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batmanghelich--farhad
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Electrophoretic Deposition of Chitosan- Hydroxyapatite- Multiwalled Carbon Nanotube Composite Coatings
, M.Sc. Thesis Sharif University of Technology ; Ghorbani, Mohammad (Supervisor)
Abstract
At the first stage, chitosan-hydroxyapatite-multiwalled carbon nanotube (CH-HA-MWCNT) composite coatings were synthesized by electrophoretic deposition technique (EPD) on Ti6Al4V and 316L stainless steel substrates at different levels of pH and characterized by X-ray diffraction (XRD), Raman spectroscopy, FTIR and field emission scanning electron microscopy (FESEM). A smooth distribution of HA and MWCNT particles in a chitosan matrix with strong interfacial bonding was obtained. At the second stage, effect of pH and MWCNT content of the suspension on corrosion behavior and mechanism of deposition were studied. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS)...
Effect of pH and carbon nanotube content on the corrosion behavior of electrophoretically deposited chitosan-hydroxyapatite-carbon nanotube composite coatings
, Article Ceramics International ; Volume 39, Issue 5 , July , 2013 , Pages 5393-5402 ; 02728842 (ISSN) ; Ghorbani, M ; Sharif University of Technology
2013
Abstract
In the first stage, chitosan (CH)-hydroxyapatite (HA)-multiwalled carbon nanotube (MWCNT) composite coatings were synthesized by electrophoretic deposition technique (EPD) on 316L stainless steel substrates at different levels of pH and characterized by X-ray diffraction (XRD), Raman spectroscopy, FTIR and field emission scanning electron microscopy (FESEM). A smooth distribution of HA and MWCNT particles in a chitosan matrix with strong interfacial bonding was obtained. In the next stage, effects of pH and MWCNT content of the suspension on the corrosion behavior and deposition mechanism were studied. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) curves...
Synthesis, Characterization, Structure Determination and Theoretical Studies of Some New Dimethylglyoxime Cobalt (ΙII) Complexes
, M.Sc. Thesis Sharif University of Technology ; Kia, Reza (Supervisor)
Abstract
In this study, a number of complex cobaloxim complexes [Co(DMG)2LX] in which L= 4-MePy, 3-MePy, 4-bzPy, 3-CNPy, 4-CNPy, tBuPy, styPy, NaphPy synthesized and their structure studied. These complexes were identified by FT-IR and 1H NMR methods as well as their solid state structure studied by X-ray crystallography of single crystals. Gaussian 09 software was used to optimize the geometric structure and obtain the vibrational frequency of cobalt complexes. Charge decomposition Analysis (CDA) and molecular orbital studies were performed using the AOMix 6.88 software. Also, the characterization of σ-donating and П-acceptoring of pyridine ligands in these complexes was investigated using...
Corrosion and time dependent passivation of Al 5052 in the presence of H2O2
, Article Metals and Materials International ; Volume 22, Issue 4 , 2016 , Pages 609-620 ; 15989623 (ISSN) ; Bagheri Hariri, M ; Sharifi Asl, S ; Yaghoubinezhad, Y ; Mortazavi, G ; Seo, Y ; Sharif University of Technology
Korean Institute of Metals and Materials
2016
Abstract
Corrosion and time–dependent oxide film growth on AA5052 Aluminum alloy in 0.25M Na2SO4 solution containing H2O2 was studied using electrochemical impedance spectroscopy, potentiodynamic polarization, chronoamperometric and open circuit potential monitoring. It was found that sequential addition of H2O2 provokes passivation of AA5052 which ultimately thickens the oxide film and brings slower corrosion rates for AA5052. H2O2 facilitates kinetics of oxide film growth on AA 5052 at 25° and 60 °C which is indicative of formation of a thick barrier film that leads to an increment in the charge transfer resistance. Pitting incubation time increases by introduction of H2O2 accompanied by lower...
Development of Continuous Kinetic Model for Visbreaking of Heavy Oil Cuts
,
M.Sc. Thesis
Sharif University of Technology
;
Khorashe, Farhad
(Supervisor)
Abstract
In this study the kinetic modeling of visbreaking reactions of heavy oils was investigated using available experimental data from the literatures. The continuous lumping model was developed for kinetic analysis of visbreaking reactions. The normalized boiling point was used to describe the reactant mixture as a continuous mixture and the concentration distribution of the mixture would change under reaction conditions. The continuous model with five adjustable parameters was used to describe visbreaking reactions and these parameters were optimized for each feed and reaction temperatures in the range of 400 to 430ºC using the available experimental data. Therefore for a special feed in a...
Modeling of Side Reactions in Propane Dehydrogenation Over Pt-Sn/γ-Al2O3 Catalyst
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor)
Abstract
The kinetics of side reactions in dehydrogenation of propane over a supported platinum catalyst modified by tin was investigated. Catalytic dehydrogenation over a commercial Pt-Sn/γ-Al2O3 was carried out in a laboratory-scale plug-flow reactor at 580 to 620oC under atmospheric pressure. Several kinetic models derived from different reaction mechanisms were tested using experimental data obtained over a range of reaction conditions. It was found that the kinetics of the main dehydrogenation reaction was best described in terms of a Langmuir-Hinshelwood mechanism where adsorption of propane was the rate controlling step. Simple power low rate expressions were used to express the kinetics of...
Foreign Exchange Rate Forecasting In Global Money Markets Using Adaptive Methods
, M.Sc. Thesis Sharif University of Technology ; Kianfar, Farhad (Supervisor)
Abstract
The traders exchange currencies in an online foreign exchange market (Forex), so they need to know ways help them to predict trend of market. There are some methods to forecast exchange rate based on experiment. However they can submit good signals, they are too late for exchange. Two things are important, they should be correct and on time. In this research, we try to submit a prediction by Adaptive Methods in which provides both of them. In first approach, we test 468 models of Artificial Neural Network to achieve the best; and in second approach, Genetic Algorithm and Swarm Intelligence are applied to training Artificial Neural Network. Finally, in addition to forecasting exchange rate,...
Investigation of Removing Idiosyncratic Price Distortions On Manufacturing TFP in Iran
, M.Sc. Thesis Sharif University of Technology ; Nili, Farhad (Supervisor)
Abstract
Government intervention in markets may go beyond the market regulation. Interventions may cause some idiosyncratic price distortions. It means the relative prices of factors to become different among firms. Therefore, micro conditions for firms will be changed. These will result in misallocation of factor production between firms and change in manufacturing TFP. According to data from about 14000 medium and small industrial firms in Iran, removing misallocation of production factors (capital and energy) and output idiosyncratic distortions between industrial firms would result in 115 percent increase in manufacturing TFP.
Using Optimal Control for Dynamic Pricing under Learning Effect of Supply and Demand
, M.Sc. Thesis Sharif University of Technology ; Kianfar, Farhad (Supervisor)
Abstract
In this research a monopolist is considered which its object is maximization of profit during a predetermined period. Optimal control theory is used as a tool for determining of optimal trend for control variables. Price, warranty length and production rate are considered as control variables and cumulative demand and production are considered as state variables. Learning effect in production side and demand side are entered in the model too. In the demand side, learning effect shows its influences with movement of market from diffusion phase to saturation phase. In diffusion phase the demanded quantity of productions increases by increase of cumulative demand, on the contrary in the...
A New Metaheuristic Algorithm Based on Particle Swarm Optimization for Discrete Time Resource Trade-off Problem
, M.Sc. Thesis Sharif University of Technology ; Kianfar, Farhad (Supervisor)
Abstract
In this research, a new metaheuristic algorithm is developed for solving the Discrete Time- Resource Trade off Problem in the field of project scheduling.In this problem ,a project contains activities interrelated by finish-start type precedence constraints and each has a specified work content and can be performed in different combinations of duration and resource requirement.Since the problem is NP-hard , the Particle Swarm Optimization is adopted due to minimization of the makespan subject to precedence relations and a single renewable resource. Basically PSO is used to solve continous problems and discrete problems have just begun to be solved by the discrete PSO.In proposed method,a...
The Comparative Study of Nanotechnology Research and Development in The World Selected Countries
, M.Sc. Thesis Sharif University of Technology ; Ghasemi, Farhad (Supervisor)
Abstract
Nanotechnology requires a number of infrastructures for reaching its sustainable development. For each step of its development , various infrastructures should be studied and prepared in advance.In this direction, by introducing and recognizing the priority of Iran Nanotechnology R&D indexes ,the present research is going to propose an effective help. In this case, after studying the related literature and gathering the needed data , 27 indexes were recognized. Then , the indexes were divided in 7 criteria.In order to find the priority of the applied indexes , Fuzzy Multiple Criteria Decision Making (FMCDM) was applied. As the weighting of 7 criteria had been found by FANP , the...
Kinetic Modeling of Coke Formation in PDH over Pt-Sn/Al2O3 in Presence of Oxygenated Additives
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor)
Abstract
Propylene, as one of the most important raw materials of petrochemical industries, is produced through different methods. One of the major methods is propane dehydrogenation. This reaction is endothermic and many by-products will be produced in high temperature. Therefore catalytic dehydrogenation is preferred. Reduction in catalyst's activity and too many side reactions are the most important problems. Coke formation is the most effective reason of deactivation. Main source of coke is propylene. Experiments show that very small amount of water presence within reaction can reduce rate of coke formation. Water content growth does not always increase activity. If water be more than optimum...
Kinetic Modeling of Propane Dehydrogenation on Industrial Pt-Sn/γ-Al2O3 in Presence of Oxygenated Compounds
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor)
Abstract
The study on the propane dehydrogenation process has been receiving significant attention due to the growing demand for propylene. The aim of this research is to develop an appropriate kinetic mechanism for dehydrogenation of propane over an industrial Pt–Sn/γ-Al2O3 catalyst in the presence of a very small amount of water. The reaction is carried out over the temperature range of 575 – 620 º C at atmospheric pressure. The results showed that a small amount of water and methanol can improve the performance of catalyst and also, increase the selectivity to COx. Addition the 0.5, 0.45, 0.3 water and 0.1, 0.05, 0.02 methanol are the optimum amount of these oxygenated compounds in order at...
Risk Management and Cash Flow In Banks
, M.Sc. Thesis Sharif University of Technology ; Kianfar, Farhad (Supervisor)
Abstract
Asset and liability management is a method for optimizing cash flows of input and output of a bank . The model for optimizing the balance between liability and assets of a bank is presented in this research. Bank asset liability management and planning can be considered at the same time. In tjis model , all assets and liabilities in the bank balance sheet are discussed under different objectives and requirements , such as legal and administrate requirements, market condition, risk rate etc
Measurement of the B-Tagging Efficiency in the CMS Experiment with the First LHC Collisions
, Ph.D. Dissertation Sharif University of Technology ; Ardalan, Farhad (Supervisor)
Abstract
Jets originating from bottom (b) quarks, play an important role in the study of Standard Model processes together with the search for new physics. In the CMS experiment a considerable e?ort is dedicated to the development and the performance study of so-called b-tagging algorithms. On the other hand, the top quark which is produced in pair (tt¯) with a high rate at the LHC, decays near 99% of the time to a b-quark. Hence it provides a rich source of b-quark jets, suitable for b-jet identi?cation studies. In this thesis, a fully data-driven method to measure the b-tagging e?ciency, using top quark events in its semi-electron ?nal state, is developed. The results of the application of the...
Kinetic Modeling of Hydrocracking of Synthetic Wax from Fischer-Tropsch
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor)
Abstract
Fischer-Tropsch process (FT ) is one of the most important processes gas-to-liquid (GTL) conversion. This process converts synthesis gas into hydrocarbons. Depending on the catalyst and operating conditions of the process, heavy paraffins (Wax) are the most important products in this process. These products can be used to heavy paraffin catalyst hydrocracking in a process for the production of diesel fuel and gasoline to lighter products are suitable to be converted. The aim of this project is to develop a suitable kinetic model to describe the process of producing heavy paraffin hydrocracking process Fisher - Tropsch to be lighter products. In this regard, each 5 continuous mass model...
A Model for Hierarchical Production Planning in a Make-to-order System
,
M.Sc. Thesis
Sharif University of Technology
;
Kianfar, Farhad
(Supervisor)
Abstract
A hierarchical production system in make-to-order environment is presented in this thesis. This production system is consisted of three different decision making levels. Maximum acceptance for production within customer specified time interval was done in the first stage, which is called order arriving stage, based on different client criteria, type of demanded product, and production system constraints. A new hierarchical decision making structure for accepting or rejecting arriving orders is proposed in this level. The output of this acceptance level is orders having maximum production system defined criteria, and minimum production cost along with order delivery time with minimum delay is...
Using Decision Analysis Concept to Implement Variant Process Planning System
, M.Sc. Thesis Sharif University of Technology ; Kianfar, Farhad (Supervisor)
Abstract
In Computer-Aided Process Planning, there are two ways of manufacturing called Variant Manufacturing and Generative Manufacturing. Variant Manufacturing is based on a data base from a part family for a project. The part family is made in a series of root sheets regarding the final form of the intended part. The data base is updated after the manufacturing of each part. In order to make the system intelligent, one can use the OPITZ coding system that specifies the geometrical form, geometrical details and part manufacturing operations in a 13-digit number. The aim of this research is to choose the best machining parameters according to time and cost, that, based on the basic principles of...
Multi-period Project Portfolio Selection and Scheduling with Uncertainties
, Ph.D. Dissertation Sharif University of Technology ; Kianfar, Farhad (Supervisor)
Abstract
In this thesis, a multi-stage project portfolio selection and scheduling problem in an uncertain environment is modeled, analyzed and solved. Moreover, we investigate the situations in which a project manager is confronted to a large number of projects to be selected and scheduled while the required resources of the projects are limited and renewable. The aim is to maximize objective function which is the net present value of the profit of the projects. To solve the mentioned problem, we introduce a multi-stage stochastic programming. For the reason that, in real problems, optimization problems that included all restraints are large scale and have computational complexity, these problems are...
Using Time Series and Planning Uncertain Demand in Supply Chain with System Dynamics Approach
, M.Sc. Thesis Sharif University of Technology ; Kianfar, Farhad (Supervisor)
Abstract
In the field of supply chain, management constantly seeks to adopt strategies for realizing its targeted objectives. The supply chain, therefore, includes integrated production-distribution processes with all effective parts where proper management requires a comprehensive and dynamic approach. It is necessary to meet required items at required time. This becomes more important with the supply systems providing items. On the other hand, the difficulty of supply chain management, decisions, and policy-making can be increased by a wide range of conditions such as changes in demand. Thus, a comprehensive approach is needed to take the present dynamics into account. The current paper develops a...