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    "Energy Finite Element Method for High Frequency Random Vibrations Analysis of a Reinforced Beam-Plate with a Cutout and Experimental Validation "

    , M.Sc. Thesis Sharif University of Technology Nokhbatolfoghahai, Ali (Author) ; Haddadpour, Hassan (Supervisor) ; Mohammad Navazi, Hossein (Supervisor)
    Abstract
    In this thesis, the high frequency random vibrations analysis of a reinforced plate with a cutout is carried out using Energy Finite Element Analysis (EFEA) and the final results are validated with experimental results. EFEA method uses the average energy density as the primary variable to form the governing differential equations of energy flow in the structure. In this method the equations of space and time averaged energy density are derived in the Far Field and the energy intensity is considered as continues variable over the structure. In this work, at first for simple beam and plate an EFEA code is developed. Then the relationships for joints are derived using structural dynamics. Some... 

    Kinematic and Constitutive Modeling of Elastic and Thermoelastic Continua with Finite Deformation using Multiplicative Decomposition of Deformation Gradient

    , Ph.D. Dissertation Sharif University of Technology Darijani, Hossein (Author) ; Naghdabadi, Reza (Supervisor) ; Kargarnovin, Mohammad Hassan (Supervisor)
    Abstract
    In this thesis, a deformation measure is introduced which leads to a class of strain measures in the Lagrangian and Eulerian descriptions. In order to develop a constitutive equation, a second-order constitutive relation based on these strain measures is considered for modeling the mechanical behavior of solids at finite deformation. For this purpose and performance evaluation of the proposed strains, a Hookean-type constitutive equation is considered and the uniaxial loading as well as simple shear and pure shear tests are examined and the results are compared with the test data. Also, in order to characterize the mechanical behavior of elastic continua, constitutive equations through a... 

    A Hierarchy of Plate Models Derived from Nonliinear Elasticity by T-Convergence

    , M.Sc. Thesis Sharif University of Technology Golipoor, Javad (Author) ; Bahraini, Alireza (Supervisor)
    Abstract
    In this thesis the elastic energy of plates is computed. Primarily, some physical related concepts such as stress, strain and strain energy density are defined. Then based on rigidity estimate theorem, the gradient map on bounded Lipschitz domains is approximated by a constant rotation map R.Thanks to this approximation theorem,we prove the precompactness of sequences of finite bending energy, and the limiting energy of two dimensional thin plates is shown to be an elastic energy. This limit innovation is called Γ –convergence introduced in 1993. It will indeed be revealed that the induced elastic energy of a deformable body is the limit of the sequence of stored energy of body under... 

    Measurement of the pseudorapidity and centrality dependence of the transverse energy density in pb-pb collisions at √s NN=2.76TeV

    , Article Physical Review Letters ; Volume 109, Issue 15 , 2012 ; 00319007 (ISSN) Chatrchyan, S ; Khachatryan, V ; Sirunyan, A. M ; Tumasyan, A ; Adam, W ; Bergauer, T ; Dragicevic, M ; Erö, J ; Fabjan, C ; Friedl, M ; Frühwirth, R ; Ghete, V. M ; Hammer, J ; Hörmann, N ; Hrubec, J ; Jeitler, M ; Kiesenhofer, W ; Knünz, V ; Krammer, M ; Liko, D ; Mikulec, I ; Pernicka, M ; Rahbaran, B ; Rohringer, C ; Rohringer, H ; Schöfbeck, R ; Strauss, J ; Taurok, A ; Wagner, P ; Waltenberger, W ; Walzel, G ; Widl, E ; Wulz, C. E ; Mossolov, V ; Shumeiko, N ; Suarez Gonzalez, J ; Bansal, S ; Cornelis, T ; De Wolf, E. A ; Janssen, X ; Luyckx, S ; Maes, T ; Mucibello, L ; Ochesanu, S ; Roland, B ; Rougny, R ; Selvaggi, M ; Staykova, Z ; Van Haevermaet, H ; Van Mechelen, P ; Van Remortel, N ; Van Spilbeeck, A ; Blekman, F ; Blyweert, S ; D'hondt, J ; Gonzalez Suarez, R ; Kalogeropoulos, A ; Maes, M ; Olbrechts, A ; Van Doninck, W ; Van Mulders, P ; Van Onsem, G.P ; Villella, I ; Clerbaux, B ; De Lentdecker, G ; Dero, V ; Gay, A. P. R ; Hreus, T ; Léonard, A ; Marage, P.E ; Reis, T ; Thomas, L ; Vander Velde, C ; Vanlaer, P ; Wang, J ; Adler, V ; Beernaert, K ; Cimmino, A ; Costantini, S ; Garcia, G ; Grunewald, M ; Klein, B ; Lellouch, J ; Marinov, A ; Mccartin, J ; Ocampo Rios, A. A ; Ryckbosch, D ; Strobbe, N ; Thyssen, F ; Tytgat, M ; Verwilligen, P ; Walsh, S ; Yazgan, E ; Zaganidis, N ; Basegmez, S ; Bruno, G ; Castello, R ; Ceard, L ; Delaere, C ; Du Pree, T ; Favart, D ; Forthomme, L ; Giammanco, A ; Hollar, J ; Lemaitre, V ; Liao, J ; Militaru, O ; Nuttens, C ; Pagano, D ; Pin, A ; Piotrzkowski, K ; Schul, N ; Vizan Garcia, J. M ; Beliy, N ; Caebergs, T ; Daubie, E ; Hammad, G. H ; Alves, G.A ; Correa Martins Junior, M ; De Jesus Damiao, D ; Martins, T ; Pol, M.E ; Souza, M. H. G ; Aldá Júnior, W. L ; Carvalho, W ; Custódio, A ; Da Costa, E.M ; De Oliveira Martins, C ; Fonseca De Souza, S ; Matos Figueiredo, D ; Mundim, L ; Nogima, H ; Oguri, V ; Prado Da Silva, W. L ; Santoro, A ; Soares Jorge, L ; Sznajder, A ; Bernardes, C. A ; Dias, F. A ; Fernandez Perez Tomei, T. R ; Gregores, E. M ; Lagana, C ; Marinho, F ; Mercadante, P. G ; Novaes, S. F ; Padula, S. S ; Genchev, V ; Iaydjiev, P ; Piperov, S ; Rodozov, M ; Stoykova, S ; Sultanov, G ; Tcholakov, V ; Trayanov, R ; Vutova, M ; Dimitrov, A ; Hadjiiska, R ; Kozhuharov, V ; Litov, L ; Pavlov, B ; Petkov, P ; Bian, J. G ; Chen, G. M ; Chen, H. S ; Jiang, C. H ; Liang, D ; Liang, S ; Meng, X ; Tao, J ; Wang, J ; Wang, X ; Wang, Z ; Xiao, H ; Xu, M ; Zang, J ; Zhang, Z ; Asawatangtrakuldee, C ; Ban, Y ; Guo, S ; Guo, Y ; Li, W ; Liu, S ; Mao, Y ; Qian, S. J ; Teng, H ; Wang, S ; Zhu, B ; Zou, W ; Avila, C ; Gomez, J. P ; Gomez Moreno, B ; Osorio Oliveros, A. F ; Sanabria, J. C ; Godinovic, N ; Lelas, D ; Plestina, R ; Polic, D ; Puljak, I ; Antunovic, Z ; Kovac, M ; Brigljevic, V ; Duric, S ; Kadija, K ; Luetic, J ; Morovic, S ; Attikis, A ; Galanti, M ; Mavromanolakis, G ; Mousa, J ; Nicolaou, C ; Ptochos, F ; Razis, P. A ; Finger, M ; Finger, M ; Assran, Y ; Elgammal, S ; Ellithi Kamel, A ; Khalil, S ; Mahmoud, M. A ; Radi, A ; Kadastik, M ; Müntel, M ; Raidal, M ; Rebane, L ; Tiko, A ; Azzolini, V ; Eerola, P ; Fedi, G ; Voutilainen, M ; Härkönen, J ; Heikkinen, A ; Karimäki, V ; Kinnunen, R ; Kortelainen, M. J ; Lampén, T ; Lassila-Perini, K ; Lehti, S ; Lindén, T ; Luukka, P ; Mäenpää, T ; Peltola, T ; Tuominen, E ; Tuominiemi, J ; Tuovinen, E ; Ungaro, D ; Wendland, L ; Banzuzi, K ; Karjalainen, A ; Korpela, A ; Tuuva, T ; Besancon, M ; Choudhury, S ; Dejardin, M ; Denegri, D ; Fabbro, B ; Faure, J. L ; Ferri, F ; Ganjour, S ; Givernaud, A ; Gras, P ; Hamel De Monchenault, G ; Jarry, P ; Locci, E ; Malcles, J ; Millischer, L ; Nayak, A ; Rander, J ; Rosowsky, A ; Shreyber, I ; Titov, M ; Baffioni, S ; Beaudette, F ; Benhabib, L ; Bianchini, L ; Bluj, M ; Broutin, C ; Busson, P ; Charlot, C ; Daci, N ; Dahms, T ; Dobrzynski, L ; Granier De Cassagnac, R ; Haguenauer, M ; Miné, P ; Mironov, C ; Nguyen, M ; Ochando, C ; Paganini, P ; Sabes, D ; Salerno, R ; Sirois, Y ; Veelken, C ; Zabi, A ; Agram, J. L ; Andrea, J ; Bloch, D ; Bodin, D ; Brom, J. M ; Cardaci, M ; Chabert, E. C ; Collard, C ; Conte, E ; Drouhin, F ; Ferro, C ; Fontaine, J. C ; Gelé, D ; Goerlach, U ; Juillot, P ; Le Bihan, A. C ; Van Hove, P ; Fassi, F ; Mercier, D ; Beauceron, S ; Beaupere, N ; Bondu, O ; Boudoul, G ; Chasserat, J ; Chierici, R ; Contardo, D ; Depasse, P ; El Mamouni, H ; Fay, J ; Gascon, S ; Gouzevitch, M ; Ille, B ; Kurca, T ; Lethuillier, M ; Mirabito, L ; Perries, S ; Sordini, V ; Tosi, S ; Tschudi, Y ; Verdier, P ; Viret, S ; Tsamalaidze, Z ; Anagnostou, G ; Beranek, S ; Edelhoff, M ; Feld, L ; Heracleous, N ; Hindrichs, O ; Jussen, R ; Klein, K ; Merz, J ; Ostapchuk, A ; Perieanu, A ; Raupach, F ; Sammet, J ; Schael, S ; Sprenger, D ; Weber, H ; Wittmer, B ; Zhukov, V ; Ata, M ; Caudron, J ; Dietz-Laursonn, E ; Erdmann, M ; Güth, A ; Hebbeker, T ; Heidemann, C ; Hoepfner, K ; Klingebiel, D ; Kreuzer, P ; Lingemann, J ; Magass, C ; Merschmeyer, M ; Meyer, A ; Olschewski, M ; Papacz, P ; Pieta, H ; Reithler, H ; Schmitz, S. A ; Sonnenschein, L ; Steggemann, J ; Teyssier, D ; Weber, M ; Bontenackels, M ; Cherepanov, V ; Flügge, G ; Geenen, H ; Geisler, M ; Haj Ahmad, W ; Hoehle, F ; Kargoll, B ; Kress, T ; Kuessel, Y ; Nowack, A ; Perchalla, L ; Pooth, O ; Rennefeld, J ; Sauerland, P ; Stahl, A ; Aldaya Martin, M ; Behr, J ; Behrenhoff, W ; Behrens, U ; Bergholz, M ; Bethani, A ; Borras, K ; Burgmeier, A ; Sharif University of Technology
    2012
    Abstract
    The transverse energy (E T) in Pb-Pb collisions at 2.76 TeV nucleon-nucleon center-of-mass energy (√s NN) has been measured over a broad range of pseudorapidity (η) and collision centrality by using the CMS detector at the LHC. The transverse energy density per unit pseudorapidity (dE T/dη) increases faster with collision energy than the charged particle multiplicity. This implies that the mean energy per particle is increasing with collision energy. At all pseudorapidities, the transverse energy per participating nucleon increases with the centrality of the collision. The ratio of transverse energy per unit pseudorapidity in peripheral to central collisions varies significantly as the... 

    A multi-scale modeling of surface effect via the modified boundary Cauchy-Born model

    , Article Materials Science and Engineering C ; Volume 32, Issue 7 , 2012 , Pages 1993-2000 ; 09284931 (ISSN) Khoei, A. R ; Aramoon, A ; Sharif University of Technology
    Elsevier  2012
    Abstract
    In this paper, a new multi-scale approach is presented based on the modified boundary Cauchy-Born (MBCB) technique to model the surface effects of nano-structures. The salient point of the MBCB model is the definition of radial quadrature used in the surface elements which is an indicator of material behavior. The characteristics of quadrature are derived by interpolating data from atoms laid in a circular support around the quadrature, in a least-square scene. The total-Lagrangian formulation is derived for the equivalent continua by employing the Cauchy-Born hypothesis for calculating the strain energy density function of the continua. The numerical results of the proposed method are... 

    Temperature-dependent multi-scale modeling of surface effects on nano-materials

    , Article Mechanics of Materials ; Volume 46 , 2012 , Pages 94-112 ; 01676636 (ISSN) Khoei, A. R ; Ghahremani, P ; Sharif University of Technology
    Abstract
    In this paper, a novel temperature-dependent multi-scale method is developed to investigate the role of temperature on surface effects in the analysis of nano-scale materials. In order to evaluate the temperature effect in the micro-scale (atomic) level, the temperature related Cauchy-Born hypothesis is implemented by employing the Helmholtz free energy, as the energy density of equivalent continua relating to the inter-atomic potential. The multi-scale technique is applied in atomistic level (nano-scale) to exhibit the temperature related characteristics. The first Piola-Kirchhoff stress and tangential stiffness tensor are computed, as the first and second derivatives of the free energy... 

    Anti-plane stress intensity, energy release and energy density at crack tips in a functionally graded strip with linearly varying properties

    , Article Theoretical and Applied Fracture Mechanics ; Volume 56, Issue 1 , 2011 , Pages 42-48 ; 01678442 (ISSN) Kargarnovin, M. H ; Nasirai, C ; Torshizian, M. R ; Sharif University of Technology
    Abstract
    The fracture problem of a crack in a functionally graded strip with its properties varying in a linear form along the strip thickness under an anti-plane load is considered. The embedded anti-plane crack is located in the middle of strip half way through the thickness. The third mode stress intensity factor is derived using two different methods. In the first method, by employing Fourier integral transforms, the governing equation is converted to a singular integral equation, which is subsequently solved numerically by the collocation method based on Chebyshev polynomials. Then, the problem is solved by means of finite element method in which quadrilateral 8-node singular elements around... 

    Multi-scale modeling of surface effect via the boundary Cauchy-Born method

    , Article International Journal for Numerical Methods in Engineering ; Volume 85, Issue 7 , August , 2011 , Pages 827-846 ; 00295981 (ISSN) Qomi, M. J. A ; Aghaei, A ; Khoei, A. R ; Sharif University of Technology
    2011
    Abstract
    In this paper, a novel multi-scale approach is developed for modeling of the surface effect in crystalline nano-structures. The technique is based on the Cauchy-Born hypothesis in which the strain energy density of the equivalent continua is calculated by means of inter-atomic potentials. The notion of introducing the surface effect in the finite element method is based on the intrinsic function of quadratures, called as an indicator of material behavior. The information of quadratures is derived by interpolating the data from probable representative atoms in their proximity. The technique is implemented by the definition of reference boundary CB elements, which enable to capture not only... 

    Biodegradable ionic liquids: effects of temperature, alkyl side-chain length, and anion on the thermodynamic properties and interaction energies as determined by molecular dynamics simulations coupled with ab initio calculations

    , Article Industrial and Engineering Chemistry Research ; Volume 54, Issue 46 , November , 2015 , Pages 11678-11700 ; 08885885 (ISSN) Fakhraee, M ; Gholami, M. R ; Sharif University of Technology
    American Chemical Society  2015
    Abstract
    The effects of incorporating the ester functional group (-C=OO-) into the side chain of the 1-alkyl-3-methylimidazolium cation ([C1COOCnC1im]+, n = 1, 2, 4) paired with [Br]-, [NO3]-, [BF4]-, [PF6]-, [TfO]-, and [Tf2N]- anions on the various thermodynamic properties and interaction energies of these biodegradable ionic liquids (ILs) were investigated by means of molecular dynamics (MD) simulations combined with ab initio calculations in the temperature range of 298-550 K. Excluding the simulated density, the highest values of the volumetric properties such as molar volume, isobaric expansion coefficient, and isothermal compressibility coefficient can be attributed to the largest cation... 

    Frequency-dependent energy harvesting via magnetic shape memory alloys

    , Article Smart Materials and Structures ; Volume 24, Issue 11 , October , 2015 ; 09641726 (ISSN) Sayyaadi, H ; Askari Farsangi, M. A ; Sharif University of Technology
    Institute of Physics Publishing  2015
    Abstract
    This paper is focused on presenting an accurate framework to describe frequency-dependent energy harvesting via magnetic shape memory alloys (MSMAs). Modeling strategy incorporates the phenomenological constitutive model developed formerly together with the magnetic diffusion equation. A hyperbolic hardening function is employed to define reorientation-induced strain hardening in the material, and the diffusion equation is used to add dynamic effects to the model. The MSMA prismatic specimen is surrounded by a pickup coil, and the induced voltage during martensite-variant reorientation is investigated with the help of Faraday's law of magnetic field induction. It has been shown that, in... 

    An exact analysis for the hoop elasticity and pressure-induced twist of CNT-nanovessels and CNT-nanopipes

    , Article Mechanics of Materials ; Volume 82 , 2015 , Pages 47-62A ; 01676636 (ISSN) Delfani, M. R ; Shodja, H. M ; Sharif University of Technology
    Elsevier  2015
    Abstract
    Carbon nanotubes (CNTs) with and without end caps may be used for fluid storage and transport, respectively, referred to as CNT-nanovessel and CNT-nanopipe. The determination of the stiffness in the hoop (circumferential) and radial directions, ideal hoop strength, and hoop stress-strain curve of such nanostructures is of particular interest. Due to the proposed viewpoint, a chiral free-standing single-walled CNT (SWCNT) has a natural angle of twist and natural extension along the axis of the tube. For example, for the SWCNT (9,3) with diameter of 0.85 nm and chirality angle of 13.9°, the natural angle of twist per unit length is 1.45×10-3 rad/nm. Previously, only Vercosa et al. (2010) who... 

    Constitutive modeling of rubberlike materials based on consistent strain energy density functions

    , Article Polymer Engineering and Science ; Volume 50, Issue 5 , 2010 , Pages 1058-1066 ; 00323888 (ISSN) Darijani, H ; Naghdabadi, R ; Kargarnovin, M. H ; Sharif University of Technology
    Abstract
    Rubberlike materials are characterized by high deformability and reversibility of deformation. From the continuum viewpoint, a strain energy density function is postulated for modeling the behavior of these materials. In this paper, a general form for the strain energy density of these materials is proposed from a phenomenological point of view. Based on the Valanis-Landel hypothesis, the strain energy density of incompressible materials is expressed as the sum of independent functions of the principal stretches meeting the essential requirements on the form of the strain energy density. It is cleared that the appropriate mathematical expressions for constitutive modeling of these materials... 

    Hyperelastic materials behavior modeling using consistent strain energy density functions

    , Article Acta Mechanica ; Volume 213, Issue 3-4 , 2010 , Pages 235-254 ; 00015970 (ISSN) Darijani, H ; Naghdabadi, R ; Sharif University of Technology
    Springer-Verlag Wien  2010
    Abstract
    Hyperelastic materials have high deformability and nonlinearity in load-deformation behavior. Based on a phenomenological approach, these materials are treated as a continuum, and a strain energy density is considered to describe their hyperelastic behavior. In this paper, the mechanical behavior characterization of these materials is studied from the continuum viewpoint. For this purpose, the strain energy density is expressed as sum of independent functions of the mutual multiple of principal stretches. These functions are determined by applying the governing postulates on the form of the strain energy density. It is observed that a consistent strain energy density is expressible in terms... 

    Hyperelastic materials modelling using a strain measure consistent with the strain energy postulates

    , Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 224, Issue 3 , 2010 , Pages 591-602 ; 09544062 (ISSN) Darijani, H ; Naghdabadi, R ; Kargarnovin, M. H ; Sharif University of Technology
    Abstract
    In this article, a strain energy density function of the Saint Venant-Kirchhoff type is expressed in terms of a Lagrangian deformation measure. Applying the governing postulates to the form of the strain energy density, the mathematical expression of this measure is determined. It is observed that this measure, which is consistent with the strain energy postulates, is a strain type with the characteristic function more rational than that of the Seth-Hill strain measures for hyperelastic materials modelling. In addition, the material parameters are calculated using a novel procedure that is based on the correlation between the values of the strain energy density (rather than the stresses)... 

    Numerical investigation of crack orientation in the fretting fatigue of a flat rounded contact

    , Article International Journal of Engineering, Transactions B: Applications ; Volume 23, Issue 3-4 , 2010 , Pages 223-232 ; 1728-144X (ISSN) Mohajerani, A ; Farrahi, G. H ; Sharif University of Technology
    Materials and Energy Research Center  2010
    Abstract
    The growth of slant cracks by fretting fatigue of a half plane in contact with a flat rounded pad was studied. The mode I and mode II stress intensity factors for cracks of various lengths and directions were calculated using the semi-analytical method of the distribution of dislocations, and their cumulative effect on the crack growth was investigated using the strain energy density criterion. The results showed dominance of mode I fracture on crack growth, and based on the observation of strain energy density factor versus crack orientation, the results also suggest that depending on the crack length, the most critical orientations of cracks are at 0° to 20° outward the contact zone. Good... 

    Micromechanics and constitutive modeling of connective soft tissues

    , Article Journal of the Mechanical Behavior of Biomedical Materials ; Volume 60 , 2016 , Pages 157-176 ; 17516161 (ISSN) Fallah, A ; Ahmadian, M. T ; Firozbakhsh, K ; Aghdam, M. M ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    In this paper, a micromechanical model for connective soft tissues based on the available histological evidences is developed. The proposed model constituents i.e. collagen fibers and ground matrix are considered as hyperelastic materials. The matrix material is assumed to be isotropic Neo-Hookean while the collagen fibers are considered to be transversely isotropic hyperelastic. In order to take into account the effects of tissue structure in lower scales on the macroscopic behavior of tissue, a strain energy density function (SEDF) is developed for collagen fibers based on tissue hierarchical structure. Macroscopic response and properties of tissue are obtained using the numerical... 

    A novel isolated DC/DC converter for fuel cell powered load

    , Article 2009 IEEE Electrical Power and Energy Conference, EPEC 2009, 22 October 2009 through 23 October 2009 ; 2009 ; 9781424445080 (ISBN) Fathi, A. H ; Hoseinnia, S ; Roshandel, R ; Sharif University of Technology
    Abstract
    Fuel Cell (FC) is one of the promising distributed generation resources which are based on renewable energies. Clean electricity generation, high efficiency and high energy density of the fuel cells make them attractive for lots of engineers. In this paper we discuss about the operational principles of fuel cell generally. Then, a circuit model of them will be introduced. Based on the model, we designed a novel DC/DC converter for supplying the fuel cell's load and simulated the design with using Matlab. The results say that its novel converter could conveniently supply the load and its needed power curve. ©2009 IEEE  

    A study of hyperelastic models for predicting the mechanical behavior of extensor apparatus

    , Article Biomechanics and Modeling in Mechanobiology ; Volume 16, Issue 3 , 2017 , Pages 1077-1093 ; 16177959 (ISSN) Elyasi, N ; Karimi Taheri, K ; Narooei, K ; Karimi Taheri, A ; Sharif University of Technology
    Springer Verlag  2017
    Abstract
    In this research, the nonlinear elastic behavior of human extensor apparatus was investigated. To this goal, firstly the best material parameters of hyperelastic strain energy density functions consisting of the Mooney–Rivlin, Ogden, invariants, and general exponential models were derived for the simple tension experimental data. Due to the significance of stress response in other deformation modes of nonlinear models, the calculated parameters were used to study the pure shear and balance biaxial tension behavior of the extensor apparatus. The results indicated that the Mooney–Rivlin model predicts an unstable behavior in the balance biaxial deformation of the extensor apparatus, while the... 

    General solution to wave propagation in media undergoing arbitrary transient or periodic temporal variations of permittivity

    , Article Journal of the Optical Society of America B: Optical Physics ; Volume 35, Issue 11 , 2018 , Pages 29232932- ; 07403224 (ISSN) Chegnizadeh, M ; Mehrany, K ; Memarian, M ; Sharif University of Technology
    OSA - The Optical Society  2018
    Abstract
    A novel and general formulation for wave propagation in time-varying media is presented. Unlike previousreports, our formalism is able to solve propagation in media with arbitrary time variations of permittivity orpermeability, for both transient and steady-state periodic variations. The formulation is approximate yet strikingly accurate in most practical cases. The provided closed-form expressions show that the normalized averagepower after the transition of the permittivity does not depend on the details of the transition, while the energydensity does. Some important discussions are made about time-periodic media, and it is shown that there is anaccumulation of energy when the temporal... 

    Synthesis, crystal structure and DNA interaction of a new water-soluble derivative of pyrazino[2,3-f][1,10] phenanthroline; theoretical calculations, experimental and molecular docking studies

    , Article Journal of Molecular Structure ; Volume 1165 , 2018 , Pages 267-275 ; 00222860 (ISSN) Aminzadeh, M ; Eslami, A ; Kia, R ; Aleeshah, R ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    The new water-soluble derivative of pyrazino[2,3-f][1,10] phenanthroline has been synthesized and characterized by conductivity measurement, elemental analysis, FT-IR, 1H NMR, 13C NMR spectroscopic studies, as well as single crystal x-ray crystallography. Theoretical calculations have been performed using the density functional theory (DFT) in order to confirm the structure and understand the electronic structure of the synthesized compound. The DNA binding properties of the compound were investigated by absorption spectroscopy, melting temperature and viscosity measurements. The intrinsic binding constant, Kb, was determined as 7.84 × 103 M−1 at 298 K. Thermodynamic parameters showed that...