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    Effective promotion of g–C3N4 photocatalytic performance via surface oxygen vacancy and coupling with bismuth-based semiconductors towards antibiotics degradation

    , Article Chemosphere ; Volume 287 , 2022 ; 00456535 (ISSN) Hasanvandian, F ; Moradi, M ; Aghaebrahimi Samani, S ; Kakavandi, B ; Rahman Setayesh, S ; Noorisepehr, M ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    In this research, the potential of bismuth chromate (BCO), a new bismuth-based semiconductor belongs to the family of Bi2XO6 (X = Mo, W, or Cr), was introduced by a novel 1D/2D structure consist of BCO nanobelts and N2-freezed ultra-wrinkled graphitic carbon nitride (N–CN) nanosheets. To enhance intimate contact between BCO and N–CN (BCO/N–CN composite), surface oxygen vacancy (VO) was created as an efficient electron transfer highway using a simple alkaline-treatment-assisted method. Various characterization techniques, including XRD, FT-IR, EPR, FE-SEM, TEM, BET, DRS, PL, EIS, and photocurrent transient analyses were conducted to elucidate the physicochemical aspects of catalysts. The... 

    An optimized thermal cracking approach for onsite upgrading of bitumen

    , Article Fuel ; Volume 307 , 2022 ; 00162361 (ISSN) Salehzadeh, M ; Kaminski, T ; Husein, M. M ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    Onsite partial upgrading is a promising strategy for facilitating pipeline transportation of bitumen without the use of diluent. In the present work, a one-step treatment using an autoclave is optimized toward upgrading Alberta bitumen of 9.6 API gravity and 925,000 cP viscosity. The thermal cracking process was kept simple in order to maintain an economic and environmental advantage. Optimum conditions entailed 75 min of reaction time at 420 °C, without quenching the reactor. These conditions corresponded to highest centrifuged oil product yield of 73.3 ± 1.1 wt%, viscosity of 34 ± 2 cP and API gravity of 18.9 ± 0.5. H-NMR, CHNS and FTIR measurements revealed thermally cracked asphaltenes... 

    A comprehensive study on the complete charging-discharging cycle of a phase change material using intermediate boiling fluid to control energy flow

    , Article Journal of Energy Storage ; Volume 35 , 2021 ; 2352152X (ISSN) Hosseininaveh, H ; Mohammadi, O ; Faghiri, S ; Shafii, M. B ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    The low melting and solidification rates of phase change materials (PCM), which traces back to their low thermal conductivity coefficient, has led the application of these materials to face limitations. This paper aims to explore the effectiveness of a novel method called intermediate boiling fluid (IBF) in speeding up the energy storage and transfer processes in PCMs during a complete charging-discharging cycle. Throughout this novel technique, paraffin and acetone are utilized as PCM and IBF, respectively. In the solidification process, there is no direct contact between the cold source and the molten paraffin, while acetone, as an intermediate fluid, is being boiled via absorbing... 

    Numerical analysis of two-phase flow in heterogeneous porous media during pre-flush stage of matrix acidizing: Optimization by response surface methodology

    , Article Physics of Fluids ; Volume 33, Issue 5 , 2021 ; 10706631 (ISSN) Sabooniha, E ; Rokhforouz, M. R ; Kazemi, A ; Ayatollahi, S ; Sharif University of Technology
    American Institute of Physics Inc  2021
    Abstract
    Oil trapping behavior during the pre-flush stage is critically important to evaluate the effectiveness of matrix acidizing for the oil well stimulation. In this study, the visco-capillary behavior of the two-phase flow in the pore-scale is analyzed to investigate the influence of wetting properties for a natural rock sample. A two-dimensional model, based on Cahn-Hilliard phase-field and Navier-Stokes equations, was established and solved using the finite element method. A stability phase diagram for log capillary number (Ca)-log viscosity ratio (M) was constructed and then compared with the reported experimental works. The maximum and minimum ranges of capillary number and viscosity ratio... 

    Fabrication of a sensitive colorimetric nanosensor for determination of cysteine in human serum and urine samples based on magnetic-sulfur, nitrogen graphene quantum dots as a selective platform and Au nanoparticles

    , Article Talanta ; Volume 226 , 2021 ; 00399140 (ISSN) Afsharipour, R ; Dadfarnia, S ; Haji Shabani, A. M ; Kazemi, E ; Pedrini, A ; Verucchi, R ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    A novel colorimetric nanosensor is reported for the selective and sensitive determination of cysteine using magnetic-sulfur, nitrogen graphene quantum dots (Fe3O4/S, N-GQDs), and gold nanoparticles (Au NPs). Thus, S, N-GQDs was firstly immobilized on Fe3O4 nanoparticles through its magnetization in the presence of Fe3+ in the alkali solution. The prepared Fe3O4/S, N-GQDs were dispersed in cysteine solution resulting in its quick adsorption on the surface of the Fe3O4/S, N-GQDs through hydrogen bonding interaction. Then, Au NPs solution was added to this mixture that after a short time, the color of Au NPs changed from red to blue, the intensity of surface plasmon resonance peak of Au NPs at... 

    Fabrication of a sensitive colorimetric nanosensor for determination of cysteine in human serum and urine samples based on magnetic-sulfur, nitrogen graphene quantum dots as a selective platform and Au nanoparticles

    , Article Talanta ; Volume 226 , 2021 ; 00399140 (ISSN) Afsharipour, R ; Dadfarnia, S ; Haji Shabani, A. M ; Kazemi, E ; Pedrini, A ; Verucchi, R ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    A novel colorimetric nanosensor is reported for the selective and sensitive determination of cysteine using magnetic-sulfur, nitrogen graphene quantum dots (Fe3O4/S, N-GQDs), and gold nanoparticles (Au NPs). Thus, S, N-GQDs was firstly immobilized on Fe3O4 nanoparticles through its magnetization in the presence of Fe3+ in the alkali solution. The prepared Fe3O4/S, N-GQDs were dispersed in cysteine solution resulting in its quick adsorption on the surface of the Fe3O4/S, N-GQDs through hydrogen bonding interaction. Then, Au NPs solution was added to this mixture that after a short time, the color of Au NPs changed from red to blue, the intensity of surface plasmon resonance peak of Au NPs at... 

    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... 

    The oxidative desulfurization process performed upon a model fuel utilizing modified molybdenum based nanocatalysts: Experimental and density functional theory investigations under optimally prepared and operated conditions

    , Article Applied Surface Science ; Volume 527 , 2020 Hasannia, S ; Kazemeini, M ; Rashidi, A ; Seif, A ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    CoMo/reduced graphene oxide (rGO) catalyst was synthesized for the oxidative desulfurization process (ODS) of dibenzothiophene (DBT) in n-decane. Parameters including total metal (Co and Mo) loading, Co/Mo and CA (citric Acid)/Mo molar ratios were investigated toward achieving optimum conditions. The catalysts were characterized by the XRD, ICP, FTIR, Raman Spectroscopy, BET-BJH, NH3-TPD, XPS, and TEM methods. The product sulfur content was measured by the ICP-OES while the product was evaluated using FTIR and 1H NMR analyses. All experimental stages were designed using Design-Expert software. High BET area, acidity, uniform particle size, and Co-promoter played key roles in this... 

    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 , March , 2021 Helmi, M ; Tahvildari, K ; Hemmati, A ; Aberoomand azar, P ; Safekordi, A ; Sharif University of Technology
    Elsevier Ltd  2020
    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... 

    Deep eutectic solvents: Cutting-edge applications in cross-coupling reactions

    , Article Green Chemistry ; Volume 22, Issue 12 , 2020 , Pages 3668-3692 Hooshmand, S. E ; Afshari, R ; Ramón, D. J ; Varma, R. S ; Sharif University of Technology
    Royal Society of Chemistry  2020
    Abstract
    Deep eutectic solvents (DESs), surmised as "the organic reaction medium of the century", have reverberated a new symphony throughout the present green millennium. A brief historical account of the DES systems and their physicochemical properties as task-specific and designer solvents for cross-coupling reactions are appraised including the hole theory that explains the underlying mechanistic pathway for this emerging neoteric medium. The insights into cross-coupling reactions and their applications are included, highlighting the significant achievements pertaining to the dual role of DESs as a solvent and catalyst. In addition, popular "name-reactions"for the carbon-carbon and... 

    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... 

    Magnetite nanoparticle as a support for stabilization of chondroitinase ABCI

    , Article Artificial Cells, Nanomedicine and Biotechnology ; Volume 47, Issue 1 , 2019 , Pages 2721-2728 ; 21691401 (ISSN) Askaripour, H ; Vossoughi, M ; Khajeh, K ; Alemzadeh, I ; Sharif University of Technology
    Taylor and Francis Ltd  2019
    Abstract
    Chondroitinase ABCI (cABCI) is a drug enzyme that can be used to treat spinal cord injuries. Due to low thermal stability of cABCI, this enzyme was immobilized on Fe3O4 nanoparticle to increase its thermal stability. The size and morphology, structure and magnetic property of the Fe3O4 nanoparticles were characterized by the analyses of SEM, XRD and VSM, respectively, and FTIR spectroscopy was employed to confirm the immobilization of cABCI on the surface of Fe3O4 nanoparticles. The results indicated that the optimum conditions for pH, temperature, cABCI-to-Fe3O4 mass ratio and incubation time in immobilization process were 6.5, 15 °C, 0.75 and 4.5 h, respectively, and about 0.037 mg cABCI... 

    A novel niosome formulation for encapsulation of anthocyanins and modelling intestinal transport

    , Article Food Chemistry ; Volume 293 , 2019 , Pages 57-65 ; 03088146 (ISSN) Fidan Yardimci, M ; Akay, S ; Sharifi, F ; Sevimli Gur, C ; Ongen, G ; Yesil Celiktas, O ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    The bioavailability of drugs can be improved by regulating the structural properties, particularly lipoid systems, such as niosomes, can increase cellular uptake. Herein, we optimized double emulsion and niosomal formulations for encapsulating anthocyanin-rich black carrot extract. Nanoparticles obtained by selected formulation were characterized in terms of morphology, particle size, drug encapsulation efficiency, in vitro release and cytotoxicity. The optimum conditions for niosomal formulation were elicited as 30 mg of cholesterol, 150 mg of Tween 20 and feeding time of 1 min at a stirring rate of 900 rpm yielding the lowest average particle size of 130 nm. In vitro release data showed... 

    Synthesis of composite coating containing tio2 and ha nanoparticles on titanium substrate by ac plasma electrolytic oxidation

    , Article Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science ; Volume 50, Issue 7 , 2019 , Pages 3310-3319 ; 10735623 (ISSN) Soleymani Naeini, M ; Ghorbani, M ; Chambari, E ; Sharif University of Technology
    Springer Boston  2019
    Abstract
    In this study, biocompatible ceramic layers containing TiO2 and hydroxyapatite (HA) nanoparticles (TiO2/HA) were deposited on pure commercial titanium (Grade 2) by using plasma electrolytic oxidation and AC power supply. The coating process was carried out in five different solutions for various times at a current density of 500 mA cm−2. To achieve the optimum conditions for thickness and microstructure, the coating process was conducted in solutions with a 3 g L−1 concentration of HA nanoparticles. FESEM, XRD, and FTIR results showed that HA nanoparticles were successfully incorporated into the pores of the layer. Furthermore, the corrosion behavior of the coating layers in the simulated... 

    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... 

    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.... 

    Copper recovery from reverberatory furnace flue dust

    , Article International Journal of Mineral Processing ; Volume 157 , 2016 , Pages 205-209 ; 03017516 (ISSN) Mohagheghi, M ; Askari, M ; Sharif University of Technology
    Elsevier, B. V  2016
    Abstract
    In this study, leaching of reverberatory furnace dust at Sarcheshmeh was investigated in H2SO4-O3 medium. Response surface methodology based on central composite face-centered design (RSM-CCF) was applied to optimize the operating parameters. The optimal conditions to achieve the principle objectives of maximizing copper dissolution and minimizing iron dissolution from dust were identified to be a temperature of 30 °C, a leaching time of 3 h, an initial pH of 0.5, a pulp density of 20%, and an ozone flow rate of 1 g/h. Under the optimum conditions, the copper and iron concentrations in the leaching solution were found to be 27.11 and 0.90 g/L, respectively. The results showed that selective... 

    Colorimetric detection of glutathione based on transverse overgrowth of high aspect ratio gold nanorods investigated by MCR-ALS

    , Article RSC Advances ; Volume 5, Issue 101 , 2015 , Pages 82906-82915 ; 20462069 (ISSN) Fahimi Kashani, N ; Shadabipour, P ; Hormozi-Nezhad, M. R ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    In this paper, we present a simple platform for colorimetric detection of glutathione using gold nanorods (AR ∼ 6.5 ± 0.2) as a plasmonic sensor. The functional mechanism of the sensor is based on shifts of longitudinal plasmon resonance during selective transverse overgrowth induced by preferential binding of glutathione at the nanorod tips. Under the optimum conditions, a calibration curve showed two linear regimes at the range of 50 nM to 20 μM of glutathione with a detection limit as low as 40 nM. The nanosensor maintains relatively high selectivity for determination of glutathione in the presence of several other amino acids. However, cysteine at similar concentration levels strongly... 

    Enhancement of fungal delignification of rice straw by Trichoderma viride sp. to improve its saccharification

    , Article Biochemical Engineering Journal ; Volume 101 , September , 2015 , Pages 77-84 ; 1369703X (ISSN) Ghorbani, F ; Karimi, M ; Biria, D ; Kariminia, H. R ; Jeihanipour, A ; Sharif University of Technology
    Elsevier  2015
    Abstract
    Fungal delignification can be considered as a feasible process to pre-treat lignocellulosic biomass in biofuel production, if its performance is improved in terms of efficiency thorough a few modifications. In this study, Trichoderma viride was utilized to investigate the effect of wet-milling, addition of surfactant (Tween 80) and optimization of operating factors such as temperature, biomass to liquid medium ratio and glucose concentration on biodelignification of rice straw. Next, the enzymatic hydrolysis of pretreated biomass was studied at various pretreatment times. Results revealed that the wet milling and addition of surfactant increases the lignin removal about 15% and 11%,... 

    Refined microstructure of compo cast nanocomposites: the performance of combined neuro-computing, fuzzy logic and particle swarm techniques

    , Article Neural Computing and Applications ; Volume 26, Issue 4 , May , 2015 , Pages 899-909 ; 09410643 (ISSN) Ostad Shabani, M ; Rahimipour, M. R ; Tofigh, A. A ; Davami, P ; Sharif University of Technology
    Springer-Verlag London Ltd  2015
    Abstract
    Aluminum metal matrix composites (MMCs) reinforced with nanoceramics are ideal materials for the manufacture of lightweight automotive and other commercial parts. Adaptive neuro-fuzzy inference system combined with particle swarm optimization method is implemented in this research study in order to optimize the parameters in processing of aluminum MMCs. In order to solve the problems associated with poor wettability, agglomeration and gravity segregation of nanoparticles in the melt, a mixture of alumina and aluminum particles was used as the reinforcement instead of raw nanoalumina. Microstructural characterization shows dendritic microstructure for the sand cast and non-dendritic...