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    Resource Management in Space-Division Multiplexed Elastic Optical Networks

    , M.Sc. Thesis Sharif University of Technology Nikkhah, Ali (Author) ; Pakravan, Mohammad Reza (Supervisor)
    In recent years, Internet traffic has nearly doubled in the core network every two years, and it is expected to continue to grow in the future. With this growth, there is a need for very high capacity and economically efficient transmission systems, which optical communication is the best choice. Elastic optical network (EON) is one of the best options for achieving this goal in the future. Unlike existing networks, the transmission parameters of EON will be customizable, which will have an essential role in optimizing bandwidth assignment. The problem facing scientists today is to approach the final physical capacity of current optical fibers. The solution proposed for this challenge is... 

    Development of Computational Fluid Dynamics Model for Spatial Distribution of Greenhouse Temperature and Humidity Considering Plant Evapotranspiration

    , M.Sc. Thesis Sharif University of Technology Nikkhah, Amir Farzin (Author) ; Roshandel, Ramin (Supervisor)
    The purpose of this study is to develop a simulated model of a greenhouse using two different ventilation systems, a fan&pad system and an air-soil converter equipped with a sprinkler in order to compare the cooling performance of these two systems in hot seasons. The main focus of the analysis of the results is on how the temperature and humidity are distributed throughout the greenhouse space. In order to develop a three-dimensional model with computational fluid dynamics method, greenhouse simulation in Ansis software has been used. The development of ventilation model in the greenhouse is done by creating boundary conditions using optimal design. Also, to simulate soil-air conditioning... 

    Investigation of in situ prepared polypropylene/clay nanocomposites properties and comparing to melt blending method

    , Article Materials and Design ; Volume 31, Issue 1 , 2010 , Pages 76-84 ; 02641275 (ISSN) Baniasadi, H ; Ramazani S. A. A ; Javan Nikkhah, S ; Sharif University of Technology
    The morphological, physical and mechanical properties of polypropylene/clay nanocomposites (PPCNs) were prepared by in situ polymerization are investigated. Non-modified scmectite type clay (e.g. bentonite) was used to prepare bi-supported Ziegler-Natta catalyst of TiCl4/Mg(OEt)2/clay. Exfoliated PPCNs were obtained by in situ intercalative polymerization of propylene using produced bi-supported catalyst. X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) micrograph were used to assess the clay morphology and dispersion of clay. The crystalline structures of PPCNs were characterized by differential scanning calorimetry (DSC). The mechanical properties of PPCNs were... 

    Investigation of Production Increasing in In-situ Preparation of Polyolefin/clay Nanocomposites

    , M.Sc. Thesis Sharif University of Technology Javan Nikkhah, Sousa (Author) ; Ramazani Saadat Abadi, Ahmad (Supervisor)
    This project is devoted to experimental investigation of increasing on production of polyethylene/clay nanocomposites (PECNs) and polypropylene/clay nanocomposites (PPCNs) via in-situ polymerization method. First of all we produced bi-supported Ziegler-Natta catalyst to polymerized polyolefins nanocomposites. Bentonite type clay and Magnesiumethoxide (Mg (OEt)2) were used as the support of Tetrachloridetitanium (TiCl4). Catalyst support and polymerization process have been done in slurry phase using Triisobutylaluminum (TiBA) as the co-catalyst. The efficiency of preapared bi-supported Ziegler-Natta was reasonably high (average 200 (gr. Product/mmol Ti. h) for PECNs and 195 (gr. Product/mmol... 

    The Design and Construction of a Marine Current Turbine and Modeling the Flow Around It

    , M.Sc. Thesis Sharif University of Technology Nikkhah, Ehsan (Author) ; Seif, Mohammad Saeed (Supervisor) ; Abbaspour, Madjid (Supervisor)
    Nowadays, science and technology, once again, lead approach to renewable natural resources to access energy due to fossil resources restrictions. Growing need for energy, being concerned about exhaustion of fossil resources, environmental pollution caused by burning fossil materials, climate warming and the greenhouse effect and etc. are obvious evidences of aforesaid fact. On the other hand, oceans and seas are large reservoirs of energy which comes from sunlight, geothermal resources, Earth's rotation and gravity by means of mechanical and hydrothermal processes. During the years, many ideas were conducted to achieve and mine the mentioned enormous energy potential of the oceans and seas.... 

    Investigation of properties of polyethylene/clay nanocomposites prepared by new in situ ziegler-natta catalyst

    , Article Materials and Design ; Volume 30, Issue 7 , 2009 , Pages 2309-2315 ; 02641275 (ISSN) Nikkhah, S. J ; Ramazani Saadat Abadi, A ; Baniasadi, H ; Tavakolzadeh, F ; Sharif University of Technology
    This paper is devoted to investigation of morphological and physical-mechanical properties of polyethylene (PE)/clay nanocomposites prepared via in situ polymerization method using bi-supported Ziegler-Natta catalyst. Bentonite type clay and MgCl2 (ethoxide type) were used as the support of TiCl4. Catalyst support and polymerization process have been done in slurry phase using Triisobutylaluminum as the co-catalyst. The microstructure of the nanocomposites was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM indicated that almost fully exfoliated PE/clay nanocomposites were produced successfully using this method. According to permeability... 

    A selective chemiresistive sensor for the cancer-related volatile organic compound hexanal by using molecularly imprinted polymers and multiwalled carbon nanotubes

    , Article Microchimica Acta ; Volume 186, Issue 3 , 2019 ; 00263672 (ISSN) Janfaza, S ; Banan Nojavani, M ; Nikkhah, M ; Alizadeh, T ; Esfandiar, A ; Ganjali, M. R ; Sharif University of Technology
    Springer-Verlag Wien  2019
    A chemiresistive sensor is described for the lung cancer biomarker hexanal. A composite consisting of molecularly imprinted polymer nanoparticles and multiwalled carbon nanotubes was used in the sensor that is typically operated at a voltage of 4 V and is capable of selectively sensing gaseous hexanal at room temperature. It works in the 10 to 200 ppm concentration range and has a 10 ppm detection limit (at S/N = 3). The sensor signal recovers to a value close to its starting value without the need for heating even after exposure to relatively high levels of hexanal  

    Distributed Generation Planning in Deregulated Electric Industry Using Multi-objective Optimization

    , M.Sc. Thesis Sharif University of Technology Ahmadi, Mohammad (Author) ; Ehsan, Mehdi (Supervisor)

    Methods of Clearing Reactive Power Market and Cost Allocation in Pool Structure

    , M.Sc. Thesis Sharif University of Technology Kharraty, Saeed (Author) ; Ehsan, Mehdi (Supervisor)
    Restructuring and privatization in power system such as any industry leads to better market operation and more social welfare. Since two decade the power system in many countries have changed from monopoly to free market. In a restructured network the technical and economical aspects should be considered together. Ancillary services are needed for any power system to be operated in an optimal and secure manner. Reactive power and voltage regulation is one of the most important ancillary services in the network. this service should be supplied by its providers through a competitive market and system operator determines the optimal dispatch among different bids. The cost of purchasing reactive... 

    Dynamic Security Assessment in Restructured Power Systems

    , Ph.D. Dissertation Sharif University of Technology Kheradmandi, Morteza (Author) ; Ehsan, Mahdi (Supervisor)
    This thesis addresses the problem of dynamic security assessment in power sys-tems with an emphasis on its application in restructured power systems and issues arising in its applications. The new electric utility environment has an immedi-ate consequence of emphasis on reliability and secure operation of power systems. This requires faster and more precise methods to assess the dynamic aspect of se-curity. On the other hand, this issue is becoming challenging when the determined dispatch might not be accommodated due to violation of the limits.This thesis addresses the problem of dynamic security assessment in power sys-tems with an emphasis on its application in restructured power systems... 

    Optimal Sizing and Operation of CHP Based on Stochastic Programming

    , M.Sc. Thesis Sharif University of Technology Bozorg, Mokhtar (Author) ; Ehsan, Mehdi (Supervisor)
    CHP (Combined Heat and Power) generates electricity and thermal energy simultaneously from input fuel. Since it has high energy efficiency and low installation time, it is an appropriate approach in energy management of residential complexes. In this project, stochastic programming based on Monte Carlo approach is used to handle uncertainties in the optimal sizing of CHP for residential complexes. Availability of CHP, boiler and AC bus as well as the electrical and thermal load forecast errors are considered as stochastic variables. Minimizing system total cost considering the probability of each scenario obtained from the scenario reduction algorithm is the objective function. The system... 

    Multi Objective Distributed Generation Planning in a Flexible Environment

    , Ph.D. Dissertation Sharif University of Technology Soroudi, Alireza (Author) ; Ehsan, Mehdi (Supervisor)
    The process of deregulation that has involved electricity many markets has introduced several new interesting research topics in power system area. This thesis addresses one of the most fascinating issues among them: the study of distributed generation both renewable and conventional integration in distribution networks. From the distribution network operator (DNO)'s point of view, it is of interest to develop a comprehensive methodology which considers various distributed generation technologies as an option for supplying the demand in distribution networks. In this thesis, the planning problem has been multi-objectively modeled. This will help the planner in decision making while knowing... 

    Genco's Bidding Strategy in Day-Ahead Energy Market Considering Demand Response

    , M.Sc. Thesis Sharif University of Technology Kazemi, Mostafa (Author) ; Ehsan, Mehdi (Supervisor)
    Since 1980s the electricity market has been gradually evolving from a monopoly market into a liberalized one for encouraging competition and improving efficiency. This brings the opportunity for generation companies (Gencos) to make more profits while embracing more risks of not being dispatched. Therefore, it has become a core interest for the Gencos to develop optimal bidding strategies to maximize the profits and minimize the risks while participating in such a competitive market. Error of determining day-ahead electricity price is one of the sources of the risk. Energy price has a high impact on bidding strategy optimization process. So it should be determined with low error which is not... 

    , M.Sc. Thesis Sharif University of Technology Mahmoodzadeh, Zahra (Author) ; Ehsan, Mehdi (Supervisor)
    Losses are unavoidable in any parts of power systems, from generation to receiving nodes and occur in transmission and distribution networks. However, the main loss component is produced in distribution networks. Energy losses in distribution networks are about 70% of technological transport energy losses.
    Energy losses in distribution networks are an important indicator for the planning and operation of the system. A fast, reliable and accurate energy loss calculation method is required for optimal operation of the distribution networks.
    Energy loss depends on network's operating conditions. Loads values and loads factors are time variables; therefore, methods based on probability... 

    Security Constrained Unit Commitment With Natural Gas Transmission Delivery Constraints

    , M.Sc. Thesis Sharif University of Technology Badakhshan, Sobhan (Author) ; Ehsan, Mahdi (Supervisor)
    Natural gas power plant installed in power system as rapid start unit. In the recent decades, with increasing in the number of gas generating units in the world, consideration of natural gas transmission network in optimal solution of security-constrained unit commitment (SCUC) become a non-negligible problem. The gas transmission grid constraints integrated into the scheduling of thermal units in the proposed model for minimizes power system operating cost. In a power plant transmission of natural gas to power plant is very important because congestion in natural gas pipeline increases. This model could consider natural gas storage tank in gas transmission network as decision variable.... 

    Planning of Energy Storage Systems with the Main Goal of Managing the Output Power of Wind Farms

    , M.Sc. Thesis Sharif University of Technology Saber, Hossein (Author) ; Ehsan , Mehdi (Supervisor)
    Uncertain fuel prices and also global climate changes are accompanied by some state initiatives such as renewable portfolio standards (RPS). This has caused a fast growth in the amount of renewable energy installed worldwide especially wind energy over last decades. However, the intrinsic characteristics of wind farms output power, i.e. intermittency and volatility of wind speed along with being non-dispatchable in output generation of wind turbine raises many new technical and financial challenges for power system operators and planners. Up to these issues, large level of wind power penetration causes a growing concern in wind energy curtailment issue which the wind farm’s operator may be... 

    Retailer’s Medium-term Planning in Distribution Network Considering Uncertainty and Competitive Enviroment

    , Ph.D. Dissertation Sharif University of Technology Kharrati, Saeed (Author) ; Ehsan , Mehdi (Supervisor)
    Electricity retailers are one of the power market entities which act as an intermediary between the producers in the wholesale market and the consumers in the retail side. The main task of a retailer in the power market is to set contract with the consumers to supply their electricity during a pre-specified time period and to participate in the wholesale market to supply the electricity needed by its costomers. Retailer’s contract with its customers may be a simple contract with a fixed pre-determined energy price or include some more complicated feathures such as involvement of a percent of green energy or variable price and demand response contracts. Moreover, retailer can supply its... 

    Scheduling of Retailers Performance in Electrical Energy Markets with Energy Production;Sell in Pool Market; and Demand Response Policies

    , M.Sc. Thesis Sharif University of Technology Gilasi, Yasin (Author) ; Ehsan, Mehdy (Supervisor)
    Recent years of capitalism bold role and the competitive environment of variant fields of our life, sparking the idea which considers the electricity (one of the most crucial human requirement) as a commodity of a competitive market to be traded between confident subscribers by easy access. Therefore, by converting the exclusive structure of electricity supply system to a competitive one, some new roles are created to fulfill the electricity generation, transmission and distribution processes. Retail is one of the new roles, defined as a power system restructuring development helper by support of electricity trading, which can be involved in different transactions according to the market... 

    Linked Planning of Power Grids and Subsidy Policies on Using Photovoltaic Cells for Residential Electricity Supply

    , M.Sc. Thesis Sharif University of Technology Balmaki, Saeed (Author) ; Ehsan, Mehdi (Supervisor)
    In recent years, due to restructuring in the electric power industry, distributed generation has become one of the most important subjects and DGs and renewable energy sources have been increasingly expected as a supplement and an alternative to a conventional large scale central power system. their success depends not only on the distribution of the available renewable energy sources in a region but also on the power grids connectable capacity in the area. Photovoltaic system is one of the best RESs for residential electricity supply because it is noiseless and solar power is widely available and households can use it via photovoltaic cells in their homes. There are two major problems... 

    Bidding and Offering Strategy of Hybrid Electric Companies in Day-ahead Energy Market

    , Ph.D. Dissertation Sharif University of Technology Kazemi, Mostafa (Author) ; Ehsan, Mehdi (Supervisor)
    This Thesis presents a new approach for determining the day-ahead bidding strategies of a hybrid electric energy company. The company has both energy generation and energy retailing businesses in a competitive electricity market. Demand response programs are also considered in the retail side of the company in order to hedge the risk of participation in wholesale market. Price-taker and price maker companies are considered in this thesis separateky.For the price-taker hybrid structure, the predivtion of day-ahead prices are used to evaluate the optimum bidding and offering strategies. Also, day-ahead market price uncertainty is modeled, using non-probabilistic Information Gap Decision Theory...