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    Mixed branes at angle in compact spacetime

    , Article Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics ; Volume 475, Issue 1-2 , 2000 , Pages 39-45 ; 03702693 (ISSN) Arfaei, H ; Kamani, D ; Sharif University of Technology
    2000
    Abstract
    In this article the interaction of branes at angles with respect to each other with non-zero internal gauge fields are calculated by construction of the boundary states in spacetime in which some of its directions are compact on tori. The interaction depends on both angle and fields. (C) 2000 Elsevier Science B.V  

    Investigation of intense femto-second laser ionization and dissociation of methane with time-dependent density-functional approach

    , Article Chemical Physics Letters ; Vol. 604 , 2014 , Pages 60-67 ; ISSN: 00092614 Irani, E ; Sadighi Bonabi, R ; Anvari, A ; Sharif University of Technology
    Abstract
    Three dimensional calculations of electronic dynamics of CH4 in a strong laser field are presented with time-dependent density-functional theory. Time evolution of dipole moment and electron localization function is presented. The dependence of dissociation rate on the laser characters is shown and optimal effective parameters are evaluated. The optimum field leads to 76% dissociation probability for Gaussian envelope and 40 fs (FWHM) at 10 16 W cm-2. The dissociation probability is calculated by optimum convolution of dual short pulses. By combining of field assisted dissociation process and Ehrenfest molecular dynamics, time variation of bond length, velocity and orientation effect are... 

    Selective photo-dissociative ionization of methane molecule with TDDFT study

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 171 , 2017 , Pages 325-329 ; 13861425 (ISSN) Irani, E ; Anvari, A ; Sadighi Bonabi, R ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    Three dimensional calculation of control dynamics for finding the optimized laser filed is formulated using an iterative method and time-dependent density functional approach. An appropriate laser pulse is designed to control the desired products in the dissociation of methane molecule. The tailored laser pulse profile, eigenstate distributions and evolution of the efficient occupation numbers are predicted and exact energy levels of this five-atomic molecule is obtained. Dissociation rates of up to 78%, 80%, 90%, and 82% for CH2 +, CH+, C+ and C++ are achieved. Based on the present approach one can reduce the controlling costs. © 2016 Elsevier B.V  

    Simulation of red blood cell motion in microvessels using modified moving particle semi-implicit method

    , Article Scientia Iranica ; Volume 19, Issue 1 , 2012 , Pages 113-118 ; 10263098 (ISSN) Ahmadian, M. T ; Firoozbakhsh, K ; Hasanian, M ; Sharif University of Technology
    Abstract
    Red Blood Cells (RBCs) are the main cells in human blood, with a main role in the mechanical properties of blood as a fluid. Several methods have been improved to simulate the mechanical behavior of RBC in micro-capillaries. Since, in microscopic scales, using discrete models is more preferred than continuum methods, the Moving Particle Semi-Implicit method (MPS), which is a recent innovative particle based method, can simulate micro-fluidic flows based on NavierStokes equations. Although, by recent developments, the MPS method has turned into a considerable tool for modeling blood flow in micro meter dimensions, some problems, such as a commitment to use small time step sizes, still... 

    Controlling the multi-electron dynamics in the high harmonic spectrum from N2O molecule using TDDFT

    , Article Journal of Chemical Physics ; Volume 148, Issue 23 , 2018 ; 00219606 (ISSN) Monfared, M ; Irani, E ; Sadighi Bonabi, R ; Sharif University of Technology
    American Institute of Physics Inc  2018
    Abstract
    In this study, high harmonic generation from a multi-atomic nitrous oxide molecule was investigated. A comprehensive three-dimensional calculation of the molecular dynamics and electron trajectories through an accurate time-dependent density functional theory was conducted to efficiently explore a broad harmonic plateau. The effects of multi-electron and inner orbitals on the harmonic spectrum and generated coherent attosecond pulses were analyzed. The role of the valence electrons in controlling the process and extending the harmonic plateau was investigated. The main issue of producing a super-continuum harmonic spectrum via a frequency shift was considered. The time-frequency... 

    Analysis and characterization of phase evolution of nanosized BaTiO 3 powder synthesized through a chemically modified sol-gel process

    , Article Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science ; Volume 43, Issue 11 , November , 2012 , Pages 4414-4426 ; 10735623 (ISSN) Ashiri, R ; Sharif University of Technology
    2012
    Abstract
    In the current research, a cost-effective and modified method with a high degree of reproducibility was proposed for the preparation of fine nanoscale and high-purity BaTiO3. In contrast to the other established methods, in this research, carbonate-free BaTiO3 nanopowders were prepared at a lower temperature and in a shorter time span. To reach an in-depth understanding of the scientific basis of the proposed process, an in-detail analysis was carried out for characterization of nanoscale BaTiO3 particles via differential thermal analysis (DTA)/thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and...