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    Graphene oxide in generation of nanobubbles using controllable microvortices of jet flows

    , Article Carbon ; Volume 138 , 2018 , Pages 8-17 ; 00086223 (ISSN) Jannesari, M ; Akhavan, O ; Madaah Hosseini, H. R ; Sharif University of Technology
    Elsevier Ltd  2018
    Spontaneous generation of nanobubbles (NBs) was developed by using a controllable platform of superfast microvortices, based on turbulent jet flows in the presence of graphene oxide (GO) sheets. Very high energy dissipation rates through discharging warm water into cold N2 aqueous solutions resulted in creation of micro/submicro-vortices. Shear stresses in these domains generated gas local supersaturations, leading to the formation of high concentration (∼109 mL−1) of stable NBs. Introducing GO sheets into the microvortex system resulted in effective manipulation of NBs by providing energetically favorable sites for prompt heterogeneous nucleation as well as stronger shear rate fluctuations.... 

    Crystallization kinetics of glass-ceramics by differential thermal analysis

    , Article Ceramics - Silikaty ; Volume 55, Issue 2 , May , 2011 , Pages 188-194 ; 08625468 (ISSN) Ghasemzadeh, M ; Nemat, A ; Nozad, A ; Hamnabard, Z ; Baghshah, S ; Sharif University of Technology
    The crystallization behavior of fluorphlogopite, a glass-ceramic in the MgO-SiO2-Al2O3-K2O-B 2O3-F system, was studied by substitution of Li 2O for K2O in the glass composition. DTA, XRD and SEM were used for the study of crystallization behavior, formed phases and microstructure of the resulting glass-ceramics. Crystallization kinetics of the glass was investigated under non-isothermal conditions, using the formal theory of transformations for heterogeneous nucleation. The crystallization results were analyzed, and both the activation energy of crystallization process as well as the crystallization mechanism were characterized. Calculated kinetic parameters indicated that the appropriate... 

    Biomimetic apatite layer formation on a novel citrate starch scaffold suitable for bone tissue engineering applications

    , Article Starch/Staerke ; Volume 68, Issue 11-12 , 2016 , Pages 1275-1281 ; 00389056 (ISSN) Nourmohammadi, J ; Shahriarpanah, S ; Asadzadehzanjani, N ; Khaleghpanah, S ; Heidari, S ; Sharif University of Technology
    Wiley-VCH Verlag  2016
    The formation of biomimetic bone-like apatite layers throughout the biopolymer-based hydrogel scaffold is an attractive approach in bone tissue engineering. Here, the starch scaffold was prepared using a combination of particulate leaching and freeze-drying techniques. The fabricated structures were then modified by citric acid to investigate the formation of bone-like apatite layer on the porous citrate-based scaffold after soaking in simulated body fluid (SBF). The Fourier Transform Infrared (FTIR) spectra and X-ray diffraction (XRD) patterns revealed that the B-type carbonated apatite has successfully deposited on the scaffold after immersing in SBF for 28 days. Indeed, high chemical... 

    On the controllability of phase formation in rapid solidification of high entropy alloys

    , Article Journal of Alloys and Compounds ; Volume 748 , 2018 , Pages 679-686 ; 09258388 (ISSN) Jafary Zadeh, M ; Aitken, Z. H ; Tavakoli, R ; Zhang, Y. W ; Sharif University of Technology
    Elsevier Ltd  2018
    The demonstration of high entropy alloys (HEAs), or more generally multi-principal-element alloys (MPEAs), which display a greater resistance to softening at elevated temperatures and embrittlement at cryogenic temperatures, has offered an accessible alternative alloying process for materials scientists and engineers. Although solidification is a fundamental process in synthesis of alloys which strongly affects their microstructure and properties, a firm understanding of this process in HEAs is scarce. Here, using molecular dynamics (MD) simulations, we study the rapid solidification of the multi-principal-element CoFeNiPd alloy as a prototypical single-phase HEA. Our simulations reveal an...