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    Metallurgical challenges in carbon nanotube-reinforced metal matrix nanocomposites

    , Article Metals ; Volume 7, Issue 10 , 2017 ; 20754701 (ISSN) Azarniya, A ; Safavi, M. S ; Sovizi, S ; Azarniya, A ; Chen, B ; Madaah Hosseini, H. R ; Ramakrishna, S ; Sharif University of Technology
    Abstract
    The inclusion of carbon nanotubes (CNTs) into metallic systems has been the main focus of recent literature. The aim behind this approach has been the development of a new property or improvement of an inferior one in CNT-dispersed metal matrix nanocomposites. Although it has opened up new possibilities for promising engineering applications, some practical challenges have restricted the full exploitation of CNTs’ unique characteristics. Non-uniform dispersion of CNTs in the metallic matrix, poor interfacial adhesion at the CNT/metal interface, the unfavorable chemical reaction of CNTs with the matrix, and low compactability are the most significant challenges, requiring more examination.... 

    Optimizing carbonaceous nanostructure composition as a substrate to grow co electrocatalysts

    , Article Iranian Journal of Physics Research ; Volume 17, Issue 5 , 2018 , Pages 753-760 ; 16826957 (ISSN) Pourreza, M ; Naseri, N ; Ghasemi, S ; Sharif University of Technology
    Isfahan University of Technology  2018
    Abstract
    Global warming and other adverse environmental effects of fossil fuels have forced humans to consider clean and renewable energy resources. In this context, hydrogen production from water splitting reaction is a key approach. In order to reduce required overpotential for water oxidation reaction, it is necessary to use low cost and earth abundant electrocatalysts like Co, Cu, Fe, Mn, Ni and Zn nanostructures. Herein, cobalt nanostructures on steel-mesh substrate were applied. Electrochemical method was used for growth of Co nanoflakes because of its simplicity and scalability for commercial approach. On the other hand, using carbonaceous support layers including nanomaterials such as... 

    Nanostructured ternary composites of PPy/CNT/NiFe2O4 and PPy/CNT/CoFe2O4: Delineating and improving microwave absorption

    , Article Comptes Rendus Chimie ; Volume 21, Issue 9 , 2018 , Pages 862-871 ; 16310748 (ISSN) Ghashghaei, E ; Kheirjou, S ; Asgari, S ; Kazerooni, H ; Sharif University of Technology
    Elsevier Masson SAS  2018
    Abstract
    Two different ternary nanocomposites, PPy/CNT/CoFe2O4 and PPy/CNT/NiFe2O4, were synthesized by in situ polymerization method. The resulting composites were characterized using Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. They were evaluated with the aim of investigating microwave absorption properties. The results showed that the value of microwave reflection decreases as that of prepared nanocomposites increases. This happens with increase in the PPy content and polymerization on the surface. © 2018 Académie des sciences  

    Hybrid nano-adsorbent supported carbon dots for removal of chromium from aqueous solution

    , Article Desalination and Water Treatment ; Volume 103 , 2018 , Pages 221-231 ; 19443994 (ISSN) Eslami, A ; Borghei, S. M ; Rashidi, A ; Takdastan, A ; Sharif University of Technology
    Desalination Publications  2018
    Abstract
    In this study, hybrid nano adsorbent supported carbon dots was prepared and used for removing Cr(VI) from aqueous solution. Carbon dots were synthesized from sugarcane molasses under microwave irradiation. Hybrid nano adsorbent was prepared by impregnating carbon dot with H3PO4 in a ratio of 2:1 and introducing 0.01 M FeCl3 into the slurry. The carbon dot hybrid was activated via a conventional thermal method under N2 flow. The physico-chemical properties of the synthesized material were investigated using X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption/desorption, and field emission scanning electron microscopy (FESEM). Chromium adsorption was studied... 

    Conjugation of amphotericin B to carbon nanotubes via amide-functionalization for drug delivery applications

    , Article Engineering Letters ; Volume 17, Issue 4 , 2009 ; 1816093X (ISSN) Vossoughi, M ; Gojgini, S ; Kazemi, A ; Alemzadeh, I ; Zeinali, M ; Sharif University of Technology
    2009
    Abstract
    Carbon nanotubes are among promising components for a wide range of applications, due to their unique properties; Specifically, They are a new alternative and efficient tool for transporting and translocating therapeutic molecules since they can translocate easily into the cytoplasm or nucleus of a cell through its membrane without generating an immunogenic response and toxic effects. While pristine carbon nanotubes are insoluble in all solvents, the organic functionalisation of carbon nanotubes is the prerequisite for their solubility profiles and their manipulation into biological systems. For this purpose, in this study, we first report the Amide-functionalization of CNTs which a direct... 

    Novel structures for carbon nanotube field effect transistors

    , Article International Journal of Modern Physics B ; Volume 23, Issue 19 , 2009 , Pages 3669-3678 ; 02179792 (ISSN) Faez, R ; Hosseini, S. E ; Sharif University of Technology
    2009
    Abstract
    A carbon nanotube field effect transistor (CNTFET) has been studied based on the SchrödingerPoisson formalism. To improve the saturation range in the output characteristics, new structures for CNTFETs are proposed. These structures are simulated and compared with the conventional structure. Simulations show that these structures have a wider output saturation range. With this, larger drain-source voltage (Vds) can be used, which results in higher output power. In the digital circuits, higher Vds increases noise immunity. © 2009 World Scientific Publishing Company  

    Cold-Briquetted iron and carbon (CBIC): investigation of the influence of environmental condition on its chemical and physical properties

    , Article Journal of Sustainable Metallurgy ; Volume 5, Issue 4 , 2019 , Pages 497-509 ; 21993823 (ISSN) Paknahad, P ; Askari, M ; Shahahmadi, S. A ; Sharif University of Technology
    Springer  2019
    Abstract
    In this study, a comprehensive investigation was carried out on the effects of environmental condition on physical and chemical properties of Cold-Briquetted Iron and Carbon (CBIC), Cold Direct Reduced Iron (CDRI), and Hot-Briquetted Iron (HBI). The results showed that cold briquetting of CDRI decreases its specific surface area by 51%, which has a significant effect on its oxidation resistance and mechanical strength. Microscopic observations revealed that the oxidation products are formed in near-surface porosities during aging, which protects the fresh material underneath from environmental oxidants, resulting in retarding further oxidation. The oxidation behavior of the samples showed... 

    Design and experimental development of hexapod robot with fiberglass-fibercarbon composite legs

    , Article 6th RSI International Conference on Robotics and Mechatronics, IcRoM 2018, 23 October 2018 through 25 October 2018 ; 2019 , Pages 439-444 ; 9781728101279 (ISBN) Kebritchi, A ; Havashinezhadian, S ; Rostami, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    Over the last few years, the universal number of legged robots has increased astonishingly in outdoor environments. In this paper, the design, and control of a new RHex robot named IRHex with innovative Fiberglass-Fiber carbon composite legs are described. IRHex is a six-legged robot-one actuator located at each hip-achieving mechanical uncomplicatedness that provides a reliable performance. In this investigation, the new material used for building IRHex legs was discovered after several tests on the effect of sequence and orientation of laminates in the composite. IRHex achieves robust locomotion using a computer board analyzing the data sent by the sensors and communicating to the ground... 

    Photoluminescent carbon quantum dot/poly-L-Lysine core-shell nanoparticles: A novel candidate for gene delivery

    , Article Journal of Drug Delivery Science and Technology ; 2020 Hasanzadeh, A ; Mofazzal Jahromi, M. A ; Abdoli, A ; Mohammad Beigi, H ; Fatahi, Y ; Nourizadeh, H ; Zare, H ; Kiani, J ; Radmanesh, F ; Rabiee, N ; Jahani, M ; Mombeiny, R ; Karimi, M ; Sharif University of Technology
    Editions de Sante  2020
    Abstract
    Cationic polymers such as poly-L-lysine (PLL) are able to interact electrostatically with DNA to produce polymeric systems with nanometric diameters due to the neutralization and accumulation of DNA. This study integrates the outstanding properties of carbon quantum dots (CQDs) with PLL to develop a novel gene delivery vehicle with a core-shell hybrid nanostructure. The CQD/PLL core-shell nanoparticles (NPs) were, therefore, synthesized in such a way that they had narrow size distribution and an average diameter under 10 nm, both of which were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Fourier transform infrared (FTIR) spectroscopy exhibited that... 

    Synthesis of poly-substituted thiophenes in the realm of sulfonylketenimines chemistry

    , Article Journal of Sulfur Chemistry ; Volume 41, Issue 2 , 2020 , Pages 146-153 Saeedi, S ; Sedaghat, A ; Nematpour, M ; Jahani, M ; Tabatabai, S. A ; Sharif University of Technology
    Taylor and Francis Ltd  2020
    Abstract
    An efficient synthesis of highly substituted thiophenes was developed by means of sulfonylketenimines in a multi-step reaction including heterocumulene system containing sulfur and nitro-alkanes with acidic α-hydrogen. The speed and ease of conducting this four-component reaction under mild conditions and using available materials makes it an ideal method to synthesize high purity substituted thiophenes with sulfonamide moiety. All structures synthesized are confirmed by the instrumental analysis (EI-MS, IR and 1H /13C-NMR). © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group  

    Comparison of adsorption process by GAC with novel formulation of coagulation - Flocculation for color removal of textile wastewater

    , Article International Journal of Environmental Research ; Volume 2, Issue 3 , 2008 , Pages 239-248 ; 17356865 (ISSN) Hassani, A. H ; Seif, S ; Javid, A. H ; Borghei, M ; Sharif University of Technology
    2008
    Abstract
    This study evaluates the effectiveness of adsorption process by Granular Activated Carbon (GAC) compared with a novel formulation of coagulation - flocculation process for dye removal from textile wastewater. In this regard, acidic, reactive, disperse and direct red dye are used to prepare the synthetic dye. Dominant wave length for each dye is determined by spectrophotometeric method. Using GAC as adsorbent, equilibrium time and adsorption isotherm of each dye are determined with aid of spectrophotometric method. The results show that GAC can not remove dispersed red dye. Acidic red, direct red and reactive red of 5 mg/L concentration are removed by GAC up to %90, %88 and %43 in 30, 60 and... 

    The effect of oxidation of macroporous silicon on carbon nanotubes growth by TCVD method

    , Article Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry ; Volume 37, Issue 6 , 2007 , Pages 489-492 ; 15533174 (ISSN) Mortazavi, S. Z ; Iraji zad, A ; Taghavi, N. S ; Reyhani, A ; Sharif University of Technology
    2007
    Abstract
    Carbon nanotubes (CNTs) were grown on deposited Ni on macroporous silicon by thermal chemical vapor deposition (TCVD) method using CH4 as the reaction gas. Macroporous silicon was fabricated by electrochemical etching of P-type silicon in organic electrolytes. The effect of oxidation of porous silicon (PS) on growth rate, morphology and structure of CNTs has been studied. The SEM micrographs and Raman spectra indicated that the nanotubes grown on the oxidized PS are more homogeneous and regular than those grown on the pristine PS and growth rate of CNTs grown on oxidized PS higher than those grown on pristine PS. In addition, the CNTs grown on the non-oxidized PS have different morphology... 

    Ultrathin carbon nanoparticle composite film electrodes: distinguishing dopamine and ascorbate

    , Article Electroanalysis ; Volume 19, Issue 10 , 2007 , Pages 1032-1038 ; 10400397 (ISSN) Amiri, M ; Shahrokhian, S ; Marken, F ; Sharif University of Technology
    2007
    Abstract
    Ultrathin carbon nanoparticle-poly(diallyldimethylammonium chloride) films (CNP-PDDAC films) are formed on tin-doped indium oxide (ITO) electrodes in a layer-by-layer electrostatic deposition process employing 9-18 nm diameter carbon particles. Transparent and strongly adhering films of high electrical conductivity are formed and characterized in terms of their electrochemical reactivity. When immersed in aqueous 0.1 M phosphate buffer pH 7, each layer of CNP-PDDAC (of ca. 5-6 nm average thickness) is adding an interfacial capacitance of ca. 10 μF cm-2. Absorption into the CNP-PDDAC nanocomposite film is dominated by the sites in the PDDAC cationomer and therefore anionic molecules such as... 

    Carbon nanotubes composite membrane for water desalination

    , Article Advances in Science, Technology and Innovation ; 2021 , Pages 163-184 ; 25228714 (ISSN) Taghipour, S ; Khadir, A ; Taghipour, M ; Sharif University of Technology
    Springer Nature  2021
    Abstract
    The demand for freshwater has enormously risen the water stress in various parts of the globe. Accessibility of clean water is crucial for sustainable development involving socioeconomic and environmental promotion. Considering the fact that 96.5% of all Earth’s water is related to seawater, desalination (producing clean potable water from sea or saline water) can be considered as a leading solution to fulfill water scarcity problem. Among various advanced and conventional techniques, carbon nanotube (CNT) membrane has become an attractive alternate for most of water treatment methods owing supreme features such as easy operationality, low energy and expense requirement, high water... 

    An efficient one-pot Michael addition of dithiocarbamate anion to α,β-unsaturated olefins mediated by lithium perchlorate

    , Article Journal of Sulfur Chemistry ; Volume 26, Issue 2 , 2005 , Pages 149-153 ; 17415993 (ISSN) Ziyaei-Halimjani, A ; Saidi, M. R ; Sharif University of Technology
    Taylor and Francis Ltd  2005
    Abstract
    The reaction of substituted dithiocarbamates with electrophilic alkenes in the presence of LiClO4 was investigated in an attempt to prepare numerous ethyl dithiocarbamates bearing β-electron-withdrawing-group substituents. The reaction conditions are mild, neutral, with extremely simple work-up procedures, and offer high yield. © 2005 Taylor & Francis Group Ltd  

    Microwave-assisted methylation of carboxylic acids and phenolic compounds with dimethyl-carbonate under solvent-free condition

    , Article Synthetic Communications ; Volume 34, Issue 22 , 2004 , Pages 4179-4188 ; 00397911 (ISSN) Rajabi, F ; Saidi, M. R ; Sharif University of Technology
    2004
    Abstract
    Phenolic compounds and carboxylic acids are methylated with dimethyl carbonate in the presence of a catalytic amount of BF3· OEt2, DBU, or KOH, in good to excellent yields under microwave irradiation and solvent-free conditions  

    Electrocatalytic oxidation of 2-thiouracil and 2-thiobarbituric acid at a carbon-paste electrode modified with cobalt phthalocyanine

    , Article Electroanalysis ; Volume 16, Issue 11 , 2004 , Pages 915-921 ; 10400397 (ISSN) Shahrokhian, S ; Hamzehloei, A ; Thaghani, A ; Mousavi, S. R ; Sharif University of Technology
    2004
    Abstract
    Voltammetric behavior of two mercaptopyrimidine derivatives (2-thiouracil and 2-thiobarbituric acid) has been studied by cyclic voltammetry at a cobalt phthalocyanine (CoPc)-modified carbon-paste electrode. The results of voltammetric determinations showed that the CoPc in the matrix of modified electrode acts as catalyst for electrooxidation of these thiols (RSH), lowering the overpotential of the reaction and significantly increasing the sensitivity for detection of thiols in neutral conditions. The results of voltammetric and polarization measurements in solutions with various pHs were used for prediction of the mechanism of electrocatalytic oxidation at the surface of modified electrode.... 

    Electrocatalytic oxidation of penicillamine at a carbon paste electrode modified with cobalt salophen

    , Article Journal of Electroanalytical Chemistry ; Volume 565, Issue 1 , 2004 , Pages 95-101 ; 15726657 (ISSN) Shahrokhian, S ; Souri, A ; Khajehsharifi, H ; Sharif University of Technology
    Elsevier  2004
    Abstract
    Electrocatalytic oxidation of penicillamine (PA) at a carbon paste electrode chemically modified with cobalt salophen as a schiff base complex (CoSal) was thoroughly investigated. The results of cyclic voltammetry (CV) and polarization studies were used for the prediction of the mechanism of electrochemical oxidation of PA mediated with CoSal at the surface of a modified electrode. The performance of the modified electrode was compared with those of electrodes modified with cobalt phthalocyanine (CoPc). In comparison, CoSal appears to be considerably more effective as a catalyst for reduction of the overpotential of the anodic oxidation of PA, resulting in a very sharp anodic CV peak at... 

    A study on austenite decomposition during continuous cooling of a low carbon steel

    , Article Materials and Design ; Volume 25, Issue 8 , 2004 , Pages 673-679 ; 02613069 (ISSN) Serajzadeh, S ; Karimi Taheri, A ; Sharif University of Technology
    Elsevier Ltd  2004
    Abstract
    In this work, a model based on the finite element method and assumption of second order phase transformation has been developed to predict temperature history and austenite decomposition kinetics during continuous cooling of a low carbon steel. In order to accurately assess the temperature field and transformation rate the effects of various factors such as work hardening role on the kinetics of transformation, interconnection between austenite phase change and thermo-physical properties of the steel, and initial austenite grain size have been considered in the model. To verify the results of the modelling, time-temperature histories during cooling of a low carbon steel has been determined... 

    Serrated flow during warm forming of low carbon steels

    , Article Materials Letters ; Volume 57, Issue 29 , 2003 , Pages 4515-4519 ; 0167577X (ISSN) Serajzadeh, S ; Sharif University of Technology
    2003
    Abstract
    In the present paper, employing compression experiments for three grades of low carbon steel, the effects of deformation condition and chemical composition on the occurrence of dynamic strain ageing are studied. Also, based on the achieved results, the flow behavior of steels under warm deformation conditions is predicted for the employed steels. The results show that both chromium and niobium postpone the happening of serrated flow and shifts the serrated flow region to lower temperatures in comparison with low carbon steel, while the activation energy for commencing dynamic strain ageing increases. © 2003 Elsevier Science B.V. All rights reserved