Sharif Digital Repository

The goal of this project was study on coordination behavior of the 14-membered macrocyclic ligand of type N2O2 aza-crown while it is attached to fullerene C60 nano-particle. For this purpose, firstly the macrocyclic ligand (Fig 3-1, L1) was synthesized and then was reacted with C60 (Fig 3-1, L2) of which the product was characterized by elemental analysis. Since the product was insoluble in any solvents, further study on its coordination chemistry was impossible. In a second procedure, the macrocyclic ligand was reacted with benzylbromide. The reaction mixture gave two macrocyclic ligands with different number of benzylic pendant groups (Fig 3-1, L3-L4). The products were separated by column... 

Agriculture accounts for 70% of global freshwater consumption. However, precise data on irrigation water use (IWU) at the regional scale is often lacking, which hampers the development of effective water management plans. This study aims to estimate irrigation water use (IWU) by integrating remote sensing soil moisture (SM) and actual evapotranspiration (ET) data into a root-zone soil water model. Since irrigation influences both SM and actual ET, increases in SM and ET following irrigation events can be leveraged to frequently retrieve IWU from remotely sensed data. In this regard, we first developed an irrigation-free soil water model simulating root-zone SM dynamics during non-growing... 

Due to the data centers rapid growth and introduction of a new basic type of massive data processing platforms which requires accelerators to speedup computation and enhance the efficiency and reduce power consumption, using accelerators is inevitable. Communication and data transfer time between software and hardware is the most of time spent on the use of accelerators. By optimizing this part of the hardware / software platform, we have achieved substantial results in this area. The aim of our study is to organize a survey of real accelerator characteristics. To figure out its defects and main drawbacks, in addition to improving the overall efficiency of system. The implementation of... 

Coverage rate is a critical criterion in all of communication networks. In this regard, there are many different methods for distribution of network particles duo to attain the most efficient region of coverage. This emerges from the limited ability of each networks particle both in range of communicate and power consumption. In this thesis an evolutionary method is introduced to how Wireless Sensor Networks (WSN) particles can be dispensed to have more reliable coverage rate. Using both static and mobile sensor packages to cover the desired area and used a cost function, coverage rate, the authors tried to maximize it to have an excellent performance of network. Then proposed algorithm is... 

Ray-tracing method is extensively used for wave propagation analysis of indoor and outdoor environment for narrowband systems. The main goal of this research is to extend ray-tracing method for site-specific modeling of wideband electromagnetic propagation. In this thesis, Time-domain reflection and transmission coefficients have been computed for dielectric half-space and dielectric slab with frequency dependent permittivity. First, analytical form of Fresnel reflection coefficient for vertical and parallel polarizations in time-domain have been computed for dispersive half-spaces with lossy, extended Debye, two-pole Debye and multi-pole Debye models. By using these time-domain...