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    Preparation and Modification of Lithium-ion Battery Membrane/Separator

    , M.Sc. Thesis Sharif University of Technology Javadi, Omid (Author) ; Soltanieh, Mohammad (Supervisor) ; Mousavi, Abbas (Supervisor) ; Fathollahi, Abolfazl (Co-Supervisor)
    Abstract
    Electrolyte separator is the major component of lithium-ion batteries which the battery safety directly depends on it. In this work, a membrane separator based on the polyvinylidene fluoride (PVdF) was prepared via non-solvent induced phase separation (NIPS) method with water and ethanol as non-solvent and a mixture of dimethylformamide (DMF) and acetone as solvents. The effect of various acetone/DMF ratios and type of non-solvent on the structural, mechanical and electrochemical properties of separator was studied. The separator was characterized by FE-SEM, tensile strength, electrochemical AC-impedance spectroscopy, thermal stability and linear sweep voltammetry (LSV). Additionally, the... 

    Preventing the transmission of harmful cognitive radio users in the presence of primary users

    , Article Proceedings - 2009 1st UK-India International Workshop on Cognitive Wireless Systems, UKIWCWS 2009, 11 December 2009 through 12 December 2009, New Delhi ; 2009 ; 9781457701832 (ISBN) Fathollahi, M ; Soleimanipour, M ; Sharif University of Technology
    2009
    Abstract
    A cognitive radio provides access to a licensed spectrum for unlicensed users opportunistically provided that they are not harmful for licensed users (primary users). We call a cognitive radio user (CR user) harmful, when it generates interference for primary users (PU) or occupies spectrum holes excessively. This paper discusses the spectrum management policy against harmful CR users. For this, we design a jammer signal which ruins transmission of harmful CR users and forces them to leave the spectrum without damaging the communication of PUs. This signal is designed using group subspace technique for both synchronous and asynchronous channels. Our simulation results show that the designed... 

    Optimization of a serpentine model for low-dispersion flows in micro channel turns

    , Article 5th International Conference on Perspective Technologies and Methods in MEMS Design, MEMSTECH 2009, Lviv-Polyana, 22 April 2009 through 24 April 2009 ; 2009 , Pages 136-140 ; 9789662191066 (ISBN) Fathollahi, E ; Afsharikia, S ; Taghizadeh Manzari, M.T ; Sharif University of Technology
    2009
    Abstract
    Chip-based micro fluidic separation systems often use serpentine channels to attain long separation lengths in a compact area. Such designs suffer from the dispersion, mostly 'racetrack' effect, due to the bends in the micro channels. The main goal of this paper is obtaining a model which has minimal racetrack in a serpentine geometry. A numerical analysis leads us to an optimized model which is different from previous attempts in this field. Our model uses modified turn radii, optimal length between bends with a constant zeta-potential boundary condition and a constant width through micro channel turns. It is shown that traveling fluid in this geometry has minimal dispersion as well as... 

    A Dynamic Scheduling Model with Multiple Process Planning Scenarios Using Markov Models

    , M.Sc. Thesis Sharif University of Technology Fathollahi Chimeh, Mahsa (Author) ; Haji, Babak (Supervisor)
    Abstract
    Cloud Manufacturing have been provided the proper context for efficient and effective using from distributed and various sources for agile and fast responsiveness to various customer demands. Product request from customers lead to define the operations in shop-floor levels that must be process by production equipment in shop-floors. The planning and scheduling problem of this activities have been most important challenge for decision makers. Therefore, the development of ways and methods can exploit efficiently from distributed resources and in confront of customer reqirement have been adaptive is most important. In this study an adaptive approach can be considered in terms of assigning the... 

    Design and Implement of Very Low Frequency AC Voltage Source

    , M.Sc. Thesis Sharif University of Technology Fathollahi, Mohammad Mahdi (Author) ; Kaboli, Shahriar (Supervisor)
    Abstract
    With the expansion of the use of electric energy, the importance of sustainable supply of this energy has been revealed. The task of supplying this energy is with power systems, therefore, for a stable supply of electrical energy, it is necessary to continuously monitor the systems. Power systems are composed of various destructible components such as cables. There are various methods and tests for maintaining and monitoring power cables. One of the daily maintenance methods of alternating current cables is called very low frequency testing. The main advantage of this test is the small and portable nature of the test equipment. In this thesis, the design of a very low frequency alternating... 

    A novel viewpoint to the green city concept based on vegetation area changes and contributions to healthy days: a case study of Mashhad, Iran

    , Article Environmental Science and Pollution Research ; 2021 ; 09441344 (ISSN) Nejatian, A ; Makian, M ; Gheibi, M ; Fathollahi Fard, A. M ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Abstract
    One of the significant challenges in urbanization is the air pollution. This highlights the need of the green city concept with reconsideration of houses, factories, and traffic in a green viewpoint. The literature review confirms that this reconsideration for green space has a positive effect on the air quality of large cities and to reduce the air pollution. The purpose of this study is to evaluate the annual vegetation changes in the green space of Mashhad, Iran as a very populated city in the middle east to study the air pollution. To investigate the relationship between the air pollution and vegetation, the Landsat 8 satellite images for summer seasons of 2013–2019 were used to extract... 

    A novel viewpoint to the green city concept based on vegetation area changes and contributions to healthy days: a case study of Mashhad, Iran

    , Article Environmental Science and Pollution Research ; Volume 29, Issue 1 , 2022 , Pages 702-710 ; 09441344 (ISSN) Nejatian, A ; Makian, M ; Gheibi, M ; Fathollahi Fard, A. M ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2022
    Abstract
    One of the significant challenges in urbanization is the air pollution. This highlights the need of the green city concept with reconsideration of houses, factories, and traffic in a green viewpoint. The literature review confirms that this reconsideration for green space has a positive effect on the air quality of large cities and to reduce the air pollution. The purpose of this study is to evaluate the annual vegetation changes in the green space of Mashhad, Iran as a very populated city in the middle east to study the air pollution. To investigate the relationship between the air pollution and vegetation, the Landsat 8 satellite images for summer seasons of 2013–2019 were used to extract... 

    Numerical Study of Geotextile Application in Downstream Filter Zone of an Embankment Dam with Clay Core

    , M.Sc. Thesis Sharif University of Technology Maghsoodian, Maedeh (Author) ; Shamsaie, Abolfazl (Supervisor)
    Abstract
    Nowadays, applications of the synthetic materials are developing in civil engineering projects and widely used in these projects. Therefore, during previous years; use of the Geotextiles as one of the Geosynthetic materials in order to filtration, drainage, separation, soil protection, etc have developed ever-increasing. The goal of this research is modeling and studies of the Geotextiles application in the downstream filter zone of embankment dams in combination with granular materials using FLAC2D software. Gordeh Bin embankment dam situated in West Azerbaijan province has been chosen as case study. In this matter, different models have been made with changes in thickness of the inclined... 

    groundwater level fluctuations forecasting using conjunction models of Wavelet - Neural-Fuzzy Network (WNF) and Wavelet-Neural Network (WNN) and linear model of ARIMA (case study: Qom plain

    , M.Sc. Thesis Sharif University of Technology Fathi, Bahman (Author) ; Shamsaei, Abolfazl (Supervisor)
    Abstract
    Prediction of groundwater level fluctuations is absolutely necessary for the proper manag ement of these precious resources. There are different methods to predict hydrological time series such as groundwater level. Linear models inefficiency in predicting nonlinear and n on-stationary time series cause researchers widely use artificial intelligence techniques such as Artificial Neural Networks (ANN), Fuzzy Inference System (FIS), Genetic Algorithm (GA) and their hybrid models such as Artificial Neural – Fuzzy Inference System (ANFIS). These smart models are capable to simulate nonlinear and non-stationary time series in suitable accu-racy using by a few time and data. By emersion of Wavelet... 

    , M.Sc. Thesis Sharif University of Technology Nazari, Fatemeh (Author) ; Shamsaei, Abolfazl (Supervisor)
    Abstract
    Entrance of air to close water conduits occurs in many ways. This phenomenon makes displeasing effects on water transport structures. Two-phase flows in closed conduits are studied experimentally, numerically and theoretically. Even after decades, due to the complexity of the subject, these studies still require development and reformation. Numerical and theoretical two-phase models are often limited to a special regime of flow."Volume Of Fluid"(VOF) is a model for non-mixing two-phase flows. "Fluent" software uses this model in this field of flows. Volume of fluid is used successfully in some problems like dam break or rising bubbles. Main disadvantage of this model is distribution of the... 

    Assessment of waterlogging and provide risk maps by using RS, GIS and field data (case study: Qazvin plain)

    , M.Sc. Thesis Sharif University of Technology Mansourian, Hamid (Author) ; Shamsaei, Abolfazl (Supervisor)
    Abstract
    Groundwater quality protection has a significant importance due to abundant applications of these resources in various fields such as agriculture, industry and drinking water. Removal of groundwater pollution is a time and money consuming process and often pollution is detected when improving the quality of groundwater is nearly impossible. For this vulnerability assessment there are three methods: Processing, Overlap-Index and Statistical Methods. Overlap-Index is composed of variety of maps such as Geology, Soil, Groundwater Depth and etc which uses in determining of vulnerability Index. In the present study for underground pollution potential determining, four indexes such as AVI، GOD،... 

    Efficient Management of River Water Quality Based on Pollution Trading Approach

    , Ph.D. Dissertation Sharif University of Technology Sarang , Amin (Author) ; Shamsai, Abolfazl (Supervisor)
    Abstract
    “Sustainable development” is a frequently used phrase, but the idiom has been experienced little since it was coined by the Brundtland, due to its intrinsic complications. The issue is going to compromise two key components; economy and ecology. One of the solutions based on concept of sustainable development that has been proposed for maintaining water quality at acceptable levels is to cap pollutant emissions at a sustainable level, then establish an economic market in which the right to discharge pollutants is traded according to market supply and demand mechanisms. Water quality trading or pollution trading is one such kind of market-based program that has also been described using names... 

    Semi-supervised Breast Cancer Subtype Clustering Using Microarray Datasets

    , M.Sc. Thesis Sharif University of Technology Vasei, Hamed (Author) ; Motahhari, Abolfazl (Supervisor)
    Abstract
    Gene expression microarrays can be used for precision medicine and targeted therapies. The data generated by microarrays are high-dimensional causing statistical inference of any parameter a daunting task. In this thesis, it is shown that regardless of high-dimensional datasets produced by microarrays, the inference can be robust in the sense that random selection of features results in the same conclusion as far as the number of selected features are chosen appropriately. Stratifying patients with breast cancer based on their gene expression levels shows that patient subtypes are almost independent of the feature selection strategy. Moreover, using less noisy datasets coming from RNAseq... 

    A Simulation for Better Understanding of Integrin Clustering and Activation

    , M.Sc. Thesis Sharif University of Technology Shams, Shahab (Author) ; Motahhari, Abolfazl (Supervisor)
    Abstract
    Today, computer simulations are employed prevalently by researchers to understand biological processes. The tendency to use computational methods has been increased recently due to the high costs and errors of experimental methods. Integrins are membrane proteins that mechanically attach cells to the extra cellular matrix (ECM) and derive some behaviors such as cell migration. Moreover, integrins have biochemical functions. They transduce environment signals and trigger chemical pathways. As a result, integrins regulate cell shape, motility, etc. The investigation of integrin behavior in a real environment is very difficult due to the presence of many other proteins that interfere with the... 

    Hydro-economical Method for the Optimal Capacity Design of Small Hydropower Plant (Case Study: Kohneh Lahijan Hydropower Plant)

    , M.Sc. Thesis Sharif University of Technology Mehrvand, Shahryar (Author) ; Shamsai, Abolfazl (Supervisor)
    Abstract
    In this thesis, we determine the optimal capacity of the power plants considering site specifications and Flow Duration Curve and evaluating economic parameters. Finally a design with more sufficient economical and hydrualical performance would be selected. The optimization algorithm used in this thesis is called "Charged System search" that is one of the newest meta-heuristic algorithms. This algorithm is inspired by the coulomb and gauss's laws of electrostatics in physics and utilizes a number of charged particles which influence each other based on their fitness values and their separation distances considering the governing law of coulomb.The proposed method in this thesis can be... 

    GIS Based Procedure to Determine Location of Cascade Small Hydropower Plants Case Study, Nokhan Area

    , M.Sc. Thesis Sharif University of Technology Serpoush, Behrad (Author) ; Shamsai, Abolfazl (Supervisor)
    Abstract
    Coinciding with the worldwide environmental issues and increasing demand for clean energy sources, hydropower plants have highly attracted decision- makers attention. Low manufacturing costs and pollutions which are made by these plants in comparison with another types of powerhouses, could be reason of that. And so on, hydropower locating and evaluating studies have been highly increased recently, specifically in developing countries. From the point of operation procedure, hydropower plants are generally divided in two types, run-of-he-river and storage projects. This study has concentrated on run-of-he-river projects and due to spotting plant location, Sefidbarg river basin... 

    Investigation of bed Stability in Downstream for the Diversion dam under Scour (Mill & Moghan case study)

    , M.Sc. Thesis Sharif University of Technology Gorji, Faeze (Author) ; Shamsai, Abolfazl (Supervisor)
    Abstract
    Numerical simulations and large eddy simulations (LES) of turbulent flow downstream of diversion dam , pool-riffle bedform in different geometrical ratios (different lengths of riffle and pool) with flow Reynolds number of 3.0 E+04 to 3.3E+04, downstream of special case study "Mill and Moghan diversion dam" with Froude number of 0.5 are presented The calculations are performed using a computational fluid dynamics model, FLOW-3D, which solves the Navier-Stokes equations in three dimensions with finite volume method. Numerical simulations are validated by comparing the numerical results of time-averaged flow patterns downstream of pool-riffle sequence with that of the experimental... 

    Assessment of Optimum Environmental Flows Using Economic Evaluation Methods

    , M.Sc. Thesis Sharif University of Technology Mazdarani, Sohrab (Author) ; Shamsai, Abolfazl (Supervisor)
    Abstract
    One of the main challenges of Water Resources Planning and Management (WRPM) is to balance water allocation between different uses. Usually, due to political and economic power of other uses, ecosystem receives less attention. Environmental flow is the allocated flow to ecosystem. Ecosystem provides a wide range of services to humanity. Therefore, environmental flow is not exclusively a matter of sustaining ecosystem but also a matter of providing humans with better life. Several methods have been developed to determine the environmental flow but only a few consider its socio-economic aspects. Consideration of these aspects could assist decision-makers with determining the optimum flow and... 

    Application of Gis & Fuzzy Technique for Order-Preference by Similarity to Ideal Solution (Topsis) in Siting Water Reservoires

    , M.Sc. Thesis Sharif University of Technology Jozaghi, ali (Author) ; Shamsai, Abolfazl (Supervisor)
    Abstract
    Sustainable agricultural development in the country without regard to water supply problems in terms of time and place is not possible. Construction of water storage tanks filled with water and seasonal use in dry seasons in the effective action in the optimal use of water in the climate of (low and irregular rainfall) is. The most important step in the construction of water storage tanks to choose the best point for the construction of the reservoir basin in order to reduce costs and increase efficiency. Chndmyarh different methods to decide the best option for finding a few options from there. Among these methods can be Tapsys two methods (TOPSIS) and hierarchical analysis (AHP) pointed... 

    Analysis of Genes Regulating Beta Cells Cell Cycle

    , M.Sc. Thesis Sharif University of Technology Saraei, Tannaz (Author) ; Motahari, Abolfazl (Supervisor)
    Abstract
    Diabetes mellitus is a group of disorders where the level of blood sugar remains high for a long period of time. This increase may be due to either reduced insulin secretion from the pancreatic gland, or insulin resistance, or both. Another key reason is the destruction of beta cells due to functional defect in the body’s immune system. Current treatments include controlling diet, insulin injection and pancreatic transplantation, all of which are temporary. For this reason, finding genetic factors participating in the progression of the disease and adapting treatments to these factors are under intensive studies.In this thesis, available information resources including genomic, biological...