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    Removal of naphthalene from aqueous solutions by phosphorus doped-titanium dioxide coated on silica phosphoric acid under visible light

    , Article Desalination and Water Treatment ; Volume 224 , 2021 , Pages 187-196 ; 19443994 (ISSN) Banaei, B ; Hassani, A. H ; Tirgir, F ; Fadaei, A ; Borghaei, S. M ; Sharif University of Technology
    Desalination Publications  2021
    In this research, titanium dioxide-phosphorus (TiO2-P) immobilized on silica phosphoric acid (SPA) was prepared by a simple modified sol–gel method with SPA as a precursor instead of phosphoric acid. TiO2-P thin film photocatalyst immobilized on SPA as a novel high-efficiency photocatalyst was investigated to remove naphthalene as a toxic compound from wastewater. The novel resulting photocatalyst were characterized by energy-dispersive X-ray (EDX) and X-ray diffraction pattern revealed nano-photocatalyst TiO2-P with the average size of 15–20 nm. EDX analysis showed the presence of phosphorus elements in the crystalline structure of TiO2 and diffuse reflectance spectroscopy showed the energy... 

    ZrN fractal-graphene-based metamaterial absorber in the visible and near-IR regimes

    , Article Optik ; Volume 237 , 2021 ; 00304026 (ISSN) Baqir, M. A ; Choudhury, P. K ; Niaz Akhtar, M ; Sharif University of Technology
    Elsevier GmbH  2021
    The absorption characteristics of zirconium nitride (ZrN)-based metamaterial absorber of fractal geometry are studied. The proposed absorber is comprised of fractal metasurface at the top having subwavelength-sized periodic pattern of specially designed ZrN circular nano-discs arranged over silicon dioxide (SiO2) substrate. A tri-layer graphene, owing to its exhibiting better tunability, is introduced at the interface of metasurface and substrate. The bottom side of SiO2 is coated with silver nanolayer to block transmission. The absorptivity essentially depends on the kind of fractal design used in metasurface to configure the absorber. The obtained results exhibit the absorption... 

    Engineering of metallic nanorod-based hyperbolic metamaterials for broadband applications operating in the infrared regime

    , Article Applied Nanoscience (Switzerland) ; Volume 11, Issue 1 , 2021 , Pages 229-240 ; 21905509 (ISSN) Baqir, M. A ; Farmani, A ; Raza, M ; Niaz Akhtar, M ; Hussain, A ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Metamaterials are manmade structures that have attained considerable attention over the past 2 decades in the modern fields like cloaking, sensing, and imaging owing to their ability to harness electromagnetic fields. In this regard, we have inspected the dielectric properties of the hyperbolic metamaterials (HMM) made of metallic nanorods and dielectric medium at the infrared wavelength regime. The periodically arranged subwavelength-sized metallic nanorods embedded in the silicon dioxide (SiO 2) substrate glass. The spacing between two adjacent nanorods is of subwavelength in size. Furthermore, effective permittivity of the metamaterial has been analyzed by employing the Maxwell Garnett... 

    Influence of metal loading and reduction temperature on the performance of mesoporous NiO–MgO–SiO2 catalyst in propane steam reforming

    , Article Journal of the Energy Institute ; Volume 96 , 2021 , Pages 38-51 ; 17439671 (ISSN) Barzegari, F ; Farhadi, F ; Rezaei, M ; Kazemeini, M ; Keshavarz, A ; Sharif University of Technology
    Elsevier B.V  2021
    In this research, a series of NiO–MgO–SiO2 catalyst samples with various nickel contents (5, 10, 15 and 20 wt %) were prepared by a co-precipitation method followed by a hydrothermal treatment and employed in propane steam reforming. The analyses revealed that the enhancement of the nickel content up to 15 wt % improved the propane conversion to 98.6% at 550 °C. Nonetheless, further increase in the nickel loading reduced the catalyst activity due to the formation of larger and more poorly dispersed active sites. Besides, 15 wt % nickel loading led to the high resistance against coke deposition with no detectable carbon on the catalyst surface. In addition, it was revealed that, the decrease... 

    The influence of lanthanide on NiO-MgO-SiO2 catalysts for syngas production via propane steam reforming

    , Article Molecular Catalysis ; Volume 499 , 2021 ; 24688231 (ISSN) Barzegari, F ; Rezaei, M ; Kazemeini, M ; Farhadi, F ; Keshavarz, A ; Sharif University of Technology
    Elsevier B.V  2021
    In this study, 15 wt. % NiO-MgO-SiO2 catalysts modified by La2O3 promoter were prepared through a co-precipitation route and employed for syngas production via propane steam reforming. Various techniques including X-Ray diffraction, BET, TPR, CO2-TPD, CO-chemisorption, TPO, and Scanning electron microscopy were utilized to characterize the final samples. The results indicated that the incorporation of La2O3 enhanced the metal-support interaction providing less reducible Ni species. In comparison with the La-free catalyst, the promoted ones possessed higher metal dispersion and smaller Ni particles. Nonetheless, excessive amounts of La covering the active sites negatively decreased the Ni... 

    Electrospun chitosan/polyvinyl alcohol nanocomposite holding polyaniline/silica hybrid nanostructures: An efficient adsorbent of dye from aqueous solutions

    , Article Journal of Molecular Liquids ; Volume 331 , 2021 ; 01677322 (ISSN) Bayat, A ; Tati, A ; Ahmadipouya, S ; Haddadi, S. A ; Arjmand, M ; Sharif University of Technology
    Elsevier B.V  2021
    In this work, the addition of a novel polyaniline (PANI)/silica (SiO2) nanostructure (PSn) in chitosan/polyvinyl alcohol nanofibers (CP) was evaluated to enhance the dye removal capacity of CP. Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS) results confirmed the chemical grafting of SiO2 on PANI nanoparticles. Brunauer-Emmett-Teller (BET) results showed a specific surface area of 61 m2 g−1 for the PSn filled CP nanofiber (CP-PSn). FE-SEM and EDS-elemental mapping results showed the uniform dispersibility of PSn in CP nanofibers. After the addition of PSn into CP, the adsorption capacity of... 

    Effect of silica nanoparticles on carbon dioxide separation performances of PVA/PEG cross-linked membranes

    , Article Chemical Papers ; Volume 75, Issue 7 , 2021 , Pages 3131-3153 ; 03666352 (ISSN) Rizwan Dilshad, M ; Islam, A ; Haider, B ; Sajid, M ; Ijaz, A ; Khan, R. U ; Khan, W. G ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Novel PVA/PEG cross-linked membranes were prepared with (0–20 wt. %) of silica nanoparticles. The presence of both the polymers and additive was confirmed by FTIR analysis. The thermal properties of the membranes were analyzed by TGA and DSC analysis. The morphological and mechanical properties of the membranes were studied by SEM analysis and tensile testing, respectively. The gas permeation performances of the membranes were examined using state-of-the-art gas permeability cell. It was found that permeability of all the gases increased with the increase of silica loading, whereas ideal selectivity of carbon dioxide with respect to nitrogen and methane increased up to 10 wt. % loading 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
    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... 

    Micro-scale evolution of mechanical properties of glass-ceramic sealant for solid oxide fuel/electrolysis cells

    , Article Ceramics International ; Volume 47, Issue 3 , 2021 , Pages 3884-3891 ; 02728842 (ISSN) Fakouri Hasanabadi, M ; Malzbender, J ; Groß Barsnick, S. M ; Abdoli, H ; Kokabi, A. H ; Faghihi Sani, M. A ; Sharif University of Technology
    Elsevier Ltd  2021
    The structural integrity of the sealant is critical for the reliability of solid oxide cells (SOCs) stacks. In this study, elastic modulus (E), hardness (H) and fracture toughness (KIC) of a rapid crystallizing glass of BaO–CaO–SiO2 system termed “sealant G” are reported as determined using an indentation test method at room temperature. A wide range of indentation loads (1 mN–10 N) was used to investigate the load-dependency of these mechanical properties. Values of 95 ± 12 GPa, 5.8 ± 0.2 GPa and 1.15 ± 0.07 MPa m0.5 were derived for E, H and KIC using the most suitable indentation loads. An application relevant annealing treatment of 500 h at 800 °C does not lead to a significant change of... 

    Influence of surface-modified nanoparticles on the hydrodynamics of rising bubbles

    , Article Chemical Engineering and Technology ; Volume 44, Issue 3 , 2021 , Pages 513-520 ; 09307516 (ISSN) Fayzi, P ; Bastani, D ; Lotfi, M ; Miller, R ; Sharif University of Technology
    Wiley-VCH Verlag  2021
    Local velocities of bubbles rising in four different nanosilica solutions were investigated experimentally. Also, the density, viscosity, and surface tension of fumed nanosilica and modified nanosilica solutions were measured. Heat treatment and chemical functionalization were used to modify the properties of silica nanoparticles. It was found that the addition of nanosilica affected the hydrodynamics of the rising bubble by increasing the drag friction at the interface. However, environmentally responsive nanosilica particles behaved like surfactant molecules, due to the interfacial activity of hydrophilic and hydrophobic chains. Silica nanoparticles coated with both hydrophilic and... 

    Developing a new superhydrophilic and superoleophobic poly(4-(1-vinyl-1H-imidazol-3-ium-3-yl) butane-1-sulfonate): vinyl imidazole@Perfluorooctanoic acid@SiO2 coated stainless steel mesh for highly efficient, stable, and durable oil/water separation

    , Article Journal of Coatings Technology and Research ; Volume 18, Issue 2 , 2021 , Pages 511-521 ; 15470091 (ISSN) Ghadimi, M. R ; Siavash Moakhar, R ; Amirpoor, S ; Azad, M ; Dolati, A ; Sharif University of Technology
    Springer  2021
    The design and development of efficient approaches for water–oil separation have had widespread interest. Most previously introduced techniques and materials used for development of the successful separation of oily wastewater could not answer all the desired demands, such as being efficient and environmentally and economically friendly. Therefore, in seeking a novel method capable of answering these expectations, surfaces with special wettability were introduced. A novel, reusable, and recyclable superhydrophilic and superoleophobic poly(Vsim-Vim)@PFOA@SiO2 nanocomposite-coated stainless steel mesh was synthesized through a facile preparation process. Since the most important factors of... 

    Comprehensive hydrothermal analysis of an inclined mini-channel with fin array: by dual/multi-relaxation-time LBM and experimental process on SiO2-glycol rheological/thermal characteristics

    , Article International Journal of Numerical Methods for Heat and Fluid Flow ; Volume 31, Issue 7 , 2021 , Pages 2405-2429 ; 09615539 (ISSN) Kamali, D ; Hejri, S ; Akbar, N ; Hasani Malekshah, E ; Sharif University of Technology
    Emerald Group Holdings Ltd  2021
    Purpose: The purpose of this study is to present a comprehensive hydrothermal analysis on an inclined mini-channel using numerical and experimental techniques. The fin array acts as heat source within the channel, and a wavy wall located at the top of the channel is heat sink. The side walls are insulated with curved profiles. Also, the channel is inclined with four known inclination angles. To solve the governing equations, the dual-multi-relaxation-time lattice Boltzmann method with D2Q9 and D2Q5 lattice models for flow and temperature fields is used, respectively. Also, the channel is filled with SiO2-glycol nanofluid. Design/methodology/approach: Identifying the behavior of a thermal... 

    Mechanical characteristics of cement paste in the presence of carbon nanotubes and silica oxide nanoparticles: An experimental study

    , Article Materials ; Volume 14, Issue 6 , 2021 ; 19961944 (ISSN) Karakouzian, M ; Farhangi, V ; Farani, M. R ; Joshaghani, A ; Zadehmohamad, M ; Ahmadzadeh, M ; Sharif University of Technology
    MDPI AG  2021
    Considering the remarkable characteristics of nanomaterials, previous research studies investigated the effects of incorporating different types of these materials on improving the concrete properties. However, further studies are required to evaluate the complementary hybridization and synergistic influence of nanomaterials. In this research, the combined effect of adding nano silica particles (NS) and multi-walled carbon nanotubes (MWCNT) on enhancing both the compressive and flexural strengths of the cement paste was investigated. Moreover, the morphology of the interface between cement paste and aggregates was studied by scanning electron microscopy (SEM). The mixtures were prepared... 

    Effect of EPS beads in lightening a typical zeolite and cement-treated sand

    , Article Bulletin of Engineering Geology and the Environment ; Volume 80, Issue 11 , 2021 , Pages 8615-8632 ; 14359529 (ISSN) Khajeh, A ; Ebrahimi, S. A ; MolaAbasi, H ; Jamshidi Chenari, R ; Payan, M ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    The current study aims to assess the influence of EPS beads inclusion on the strength properties of stabilized poorly-graded sands. Various contents of zeolite and cement as stabilizing agents, with the total amounts of 4, 8, and 12% by dry soil weight, and also 0, 0.25, and 0.5% weight ratios of EPS beads (η) are examined. Zeolite is opted among a variety of pozzolanic materials so as to replace a part of cement (0, 10, 30, 50, 70, and 90%) due to its superior environmentally friendly properties. The stress–strain behavior, unconfined compressive strength (UCS), peak strain energy (Eu), and California bearing capacity (CBR) of the zeolite and cement-treated sand-EPS beads mixtures are... 

    Preparation and characterization of self-electrical stimuli conductive gellan based nano scaffold for nerve regeneration containing chopped short spun nanofibers of PVDF/MCM41 and polyaniline/graphene nanoparticles: Physical, mechanical and morphological studies

    , Article International Journal of Biological Macromolecules ; Volume 167 , 2021 , Pages 881-893 ; 01418130 (ISSN) Mohseni, M ; S. A., A. R ; H Shirazi, F ; Nemati, N. H ; Sharif University of Technology
    Elsevier B.V  2021
    Conductive self -electrical stimuli bioactive scaffolds could be used the potential for peripheral nerve regeneration with the maximum efficiency. To produce such conductive self-electrical stimuli bioactive scaffolds, chopped spun piezoelectric nanofibers of polyvinylidene fluoride/mesoporous silica nanoparticle (PVDF/MCM41) are prepared and incorporated in gellan/polyaniline/graphene (gellan/PAG) nanocomposites which have been previously prepared by incorporation of polyaniline/graphene (PAG) nanoparticles in gellan gel at 80 °C. Highly conductive binary doped polyaniline/graphene nanoparticles are prepared by chemical oxidative polymerization of aniline monomer using in-suite... 

    Diatoms with invaluable applications in nanotechnology, biotechnology, and biomedicine: Recent advances

    , Article ACS Biomaterials Science and Engineering ; Volume 7, Issue 7 , 2021 , Pages 3053-3068 ; 23739878 (ISSN) Rabiee, N ; Khatami, M ; Jamalipour Soufi, G ; Fatahi, Y ; Iravani, S ; Varma, R. S ; Sharif University of Technology
    American Chemical Society  2021
    Diatoms are unicellular microalga found in soil and almost every aquatic environment (marine and fresh water). Biogenic silica and diatoms are attractive for biotechnological and industrial applications, especially in the field of biomedicine, industrial/synthetic manufacturing processes, and biomedical/pharmaceutical sciences. Deposition of silica by diatoms allows them to create micro- or nanoscale structures which may be utilized in nanomedicine and especially in drug/gene delivery. Diatoms with their unique architectures, good thermal stability, suitable surface area, simple chemical functionalization/modification procedures, ease of genetic manipulations, optical/photonic... 

    Simulation of wellbore drilling energy saving of nanofluids using an experimental taylor–couette flow system

    , Article Journal of Petroleum Exploration and Production ; Volume 11, Issue 7 , 2021 , Pages 2963-2979 ; 21900558 (ISSN) Rashidi, M ; Sedaghat, A ; Misbah, B ; Sabati, M ; Vaidyan, K ; Mostafaeipour, A ; Hosseini Dehshiri, S. S ; Almutairi, K ; Issakhov, A ; Oloomi, S. A. A ; Malayer, M. A ; Arockia Dhanraj, J ; Sharif University of Technology
    Springer Science and Business Media B.V  2021
    Power consumption of wellbore drilling in oil and gas exploitations count for 40% of total costs, hence power saving of WBM (water-based mud) by adding different concentrations of Al2O3, TiO2 and SiO2 nanoparticles is investigated here. A high-speed Taylor–Couette system (TCS) was devised to operate at speeds 0–1600 RPM to simulate power consumption of wellbore drilling using nanofluids in laminar to turbulent flow conditions. The TCS control unit uses several sensors to record current, voltage and rotational speed and Arduino microprocessors to process outputs including rheological properties and power consumption. Total power consumption of the TCS was correlated with a second-order... 

    Recovery of uranium from carbonaceous radioactive waste of the UF6 production line in a uranium conversion plant: Laboratory and pilot plant studies

    , Article Hydrometallurgy ; Volume 205 , 2021 ; 0304386X (ISSN) Sadeghi, M. H ; Outokesh, M ; Sharifi, M ; Habibi Zare, M ; Sharif University of Technology
    Elsevier B.V  2021
    Carbonaceous radioactive waste is produced by adsorption of effluent gases of UF6 production line, on a bed of charcoal. Current research was aimed at developing a process for recovery of uranium from this waste in a laboratory and at pilot scale. As a first step, leaching of uranium from carbonaceous radioactive waste was undertaken by successive steps using Al(NO3)3 and nitric acid, the former used to eliminate corrosivity of the F− ions. The stoichiometry of reaction between F− and Al3+ ions form complexes ranging from AlF2+, AlF2+ to AlF3 depending upon their molar ratio. The results showed that the increase of NO3−/U ratio increased the uranium leaching efficiency. Presence of some... 

    Alkali-activated slag (AAS) paste: Correlation between durability and microstructural characteristics

    , Article Construction and Building Materials ; Volume 267 , 2021 ; 09500618 (ISSN) Shariati, M ; Shariati, A ; Trung, N. T ; Shoaei, P ; Ameri, F ; Bahrami, N ; Zamanabadi, S. N ; Sharif University of Technology
    Elsevier Ltd  2021
    This study was aimed at evaluating the effects of alkali activator solution and utilization of silica fume (SF) on durability and microstructural characteristics of alkali-activated ground granulated blast furnace slag (GGBFS) pastes. The pastes were activated with sodium silicate (SS) blended with NaOH (SH) solution with molar concentrations of 8 M, 12 M, and 16 M and SS:SH ratios of 1.0, 2.5, and 4.0. The same mixes were prepared with SF as partial replacement of GGBFS at a dosage of 10% by weight. The initial and final water absorption as well as the electrical resistivity of the specimens were measured. The optimal paste fabricated with 12 M NaOH solution and SS:SH ratio of 2.5 showed... 

    Phase-only femtosecond optical pulse shaping based on an all-dielectric polarization-insensitive metasurface

    , Article Optics Express ; Volume 29, Issue 22 , 2021 , Pages 36900-36914 ; 10944087 (ISSN) Abbaszadeh, A ; Tehranian, A ; Salehi, J. A ; Sharif University of Technology
    The Optical Society  2021
    Recently, metasurfaces capable of manipulating the amplitude and the phase of an incident wave in a broad frequency band have been employed for femtosecond optical pulse shaping purposes. In this study, we introduce a phase-only pulse shaper based on an all-dielectric CMOS-compatible polarization-insensitive metasurface, composed of Si nano cylinders sitting on a fused silica substrate. The required phase profile of the metasurface for desired waveforms are calculated using an iterative Fourier transform algorithm, and the performance of the pulse shaper metasurface in implementing the phase masks was assessed using full-wave simulations. Such approach for realizing a...