Sharif Digital Repository

Anomalous top quark interactions with gluon (tug , tcg) allow the production of single top quarks at the LHC. Two main sources of backgrounds which we took into account are W +1j and standard model single top production. In order to do it, we examine the reconstructed angular distribution of the charged lepton in the rest frame of W boson from the top quark. It is defined in terms of the angle θ_l , between the charged lepton momentum in the rest frame of the W boson and the momentum of the W boson in the rest frame of the top quark. Using this angular distribution of the charged lepton from the W boson in the top decay، we show that with the data of 10fb^(-1) of integrated luminosity and... 

Models wih extra dimensions have been among the most important models built for solving the problems of the standard model. In the standard model, Higgs mechanism is used to ex-plain electroweak symmetry breaking. One of the theoretical problems of the standard model,the hierchy problem, is about the Higgs mass being unnaturally small and models with extra dimensions have provided solutions to solve the problem. Moreover, extra dimensions pro-vide tools using which several models have been developed to explain electroweak symmetry breaking. In this thesis, acher reviewing the electroweak symmetry breaking sector of the stan-dard model, and the hierarchy problem, some models of electroweak... 

Today, many evidences, including the distribution of galactic velocities, gravitational lensing observations, and the cosmic microwave background, show that there exist dark matter (non-baryon matter) in large-scale cosmological structures that are stable, free of charge and without color, which has gravitational interaction like normal matter. The hypothesis that weakly interacting massive particles (WIMPs) as a dark matter candidate with mass range of several tens of GeV to several teV and with the typical couplings of Electroweak order of magnitude, is an attractive and desirable model, Which naturally explains the density of cosmic dark matter in agreement with observations. Alongside... 

In the first part of this thesis, the application of metal oxide nanoparticles in oxidative degradation of methylene blue is discussed. Nanoparticles of manganese tungstate (MnWO4) were prepared via an impregnation method using Mn(NO3)2.4H2O and WO3 as a source of Mn and W, respectively. The morphology of the manganese tungstate nanoparticles was studied in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). MnWO4 nanoparticles showed severe catalytic performance for the degradation of organic dye (methylene blue) in the presence of tertiary-butyl hydrogen peroxide, TBHP, as the oxidant at room temperature in water. Mn doped ZnO... 

Epoxidation of alkenes by Mn(III)meso-tetra(4-sulfonatophenyl)porphyrin chloride (MnTPPS4Cl) in the various homogeneous and heterogeneous catalytic systems was investigated. In the case of homogeneous catalysis, epoxidation of cyclooctene in CH2Cl2/MeOH mixture using urea hydrogen peroxide (UHP) as an oxidant and imidazole as a co-catalyst results in the formation of cycloocetene oxide in 87% yield. Using this catalytic system various alkenes successfully oxidized to their corresponding epoxide in high conversions and selectivity. Cyclic alkenes oxidized more easily than linear alkenes. In addition, epoxidation of alkenes was investigated in the heterogeneous catalytic systems. For this... 

In this project a new dioxovanadium (V) complex of Schiff base ligand N`-[1-(2-hydroxynaphthyl)methylene]-2-hydroxy benzohydrazide was synthesized and fully characterized. This complex is a pentacoordinate one in which the dioxo groups are in cis form. For synthesis of this complex, first, the intermediate compound 2-hydroxy benzohydrazide was synthesized from hydrazine and methyl salicylate and condensed with 2-hydroxynaphthaldehyde to give the Schiff base ligand (H2NBD). Then from reaction of ligand and ammonium vanadate in DMF in 65 ̊C, the NH4[VO2(NBD)] was prepared. This complex was fully characterized by UV, NMR and IR spectroscopies and it’s application as catalyst in sulfoxidation... 

With the rapid increase in the number of vehicles and the limitations on the extension of transportation network infrastructure, the need for utilizing proper methods to reduce traffic congestion has become increasingly important. One way to reduce traffic congestion is to control the signal splitting of traffic lights. Model predictive control (MPC) has been utilized so far by using different models of traffic flow dynamics in this field. Due to the high computational effort of MPC at each step time, the real-time implementation for large-scale networks has become a big challenge. Store-And-forward (SAF) is one of the traffic flow models that, due to its simplicity, makes it possible to... 

Different parts of this research are focused on developing FO membranes and improving their performance. For this purpose, thin film composite (TFC) membranes with fixed composition of polyethersulfone/polyamide (PES/PA) have been used to investigate the effect of nanocomposites containing transition metal dichalcogenides (TMDs) on their performance. The support layer in all cases is PES, which is prepared through the phase inversion process and does not contain any nanofillers. The modification process takes place in the polyamide layer by dispersing the desired nanoparticles in the aqueous monomer solution necessary to form this active layer. Identification and characterization of... 

Considerable effort has been directed in recent years towards the transition metal complex catalyzed oxidation of organic compounds. Herein the synthsis of the iron complex of bis(oxazoline) ligand as a novel catalyst is reported, and the catalytic activity of this complex in oxidation of sulfides is investigated. Bis(2-oxazolynil)methane as ligand is prepared by condensation of diethylmalonate with 2-aminoethanole in 1:2 molar ratio and finally corresponding complex is synthesized by the reaction between FeCl3.6H2O and Bis(2-Oxazolynil)methane in 1:1 molar ratio. The complex is characterized by using IR, UV-Vis, cyclic voltametery, conductometery and elemental analysis data. Moreover,... 

In this project a wide-band inductorless Low Noise Amplifier (LNA) has been designed using 0.18 micrometer CMOS technology. The specification of this amplifier has been explored in frequency band of 330MHz to 10GHz. Wide-band input and output impedance matching, low Noise-Figure (NF), reasonable voltage gain and low power consumption are the main challenges of Low Noise Amplifier design. Without using an inductor a better overall performance of LNA in a wide frequency band as well as a lower chip area has been achieved. In this design a novel noise cancellation technique in common-gate topology has been used for lowering the Noise Figure of the LNA. Group Delay of the designed LNA, which is...