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    Sustainable-Resilient Supplier Selection Through Fuzzy Multi-Criteria Decision Making Approaches

    , M.Sc. Thesis Sharif University of Technology Varchandi, Sahar (Author) ; Akbari Jokar, Mohammad Resa (Supervisor) ; Memari, Ashkan (Co-Supervisor)
    Abstract
    Today, with the expansion of business relations at international levels, there are many organizations that operate in global supply chains. Activities at such levels face new types of challenges in various fields of "supply chain management" pillars, of which "supplier selection" is one of them. The possibility of unexpected events, the need to comply with environmental protection laws, as well as the need to take into account social considerations, are among the things that have increased by being in larger supply chains, making it challenging to provide the basic resources needed in such chains and forcing their managers to considering considerations other than what they have always... 

    Jahn-Teller Effect in Diamond Vacancy Under Stress

    , M.Sc. Thesis Sharif University of Technology monfared, Mohammad (Author) ; Vesaghi, M. A (Supervisor) ; Babamoradi, M (Co-Advisor)
    Abstract
    Electron states of diamond vacancy under stress were studied theoretically. The generalized Hubbard model is used to calculate the electrons energy levels. The results shows that the degeneracy of some levels (T, with triple space degeneracy) reduced to levels with lower degeneracy (E, with double space degeneracy and A, without degeneracy). Besides this spiting of degeneracy the energy of all states changed and therefore the transition energy between these states changed too. Jahn-Teller effect was observed  

    Adaptive Teaching of the Iranian Sign Language Based on Continual Learning Algorithms

    , M.Sc. Thesis Sharif University of Technology Memari, Morteza (Author) ; Taheri, Alireza (Supervisor)
    Abstract
    In addition to being their primary means of communication with the people around them, sign language for deaf children plays a significant role in shaping their intellectual and cognitive development. Research has shown that the use of robots in education has a substantial impact on the learning process of the learner. As the teaching process requires long-term interaction with different users, the use of adaptable techniques enables the creation of a social robot capable of productive interaction with users of varying performance levels. One of the objectives of this research is to use continual learning algorithms to enhance adaptability in the teaching process. Another goal is to design... 

    Experimental and Numerical Investigation on the Single Drop Liquid-liquid Mass Transfer in the Presence of Magnetic Nano-particles (Ferrofluids) and Magnetic Field

    , Ph.D. Dissertation Sharif University of Technology Memari, Mohammad (Author) ; Molaie Dehkordi, Asghar (Supervisor) ; Seif Kordi, Ali Akbar (Co-Supervisor)
    Abstract
    The main objective of the present work was to improve the turbulence in single drops using ferrofluids (magnetic nanoparticles) in the presence of uniform and oscillating magnetic fields. In this regard, magnetite nanoparticles ($\mathrm{Fe_3O_4}$) were synthesized by co-precipitation method, characterized using DLS, FT-IR, XRD, VSM, and TEM, and their stability was checked by UV-Vis. The obtained results indicate the proper synthesis of nanoparticles with a mean diameter of about 20 nm and by coating their surfaces by silane that were well stabilized in the base fluid. In the numerical section, the governing equations of transport phenomena for a single drop containing magnetic fluids were... 

    Studying Instances of Conflict of Interest in Some Job Positions in Iran’s Ministry of Health, Treatment and Medical Education

    , M.Sc. Thesis Sharif University of Technology Memari Beyraq, Behzad (Author) ; Talebian, Masoud (Supervisor) ; Fatemi Ardestani, Farshad (Co-Supervisor)
    Abstract
    This study investigates and enumerates instances of conflict of interests in some job positions in Iran’s Ministry of Health, Treatment and Medical Education. To achieve this goal, we interviewed people involved in the health field and reviewed job descriptions as well. By adopting the prevalent definition of conflict of interests regarding the duties, authorities, and responsibilities, instances of conflict of interests has been relatively identified in each position. The results show that the main reasons (determinants) for cases of conflict of interests can fall into three categories. First, duties of positions are in such a way that being a shareholder, CEO, and member of the board of... 

    Real-Time Fusion of Asynchronous Data in Distributed Sensor Networks

    , Ph.D. Dissertation Sharif University of Technology Talebi, Hadi (Author) ; Hemmatyar, A. M. Afshin (Supervisor)
    Abstract
    Real-time asynchronous data fusion for high-speed phenomena is an important and challenging task in the sensor networks. Examples of data fusion applications in sensor networks are: managing the traffic of maneuvering airplanes and ground vehicles in airside areas of an airport, traffic management in streets and roads, Driver Assistance Systems, guidance of antiaircraft and antimissile missiles. In all the data fusion applications the estimation of the required variables is necessary.
    In this research two methods are introduced for real-time asynchronous data fusion, especially for track-to-track fusion of high-speed phenomena in sensor networks. The effectiveness and usability of these... 

    Trajectory Optimization of a Dual-arm Cam-lock Robot Considering Redundancy

    , M.Sc. Thesis Sharif University of Technology Rashidnejhad, Sajad (Author) ; Meghdari, A. (Ali) (Supervisor) ; Ghaemi Osgouie, Kambiz (Supervisor)
    Abstract
    In the present work, trajectory optimization of the Dual-Arm Cam-Lock robot considering kinematic and dynamic redundancy is performed. First, the optimal control problem is solved only considering kinematic redundancy and then is solved considering dynamic redundancy. General form of the dynamic model for the system is developed using Lagrangian relations. Global optimization method is used for redundancy resolution problem. A performance index is defined based on the consumed kinetic energy and is minimized through a desired trajectory using the global optimization method. Formulations of optimal control problem are derived and initial boundary problem is changed to two point boundary value... 

    Spectrophotometric Determination of Ametryn Herbicide in Drainage Water Based on Aggregation of Gold Nanoparticles Capped with Citrate

    , M.Sc. Thesis Sharif University of Technology Rastgar, Mortaza (Author) ; Hormozi-Nezhad, Mohammad Reza (Supervisor) ; Torkian, A (Supervisor)
    Abstract
    Due to vast use of Ametryn herbicide in agricultural and even non-agricultural activities and the possibility of contamination of carp and natural water sources by this herbicide, determination of this herbicide in surface and ground water sources is very important. Therefor introducing simple and sensitive method for determination of Ametryn is critical.
    This study demonstrate a simple and sensitive colorimetric method for the detection and determination of Ametryn based on aggregation of citrate capped AuNPs. Studied method relies upon shape and distance dependent AuNPs surface plasmon resonance. By replacing the sulfide containing Ametryn herbicide with citrate molecules on AuNPs... 

    Application of Multiscale methods for Modeling Spatial Heterogeneity in Complex Reservoirs

    , M.Sc. Thesis Sharif University of Technology Hajizadeh Mobaraki, Alireza (Author) ; Farhadpour, Farhad A (Supervisor) ; Sayf Kordi, Ali Akbar (Supervisor)
    Abstract
    Underground reservoirs are highly complicated due to the presence of spatial heterogeneities at length scales that span from micrometer in pore structure of the rocks to kilometer in the reservoir models. While large-scale flow units need to be characterized using seismic and well data, detailed displacements of fluids in pore space need to be modeled using thin section analysis and pore network modeling. It is therefore necessary to adopt a multi-scale approach to reservoir description to make best use of all the available data that vary over several orders of magnitude, from micro-scale in pore structure to field scale in reservoir flow models. In this thesis, an integrated framework for... 

    Uranium Recovery from Liquid Waste of UCF by Solvent Extraction Method

    , M.Sc. Thesis Sharif University of Technology Aminoro-a-yaei Yamini, Leyla (Author) ; Samadfam, Mohammad (Supervisor) ; Taghizadeh, Mohammad (Supervisor) ; Ghasemi, Mohamad Reza (Co-Advisor)
    Abstract
    The Atomic Energy Organization of Iran (AEOI) has launched a program of low level waste management. This program also includes waste produced at Uranium Conversion Facility (UCF) of Esfahan. The liquid waste, which was generated during the operation of plant and concentrated in lagoon, was characterized for the development of the treatment process. The aim of this study was to recovery of uranium content of liquid waste in the lagoon. The recovery of uranium has the advantage of saving this valuable metal and the avoidance of unacceptable discarding solution to the environment. Uranium may be recovered from an aqueous solution by precipitation, solvent extraction and ion exchange.... 

    Surface micromorphology and fractal geometry of Co/CP/X (X = Cu, Ti, SM and Ni) nanoflake electrocatalysts

    , Article RSC Advances ; Volume 6, Issue 32 , 2016 , Pages 27228-27234 ; 20462069 (ISSN) Ţəlu, Ş ; Solaymani, S ; Bramowicz, M ; Naseri, N ; Kulesza, S ; Ghaderi, A ; Sharif University of Technology
    Royal Society of Chemistry  2016
    Abstract
    This paper analyses the three-dimensional (3-D) surface texture of Co/CP/X (X = Cu, Ti, SM and Ni, CP: carbonaceous paste) nanoflakes prepared electrochemically using a conventional three electrode system. The surface chemical composition of the samples was investigated by X-ray photoelectron spectroscopy (XPS). Surface images were recorded using scanning electron microscopy (SEM) and analyzed by means of the fractal geometry. Statistical, fractal and functional surface properties of the prepared samples were computed. The statistical functions applied to the SEM data were employed in order to characterise the surfaces topographically (in amplitude, spatial distribution and pattern of... 

    Effects of two- and three-dimensional graphene-based nanomaterials on the fatigue behavior of epoxy nanocomposites

    , Article Materials Today Communications ; Volume 24 , September , 2020 kordi, A ; Adibnazari, S ; Imam, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Epoxy resins and their derivatives, such as composites and epoxy adhesives, are widely used in various industries. However, epoxy resins have low performance against dynamic loading and crack propagation. Graphene-based nanomaterials can improve the mechanical performance of polymeric composites because of their appropriate mechanical properties and high surface area. This study aimed to investigate the effect of Two-Dimensional Graphene Oxide (2DGO) and Three-Dimensional Nitrogen-Doped Graphene (3D(N)G) nanomaterials on the fatigue behavior of epoxy resin. 2DGO was produced by the modified Hummer's method and 3D(N)G was synthesised by hydrothermal process, followed by freeze-drying.... 

    Microstructure, fractography, and mechanical properties of hardox 500 steel tig-welded joints by using different filler weld wires

    , Article Materials ; Volume 15, Issue 22 , 2022 ; 19961944 (ISSN) Zuo, Z ; Haowei, M ; Yarigarravesh, M ; Assari, A. H ; Tayyebi, M ; Tayebi, M ; Hamawandi, B ; Sharif University of Technology
    MDPI  2022
    Abstract
    This paper deals with the effects of three low-carbon steel filler metals consisting of ferritic and austenitic phases on the weld joints of the tungsten inert gas (TIG) welding of Hardox 500 steel. The correlation between the microstructure and mechanical properties of the weld joints was investigated. For this purpose, macro and microstructure were examined, and then microhardness, tensile, impact, and fracture toughness tests were carried out to analyze the mechanical properties of joints. The results of optical microscopy (OM) images showed that the weld zones (WZ) of all three welds were composed of different ferritic morphologies, including allotriomorphic ferrite, Widmanstätten... 

    Site-specific protein conjugation onto fluorescent single-walled carbon nanotubes

    , Article Chemistry of Materials ; Volume 32, Issue 20 , 2020 , Pages 8798-8807 Zubkovs, V ; Wu, S. J ; Rahnamaee, S. Y ; Schuergers, N ; Boghossian, A. A ; Sharif University of Technology
    American Chemical Society  2020
    Abstract
    Semiconducting single-walled carbon nanotubes (SWCNTs) are among the few photostable optical emitters that are ideal for sensing, imaging, drug delivery, and monitoring of protein activity. These applications often require strategies for immobilizing proteins onto the nanotube while preserving the optical properties of the SWCNTs. Site-specific and oriented immobilization strategies, in particular, offer advantages for improving sensor and optical signaling responses. In this study, we demonstrate site-specific protein immobilization of a model of enhanced yellow fluorescent protein with a single engineered cysteine residue, using either single-stranded DNA or a pyrene-containing linker to... 

    Estimation of current-induced scour depth around pile groups using neural network and adaptive neuro-fuzzy inference system

    , Article Applied Soft Computing Journal ; Volume 9, Issue 2 , 2009 , Pages 746-755 ; 15684946 (ISSN) Zounemat Kermani, M ; Beheshti, A. A ; Ataie Ashtiani, B ; Sabbagh Yazdi, S. R ; Sharif University of Technology
    2009
    Abstract
    The process of local scour around bridge piers is fundamentally complex due to the three-dimensional flow patterns interacting with bed materials. For geotechnical and economical reasons, multiple pile bridge piers have become more and more popular in bridge design. Although many studies have been carried out to develop relationships for the maximum scour depth at pile groups under clear-water scour condition, existing methods do not always produce reasonable results for scour predictions. It is partly due to the complexity of the phenomenon involved and partly because of limitations of the traditional analytical tool of statistical regression. This paper addresses the latter part and... 

    Magnetic anisotropies in FeCo fine particles

    , Article Journal of Magnetism and Magnetic Materials ; Volume 300, Issue 2 , 2006 , Pages 525-531 ; 03048853 (ISSN) Zoriasatain, S ; Azarkharman, F ; Sebt, S. A ; Akhavan, M ; Sharif University of Technology
    2006
    Abstract
    The single-domain particles, especially FeCo fine particles have many applications in magnetic information technology. We have prepared Fe 1-xCox fine particles for different x by borohydride method and measured the magnetic and structural properties of the samples. We have then determined the variations of coercivity and anisotropy energy versus x in Fe1-xCox fine particles. The obtained results have been analyzed on the basis of various magnetic anisotropies. Magnetic anisotropies affect the coercivity of the medium for each x as follows: shape and crystal anisotropies for x=0, surface and crystal anisotropies for x=1, shape, induced and crystal anisotropies for x=0.3 and 0.5, and shape... 

    Magnetic viscosity-coercivity relation for Fe1-xCox fine particles

    , Article Physica B: Condensed Matter ; Volume 403, Issue 1 , 2008 , Pages 12-15 ; 09214526 (ISSN) Zoriasatain, S ; Sebt, S. A ; Akhavan, M ; Sharif University of Technology
    2008
    Abstract
    The variation of the applied field results in a subsequent change of magnetization with time. There is a relationship between the coercivity (Hc), as the equilibrium characteristic of the system, and its magnetic stability (1/S), as a parameter characterizing the time dependence. 1/S as a function of Hc has been measured and studied for different Fe1-xCox samples. We synthesized several samples with different values of x by applying various magnetic fields during the grains' growth, and observed a linear relationship between 1/S and Hc. © 2007 Elsevier B.V. All rights reserved  

    Time dependence of magnetization in Fe1-xCox fine particles

    , Article 4th International Conference on Magnetic and Superconducting Materials, MSM'05, Agadir, 5 September 2006 through 8 September 2006 ; Volume 3, Issue 9 , 2006 , Pages 3220-3224 ; 18626351 (ISSN) Zoriasatain, S ; Seht, S. A ; Akhavan, M ; Sharif University of Technology
    2006
    Abstract
    The change of the applied field in a medium containing anisotropic magnetic grains, makes the number of magnetic moments in the field direction, and in the opposite direction to vary. Near H = Hc, probability of transition between the two minimum energies (SW model) increases strongly and the magnetization of system varies rapidly. We measured the time dependence of magnetization for various Fe1-xCOx samples, in the presence of some step fields. These samples were grown via solving iron, and cobalt salts with borohydride and then, heat treatment was accomplished on them. The results of time measurement of magnetization in step fields reveals a linear proportionality between coercivity and... 

    Estimating the four parameters of the Burr III distribution using a hybrid method of variable neighborhood search and iterated local search algorithms

    , Article Applied Mathematics and Computation ; Volume 218, Issue 19 , 2012 , Pages 9664-9675 ; 00963003 (ISSN) Zoraghi, N ; Abbasi, B ; Niaki, S. T. A ; Abdi, M ; Sharif University of Technology
    2012
    Abstract
    The Burr III distribution properly approximates many familiar distributions such as Normal, Lognormal, Gamma, Weibull, and Exponential distributions. It plays an important role in reliability engineering, statistical quality control, and risk analysis models. The Burr III distribution has four parameters known as location, scale, and two shape parameters. The estimation process of these parameters is controversial. Although the maximum likelihood estimation (MLE) is understood as a straightforward method in parameters estimation, using MLE to estimate the Burr III parameters leads to maximize a complicated function with four unknown variables, where using a conventional optimization such as... 

    A hybrid project scheduling and material ordering problem: modeling and solution algorithms

    , Article Applied Soft Computing Journal ; Volume 58 , 2017 , Pages 700-713 ; 15684946 (ISSN) Zoraghi, N ; Shahsavar, A ; Niaki, S. T. A ; Sharif University of Technology
    2017
    Abstract
    A novel combination of a multimode project scheduling problem with material ordering, in which material procurements are exposed to the total quantity discount policy is investigated in this paper. The study aims at finding an optimal Pareto frontier for a triple objective model derived for the problem. While the first objective minimizes the makespan of the project, the second objective maximizes the robustness of the project schedule and finally the third objective minimizes the total costs pertaining to renewable and nonrenewable resources involved in a project. Four well-known multi-objective evolutionary algorithms including non-dominated sorting genetic algorithm II (NSGAII), strength...