Sharif Digital Repository

In two past decades, a revolution has occurred by emerging of substation automation system in field of substation control and protection system. The traditional control system has changed to the modern automation systems which are based on computer networks. The development of this project become possible by having experience in and being familiar with automation systems, studying equipment specifications, tasks, and criteria and analyzing operation of various systems. The main target of this thesis is evaluating the automation system precisely and exhaustively and developing a model based on mathematical relations. This model is founded based on the application and analysis of the networks.... 

According to power limitation on a chip and the need to simultaneously access high utilization and low power consumption, Multi-Processor System-on-Chip (MPSoC) architectures have been introduced. The major part of power consumption in a network on chip belongs to interconnects. One of the most important issues is to decrease power consumption while maintaining high utilization. The ability of optical interconnects in decreasing power consumption and increasing utilization has introduced a new architecture called optical network on chip. This architecture uses the benefits of optical signals and elements in order to transfer data. In this thesis, we introduce a new architecture with... 

One of the most common methods of producing fullerenes is electric arc vaporization of graphite. Due to the low yield and purity of the nanoparticles in this method, the synthesis and isolation of the area research is important. In this work, the production was improved in a multi-channel arc reactor in which having horizontal graphite electrodes. The influence of various operational parameters such as pressure of inert gas, spark time, interval time between two sparks, voltage and current were completely optimized. Moreover, the prominent advantage of the new reactor was increasing the number of manufacturing units, at least from one to three, which the production of fullerene was... 

For over a hundred years, vehicles have entered the human environment and influenced it. One of the most important effects that vehicles have on their surroundings and humans is their acoustic noise. The gearbox is one of the important components of the vehicle's transmission chain, in which the gears interact with each other and cause to create noise and vibration. These vibrations are transmitted through the bearings to the gearbox casing and then transferred to other parts of the vehicle via gearbox supports. Many researchers have studied the factors of NVH production in gearboxes and used methods such as gear profile modification and optimization of shaft and casing to reduce NVH. This... 

Nowadays oil and gas industry has taken the pulse of world energy. Different countries of the world are trying more and more to explore and produce this black gold. To do so these countries has gained many experiences and even gone to seas and oceans to find oil and gas. In the process, they has faced with a new phenomenon called gas hydrate. The phenomenon which was unknown and destructive at first after excessive research, today is even called as the future energy source of the world. But what we discussed in this study is hydrate as a problem in oil and gas industry. Gas hydrates are formed in favorable temperature and pressure condition (low temperature and high pressure) in the... 

The number of transistors on a single chip is growing exponentially which results in a huge increase in consumed power and temperature. Parallel processing is a solution which concentrates on increasing the number of cores instead of improving single thread performance. Graphics Processing Units (GPUs) are parallel accelerators which are categorized as manycore systems. However, recent research shows that their consumed power and energy are increasing. In this research, we aim to propose methods to make GPGPUs energy effiecient. In this regard, we evaluated the detailed consummed power of GPGPUs. Our results show that memory sub-system is a critical bottelneck in terms of performance and... 

The main objective of this project is the deposition of photo-catalysts on cement and concrete blocks with an emphasis on commercialization. We started with an extensive study of common methods introduced in previous literature, and conclude with a number of suggestions for industrialization. First, slurry and sol-gel deposition of the photo-catalysts on blocks of type 2 commercial cement which is one of the most used materials in construction of buildings and waste-water treatment plants has been examined to reach a method of sample formation. Due to the simplicity of common methods and low quality of formed samples (less than 5 percent aging efficiency), the obtained experience was used to...