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    Preparation of Titania based solid strong acid and study of its catalytic activity in esterification of Phthalic anhydride and Sebacic acid

    , Article Materials Letters ; Volume 60, Issue 6 , 2006 , Pages 715-719 ; 0167577X (ISSN) Khodadadi Moghaddam, M ; Gholami, M. R ; Sharif University of Technology
    2006
    Abstract
    Esterification of Phthalic anhydride with 2-Octanol and Sebacic acid with Ethanol has been studied in the presence of Sulfated Titania. This study showed that Sulfated Titania has strong catalytic effect on esterification reactions. The effect of some factors such as reaction temperature, molar ratio of acid to alcohol, amount of catalyst used, reaction time, calcination temperature, drying temperature and calcination atmosphere has been investigated. Equilibrium composition achieved in 80 min for Diethyl Sebacate and 20 min for Dioctyl Phthalate in various conditions. © 2005 Elsevier B.V. All rights reserved  

    Solvatochromic parameters for binary mixtures of an ionic liquid with various protic molecular solvents

    , Article Monatshefte fur Chemie ; Volume 140, Issue 3 , 2009 , Pages 329-334 ; 00269247 (ISSN) Khodadadi Moghaddam, M ; Habibi Yangjeh, A ; Gholami, M. R ; Sharif University of Technology
    2009
    Abstract
    Solvatochromic parameters (E T N , normalized polarity parameter; π, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen-bond donor acidity) have been determined for binary mixtures of propan-2-ol, propan-1-ol, ethanol, methanol and water with recently synthesized ionic liquid (IL; 2-hydroxyethylammonium formate) at 25 °C. In all solutions except aqueous solution, E T N values of the media increase abruptly with the ILs mole fraction and then increase gradually to the value of pure IL. A synergistic behavior is observed for the α parameter in all solutions. The behavior of π and β are nearly ideal for all solutions except for solutions of methanol with the IL. The... 

    Solvent effects on the reaction rate and selectivity of synchronous heterogeneous hydrogenation of cyclohexene and acetone in ionic liquid/alcohols mixtures

    , Article Journal of Molecular Catalysis A: Chemical ; Volume 306, Issue 1-2 , 2009 , Pages 11-16 ; 13811169 (ISSN) Khodadadi Moghaddam, M ; Habibi Yangjeh, A ; Gholami, M. R ; Sharif University of Technology
    2009
    Abstract
    Synchronous heterogeneous catalytic hydrogenation of cyclohexene and acetone, catalyzed by Pt/Al2O3, was carried out in solutions of 2-hydroxy ethylammonium formate (a room temperature ionic liquid, RTIL) with ethanol and propan-1-ol at 25 °C. Rate constants and selectivity of the reaction (relative to cyclohexene hydrogenation) increase with mole fraction of the ionic liquid (IL). The reactants tendency to the catalyst surface increases by addition of the ionic liquid and thus the reaction rate increases, especially for cyclohexene hydrogenation. Consequently the selectivity to cyclohexene hydrogenation was increased. Single-parameter correlations of log k vs. π* (dipolarity/polarizibility)... 

    Kinetic study of heterogeneous catalytic hydrogenation of cyclohexene to cyclohexane in ionic liquid-alcohols mixtures

    , Article Applied Catalysis A: General ; Volume 341, Issue 1-2 , 2008 , Pages 58-64 ; 0926860X (ISSN) Khodadadi Moghaddam, M ; Habibi Yangjeh, A ; Gholami, M. R ; Sharif University of Technology
    2008
    Abstract
    Heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by Pt/Al2O3, was carried out in solutions of 2-hydroxyethylammonium formate (a room temperature ionic liquid, RTIL) mixed with methanol, ethanol and propan-2-ol at 25 °C. The rate constants of the reaction in ionic liquid alcohol mixtures were higher than alcohol alone. First-order rate constant of the reaction in the RTIL relative to propan-2-ol is approximately 28. Furthermore, the rate constant of the reaction increases with the mole fraction of the ionic liquid. Single-parameter correlations of log k vs. normalized polarity parameter (ETN), hydrogen-bond acceptor basicity (β) and hydrogen-bond donor acidity (α) do not give... 

    Solvent effects on the reaction rate and selectivity of synchronous heterogeneous hydrogenation of cyclohexene and acetone in ionic liquid/alcohols mixtures

    , Article Journal of Molecular Catalysis A: Chemical ; Volume 306, Issues 1–2 , July , 2009 , Pages 11–16 Khodadadi-Moghaddam, M. (Mohammad) ; Habibi-Yangjeh, A. (Aziz) ; Gholamia, M. R. (Mohamad Reza) ; Sharif University of Tecnology
    2009
    Abstract
    Synchronous heterogeneous catalytic hydrogenation of cyclohexene and acetone, catalyzed by Pt/Al2O3, was carried out in solutions of 2-hydroxy ethylammonium formate (a room temperature ionic liquid, RTIL) with ethanol and propan-1-ol at 25 °C. Rate constants and selectivity of the reaction (relative to cyclohexene hydrogenation) increase with mole fraction of the ionic liquid (IL). The reactants tendency to the catalyst surface increases by addition of the ionic liquid and thus the reaction rate increases, especially for cyclohexene hydrogenation. Consequently the selectivity to cyclohexene hydrogenation was increased. Single-parameter correlations of log kvs.π* (dipolarity/polarizibility)... 

    The synthesis of multiphasic ionic liquid-coated Pt/Al2O3 catalysts: the selective synchronous hydrogenation of C=C and C=O bonds and the modeling of the ionic liquid and solvent effects

    , Article Catalysis Science & Technology ; Issue 2, 2014 , Oct , 2013 , pages 447-455 Vatan Meidanshahi, R. (Reza) ; Tasviri, M. (Mahboubeh) ; Khodadadi-moghaddam, M. (Mohammad) ; Gholami, M. R. (Mohammad Reza) ; Sharif University of Technology
    2013
    Abstract
    Various ionic liquids (ILs) and their mixtures were coated on the Pt/Al2O3 catalyst and the resulting IL-coated catalysts were used in the synchronous hydrogenation of cyclohexene and acetone. The rate constant (k) and selectivity (S) toward CO hydrogenation were determined for several catalysts in various solvents. The solvatochromic parameters (ETN, normalized polarity parameter; π*, dipolarity-polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen-bond donor acidity) were determined for the used ILs and solvents and the obtained selectivities were modeled based on the solvatochromic parameters of the IL layer and bulk solvent while using the Multiparameter Linear Regression (MLR)... 

    Preferential solvation and behavior of solvatochromic indicators in mixtures of an ionic liquid with some molecular solvents

    , Article The Journal of Physical Chemistry B ; vol.114 (29) , July , 2010 , pp 9586–9593 Salari, H. (Hadi) ; Khodadadi-Moghaddam, M.(Mohammad) ; Harifi-Mood, A. R. (Ali Reza) ; Gholami, M. R. (Mohammad Reza) ; Sharif University of Technology
    2010
    Abstract
    Structural and intermolecular interactions of solvatochromic probes 4-nitroaniline, 4-nitroanisole, and Reichardt’s dye were investigated in the binary mixtures of 2-hydroxy ethylammonium formate as an ionic liquid with N,N-dimethyl formamide, dimethyl amine, and dimethyl sulfoxide. Solvatochromic parameters (ETN, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen -bond donor acidity) were determined in ionic liquid mixtures at 25 °C using UV−vis spectroscopy. ETN parameters obtained from absorbance of Reichardt’s dye within various mixtures of ionic liquid were observed to be higher than predicted values from ideal additive... 

    The ion streaming effect on weibel instability in the relativistic dense plasma

    , Article Contributions to Plasma Physics ; Volume 57, Issue 8 , 2017 , Pages 351-356 ; 08631042 (ISSN) Khodadadi Azadboni, F ; Mahdavi, M ; Sharif University of Technology
    2017
    Abstract
    The Weibel instability plays an important role in stopping hot electrons and energy deposition mechanism in fast ignition of inertial fusion process. In this paper, the ion Weibel instability in counter propagating electron-ion plasmas is investigate. The obtained results show that the growth rate of Weibel instability will be decreased about 40% with the anisotropy velocity as vxe = 2vze = 20; the ion density ratio, b = n0i1/n0i2, and density gradient, are increasing 50 and 90% respectively. The ion streaming in density gradient of dense plasma leads to increasing the Weibel instability growth rate and its amplification through ion streaming in the large wavenumber. The maximum unstable... 

    Kinetic Study of Heterogeneous and Homogeneous Catalytic Reactions in Molecular and Ionic Solvents and Their Mixtures

    , Ph.D. Dissertation Sharif University of Technology Khodadadi Moghaddam, Mohammad (Author) ; Gholami, Mohammad Reza (Supervisor) ; Habibi Yangjeh, Aziz (Supervisor)
    Abstract
    Solvatochromic parameters (ETN: normalized polarity parameter, π*: dipolarity/polarizability, β: hydrogen-bond acceptor basicity, α: hydrogen-bond donor acidity) have been determined for binary mixtures of propan-2-ol, propan-1-ol, ethanol, methanol and water with recently synthesized ionic liquid (2-hydroxyethylammonium formate) at 25 ◦C. The applicability of nearly ideal combined binary solvent/Redlich-Kister equation was proved for the correlation of various solvatochromic parameters with solvent composition. Solute-solvent and solvent-solvent interactions were applied to interpret the results. Heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by Pt/Al2O3, was carried out in... 

    Acidic derivatives of melamine as template in copolymerization of aniline and metanilic acid

    , Article Polymer - Plastics Technology and Engineering ; 2017 , Pages 1-10 ; 03602559 (ISSN) Khodadadi, F ; Najafi Moghadam, P ; Hashemi, M. M ; Sharif University of Technology
    2017
    Abstract
    In this paper, new polymer composites were synthesized by template copolymerization of aniline and metanilic acid in the presence of prepared melamine triacetic acid and poly(melamine-co-citric acid) as polyacids and dopants. The properties of the poly(aniline-co-metanilic acid) composites were studied by Fourier transform infrared, X-ray diffraction, scanning electron microscope, CV, and differential scanning calorimeter analysis. The four-point probe technique was used for evaluating the electrical conductivity of the composites. The scanning electron micrographs disclosed that the products had the morphology with agglomerated distorted spherical shapes with the average size of 40–50 nm.... 

    Acidic derivatives of melamine as template in copolymerization of aniline and metanilic acid

    , Article Polymer - Plastics Technology and Engineering ; Volume 57, Issue 10 , 2018 , Pages 965-974 ; 03602559 (ISSN) Khodadadi, F ; Najafi Moghadam, P ; Hashemi, M. M ; Sharif University of Technology
    Taylor and Francis Inc  2018
    Abstract
    In this paper, new polymer composites were synthesized by template copolymerization of aniline and metanilic acid in the presence of prepared melamine triacetic acid and poly(melamine-co-citric acid) as polyacids and dopants. The properties of the poly(aniline-co-metanilic acid) composites were studied by Fourier transform infrared, X-ray diffraction, scanning electron microscope, CV, and differential scanning calorimeter analysis. The four-point probe technique was used for evaluating the electrical conductivity of the composites. The scanning electron micrographs disclosed that the products had the morphology with agglomerated distorted spherical shapes with the average size of 40–50 nm.... 

    Stock market index prediction using artificial neural network

    , Article Journal of Economics, Finance and Administrative Science ; Volume 21, Issue 41 , 2016 , Pages 89-93 ; 20771886 (ISSN) Hedayati Moghaddam, A ; Hedayati Moghaddam, M ; Esfandyari, M ; Sharif University of Technology
    Elsevier Doyma  2016
    Abstract
    In this study the ability of artificial neural network (ANN) in forecasting the daily NASDAQ stock exchange rate was investigated. Several feed forward ANNs that were trained by the back propagation algorithm have been assessed. The methodology used in this study considered the short-term historical stock prices as well as the day of week as inputs. Daily stock exchange rates of NASDAQ from January 28, 2015 to 18 June, 2015 are used to develop a robust model. First 70 days (January 28 to March 7) are selected as training dataset and the last 29 days are used for testing the model prediction ability. Networks for NASDAQ index prediction for two type of input dataset (four prior days and nine... 

    Effects of insulated and isothermal baffles on pseudosteady-state natural convection inside spherical containers

    , Article Journal of Heat Transfer ; Volume 132, Issue 6 , April , 2010 , Pages 1-10 ; 00221481 (ISSN) Duan, Y ; Hosseinizadeh, S. F ; Khodadadi, J. M ; Sharif University of Technology
    2010
    Abstract
    The effects of insulated and isothermal thin baffles on pseudosteady-state natural convection within spherical containers were studied computationally. The computations are based on an iterative, finite-volume numerical procedure using primitive dependent variables. Natural convection effect is modeled via the Boussinesq approximation. Parametric studies were performed for a Prandtl number of 0.7. For Rayleigh numbers of 104, 105, 106, and 107, baffles with three lengths positioned at five different locations were investigated (120 cases). The fluid that is heated adjacent to the sphere rises replacing the colder fluid, which sinks downward through the stratified stable thermal layer. For... 

    Synthesis of Conductive Magnetite Nanocomposite based on Polyaniline/Poly(maleic acid-co-acrylic acid) with Core-Shell Structure

    , Article Advances in Polymer Technology ; 2016 ; 07306679 (ISSN) Khodadadi, F ; Najafi Moghadam, P ; Mahmoodi Hashemi, M ; Sharif University of Technology
    John Wiley and Sons Inc  2016
    Abstract
    In this study, a new type of magnetite nanocomposite with a core-shell structure was synthesized using Fe3O4 nanoparticles as a core and polyaniline (PANI) as a shell. For this propose, the surface of Fe3O4 was chemically modified with hexamethylenediisocyanate (HMDI) to improve its compatibility and interphase interaction with the polymeric matrix. Thereafter, the PANI was reacted with modified Fe3O4 to anchor them to PANI by covalent bands which acted as a shell. In the second step, the poly (maleic acid-co-acrylic acid) (P(MAc-co-AA)) as polymeric dopant for the PANI was synthesized. Finally, the PANI anchored to Fe3O4 was immersed in an aqueous solution of poly (maleic... 

    Synthesis of conductive magnetite nanocomposite based on polyaniline/poly(maleic acid-co-acrylic acid) with core–shell structure

    , Article Advances in Polymer Technology ; Volume 37, Issue 4 , 2018 , Pages 1041-1049 ; 07306679 (ISSN) Khodadadi, F ; Najafi moghadam, P ; Mahmoodi hashemi, M ; Sharif University of Technology
    John Wiley and Sons Inc  2018
    Abstract
    In this study, a new type of magnetite nanocomposite with a core–shell structure was synthesized using Fe3O4 nanoparticles as a core and polyaniline (PANI) as a shell. For this propose, the surface of Fe3O4 was chemically modified with hexamethylenediisocyanate (HMDI) to improve its compatibility and interphase interaction with the polymeric matrix. Thereafter, the PANI was reacted with modified Fe3O4 to anchor them to PANI by covalent bands which acted as a shell. In the second step, the poly (maleic acid-co-acrylic acid) (P(MAc-co-AA)) as polymeric dopant for the PANI was synthesized. Finally, the PANI anchored to Fe3O4 was immersed in an aqueous solution of poly (maleic... 

    Effects of sucrose, skim milk and yeast powder on survival of lactobacillus rhamnosus gg encapsulated with alginate during one-week storage at room conditions

    , Article Applied Food Biotechnology ; Volume 9, Issue 3 , 2022 , Pages 251-259 ; 23455357 (ISSN) Khodadadi, P ; Tabandeh, F ; Alemzadeh, I ; Soltani, M ; Sharif University of Technology
    National Nutrition and Food Technology Research Institute  2022
    Abstract
    Background and Objective: During the manufacture and storage of probiotic products, there are always possibilities that probiotics be exposed to harmful stresses such as high temperature, low pH, various osmotic pressures and high oxygen levels, which can decrease the number of living cells. Encapsulation is one of the methods used to protect living cells such as probiotic bacteria from environmental challenges. Up-to-date, various compounds with abilities to protect bacteria during freeze-drying and to increase viability during storage have been identified. In this study, alginate with calcium chloride was used to encapsulate probiotic bacteria using extrusion method. Then, effects of... 

    Designing instrumented walker to measure upper-extremity’s efforts: a case study

    , Article Assistive Technology ; 2018 , Pages 1-9 ; 10400435 (ISSN) Khodadadi, M ; Arab Baniasad, M ; Arazpour, M ; Farahmand, F ; Zohoor, H ; Sharif University of Technology
    Taylor and Francis Inc  2018
    Abstract
    The high prevalence of shoulder pain in using walkers in patients who have spinal cord injury (SCI). Also, the limited options available to economically measure grip forces in walkers, which drove the need to create one. This article describes a method to obtain upper-extremities’ forces and moments in a person with SCI by designing an appropriate instrumented walker. First, since the commercial multidirectional loadcells are too expensive, custom loadcells are fabricated. Ultimately, a complete gait analysis by means of VICON motion analysis and using inverse dynamic method has been held to measure upper-extremities’ efforts. The results for a person with SCI using a two-wheel walker in low... 

    Designing instrumented walker to measure upper-extremity’s efforts: A case study

    , Article Assistive Technology ; Volume 31, Issue 5 , 2019 , Pages 267-275 ; 10400435 (ISSN) Khodadadi, M ; Baniasad, M. A ; Arazpour, M ; Farahmand, F ; Zohoor, H ; Sharif University of Technology
    Taylor and Francis Inc  2019
    Abstract
    The high prevalence of shoulder pain in using walkers in patients who have spinal cord injury (SCI). Also, the limited options available to economically measure grip forces in walkers, which drove the need to create one. This article describes a method to obtain upper-extremities’ forces and moments in a person with SCI by designing an appropriate instrumented walker. First, since the commercial multidirectional loadcells are too expensive, custom loadcells are fabricated. Ultimately, a complete gait analysis by means of VICON motion analysis and using inverse dynamic method has been held to measure upper-extremities’ efforts. The results for a person with SCI using a two-wheel walker in low... 

    A novel adaptive LMS-based algorithm considering relative velocity of source

    , Article 2010 7th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2010, 21 July 2010 through 23 July 2010, Newcastle upon Tyne ; 2010 , Pages 10-14 ; 9781861353696 (ISBN) Shirvani Moghaddam, S ; Shirvani Moghaddam, M ; Kalami Rad, R ; Sharif University of Technology
    2010
    Abstract
    In this paper a new least mean square (LMS) based adaptive weighting algorithm is proposed. It is appropriate for antenna array systems with moving targets and mobile applications. The essential goal of this algorithm is to reduce the complexity of weighting process and to decrease the time needed for adjusting the antenna radiation pattern. The main lobe of antenna will be adjusted in the direction of desired signal (main signal) and nulls pointed in the direction of undesired signals (interference signals). By predicting the relative velocity of source, the next location of the source will be estimated and the array weights will be determined using LMS algorithm before arriving to the new... 

    CMA-based adaptive antenna array digital beamforming with reduced complexity

    , Article 2010 7th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2010, 21 July 2010 through 23 July 2010, Newcastle upon Tyne ; 2010 , Pages 327-331 ; 9781861353696 (ISBN) Shirvani Moghaddam, S ; Shirvani Moghaddam, M ; Kalami Rad, R ; Sharif University of Technology
    2010
    Abstract
    Reducing the computational complexity as well as convergence time is the main task of adaptive antenna array processing. This article proposes an improved algorithm for estimating the weights of adaptive array elements based on Constant Modulus Algorithm (CMA). In this new type of algorithm, those weights that have higher effect on the radiation pattern will be estimated and antenna pattern will be adjusted by changing these weights. In this research, 3 new algorithms are proposed. By simulating these algorithms and comparing them with conventional full weight CMA, finally new algorithm that has a reduced complexity and an acceptable performance at different signal to noise ratios (SNRs) is...