Sharif Digital Repository

Influence of attachment of Multi Walled Carbon Nanotubes (MWCNT) on various nickel nanocatalysts produced by the electroless plating method was investigated via Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), Atomic Absorption Spectroscopy (AAS), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) measurements, Temperature Programmed Reduction (TPR) and Temperature Programmed Oxidation (TPO) tests. Application of TPR/TPO data to Kissinger (Redhead) Equation yielded the activation energies of both nickel reduction and nickel oxidation reactions. Addition of MWCNT improved the catalytic effects by easing of... 

Jets originating from bottom (b) quarks, play an important role in the study of Standard Model processes together with the search for new physics. In the CMS experiment a considerable e?ort is dedicated to the development and the performance study of so-called b-tagging algorithms. On the other hand, the top quark which is produced in pair (tt¯) with a high rate at the LHC, decays near 99% of the time to a b-quark. Hence it provides a rich source of b-quark jets, suitable for b-jet identi?cation studies. In this thesis, a fully data-driven method to measure the b-tagging e?ciency, using top quark events in its semi-electron ?nal state, is developed. The results of the application of the... 

In this Thesis we study the string theory discription of non-relativistic quantum ?eld theories.In other statement we study the duality between gravity and gauge theory with non-relativistic symmetry.We discuss that this duality works in non rel- ativistic sense.We study two kind of non-relativistic theories that one of them camefrom string theory and other model obtained by special transformation of original relativistic theory and we see that how duality can be work for these models.Also dual picture of semi-classical string in the background that found from string theorystudied.We also study the motion of particle in a hot plasma and we ?nd a sign of non-relativisic duality really works  

Image super-resolution is the process of estimating a high-quality image from a low-quality image. With the growth of remote sensing images, computer games, and the development of artificial intelligence applications in medical image analysis, research in this area of machine vision has seen significant growth. In recent years, research on super-resolution has primarily focused on the development of unsupervised models, blind networks, and the use of optimization methods in non-blind models. However, limited research has discussed the loss function in the super-resolution process. The majority of those studies have only used perceptual similarity in a conventional way. This is while the... 

In this thesis at ?rst, we review the magnetic monopole with andwithout electric charge in the ?at and also in the curved space and wereview the multimonopoles with axial and crystalline symmetry. In thisthesis also we review the holography principle and AdS/CFT duality andthe holographic renormalization. as the main part of the thesis the Julia-Zee dyon is studied in the context of AdS/CFT correspodence. We showthat for a solution of the dyon, the scalar ?eld in the model plays the roleof an order parameter. At high temperatures the vacuum expectationvalue of the dual scalar operator is zero and by lowering the temperature,it becomes nonzero and dual ?eld theory experiences a phase... 

Exact Renormalization Equations (ERGE) are powerful non-perturbative tools to study the dynamics of Quantum Field theories, with respect to the change of energy. Putting cut-off on momentums of the system, is the specific regularization that is used to obtain ERGEs. This regularization breaks the gauge symmetry in the case of gauge theories. So the symmetry will be lost through the energy flow as well.Finding a gauge symmetry for a regularized system is the aim of this research. Also we have investigated the related ERGEs and the behavior of symmetry through the flow  

Up to now, many seismic design methods and construction technologies have been investigated to reduce the seismic responses of bridges, buildings and potentially vulnerable structures. [1] Introducing a new effective systems aim to control of vibration caused by earthquake on the structures will be useful. This system is based on repelling of imposed force to the structures with tuned mass dampers (TMDs), to gain minimum damage. The detuning of the structures by equipped with TMDs resulted from nonlinear behavior due to dynamic loads such as strong ground motions are real concern in the practical applications. The application of TMDs, as expected, can reduce the deformation of the...