Sharif Digital Repository

The goal of this project, has been designing a downhole camera, which captures images from environment of a well and transmits that to the surface. High temperature and pressure of well environment and corrosion and limitation in data transmission rate which is because of mono conductor cable, are the challenges of designing this system. For doing that, first, the principles of image compression are explained. Then, based on that, an image compression system based on wavelet transform has been designed. Its components are examined too. For making the introduced system resistant to the high pressure and temperature, using an isolated case is suggested. For implementation, an... 

Today, one of the most important concerns of oil and gas wells is to increase the efficiency of wells. To increase efficiency, well integrity must be monitored. One of the factors that destroy the integrity of the well is the creation of hydraulic fractures inside the oil and gas wells, which is one of the main factors that reduce the efficiency of the well. Hydraulic fractures cause water, gas and other materials to leak into the well or oil and gas to leak out of the fracture, which in both cases reduces the efficiency of the well. One of the most important technologies for identifying hydraulic fractures is the use of SNL tools from oil and gas wells. The oil and gas well SNL tool listens... 

Sonic and ultrasonic measurements are used for checking status of wells. Well logging is used to estimate well specifications like borehole diameter, casing thickness, cement bond quality and cement sheath thickness. In this thesis, some reported works in field of sonic/ultrasonic measurement of oil wells are reviewed and results of software implementation of ultrasonic measurement with pitch-catch arrangement, pulse-echo arrangement and phased array arrangement are presented. ultrasonic measurement with pitch-catch arrangement uses one transducer for transmitting ultrasonic waves and two transducers (in different distances) for receiving ultrasonic waves. Ultrasonic measurement with... 

Production logging consists of running measurement instruments called logging tools into an oil or gas well to measure various parameters such as temperature, flow velocity, pressure, density, etc. The primary purpose for production logging is to allow enhancing production profits and decreasing costs. Nowadays the common way for fluid density measurement as a part of these tools depends on radioactive source. Special considerations must be taken upon the use of this principle due to its radioactive character. This thesis is focused on a non-radioactive method of determining density. The subject of this thesis is to consider methods for measuring density based on principle of acoustic... 

Most of the time there are three different materials in oil wells; Oil, water and gas. Measuring volume percentage and flow of the individual materials (phases) is an important issue, due to their critical role in extraction process control. Measuring tool should be able to measure flow and percentage of each phase in a case that they are separated (in deviated wells due to gravity). In addition, the measurement should be carried on in a high temperature and high pressure environment and in presence of corrosive substances. Most of previous researches on Multi-Phase Flow Meter (or MPFM) led to mechanical methods to measure flow and they usually use electrical impedance or permittivity for... 

Emotion recognition from speech signals has become one of the most popular researches in recent years. In order to increase human-machine interaction, a proper connection must be established between them. To achieve this goal, a machine must be able to understand the situation and respond accordingly. Part of this process involves understanding the user's emotional state. In recent years, various methods have been proposed to increase the efficiency of the speech emotion recognition system. These methods include collecting various audio databases, extracting efficient features from speech signals, using feature selection algorithms, designing different classifiers, as well as combining... 

Once a well has been drilled before it is cased with the steels (open-hole well), some logging must be done to record information’s about layers, geologic formations, geophysical and petrophysical properties of well. All the information’s that gathered from sensors and tools transmitted to the surface by a down-hole modem. This information is corrupted during the transmission by the communication channel. The most notable influence of this channel is noise, attenuation and interference between successive data bits. On the other hand, the characteristic of channel changes with the length of the cable, temperature, connections and so on. So using a set of fixed filters is not effective. The... 

Automatic traffic incident detection is one of the most important areas in intelligent transportation systems. In recent years big cities have faced major problems with traffic flow and congestion. Therefore, real time traffic monitoring in order to analyze traffic flow plays a key role in solving traffic problems. The purpose of this study is to design an integrated system for automatic traffic incident detection and traffic monitoring based on deep learning with vehicle detection and classification, counting, average speed estimation, extracting traffic parameters such as congestion level and event detection such as unauthorized stops and deviation from the path. In this research, a... 

Nowadays, lithium-ion batteries are widely used in electric vehicles due to their higher energy density and longer life cycle compared to other storage systems. However, safety concerns about catastrophic risks like fires exist, caused by thermal runaway in lithium-ion batteries. This study aims to provide an accurate electrochemical thermal model for predicting the phenomenon of thermal runaway. In recent years, researchers have conducted many numerical models that generally estimate input parameters. Accurate modeling of thermal runaway is challenging due to the wide range of physical properties and conditions. Therefore, understanding the importance of uncertainty in input parameters,... 

Wind power is site dependent and is by nature partially dispatchable. Furthermore, good wind sites are far from grid. Due to these problems, and along with the existing limitations in the transmission networks, a comprehensive analysis over an extended time is needed to properly explore all potential wind sites for wind capacity allocation. This problem is computationally expensive and decomposition methods are required to break down this problem. Here Benders decomposition approach is used, which is a popular technique for solving large-scale problems, to decompose the original problem into a master and a subproblem. The master problem is a linear problem, which allocates wind capacity to... 

Single nucleotide polymorphs, There are changes caused by a mutation in a nucleotide in the Dena sequence. Mononucleotide polymorphisms are the most common type of genetic variation. Some of these changes have little or no effect on cells, while others cause significant changes in the expression of cell genes that can lead to disease or resistance to certain diseases. Because of the importance of these changes and their effect on cell function, the relationships between these changes are also important. Over the past decade, thousands of single disease-related mononucleotide polymorphisms have been identified in genome-related studies. Studies in this field have shown that the expression of... 

In the past few years, many research works on the controllable integration of metal nanoparticles and metal-organic frameworks were done, since the obtained composite material shows a synergism effect in catalysis and photocatalysis, drug delivery applications, gas, and energy storage, as well as sensing. For the first time, in this study, we employed template-assisted growth to synthesize Au-HKUST-1 Nanocomposite. XRD analysis entirely confirms that employing this strategy in synthesizing Au-HKUST-1 was wholly successful, and the plasmonic properties of this nanostructure were studied via UV-visible spectroscopy. In the course of synthesis, gold nanoparticles with 70nm diameter were... 

Age-related macular degeneration (AMD) is the most common cause of vision loss in those aged over 50. There are two main types of AMD, Wet and Dry form. Wet AMD is more severe though more treatable. There are three conventional treatments for AMD including laser therapy, surgery and intravitreal injection of anti-VEGF into the eye. Delivery of drugs to the posterior segment of the eye is still challenging and several implants and devices are currently under investigation for their ability to stimulate the retina, producing visual percepts. The application of intravitreal bevacizumab (Avastin) has expanded tremendously from the time of its introduction into ophthalmic care since 3 years ago....