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zare-soheili--hossein
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Synthesis of new Modified Composites Based on Nanoporous Materials and their Application in Environmental Pollutant Degradation
, M.Sc. Thesis Sharif University of Technology ; Gholami, Mohammad Reza (Supervisor)
Abstract
In this projekt, nanophotocatalysts containing metal oxides and oxy-acids based on the nanoporous materials were synthesized. The photocatalytic properties of the prepared samples were evaluated by the photodegradation of day moleculs in photocatalytic systems. The catalytic results revealed that Ag3VO4/Cu-MOF/rGO exhibits noticeably an improvement in both efficiency and rate of AB92 photodegradation in comparison with the pure Ag3VO4. Using different scanning mechanisms for the catalytic properties of the synthesized nanocomposites, it was clearly demonstrated that the anionic superoxide plays a decisive role. Reduction of 4-NP in the presence of NaBH4 was also used to investigate...
6DOF Flight Dynamics Modeling of a Flexible Flapping wing using Unsteady Aerodynamics
, Ph.D. Dissertation Sharif University of Technology ; Pourtakdoust, Hossein (Supervisor)
Abstract
A complete 6DOF flight dynamic model of an elastic flapping wing (EFW), integrated with unsteady aerodynamic theory is developed. In this respect, initially efficient high fidelity modules for EFW structural dynamics (SD) as well as unsteady aerodynamics loadings (UAL) to be coupled with its flight dynamics are prepared. A modal approach is followed to model structural dynamics of plain and 3D EFWs. This is in contrast with the Euler-Bernoulli beam theory that is mostly utilized for SD in the existing literature. In addition, due to the possibility of large wing deformations as well as the existence of non-linear displacement regime for realistic EFW flights, non-linear modal approaches such...
Hydrodynamic Modeling and Control of SWATH Vessel
, M.Sc. Thesis Sharif University of Technology ; Sayyadi, Hassan (Supervisor) ; Karimi, Mohammad Hossein (Supervisor)
Abstract
One of the key issues in the design of vessels is their proper stability and performance in waves. Therefore, the use of twin-hull vessel designs such as conventional catamaran and SWATH is suitable for improving stability and seakeeping quality. Although SWATH has a better seakeeping quality than a conventional catamaran, it has been observed that at high forward speeds, especially in head waves, the vertical motions of the vessel is greatly enhanced. Various methods such as correction of the hull form and the use of fin stabilizers can be used to modify SWATH vessel motion behavior. These control surfaces can respond appropriately to the dynamic forces from the waves, reducing the motions...
Electrical Distribution System Planning in Multi-Microgrid Framework
, M.Sc. Thesis Sharif University of Technology ; Ehsan, Mehdi (Supervisor) ; Farzin, Hossein (Co-Supervisor)
Abstract
Remote-controlled switches (RCSs) have the ability to quickly isolate the faulted area from other parts of distribution systems. On the other hand, the distributed generation resources (DGs) and tie lines can supply the interrupted loads after fault occurrence as a microgrid. In this regard, this thesis proposes a planning model for simultaneous placement of RCSs, DGs, and tie lines in distribution systems with complex topologies to improve their reliability and resiliency. Presence of renewable DGs (RDGs) including photovoltaic cells (PVs) and wind turbines (WTs), as well as the uncertainties of loads, RDGs, and outage duration of the faulted areas are also considered in the proposed...
Novel Cu2O/Cu-MOF/rGO is reported as highly efficient catalyst for reduction of 4-nitrophenol
, Article Materials Chemistry and Physics ; Volume 237 , 2019 ; 02540584 (ISSN) ; Zare Soheili, H ; Gholami, M. R ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Cu-MOF/rGO nanocomposite was synthesized by a one-step hydrothermal method and used as proper support for Cu2O particles. Various microscopic and spectroscopic methods were applied to characterize the morphology of Cu2O/Cu-MOF/rGO nanocatalyst. Catalytic results of 4-nitrophenol reduction in the presence of NaBH4 indicate that as-synthesized nanocomposite shown significant improved activity compared with pure Cu2O particles. Enhanced catalytic performance of nanocomposite can be ascribed to the high adsorption ability of Cu-MOF and effective electron transfer due to the presence of rGO. A possible mechanism was proposed for catalytic reduction of 4-nitrophenol over Cu2O/Cu-MOF/rGO. © 2019...
Preparation and characterization of novel Ag3VO4/Cu-MOF/rGO heterojunction for photocatalytic degradation of organic pollutants
, Article Materials Research Bulletin ; Volume 121 , 2020 ; Zare Soheili, H ; Hosseinifard, M ; Gholami, M. R ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Cu-based metal organic framework/rGO was used as an effective cocatalyst to synthesis novel Ag3VO4/Cu-MOF/rGO nanocomposite. The resulting photocatalysts were characterized by different microscopic and spectroscopic methods. The photocatalytic degradation studies on acid blue 92 showed that Ag3VO4/Cu-MOF/rGO nanocomposite indicated significant improved activity compared with pure Ag3VO4 and Cu-MOF/rGO. The improved photocatalytic activity of nanocomposite was attributed to the increased surface area and effective charge carrier separation and transport in the nanocomposite. © 2019 Elsevier Ltd
Surveying Philosophical Arguments on "Origination of The Universe" based on the views of: W.L.Craig, Q.Smith and Allamah S.M.H Al-Tabatabaie
,
M.Sc. Thesis
Sharif University of Technology
;
Hosseini, Hassan
(Supervisor)
Abstract
The problem of Origination of The Universe is one of the most important issues in the history of philosophy whether in western edition or in Islamic thought. The most problematic aspect of the Origination is Temporal Origination. From about 30 years ago as a result of the works of a famous American philosopher William Lane Craig, the debate between temporality and Eternity of the Universe became a fresh topic in western philosophy. In this research we want to survey the philosophical arguments for and against the temporality of the Universe based on the views of: W.L.Craig, Q.Smith and Allamah S.M.H Al-Tabatabaie.
Design An Efficient Method for Solving Integer Programming by Lagrangian Relaxation
, M.Sc. Thesis Sharif University of Technology ; Eshghi, Kourosh (Supervisor)
Abstract
The subgradient method is one of the most favoriate methods to solve discrete optimization problems. The Easy Implementation and flexibility enbles us to solve a vast types of complicated combinatorial optimization problems. However, the algorithm can be improved by adjusting its parameters and steps.In present research, we present a heuristic structure to modify and improve the algorithm. Then, the proposed algorithm has tested on special classes of discrete optimization problems such as Generealized Assignment and Uncapacitated Warehouse location problems. The results show that the proposed algorithm can improve the efficiency of the classic form of subgradient method.The three main...
Preparation of Heterogeneous Catalysts by Immobilization of Molybdenum and Manganese-shiff Base Complexes into the Nanopores of Zeolite and SBA-15
, Ph.D. Dissertation Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
This thesisconsiders new fundamental approaches to yield heterogeneous catalysts in to three sections. The first section described the immobilization of the molybdenum-Schiff base complexes in pores of SBA-15 in two different methodologies depending on the actual structure of the complexes., (i) stepwise formation of the complex by initial covalent anchoring of one of the components and consecutive solid phase synthesis consisting of the condensation of the other components of the salen complex (iii) one-step complex immobilization by covalent binding through the ligand.Based on the first methodology, we report the preparation of ordered mesoporous silica SBA-15 containing a molybdenum...
Influence of martensite volume fraction on impact properties of triple phase (TP) steels
, Article Journal of Materials Engineering and Performance ; Volume 22, Issue 3 , 2013 , Pages 823-829 ; 10599495 (ISSN) ; Ekrami, A ; Sharif University of Technology
2013
Abstract
Ferrite-bainite-martensite triple phase (TP) microstructures with different volume fractions of martensite were obtained by changing heat treatment time during austempering at 300 C. Room temperature impact properties of TP steels with different martensite volume fractions (VM) were determined by means of Charpy impact testing. The effects of test temperature on impact properties were also investigated for two selected microstructures containing 0 (the DP steel) and 8.5 vol.% martensite. Test results showed reduction in toughness with increasing VM in TP steels. Fracture toughness values for the DP and TP steels with 8.5 vol.% martensite were obtained from correlation between fracture...
Effect of martensite volume fraction on work hardening behavior of triple phase (TP) steels
, Article Materials Science and Engineering A ; Volume 528, Issue 13-14 , 2011 , Pages 4422-4426 ; 09215093 (ISSN) ; Ekrami, A ; Sharif University of Technology
2011
Abstract
The strain hardening behavior of AISI 4340 steel with dual phase (DP) and triple phase (TP) microstructures with constant ferrite volume fractions of 34% was investigated. The microstructures of specimens were analyzed using an optical microscope. The tensile flow behavior of all the samples was explained using Holloman equation. Results showed that in both DP and TP steels, work hardening takes place in two stages. The onset strain of second stage of work hardening and Holloman equation parameters (work hardening exponent and strength coefficient) in both stages were increased with the increase of martensite volume fraction in TP steels. At first stage of work hardening, ferrite phase...
Influence of martensite volume fraction on tensile properties of triple phase ferrite-bainite-martensite steels
, Article Materials Science and Engineering A ; Volume 530, Issue 1 , 2011 , Pages 440-445 ; 09215093 (ISSN) ; Ekrami, A ; Sharif University of Technology
2011
Abstract
This paper presents the effect of martensite volume fraction (VM) on mechanical properties of AISI 4340 steel with ferrite-bainite-martensite microstructures. The steel bars were austenitized at 900°C for 1h followed by intercritical annealing at 740°C for 100min and quenching into a salt bath with temperature of 300°C and holding at different times to obtain triple phase (TP) microstructures with 34vol.% fraction ferrite and various martensite (or bainite) contents. Presence of three phases in adjacent to each other was confirmed by metallographic analysis and TEM studies. TEM observation also indicates higher density of dislocations within ferrite near martensite colonies compared to that...
Investigation on Interfacial Reactions in Aluminium to Copper Resistance Spot Welding
, M.Sc. Thesis Sharif University of Technology ; Pouranvari, Majid (Supervisor)
Abstract
With the development of electrical engineering and the electrical industry, the use of copper and its alloys has grown tremendously. On the other hand, with development and modern industry, it will be difficult to meet the requirements such as high performance, cost reduction and weight reduction of the structure if only one metal material is used in the production of the desired component or structure. Aluminum can be used in combination with copper because of its properties such as high thermal and electrical conductivity. Al/Cu bonding is used in industries such as microelectronics, automobiles and batteries. This study has investigated parametrically the feasibility of uneven bonding of...
A Fast Algorithm for Shadow Generation with Low Distortion Based on Shadow Map Technique
, M.Sc. Thesis Sharif University of Technology ; Jamzad, Mansour (Supervisor)
Abstract
Shadows are one of the most important details in graphical images. There exist many shadow generation algorithms each of which suffers from some problems. High processing time and ill-shaped shadow borders, known as alasing, are some of such problems. In this paper, we propose a heuristic method based on standard shadow map technique, named rotated shadow maps, to generate excellent hard shadows. Our method uses some shadow maps which are generated from the same view but objects are slightly rotated around the center of view area. Rotated shadow maps can be considered as an independent hard shadow generation algorithm. Also it can be combined with other shadow map based approaches. Utilizing...
Design of viscous fluid passive structural control systems using pole assignment algorithm
, Article Structural Control and Health Monitoring ; Vol. 21, issue. 7 , July , 2014 , p. 1084-1099 ; Ahmadizadeh, M ; Sharif University of Technology
2014
Abstract
A methodology is developed for the design of optimum viscous fluid passive energy dissipation systems using pole assignment active control algorithm. In this method, the procedure to assign the new structural poles is slightly modified such that the resulting structural properties (i.e., the optimum locations of system poles) can be achieved merely by modification of structural stiffness and addition of a passive control system. A combination of stiffness reduction and increase of damping is utilized to reduce both acceleration and displacement response. It is shown that the control systems designed using this method provide structural performances slightly better than or close to those of...
Design of passive viscous fluid control systems for nonlinear structures based on active control
, Article Journal of Earthquake Engineering ; 2017 , Pages 1-22 ; 13632469 (ISSN) ; Ahmadizadeh, M ; Sharif University of Technology
2017
Abstract
A practical procedure is developed for the design of passive control systems using viscous fluid dampers for nonlinear structures. The design methodology takes advantage of the modification of the damping, strength, and stiffness properties of the structure to achieve the desired relative displacement and absolute acceleration response. For this purpose, a study of poles in the complex plane is used to determine the required changes in the dynamic properties of nonlinear structures. Furthermore, a relatively simple relation between the ductility demands of highly damped single- and multiple-degree-of-freedom (SDF and MDF respectively) systems is established to reduce the computational burden...
Modified sliding mode design of passive viscous fluid control systems for nonlinear structures
, Article Engineering Structures ; Volume 162 , 1 May , 2018 , Pages 245-256 ; 01410296 (ISSN) ; Ahmadizadeh, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
A strategy is developed for design of passive control systems for structures experiencing inelastic deformations during earthquake loading. Besides the addition of passive energy dissipation devices, the proposed method suggests the required changes to the stiffness and strength of the structure, to reduce the absolute acceleration and relative deformation responses simultaneously. For this purpose, the locations and amounts of modifications in stiffness, strength and damping are determined by a sliding mode control algorithm to consider the nonlinear behavior of the structure. Being originally designed for active control, the sliding mode algorithm is modified to facilitate the extraction...
Design of passive viscous fluid control systems for nonlinear structures based on active control
, Article Journal of Earthquake Engineering ; Volume 23, Issue 6 , 2019 , Pages 1033-1054 ; 13632469 (ISSN) ; Ahmadizadeh, M ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
ABSTARCT: A practical procedure is developed for the design of passive control systems using viscous fluid dampers for nonlinear structures. The design methodology takes advantage of the modification of the damping, strength, and stiffness properties of the structure to achieve the desired relative displacement and absolute acceleration response. For this purpose, a study of poles in the complex plane is used to determine the required changes in the dynamic properties of nonlinear structures. Furthermore, a relatively simple relation between the ductility demands of highly damped single- and multiple-degree-of-freedom (SDF and MDF respectively) systems is established to reduce the...
Design of a HEV’s Controller Using Learning-based Methods
, M.Sc. Thesis Sharif University of Technology ; Boroushaki, Mehrdad (Supervisor)
Abstract
Hybrid electric vehicles (HEV) are proving to be one of the most promising innovations in advanced transportation systems to reduce air pollution and fossil fuel consumption. EMS is one of the most vital aspects of the HEV powertrain system. This research aims to design an optimal EMS under the condition of meeting the goals of drivability control, fuel consumption reduction, and battery charge stability. The current EMS is based on the classical rule-based method derived from fuzzy logic, which guides to the suboptimal solution in episodic driving cycles. Previous experiences in implementing Reinforcement Learning (RL) suffer from late convergence, instability in tracking the driving...
Helical motion wound-rotor resolver
, Article IEEE Sensors Journal ; Volume 22, Issue 10 , 2022 , Pages 9371-9377 ; 1530437X (ISSN) ; Nasiri Gheidari, Z ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
In this paper an integrated core, high reliability, linear-rotational resolver with a simple slotless configuration is proposed. The moving part of the proposed resolver has only one helical winding. While, its stator needs at least two individual windings to be able to determine the linear and angular position in simultaneous linear and rotational, helical, motions. Three different configurations are proposed for the stator's windings: (1) helical and horizontally skewed winding (2) helical and vertically skewed winding (3) horizontally and vertically skewed windings. The influence of the mentioned configurations is discussed in the terms of sensor's accuracy in independent and simultaneous...