Theoretical and Experimental Investigations of Turbocharger Matching on a Naturally Aspirated Diesel Engine

, M.Sc. Thesis Sharif University of Technology Shams Derakhshan, Mohamad Amin (Author) ; Hajilouy Benisi, Ali (Supervisor)

Abstract

Diesel engines have widely used in past hundred years. During this time costly and extensive researches have been done to improve engine performance, which is going on. Important issues of these engines are higher specific power and efficiency and lower specific fuel consumption and pollutions formation. One of the best methods for engine performance improvement is matching a convenient turbocharger on engine. A turbocharger increases the engine air mass flow rate by increasing the inlet pressure and density. Due to increase of fresh air mass flow rate, fuel mass flow rate and power would increase. The aim of this research is to choose the convenient turbocharger for the OM355 naturally...

Sentiment analysis on stock social media for stock price movement prediction

, Article Engineering Applications of Artificial Intelligence ; Volume 85 , 2019 , Pages 569-578 ; 09521976 (ISSN) Derakhshan, A ; Beigy, H ; Sharif University of Technology

Elsevier Ltd 2019

Abstract

The opinions of other people are an essential piece of information for making informed decisions. With the increase in using the Internet, today the web becomes an excellent source of user's viewpoints in different domains. However, in one hand, the growing volume of opinionated text and on the other hand, complexity caused by contrast in user opinion, makes it almost impossible to read all of these reviews and make an informed decision. These requirements have encouraged a new line of research on mining user reviews, which is called opinion mining. User's viewpoints could change during the time, and this is an important issue for companies. One of the most challenging problems of opinion...

Leakage diagnosis using closed-form solution and linear observer

, Article 5th International Conference on Control, Instrumentation, and Automation, ICCIA 2017, 21 November 2017 through 23 November 2017 ; Volume 2018-January , 2018 , Pages 255-258 ; 9781538621349 (ISBN) Derakhshan, M ; Haeri, M ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2018

Abstract

In this paper, an approach is proposed to estimate the location of leakages in liquid transmission lines with a high accuracy. First, the mathematical model is analyzed and a closedform solution is provided for the partial differential equations of the pipeline. Next, the leakage location is calculated using the closed-form solution. The calculations are applied to various leakages and are extended to a case in which the pressure and flowrate do not converge to constant values. Considering a singleleakage pipeline system, a linear observer is utilized to estimate the leakage location with reduced errors. The simulation results are presented and the proposed method is verified by changing the...

Production of Copper Nanoparticles by Electromagnetic Levitation Melting Method

, M.Sc. Thesis Sharif University of Technology Derakhshan, Rouzbeh (Author) ; Halali, Mohammad (Supervisor)

Abstract

In this research Copper Nanoparticles have been synthesized by electromagnetic levitation gas condensation method which is a novel method for producing fine and pure metallic powders. Copper samples with 2 gr weight were levitated and then melted.the supersaturated vapor above the melted droplet have been cooled exerting pure argon and helium as cooling and carrier medias. To investigate the morphology and particle size of the produced nanoparticles, SEM and DLS analysis have been used and for characterizing the elements exist in the powder ,XRD analysis have been carried out.SEM images and DLS analysis of produced powder showed spherical cooper nanoparticles with narrow size distribution...

Analysing Purchase Satisfaction Using Opinion Mining

, M.Sc. Thesis Sharif University of Technology Derakhshan, Ali (Author) ; Beigy, Hamid (Supervisor)

Abstract

Opinions and experiences of others give us valuable information in making decisions. Recently, with the expansion of using social networks and websites, people can easily share their opinions about miscellaneous things. This huge amount of information cannot be analyzed by individuals, so a system that automatically analyzes opinions is needed. This need invokes new field of research that is called opinion mining. User’s viewpoints could change during the time, and this is an important issue for companies. One of the most challenging sub-problems of opinion mining is model-based opinion mining, which aims to model the generation of words by modeling their probabilities. In this thesis, we...

Experimental Studies for Lactase Immobilization on the Polymer base and Characterising

, M.Sc. Thesis Sharif University of Technology Derakhshan, Elahe (Author) ; Yaghmaei, Soheyla (Supervisor)

Abstract

Immobilization of β-D-galactosidase represents an important approach for development of lactose hydrolysis technology.Chitosan proved to be an excellent carrier for β-Dgalactosidase immobilization, by both covalent binding and sol-gel entrapment combined with adsorption. Among different preparation methods of chitosan support particles for covalent binding, emulsion cross-linking was the most efficient, producing narrow-sized microspheres, without aggregation.The best process parameters of β-D-galactosidase immobilization by covalent coupling on chitosan microspheres were found as 3% glutaraldehyde cross-linker concentration, enzyme loading of 27 mg protein/g dry support, 6 h reaction time,...

Leak Detection and Location in Oil Transmission Lines by Closed Form Solution and Linear Observer

, M.Sc. Thesis Sharif University of Technology Derakhshan, Masoud (Author) ; Haeri, Mohammad (Supervisor)

Abstract

In this paper, an approach is proposed to estimate the location of the leaks in oil pipelines. The pipeline possesses a system of Partial Differential Equations (PDE). First, a closed-form solution is applied to the pipeline equations and the leakage location is found solving the steady-state equations. To tackle the case where the pressure and flowrate do not reach constant values, the initial estimations are provided by the closed-form solution. Then, the pressures, flow rates, and leakage coefficient are estimated by solving the system of differential equations. This system is then discretized with respect to the location variable to yield the system state equations which, in turn, are...

Developing a Simulator for Concurrent Execution of Multiple Workflows in Fog Computing Environment

, M.Sc. Thesis Sharif University of Technology Rayej, Mohamad Amin (Author) ; Izadi, Mohamad (Supervisor)

Abstract

Fog computing environment consists of several devices which distribute across an arbitrary topology. Each of these devices is capable of carrying out a designated computation simultaneously with other devices. One of the common ways of describing a computation is through the usage of workflows. Workflow is a flexible and formal way of modeling tasks and their requirements for execution. A workflow is essentially a DAG. Therefore, it can model the data dependency between tasks quite accurately. The complex structure of a workflow in conjunction with the homogenous nature of devices in a fog environment makes it difficult to find a resource management algorithm to minimize execution time, used...

Investigation of the Drop Tank Influence on Range and Optimization of Its Geometry

, M.Sc. Thesis Sharif University of Technology Nasiri Khansari, Mohamad Tagi (Author) ; Durali, Mohamad (Supervisor)

Abstract

This project focuses on the design of fuel drop tanks for airplanes that add minimal drag and positive lift to the flying object. This will obviously effect the stability and dynamic performance of the airplane. To reduce adverse dynamic effects the tank was divided to several segment with a special emptying sequence. The add-on tank has to have no interference with the object existing systems and require minimum structural changes in the object. Several designs were proposed and the one gaining highest marks was selected. The flow field and the dynamic behavior of combined vehicle and drop tanks were studied using FE simulations. The result shows that adding a drop tank with optimized...

Physical Modeling to Iimpact of Burial Depth of Pipe in Soil Slopes Under Dynamic Loading

, M.Sc. Thesis Sharif University of Technology Derakhshan Ghazani, Reza (Author) ; Jafarzadeh, Fardin (Supervisor)

Abstract

Buried pipelines as vital arteries,which will play a major role in human life should be designed and implemented in such a way that withstand the least possible harm with regard economic issues.In this study we tried to use a physical model, the impact of pipeline buried in soil slope under dynamic load are examined.To achive this goal we use a rigid metal bax with dimensions of 301.5*101.5*155 cubic meters for modeling. Pipes used in these experiments has a diameter of 1.6 cm which are connected by a fulcrum to the wall box. In order to measure strain generated in the pipe we use a series of strain gauges that were installed using the pipe at some points. Physical models made on Sharif...

Pull-in criteria of a non-classical microbeam under electric field using homotopy method

, Article Scientia Iranica ; Volume 25, Issue 1 , 2018 , Pages 175-185 ; 10263098 (ISSN) Derakhshan, R ; Ahmadian, M. T ; Firoozbakhsh, K ; Sharif University of Technology

Sharif University of Technology 2018

Abstract

In this study, a homotopy analysis method was used to obtain analytic solutions to predict dynamic pull-in instability of an electrostatically-actuated microbeam. The nonlinear describing equation of a microbeam affected by an electric field, including the fringing field effect, was obtained based on strain gradient elasticity, couple stress, and classical theory. Influences of different parameters on dynamic pull-in instability were investigated. The equation of motion of a double-clamped microbeam was discretized and solved by using Galerkin's method via mode summation. The resulting non-linear differential equation was also solved by using the Homotopy Analysis Method (HAM). The influence...

Parallel machine scheduling problem with preemptive jobs and transportation delay

, Article Computers and Operations Research ; Vol. 50, issue , Oct , 2014 , p. 14-23 Shams, H ; Salmasi, N ; Sharif University of Technology

2014

Abstract

In this research the parallel machine scheduling problem with preemption by considering a constant transportation delay for migrated jobs and minimization of makespan as the criterion i.e., Pm|pmtn(delay)|Cmax is investigated. It is assumed that when a preempted job resumes on another machine, it is required a delay between the processing time of the job on these two machines. This delay is called transportation delay. We criticize an existing mathematical model for the research problem in the literature [Boudhar M, Haned A. Preemptive scheduling in the presence of transportation times. Computers & Operations Research 2009; 36(8):2387-93]. Then, we prove that there exists an optimal schedule...

Experimental study of two-phase oil – Polymer flow in horizontal flow path

, Article Experimental Thermal and Fluid Science ; Volume 100 , 2019 , Pages 62-75 ; 08941777 (ISSN) Shams, R ; Shad, S ; Sharif University of Technology

Elsevier Inc 2019

Abstract

Two-phase flow inside the oil and gas wells and flow path lines is a usual occurrence in petroleum and petrochemical studies. Due to its complexity, flow transfer parameters such as hold up and pressure drop and their dependency on the flow regime maps are not well understood yet. This study is aimed at analyzing holdup for oil- water system and evaluation of this parameter by means of Image processing under different available flow regime conditions. In addition, different oil-polymer systems have been studied to evaluate the impact of polymer concentration on transport criteria. The experimental setup used for this study is consisted of a 12 m long Plexiglas pipe with an inner diameter of...

Experimental study of two-phase oil – Polymer flow in horizontal flow path

, Article Experimental Thermal and Fluid Science ; Volume 100 , 2019 , Pages 62-75 ; 08941777 (ISSN) Shams, R ; Shad, S ; Sharif University of Technology

Elsevier Inc 2019

Abstract

Two-phase flow inside the oil and gas wells and flow path lines is a usual occurrence in petroleum and petrochemical studies. Due to its complexity, flow transfer parameters such as hold up and pressure drop and their dependency on the flow regime maps are not well understood yet. This study is aimed at analyzing holdup for oil- water system and evaluation of this parameter by means of Image processing under different available flow regime conditions. In addition, different oil-polymer systems have been studied to evaluate the impact of polymer concentration on transport criteria. The experimental setup used for this study is consisted of a 12 m long Plexiglas pipe with an inner diameter of...

Seismic Design of Substation Structures with Consideration of IEEE-693

, M.Sc. Thesis Sharif University of Technology Shams, Mohammad (Author) ; Mofid, Massoud (Supervisor)

Abstract

The Reliability of substation structures with consideration of earthquake uncertainties is one of the most important subjects in structural analysis in recent years. In this project we first introduce IEEE-693-2005, which is the most effective and comprehensive seismic design code for electronic substations. Also in second chapter the rudimentary aspects of Reliability Theory and methods for evaluating the reliability of substation structures is introduced. Then with modeling the most common and most important electronic substation devices in Iran, with consideration of all seismic parameters and their uncertainties, the reliability of these structures evaluated. In this project for...

Scheduling on Parallel Machines with Preemption and Transportation Delays using a Particle Swarm Optimization (PSO)-Based Algorithm

, M.Sc. Thesis Sharif University of Technology Shams, Hesam (Author) ; Shadrokh, Shahram (Supervisor)

Abstract

This research deals with the problem of scheduling independent preemptive jobs on identical parallel machines, to minimize the total completion time (makespan). The transportation of an interrupted job from a machine to another machine requires considering a constant transportation delay i.e., Pm|prmp(delay)| Cmax. This delay is called transportation delay. We propose a Mixed Integer Linear Programming formulation for the research problem in case of two machines i.e., P2|prmp(delay)| Cmax. Since the research problem is shown to be NP-hard, a particle swarm optimization (PSO) algorithm is applied to solve the problem approximately. Based on the frequency of using local search procedure, three...

Speaker Adaptation in Eigen Voice Space for Statistical Parametric Speech Syntheis

, M.Sc. Thesis Sharif University of Technology Shams, Boshra (Author) ; Sameti, Hossein (Supervisor)

Abstract

Recently various speaker adaptation methods in HMM-based speech synthesis are proposed. The importance of adaptation techniques is that we can design a system in which speech is generated with high quality and target speaker characteristics through limited adaptation data sets.
In this research, we focus on adaptation based on clustering and develop a new and novel method using eigenvoices in order to adapt a new speaker. We employ this approach for the first time in HSMM-based speech synthesis systems and its goal is to reduce the parameters and adaptation data of the system. In our proposed method, first some speaker dependent models are trained. For each model we combine the...

A Simulation for Better Understanding of Integrin Clustering and Activation

, M.Sc. Thesis Sharif University of Technology Shams, Shahab (Author) ; Motahhari, Abolfazl (Supervisor)

Abstract

Today, computer simulations are employed prevalently by researchers to understand biological processes. The tendency to use computational methods has been increased recently due to the high costs and errors of experimental methods. Integrins are membrane proteins that mechanically attach cells to the extra cellular matrix (ECM) and derive some behaviors such as cell migration. Moreover, integrins have biochemical functions. They transduce environment signals and trigger chemical pathways. As a result, integrins regulate cell shape, motility, etc. The investigation of integrin behavior in a real environment is very difficult due to the presence of many other proteins that interfere with the...

Post-Quantum Authentication and Communication Security for Drone Networks

, M.Sc. Thesis Sharif University of Technology Derakhshan Rudsari, Parya (Author) ; Bayat Sarmadi, Siavash (Supervisor)

Abstract

Modern societies rely on a complex network of interconnected devices and individuals to fa- cilitate the exchange and monitoring of information. In this manner, drones function as flying smart nodes in the wireless network ecosystem, collecting, monitoring, and transmitting data. This dynamic and thriving technology serves diverse applications, including navigation, re- mote sensing, and disaster response. However, drone networks face critical challenges, such as data security, privacy preservation, and device interoperability. Traditionally, drone net- works’ security relies on classical cryptographic methods, such as elliptic curve cryptography and hash functions. However, recent advances...

Synthesis of Heterogeneous Catalysts Based On Metal-Organic Framework and Investigation of Their Application in C-C Coupling Reaction

, M.Sc. Thesis Sharif University of Technology Derakhshan Mehr, Ali (Author) ; Matloubi Moghaddam, Firouz (Supervisor)

Abstract

Since nanocatalysts have gained particular importance in various fields of chemistry, in this research, nanocatalysts based on metal-organic frameworks were initially made and used for multicomponent reactions, and C-C cross-coupling has been used. ZIF-8@SiO2@Pd, ZIF-67@MPDA, ZIF-8@MPDA, BMZIF@ MPDA catalysts are porous and stable cubic carbon-based catalysts based on nanoparticles. In addition, the product yields were good to excellent for all reactions under mild conditions, resulting from the superior activity of the synthesized heterogeneous catalyst containing cobalt and zinc. Also, these catalysts can be easily separated by a centrifuge and used in the next step without any noticeable...