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imanieh--alireza
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Synthesis parameters effect on the final morphology of the layered double hydroxide (LDH)
, Article Protection of Metals and Physical Chemistry of Surfaces ; Volume 53, Issue 3 , 2017 , Pages 460-465 ; 20702051 (ISSN) ; Afshar, A ; Sharif University of Technology
Maik Nauka Publishing / Springer SBM
2017
Abstract
Smart coatings which prevent corrosion by several mechanisms recently have been carefully planned. One of these mechanisms is the use of ion exchangers like LDH in the coating network. Since the morphology is the most important properties for the applications that the surface plays an important role, LDH morphology was evaluated in this study. For this purpose, the LDH contain a kind of green inhibitor was synthesized and after evaluating its performance it was examined morphologically by changing significant parameters like MII/MIII, pH, aging time and temperature. It is found that, high ratio of the MII/MIII cause thinner layer of LDH. The pH also has special effect on the surface...
Corrosion protection of aluminum by smart coatings containing layered double hydroxide (LDH) nanocontainers
, Article Journal of Materials Research and Technology ; Volume 8, Issue 3 , 2019 , Pages 3004-3023 ; 22387854 (ISSN) ; Afshar, A ; Sharif University of Technology
Elsevier Editora Ltda
2019
Abstract
In this study, the LDH containing a kind of green inhibitor (sodium molybdate) was synthesized and utilized in a poly-vinyl alcohol (PVA) base coating applied on the aluminum (5054 series) surface. After evaluating the LDH performance, the inhibitor release from the LDH crystals was examined by changing significant parameters like MII/MIII (the molar ratio of divalent ions into trivalent ions), pH, aging time and temperature. In order to find the kinetic release of intercalated inhibitor a prediction model was introduced in 3.5% NaCl solution. The model expressed that the pH as the processing parameter has special effect on the kinetic releasing of the inhibitor. It can enhance the amount of...
Corrosion Protection of Aluminium by Smart Coatings Containing Layered Double Hydroxide (LDH) Nanocontainers
, Ph.D. Dissertation Sharif University of Technology ; Afshar, Abdollah (Supervisor)
Abstract
Smart coatings which prevent corrosion by several mechanisms recently have been carefully planned. One of these mechanisms is the use of ion exchangers like Layered Double Hydroxide (LDH) in the coating network. In this study, the LDH containing a kind of green inhibitor (sodium molybdate) was synthesized and utilized in a Poly-Vinyl Alcohol (PVA) base coating applied on the aluminium (5054 series) surface. After evaluating the LDH performance, the inhibitor release from the LDH crystals was examined by changing significant parameters like MII/MIII (the molar ratio of divalent ions into trivalent ions), pH, aging time and temperature. Considering the LDH morphology or the thickness of the...
Experiments design for hardness optimization of the Ni-Cr alloy electrodeposited by pulse plating
, Article Acta Metallurgica Sinica (English Letters) ; Volume 26, Issue 5 , 2013 , Pages 558-564 ; 10067191 (ISSN) ; Yousefi, E ; Dolati, A ; Mohammadi, M. R ; Sharif University of Technology
2013
Abstract
The hardness of the Ni-Cr alloy which is electrodeposited in chloride solution, is optimized by design of experiment method (central composite design). Various parameters were evaluated in order to find significant factors in this process. Frequency, duty cycle, current density and temperature were selected as effective factors. Analyses of variance (ANOVA) were performed on the results of the designed experiments. The best model which can predict the hardness of the Ni-Cr alloy electrodeposits was found whereas the frequency and quadratic behaviour of the current density were the most significant model terms. Serious interaction of the current density with frequency and duty cycle also were...
Electrodeposition of the Ni-Cr Alloy by Pulse Plating
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor) ; Mohammadi, Mohammad Reza (Supervisor)
Abstract
In this thesis, the hardness of Ni-Cr alloys is optimized by design of experiment (DOE) method (Central Composite Design) in pulse electrodeposition performed in chloride solution. Various parameters were evaluated for finding significant factors in pulse electrodeposition of Ni-Cr alloy. Frequency, duty cycle, current density and temperature were selected as effective factors. 30 experiments were designed by the central composite design method. Analyses of Variance (ANOVA) were performed on the results of these 30 experiments. The best models which can predict the hardness, Cr content, deposition rate, thickness and cathode efficiency of Ni-Cr alloy electrodeposits were found and...
An Investigation on Deficiencies and Factors Affecting Construction Procedure; Case Study: Fars Province
, M.Sc. Thesis Sharif University of Technology ; Mofid, Masoud (Supervisor) ; Mortaheb, Mohammad Mehdi (Co-Advisor)
Abstract
Most regions in Iran are located on an active plate boundary. Therefore, many parts of the country face a risk of earthquake damage at some point in time. Therefore, anticipating and addressing the consequences of earthquake events in order to minimize loss of life and damage to property is a national issue.There is concern about the ability of a signification fraction of buildings in Iran to withstand earthquake events. The deficiencies in the design and construction of buildings in Iran result in low-quality buildings vulnerable to earthquakes. It is necessary to identify and investigate the parameters that contribute to these deficiencies.Previous research studies indicate that...
Kinetic study and growth behavior of template-based electrodeposited platinum nanotubes controlled by overpotential
, Article Materials Chemistry and Physics ; Volume 187 , 2017 , Pages 141-148 ; 02540584 (ISSN) ; Dolati, A ; Imanieh, I ; Yashiro, H ; Kure-Chu, S. Z ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
Platinum nanotubes (PtNTs) are fabricated by potentiostatic electrodeposition at various overpotentials (−200 up to −400 mV versus SCE) in polycarbonate templates (PCTs) with pore diameter of 200 nm in a solution containing 5 mM H2PtCl6 and 0.1 M H2SO4. The synthesized PtNTs are characterized by field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The electrochemical growth mechanism within nanoscopic pores and the relationship between morphological variations and kinetic parameters are investigated for the first time. It is shown that more porous structure of nanotubes forms at high overpotentials possibly due to preferably nucleation. The...
Rcci Curvature for Metric-Measure Space via Optimal Transport
, M.Sc. Thesis Sharif University of Technology ; Bahraini, Alireza (Supervisor) ; Ranjbar Motlagh, Alireza (Co-Advisor)
Abstract
One of the important questions in mathematics is generalized. In case of metric spaces, one of the questions is: Can we extend notions of Riemannian geometry to arbitrary metric spaces smoothly? Ricci curvature is one of the most important concepts in differential geometry. Ricci curvature is defined for the Riemannian manifold and has many applications in mathematics and physics like Einstein’s equation in relativity theory. There is a good notion for a metric space having “sectional curvature bounded below by K” or “sectional curvature bounded above by K”, due to Alexandrov. Can we define the concept of Ricci curvature in metric space? A motivation for this question comes from Gromov’s...
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
Seismic design codes reduce loads by using response modification factor. Because of the reserved strength in structural elements and capacity of structure to dissipate energy, structures can be designed for lower seismic loads. This factor has modified over time. In this thesis, the effect of the reduction in behavior factor on the response of two kinds of reinforced concrete systems were evaluated. Moment resisting frames and dual systems with different heights and regularity in plan, heve been design according to the behavior factor which is recommended in the 3rd edition of the Iranian codes of practice for seismic resistance design of buildings (Standard No. 2800). Drift and...
Prediction of Financial Markets Using Combination of Artificial Intelligence and Technical Analysis
, M.Sc. Thesis Sharif University of Technology ; Haji, Alireza (Supervisor)
Abstract
Generally, nowadays, machine learning methods are used in many different areas for their superiority over other methods of prediction. Although being a tough task, stock market prediction with machine learning approaches is being spread due to satisfying results published ever yday. Machine learning methods usually use varied kinds of data ,including structured data such as market data, technical indicators and some fundamental data as well as unstructured one entailing text and graph data in order to enhance their predictability capacity. In this thesis we aimed to find out more about the importance and the contribution of structured data in prediction and we tried to attain a framework...
, M.Sc. Thesis Sharif University of Technology ; Hajji, Alireza (Supervisor)
Abstract
This thesis presents an inventory control system which is based on Meta-heuristic Algorithms.In this thesis we will optimize the input values of our tree-echelon inventory model (keeping costs,stock worth,reorder costs,...) with these Algorithms. The presented method is able to determine the optimal stock level, costs of system and number of shipments in the system. The method is basically a decision support system (DES) and it is able to provide the order scheduling parameters of goods at operational level. The aim of the current research is to demonstrate that a Meta-heuristic algorithmis capable of solving complex inventory problems and with future improvements it is able to achieve...
The Ricci Flow with Applications to the Poincare and Calabi Conjectures
, M.Sc. Thesis Sharif University of Technology ; Bahreini, Alireza (Supervisor)
Abstract
Poincare conjecture is one of the rst eorts for classifying 3-manifolds that was stated in the begining of 20th century. Eorts for proving this conjecture continued for about 100 years and nally Perelman has solved it in 2003. He has used Ricci ow which has been invented by Richard Hamilton in the early 80's. In this thesis rst we will introduce Ricci ow and will state the results before Perelman such as short time and long time existence of solution. Then we will mention some applications of Ricci ow and will state an explanation of the proof of uniformization and Calabi conjecture by Ricci ow. After that we start the main part of the thesis. In this part we will montion one of the...
Feasibility And Study(CNG Cylinder Production Plant)
, M.Sc. Thesis Sharif University of Technology ; Haji, Alireza (Supervisor)
Abstract
Nowadays best using of fossil fuels sources of the country (and) importance of comparison against lack of capacity in petrol production make determined the programmers and the directors to foresee and design expanded programs of the goals, to use natural gas for car fuels. To reach fulfillment of these programs, the confirmed needs of the natural gas cylinders are improved and make it essential to invest on producing compressive natural gas cylinders. In this way economical and technical change researches has been done in order to construct on department to produce 200,000 compressive natural gas cylinders in a year during two sets.(shifts) According to the results of technical researches...
Synthesis, Characterization and Field Emission Study of Molybdenum Oxide (MoOx)Nanostructures
, M.Sc. Thesis Sharif University of Technology ; Moshfegh, Alireza (Supervisor)
Abstract
Different molybdenum oxide nano/micro structure thin films were synthesized by thermal evaporation method under various growth conditions such as deposition time, temperature and evaporation source-substrate distance. Molybdenum oxide nanostructures grown on Si(100) such as nanowalls, nanostars and nanowires were characterized with scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM). Shape and type of nanostructures were determined with SEM, AFM and HRTEM analysis. XPS analysis showed that the synthesized nanostructures contained Mo6+, Mo5+, Mo4+ and...
Identification and Abnormal Condition Detection of a Cement Rotary Kiln
, M.Sc. Thesis Sharif University of Technology ; Fatehi, Alireza (Supervisor)
Abstract
One of the most important parts of a cement factory is the cement rotary kiln which plays a key role in quality and quantity of produced cement. In this part, the physical exertion and bilateral movement of air and materials, together with chemical reactions take place. Thus, this system has immensely complex and nonlinear dynamic equations. These equations have not worked out yet. Only in exceptional case; however, a large number of the involved parameters were crossed out and an approximation model was presented instead. This issue caused many problems for designing a cement rotary kiln controller. In this thesis, we employed a nonlinear system identification method for identification,...
Entanglement and Decoherence in Optomechanical Systems Coupled through Photothermal Effects
, Ph.D. Dissertation Sharif University of Technology ; Bahrampour, Alireza (Supervisor)
Abstract
Optomechanical systems have attracted considerable attention in the last decade. Such a raising prominence is mainly due to its capability in providing new insight into the quantum behavior of macroscopic objects and exploring the interface between quantum and classical mechanics. Alongside this fundamental quest, cavity optomechanics has many other benefits, ranging from very precise measurements on forces and positions to quantum information processing. In this thesis, we investigate quantum properties of such systems. Particularly, we study cooling of the mechanical resonator toward its ground state and the entanglement between this mechanical resonator and the cavity field. Cooling the...
Improvement in Reinforced Concrete Beam-Column Connections Behaviour using FRP Sheets
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
Performance of reinforced concrete frames is highly dependent on detailing of the joint connections between its members, such as beams and columns. To have a good structural behavior, joints must show ductile behavior and designed based on the philosophy of strong column-weak beam. In the case of sever lacking ductility, strength or even rigidity of the connections, or having a weak column-strong beam, in the existing structures, there is a need for seismic upgrading of the connection. There are several ways for seismic upgrading of this type of connections.In the last decade Fiber Reinforced Polymer (FRP) widely has been used to strengthening the reinforced concrete (RC) members. Most of...
Hodge Theory on Metric Spaces
, M.Sc. Thesis Sharif University of Technology ; Bahraini, Alireza (Supervisor)
Abstract
Hodge theory is a beautiful synthesis of geometry, topology, and anal- ysis, which has been developed in the setting of Riemannian manifolds. On the other hand, spaces of images, which are important in the math- ematical foundations of vision and pattern recognition, do not fit this framework. This motivates us to develop a version of Hodge theory on metric spaces with a probability measure. We believe that this constitutes a step towards understanding the geometry of vision. We extend the theory of the Laplacian on domains of Euclidean space or on a manifold and next to metric space. Finally we give a beautiful application in web researcher engin.
Behran Mehr Peyma's Activities Analysis
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Alireza (Supervisor)
Abstract
Behran Mehr Peyma (BMP) is an elevator equipment producer and trader in Iran which was established in 2004. At first they are producing some regular parts of elevator and then during these years they are trying to improve their work and expand their business till they have the 15% market share in elevator market in Tehran.In this thesis I am trying to use the SWOT and PETS methods to show the exact situation of BMP comparing to the whole market considering the competitors.During this reduction in the market I suggest to BMP to change some policies and use some of its strength to attract some new customers, changing their brand name and find a relation to contribute in some tenders and...
Evaluating and Improving the Reliability of Reversible Adiabatic Logic Styles
, M.Sc. Thesis Sharif University of Technology ; Ejlali, Alireza (Supervisor)
Abstract
Adiabatic logic families are a group of logic circuits which operate based on adiabatic principles to tremendously reduce power consumption. These families have basic difference with common logic families in transistor level structure and there signals are not quadrangular but trapezoidal. Also, in these systems the source lines and clock pulse are the same. Research on Adiabatic families needs theoretical information in reversible computing. So we will start this project with explaining fundamental information in this field. After that some of these logic families are introduced and three important and widely used of them (SCRL-RERL-2LAL) are chosen to simulate. In each of these families...