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    Synthesis of Hybrid Nano-Adsorbent for CO2 Adsorption

    , M.Sc. Thesis Sharif University of Technology Pourrangbar, Mohammad (Author) ; Molaei Dehkordi, Asghar (Supervisor) ; Rashidi, Ali Moradi (Supervisor)
    CO2 as a green house gas plays a significant role in the global warming and weather changes. Absorption by means of amine solutions is the main industrial technique for separating of CO2 from gas mixtures. Hazards associated with high temperature during solvent recovery, large size of equipment, corrosion, solvent degradation, and other reasons has made researchers to look for alternative processes such as adsorption. The aim of this study was to synthesis and modify the nano adsorbent for CO2 capture. To fulfill this purpose, various nano silica structures were synthesized and the amount of adsorption of each sample was determined. To investigate the performance capability nano_adsorbents,... 

    Study on Factor Involved in Multi-step Two Phase CO2 Sequestration Process

    , Ph.D. Dissertation Sharif University of Technology Hemmati, Azadeh (Author) ; Shaygan Salek, Jalaloddin (Supervisor) ; Kariminia, Hamid Reza (Supervisor)
    The increase in CO2 concentration and its effect on ecosystem and global warming make carbon sequestration inevitable for now and future. Ex-situ carbonation of mineral ores is one of the studied sequestration methods. This method is permanent and safe in comparison with others. This process is carried out in four steps and two phases in this dissertation. At the first stage magnesium was extracted from its mineral silicate ore (Mixture of serpentine and olivine) by hydrochloric acid (HCl) and was dissolved in liquid phase as ion. After that the resultant leachate of extraction step was purified from unwanted ions extracted from minerals in two steps by precipitation formed by increasing pH.... 

    Simulation of biomanipulation using molecular dynamics

    , Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) ; Volume 9, Issue PARTS A AND B , 2012 , Pages 137-143 ; 9780791845257 (ISBN) Pishkenari, H. N ; Mahboobi, S. H ; Mahjour, M. A ; Meghdari, A ; Sharif University of Technology
    In this paper, the simulation of biomolecules manipulation using molecular dynamics (MD) is studied. In order to investigate the manipulation behavior, we have used the ubiquitin as biomolecule, a single-walled carbon nanotube (SWCNT) as manipulation probe, a two-layer graphene sheet as substrate. Along this line, a series of simulations are conducted to study the effects of different conditions on the success of manipulation process. These conditions include tip diameter, vertical gap between the tip and substrate, initial orientation of protein, and the tip position with respect to the biomolecule  

    A novel correlation approach to estimate thermal conductivity of pure carbon dioxide in the supercritical region

    , Article Journal of Supercritical Fluids ; Volume 64 , 2012 , Pages 39-45 ; 08968446 (ISSN) Jarrahian, A ; Heidaryan, E ; Sharif University of Technology
    In this paper, a new correlation to calculate the thermal conductivity of supercritical carbon dioxide based on 668 data points from the literature is introduced. The proposed correlation is valid in temperature range from 310 to 960 K, and pressures range between 7.4 and 210 MPa. The average absolute error of the model was found to be 2.7 and 2.4% in the comparison with the literature and NIST data respectively, which demonstrates superiority of the model over other methods  

    Synthesis of soluble N-functionalized polysaccharide derivatives using phenyl carbonate precursor and their application as catalysts

    , Article Starch/Staerke ; Volume 63, Issue 12 , 2011 , Pages 780-791 ; 00389056 (ISSN) Pourjavadi, A ; Seidi, F ; Afjeh, S. S ; Nikoseresht, N ; Salimi, H ; Nemati, N ; Sharif University of Technology
    Soluble N-functionalized basic and cationic polysaccharides have been synthesized using polysaccharide phenyl carbonate as a precursor. The products and intermediates were thoroughly characterized by conventional methods. The quaternization of amino intermediates in various conditions was studied. Moreover, the potential of basic polymers as green and selective catalysts in Knoevenagel reaction was investigated. In all cases, only one isomer was obtained  

    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  

    Experimental Investigation of Carbonated Water Alternating Nitrogen Gas Injection to Enhance Heavy Oil Recovery From Carbonated Rock Reservoir

    , M.Sc. Thesis Sharif University of Technology Majidi, Mohammad Javad (Author) ; Ghazanfari, Mohammad Hossein (Supervisor) ; Taghikhani, Vahid (Co-Advisor) ; Badakhshan, Amir (Co-Advisor)
    By continuous decreasing the fossil fuel energy resources and increasing demand of such energies on the other hand with decreasing exploration of the new ones, production from these limited resources are in grate consideration. As a few percentages of the oil recovers by primary oil production and also remaining a lot of oil after water and gas injection in the secondary oil recovery process, causes that new methods to increase the oil recovery has been proposed. Water injection is a simple and common method in enhanced oil recovery process. Also water alternating gas injection and simultaneous water and gas injection causes considerable increase in oil recovery. Recently utilization of... 

    Feasibility Study of Using Molten Carbonate Fuel Cell for CO2 Capture from Exhaust Gases of Internal Combustion Engines

    , M.Sc. Thesis Sharif University of Technology Habibzade, Samane (Author) ; Roshandel, Ramin (Supervisor) ; Shaygan, Jalaloddin (Co-Advisor)
    According to, increasing use of energy in the world, issues such as increasing reenhouse gas’ emission, rising temperature on planet earth and air pollution have appeared Carbon dioxide is a major greenhouse gas that has a significant impact on increasing the temperature of earth. In recent years, attentions to carbon dioxide capturring and sequestration technologies have been increased. In this project molten carbonate fuel cell which is used as a new method for separating carbon dioxide from gaseous compounds of combustion process, is discussed. The aim of the project is to, investigate technical and
    economic feasibility of using molten carbonate fuel cell for separating carbon... 

    Synthesis of Transition Metal Nanocatalysts (Pd, Ni, Co) and Their Application in Regioselective Carbon-carbon and Carbon-heteroatom Bond Formation

    , Ph.D. Dissertation Sharif University of Technology Pourkaveh Dehkordi, Raheleh (Author) ; Matloubi Moghaddam, Firouz (Supervisor)
    Due to many vast application of C-C bond formation in the areas including bioactive compounds and natural products, over the past few years, the C-C coupling reactions have become a versatile tool in organic synthesis.First, a two-metal catalyst (CoFe2O4) was synthesized and its catalytic activity was evaluated in unsymmetrical thioether synthesis which offered an odorless, ligand-free and aryl halide-free rout for the formation of desired products. The catalyst was recovarable and was able to catalyze the reaction for 10 runs with retention of catalytic activity.In the next step, three-metal catalyst (CoCuFe2O4) was synthesized using the co-precipitation method and characterized.Then, these... 

    Synthesis of Magnetic Nanocatalysis Based on Polyvinyl Derivatives and the Investigation of their Catalytic Activity in Organic Reactions

    , Ph.D. Dissertation Sharif University of Technology Jarahiyan Sedeh, Atefeh (Author) ; Matloubi Moghaddam, Firouz (Supervisor) ; Pourjavadi, Ali (Supervisor)
    In recent years, the use of various catalysts has become a powerful tool in the synthesis of a wide range of biologically important molecules and or natural products toward the formation of carbon-carbon and carbon-heteroatom bonds. In the first section, the synthesis of magnetic catalyst based on acrylonitrile was reported and an attempt was made to use an efficient support and ligand to immobilize copper metals. Then, its structure was characterized by different techniques. The catalytic activity of the prepared catalyst was confirmed in the formation of indolyl diketones and the desired products were successfully synthesized with good to excellent yields. In addition, the catalyst could... 

    Fabrication, characterization and mechanical properties of hybrid composites of copper using the nanoparticulates of SiC and carbon nanotubes [electronic resource]

    , Article Journal of Materials Science and Engineering: A ; 10 June 2013, Volume 572, P.83–90 Akbarpour, M. R ; Salahi, E ; Alikhani Hesari, F ; Simchi, A. (Abdolreza) ; Kim, H. S ; Sharif University of Technology
    Copper based hybrid composites containing nano-sized silicon carbide and carbon nanotubes reinforcements with minimal porosity were fabricated via mechanical milling followed by hot pressing technique. Microstructures of the powders and consolidated materials were studied using scanning electron microscope, X-ray diffraction, Raman spectroscopy, and scanning transmission electron microscope. Microstructural characterization of the materials revealed that the addition of nanosized silicon carbide reinforcement lowered the grain growth rate and enhanced the homogenization during mechanical milling. Microhardness measurements and compression test showed considerable improvements in mechanical... 

    Formation of carbon nanotubes in Iron-catalyzed arcing method: Effect of iron-ion charge in the aqueous medium [electronic resource]

    , Article International Journal of Modern Physics B Condensed Matter Physics; Statistical Physics; Atomic, Molecular and Optical Physics ; 30 December 2011, Volume 25, Issue 32, PP. 4411-4417 Shervin, Sh ; Gheytani, S ; Simchi, A. (Abdolreza) ; Sharif University of Technology
    Carbon nanotubes (CNTs) were synthesized via arc discharge in aqueous solutions containing ferrous and ferric irons to reveal the effect of iron-charge mole ratio, R = [Fe2+]/[Fe3+], on the purity of CNTs and the process yield. Raman spectroscopy and transmission electron microscopy were used to analyze the cathodic deposits. It is shown that the nucleation of multi-walled CNTs is catalyzed by ferric irons while their growth is affected by ferrous ions. Well-graphitized CNTs with a high-yield are obtained at R = 1 and total iron concentration of 0.05 M. The effect of iron charge is described based on the two-stage formation mechanism  

    On the formation of SWCNTs and MWCNTs by Arc-discharge in aqueous solutions: the role of iron charge and counter ions [electronic resource]

    , Article Journal of Fullerenes, Nanotubes and Carbon Nanostructures ; 2011, Volume 19, Issue 4, Pages 317-328 Gheytani, S ; Shervin, Sh ; Simchi, A. (Abdolreza) ; Sharif University of Technology
    Single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) were synthesized in aqueous solutions containing FeCl2, FeCl3, FeSO4 and Fe2(SO4)3. The effects of iron charge and the counter ions on the formation of carbon nanotubes (CNTs) were investigated. Thermogravimetric (TG) analysis indicated that carbon multilayer structures including CNTs and multishell graphite particles were formed in deionized (DI) water without the iron precursor. SWCNTs were also synthesized in the presence of the iron ions. It was also found that the mole ratio of [Fe2+]/[Fe3+] in the solution has a significant influence on the purity of CNTs and the process yield. The highest yield was... 

    Horseradish peroxidase immobilization on amine functionalized carbon nanotubes: direct electrochemistry and bioelectrocatalysis

    , Article Progress in Reaction Kinetics and Mechanism ; Volume 37, Number 2 , 2012 , pp. 161-172 Tasviri, M. (Mahboubeh) ; Ghourchian, H. (Hedayatollah) ; Gholami, M. R. (Mohammad Reza) ; Rafieepour, H. A. (Hossain Ali) ; Sharif University of Technology
    Horseradish peroxidase (HRP) was successfully immobilized on amine functionalized TiO2-coated multiwalled carbon nanotubes (NH2 – TiO2 – CNTs) by a convenient and efficient method. Electrochemical impedance spectroscopy, cyclic voltammetry and amperometry were applied to characterize the HRP/NH2 – TiO2 – CNT nano-composite. These techniques showed that the NH2 – TiO2 – CNTs greatly enhance the electron transfer between HRP and the modified electrode. Owing to the redox reaction of the electroactive centre of HRP, the HRP = NH2 – TiO2 – CNTs modified electrode exhibited a pair of quasi-reversible peaks with a peak-to-peak separation (ΔEp) of 70.6 mV and a formal potential (E 0′) of 367.65 mV... 

    Hydro-purification of crude terephthalic acid using palladium catalyst supported on multi-wall carbon nanotubes

    , Article Journal of Industrial and Engineering Chemistry ; 2015 ; ISSN: 1226086X Tourani, S ; Khorasheh, F ; Rashidi, A. M ; Safekordi, A. A ; Sharif University of Technology
    Palladium catalysts supported on functionalized multi-wall carbon nanotubes were synthesized for hydro-purification of crude terephthalic acid containing 2100ppm 4-carboxybenzaldehyde (4-CBA) as impurity. PdCl2 and Pd(OAc)2 were used as precursors. Palladium loadings were 0.05 to 0.6wt.% with catalysts reduced at 200 to 400°C. Catalysts prepared from both precursors with least 0.3wt.% palladium resulted in 99%+ removal of 4-CBA. The most desired selectivity was obtained for the catalyst with PdCl2 as precursor, reduction temperature of 300°C, and palladium loading of 0.3wt.%. This catalyst had slightly better performance than the commercial catalyst (0.5wt.% of palladium on activated carbon)... 

    Cytotoxicity of carbon nanotube/polycitric acid hybrid nanomaterials

    , Article Iranian Polymer Journal (English Edition) ; Vol. 23, issue. 3 , 2014 , pp. 195-201 ; ISSN: 10261265 Adeli, M ; Alavidjeh, M. S ; Mohammadifar, E ; Sharif University of Technology
    Polycitric acid was conjugated onto the surface of carbon nanotubes (CNTs), and hybrid nanomaterials containing CNT axis and polycitric acid branches that were highly soluble in aqueous solutions were synthesized. In this work, pristine MWCNTs were opened and functionalized through treatment with acid, then polycitric acid was covalently grafted onto their surface by the "grafting from" approach based on polycondensation of citric acid in the melting state. The chemical structure, morphology, thermal properties and size of MWCNT-g-PCA hybrid materials were investigated by IR, 13C NMR, 1H NMR, TEM, TGA, DSC and DLS. To investigate the biocompatibility of the synthesized hybrid nanomaterials... 

    Carbon nanotube-based nano-fluidic devices

    , Article Journal of Physics D: Applied Physics ; Vol. 47, issue. 8 , 2014 ; ISSN: 00223727 Masoud Seyyed Fakhrabadi, M ; Rastgoo, A ; Ahmadian, M. T ; Sharif University of Technology
    The paper investigates the influences of fluid flow on static and dynamic behaviours of electrostatically actuated carbon nanotubes (CNTs) using strain gradient theory. This nonclassical elasticity theory is applied in order to obtain more accurate results possessing higher agreement with the experimental data. The effects of various fluid parameters such as the fluid viscosity, velocity, mass and temperature on the pull-in properties of the CNTs with two cantilever and doubly clamped boundary conditions are studied. The results reveal the applicability of the proposed nano-system as nano-valves or nano-fluidic sensors  

    Nonlinear analysis of carbon nanotube-based nanoelectronics devices

    , Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Vol. 228, issue. 13 , 2014 , p. 2426-2439 Fakhrabadi, M. M. S ; Rastgoo, A ; Ahmadian, M. T ; Sharif University of Technology
    The paper deals with the investigation of nonlinear static and dynamic behaviors of electrostatically actuated carbon nanotubes with different geometries and boundary conditions. The deflection and pull-in properties are studied in detail in the presence of DC and combined DC+AC electrostatic voltages accompanying the interatomic interactions. The considered nano system can be applied in a wide range of nanoelectronics devices such as nano switches, nano resonators, nano transistors, nano capacitors and random access memories. Moreover, a useful mathematical model of the nano sensor application of the studied nano system to sense the stiffness of the nano particles is presented  

    Investigation of the electrochemical behavior of mesalazine on the surface of a glassy carbon electrode modified with CNT/PPY doped by 1,5-naphthalenedisulfonic acid

    , Article Electroanalysis ; Volume 25, Issue 11 , 2013 , Pages 2481-2491 ; 10400397 (ISSN) Shahrokhian, S ; Hosseini, P ; Kamalzadeh, Z ; Sharif University of Technology
    A glassy carbon electrode (GCE) was modified with a thin layer of multiwalled carbon nanotubes (MWCNTs) and subsequently, electrochemically deposited poly-pyrrole. The electrochemical behavior of mesalazine was studied on the surface of the modified electrode by applying linear sweep voltammetry (LSV). The electropolymerization process and the electrochemical response toward mesalazine were investigated in the presence of different aromatic anion dopants including, benzenesulfonic acid (BSA), 1,3-benzenedisulfonic acid (1,3-BDSA), 1,5-naphthalenedisulfonic acid (1,5-NDSA) and new coccine (NC). By using 1,5-NDSA as dopant, a significant increase (~418 times) in the peak current of mesalazine... 

    A numerical investigation on the free vibration of carbon nanopeapods as variable frequency beam resonators

    , Article Modern Physics Letters B ; Volume 27, Issue 21 , August , 2013 ; 02179849 (ISSN) Firouz Abadi, R. D ; Alavi, S. M ; Sharif University of Technology
    This study aims at investigation of the resonance frequencies of carbon nanopeapods constructed by a single wall carbon nanotube and encapsulated buckyball molecules (C60). A nanopeapod can be used as a nanoscale variable frequency beam resonator according to the number and positions of the encapsulated fullerenes. Using the molecular structural mechanics method the covalence bonds are simulated by equivalent beam elements and the van der Waal interactions between the buckyballs and nanotube are modeled as linear springs. Also, an equivalent beam model is proposed for the nanopeapod with sectional properties which are obtained by the molecular structural mechanics model. The beam-like modes...