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    Phase diagram of the strongly correlated Kane-Mele-Hubbard model

    , Article Physical Review B - Condensed Matter and Materials Physics ; Volume 85, Issue 19 , 2012 ; 10980121 (ISSN) Vaezi, A ; Mashkoori, M ; Hosseini, M ; Sharif University of Technology
    2012
    Abstract
    The phase diagram of the strongly correlated Hubbard model with intrinsic spin-orbit coupling on the honeycomb lattice is explored here. We obtain the low-energy effective model describing the spin degree of freedom. The resulting model is then studied by the Schwinger boson and Schwinger fermion approaches. The Schwinger boson method elucidates the boundary between the spin liquid phase and the magnetically ordered phases, Neel order, and incommensurate Neel order. Increasing the strength of the spin-orbit coupling is shown to narrow the width of the spin liquid region. The Schwinger fermion approach sheds further light on the nature of the spin liquid phase. We obtained three different... 

    Monte Carlo simulation of Feynman-α and Rossi-α techniques for calculation of kinetic parameters of Tehran research reactor

    , Article Annals of Nuclear Energy ; Volume 38, Issue 10 , 2011 , Pages 2140-2145 ; 03064549 (ISSN) Hosseini, S. A ; Vosoughi, N ; Hosseini, M ; Sharif University of Technology
    Abstract
    Noise analysis techniques including Feynman-α (variance-to-mean) and Rossi-α (correlation) have been simulated by MCNP computer code to calculate the prompt neutron decay constant (α0), effective delayed neutron fraction (βeff) and neutron generation time (Λ) in a subcritical condition for the first operating core configuration of Tehran Research Reactor (TRR). The reactor core is considered to be in zero power (reactor power is less than 1 W) in the entire simulation process. The effect of some key parameters such as detector efficiency, detector position and its dead time on the results of simulation has been discussed as well. The results of proposed method in the current study are... 

    Mesoscale finite element prediction of concrete failure

    , Article Computational Materials Science ; Volume 50, Issue 7 , 2011 , Pages 1973-1990 ; 09270256 (ISSN) Shahbeyk, S ; Hosseini, M ; Yaghoobi, M ; Sharif University of Technology
    Abstract
    The present paper studies the failure of concrete from the mesoscopic point of view. Biphasic cubic concrete samples containing spherical aggregates embedded in a homogenized mortar have been simulated using standard finite element method. Linear elasticity and damage-plasticity hypotheses are considered for the aggregates and mortar, respectively. Various triaxial loading conditions are assumed for each sample to generate adequate discrete failure points within the stress space. In the next step, the approximated failure surfaces of specimens are constructed using the Delaunay triangulation technique. The effects of mesostructural features such as aggregate grading curve, aggregate... 

    Optimization of a/b-axis regions of YBCO thin film for sensor applications

    , Article Proceedings of the National Academy of Sciences India Section A - Physical Sciences ; Volume 88, Issue 4 , 2018 , Pages 625-628 ; 03698203 (ISSN) Foroughi Abari, F ; Hosseini, M ; Fardmanesh, M ; Sharif University of Technology
    Springer  2018
    Abstract
    The effect of substrate temperature on epitaxial growth of Y1Ba2Cu3O7−x film deposited on (100) crystalline lanthanum aluminate (LAO) substrates by RF Sputtering method has been investigated. The crystal mismatch between film and substrate is about 1.6%. The sputtering was carried out in vacuum with base pressure better than 10−5 Torr and 10/20 Pa oxygen/argon partial pressures. Substrate temperature at this condition is about 730 °C based on Bormann–Hammond diagram. As well known, because of the small lattice mismatch between YBCO and LAO, fabricated thin films are not perfectly c-axis and there is tendency to form a/b-axis regions in the film. Due to substantial effects of the density and... 

    The Effect of the Step Height on Energy Dissipation in Stepped Spillways Using Numerical Simulation

    , Article Arabian Journal for Science and Engineering ; Vol. 39, issue. 4 , 2014 , p. 2587-2594 Attarian, A ; Hosseini, K ; Abdi, H ; Hosseini, M ; Sharif University of Technology
    Abstract
    From 1970s, studies have been conducted on the hydraulic design of stepped spillways and many empirical formulas were developed. Despite the simple geometry of these spillways, their hydraulic behavior is complicated. As a result, for many cases, the physical models are studied to verify the design. Numerical simulation is considered as a tool to reduce the laboratory tests, in order to save time and money. Furthermore, the parameters which are not investigated or measured in physical models could be evaluated. In this paper, the results of numerical simulations are compared with the results of physical models and empirical formulas for the spillway of Renwick dam studied in a 1/8 scale... 

    An adaptive regression tree for non-stationary data streams

    , Article Proceedings of the ACM Symposium on Applied Computing ; March , 2013 , Pages 815-816 ; 9781450316569 (ISBN) Gholipour, A ; Hosseini, M. J ; Beigy, H ; Sharif University of Technology
    2013
    Abstract
    Data streams are endless flow of data produced in high speed, large size and usually non-stationary environments. The main property of these streams is the occurrence of concept drifts. Using decision trees is shown to be a powerful approach for accurate and fast learning of data streams. In this paper, we present an incremental regression tree that can predict the target variable of newly incoming instances. The tree is updated in the case of occurring concept drifts either by altering its structure or updating its embedded models. Experimental results show the effectiveness of our algorithm in speed and accuracy aspects in comparison to the best state-of-the-art methods  

    A novel method of flat YBCO rings development for shield-type superconducting fault current limiters fabrication

    , Article Physica C: Superconductivity and its Applications ; Volume 472, Issue 1 , January , 2012 , Pages 39-43 ; 09214534 (ISSN) Hekmati, A ; Hosseini, M ; Vakilian, M ; Fardmanesh, M ; Sharif University of Technology
    Abstract
    The application of flat superconductor rings has been investigated in the structure of inductive shield-type high temperature superconducting fault current limiters, HT c-SFCL. A laboratory scale inductive shield-type HT c-SFCL has been designed and fabricated using flat superconductor rings. The fabrication process has been fully presented. YBCO powder has been used for the fabrication of superconductor rings. This fabrication process, being quite innovative, is introduced completely. The method of the trapped field measurement has been used for the critical current density measurement of the fabricated superconductor rings. The device with nominal current of 2 A was tested in a 30 V... 

    Tunable bandgap opening in the proposed structure of silicon-doped graphene

    , Article Micro and Nano Letters ; Volume 6, Issue 8 , 2011 , Pages 582-585 ; 17500443 (ISSN) Azadeh, M. S. S ; Kokabi, A ; Hosseini, M ; Fardmanesh, M ; Sharif University of Technology
    2011
    Abstract
    A specific structure of doped graphene with substituted silicon impurity is introduced and ab initio density-functional approach is applied for the energy band structure calculation of the proposed structure. Using the band structure calculation for different silicon sites in the host graphene, the effect of silicon concentration and unit cell geometry on the bandgap of the proposed structure is also investigated. Chemically, silicon-doped graphene results in an energy gap as large as 2eV according to density-functional theory calculations. As the authors will show, in contrast to previous bandgap engineering methods, such structure has significant advantages including wide gap tuning... 

    Production of perovskite catalysts on ceramic monoliths with nanoparticles for dual fuel system automobiles

    , Article International Journal of Environmental Science and Technology ; Volume 6, Issue 1 , 2009 , Pages 105-112 ; 17351472 (ISSN) Khanfekr, A ; Arzani, K ; Nemati, A ; Hosseini, M ; Sharif University of Technology
    CEERS  2009
    Abstract
    (Lanthanum, Cerium)(Iron, Manganese, Cobalt, Palladium)(Oxygen)3- Perovskite catalyst was prepared by the citrate route and deposited on ceramic monoliths via dip coating procedure. The catalyst was applied on a car with XU7 motors and the amount of emission was monitored with vehicle emission test systems in Sapco company. The results were compared with the imported catalyst with noble metals such as palladium, platinum and rhodium by Iran Khodro company based on the Euro III standards. The catalysts were characterized by specific surface area measurements, scanning electron microscopy, X-ray diffraction, line scan and map. In the results, obtained in the home made sample, the amount of... 

    Pull-in behavior of functionally graded micro/nano-beams for MEMS and NEMS switches

    , Article Microsystem Technologies ; 2018 ; 09467076 (ISSN) Haghshenas Gorgani, H ; Mahdavi Adeli, M ; Hosseini, M ; Sharif University of Technology
    Springer Verlag  2018
    Abstract
    In this paper, pull-in behavior of cantilever micro/nano-beams made of functionally graded materials (FGM) with small-scale effects under electrostatic force is investigated. Consistent couple stress theory is employed to study the influence of small-scale on pull-in behavior. According to this theory, the couple tensor is skew-symmetric by adopting the skew-symmetric part of the rotation gradients. The material properties except Poisson’s ratio obey the power law distribution in the thickness direction. The approximate analytical solutions for the pull-in voltage and pull-in displacement of the microbeams are derived using the Rayleigh–Ritz method. Comparison between the results of the... 

    Manganese(III) porphyrin anchored onto magnetic nanoparticles via “Click” reaction: An efficient and reusable catalyst for the heterogeneous oxidation of alkenes and sulfides

    , Article Inorganic Chemistry Communications ; Volume 107 , 2019 ; 13877003 (ISSN) Bagherzadeh, M ; Hosseini, M ; Mortazavi Manesh, A ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Oxidation of a variety of organic compounds, using Mn-porphyrin, mesotetrakis(4-hydroxyphenyl)porphyrinatomanganese(III), supported onto functionalized silica-coated magnetic nanoparticles via “Click” reaction has been investigated. The heterogeneous catalyst was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP/OES) and energy-dispersive X-ray spectroscopy (EDX). Thermogravimetric analysis (TGA) demonstrated that the prepared catalyst was thermally stable to almost 300 °C, exhibiting high thermostability of the nanocatalyst over a broad range of temperatures. This... 

    Pull-in behavior of functionally graded micro/nano-beams for MEMS and NEMS switches

    , Article Microsystem Technologies ; Volume 25, Issue 8 , 2019 , Pages 3165-3173 ; 09467076 (ISSN) Haghshenas Gorgani, H ; Mahdavi Adeli, M ; Hosseini, M ; Sharif University of Technology
    Springer Verlag  2019
    Abstract
    In this paper, pull-in behavior of cantilever micro/nano-beams made of functionally graded materials (FGM) with small-scale effects under electrostatic force is investigated. Consistent couple stress theory is employed to study the influence of small-scale on pull-in behavior. According to this theory, the couple tensor is skew-symmetric by adopting the skew-symmetric part of the rotation gradients. The material properties except Poisson’s ratio obey the power law distribution in the thickness direction. The approximate analytical solutions for the pull-in voltage and pull-in displacement of the microbeams are derived using the Rayleigh–Ritz method. Comparison between the results of the... 

    Intermolecular C-H⋯O and n → π∗ and short intramolecular σ → π∗ interactions in the molybdenum(0) tetracarbonyl complex of a very twisted 14-membered tetraazaannulene macrocyclic ligand: Structural and computational studies

    , Article CrystEngComm ; Volume 21, Issue 35 , 2019 , Pages 5222-5226 ; 14668033 (ISSN) Kia, R ; Hosseini, M ; Abdolrahimi, A ; Mahmoudi, M ; Sharif University of Technology
    Royal Society of Chemistry  2019
    Abstract
    The structural and computational studies of a new molybdenum tetracarbonyl complex of 5,14-dihydro-6,17-dimethyl-8,15-diphenyldibenzo[b,i]-[1,4,8,11]tetraazacyclotetradecine, a 14-membered tetraazaannulene macrocyclic ligand, Me2Ph2H2TAA, were carried out by X-ray crystallography and density functional and natural bond orbital (NBO) theories. The complex showed an interesting intermolecular C-H⋯O hydrogen bond which was supported by n → π∗ interaction, forming a one-dimensional extended chain along the b-axis. Interesting intramolecular C-H⋯π and very short σ → π∗ (C-H⋯CO) interactions stabilized the twisted geometry of the coordinated ligand. © 2019 The Royal Society of Chemistry 2019  

    Intermolecular C-H⋯O and n → π∗ and short intramolecular σ → π∗ interactions in the molybdenum(0) tetracarbonyl complex of a very twisted 14-membered tetraazaannulene macrocyclic ligand: Structural and computational studies

    , Article CrystEngComm ; Volume 21, Issue 35 , 2019 , Pages 5222-5226 ; 14668033 (ISSN) Kia, R ; Hosseini, M ; Abdolrahimi, A ; Mahmoudi, M ; Sharif University of Technology
    Royal Society of Chemistry  2019
    Abstract
    The structural and computational studies of a new molybdenum tetracarbonyl complex of 5,14-dihydro-6,17-dimethyl-8,15-diphenyldibenzo[b,i]-[1,4,8,11]tetraazacyclotetradecine, a 14-membered tetraazaannulene macrocyclic ligand, Me2Ph2H2TAA, were carried out by X-ray crystallography and density functional and natural bond orbital (NBO) theories. The complex showed an interesting intermolecular C-H⋯O hydrogen bond which was supported by n → π∗ interaction, forming a one-dimensional extended chain along the b-axis. Interesting intramolecular C-H⋯π and very short σ → π∗ (C-H⋯CO) interactions stabilized the twisted geometry of the coordinated ligand. © 2019 The Royal Society of Chemistry 2019  

    Evaluation of test collection construction methods: A case study

    , Article 2008 International Conference on Information and Knowledge Engineering, IKE 2008, Las Vegas, NV, 14 July 2008 through 17 July 2008 ; January , 2008 , Pages 16-22 ; 1601320752 (ISBN); 9781601320759 (ISBN) Sheykh Esmaili, K ; Hosseini, M ; Rostami, A ; Abolhassani, H ; Sharif University of Technology
    2008
    Abstract
    Currently there is no standard test collection for evaluation of Farsi information retrieval systems. In this paper we introduce Mahak, the first complete test collection generally available for evaluating Farsi information retrieval systems. In addition, we have used different methods for constructing Mahak qrels and we have compared performance of these methods  

    Modeling superconductive fault current limiter using constructive neural networks

    , Article 2007 IEEE International Symposium on Industrial Electronics, ISIE 2007, Caixanova - Vigo, 4 June 2007 through 7 June 2007 ; 2007 , Pages 2859-2863 ; 1424407559 (ISBN); 9781424407552 (ISBN) Makki, B ; Sadati, N ; Hosseini, M. N ; Sharif University of Technology
    2007
    Abstract
    Although so many advances have been proposed in the field of artificial intelligence and superconductivity, there are few reports on their combination. On the other hand, because of the nonlinear and multivariable characteristics of the superconductive elements and capabilities of neural networks in this field, it seems useful to apply the neural networks to model and control the superconductive phenomena or devices. In this paper, a new constructive neural network (CNN) trained by two different optimization algorithms; back-propagation and genetic algorithm, is proposed which models the behavior of the superconductive fault current limiters (SFCLs). Simulation results show that the proposed... 

    Modeling of Series Static Voltage Restorer (SSVR) in distribution systems load flow

    , Article 2007 Large Engineering Systems Conference on Power Engineering, LESCOPE'07, Montreal, QC, 10 October 2007 through 12 October 2007 ; January , 2007 , Pages 310-315 ; 9781424415830 (ISBN) Fotuhi Firuzabad, M ; Shayanfar, H. A ; Hosseini, M ; Sharif University of Technology
    2007
    Abstract
    This paper presents modeling of Series Static Voltage Restorer (SSVR) in load flow calculations for steadystate voltage compensation. An accurate model for SSVR is derived to use in load flow calculations. The rating of this device as well as direction of required reactive power injection to compensate voltage to the desired value (1p.u.) is derived and discussed analytically and mathematically using pahsor diagram method. Since performance of SSVR varies when it reaches to its maximum capacity, modeling of SSVR in its maximum rating of reactive power injection is derived. The validity of the proposed model is examined using two standard distribution systems consisting of 33 and 69 nodes,... 

    An incompressible SPH method for simulation of unsteady viscoelastic free-surface flows

    , Article International Journal of Non-Linear Mechanics ; Volume 42, Issue 10 , 2007 , Pages 1210-1223 ; 00207462 (ISSN) Rafiee, A ; Manzari, M. T ; Hosseini, M ; Sharif University of Technology
    2007
    Abstract
    In this paper, an incompressible smoothed particle hydrodynamics (SPH) method is presented to solve unsteady free-surface flows. Both Newtonian and viscoelastic fluids are considered. In the case of viscoelastic fluids, both the Maxwell and Oldroyd-B models are investigated. The proposed SPH method uses a Poisson pressure equation to satisfy the incompressibility constraints. The solution algorithm is an explicit predictor-corrector scheme and employs an adaptive smoothing length based on density variations. To alleviate the numerical difficulties encountered when fluid is highly stretched, an artificial stress term is incorporated into the momentum equation which reduces the risk of... 

    Efficient seismic risk assessment of irregular steel-framed buildings through endurance time analysis of consistent fish-bone model

    , Article Structural Design of Tall and Special Buildings ; 2021 ; 15417794 (ISSN) Ahmadie Amiri, H ; Hosseini, M ; E. Estekanchi, H ; Sharif University of Technology
    John Wiley and Sons Ltd  2021
    Abstract
    The seismic risk framework of building structures has been presented to reduce earthquake-induced adverse consequences. In this context, probabilistic analysis of engineering demand parameters (EDPs) is always associated with many uncertainties and high computational demand for use in practical applications. This study has been presented to efficiently estimate the distribution of EDPs in probabilistic seismic risk assessment of irregular steel moment-resisting frames (SMRFs). For this purpose, the incorporation of the consistent fish-bone (CFB) model and the endurance time (ET) analysis method has been used. The proposed method (i.e., CFB-ET) has a substantial impact on reducing the... 

    Efficient seismic risk assessment of irregular steel-framed buildings through endurance time analysis of consistent fish-bone model

    , Article Structural Design of Tall and Special Buildings ; 2021 ; 15417794 (ISSN) Ahmadie Amiri, H ; Hosseini, M ; E. Estekanchi, H ; Sharif University of Technology
    John Wiley and Sons Ltd  2021
    Abstract
    The seismic risk framework of building structures has been presented to reduce earthquake-induced adverse consequences. In this context, probabilistic analysis of engineering demand parameters (EDPs) is always associated with many uncertainties and high computational demand for use in practical applications. This study has been presented to efficiently estimate the distribution of EDPs in probabilistic seismic risk assessment of irregular steel moment-resisting frames (SMRFs). For this purpose, the incorporation of the consistent fish-bone (CFB) model and the endurance time (ET) analysis method has been used. The proposed method (i.e., CFB-ET) has a substantial impact on reducing the...