Loading...
Search for: vafa--narges
0.118 seconds

    Synthesis and Characterization of Vanadium (IV)-SNO & ONO Tridentate Schiff-Base Complexes and Their Applications in Sulfide and Alcohol Oxidation in Ionic Liquid Media

    , M.Sc. Thesis Sharif University of Technology Mousavi, Narges Sadat (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    Abstract
    In recent years, application of transition metal biphasic catalytic systems for different reactions is an area of intense research activity. Among these reactions, oxidation of sulfides to sulfoxides and sulfones due to their importance as an intermediate in synthesis of organic compounds is a center of interest. Also, the catalytic conversion of alcohols to the corresponding aldehydes or ketones is a fundamental transformation in both laboratory and industrial synthetic chemistry. From environmental perspectives, the development of new catalytic oxidation systems with molecular oxygen as green oxidant is particularly attractive. In recent years, ionic liquids have been extensively studied... 

    Agent-based Programming and it's Application Using GOAL

    , M.Sc. Thesis Sharif University of Technology Hosseinian, Narges Sadat (Author) ; Ramezanian, Rasoul (Supervisor)
    Abstract
    With the significant advances in software engineering and developing complicated systems, it’s important to investigate the interaction between systems. Agentoriented software engineering is a new paradigm for developing distributed intelligent systems. Agent technology currently plays an important role in complex software development. The underlying paradigm offers a large repertoire of original concepts, architectures, interaction protocols, and methodologies for the analysis and the specification of complex systems built as Multi-Agent Systems (MAS). Several efforts, originating from academia, industry, and several standardisation consortium, have been made in order to provide new tools,... 

    Auto-selection of space-time Interest Points for Action Recognition
    Application in Fisherposes Method

    , M.Sc. Thesis Sharif University of Technology Ghojogh, Benyamin (Author) ; Mohammadzadeh, Narges Hoda (Supervisor)
    Abstract
    In this project, a novel action recognition method, named Fisherposes, is proposed, which is improved by several space-time (spatio-temporal) methods afterwards. The proposed method utilizes skeleton data obtained from Kinect sensor. First, pre-processing is performed in which the scales of bodies are canceled and the skeletons become aligned in order to make the method robust to location, orientation, and scale of people. In Fisherposes method, every action is defined as a sequence of body poses. Using the training samples for the poses, a Fisher subspace is created which we name it Fisherposes. Moreover, a novel distance measuring function, named regularized Mahalanobis distance, is... 

    Temporal Analysis of Functional Brain Connectivity Using EEG Signals

    , M.Sc. Thesis Sharif University of Technology Khazaei, Ensieh (Author) ; Mohammadzadeh, Narges Hoda (Supervisor)
    Abstract
    Human has different emotions such as happiness, sadness, anger, etc. Recognizing these emotions plays an important role in human-machine interface. Emotion recognition can be divided into approaches, physiological and non-physiological signals. Non-physiological signals include facial expressions, body gesture, and voice, and physiological signals include electroencephalograph (EEG), electrocardiograph (ECG), and functional magnetic resonance imaging (fMRI). EEG signal has been absorbed a lot of attention in emotion recognition because recording of EEG signal is easy and it is non-invasive. Analysis of connectivity and interaction between different areas of the brain can provide useful... 

    Null Controllability and Stabilizability of Compressible Navier-stokes System in One Dimension

    , M.Sc. Thesis Sharif University of Technology Hosseini Khajouei, Narges Sadat (Author) ; Hesaraki, Mahmoud (Supervisor)
    Abstract
    In this thesis we study the exponential stabilization of the one dimensional compressible Navier-Stokes system, in a bounded interval locally around a constant steady state by a localized distributed control acting only in the velocity equation. In fact this is an analysis of a paper that published by Shirshendu Chowdhury, Debayan Maity, Mithily Ramaswamy and Jean-Pierre Raymond in Journal of Differential Equations. We determine a linear feedback law able to stabilize a nonlinear transformed system. Coming back to the original nonlinear system, we obtain a nonlinear feedback law able to stabilize locally this nonlinear system. The result is providing feedback control laws stabilizing... 

    Study of the Current Status and Future Perspective of E-Commerce in IRAN

    , M.Sc. Thesis Sharif University of Technology Ghahramani, Abdolreza (Author) ; Moayedi, Vafa (Supervisor)
    Abstract
    The main purpose of my research is to present a predictive E-Commerce plan for Iran. For many people the term "electronic commerce" means shopping on the part of the Internet called the World Wide Web, but other technologies such as wireless transmissions on mobile telephone and personal digital assistant devices are also included. In our thesis the term Electronic Commerce or (E-Commerce) is used in its broadest sense, and includes all business activities conducted using electronic data transmission technologies. In Iran e-commerce has achieved an important role and is facing remarkable acceptance in trade operations, therefore my study focuses on the development of E-Commerce model in... 

    Evaluating the Effects of Operating Conditions on Particle Size and Molecular Weight Distributions in Emulsion Polymerization of Styrene

    , M.Sc. Thesis Sharif University of Technology Vafa, Ehsan (Author) ; Shahrokhi, Mohammad (Supervisor)
    Abstract
    In this work, a comprehensive dynamic model has been used for styrene emulsion polymerization in a semi-batch reactor to predict the evolution of product particle size and molecular weight distributions under non-isothermal condition. Method of moments has been applied for solving the population balance equations and the results are compared with the results obtained from finite-volume method as a precise technique. A sensitivity analysis respect to perturbation in initial values of various reagents, species and the reactor temperature has been performed to identify suitable manipulated variables for closed-loop control of the reactor. The detailed model is used to generate optimal feed... 

    Numerical Simulation of Discharged Liquid Jet from Desalination Plants and Investigation Mixing Characteristics with Surroundings

    , M.Sc. Thesis Sharif University of Technology Vafa, Narges (Author) ; Firoozabadi, Bahar (Supervisor)
    Abstract
    Today, due to the decline of drinkable water, many desalination plants have been established and operated around the world. Disposal of these brines, which have higher density and temperature than receiving water, causes many environmental impacts. Industrial power plants discharge these effluents into the seawater body mostly as submerged jets due to their higher effectiveness. Many experimental researches have been done on the negative and positive buoyant jet that discharged form desalination plants. But a few numerical studies have been done with investigating the full Navior-Stokes equations and they have been flawed in modeling. For example, some of these models have been able to... 

    Control Structure Design of Process Systems with Recycle and Purge

    , M.Sc. Thesis Sharif University of Technology Abareshi, Mehdi (Author) ; Vafa, Ehsan (Supervisor)
    Abstract
    In this research, self-optimizing method has been used to design a plant-wide control structure for processes containing purge and recycle streams. The method is based on the concept of self-optimizing variables to maximize the process profitability in the presence of possible disturbances. The purpose of this thesis is to perform this procedure on ammonia and methanol processes containing purge and recycle streams.Using the results obtained for the ammonia process and considering the constraints and operating conditions of the problem, the active constraints of this process were detected which were cooling water flow rates to exchangers. According to local analysis method, self-optimizing... 

    Dynamic Simulation and Control of Anaerobic Photo-Bioreactors Using Purple Phototropic Bacteria in Wastewater Treatment Applications

    , M.Sc. Thesis Sharif University of Technology Nasaji, Amin (Author) ; Vafa، Ehsan (Supervisor)
    Abstract
    Purple phototropic bacteria (PPB) are a potential mechanism for wastewater treatment and recovering materials. Purple phototropic bacteria is one of the microorganisms that use infrared light energy and carbon contained in volatile fatty acids (VFA), in addition to eliminating nitrogenous compounds, it has a high ability to recover nutrients in wastewater. In this project, a photobioreactor is investigated, in which the purple phototropic bacteria by absorbing nutrients (phosphate and nitrate) and substances present in the wastewater, provides the possibility of releasing these substances in the open environment without the environmental hazards. The mathematical modeling and control of this... 

    Simulation, Control and Dynamic Process Intensification of Heat Integrated Binary Distillation Columns

    , M.Sc. Thesis Sharif University of Technology Parvin, Mahan (Author) ; Vafa, Ehsan (Supervisor)
    Abstract
    In light of rising energy costs and restricted access to energy resources, enhancing energy efficiency in process industries has become increasingly important. One effective method for reducing energy consumption in chemical industries is the use of thermal integration in distillation columns. This study examines the thermal integration of a benzene-toluene distillation column with the aim of analyzing and improving energy performance from a dynamic intensification perspective. Initially, the internal thermal integration of the distillation column was modeled. Subsequently, a mathematical analysis of the model was conducted to identify conditions of multiplicity. Following this, steady-state... 

    Economic Model Predictive Control of a Multiproduct CSTR Based on Elementary Reactions

    , M.Sc. Thesis Sharif University of Technology Soofi, Vahid (Author) ; Vafa, Ehsan (Supervisor)
    Abstract
    One of the model based control strategies that has been proposed in recent years for the control of process systems is the one based on the economic models, in which objective functions with an economic basis are used along with the equations and constraints to perform control calculations. In this work, the control of a multiproduct continuous stirred reactors is discussed, in which, it is possible to produce different products based on changes in the market demand, the price of the products or the primary raw materials according to a specific schedule. One of the recently used methods is the economic predictive control method based on the Lyapunov function. In this method a quadratic... 

    Investigation of Modeling and Simulation of Particle Size Distribution in Pickering Emulsion Polymerization

    , M.Sc. Thesis Sharif University of Technology Parsaniya, Reza (Author) ; Vafa, Ehsan (Supervisor)
    Abstract
    Emulsion polymerization is a multiphase process which produces dispersions of polymeric particles in water called polymeric latexes. When instead of surfactants solid particles stabilize the latex, the process is called Pickering emulsion polymerization. Latexes produced in this way exhibit better mechanical and optical properties. In this work, a model for styrene Pickering emulsion polymerization in the presence of Laponite RDS given in the literature was simulated. The results of simulation were unsatisfactory. A procedure was developed to separately check different parts of the code which was written for the task. Also, another emulsion polymerization system, in which the monomer was... 

    Conditions for Optimum Team Performance: An Empirical Research

    , M.Sc. Thesis Sharif University of Technology Rahanjam, Saeed (Author) ; Moayedi, Vafa (Supervisor)
    Abstract
    In today’s business world, team working as one of the most useful solutions to improve organizational performance and efficiency is used by different organizations and companies. Many experts and academic researchers are focused on teams and team based organizations in their studies and tried to find its cause and effect on organizational performance in the past two decades. Also different variables are recommended as influencing factor on team performance by different authors, In spite of all these researches, no fixed list of these factors, which are been acceptable by reasonable number of researchers and experts, can be find yet. This study tries to present the results of an experimental... 

    Enhancing Energy Efficiency in Ideal Binary Distillation tower with a Dynamic Process Intensification

    , M.Sc. Thesis Sharif University of Technology Hosseinpour, Ali (Author) ; Vafa, Ehsan (Supervisor)
    Abstract
    In this thesis titled "Enhancing Energy Efficiency in Ideal Binary Distillation tower with a Dynamic Process Intensification," operational methods in distillation units are explored and improved. Given the high cost of energy, limited energy resources, and environmental considerations, increasing energy efficiency in process industries has become significantly important. In this context, this research attempts to enhance the performance of the distillation unit by utilizing dynamic process intensification with two operational points corresponding to the production of products with purities both higher and lower than the desired product purity, and switching between these two points. The... 

    Software Product Line Testing Optimization Based on Regression Test Techniques

    , M.Sc. Thesis Sharif University of Technology Mousavi Khoshdel, Narges Sadat (Author) ; Mirian Hosseinabadi, Hassan (Supervisor)
    Abstract
    A software product line is a set of products with common features. The design of this set is such that the core assets that are common features between products are implemented only once. All products in the product line use the core assets to reduce development costs. The number of products that can be produced in a software product line is exponential to the number of capabilities in the core assets and the set is very large, so the cost of testing the software product line will be very high. In the software product line testing, various methods have been provided to reduce costs, among which we can mention product prioritization and regression test techniques. In prioritization, the... 

    Analysis of People Appearance Variation in Multi-Camera Networks

    , M.Sc. Thesis Sharif University of Technology Moradipour, Mostafa (Author) ; Behroozi, Hamid (Supervisor) ; Mohammadzadeh, Narges Hoda (Co-Supervisor)
    Abstract
    Analysis of people appearance variation in multi-camera networks for person re-identification or person retrieval is a very challenging problem due to the many intra-class variations between different cameras. Like any problem in the field of machine vision, it is generally divided into two parts. The first part is feature extraction and the second part is feature matching for person retrieval. So far, various methods have been proposed for the extraction of discriminative features, which are generally divided into three categories: stripe-based, patch-based, and body-based methods. However, methods based on stripes, although simpler, have performed better due to their greater compatibility... 

    Solution of population balance equations in emulsion polymerization using method of moments

    , Article Chemical Engineering Communications ; Volume 200, Issue 1 , 2013 , Pages 20-49 ; 00986445 (ISSN) Vafa, E ; Shahrokhi, M ; Abedini, H ; Sharif University of Technology
    2013
    Abstract
    In this work, the method of moments is used for solution of population balance equations appearing in modeling of emulsion polymerization (EP). The zero-one model without coagulation effect and the pseudo-bulk model including coagulation effect are investigated as two common approaches for modeling EP processes. The fixed quadrature method is used to close the set of moment equations, and the maximum entropy approach is applied to reconstruct the particle size distribution from a finite number of its moments. Comparing the results with those obtained by the high-precision finite volume technique indicates that, despite the low computational load of the moment method, it has an acceptable... 

    Inferential closed-loop control of particle size and molecular weight distribution in emulsion polymerization of styrene

    , Article Polymer Engineering and Science ; Volume 50, Issue 12 , 2010 , Pages 2306-2320 ; 00323888 (ISSN) Vafa, E ; Shahrokhi, M ; Abedini, H ; Sharif University of Technology
    2010
    Abstract
    In this work, simultaneous inferential control of particle size distribution (PSD) and molecular weight distribution (MWD) in a semi-batch emulsion polymerization reactor of styrene has been addressed. Using a comprehensive dynamic model for PSD and MWD predictions and performing a sensitivity analysis, it has been revealed that free surfactant and chain transfer agent (CTA) concentrations in the reactor are the most suitable candidates for inferential control of PSD and MWD, respectively. To control concentrations of these species in the reactor, their inlet feed flow rates are used as manipulated variables. It is assumed that the concentration of CTA is measured infrequently and therefore... 

    The Effect of Subsidy Removals on Iran's Economy

    , M.Sc. Thesis Sharif University of Technology Asghari Roodsari, Azadeh (Author) ; Moayedi, Vafa (Supervisor)
    Abstract
    After years of disputes on one of the most important challenges in our national economy, finally in Dey 1388 (January 5, 2010) the “Targeted Subsidies Law” was passed by the Iranian parliament. Based on this law, all fiscal (explicit) and quasi-fiscal (implicit) subsidies for goods and services will be removed from the government’s general budget and redistributed among public with a different system. Implementation of the Targeted Subsidies Plan legislation as one of the important decisions in Iran’s economy has widely gotten the attention of economists, scientists and policymakers at industries, universities and other governmental sectors. Firms and other economic actors such as producers...