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    Promising new catalytic properties of a Co (II)-carboxamide complex and its derived Co3O4 nanoparticles for the Mizoroki-Heck and the Epoxidation reactions

    , Article Applied Organometallic Chemistry ; Volume 34, Issue 11 , November , 2020 Kiani, M ; Bagherzadeh, M ; Meghdadi, S ; Fadaei Tirani, F ; Babaie, M ; Schenk Joß, K ; Sharif University of Technology
    John Wiley and Sons Ltd  2020
    Abstract
    The new Co(II) - carboxamide complex (1) and Co3O4 nanoparticles (2), by way of thermal decomposition of (1) have been efficiently synthesised in the environment-friendly. X-ray diffraction reveals a slightly distorted octahedral coordination of cobalt (four nitrogens and two oxygens) in (1) and regular octahedral or tetrahedral ones (oxygens only) in (2). The investigation of (1) and (2) in the Mizoroki-Heck and epoxidation of alkens reactions showed them both to be powerful, green and inexpensive catalysts. © 2020 John Wiley & Sons, Ltd  

    Pulsed laser irradiation for environment friendly reduction of graphene oxide suspensions

    , Article Applied Surface Science ; Vol. 301 , May , 2014 , pp. 183-188 ; ISSN: 01694332 Ghadim, E. E ; Rashidi, N ; Kimiagar, S ; Akhavan, O ; Manouchehri, F ; Ghaderi, E ; Sharif University of Technology
    Abstract
    Graphene oxide (GO) sheets were synthesized through a modified Hummers' method. Using high resolution transmission electron microscopy the thickness of the GO sheets in a multilayer structure of stacked GO sheets was found ∼0.8 nm. A nanosecond pulsed laser (with wavelength of 532 nm and average power of 0.3 W) was applied for effective and environment friendly reduction of the GO sheets in an ammonia solution (pH ∼9) at room temperature conditions. The deoxygenation of the GO sheets by the pulsed laser reduction method was confirmed by using UV-visible, Fourier transform infrared, X-ray photoelectron spectroscopy (XPS) and thermo gravimetric analysis. Based on XPS analysis, the O/C ratio of... 

    Hydrogen-rich water for green reduction of graphene oxide suspensions

    , Article International Journal of Hydrogen Energy ; Volume 40, Issue 16 , 2015 , Pages 5553-5560 ; 03603199 (ISSN) Akhavan, O ; Azimirad, R ; Gholizadeh, H. T ; Ghorbani, F ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    Abstract H2-rich water as a green antioxidant was applied for deoxygenation of graphene oxide (GO) suspensions. The ability of H2-rich water for deoxygenation of GO sheets was found comparable to the ability of hydrazine (as a standard and powerful reductant), using X-ray photoelectron spectroscopy. In fact, the O/C ratio of GO sheets could be reduced from 0.51 to 0.21 and 0.16 by H2-rich water and hydrazine, respectively. More importantly, while C-N bond formation is one of the side effects of GO reduction by hydrazine, no chemical C-N bond was found on the H2-water-reduced GO (rGO) sheets. This also resulted in a better restoration of the graphitic structure of the H2-water-rGO, as... 

    Influence of heavy nanocrystals on spermatozoa and fertility of mammals

    , Article Materials Science and Engineering C ; Volume 69 , 2016 , Pages 52-59 ; 09284931 (ISSN) Akhavan, O ; Hashemi, E ; Zare, H ; Shamsara, M ; Taghavinia, N ; Heidari, F ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    In recent years, quantum dots (QDs) have been widely used in upcoming nanotechnology-based solar cells, light-emitting diodes and even bioimaging, due to their tunable optical properties and excellent quantum yields. But, such nanostructures are currently constituted by heavy elements which can threat the human health and living environment. Hence, in this work, the in vivo effects of CdTe nanocrystals (NCs) (as one of the promising QDs) on spermatozoa of male mice and subsequently on fertility of female mice were investigated, for the first time. To do this, CdTe NCs were synthesized through an environment-friendly (aqueous-based solution) method. The sperm cells presented a high potential... 

    Reliability analysis of rammed earth structures

    , Article Construction and Building Materials ; Volume 127 , 2016 , Pages 884-895 ; 09500618 (ISSN) Kianfar, E ; Toufigh, V ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    Rammed earth (RE) structures are widely used for more sustainable and environment-friendly buildings. Due to lack of design standards, the engineering decisions often rely on rule-of-thumb method which may lead to quite conservative or unsafe designs. In this study, load and resistance parameters were treated as random variables in reliability analysis. The reliability index and failure probability of RE structures were evaluated using First-Order-Reliability-Method (FORM) and then compared with Second-Order-Reliability-Method (SORM) and Monte Carlo Sampling method. The analysis was performed based on the different a) load combinations, b) wall geometry, c) material type (unstabilized or...