issue 11 , 2021 ; 09478396 (ISSN) Lodhi, M. Y ; Khan, M. A ; Majeed, A ; Akhtar, M. N ; Ahmad, M ; Hussain, A ; Islam, M ; Nasar, G ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Abstract
    In present research six samples of nano X-type hexagonal ferrites with general formula SrBaMg2-xCoxDyyFe28-yO46 (x = 0–1; y = 0–0.1 with step size of 0.2 and 0.02, respectively) were synthesized by sol–gel technique. The temperature required for the phase formation of these materials was estimated using thermogravimetric analysis. X-ray diffraction patterns revealed the pure phase of the prepared materials up to the doping concentration of x = 0.4, y = 0.04 along with the second phase for higher doping concentration. The secondary phase appeared due to the solubility limit of higher ionic radius Dy3+ ions into the hexagonal lattice. The mean crystalline size decreased from 29 to 18 nm while... 

    Synthesis mechanism and microstructure characterization of ZrB2–ZrC–SiC nanocomposite synthesized via magnesium boro/carbothermal reduction at low temperatures

    , Article Materials Chemistry and Physics ; Volume 280 , 2022 ; 02540584 (ISSN) Jafari, S ; Bavand Vandchali, M ; Mashhadi, M ; Nemati, A ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    In this study, magnesium boro/carbothermal reduction of zirconium silicate (ZrSiO4) was employed to synthesize zirconium-based composite nanopowders of ZrB2–SiC, ZrB2–ZrC–SiC, ZrC–SiC, and ZrC. For this aim, three different temperatures of 1200 °C, 1300 °C, and 1450 °C were selected as the supposed temperatures for synthesis. Elemental Mg and NaCl were also selected to assist reduction process. In addition, effects of different C/Zr ratios as well as using elemental boron and B4C as two different boron sources were investigated on the final produced phases. Subsequently, XRD and SEM/EDS analyses were carried out to elaborate microstructure and phase studies. Finally, STA carried out up to... 

    Novel in-line effective fiber polarizer based on chromium and gold nano metal films: design and experiment

    , Article Laser Physics ; Volume 27, Issue 1 , 2017 ; 1054660X (ISSN) Yahyaei, B ; Panahi, O ; Malekmohamadi, S ; Mousavi, M ; Mardiha, M ; Kheyrollahi, M ; Sharif University of Technology
    Abstract
    The performance of the magnesium fluoride/chromium/gold in-line fiber optic polarizer on the thickness of magnesium fluoride buffer layer and chromium metal thin film was theoretically investigated. To prove the theoretical study, the magnesium fluoride/chromium/gold polarizer was made based on the simulation results. The obtained polarizer showed an extinction ratio of about 40 dB which is in a good agreement with the theoretical result at the corresponding thicknesses. Both theoretical and experimental results showed that by covering the side polished single mode fiber with the optimum layer thicknesses, a novel and an efficient fiber polarizer with the high extinction ratio could be... 

    Investigating injection of low salinity brine in carbonate rock with the assist of works of cohesion and adhesion and spreading coefficient calculations

    , Article Journal of Petroleum Science and Engineering ; Volume 161 , 2018 , Pages 381-389 ; 09204105 (ISSN) Lashkarbolooki, M ; Ayatollahi, S ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    Low salinity (LS) and smart water (SW) flooding processes which receive a great interest as cost-effective and environmental friendly techniques are relatively new enhanced oil recovery methods. Although shifting carbonate surfaces towards a water-wet state is the main mechanism behind these methods, effects of controlling factors (for instance: ion type or salinity) are already remained unsettled. In this regard, the effects of sulfate ion types (i.e. Na2SO4, MgSO4 and CaSO4) and their concentrations (i.e. 0–45,000 ppm) on wettability alteration are investigated using contact angle (CA) measurement technique. In addition, work of cohesion, work of adhesion and spreading coefficient of all... 

    Production of renewable hydrogen through aqueous-phase reforming of glycerol over Ni/Al2O3–MgO nano-catalyst

    , Article International Journal of Hydrogen Energy ; Volume 43, Issue 2 , 2018 , Pages 614-621 ; 03603199 (ISSN) Bastan, F ; Kazemeini, M ; Larimi, A ; Maleki, H ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    In this study, a series of Ni nano-catalysts supported on Al2O3 and MgO were prepared through the co-precipitation technique. Effects of the Al/Mg ratio on physicochemical characteristics of Ni/Al2O3–MgO catalysts were examined. Moreover, catalytic performance was investigated in order to determine the optimum catalyst for H2 production in aqueous phase reforming (APR) of glycerol. It was revealed that, the APR activity of synthesized catalysts strongly depended on the aforementioned ratio. In addition, it was observed that, the catalytic activity of Ni/MgO and Ni/Al2O3 samples were both lower than that of the corresponding mixed oxide supports. Furthermore, it was shown that, amongst the... 

    Effect of precipitation hardening heat treatment on mechanical and microstructure features of dissimilar friction stir welded AA2024-T6 and AA6061-T6 alloys

    , Article Journal of Manufacturing Processes ; Volume 31 , 2018 , Pages 214-220 ; 15266125 (ISSN) Karami Pabandi, H ; Jashnani, H. R ; Paidar, M ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    The friction stir welding of AA2024-T6 to AA6061-T6 plates with a 4 mm thickness has been studied at constant traverse and rotational speeds of 1000 rpm and 100 mm/min, respectively. The position of alloys and the effects of precipitation hardening heat treatment in retreating and advancing side in the friction stir welding were analyzed. The tool with taper threaded pin was used for welding. Macro and microstructural analysis were investigated by using Optical and Field Emission-Scanning Electron Microscopes (FE-SEM) to check out the welded joints. Micro-hardness and Tensile tests were also done to study mechanical attributes of the joints. Microstructural analysis revealed some grain... 

    A comprehensive study of basalt fiber reinforced magnesium phosphate cement incorporating ultrafine fly ash

    , Article Composites Part B: Engineering ; Volume 168 , 2019 , Pages 204-217 ; 13598368 (ISSN) Ahmad, M. R ; Chen, B ; Yu, J ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    This study investigated the influence of ultrafine fly ash (FA) on the mechanical properties, elevated temperature resistance and water stability of basalt fiber reinforced magnesium phosphate cement, and synergy mechanism was examined with the help of X-ray diffraction (XRD), thermogravimetric analysis (TGA), mercury intrusion porosimeter (MIP) and scanning electron microscopy energy dispersive spectroscopy (SEM/SEM-EDS) analysis techniques. Experimental results showed that incorporation of FA improved the mechanical properties, temperature resistance and water stability of MPC composites. TGA results exhibited that the mass loss of MPC composites was gradually reduced by increasing the... 

    Sonophotocatalytic degradation of sulfadiazine by integration of microfibrillated carboxymethyl cellulose with Zn-Cu-Mg mixed metal hydroxide/g-C3N4 composite

    , Article Separation and Purification Technology ; Volume 245 , 2020 Gholami, P ; Khataee, A ; Vahid, B ; Karimi, A ; Golizadeh, M ; Ritala, M ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    This research aimed to prepare a recoverable sonophotocatalyst, in which microfibrillated carboxymethyl cellulose (MFC) acted as the Zn-Cu-Mg-mixed metal hydroxide/graphitic carbon nitride (MMH/g-C3N4) carrier. The characteristics of bare and composite sonophotocatalysts were analyzed by the XRD, FT-IR, BET, DRS, PL and FE-SEM equipped with the EDX mapping. The performance of prepared composites (MMH/g-C3N4@MFC) with various weight ratios of the MMH/g-C3N4 was studied for the sonophotocatalytic degradation of sulfadiazine (SDZ) as the model emerging contaminant. 93% of SDZ was degraded using the most effective catalyst (MMH/g-C3N4@MFC3) with 15% weight ratio of the MMH/g-C3N4 under the... 

    Effects of salinity, ion type, and aging time on the crude oil-brine interfacial properties under gravity condition

    , Article Journal of Petroleum Science and Engineering ; Volume 195 , December , 2020 Khajepour, H ; Akhlaghi Amiri, H. A ; Ayatollahi, S ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    In this study, the impacts of salinity, ion type, and aging process were investigated on coalescence and spreading of crude oil interfaces (including an oil droplet and an oil film) under gravity, through drop rest time measurement techniques, aided by an image analysis system. Three different salt solutions of NaCl, Na2SO4, and MgCl2 were studied at different ionic strengths, ranged from 1% to 150% of Persian Gulf seawater ionic strength. According to the results, aging the oil droplet in the brine increased the interfacial rigidity. Addition of a gas phase - by thinning the surface oil film - almost doubled both rest time and spreading time values. In the aged mode, the presence of salt in... 

    Atomistic insight into the behavior of ions at an oil-bearing hydrated calcite surface: implication to ion-engineered waterflooding

    , Article Energy and Fuels ; Volume 35, Issue 16 , 2021 , Pages 13039-13054 ; 08870624 (ISSN) Badizad, M. H ; Koleini, M. M ; Greenwell, H. C ; Ayatollahi, S ; Ghazanfari, M. H ; Sharif University of Technology
    American Chemical Society  2021
    Abstract
    This research provides an atomistic picture of the role of ions in modulating the microstructural features of an oil-contaminated calcite surface. This is of crucial importance for the rational design of ion-engineered waterflooding, a promising technique for enhancing oil recovery from carbonate reservoirs. Inspired by a conventional lab-scale procedure, an integrated series of molecular dynamics (MD) simulations were carried out to resolve the relative contribution of the major ionic constituent of natural brines (i.e., Na+, Cl-, Mg2+, Ca2+, and SO42-) when soaking an oil-bearing calcite surface in different electrolyte solutions of same salinity, namely, CaCl2, MgCl2, Na2SO4, MgSO4, and... 

    Fabrication and microwave dielectric characterization of cordierite/BZBS (Bi2O3-ZnO-B2O3-SiO2) glass composites for LTCC applications

    , Article Journal of Alloys and Compounds ; Volume 882 , 2021 ; 09258388 (ISSN) Ebrahimi, F ; Nemati, A ; Banijamali, S ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    The present work aims to fabricate cordierite/BZBS glass (Bi2O3-ZnO-B2O3-SiO2) composites through one-step heat treatment. Cordierite was synthesized from a solid-state reaction of aluminum hydroxide, magnesium hydroxide, and silica gel. BZBS glass was obtained through the classic melt quenching technique. Milled cordierite powder was mixed with different volume fractions of glass powders and heat treated at 950 °C. Considering the densification behavior along with the microwave dielectric features, two composites (C70G30 and C60G40) were chosen for further examination. These composites were separately heat treated at different temperatures from 650 up to 900 °C, then characterized due to... 

    Novel experimental evidence on the impact of surface carboxylic acid site density on the role of individual ions in the electrical behavior of crude oil/water

    , Article Journal of Molecular Liquids ; Volume 362 , 2022 ; 01677322 (ISSN) Farhadi, H ; Mahmoodpour, S ; Ayatollahi, S ; Fatemi, M ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Perceiving the electrical behavior of the rock/brine and the crude oil/brine interfaces gives insight into the performance of engineered waterflooding. Compared to the rock surface, few studies have attempted to comprehend the complex behavior of the crude-oil surface electrical behavior. To reveal the impact of each ion on the surface charge of crude oil, the zeta potential of crude oil/single-salt brines (including NaCl, CaCl2, MgCl2, Na2SO4, and NaHCO3) was measured in a wide range of salinity. Then, the counterpart interfacial tension (IFT) was measured to determine the capability of each brine in bringing carboxylic acid groups from crude-oil bulk (COOH) to crude oil/brine interface... 

    Spinel MgAl2O4 nanospheres coupled with modified graphitic carbon nitride nanosheets as an efficient Z-scheme photocatalyst for photodegradation of organic contaminants

    , Article Applied Surface Science ; Volume 585 , 2022 ; 01694332 (ISSN) Zehtab Salmasi, M ; Kazemeini, M ; Sadjadi, S ; Nematollahi, R ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    In this contribution, spinel MgAl2O4 nanospheres prepared by the combustion method were coupled with thermally-exfoliated g-C3N4 nanosheets (TE-GCN) through an efficient isoelectric point-assisted calcination technique. Physical characteristics of the synthesized nanocomposite were understudied utilizing the XRD, FT-IR, FE-SEM, TEM, BET-BJH, UV–Vis DRS, PL, and EIS analyses. This material was used as a novel nano-photocatalyst for degradation of reactive red 195 (RR195) industrial dye contaminant. Results revealed that, a successful synthesis of a heterojunction between the components of the nanocomposite was achieved. This exhibited an enormously improved electron-hole separation leading to... 

    A two step Microwave-assisted coke resistant mesoporous Ni-Co catalyst for methane steam reforming

    , Article Fuel ; Volume 317 , 2022 ; 00162361 (ISSN) Etminan, A ; Sadrnezhaad, S. K ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    Methane steam reforming (MSR) is an assuring reaction using steam to produce H2 as clean energy over a nicκel-based catalyst. We synthesized mesoporous monometallic NiMgAl2O4 and bimetallic NiCoMgAl2O4 catalysts in a two-step combustion method using a mix of fuels and powder metallurgy. BET-BJH, XRD, TGA, TPR, FESEM, and EDX-mapping characterized surface area, porosity, morphology, crystalline structure, and metal-support interaction behavior. The products exhibited strong interaction of well-structured MgAl2O4 spinel with NiO, in both specimens. The MSR evaluation tests at 750 °C under atmospheric pressure, CH4:H2O feed ratio of 1:1.2 showed the bimetallic catalyst has the highest...