Sharif Digital Repository

The magnetic MOF-based catalytic system has been reported here to be an efficient catalyst for synthesis of carbamates under optimal conditions. The robust MOF catalyst was built based on magnetic nanoparticles and HKUST-1 which further modified with thioacetamide and carbonization. The catalyst structure was confirmed by various techniques. Furthermore, the products’ yields were obtained in good to excellent for all reactions under mild conditions which result from superior activity of the synthesized heterogeneous catalyst containing Cupper. Also, the magnetic property of the MOF-based catalyst makes it easy to separate from reaction mediums and reuse in the next runs. In summary, the... 

A broad range of plain carbon steels have ferrite-pearlite microstructures, which are used in many industrial applications due to the good strength and formability provided by the typical combination of ferrite grains and pearlite colonies. The mechanical behavior of ferrite-pearlite steels inherently originates from the configurations of ferrite grains and pearlite colonies, which comprised alternating lamellae of cementite with randomly distributed orientations in a ferrite matrix. In this thesis, three different experimental-numerical approaches were employed to investigate the deformation behavior, damage mechanisms, and formability of the ferrite-pearlite steels. At the first step, two... 

By the advance of wireless communication systems, requirements to more advanced systems is increased. Circularly polarized antennas are considered as a robust solution to the demands of contemporary systems because of their unique attributes. This polarization is being used in various systems like satellite communication, global navigation system, mobile communications, wireless sensors, radio frequency identification, wireless power transmission and etc. Different designs are proposed to achieve circular polarization which among them the ones using single feeding techniques are more favored because of their ease of fabrication and excitation. In this thesis, three circularly polarized... 

In the first section, due to the important role of nanocatalysts in different fields of chemistry, magnetic metal ferrite nanoparticles were synthesized. Ferrite nanoparticles were synthesized using co-precipitation method and were characterized. Then, these nanoparticles were applied as catalyst system for one-pot β-ketophosphonates and thiophosphate synthesis.This is a green and efficient route for S-P and C-P bond construction using copper ferrite nanoparticles as catalyst. The application of a highly active recyclable heterogeneous nanocopper ferrite catalyst for the oxyphosphorylation reaction of various alkenes was conducted under ligand-free conditions, in acetonitrile as solvent at... 

Non-reciprocity in electromagnetics has been used in the design of various devices for microwave frequencies to optics. Non-reciprocity at radio frequencies and microwaves has thus far been mainly achieved by a group of magnetic materials. Ferrites are a very suitable option due to their low magnetic losses and high electrical resistance, and utilized in design and manufacture of isolators, phase shifters, absorbers and circulators. Many methods have been introduced up to now for the implementation of isolators and circulators, which have led to the construction of devices with different dimensions and characteristics . Waveguide structures whose cross section is partially filled with...