Sharif Digital Repository

In this piece of work, a gravity model is suggested as Iranian non-fuel export model to OIC countries. The most important results out of this model are the acquired coefficients of two variables, namely “ECO membership” and “Economic and Trade Freedom of Importer”. At first, we expected that for importer, being a member of ECO would increase the amount of trade with iran. Surprisingly, this is not what we see in a model. In fact, as ECO has not achieved any tangible success in increasing trade between its members, eastern Asian Muslim countries has become an important trade partner for iranians. This result is compatible with other pieces of researches about ECO. “Economic and Trade Freedom... 

Synthesis gas is a gaseous mixture which mainly consists of carbon monoxide and hydrogen. Different methods are used to produce synthesis gas but the most important method is auto thermal reforming. This method is based upon catalytic reactions. Steam, oxygen and natural gas are the influents to the reactor and synthesis gas will be the effluent. Ni catalysts on alpha-alumina as the support media are usually used in this process. These catalysts are highly heat resistant and insure great qualifications for reactions. This thesis tries to find best solutions of synthesis gas production suitable for feeding to a methanol production unit. There are four main reactions. Three of which are highly... 

This thesis revisits the effect of dynamic soil-structure interaction (SSI) on multistory buildings with a probabilistic approach. For this purpose, the relationship between the strength demands of fixed- and flexible-base multi-degree-of-freedom (MDOF) systems, or strength reduction factor thereof, with that of fixed- and flexible-base equivalent single-degree-of-freedom (eSDOF) systems is investigated considering prevailing uncertainties. To this end, Monte Carlo sampling analysis is employed in which a suite of nearly 2000 records are utilized to properly quantify the ground motion uncertainty. The soil-structure system is modeled by the sub-structure method. The uncertainty in the... 

Silver nanoparticles are widely used in different industries because of their antibacterial effects. Many synthesis methods were used to obtain silver nanoparticles. In this study the microwave method is used to synthesize nanosilver. This method is easier and faster in comparison to other methods. The effect of precursors’ concentrations, using different solvents, different remaining time in microwave and microwave power were studied. By increasing the reaction time, microwave power and using different solvents, nanosilver particle size varies from 2 nm up to 300nm. The TEM images, size distribution, XRD patterns and UV-visible spectrum are shown. The obtained nanosilver was used to observe... 

This paper presents an integrated attitude control and estimation of satellite by using adaptive neural fuzzy (ANFIS) logic, indeed a system which using ANFIS controller and estimator is considered then an ANFIS simulator that can control and estimate contemporary is supposed. ANFIS system has been trained by using data obtained from an optimal PID controller. Then ANFIS controller performance has been compared with the performance of a PID controller, the analogy has repeated in different situations such as noise and uncertainty. Results show that system with ANFIS controller is more optimal than PID’s in all these situations. After that ANFIS estimator is studied and results indicate the... 

In this research, synthesis and characterization of photocatalytic properties of g-C3N4 / TiO2 nanocomposite was carried out. The target of research was to increase the photocatalytic properties of g-C3N4. So at first, g-C3N4 was synthesized from melamine precursor via thermal pyrolysis. Then, TiO2 nanoparticles were synthesized via sol – gel method. g-C3N4 / TiO2 nanocomposite with heterojunction structure was synthesized in one step by thermal pyrolysis of certain amounts of melamine precursor and TiO2 nanoparticles mixture in 550 ℃. Characterization of synthesized samples was carried out by XRD, FT-IR, UV-Vis, PL, BET, DLS and FE-SEM tests. Characterization results showed that g-C3N4,... 

Due to its higher degrees of freedom in comparison with a Single-Input Single-Output (SISO) radar , a Multiple-Input Multiple-Output (MIMO) radar has superior resolution , higher accuracy in detection and estimation , and more flexibility in beamforming . As there are multiple receivers in a MIMO radar system , if we can reduce the sampling rate and send fewer samples to the common processing center , the cost can significantly be reduced . Sometimes , the problem is not even the cost . It is the technology issues of high sampling rates . The reduction in sampling rate can be achieved using Compressive Sensing (CS) or in a much simpler form Random Sampling (RS) . In CS , we take...