Numerical Simulation and Modeling of Electrochemical Processes in Lithium Titanate Oxide Batteries

, M.Sc. Thesis Sharif University of Technology Hassani, Elham (Author) ; Rajani Ghahnavieh, Abbas (Supervisor) ; Torabi, Farshad (Co-Supervisor)

Abstract

Batteries have always been used as one of the most important sources of electricity storage and supply. Among different types of batteries, lithium-ion batteries are widely used in various fields and engineering applications due to their high-density energy/power, high discharge/charge rate, and long life. The most common of these applications are using these batteries in all-electric and hybrid vehicles, which reduce environmental problems. Due to the high cost of these types of batteries and the environmental issues of battery decomposition, researchers are seeking to discover long-lasting batteries that lithium titanate oxide batteries have the most extended lifespan among lithium-ion...

Analysing the Effects of Monetizing Energy Carriers Subsidy on Expenditures and Welfare Criteria of Iranian Households

, M.Sc. Thesis Sharif University of Technology Einian, Majid (Author) ; Fatemi, Farshad (Supervisor)

Abstract

In this thesis, with a review on policy simulation and economic reform analysis literature, we design a suitable method to analyze the effects of monetizing energy carriers subsidy on welfare criteria of Iranian households. The selected method is limited general equilibrium that needs demand estimates of goods, services and energy. In firs step,based on 13 years of data on “Iranian Households’ Expenditures and Income” surveys, data are provided as a pseudo-panel. Demand equations are estimated using “Seemingly Unrelated Regressions” for panel data, and elasticities are calculated. In the next step, we evaluated the equivalent variation and equivalent gain measures in each price scenarios....

Adverse Selection in Iranian Life Insurance Market

, M.Sc. Thesis Sharif University of Technology Mirtaher, Abdolkarim (Author) ; Fatemi, Farshad (Supervisor)

Abstract

This thesis finds evidence for the presence of adverse selection in the Iranian life insurance market. We use a unique dataset including more than one million policyholders’ profile information alongside their chosen life insurance coverage from the largest Iranian insurance company. Our results not only find evidence in support of adverse selection in this market, but also consider the magnitude of adverse selection relatively notable. Moreover, we found that in addition to the coverage, the other dimensions of contract could be the potential source of adverse selection. Particularly, we focused on the insurance duration and the payment method (monthly, annually, all-in-advance)....

Effect of lateral placement of ceramic and metal grains on thermal stress distribution throughout FGMS

, Article 28th Congress of the International Council of the Aeronautical Sciences 2012, ICAS 2012 ; Volume 3 , 2012 , Pages 1878-1884 ; 9781622767540 (ISBN) Torabi, A ; Abedian, A ; Sharif University of Technology

2012

Abstract

The properties of Functionally Graded Materials (FGM) are characterized by gradual variation of volume fraction of their constituents or phases over the thickness direction. They are normally ceramic in one side and metal in the other side. This kind of material has been employed as thermal barrier and also as coatings in many applications including turbine blades. Thermal stress behavior of FGMs is normally studied by simulating the material as a composite laminate where the properties ofeach layer are found by averaging the properties and volume fraction of FGM constituents through the thickness of the layer. However, it should be mentioned that the grains of FGM constituents are usually...

A kinetic study on the electrodeposition of nickel nanostructure and its electrocatalytic activity for hydrogen evolution reaction

, Article Journal of Applied Electrochemistry ; Volume 40, Issue 11 , November , 2010 , Pages 1941-1947 ; 0021891X (ISSN) Torabi, M ; Dolati, A ; Sharif University of Technology

2010

Abstract

The electrodeposition of nickel was studied using electrochemical techniques in different electrolytes and various agents. The voltammetry analysis clearly showed that the electrodeposition of nickel was a diffusion-controlled process associated with a typical nucleation process. The current transients represented instantaneous nucleation with a typical three-dimensional (3D) growth mechanism. Scharifker's equations were derived for instantaneous and progressive nucleation of the 3D growth of the spherical centers under diffusion-controlled condition. The number of nucleation sites increased with the increment in overpotential and Ni 2+ concentration. Atomic force microscopy was used to...

An investigation of the surface morphology of nanostructured nickel thin films prepared by electrodeposition

, Article International Journal of Surface Science and Engineering ; Volume 10, Issue 5 , 2016 , Pages 444-455 ; 1749785X (ISSN) Torabi, M ; Dolati, A ; Sharif University of Technology

Inderscience Enterprises Ltd 2016

Abstract

Nickel nanostructure thin films were electrodeposited on copper plates to investigate the fractal study. Scharifker's equations were derived for instantaneous and progressive nucleation and 3D growth of hemispherical centres under diffusion-controlled condition to calculate in situ change of fractal dimension of surface. It was assumed that the layer could be formed completely when fractal dimension of surface inclined to 2. Moreover, the fractal analysis of atomic force microscopy (AFM) images has confirmed the presumed model. Also, the power values of power spectral density (PSD) of the AFM images were determined using fast Fourier transform (FFT) algorithms. The PSD plots are approximated...

A novel approach for robust control of single-link manipulators with visco-elastic behavior

, Article 10th International Conference on Computer Modelling and Simulation, EUROSIM/UKSim2008, Cambridge, 1 April 2008 through 3 April 2008 ; 2008 , Pages 685-690 ; 0769531148 (ISBN); 9780769531144 (ISBN) Torabi, M ; Jahed, M ; Sharif University of Technology

2008

Abstract

Overwhelming number of control laws has been studied for control of robot manipulators with rigid links and joints. However controllers designed under this assumption may not accurately control the manipulator link due to visco-elastic properties that appear in the link behavior. In this study, a novel approach for robust control of a single-link manipulator is presented to force the link to have rigid motions, while it has visco-elastic behavior. In this regard, initially robot dynamics is extracted, followed by the design of four appropriate controllers through the loop-shaping approach. The obtained model is first represented in state space, however later converted to transfer function...

Physical Modeling of Effect of Liquefaction-Induced Lateral Spreading on Single Piles

, M.Sc. Thesis Sharif University of Technology Torabi, Hooman (Author) ; Haeri, Mohsen (Supervisor)

Abstract

Pile foundations suffered severe damages during the past earthquakes in all around the world. These damages were more severe in laterally spreading grounds and they mostly have been observed in gently sloping grounds and coastal areas. In these cases, Pile foundations not only are subjected to structures inertial loads and kinematic loads of liquefied soil but also lateral spreading intensifies damages. Thus, in the recent decade, several researches have been conducted to investigate the behavior of pile foundations in liquefiable and laterally spreading grounds, however, some uncertainties still remain in modeling of soil-pile interaction. In this study, the effects of liquefaction- induced...

“Determination of Economic Order and Production Quantity in Inventory System Regarding the Quality of Items”

, M.Sc. Thesis Sharif University of Technology Torabi, Hassan (Author) ; Haji, Rasoul (Supervisor)

Abstract

EOQ and EPQ models have been among the most important and commonly used techniques for about 100 and 60 years respectively .But, they are involved in some assumptions that sometimes prevent them from being implemented in real situation of industry and production. One of these unrealistic assumptions is that all of items received or produced are of perfect quality. In order to overcome this constraint and make the mentioned models closer to the real environmentsome researches have been done. To this end,following the previous attemptsin this project we assumed to have destructive inspections and existence of imperfect and rejected items after rework. In our models, considering 3 circumstances...

Existence of Global Solution for Two Models of Cancer Invasion

, M.Sc. Thesis Sharif University of Technology Torabi, Mousa (Author) ; Hesaaraki, Mahmoud (Supervisor)

Abstract

In this thesis we investigating two models of cancer invasion .First, a general mathematical model of cancer invasion is presented. In this model there are three factors: tumor cell, extracellular matrix and enzyme. The model consists of a parabolic partial differential equation (PDE) describing the evolution of tumor cell density , an ordinary differential equation modeling of extracellular matrix and a parabolic PDE governing the evolution of the matrix degrading enzyme concentration. This model is investigated in two special versions for existence and uniqueness of global solutions. In the first model we neglect the remodeling term, this model is named the chemotaxis-haptotaxis model....

An Integrated Simulation-DEA Approach to Multi-criteria Ranking of Scenarios for Execution of Operations in a Construction Project

, M.Sc. Thesis Sharif University of Technology Torabi, Mojtaba (Author) ; Mahlooji, Hashem (Supervisor)

Abstract

Before a construction project gets under way an attempt is made to examine different ways and scenarios for its implementation. Through such a process the more appropriate scenarios should be selected based on several criteria that are not necessarily at the same level in terms of importance. The purpose of this study is to examine different scenarios for implementing operations in the pre-construction phase of a project, based on several competing criteria with different importance levels in order to achieve a more efficient execution plan. This paper presents a new framework that integrates discrete event simulation (DES) and data envelopment analysis (DEA) to rank different scenarios for...

Impedance Control of a Knee Rehabilitation Exoskeleton Using Robust Adaptive Control

, M.Sc. Thesis Sharif University of Technology Torabi, Mansour (Author) ; Vossoughi, Gholamreza (Supervisor)

Abstract

The present study deals with designing controller for Therapeutic Exercise Robots which belongs to larger group namely Rehabilitation robots. Therapeutic exercise robots are often realized in shape of exoskeleton robots. The main line of present research is involved with, designing controller for lower limb therapeutic exercise robots and offering and implementing technical rehabilitation ideas. Firstly, in order to have a reliable position-control, considering practical limitations (e.g. system uncertainties), a robust adaptive control has been designed. Adaptive control can deals with parameters uncertainties and covering unstructured uncertainties (e.g. disturbance and noise) can be...

Analysis and Simulation of Mars Rover Curiosity in the X and UHF Bands

, M.Sc. Thesis Sharif University of Technology Torabi, Masoud (Author) ; Forouhar, Farzaneh (Supervisor)

Abstract

Mars rover Curiosity is a mobile scientific laboratory which it’s mission is to assess the biological potential of the landing site and characterize the geology of the landing region. This rover communicate to a Mars orbiter named MRO satellite in the UHF band which relies the signals to the Earth stations. Also this rover communicate to the Earth stations directly in the X band. In this thesis, we determine the technical characteristics of stations and simulate Earth-Mars radio links. So we calculate :
1. determine the technical characteristics of Earth stations
2. determine the technical characteristics of satellite and Curiosity
3. Earth-Mars orbital position in the...

Thesis Submitted in Partial Fulfillment of the Requirements for the Master's Degree in TEFL

, M.Sc. Thesis Sharif University of Technology Torabi, Fariba (Author) ; Salehi, Mohammad (Supervisor)

Abstract

In the last decades, Reaction Time research has been extended to cognitive science and more specifically human information-processing research and has gained momentum (Shim, 1996). The present study examined the reaction time in processing marked and unmarked structures with regard to the four types of conditionals (considered as unmarked, less marked, marked and strongly markedness, respectively) and prepositions (preposition pied piping that is considered as unmarked and preposition stranding as marked). To this end, two softwares were developed for which the items relating to conditionals were chosen from the Bernet’s test (1985) and the ones pertinent to prepositions were taken from...

Studying the Characteristics of 2D Materials for Electronic Circuits Devices Master Thesis

, M.Sc. Thesis Sharif University of Technology Torabi, Naghmeh (Author) ; Fardmanesh, Mehdi (Supervisor)

Abstract

The need for further improving the operation of the electronic and optoelectronic devices to raise the speed of the circuits, and to decrease their power dissipation, has led many researchers to investigate the structure of 2D material, such as graphene, transition metal dichalcogenides (TMDs) as MoS2, and other 2D compounds such as BN, due to their prominent electronic properties. TMDs have the highest significant potential for the next generation transistors due to their salient semiconductor characteristics such as electron mobility, band gap, and conductivity. For instance, Graphene is a favorable candidate for analog devices due to zero bandgap. Regarding the importance of bandgap in...

Impedance analysis of growth and morphology of electropolymerized polypyrrole nanocomposites [electronic resource]

, Article Journal of New Materials for Electrochemical Systems ; 2014, Volume 17, Number 2 Torabi, M. (Morteza) ; Sadrnezhaad, S. K ; Sharif University of Technology

Abstract

Pure polypyrrole (PPy), PPy/Al2O3 and PPy/SiO2 nanocomposites synthesized galvanostatically using different polymerization charges. Electrochemical impedance measurements of pure polypyrrole revealed that the film thickness affected the impedance responses. The characteristic frequencies vs. film thickness that obtained using Cole-Cole plots showed that electrodeposition mechanism changed from 3D to 1D after nuclei overlapping for pure PPy. Analysis of the nanocomposites impedance spectrums revealed no changes during the film growth, i.e. deposition continues 3D even after nuclei overlapping. Scanning electron microscopy (SEM) confirmed the impedance results and showed that the morphology of...

Integrated procurement, production, and delivery scheduling in a generalized three stage supply chain [electronic resource]

, Article International Journal of Industrial and Systems Engineering (JISE)-Iranian Institute of Industrial Engineering ; 2009, Vol. 3, No. 3, pp. 189-212 Nikandish, N. (Nasser) ; Eshghi, Kourosh ; Torabi, S. Ali ; Sharif University of Technology

Abstract

In this research, we investigate a three-stage supply chain with one supplier, several manufacturers and multiple retailers where the supplier provides a common raw material to each manufacturer, who in turn uses a single stage production facility to convert it into final products that are delivered at fixed lot sizes to retailers. An integrated economic procurement, production, and delivery model is developed whose objective is to find the common production cycle length, production sequences of final products at manufacturers and delivery frequencies of final products to retailers minimizing the total costs of considered supply chain. We propose an analytical solution procedure and an...

Analyses of Effect of Bank Branching on Deposit Market Share and Market Size in Iran Banking Industry

, M.Sc. Thesis Sharif University of Technology Yousefi, Fateme (Author) ; Fatemi, Farshad (Supervisor)

Abstract

This thesis aim to the study of the effect of bank’s branching decisions on deposit market. Using panel data banks from Iran, we study effect of branching on market share and market size. In theoretical part, we assume that banks maximize discounted flow of the profits. We also assume that the banks take into account the reaction from rival banks in setting number of branches. Banks are assumed to expect the rival banks react by a lag of one period. In empirical part, in order to distinguish between aggregate market size effect and market share effect, we rewrite quantity of deposit in banks as the product of aggregate deposit and market share. We specify deposit market share function with...

Investigation of Hamrahe-Aval Demand Services

, M.Sc. Thesis Sharif University of Technology Hosseinabadi, Mahsa (Author) ; Fatemi, Farshad (Supervisor)

Abstract

In the past few years mobile usage is increasing in Iran. Since mobile industry is growing and new innovations are presented, the competition between operators is rising. Although this competition has a great influence on the mobile demand for each operator, lack of the data of the all operators made us to use the data of one of the operators to investigate the demand. Based on the subscriber’s data of Hamrahe-Aval company, it has been introduced an estimation of a demand system for customers of this company by using AIDS model in this essay. This model includes three groups of services: sending short messages, calling to mobile numbers and calling to fixed numbers.
This study has two...

The Static and Dynamic Relationship between Monetary and Multidimensional Poverty Approaches

, M.Sc. Thesis Sharif University of Technology Goodarzi, Marzieh (Author) ; Fatemi Ardestani, Farshad (Supervisor)

Abstract

The identification of the poor and the elimination of their poverty always has been the subject of discussion among researchers and policymakers. Today, most researchers consider poverty as a multidimensional phenomenon, and in addition to income indicator, it has indicators related to the level of knowledge, awareness, well-being and the health of individuals. The study of multidimensional poverty and the search for the discovery of its static and dynamic relationship with income-based poverty is the subject of this research. The analysis shows that both statically and dynamically, there is a substantial mismatch in the identification of the poor households according to these two...