Sharif Digital Repository

In the oil industry, a better understanding of the well condition leads to improve the management and increase the oil production. Production logging tools is a set of tools for measuring different parameters such as density, diameter and flow in oil and gas wells. These tools are considered among high-tech tools in the oil industry. The reason is that they should work in harsh conditions, i.e. high temperature about 170 ° C and pressure around 15000 psi, and at the same time give an accurate measurement of the quantity. Current production-logging tools measure the fluid velocity and the diameter of an oil well by individual mechanical tools, and the density by a radioactive densitometer. ... 

Detection and Tracking objects in various environmental conditions is a challenging task in computer vision. Abrupt changes in illumination, object size and noise level make this task even harder. Due to these problems, it is somehow impossible to propose a fully functional system for tracking every type of object. In this thesis we propose a new method for detection and tracking vehicles in traffic scenes. The problem is solved by dividing it into two parts: at First we have evaluated more than ten state-of-the art trackers, the final multi-vehicle tracker is chosen, and then, like any other object tracking method, we have used a unique identiy for each vehicle. This traffic identity is... 

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... 

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... 

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... 

Reinforced concrete is one of the most important structural materials used in the construction industry worldwide. Nevertheless, certain physical and chemical factors in the service environment can contribute to its deterioration and failure. One of the most significant factors is the reinforcing steel bar (rebar) corrosion. In order to minimize the rebars corrosion, different kinds of coatings were investigated and evaluated by scientists. In this investigation comparative studies were performed on two different kinds of coated rebars (zinc-rich epoxy and polyamide epoxy coated rebars) and uncoated rebar. In order to evaluate these reinforced concretes, the adhesion, durability, thickness... 

In this thesis, a model is presented to detect and monitor the rotor bar's condition of large motors. This proposed model uses two diagnostic methods MCSA and ZCT, to extract the fault components. The input of the proposed model is only the motor current at two levels of 80% and 100% of the nominal motor load, which by using the two methods MCSA and ZCT and making changes in how to use them can be the disadvantages of other methods such as incorrect detection of rotor bars in Large motors with variable load, the harmonical stator voltage (or the presence of the drives) and asymmetric conditions. The extracted components are classified using two learnable algorithms, the k-NN algorithm and... 

The problem of joint design of transmit code and receive filter is considered in many application scenarios of multiple input multiple output (MIMO) radar systems. The performance of the joint design problem is evaluated with the signal-to-interference ratio (SINR) metric in the presence of noise. In such problems, the optimization problem is to maximize SINR on the receiver side with the constraints that are applied on the transmitted waveform. Our proposed method, RTR, is a manifold-based geometric method that performs better than the SDP method in terms of algorithm execution speed and calculation complexity. For simulation, we took sampled and real TIR with Target Aspect Angle (TAA) in a... 

This study aimed to investigate the efficiency of machine learning algorithms in capturing the dynamics of water particles' age distribution and in estimating the time series of median travel time (MTT) in river basins. The mechanism of solute transport in a catchment does not follow the hydrograph shape of the catchment and depends on the spatial and temporal distribution of solute resident time. The equations governing the age dynamics of water particles discharged from a catchment have been presented analytically in recent research. These equations showed that the transfer of solutes depends on various factors, including climatic conditions, basin topography, and basin vegetation. Also,... 

Photocatalytic degradation is one of the developing modern and effective methods for decontamination of hazardous pollutants of chemical industrial wastewater. In spite of great developments in this field of research and its various advantages, finding a process with high efficiency and optimization of the operating parameters are still required to be investigated. In this study, the photocatalytic degradation of 2-Nitrophenol under natural sunlight irradiation using industrial photocatalysts such as TiO2 (Hombikat), ZnO, WO3 and TiO2 (P25) was investigated. The photocatalysts were characterized by the XRD, BET, SEM and DRS tests and the effects of significant operating parameters (the... 

Performance of a multi tube pulse detonation engine has been investigated experimentally. A pulse detonation engine uses detonation phenomena and simply consists of a large narrow tube which has closed head, and has feeding system and ignition system. In this tube, detonation is produced periodically to generate thrust. In multi-tube mode, several tubes are arranged in parallel which detonate sequentially. Our PDE consists of 2 tubes with 70 cm length and 25 mm inner diameter which have several places performed for high speed pressure sensors installation. The premixed hydrogen-oxygen mixture are controlled by solenoid valve and injected on head-end and ignited by conventional spark plug.... 

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... 

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...