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    Application of Membrane Distillation Technology for Treating Saline Water of Sarcheshme Copper Refinery

    , M.Sc. Thesis Sharif University of Technology Mahmoodi Meymand, Negar (Author) ; Shaygan, Jalaleddin (Supervisor)
    Abstract
    Sarcheshme Copper refinery is using ion exchange columns to supply deionized water to the refinery. Every day, 240 cubic meters of waste water from ion exchange columns process are released in nature. The main purpose of this research is to use membrane distillation to purify this wastewater, which reduces the fresh water requirement and at the same time prevents environmental pollution. Membrane distillation technology is capable to purify the high salinity wastewater that other conventional membrane technologies are not able to purify. In this study, the PTFE membrane was used due to its high permeability and low surface energy with pore size of 0.22 μm and membrane thickness of 0.2 to... 

    Modeling and Control of a Fish Robotic System Using Hardware in the Loop Methodology

    , M.Sc. Thesis Sharif University of Technology Zeinoddini Meymand, Sajjad (Author) ; Vossoughi, Gholamreza (Supervisor)
    Abstract
    In the present study, an adaptive sliding mode control method was employed to control a fish robotic system using the method of hardware in the loop. Following the introduction of the nonlinear model for the robot, elongated body theory, suggested by Lighthill, was used to analyze fish movements. Lighthill’s theory inspired from slender body theory in aerodynamics scope could be viable to exercise upon the carangiform mode of swimming. By simplifying Lighthill’s equations in planar motion of fish robot, the number of degrees of freedom exceeds the number of the control variables. In view of the fact that the presented model is an under-actuated model, there exist some parametric and... 

    Transportation Energy Consumption Patterns in Iran Cities: The Interplay of Urban Expansion, Population Density and Gasoline Subsidy

    , M.Sc. Thesis Sharif University of Technology Ghasemi Meymand, Mohammad Hadi (Author) ; Mirnezami, Reza (Supervisor)
    Abstract
    All studies conducted in this field have been carried out in developed countries, yielding unique and diverse finding. These differences in results stem from the varying transportation approaches of each country, leading to entirely different policy recommendation. Therefore, these research aims to analyze urban transportation energy consumption patterns in Iran, a country with distinctive approaches to energy consumption in transportation and urbanization. This study gathers data from 80 Iranian cities over 10-year period, defining dependent, independent and control variables, and employ multiple regression analysis alongside the optimal model to derive conclusion. The findings indicate... 

    Hardware in the loop simulation and analysis of a model of fish robotic system

    , Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 5 , 2010 , Pages 203-210 ; 9780791849194 (ISBN) Zeinoddini Meymand, S ; Vosoughi, G. R ; Farshchi, M ; Nemati, A ; Sharif University of Technology
    2010
    Abstract
    In the present study, an adaptive sliding mode control method was employed to control a fish robotic system using hardware in the loop methodology. Up to now, few researches have focused on autonomous control of fish robot in dynamic environments which may be the result of difficulties in modeling of hydrodynamic effects on fish robot. Therefore, following the introduction of the nonlinear model for the robot, elongated body theory, suggested by Lighthill, was used to analyze fish movements. Then, kinematics control to track desired trajectories was designed for under-actuated model of robot. Adaptive sliding mode controller, capable of adapting according to changes and uncertainties, was... 

    The Impact of International Sanctions on the Stock Market of Iran, Using Automated Content Analysis Methods

    , M.Sc. Thesis Sharif University of Technology Mahmoudi Meymand, Mohammad (Author) ; Barakchian, Mahdi (Supervisor) ; Ebrahimnejad, Ali (Supervisor)
    Abstract
    In this study, we provide a detailed analysis of the Iranian stock market, in particular, the impacts of the recent sanctions imposed on this country. We develop a novel economics concept, sanction-index, to measure the effect of sanctions on the Iranian stock market. We utilize a set of principled approach on news analysis and automated content analysis methods and construct an extensive dataset using over a decade of World Economics newspaper, from 2009 to2019. This newsletter is a highly celebrated and most influential newspaper in the Iranian stock market society. Employing this dataset, we search over sanctions-related keywords to identify sanctions-related articles from the set of all... 

    Price competition in duopoly supply chains with stochastic demand [electronic resource]

    , Article Journal Of Manufacturing Systems ; 01/2014 Mahmoodi, A. (Anvar) ; Eshghi, Kourosh ; Sharif University of Technology
    Abstract
    In the literature, substantial researches have been carried out on supply chain coordination. The majority of these studies suggest a mechanism that enforces the supply chain members to follow the strategies that produce the equilibrium of an integrated supply chain. Moreover, most of researches do not consider the competition among supply chains  

    Synthesis of Ni-Co-CNT nanocomposite and evaluation of its photocatalytic dye (Reactive red 120) degradation ability using response surface methodology

    , Article Desalination and Water Treatment ; Volume 216 , 2021 , Pages 389-400 ; 19443994 (ISSN) Shokrgozar, A ; Seifpanahi Shabani, K ; Mahmoodi, B ; Mahmoodi, N. M ; Khorasheh, F ; Baghalha, M ; Sharif University of Technology
    Desalination Publications  2021
    Abstract
    Herein, NiO and Co2 O3, NiCo2 O4, and NiCo2 O4 /multi-walled carbon nanotubes nanocomposite were synthesized by the hydrothermal method and characterized by scanning electron micros-copy, energy dispersive spectroscopy, and X-ray diffraction. The photocatalytic activity of the synthesized materials was evaluated by Reactive Red 120 dye degradation. The photocatalytic activity of NiO and Co3 O4 was enhanced not only by the formation of NiCo2 O4, but also by its interaction with the functionalized multiwall carbon nanotubes support. The response surface methodology (RSM) was used to obtain the optimum parameters, including catalyst dosage, initial dye concen-tration, and pH on the dye... 

    , M.Sc. Thesis Sharif University of Technology Mahmoodi, Anwar (Author) ; Eshghi, Kourosh (Supervisor)
    Abstract
    In literature, substantial works have been done on supply chain coordination. The majority of these works looking for a mechanism that enforces the supply chain members to follow strategies that produce the equilibria of an integrated supply chain, and most of this literature ignores competition between supply chains. In this thesis, we consider two distinct supply chains which compete to each other on the price. We present a method to calculate the equilibria for three structural forms. In the first form, two supply chains are integrated and in the second form, one of the supply chains is integrated and the other one is decentralized. Finally in the third form, both supply chains are... 

    Evaluation and Simulation of Tunnel Mid-shaft Effects on the Natural and Normal Ventilation Performance in a Subway Tunnel

    , M.Sc. Thesis Sharif University of Technology Mahmoodi, Ghasem (Author) ; Farhanieh, Bijan (Supervisor)
    Abstract
    Necessity of a public transport network, environmental protection and a highly land cost in urban areas have increased the desire for underground transportation systems. On the other hand, ventilation system design should be done precisely specially for longer tunnels, large undergrounds spaces and crowded places. Rate of energy reduction for vent systems operation is dependent on their proper implementation. Tunnel design efficiently is influenced by ventilation system. The tunnel mid shaft is complementary part of the underground railway systems that is required for exchange air between the tunnel and the railway station with ambient fresh air. An important application of the tunnel mid... 

    Proposing a Control Method for Influenza Disease

    , M.Sc. Thesis Sharif University of Technology Mahmoodi, Marjan (Author) ; Shahrokhi, Mohammad (Supervisor)
    Abstract
    Immediate control of pandemic influenza to avoid casualties and financial losses is an important issue. In this thesis, two types of controllers including optimal controller and adaptive generalized predictive controller based on linear input-output model, with vaccine, treatment and quarantine being controlling variables, have been used to control influenza. Each controlling methods were investigated for different states including single-input single-output and multi-input single-output. Single-input single-output and multi-input single-output models are identified as online and offline using least squares method. Since it is difficult to exactly identify the model parameters, especially at... 

    Investigating the Use of Gold Nanoparticle in Increasing Dose of Tumor and Reducing the Dose of Normal Tissue in Brachytherapy

    , M.Sc. Thesis Sharif University of Technology Mahmoodi, Monireh (Author) ; Hosseini, Abolfazl (Supervisor)
    Abstract
    Over the past few decades, brachytherapy has been used as one of the leading methods in the treatment of a wide range of cancers, including breast cancer. Due to the high dose gradient of brachytherapy radiation sources, this method is used to treat such tumors that are grown at the vicinity of sensitive points or tissues of the body. Therefore, as irradiation get started by implanting radiation sources in the desired position, at the same time healthy tissue are also receiving the same dose as tumor tissues do Reducing healthy tissue dose along with increasing the dose of tumor tissue is one of the challenging topics that researchers are always looking for a solution. In the left breast... 

    Sodium hypochlorite-Dowex 1X8-200: A convenient oxidizing reagant

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 21, Issue 2 , 2002 , Pages 71-73 ; 10219986 (ISSN) Mahmoodi Hashemi, M ; Ahmadibeni, Y ; Sharif University of Technology
    2002
    Abstract
    The polymer supported hypochlorite ion is a facile selective oxidizing agent for the oxidation of various alcohols to aldehydes and ketones. Similarly it successfully oxidizes various Hantzsch type 1,4 - dihydropyridines to corresponding pyridines  

    Facile, Efficient and Low Cost Synthesis of N-(1H-imidazoline-2-yl)-1H-Benzimidazol-2-Amine and its Derivatives

    , M.Sc. Thesis Sharif University of Technology (Author) ; Mahmoodi Hashemi, Mohammed (Supervisor)
    Abstract
    Benzimidazoles are a bioactive family of chemicals which had been subject of many studies because of their valuable properties, and has a long history of production in chemical industries. Investigation on their properties and reactions with goal of achieving to new derivatives have drawn attention of many research teams. Recently, 2- Imidazolineaminobenzimidazole had been synthesized by microwave-assisted reaction of 2-Aminobenzimidazole with 2-Methylsulfanylimidazoline hydrogen iodide. But because of difficulties aroused by use of microwave system and expensive chemicals, we decided to utilized reaction procedures which could be facile, inexpensive with capability of high reaction scales.... 

    On edge star sets in trees

    , Article Discrete Mathematics ; Volume 311, Issue 13 , July , 2011 , Pages 1172-1178 ; 0012365X (ISSN) Akbari, S ; Ghorbani, E ; Mahmoodi, A ; Sharif University of Technology
    2011
    Abstract
    Let A be a Hermitian matrix whose graph is G (i.e. there is an edge between the vertices i and j in G if and only if the (i,j) entry of A is non-zero). Let λ be an eigenvalue of A with multiplicity mA(λ). An edge e=ij is said to be Parter (resp., neutral, downer) for λ,A if mA(λ)-mA-e(λ) is negative (resp., 0, positive ), where A-e is the matrix resulting from making the (i,j) and (j,i) entries of A zero. For a tree T with adjacency matrix A a subset S of the edge set of G is called an edge star set for an eigenvalue λ of A, if |S|=mA(λ) and A-S has no eigenvalue λ. In this paper the existence of downer edges and edge star sets for non-zero eigenvalues of the adjacency matrix of a tree is... 

    Nowhere-zero eigenvectors of graphs

    , Article Linear and Multilinear Algebra ; Volume 61, Issue 2 , 2013 , Pages 273-279 ; 03081087 (ISSN) Akbari, S ; Ghorbani, E ; Mahmoodi, A ; Sharif University of Technology
    2013
    Abstract
    A vector is called nowhere-zero if it has no zero entry. In this article we search for graphs with nowhere-zero eigenvectors. We prove that distance-regular graphs and vertex-transitive graphs have nowhere-zero eigenvectors for all of their eigenvalues and edge-transitive graphs have nowhere-zero eigenvectors for all non-zero eigenvalues. Among other results, it is shown that a graph with three distinct eigenvalues has a nowhere-zero eigenvector for its smallest eigenvalue  

    A certificate-based proxy signature with message recovery without bilinear pairing

    , Article Security and Communication Networks ; Volume 9, Issue 18 , 2016 , Pages 4983-4991 ; 19390114 (ISSN) Mahmoodi, A ; Mohajery, J ; Salmasizadeh, M ; Sharif University of Technology
    John Wiley and Sons Inc  2016
    Abstract
    In this paper, we propose the first provable secure certificate-based proxy signature (CBPS) with message recovery without bilinear pairing. In 2003, Gentry introduced the concept of certificate-based cryptography to solve certificate management and key escrow problems in public key infrastructure and identity-based cryptosystems, respectively. Because the overall cost of pairing computation is higher than scalar multiplication (e.g., over elliptic curve group), consequently, the CBPS schemes without pairings would be more efficient. According to the available research in this regard, our scheme is the first provable secure CBPS scheme with message recovery that is based on the elliptic... 

    One for one period policy for perishable inventory

    , Article Computers and Industrial Engineering ; Volume 79 , January , 2015 , Pages 10-17 ; 03608352 (ISSN) Mahmoodi, A ; Haji, A ; Haji, R ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    Recently, for zero ordering cost a new ordering policy named (1, T), in which the time interval between two consecutive orders and the value of the order size are both constant, have been developed for nonperishable products. In this paper, the (1, T) policy is developed for perishable products. Using an analogy among this inventory model, a queueing model with impatient customers, and a finite dam model, the long-run average total cost function of the inventory system is derived. It is observed that the total cost rate is independent from the lead time as is for nonperishable products. Since analyzing the convexity of the model is extremely complicated, a proposition is proved to define a... 

    On graphs whose star sets are (co-)cliques

    , Article Linear Algebra and Its Applications ; Volume 430, Issue 1 , 2009 , Pages 504-510 ; 00243795 (ISSN) Akbari, S ; Ghorbani, E ; Mahmoodi, A ; Sharif University of Technology
    2009
    Abstract
    In this paper we study graphs all of whose star sets induce cliques or co-cliques. We show that the star sets of every tree for each eigenvalue are independent sets. Among other results it is shown that each star set of a connected graph G with three distinct eigenvalues induces a clique if and only if G = K1, 2 or K2, ..., 2. It is also proved that stars are the only graphs with three distinct eigenvalues having a star partition with independent star sets. © 2008 Elsevier Inc. All rights reserved  

    A two-echelon inventory model with perishable items and lost sales

    , Article Scientia Iranica ; Volume 23, Issue 5 , 2016 , Pages 2277-2286 ; 10263098 (ISSN) Mahmoodi, A ; Haji, A ; Haji, R ; Sharif University of Technology
    Sharif University of Technology  2016
    Abstract
    This article deals with a single perishable item, continuous-review, two-echelon serial inventory system consisting of a warehouse and a retailer. Customer demands at the retailer are assumed to be Poisson. All items have a fixed shelf life and start aging on their arrival at the retailer. The demand that cannot be met immediately at the retailer is lost. All transportation times are fixed. If there is any stock in the warehouse, the lead time for the retailer would be the transportation time from the warehouse. Otherwise, the retailer orders are met with a delay. In this article, using an approximate technique, we first present a heuristic for finding cost-effective base stock policy and... 

    Synthesis of Amines, Quinoxalines and New 1,4-Dihydropyridines in Water, Reactions of Indoles and Oxidation of 1,4-Dihydropyridines Using Sodium Nitrite

    , Ph.D. Dissertation Sharif University of Technology Ghafuri, Hossein (Author) ; Mahmoodi Hashemi, Mohammad (Supervisor)
    Abstract
    Briefly in this thesis, these subjects have been investigated: In recent years, water is used as a solvent instead of an organic solvents have become more and more important due to cheap and environmental consideration. In this context, preparation of quinoxaline, pyrrole, new 1,4-dihydropyridine and reduction of imine to amine with 1,4-dihydropyridine derivatives as the reducing agents with the use of one-pot multicomponent reaction have been reported. The existence of several hydrogen bonding groups (NH) in the new dihydropyridines they acts as biologically active compounds in the forthcoming years. In continuation, oxidation of thiols to disulfides in the presence of NBS and NCS and...