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    Authors’ reply to a comment on M. pasdar et al article

    , Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 561 , 2019 , Pages 407-408 ; 09277757 (ISSN) Pasdar, M ; Kazemzadeh, E ; Kamari, E ; Ghazanfari, M. H ; Soleymani, M ; Sharif University of Technology
    Elsevier B.V  2019

    Molecular dynamics study of bio-manipulation in aqueous media

    , Article Micro and Nano Letters ; Volume 11, Issue 1 , 2016 , Pages 9-14 ; 17500443 (ISSN) Kheirodin, M ; Pishkenari, H. N ; Mahboobi, S. H ; Sharif University of Technology
    Institution of Engineering and Technology  2016
    Nano-manipulation is one of the most important aspects of nano-robotics and nano-assembly. The positioning process is considered by many researches to be one of the most important parts of nano-assembly, but has been poorly investigated, particularly for biologic samples. This Letter is devoted to modelling the process of positioning a biomolecule with atomic force microscopy (AFM) in an aqueous media using molecular dynamics simulations. Carbon nanotube (CNT) and graphite sheet are selected as AFM tip and substrate, respectively. To consider the effects of the medium on the manipulation, several models for decreasing the calculations including implicit, coarse grained, and all-atom methods... 

    Harmful algal blooms (red tide): a review of causes, impacts and approaches to monitoring and prediction

    , Article International Journal of Environmental Science and Technology ; Volume 16, Issue 3 , 2019 , Pages 1789-1806 ; 17351472 (ISSN) Zohdi, E ; Abbaspour, M ; Sharif University of Technology
    Center for Environmental and Energy Research and Studies  2019
    Red tide, an impermanent natural phenomenon including harmful algal blooms, causes changing the color of the sea generally to red or almost brown, and has a serious impact on environment along the coast and aquatic ecosystem. Due to recent extensive steady harmful algal blooms events that cause adverse impacts on human healthsome, aquaculture and tourism industry, and the entire economy of the coastal region, the need of society for realizing these phenomena is much greater than the past. In the recent decades, consideration of algal blooms and determination of bloom-former species and fundamental researches about dynamics of blooms are increased worldwide. Development in technology has... 

    Effects of electrophoretic deposition parameters on the photocatalytic activity of TiO2 films: Optimization by response surface methodology

    , Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Vol. 452, Issue. 1 , 2014 , pp. 1-8 ; ISSN: 09277757 Mohammadi, M. M ; Vossoughi, M ; Feilizadeh, M ; Rashtchian, D ; Moradi, S ; Alemzadeh, I ; Sharif University of Technology
    In this work, the electrophoretic deposition method was utilized to immobilize TiO2 particles on stainless steel substrates. In addition, for the first time, statistics-based experimental design using response surface methodology was employed to investigate the effect of four key coating parameters (i.e. applied voltage, calcination temperature, photocatalyst weight percentage, and deposition time) on the photocatalytic degradation. Analysis of variance revealed that the proposed model was adequate. X-ray diffraction and scanning electron microscope were used to evaluate the effects of the parameters on degradation efficiency. The optimum applied voltage, calcination temperature, catalyst... 

    Modification of rock/fluid and fluid/fluid interfaces during MEOR processes, using two biosurfactant producing strains of Bacillus stearothermophilus SUCPM#14 and Enterobacter cloacae: A mechanistic study

    , Article Colloids and Surfaces B: Biointerfaces ; Vol. 117 , May , 2014 , pp. 457-465 ; ISSN: 09277765 Sarafzadeh, P ; Zeinolabedini Hezave, A ; Mohammadi, S ; Niazi, A ; Ayatollahi, S ; Sharif University of Technology
    During any microbial enhanced oil recovery process, both cells and the metabolic products of bacteria govern the tertiary oil recovery efficiency. However, very accurate examination is needed to find the functionality of these tiny creatures at different reservoir conditions. In this regard, the effect of cell structure on ultimate microbial recovery efficiency which is the most dominant mechanism based on the microorganism types (gram-negative or gram-positive) was systematically investigated. At the first stage, possible different active mechanisms using Bacillus stearothermophilus SUCPM#14 strain were tested using specially designed injection protocol, in situ and ex situ core flooding... 

    New gasochromic system: Nanoparticles in liquid

    , Article Journal of Nanoparticle Research ; Volume 14, Issue 4 , March , 2012 ; 13880764 (ISSN) Ranjbar, M ; Kalhori, H ; Mahdavi, S. M ; Zad, A. I ; Sharif University of Technology
    In this study, WO 3 nanocrystallites were first produced by laser ablation of W target in deionised water. To synthesize palladium, a PdCl 2 solution (0.2 g/L) was added to the liquid. Transmission electron microscope revealed successful synthesis of tungsten oxide nanocrystallites along with the production of Pd and core-shell Pd/WO3 nanoparticles. Gasochromic behavior was examined by hydrogen bubbling into Pd/WO 3 liquid in which a transition to blue absorbing state was observed. Optical absorption spectra of the colored liquid represented different sharp small polaron absorbing peaks below 3 eV and the peaks intensity was observed to be varied with Pd:WO 3 ratio. Time variations of... 

    Nanoparticles migration due to thermophoresis and Brownian motion and its impact on Ag-MgO/water hybrid nanofluid natural convection

    , Article Powder Technology ; Volume 375 , 20 September , 2020 , Pages 493-503 Goudarzi, S ; Shekaramiz, M ; Omidvar, A ; Golab, E ; Karimipour, A ; Karimipour, A ; Sharif University of Technology
    Elsevier B.V  2020
    The present study aims to investigate the impact of nanoparticle migration due to Brownian motion and thermophoresis on Ag-MgO/Water hybrid nanofluid natural convection. An enclosure with sinusoidal wavy walls is considered for this investigation; right and cold walls of this enclosure are in constant temperature while the upper and bottom walls are insulated. This simulation follows Buongiorno's mathematical model; Brownian and thermophoresis diffusion of Ag occurs in MgO-Water nanofluid while the diffusion of MgO happens in Ag-water nanofluid. The result indicates that Nu number increments up to 11% by increasing thermophoresis diffusion for both nanoparticles. Also, increasing Brownian... 

    New proline, alanine, serine repeat sequence for pharmacokinetic enhancement of anti-vegf single-domain antibody

    , Article Journal of Pharmacology and Experimental Therapeutics ; Volume 375, Issue 1 , July , 2020 , Pages 69-75 Khodabakhsh, F ; Salimian, M ; Mehdizadeh, A ; Khosravy, M. S ; Vafabakhsh, A ; Karami, E ; Cohan, R. A ; Sharif University of Technology
    American Society for Pharmacology and Experimental Therapy  2020
    Therapeutic fragmented antibodies show a poor pharmacokinetic profile that leads to frequent high-dose administration. In the current study, for the first time, a novel proline, alanine, serine (PAS) repeat sequence called PAS#208 was designed to extend the plasma half-life of a nanosized anti-vascular endothelial growth factor-A single-domain antibody. Polyacrylamide gel electrophoresis, circular dichroism, dynamic light scattering, and electrophoretic light scattering were used to assess the physicochemical properties of the newly designed PAS sequence. The effect of PAS#208 on the biologic activity of a single-domain antibody was studied using an in vitro proliferation assay. The... 

    Determining of the optimized dimensions of the Marinelli beaker containing source with inhomogeneous emission rate by using genetic algorithm coupled with MCNP and determining distribution type by neural networks

    , Article Applied Radiation and Isotopes ; Volume 157 , 2020 Zamzamian, S. M ; Hosseini, S. A ; Feghhi, S. A ; Samadfam, M ; Sharif University of Technology
    Elsevier Ltd  2020
    In order to determine the activity of C137s in soil resulting from nuclear accidents or fallouts, the best choice is to use HPGe detectors due to their best energy resolutions. In this regard, in order to enhance the detection efficiency, the Marinelli beakers have been used to increase the radiation interaction with the sensitive volume of the detector. In previous works, to optimize the dimension of Marinelli beakers, the assumption was that the emission rate of the source is homogeneous in beaker volume. In the present study, to investigate the effect of the inhomogeneous emission rate of the source on the optimum dimensions of the beaker, in a simple case, the beaker was divided into two... 

    Model development for MEOR process in conventional non-fractured reservoirs and investigation of physico-chemical parameter effects

    , Article Chemical Engineering and Technology ; Volume 31, Issue 7 , 2008 , Pages 953-963 ; 09307516 (ISSN) Behesht, M ; Roostaazad, R ; Farhadpour, F ; Pishvaei, M. R ; Sharif University of Technology
    A three-dimensional multi-component transport model in a two-phase oil-water system was developed. The model includes separated terms to account for the dispersion, convection, injection, growth and death of microbes, and accumulation. For the first time, effects of both wettability alteration of reservoir rock from oil wet to water wet and reduction in interfacial tension (IFT) simultaneously on relative permeability and capillary pressure curves were included in a MEOR simulation model. Transport equations were considered for the bacteria, nutrients, and metabolite (bio-surfactant) in the matrix, reduced interfacial tension on phase trapping, surfactant and polymer adsorption, and effect... 

    Towards greater mechanical, thermal and chemical stability in solid-phase microextraction

    , Article TrAC - Trends in Analytical Chemistry ; Volume 34 , 2012 , Pages 126-138 ; 01659936 (ISSN) Bagheri, H ; Piri-Moghadam, H ; Naderi, M ; Sharif University of Technology
    Solid-phase microextraction (SPME) is a fast, solvent-free technique, which, since its introduction in the 1990s, has been increasingly applied to sample preparation in analytical chemistry. Conventional SPME fibers are fabricated by making a physical bond between the usual silica substrate and the polymeric coatings. However, some applications are limited, as the lifetime and the stability of conventional SPME fibers cannot meet the demands of analyzing relatively non-volatile compounds with more polar moieties. There have been attempts to analyze less volatile compounds by increasing the thermal, physical and chemical stability of the fibers. In this review, we present some new... 

    Fabrication of porous gelatin-chitosan microcarriers and modeling of process parameters via the RSM method

    , Article International Journal of Biological Macromolecules ; Volume 88 , 2016 , Pages 288-295 ; 01418130 (ISSN) Karimian, S. A. M ; Mashayekhan, S ; Baniasadi, H ; Sharif University of Technology
    Elsevier B.V 
    Porous gelatin-chitosan microcarriers (MCs) with the size of 350 ± 50 μm were fabricated with blends of different gelatin/chitosan (G/C) weight ratio using an electrospraying technique. Response surface methodology (RSM) was used to study the quantitative influence of process parameters, including blend ratio, voltage, and syringe pump flow rate, on MCs diameter and density. In the following, MCs of the same diameter and different G/C weight ratio (1, 2, and 3) were fabricated and their porosity and biocompatibility were investigated via SEM images and MTT assay, respectively. The results showed that mesenchymal stem cells (MSCs) could attach, proliferate, and spread on fabricated porous MCs... 

    Synthesis of cellulose acetate/chitosan/SWCNT/Fe3O4/TiO2 composite nanofibers for the removal of Cr(VI), As(V), Methylene blue and Congo red from aqueous solutions

    , Article International Journal of Biological Macromolecules ; Volume 140 , 2019 , Pages 1296-1304 ; 01418130 (ISSN) ZabihiSahebi, A ; Koushkbaghi, S ; Pishnamazi, M ; Askari, A ; Khosravi, R ; Irani, M ; Sharif University of Technology
    Elsevier B.V  2019
    The potential of electrospun cellulose acetate/chitosan/single walled carbon nanotubes/ferrite/titanium dioxide (CA/chitosan/SWCNT/Fe3O4/TiO2) nanofibers was investigated for the removal of Cr(VI), As(V), Methylene blue and Congo red from aqueous solutions via the adsorption and photocatalytic reduction processes. The properties of synthesized SWCNT/Fe3O4/TiO2 and fibers were characterized using TEM, SEM, FTIR, XRD, TGA and BET analysis. In adsorption process, the influence of adsorbent type including SWCNT to Fe3O4 ratio, TiO2 to SWCNT/Fe3O4 ratio and SWCNT/Fe3O4/TiO2 concentration as well as the adsorption parameters including pH, contact time, and initial concentration of adsorbates on... 

    A metal organic framework-polyaniline nanocomposite as a fiber coating for solid phase microextraction

    , Article Journal of Chromatography A ; Volume 1431 , 2016 , Pages 27-35 ; 00219673 (ISSN) Bagheri, H ; Javanmardi, H ; Abbasi, A ; Banihashemi, S ; Sharif University of Technology
    Elsevier B. V 
    A metal organic framework-polyaniline (MOF/PANI) nanocomposite was electrodeposited on a stainless steel wire and used as a solid phase microextraction (SPME) fiber coating. The electropolymerization process was carried out under a constant deposition potential and applied to the corresponding aqueous electrolyte containing aniline and MOF particles. The employment of MOFs with their large and small cages and 3-D structures in synthesizing a nanocomposite was assumed to be efficient constitutes to induce more non-smooth and porous structures, approved by scanning electron microscopy (SEM) images. Three different MOFs were incorporated to synthesize the desired nanocomposites and the... 

    Silica aerogel coated on metallic wire by phase separation of polystyrene for in–tube solid phase microextraction

    , Article Journal of Chromatography A ; Volume 1500 , 2017 , Pages 69-75 ; 00219673 (ISSN) Baktash, M. Y ; Bagheri, H ; Sharif University of Technology
    Elsevier B.V  2017
    In this research, an attempt was made toward synthesizing a sol–gel–based silica aerogel and its subsequent coating on a copper wire by phase separation of polystyrene. Adaption of this new approach enabled us to coat the metallic wire with powder materials. The use of this method for coating, led to the formation of a porous and thick structure of silica aerogel. The coated wire was placed in a needle and used as the sorbent for in–tube solid phase microextraction of chlorobenzenes (CBs). The superhydrophobicity of sorbent on extraction efficiency was investigated by using different ratios of tetraethylorthosilicate/methyltrimethoxysilane. The surface coated with the prepared silica aerogel...