Sharif Digital Repository

In this thesis, gas-liquid two phase flow through channels of spatially varying cross-sections are investigated numerically. These flows have several industrial applications such as nozzles, diffusers, pipeline blowdown, valves and channels with sudden expansions or contractions. Finite volume method in conjunction with a second order Advection Upstream Splitting Method (AUSM+_up) is employed to discretize the governing equations. At low Mach numbers, a pressure-based algorithm with a pressure correction equation is derived. Using the pressure-based algorithm accelerates the convergence rate of the numerical solution of the flows through sudden expansions. The pressure adjacent to 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  

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 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... 

In multi-label classification problems each instance can simultaneously have multiple labels. In these problems, in addition to the complexities of the input feature space we encounter the complexities of output label space. In the multi-label classification problems, there are dependencies between different labels that need to be considered. Since the dimensionality of the label space in real-world applications can be (very) high, most methods which explicitly model these dependencies are ineffective in practice and recently those methods that transform the label space into a latent space have received attention. A class of these methods which uses output space dimension reduction, first... 

Buried pipelines as vital arteries,which will play a major role in human life should be designed and implemented in such a way that withstand the least possible harm with regard economic issues.In this study we tried to use a physical model, the impact of pipeline buried in soil slope under dynamic load are examined.To achive this goal we use a rigid metal bax with dimensions of 301.5*101.5*155 cubic meters for modeling. Pipes used in these experiments has a diameter of 1.6 cm which are connected by a fulcrum to the wall box. In order to measure strain generated in the pipe we use a series of strain gauges that were installed using the pipe at some points. Physical models made on Sharif...