Sharif Digital Repository

Design methods and technologies for the implementation of earthquake-resistant buildings in recent years has made remarkable progress. The control and energy dissipation systems such as seismic isolation systems in buildings, according to their history hands-on experience in the world, have shown good performance against seismic hazards, hence they have been considered by scientists and engineers. Most of the energy dissipation systems have limitations such as service life,durability, maintenance , need to change and modifying the structure geometry after the earthquake. In recent years the use of shape memory alloys to improve the behavior of base isolation is considered. Shape memory... 

Today, building sectors account for 34% of total energy consumption in Iran. Increasing demand of the comfort level along with population growth necessitates much more attention about energy requirements in the country. Such phenomenon has already raised concerns about the heavy environmental impacts. The present research studies minimization of global warming potential effect for an educational building by developing life cycle optimization model. The Department of Engineering of Sharif University of Technology is selected as the case study and optimal solutions has been achieved for this building. Results state that implementing cogeneration and renewable energies can reduce20 -25% of the... 

The Brushless Doubly-Fed Machine (BDFM) is a machine which incorporates the robustness of the squirrel cage induction machine and the speed and power factor control of a synchronous machine. All of these advantages are obtainable from a relatively low rating power electronic converter (e.g. 30 % of the machine’s rating). The stator of a BDFM is furnished with two balanced three phase windings of conventional design (power and control winding). These windings differ in pole number and are often excited at different frequencies. Hence, there is no direct magnetic coupling between them. The power winding is connected to a constant-voltage, constant-frequency source and the control winding is... 

In this thesis, concerning Eigenstrain Theory, the micromechanical formulation of dental implants has been derived for the first time in the fields of Mechanics and Medical Science. The proliferation of using dental implants as a prosthesis for the people who lost their teeth because of poor maintenance and smoking cigarette results in scientists think more about the design of these implants and their stress fields inside the mandible. It is crystal clear that these stress fields cause stress shielding, which is a phenomenon that brings about bone loss or decrement in the bone density. Hence, if we know the stress that is produced by the implants inside the mandible, we can optimize the... 

In the recent years, nanophotocatalytic process for E. coli inactivation has become considerable choice for water treatment. Having suitable catalytic characterizations, nanophotocatalysis could be considered as an alternative to current E. coli disinfections methods.
In this study, antibacterial effect of Fe-Cd/TiO2 (TiO2 doped with Fe and Cd) under visible light was reported for the first time. The Results show that by comparing Fe-Cd/TiO2 with commercial TiO2 (P25 Degussa), bactericidal efficiency of this codoped photocatalysis under visible light is high and effective. Indeed, Nanoparticle of Fe-Cd/TiO2 disinfects E. coli (cell density: 107 CFU/ml) almost completely within 55 min... 

Observation made after previous earthquakes revealed that irregular structures had shown unfavourable performance compared to their regular counterparts. In general, structural irregularities are classified into two categories, “irregularity in plan,” and “irregularity in elevation (height).” In order to investigate the effects of irregularities on the “response modification factor,” three types of 3-D steel structures were studied, namely type 1: regular ones, type 2: split-level ones (having irregularity in elevation), and type 3: irregular in plan as a result of having eccentricities of 5%, 10%, and 20% between the centers of mass and rigidity. All the studied frames were initially loaded... 

By using of raw measurements of GPS receivers including carrier phase and Doppler frequency we can estimate attitude parameters of a platform on which the receivers are installed in a proper orientation. In this research attitude parameters are estimated based on quaternions. To this end a discrete Kalman filter was designed to predict the attitude parameters by using of carrier phase double difference measurements and then update the predicted parameters by using of Doppler frequency double difference measurements. Doppler frequency measurements were used to estimate the quaternion rates which are used in update step of Kalman filter algorithm. A robust algorithm for carrier phase ambiguity... 

Conventional eccentric braced frames often sustain large residual deformations and significant damages after strong earthquakes which may lead to heavy damages or even destruction of the structure. Here, a self-centering, Y-inverted, eccentrically braced frame (SC-YEBF) is proposed which combines the lateral load resisting benefits of YEBF including strength, stiffness and energy dissipation capacity with the re-centering capacity of post-tensioned (PT) high strength steel strands used at beam-to-column connections. A design procedure is presented assuming that all the seismic input energy is dissipated through inherent damping and plastic deformations of the link-beams. Thus, in the... 

Today, the world energy crisis, the need to optimize its consumption and discussion to reduce fuel consumption has become a vital issue. The conventional vehicle air conditioning system due to compressor in refrigeration cycle, which has causes a severe loss in engine useful power, increasing fuel consumption, etc. Therefore, the main goal of this project is the feasibility of the vehicle cooler replacement with the vapor jet refrigeration cycle. In this cycle, the energy required for completing the refrigeration cycle is provided from the heat of the water inside the radiator that is possible with conventional refrigeration cycle. The first stage of this project includes design and... 

In this essay we study the concepts of nuclearity in C-algebras, and amenability in Banach algebras. A proof on the "every amenable C-algebra is nuclear" is studied. A Banach algebra A is called amenable if every continous derivation D : A ! E , is inner i.e. there exists anif in this denition E is a dual Banach A-module and norm continuity replace by w-continuity then we have Connes-amenability; Connes-amenability was rst considered for von Neumann algebras in [J-K-R] (and thus should perhaps be called Johnson-Kadison-Ringrose amenability). The reason why this notion of amenability is usually associated with A. Connes are his papers [Conn 1] and [Conn 2] The name "Connes-amenability" seems... 

In the present study, a simple synthesis route was used to obtain Titanium dioxide nanoparticles with aggregates different in size. The purpose was to study the effect of TiO2 nanoparticles size on photocatalytic activity and develop it to sonocatalytic properties. Surface modification with polymeric and/or anionic agents were carried out to stabilize titania nanoparticles in aqueous media with neutral pH, specifically in SBF. Sonocatalytic properties of modified and bare particles were compared to show if the particles may be used in future studies on sonodynamic therapy. Results showed that increment in size of the aggregates, similar to primary particles, lead to lower properties due to...