Analytical Modelling and Optimization of Disk Type, Slot Less Resolver

, M.Sc. Thesis Sharif University of Technology Moheyseni, Atefeh (Author) ; Nasiri Gheidari, Zahra (Supervisor)

Abstract

Resolvers, due to their robust structure, are widely used in automation systems. Among the types of resolvers, the accuracy of the Wound Rotor (WR) resolver in the occurrence of common mechanical errors is higher than other types of resolvers. therefore, in this thesis, an AFWRR is studied to improve the performance. Increasing the number of poles in WR resolvers is a good solution for increasing the accuracy of these electromagnetic position sensors. However, high-speed WR resolvers due to employing fractional slot windings suffer from rich sub-harmonics in the induced voltages. A common solution for suppressing the undesirable sub-harmonics is using multi-layer winding with appropriate...

Slotless disk type resolver: a solution to improve the accuracy of multi-speed wound rotor resolvers

, Article IEEE Transactions on Transportation Electrification ; 2021 ; 23327782 (ISSN) Moheyseni, A ; Nasiri Gheidari, Z ; Alipour Sarabi, R ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2021

Abstract

A common solution for increasing the accuracy of wound-rotor (WR) resolvers is to increase the number of poles. To achieve a compact design, fractional slot concentrated winding is used for multi-pole WR resolvers. However, employing such windings leads to rich sub-harmonics in the induced voltages. To suppress these undesirable sub-harmonics, multi-layer windings with appropriate shifting angle between the layers is suggested. However, the said shifting angle is limited by the slot pitch so that the capability of the multi-layer winding is not utilized fully. To overcome the mentioned deficiency a slotless disk type configuration is proposed in this paper. Then, an optimization based on the...

Slotless disk type resolver: a solution to improve the accuracy of multi-speed wound rotor resolvers

, Article IEEE Transactions on Transportation Electrification ; Volume 8, Issue 1 , 2022 , Pages 1493-1500 ; 23327782 (ISSN) Moheyseni, A ; Nasiri Gheidari, Z ; Alipour Sarabi, R ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2022

Abstract

A common solution for increasing the accuracy of wound-rotor (WR) resolvers is to increase the number of poles. To achieve a compact design, fractional slot concentrated winding (FSCW) is used for multi-pole WR resolvers. However, employing such windings leads to rich sub-harmonics in the induced voltages. To suppress these undesirable sub-harmonics, multi-layer windings with an appropriate shifting angle between the layers are suggested. However, the said shifting angle is limited by the slot pitch so that the capability of the multi-layer winding is not utilized fully. To overcome the mentioned deficiency, a slotless disk type configuration is proposed in this article. Then, an...

Dynamics of Protein-Embedded Vesicles in Simple Shear Flow

, M.Sc. Thesis Sharif University of Technology Hoore, Masoud (Author) ; Jalali, Mir Abbas (Supervisor) ; Khoshnood, Atefeh (Co-Advisor)

Abstract

Studying the dynamics of vesicles in simple shear flow is the first step to decipher the dynamics of cells in flows or the motion of vesicle-based nanoparticles in vessels for drug delivery. The deformation of vesicle in shear flow changes the permeability of its membrane and may lead to its rupture, both of which correlate with the transportation of vesicle cargos to their environment, especially important in drug delivery. The deformation of vesicles in shear flow not only depends on the physical properties of the whole system, such as temperature, but also on the mechanical properties of three media: vesicle membrane plus vesicle’s inner and outer fluid. The effect of the mechanical...

Effects of Graphene Nanopores and Temperature on DNA Sequencing Using Molecular Dynamics

, M.Sc. Thesis Sharif University of Technology Majdi, Amin (Author) ; Meghdari, Ali (Supervisor) ; Khoshnood, Atefeh (Co-Advisor)

Abstract

Distinguishing the structure of DNA is of outmost importance in the medicine and agriculture industry nowadays. Various methods have been suggested so far; however, high costs, incorrect results, and time-taking process are among main defects of them. Scientists try to find new ways for recognizing DNA structure and system in order to overcome such problems. One of these new methods is absorbing and passing DNA through Nano-pores in an electrolyte solution under the influence of an electrical field. The basis of this method is the ionized currents which occur due to the passing of DNA through Nano-pores. Because each DNA base pairs can form a barrier corresponding to a unique measured value,...

Oxidation of Sulfides and Olefins in the Presence of Nanocluster Polyoxotungstate–intercalated Layered Double Hydroxide Nanoparticles as a Catalyst

, M.Sc. Thesis Sharif University of Technology Qoreishi Kavardi, Atefeh Sadat (Author) ; Bagherzadeh, Mojtaba (Supervisor)

Abstract

In this study, polyoxometalate (POM) intercalated in the layered double hydroxide (LDH) was synthesized by a selective ion-exchange method. For this purpose, the nanocluster [VW12O40]3- was immobilized on the Mg2+/A13+/Cl–LDH support. The heterogeneous catalyst was characterized by FT-IR, XRD, SEM and analysis of ICP. The LDH-POM was applied as a catalyst in efficient oxidation of sulfides to sulfoxides using UHP as oxidant and CH3OH/ CH¬2¬Cl¬2 ¬as a solvent at room temperature, as well as epoxidation of olefins using TBHP as an oxidants and C¬2H4Cl2 as a solvent in 84°C. This catalyst showed excellent catalytic activities for a substrate/catalyst ratio (200:1). For example, this catalytic...

Long Period Variable Stars in the Local Group Galaxies

, M.Sc. Thesis Sharif University of Technology Hashemi, Azim (Author) ; Rahvar, Sohrab (Supervisor) ; Javadi, Atefeh (Co-Supervisor)

Abstract

In this thesis, the star formation history and evolution of IC 1613 dwarf galaxy and NGC 5128 giant elliptical galaxy has been studied. About IC 1613, our result shows that the star formation history of the galaxy is roughly constant in 5 Gyr ago and this support that the galaxy had been isolated at least in 5 Gyr ago. About NGC 5128, we can see that the star formation rate has suddenly increased in 700 Myr and 3.5 Gyr ago. This results in very good agreement with literature support that the galaxy has experienced some mergers with smaller gas rich galaxies

Study and Comparison the Incidence of Dutch Disease in Iranian Economy in Two Periods of Oil Shock

, M.Sc. Thesis Sharif University of Technology Momeni, Atefeh Sadat (Author) ; nili, Masoud (Supervisor) ; Madanizadeh, Ali (Supervisor)

Abstract

This paper studies and compares the effect of "Dutch disease" in Iranian economy in two periods of rising oil price (1973-1978) and (2004-2010). The study presents a DSGE model to analysis the behavior of economic variable in both periods and to address this question that whether or not policy maker has learning behavior. The model consists of households, final goods producers who divided in tradable goods and non-tradable goods sector and the government. I use calibration methods to estimate models parameters.Comparison of simulated results and the actual macroeconomic variables in Iran during 1338-1390 indicates that, first of all Dutch disease effect occur in both periods of oil shock so...

The Effect of Hydrophobic Mismatch and Rigidity of Protein on the Cluster Formation of Transmembrane Proteins in Biomembranes

, M.Sc. Thesis Sharif University of Technology Jafarinia, Hamid Reza (Author) ; Ahmadiyan, Mohammad Taghi (Supervisor) ; Jalali, Mir Abbas (Co-Advisor) ; Khoshnood, Atefeh (Co-Advisor)

Abstract

Membrane proteins aggregation is a very important biological phenomenon in a variety of cell functions. It has been suggested that aggregation behavior of membrane proteins is influenced by the shape of the hydrophobic domain of the proteins, proteins hydrophobic mismatch and bilayer curvature. However, in this study by means of coarse grained membrane simulations it has been found that in thermal equilibrium, protein-protein interactions also depend on protein rigidity and structural strength. Based on simulation results, we have observed stable large clusters even in the absence of hydrophobic mismatch between lipids and proteins. Interestingly, our results also indicate that proteins with...