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    Surface micromorphology and fractal geometry of Co/CP/X (X = Cu, Ti, SM and Ni) nanoflake electrocatalysts

    , Article RSC Advances ; Volume 6, Issue 32 , 2016 , Pages 27228-27234 ; 20462069 (ISSN) Ţəlu, Ş ; Solaymani, S ; Bramowicz, M ; Naseri, N ; Kulesza, S ; Ghaderi, A ; Sharif University of Technology
    Royal Society of Chemistry  2016
    This paper analyses the three-dimensional (3-D) surface texture of Co/CP/X (X = Cu, Ti, SM and Ni, CP: carbonaceous paste) nanoflakes prepared electrochemically using a conventional three electrode system. The surface chemical composition of the samples was investigated by X-ray photoelectron spectroscopy (XPS). Surface images were recorded using scanning electron microscopy (SEM) and analyzed by means of the fractal geometry. Statistical, fractal and functional surface properties of the prepared samples were computed. The statistical functions applied to the SEM data were employed in order to characterise the surfaces topographically (in amplitude, spatial distribution and pattern of... 

    A study of structural, magnetic and various dielectric parameters of Ca-Substituted W-Type hexaferrites for applications at 1–6 GHz frequencies

    , Article Journal of Electronic Materials ; Volume 48, Issue 11 , 2019 , Pages 7149-7161 ; 03615235 (ISSN) ur Rehman, A ; Shaukat, S. F ; Akhtar, M. N ; Ahmad, M ; Sharif University of Technology
    Springer New York LLC  2019
    Single phase Ca-substituted W-type hexaferrites Sr1-xCaxZn2Fe16O27(x = 0.00(0.25)1.00) have successfully been synthesized by using sol–gel self-combustion at 1300°C. These hexaferrites are investigated by x-ray difrractometry (XRD), scanning electron microscopy, energy dispersive x-ray spectroscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometry, and vector network analysis. XRD analysis confirms the formation of a single W-type hexaferrites phase. The DC electrical resistivity increases with incrementing Ca contents. The morphology of all the hexaferrites shows hexagonal platelet-like structure. The prepared ferrites depict soft magnetic nature with high saturation... 

    Site-specific protein conjugation onto fluorescent single-walled carbon nanotubes

    , Article Chemistry of Materials ; Volume 32, Issue 20 , 2020 , Pages 8798-8807 Zubkovs, V ; Wu, S. J ; Rahnamaee, S. Y ; Schuergers, N ; Boghossian, A. A ; Sharif University of Technology
    American Chemical Society  2020
    Semiconducting single-walled carbon nanotubes (SWCNTs) are among the few photostable optical emitters that are ideal for sensing, imaging, drug delivery, and monitoring of protein activity. These applications often require strategies for immobilizing proteins onto the nanotube while preserving the optical properties of the SWCNTs. Site-specific and oriented immobilization strategies, in particular, offer advantages for improving sensor and optical signaling responses. In this study, we demonstrate site-specific protein immobilization of a model of enhanced yellow fluorescent protein with a single engineered cysteine residue, using either single-stranded DNA or a pyrene-containing linker to... 

    Seasonal and interannual cycles of total phytoplankton phenology metrics in the Persian Gulf using ocean color remote sensing

    , Article Continental Shelf Research ; Volume 237 , 2022 ; 02784343 (ISSN) Zoljoodi, M ; Moradi, M ; Moradi, N ; Sharif University of Technology
    Elsevier Ltd  2022
    Spatial and temporal patterns of climatological seasonality, interannual variability, and phytoplankton phenology were estimated using satellite-derived ocean color chlorophyll-a data (Chl-a) 1998 to 2020 in the Persian Gulf from. Biogeography of phytoplankton seasonal and interannual climatology was determined using k-means multivariate clustering analysis applied on the Chl-a time-series data. As a result, two distinct regions were identified: one in the deep north and middle area (DZC) with a minimum value of Chl-a in April–July (0.62–0.76 mg m−3) and maximum in December–February (1.07–1.59 mg m−3), and the other in the north–west coastal areas and along the southwest-southern area (SZC)... 

    The first report on the catalytic oxidation of urazoles to their corresponding triazolinediones via in situ catalytic generation of Br+ using periodic acid or oxone®/KBr system

    , Article Journal of Molecular Catalysis A: Chemical ; Volume 270, Issue 1-2 , 2007 , Pages 219-224 ; 13811169 (ISSN) Zolfigol, M. A ; Bagherzadeh, M ; Mallakpour, S ; Chehardoli, G ; Ghorbani Choghamarani, A ; Koukabi, N ; Dehghanian, M ; Doroudgar, M ; Sharif University of Technology
    A combination of periodic acid or oxone® and a catalytic amount of KBr in the presence of few drops of water, were used for the catalytic oxidation of urazoles and bis-urazoles to their corresponding triazolinediones under mild and heterogeneous conditions with moderate to excellent yields. © 2007 Elsevier B.V. All rights reserved  

    Mild and heterogeneous oxidation of urazoles to their corresponding triazolinediones via in situ generation Cl+ using silica sulfuric acid/KClO3 or silica chloride/oxone system

    , Article Catalysis Communications ; Volume 8, Issue 3 , 2007 , Pages 256-260 ; 15667367 (ISSN) Zolfigol, M. A ; Bagherzadeh, M ; Mallakpour, S ; Chehardoli, G ; Kolvari, E ; Ghorbani Choghamarani, A ; Koukabi, N ; Sharif University of Technology
    A combination of silica sulfuric acid and potassium chlorate or oxone® and silica chloride in the presence of wet SiO2 was used as an effective oxidizing agent for the oxidation of urazoles and bis-urazoles to their corresponding triazolinediones under mild and heterogeneous conditions with moderate to excellent yields. © 2006 Elsevier B.V. All rights reserved  

    Tribromoisocyanuric acid (TBCA) and oxone®-MX systems as oxidizing agents: Oxidative coupling of thiols to their corresponding disulfides under mild and heterogeneous conditions

    , Article Journal of the Chinese Chemical Society ; Volume 54, Issue 5 , 2007 , Pages 1115-1118 ; 00094536 (ISSN) Zolfigol, M. A ; Niknam, K ; Bagherzadeh, M ; Ghorbani Choghamarani, A ; Koukabi, N ; Hajjamia, M ; Kolvaria, E ; Sharif University of Technology
    Chinese Chemical Society Taiwan  2007
    Tribromoisocyanuric acid (TBCA) and Oxone®-MX systems were used as effective oxidizing agents for the oxidation of thiols to their corresponding disulfides under mild conditions at room temperature with good to excellent yields  

    Local calibration of the Hirsch model to determine the degree of blending between aged and virgin asphalt binders

    , Article Road Materials and Pavement Design ; Volume 23, Issue 9 , 2022 , Pages 2132-2150 ; 14680629 (ISSN) Zokaei Ashtiani, M ; Mogawer, W. S ; Tabatabaee, N ; Sharif University of Technology
    Taylor and Francis Ltd  2022
    Aged asphalt binder in reclaimed asphalt pavement (RAP) or recycled asphalt shingles (RAS) blends only partially with the virgin binder. To better understand this state of blending, the asphalt mixtures in this study were designed, mixed, and compacted using different RAP and RAS contents. The asphalt binders were extracted and recovered from RAP and RAS and then blended with different proportions of a virgin binder. The master curves for the asphalt mixtures and asphalt binder blends were then constructed from the measured data. A locally calibrated Hirsch model was developed to estimate master curves for the asphalt mixtures from the corresponding binder-blend data. Pairwise comparison of... 

    Chemoselective and convenient preparation of 1,1-diacetates from aldehydes, mediated by solid lithium perchlorate under solvent-free conditions

    , Article Journal of Molecular Catalysis A: Chemical ; Volume 238, Issue 1-2 , 2005 , Pages 138-141 ; 13811169 (ISSN) Ziyaei, A ; Azizi, N ; Saidi, M. R ; Sharif University of Technology
    A simple, efficient, and general method has been developed for the conversion of aldehydes to 1,1-diacetates with the use of acetic anhydride and solid LiClO4 under first solvent-free and mild conditions in good yields. This method applies to not only simple but also to conjugated aldehydes. © 2005 Elsevier B.V. All rights reserved  

    Dithiocarbamate as an efficient intermediate for the synthesis of 2-(alkylthio)thiazol-4(5H)-ones

    , Article Journal of Sulfur Chemistry ; Volume 37, Issue 5 , 2016 , Pages 529-536 ; 17415993 (ISSN) Ziyaei Halimehjani, A ; Alaei, M. A ; Soleymani Movahed, F ; Jomeh, N ; Saidi, M. R ; Sharif University of Technology
    Taylor and Francis Ltd  2016
    An effective approach for the synthesis of 2-(alkylthio)thiazol-4(5H)-ones from alkyl dithiocarbamates and chloroacetyl chloride in the presence of NaHCO3 has been developed. Good to excellent yields of products, simple reaction conditions and general applicability are the most important advantages of this protocol  

    A simple and novel eco-friendly process for the synthesis of cyclic dithiocarbonates from epoxides and carbon disulfide in water

    , Article Journal of Heterocyclic Chemistry ; Volume 46, Issue 2 , 2009 , Pages 347-350 ; 0022152X (ISSN) Ziyaei Halimehjani, A ; Ebrahimi, F ; Azizi, N ; Saidi, M. R ; Sharif University of Technology
    The reaction of oxiranes with carbon disulfide for preparation of cyclic dithiocarbonates was carried out in water under catalytic amount of an organic base such as dimethylaminopyridine or triethylamine. The reaction conditions are simple and give high yields of desired products.© 2009 HeteroCorporation  

    One-pot Three-component route for the synthesis of functionalized 4H-chromenes catalyzed by ZrOCl2·8H2O in water

    , Article Journal of Heterocyclic Chemistry ; Volume 55, Issue 2 , 2018 , Pages 522-529 ; 0022152X (ISSN) Ziyaei Halimehjani, A ; Keshavarzi, N ; Sharif University of Technology
    HeteroCorporation  2018
    An efficient method for the synthesis of functionalized 4H-chromenes via a one-pot three-component condensation reaction of a 2-hydroxybenzaldehyde with an active methylene compound and a carbon-based nucleophile in the presence of a catalytic amount of ZrOCl2·8H2O in water under thermal condition has been described. High yields, simple work-up procedure, performing reactions in water and synthesis of complex molecules with a one-pot procedure are the main advantages of this procedure. In addition, the structure of the product from the condensation of salicylaldehyde, 2-naphthol, and dimedone was confirmed by X-ray crystallography. © 2018 Wiley Periodicals, Inc  

    Controlled engineering of WS2 nanosheets-CdS nanoparticle heterojunction with enhanced photoelectrochemical activity

    , Article Solar Energy Materials and Solar Cells ; Volume 141 , 2015 , Pages 260-269 ; 09270248 (ISSN) Zirak, M ; Zhao, M ; Moradlou, O ; Samadi, M ; Sarikhani, N ; Wang, Q ; Zhang, H. L ; Moshfegh, A. Z ; Sharif University of Technology
    Elsevier  2015
    Abstract We report the well-controlled preparation of WS2 nanosheets-CdS nanoparticle heterojunction for photoelectrochemical (PEC) water splitting application. The WS2 nanosheets with an average thickness of ~5 nm and lateral dimensions of ~200 nm were synthesized via liquid phase exfoliation of bulk WS2 in water/ethanol solution, followed by deposition onto ITO substrate via electrophoretic method. CdS nanoparticles were grown via facile successive ion layer absorption and reaction (SILAR) method. Using these two well-controlled methods, CdS/WS2/ITO and WS2/CdS/ITO systems were fabricated. The loading of WS2 nanosheets was... 

    Formation mechanism of bead-chain-like ZnO nanostructures from oriented attachment of Zn/ZnO nanocomposites prepared via DC arc discharge in liquid

    , Article Materials Science in Semiconductor Processing ; Volume 72 , 2017 , Pages 128-133 ; 13698001 (ISSN) Ziashahabi, A ; Poursalehi, R ; Naseri, N ; Sharif University of Technology
    Bead-chain-like ZnO nanoparticles (NPs) formed in colloidal solution from oriented attachment (OA) of spherical nanoparticles. Arc discharge in liquid is a cost-effective method for quick mass production of nanostructured materials without considerable environmental footprints. Applying voltage across two zinc rods as electrodes, which were immersed in water cause explosion of electrodes and plasma generation. Zn/ZnO nanocomposites produced by interaction of different active species in high-pressure and high-temperature plasma at the solid-liquid interface. Different sized nanoparticles with diameters of 26, 35, 40 and 60 nm at applied discharge currents of 150, 100, 50 and 20 A... 

    Shed light on submerged DC arc discharge synthesis of low band gap gray Zn/ZnO nanoparticles: Formation and gradual oxidation mechanism

    , Article Advanced Powder Technology ; Volume 29, Issue 5 , 2018 , Pages 1246-1254 ; 09218831 (ISSN) Ziashahabi, A ; Poursalehi, R ; Naseri, N ; Sharif University of Technology
    Elsevier B.V  2018
    Synthesis of colloidal metal oxides with controllable size and morphology is burgeoning field of research in nanoscience. Low band gap gray Zn/ZnO colloidal nanoparticles were fabricated by plasma-liquid interaction of DC arc discharge in water. Scanning electron microscopy, X-ray diffraction and UV–vis spectroscopy were employed for morphology, crystal structure and optical characterizations respectively. Optical emission spectroscopy was used to investigate the plasma properties during the synthesis and formation mechanism of nanoparticles. Nanoparticles with different size and shape were fabricated only by adjusting discharge current during synthesis without introducing any chemical... 

    The effect of silver oxidation on the photocatalytic activity of Ag/ZnO hybrid plasmonic/metal-oxide nanostructures under visible light and in the dark

    , Article Scientific Reports ; Volume 9, Issue 1 , 2019 ; 20452322 (ISSN) Ziashahabi, A ; Prato, M ; Dang, Z ; Poursalehi, R ; Naseri, N ; Sharif University of Technology
    Nature Publishing Group  2019
    A new synergetic hybrid Ag/ZnO nanostructure was fabricated which is able to cause photocatalytic degradation (in high yields) of methylene blue under visible light as well as in the dark. In this nanostructure, ZnO was synthesized using the arc discharge method in water and was coupled with Ag via a chemical reduction method. X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy results confirmed the existence of defects in ZnO in the hybrid nanostructures; these defects act as electron traps and inhibit the recombination of electron-hole pairs. The absorption edge of the hybrid nanostructure shifts toward the visible region of the spectrum due to a combination of the Ag... 

    Shed light on defect induced enhanced visible-light photocatalysis activity of rutile TiO2 nanoparticles: effects of annealing on blue-gray to light–gray transition

    , Article Journal of Materials Research and Technology ; Volume 17 , 2022 , Pages 2400-2409 ; 22387854 (ISSN) Ziashahabi, A ; Poursalehi, R ; Naseri, N ; Peymani, R ; Sharif University of Technology
    Elsevier Editora Ltda  2022
    Preparation of the defective TiO2 nanoparticles (NPs) have been recently in particular interest for its outstanding applications in visible-light active photocatalysis. In order to make TiO2 visible-light absorber, optical band gap should be modified especially via introducing structural defects like oxygen vacancies as an effective pathway. In this research, we prepared defective rutile TiO2 NPs with highly efficient photocatalytic activity under visible light. The NPs were synthesized by electric arc discharge in water as a cost-effective and environmentally friendly method with capability of defect formation which followed by heat treatment. The photocatalytic activity improvement... 

    Mass measurements of isolated objects from space-based microlensing

    , Article Astrophysical Journal ; Volume 825, Issue 1 , 2016 ; 0004637X (ISSN) Zhu, W ; Calchi Novati, S ; Gould, A ; Udalski, A ; Han, C ; Shvartzvald, Y ; Ranc, C ; Jorgensen, U. G ; Poleski, R ; Bozza, V ; Beichman, C ; Bryden, G ; Carey, S ; Gaudi, B. S ; Henderson, C. B ; Pogge, R. W ; Porritt, I ; Wibking, B ; Yee, J. C ; Pawlak, M ; Szymański, M. K ; Skowron, J ; Mróz, P ; Kozłowski, S ; Wyrzykowski, Ł ; Pietrukowicz, P ; Pietrzyński, G ; Soszyński, I ; Ulaczyk, K ; Choi, J. Y ; Park, H ; Jung, Y. K ; Shin, I. G ; Albrow, M. D ; Park, B. G ; Kim, S. L ; Lee, C, U ; Cha, S. M ; Kim, D. J ; Lee, Y ; Friedmann, M ; Kaspi, S ; Maoz, D ; Hundertmark, M ; Street, R. A ; Tsapras, Y ; Bramich, D. M ; Cassan, A ; Dominik, M ; Bachelet, E ; Dong, S ; Jaimes, R. F ; Horne, K ; Mao, S ; Menzies, J ; Schmidt, R ; Snodgrass, C ; Steele, I. A ; Wambsganss, J ; Skottfelt, J ; Andersen, M. I ; Burgdorf, M. J ; Ciceri, S ; D'Ago, G ; Evans, D. F ; Gu, S. H ; Hinse, T. C ; Kerins, E ; Korhonen, H ; Kuffmeier, M ; Mancini, L ; Peixinho, N ; Popovas, A ; Rabus, M ; Rahvar, S ; Tronsgaard, R ; Scarpetta, G ; Southworth, J ; Surdej, J ; Essen, C. V ; Wang, Y. B ; Wertz, O ; Sharif University of Technology
    Institute of Physics Publishing  2016
    We report on the mass and distance measurements of two single-lens events from the 2015 Spitzer microlensing campaign. With both finite-source effect and microlens parallax measurements, we find that the lens of OGLE-2015-BLG-1268 is very likely a brown dwarf (BD). Assuming that the source star lies behind the same amount of dust as the Bulge red clump, we find the lens is a 45 ±7 BD at 5.9 ±1.0 kpc. The lens of of the second event, OGLE-2015-BLG-0763, is a 0.50 ±0.04 star at 6.9 ±1.0 kpc. We show that the probability to definitively measure the mass of isolated microlenses is dramatically increased once simultaneous ground- and space-based observations are conducted  

    Highly efficient of molybdenum trioxide-cadmium titanate nanocomposites for ultraviolet light photocatalytic and antimicrobial application: Influence of reactive oxygen species

    , Article Journal of Photochemistry and Photobiology B: Biology ; Volume 191 , 2019 , Pages 75-82 ; 10111344 (ISSN) Zhu, J. M ; Hosseini, M ; Fakhri, A ; Salari Rad, S ; Hadadi, T ; Nobakht, N ; Sharif University of Technology
    Elsevier B.V  2019
    In the present work we report the enhanced UV light photocatalytic performance of cadmium titanate photocatalyst by MoO 3 for Drug pollutant degradation. The nano photocatalyst sample was synthesized employing the Pechini-ultrasonic-hydrothermal route. Therefore, the nano photocatalyst were characterized by various analytical devices. The wide scan X-ray photoelectron spectral study confirmed the MoO 3 in the CdTiO 3 matrix. The crystallite size calculated with the Debye-Scherrer equation (55.4, 57.0, 61.2 and 63.1 nm for pure CdTiO 3 , MoCdTi-0, MoCdTi-1, and MoCdTi-2 nanocomposites, respectively). SEM micrographs revealed nanowire morphology indicated the crystalline nature of the sample.... 

    Cooling+Heating flows in galaxy clusters: Turbulent heating, spectral modeling, and cooling efficiency

    , Article Astrophysical Journal ; Volume 884, Issue 1 , 2019 ; 0004637X (ISSN) Zhoolideh Haghighi, M. H ; Afshordi, N ; Khosroshahi, H. G ; Sharif University of Technology
    Institute of Physics Publishing  2019
    The discrepancy between expected and observed cooling rates of X-ray emitting gas has led to the cooling-flow problem at the cores of clusters of galaxies. A variety of models have been proposed to model the observed X-ray spectra and resolve the cooling-flow problem, which involves heating the cold gas through different mechanisms. As a result, realistic models of X-ray spectra of galaxy clusters need to involve both heating and cooling mechanisms. In this paper, we argue that the heating timescale is set by the magnetohydrodynamic (MHD) turbulent viscous heating for the Intracluster plasma, parameterized by the Shakura-Sunyaev viscosity parameter, α. Using a cooling+heating flow model, we...