Sharif Digital Repository

Examining composite quantum systems through quantum thermodynamics, we face the new concept of binding energy. In this thesis, we are going to present a general definition for binding energy in quantum systems which covers any kind of interactions. First of all, we examine the possibility of energy exchange in a quantum system using quantum thermodynamics. In this theory, energy exchanges of an open quantum system may be divided in to two portions: heat and work; due to an accepted definition, heat is the portion of energy that is supposed to change entropy, while work has no influence on that. In this research, we restrict our calculations to the systems which are thermally closed and... 

The inlet duct is one of the most important components of the waterjet propulsion system, whose hydrodynamic performance is directly related to the capabilities and efficiency of the waterjet propulsion system. In this study, a procedure was proposed to improve the hydrodynamic performance of an inlet duct. According to this proposed procedure, first the basic intake duct geometry of the waterjet propulsion system was prepared using visual programming to simplify the repetition of the design in Rhino design software, and then the numerical analysis of the designed geometry in Star CCM+ commercial software was performed. The simulation results were validated with the results of an... 

Today, due to the scarcity of fossil energy resources, security of energy supply, and increasing environmental concerns, we need to develop new technologies to promote energy-saving and reduce greenhouse gas emissions. One of the suitable options for this purpose is to use the simultaneous production of electric power, cooling, and heating. Meanwhile, trigeneration systems that provide part of their energy needs from the sun, due to the free solar energy source and low environmental impact, can be an ideal technology for clean and safe scattered production. The present study has suggested a trigeneration system of cooling, heating, and power generation based on the organic Rankin cycle and... 

Modern sensors consist of arrays of detectors specially arranged to enhance precision, capabilities, and field of view (FOV). Sensor arrays can have multiple functionalities such as the simultaneous detection of position and motion. We use a linear sensor model and develop an optimization method to design an array of photodiodes. Our objective function minimizes bias and variance estimations. We introduce a maximum likelihood technique to approximate and determine the bias caused by measurement errors, and verify our theory by statistically complete simulations. We apply our theory to design an optimal sun sensor. The sensor has a predefined conical FOV, and its accuracy is controlled by a... 

Condensation from a gaseous phase is a common method for the fabrication of metallic nanoparticles. Electromagnetic induction furnaces are the most common equipment used for this method. Since the sample doesn’t touch any foreign object, this method is one of very few ways to synthesize ultrapure nanoparticles. However, a major setback of this method is its low production rate.One of the only workarounds to this issue is to increase the melt’s surface area so as to present a larger surface for evaporation. In the common setup for this furnace the molten sample takes on a spherical shape which unfortunately holds the lowest surface to volume ration of any shape. The endeavor in this study has... 

Magnetic steering of continuum robots is a promising technology that uses a magnetic field to control the robot without contact and can improve the accessibility, safety, and accuracy of the robot. On the other hand, magnetic localization can also be used as a positioning method without direct line of sight in various applications. Common magnetic localization methods face the challenge of dependence on initial guess, divergence, and high computational cost. In this research, by eliminating the unknowns related to the orientation and rewriting the equations, a new method for magnetic localization has been presented. The advantage of the new method in convergence and increasing the speed of... 

Increasing demand of bandwidth in wireless communications systems led to excessive congestion in frequency spectrum. Since radio spectrum is an expensive and rare source, its efcient use is an important challenge. These limitations as well as increasing number of communications service users,necessitate the use of newer technologies that work efciently with numerous users. Device-to-Device (D2D) communications, full-duplex capability and cognitive radio systems are introduced for this reason. In the previous technologies, due to excessive self-interference (SI), full-duplex transmission has not been implemented. However nowadays technology allows self-interference to be attenuated up to 100... 

Diffuse tensor imaging or tractography is a useful method for tracking the axonal tracts pathways within the brain white matter by monitoring the movements of water molecules along the axons. The higher the level of the tissue anisotropy, the more accurate the pathways can be estimated. But in the swelling regions around an edematous tumor, the excess of watery fluid disrupts the directional movement of water molecules, and consequently, the diffuse tensor imaging is unable to track the pathways. This impairment should be resolved by predicting the axontal tracts arrangement in the blind regions of the images using the numerical modeling. To this end, a finite element model of the human... 

In this research, start-up, performance and stability of a A2O system (Anaerobic/ Anoxic/ Oxic) combined with a Moving Bed Bio Reactor (MBBR), using Kaldnes packings, have been investigated in treating synthetic dairy wastewater. Also the effect of influent Chemical Oxygen Demand (COD), Hydroulic Retention Time (HRT) and Ruturn Activated Sludge (RAS) ratio on removing pollutants such as COD, Total Nitrogen and Total Phosphorous have been studied. The experiments have been designed using ‘Design Of Experiments’ software, and at the end the results have been optimized based on desired terms. The performance and capability of the reactor in removing pollutants in 8, 12 and 16 hours of HRT,... 

For several years, self-organizing networks have been introduced by 3GPP to reduce the costs of mobile operators. Self-organizing networks, by introducing a kind of intelligence to the mobile network, will cause optimal performance and, as a result, reduce the operating costs of operators. Improving network coverage and increasing user data rates are always among the priorities of operators to increase profits and customer satisfaction. Coverage and capacity optimization is one of the most important functions introduced in self-organized networks. In this study, in addition to the coverage and capacity optimization function, the load balance optimization and the contradictory interaction of... 

Due to the growth of energy consumption the use of new technologies and efficient energy conversion is necessary. An example of efficient energy conversion technology is CCHP (Combined Cooling, Heating and Power). The aim of the present research work is to develop a model that could be applied for optimal design of a hybrid CCHP system which would be Solar Combined Cooling, Heating and Power (SCCHP). In order to do so,microturbine power system, cooling and heating equipment’s such as absorption system and heat exchanger and also solar collector have been considered as an integral part of the system. The objective of the application of the model has been to identify proper sizing of all... 

Reservoir lifetime optimization is an important issue. The policies that are used for maximum production using optimization methods become challenging in the presence of uncertainty. Robust Optimization (RO) method is a technique to deal with uncertainty. Because of insufficient data, uncertainty is an inherent characteristic of reservoir model. This leads to inexact solutions of an optimization problem. Also, design based on uncertainty in economic parameters, especially uncertain oil price is a challenging issue. Taking the uncertainty explicitly is a solution when there is no measurement available. To take into account uncertainty several possible values (realizations) for the uncertainty... 

People are increasingly using private vehicles as a result of the ever-increasing population growth worldwide and the increasing number of travel requests through the transportation network. There are many problems associated with the use of private vehicles on the transportation network, including traffic congestion and air pollution. To address the existing demand, decision-makers have always sought effective modes to respond to the existing situation. For passengers, the proposed modes of transportation should offer the same level of convenience and affordability as a private vehicle. In recent years, shared mobility has become increasingly popular. This mode of transportation has... 

In this thesis design and simulation of SMB for four different mixture was done with Aspen chromatography package. Simulation for three mixtures of D-Psicose and D-Fructose, racemic mixture of Bupivacaine and Ibuprofen racemate were done with the aim of validation, based on experimental data of articles. The simulation results matched well with the experimental results in articles. The separation of p-xylene from mixed C8 aromatics and Para Diethyl benzene (as desorbent), was simulated for one of the p-xylene producing units and results were validated against the PFD. The influence of various parameters on the purity and recovery of p-xylene were investigated. The studies showed high... 

In this study, redundancy allocation problem for a system with y subsystem including k-out-of-n structure is investigated. Due to existing repairable components in each subsystem, the model consists of selecting number of repairman and redundancy level for each subsystem. The model is constructed based on Markovian process and the goal is maximization of steady-state availability under constraints such as cost, weight, and volume. In this model, two type of costs are considered; cost of employing repairmen and cost of preparing components and decision variables of the model are number of repairman and number of component in each subsystem.The model is located into integer non-linear... 

Joint price and service capacity decisions and integrated pricing and queuing problems with finite or infinite buffers are two remarkable issues of pricing research. In this thesis we consider a joint price and service capacity determination problem in a single server, finite buffer queuing system. Customers arrival and serving occur as Poisson processes. Because of finite buffer capacity, customers finding the system full upon their arrival would be rejected. Customers differ with respect to their reservation prices and time sensitivities. This study focuses on investigating the effect of finite buffer capacity and customers reservation prices and time sensitivities on optimal policy and... 

Quadcopters are a bunch of vertical takeoff and landing UAVs and generally consist of four symmetric arms, each possessing a rotor-blade at the end. Quadcopters are able to retain their state and position by performing static maneuverability. Conventional quadcopters have less actuators (four engines) than their DOF (six degrees of freedom in the space). Thus, it is impossible to control all DOF of the system independently. Nevertheless, one can make a solution to this problem by increasing the number of actuators, so that each rotor-blade can also rotate about the corresponding arm. Such a quadcopter is so called a “tilt-rotor quadcopter”. The aim of this work is to model a tilt-rotor... 

Wind energy, as a type of renewable energy resource, is clean and is rapidly growing globally. The intermittency in the production of wind energy is the most major obstacle for these producers in a competitive electricity market, to compete with thermal units. Most existing models in the literature mitigate the risk of wind power, by coordinating them with energy storages such as pumped storages power plant. Here, in this thesis, another risk mitigation approach is introduced which combines wind energy and natural gas power plant in an electricity market. In addition, as the penetration level of wind power grows, the wind power producers must be considered as a price-maker player which their... 

This research is focused on optimization of empty freight railcars circulation by assuming cooperation among shipping companies. The objectives are twofold: first, to develop an efficient and effective model which can provide a useful management tool to improve freight car utilization for shipping companies; second, to show the advantages of Horizontal Logistics Cooperation (HLC).Two formulations have been developed for the empty railcar distribution problem, both seeking to find how railcars move not only at the lowest possible cost but also at the lowest possible delays under supply limitation and demand satisfaction. The problem is first formulated as a single-commodity network flow model... 

In recent years, economy globalization has led to a major focus on the needs of customers, Moreover globalization has resulted in geographically distributed suppliers across the globe. In such a space, using cloud manufacturing as one of the novel technologies in manufacturing that deals with resource management has been more and more taken into consideration. one of the most important issues in cloud manufacturing is service composition, in which, after receiving customer’s demand, a combination of cloud services is provided to meet customer’s demand. In fact, the customer's need is decomposed in different tasks, each of which is carried out by one (or more) manufacturing plant. the purpose...