Sharif Digital Repository

During the last few years, utilization of distributed generation (DG) in power systems has been widely increased. This trend has magnified studying the effects and impacts of DG on such systems. One of the benefits of DGs in a power system is loss reduction. If determining DG size and place is done properly, the loss of the network can be minimized. Another way of reducing loss in distribution network is by reconfiguring the network. During the reconfiguration, constraints like being radial, avoiding load isolation as well as voltage/current limitations must be taken into consideration. Taking these constraints into account makes reconfiguration an optimization problem. In this project, the... 

Electrical and magnetic thin films have attracted many researchers’ attentions in random access memories, sensors, actuators and Nano electronic systems industries in recent years. Recent tendencies on decreasing the dimensions of the electronic equipment generate important investigations on coupling the electrical and magnetic properties. In this way multiferroic material as it has these two properties and has a significant between other similar materials, attracted much attention of researchers. So in this research at the first step, it has proceeded to make a multiferroc composite with depositing of barium titanate and strontium hegzaferrite by pulsed laser depositions and for decreasing... 

In this research the microstructural, electrical and optical properties of Strontium Titanate and Barium Strontium Titante thin films, fabricated through Pulsed Laser Deposition (PLD), were investigated. X-ray Photoelectron Spectroscopy and X-ray Diffraction study showed that the stoichiometry of the target material was highly preserved by using PLD method. Scanning Electon Microscopy as well as Atomic Force Microscopy depicted that the using of pressed and sintered target is a suitable metod for improving the surface quality of the thin films. Using the pressed target decreased the quality of the thin films and the average roughness of the films increased. The main reason for this... 

Barium Strontium Titanate (BST) thin films are a promising candidate for dielectric capacitors due to their excellent ferroelectric properties. It is well known that BST has a high dielectric constant, low loss tangent, low leakage current and low Curie temperature. Pulse laser deposition (PLD) has been used extensively as it can maintain the stoichiometry of the target in the deposited film and also has high coverage ability, which both are important in capacitors. In this paper, Ba0.6Sr0.4TiO3 (BST) thin film has been deposited on the SiO2/Si substrate by pulsed laser deposition technique. The effect of post-annealed temperature, oxygen pressure deposition ambience and number of pulses on... 

In the present study we examined the fabrication of electrospun polymer drug delivery system for the production of polymeric film containing Rizatriptan drug. Fabricated films were underwent X-ray diffraction and DSC tests to ensure that the drug is not in crystalline and amorphous form. And the results revealed the fact that the drug is fully dispersed in the polymer. pH changes in the aqueous phase is too low so that it enable the polymeric film to be suitable for use in oral administration. In-vitro assay for different combination of sublingual polymeric suggested that Rizatriptan film with 3% weight by volume and 30% by weight by volume of electrospun polymer PVP is the best combination... 

In this research we focus on synthesis and analysis of metal and metal oxide nanoparticles and their photocatalytic activity. At the beginning a high current DC power supply and a reactor for the electrical arc discharge process designed and implemented. Several nanoparticles such as tungsten oxide, zinc oxide, silver and gold have synthesized by this method in deionized water, deionized water including surfactants and stabilizers and analyzed. Several characterization techniques such as X-ray diffraction (XRD), dynamic light scattering (DLS) X-ray photoelectron spectroscopy (XPS), BET, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis spectroscopy have... 

DNA microarrays consist of DNA microscopic points that are attached to a solid surface such as glass, plastic or silicon chip and formed as an array. The fixed pieces of DNA are considered as searchers. In an experiment, we can use thousands of searchers. Therefore, any microarray consists of the same number of genetic tests as the experiment performed on all of them in parallel. Whit this ability, arrays have speeded up the biological investigations. Microarray technology can be seen as a continued development of southern blotting. However, the most important stage in this technology, analysis of data, requires reliable bioinformatics tools achieving high reliabilities. Infectious diseases,... 

Photonic lattices can provide an inexpensive and fine tools to investigate some common phenomena in condensed matter physics, quantum optics, relativistic mechanics,atomic and molecular physics. These phenomena contain Anderson localization,Bloch oscillation, Dynamic localization, coherent and squeezed states, Relativistic Dirac equation, Rabi oscillation, ... .In this thesis, it was investigated three worthy phenomena of them, which at first are introduced in condensed matter physics for electronic systems, in photonic lattices. These phenomena are as follow: Transverse localization of light wave, Bloch oscillation and dynamic localization of light. It was also simulate classically, the... 

In this thesis, we want to present methods that are able to solve the assignment tasks problem in a heterogeneous computing system. These methods are two hybrid methods that are constructed by composing Hopefield Neural Networks with Genetic Algorithms and the Simulated Annealing. First, we solve the relaxed problem by applying Genetic Algorithms and the Simulated Annealing and we compare the results of these ways with other traditional methods. Then, we solve the constrained problem with mentioned hybrid methods. The definition of the problem is as following: Consider a distributed computing system which is comprised of set of processors with different speeds but the same structure. We want...