Search for: anisotropy
Total 162 records
A new approach for calculation of relaxation time and magnetic anisotropy of ferrofluids containing superparmagnetic nanoparticles, Article Journal of Mining and Metallurgy, Section B: Metallurgy ; Volume 48, Issue 1 , 2012 , Pages 81-88 ; 14505339 (ISSN) ; Hosseini, H. R. M ; Sharif University of Technology
In this work, a new approach is described for the calculation of the relaxation time and magnetic anisotropy energy of magnetic nanoparticles. Ferrofluids containing monodispersed magnetite nanoparticles were synthesized via hydrothermal method and then heated using the 10 kA/m external AC magnetic fields in three different frequencies: 10, 50 and 100 kHz. By measuring the temperature variations during the application of the magnetic field, the total magnetic time constant including both Brownian and Neel relaxation times can be calculated. By measuring the magnetic core size and hydrodynamic size of particles, the magnetic anisotropy can be calculated too. Synthesized ferrofluids were...
Article RILEM Bookseries ; Volume 11 , 2016 , Pages 37-48 ; 22110844 (ISSN) ; Karimi, M. M ; Tabatabaee, N ; Sharif University of Technology
Kluwer Academic Publishers 2016
Asphalt concrete is a heterogeneous and multi-phase material that consists of aggregates, asphalt binder, and pores. These components create a complex microstructure. There is no consensus on how to quantify the microstructure and the required parameters from two-dimensional images. The load transfer can be managed by aggregate-aggregate or aggregate-mastic interactions that depend on the gradation, aggregate internal structure, and asphalt binder viscoelastic properties. The most important internal structure indices affecting the behavior of HMA are aggregate orientation, contact orientation, contact length, and number of contact points. In this paper, the influence of aggregate structure...
Article Optoelectronics, Materials, and Devices for Communications, Beijing, 12 November 2001 through 15 November 2001 ; Volume 4580 , 2001 , Pages 399-406 ; 0277786X (ISSN) ; Rashidian, B ; SPIE ; Sharif University of Technology
In this paper, exact analytical forms of the normal surface and eigenpolarizations in anisotropic media are obtained. Both the permittivity and permeability tensors are supposed to be anisotropic, becoming simultaneously diagonal in the principal system of coordinates. The equation of normal surface in various forms and exact relations for eigenpolarizations are presented and their properties are discussed. Orthogonality relationships between the eigenmodes are also introduced. Sufficient conditions for existence of two, one, or no optical axes are throughly established. The analysis is extended for the case of electrically or magnetically optically active materials, and exact form of...
Azimuthal anisotropy of charged particles at high transverse momenta in Pb-Pb collisions at √s NN=2.76TeV, Article Physical Review Letters ; Volume 109, Issue 2 , July , 2012 ; 00319007 (ISSN) ; 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 ; Krammer, M ; Liko, D ; Mikulec, I ; Pernicka, M ; Rahbaran, B ; Rohringer, C ; Rohringer, H ; Schöfbeck, R ; Strauss, J ; Taurok, A ; Teischinger, F ; Wagner, P ; Waltenberger, W ; Walzel, G ; Widl, E ; Wulz, C. E ; Mossolov, V ; Shumeiko, N ; Suarez Gonzalez, J ; Bansal, S ; Cerny, K ; Cornelis, T ; De Wolf, E. A ; Janssen, X ; Luyckx, S ; Maes, T ; Mucibello, L ; Ochesanu, S ; Roland, B ; Rougny, R ; Selvaggi, M ; 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 ; Charaf, O ; 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 ; 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 ; Vanelderen, L ; Verwilligen, P ; Walsh, S ; Yazgan, E ; Zaganidis, N ; Basegmez, S ; Bruno, G ; 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 ; 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 ; Silva Do Amaral, S. M ; Soares Jorge, L ; Sznajder, A ; Anjos, T. S ; 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, 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 Moreno, B ; Osorio Oliveros, A. F ; Sanabria, J. C ; Godinovic, N ; Lelas, D ; Plestina, R ; Polic, D ; Puljak, I ; Antunovic, Z ; Dzelalija, M ; 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 ; 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 ; 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 ; Karim, M ; Le Bihan, A. C ; Van Hove, P ; Fassi, F ; Mercier, D ; Beauceron, S ; Beaupere, N ; Bondu, O ; Boudoul, G ; Brun, H ; 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 ; Duchardt, D ; Erdmann, M ; Güth, A ; Hebbeker, T ; Heidemann, C ; Hoepfner, K ; Klimkovich, T ; Klingebiel, D ; Kreuzer, P ; Lanske, D ; 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 ; Davids, M ; Flügge, G ; Geenen, H ; Geisler, M ; Haj Ahmad, W ; Hoehle, F ; Kargoll, B ; Kress, T ; Kuessel, Y ; Linn, A ; Nowack, A ; Perchalla, L ; Pooth, O ; Rennefeld, J ; Sauerland, P ; Stahl, A ; Aldaya Martin, M ; Sharif University of Technology
The azimuthal anisotropy of charged particles in Pb-Pb collisions at √s NN=2.76TeV is measured with the CMS detector at the LHC over an extended transverse momentum (p T) range up to approximately 60GeV/c. The data cover both the low-p T region associated with hydrodynamic flow phenomena and the high-p T region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v 2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60%...
Article 31st International Cosmic Ray Conference, ICRC 2009, Lodz, 7 July 2009 through 15 July 2009 ; 2009 ; Bahmanabadi, M ; Hedayati, H ; Sheidaei, F ; Anvari, A ; Samimi, J ; Sharif University of Technology
University of Lodz 2009
Previously it was shown that the most important inclination of the EAS events due to geomagnetic field is the effect over the secondary particles of them and the contribution of the primary is so small . These secondary particles are mostly e± and μ ±, so we limited our study over these particles. It was simulated over 520,000 EAS events with (ON) and without (OFF) geomagnetic field for our site (B0 = 28:1 μT i + 38:4 μT k, h = 1200m a.s.l.). It is observed a quite North-South anisotropy in ON events and a quite random anisotropy in OFF events. This anisotropy is comparable with the recorded results in our site (ALBORZ observatory), but the simulated anisotropy is a little more than the...
Article Experimental Astronomy ; Volume 15, Issue 1 , 2003 , Pages 13-27 ; 09226435 (ISSN) ; Ghomi, M. K ; Samimi, J ; Purmohammad, D ; Sharif University of Technology
We have studied anisotropy of cosmic rays with an Extensive AirShower(EAS) array in Tehran 1200 m above sea level. In analyzingthe data set, we have used appropriate techniques of analysis andconsidered environmental effects. An asymmetry has been observedin the azimuthal distribution of EAS of cosmic rays because ofmagnetic field of the Earth. © 2004 Kluwer Academic Publishers
Tensor spherical harmonics theories on the exact nature of the elastic fields of a spherically anisotropic multi-inhomogeneous inclusion, Article Journal of the Mechanics and Physics of Solids ; Volume 61, Issue 4 , April , 2013 , Pages 1124-1143 ; 00225096 (ISSN) ; Khorshidi, A ; Sharif University of Technology
Eshelby's theories on the nature of the disturbance strains due to polynomial eigenstrains inside an isotropic ellipsoidal inclusion, and the form of homogenizing eigenstrains corresponding to remote polynomial loadings in the equivalent inclusion method (EIM) are not valid for spherically anisotropic inclusions and inhomogeneities. Materials with spherically anisotropic behavior are frequently encountered in nature, for example, some graphite particles or polyethylene spherulites. Moreover, multi-inclusions/inhomogeneities/ inhomogeneous inclusions have abundant engineering and scientific applications and their exact theoretical treatment would be of great value. The present work is devoted...
Article 2011 7th Iranian Conference on Machine Vision and Image Processing, MVIP 2011 - Proceedings ; 2011 ; 9781457715358 (ISBN) ; Fatemizadeh, E ; Soltanian Zadeh, H ; Sharif University of Technology
In this paper, we compare registration results obtained using different diffusion maps extracted from diffusion tensor imaging (DTI). Fractional Anisotropy (FA) and Ellipsoidal Area Ratio (EAR) are two diffusion maps (indices) that may be used for image registration. First, we use FA maps to find deformation matrix and register diffusion weighted images. Then, we use EAR maps and finally we use both of FA and EAR maps to register diffusion weighted images. The difference between FA values before deformation and after registration using the FA alone or EAR alone has a median of 0.57 and using both of them has a median of 0.29. Therefore, the results of registration using both of the FA and...
Article Physics of Plasmas ; Volume 25, Issue 1 , 2018 ; 1070664X (ISSN) ; Sadighi Bonabi, R ; Sharif University of Technology
American Institute of Physics Inc 2018
The relativistic Weibel instability and temperature anisotropy can generate electron bunches of attosecond duration which makes it an attractive method for the generation and amplification of tunable ultrashort pulses. In this paper, the effect of the relativistic Weibel instability and temperature anisotropy on generating attosecond electron bunches is investigated. Calculations show that with the reduction relativistic parameter, γ, by a factor of 2, increasing 14.6% of the relativistic Weibel instability leads to about 62% reduction of the nanobunching gain saturation time and the density perturbation generated by the temperature anisotropy and the relativistic Weibel instability. The...
Dzyaloshinskii-Moriya interaction and anisotropy effects on the entanglement of the Heisenberg model, Article Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 79, Issue 4 , 2009 ; 10502947 (ISSN) ; Jafari, R ; Langari, A ; Sharif University of Technology
In this paper the effect of Dzyaloshinskii-Moriya interaction and anisotropy on the entanglement of Heisenberg chain has been studied. While the anisotropy suppresses the entanglement due to favoring of the alignment of spins, the DM interaction restores the spoiled entanglement via creation of the quantum fluctuations. Thermodynamic limit of the model and emerging of nonanalytic behavior of the entanglement have also been probed. The singularities of the entanglement correspond to the critical boundary separating different phases of the model. The singularity of the entanglement derivative approaches the critical point from the gapped phase and will be symmetric if both phases on the...
Article Physica C: Superconductivity and its Applications ; Volume 449, Issue 1 , 2006 , Pages 47-52 ; 09214534 (ISSN) ; Mumtaz, M ; Ahadian, M. M ; Iraji zad, A ; Sharif University of Technology
X-ray photo-emission spectroscopy (XPS) studies of Cu1-xTlxBa2Ca3Cu4 O12-y superconductor thin films have been carried out for understanding the mechanism of superconductivity and to find out the reasons for the increase of zero resistivity critical temperature Tc(R = 0) with post-annealing in a nitrogen atmosphere. It is observed from these studies that reduction of charge state of thallium is a source of doping of carriers to the CuO2 planes. The reduced charge state of thallium (i.e. Tl1+) promotes lower oxygen concentration in the charge reservoir layer, which possibly results in movement of electrons to the conducting CuO2 planes. The higher density of electrons in the CuO2 planes...
Article Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 77, Issue 3 , 2008 ; 10502947 (ISSN) ; Jafari, R ; Langari, A ; Sharif University of Technology
We have applied our recent approach to study the quantum-information properties of the anisotropic s=1/2 Heisenberg chain. We have investigated the underlying quantum-information properties such as the evolution of concurrence, entanglement entropy, nonanalytic behaviors, and the scaling close to the quantum critical point of the model. Both the concurrence and the entanglement entropy develop two saturated values after enough iterations of the renormalization of coupling constants. These values are associated with the two different phases, i.e., Néel and spin liquid phases. The nonanalytic behavior comes from the divergence of the first derivative of both measures of entanglement as the...
Article Journal of Alloys and Compounds ; Volume 386, Issue 1-2 , 2005 , Pages 43-46 ; 09258388 (ISSN) ; Iraji zad, A ; Dolati, A ; Ghasempour, R ; Sharif University of Technology
Ni-Fe and the Ni-Fe-Cr-Mo alloy films were electrodeposited from a chloride solution containing complexing compounds on ITO/glass substrates. AFM studies revealed a spherical structure for the alloy films with roughnesses from 10 up to 50 nm. The Ni-Fe-Cr-Mo alloy films were found to have a fine-grain structure. The quaternary alloy compounds containing up to 4% Cr and 2% Mo showed higher resistivity and little decrease in magnetoresistance (MR) relative to the Ni80Fe20 alloy compound. The MR of the quaternary alloy compounds was decreased for higher Cr and Mo contents. Moreover, the anisotropy (AMR) was also decreased by the addition of Cr and Mo to Permalloy films. Auger studies indicated...
Article Electronics Letters ; Volume 39, Issue 23 , 2003 , Pages 1690-1691 ; 00135194 (ISSN) ; Baghai Wadji, A. R ; Sharif University of Technology
A unified and robust method has been introduced to compute magnetostatic and electrostatic fields for nonperiodic excitations in periodically corrugated anisotropic structures. The method extends a previously published concept of modified phased-periodic Green's functions for solving flat-surface problems. Convergent results have been obtained for corrugations with aspect ratios exceeding 15. Novel elemental field distributions are presented as examples
Article 8th International Symposium on Numerical Models in Geomechanics, NUMOG 2002, 10 April 2002 through 12 April 2002 ; 2002 , Pages 61-66 ; 9789058093592 (ISBN) ; Nezami, E. G ; Sharif University of Technology
CRC Press/Balkema 2002
Stress-induced anisotropy appears during the course of deformation in response to the applied stresses. The distribution of contact normals may be a dominant source of stress-induced anisotropy in granular assemblies. In the present study, stress-induced anisotropy in the fabric of granular materials is investigated through implication of several strain-controlled biaxial compression simulations on random assemblies of oval cross-sectional particles with mixed sizes. Based on a new formulation for distinct element method (DEM), which is referred to as static DEM (SDEM), an efficient computer program is developed to observe the evolution of the fabric in assemblies of oval granules under...
Article Mathematical Geosciences ; Vol. 45, issue. 3 , April , 2013 , p. 321-340 ; ISSN: 18748961 ; Masihi, M ; Pishvaie, M ; King, P. R ; Sharif University of Technology
Complicated sedimentary processes control the spatial distribution of geological heterogeneities. This serves to make the nature of the fluid flow in the hydrocarbon reservoirs immensely complex. Proper modeling of these heterogeneities and evaluation of their connectivity are crucial and affects all aspects of fluid flow. Since the natural variability of heterogeneity occurs in a myriad of length scales, accurate modeling of the rock type connectivity requires a very fine scheme, which is computationally very expensive. Hence, this makes other alternative methods such as the percolation approach attractive and necessary. The percolation approach considers the hypothesis that a reservoir can...
Effects of thickness and texture on mechanical properties anisotropy of commercially pure titanium thin sheets, Article Materials and Design ; Volume 44 , February , 2013 , Pages 528-534 ; 02641275 (ISSN) ; Ekrami, A ; Ziaei Moayyed, A. A ; Sharif University of Technology
Simultaneous effects of thickness and texture on the anisotropy of mechanical properties and fracture behaviors of commercially pure titanium thin sheets were studied. The activation of different deformation systems, due to the split distribution of basal texture, led to mechanical properties anisotropy. The crack initiation and propagation energies, when the loading direction was parallel to the initial rolling direction, decreased with increasing thickness ranges from 0.25 to 1 mm. The changes of size, shape and distribution of dimples with increasing thickness confirmed the restriction of deformation systems and the development of triaxial stress state and plane-strain condition at the...
Article Proceedings of SPIE - The International Society for Optical Engineering ; Volume 8480 , 2012 ; 0277786X (ISSN) ; 9780819491978 (ISBN) ; Sharif University of Technology
We discuss the deflection of light and Shapiro delay under the influence of gravity as described by Schwarzschild metric. We obtain an exact expression based on the coordinate velocity, as first set forth by Einstein, and present a discussion on the effect of velocity anisotropy. We conclude that the anisotropy in the coordinate velocity, as the velocity apparent to a distant observer, gives rise to a third order error in the deflection angle, so that the practical astronomical observations from gravitational lensing data remain inconclusive on the anisotropy. However, measurement of Shapiro delay provides a fairly convenient way to determine whether the spacetime is optically anisotropic...
Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 84, Issue 2 , 2011 ; 15393755 (ISSN) ; Ghasemi, F ; Rahvar, S ; Tabar, M. R. R ; Sharif University of Technology
We investigate the statistical anisotropy and Gaussianity of temperature fluctuations of Cosmic Microwave Background (CMB) radiation data from the Wilkinson Microwave Anisotropy Probe survey, using the Multifractal Detrended Fluctuation Analysis, Rescaled Range, and Scaled Windowed Variance methods. Multifractal Detrended Fluctuation Analysis shows that CMB fluctuations has a long-range correlation function with a multifractal behavior. By comparing the shuffled and surrogate series of CMB data, we conclude that the multifractality nature of the temperature fluctuation of CMB radiation is mainly due to the long-range correlations, and the map is consistent with a Gaussian distribution
Coupling microplane-based damage and continuum plasticity models for analysis of damage-induced anisotropy in plain concrete, Article International Journal of Plasticity ; Volume 95 , 2017 , Pages 216-250 ; 07496419 (ISSN) ; Ghaemian, M ; Sharif University of Technology
Elsevier Ltd 2017
A novel plastic-damage constitutive model for plain concrete is developed in this paper. For this purpose, the microplane theory is proposed for overcoming the deficiency of available anisotropic continuum plastic-damage models in reproducing the true anisotropic nature of damage in multidimensional loadings. Based on the microplane theory, the degeneration process in concrete is considered along with plastic deformations. Using the principle of strain energy equivalence, a transformation between the nominal and effective states of material is achieved, that results in a decoupled formulation for damage and plasticity. A yield function with multiple internal variables and a non-associative...