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Optimal Distributed Generation Allocation Considering Power Qaulity Indices
, M.Sc. Thesis Sharif University of Technology ; Mokhtari, Hossein (Supervisor)
Abstract
The demand for independent power generation has been increased in recent years due to the growing demand in distributed networks, losses and power qaulity in power systems. These losses occur in transmission to distribution networks from the generation sites to the end-user loads which have harmonic losses besides fundamental losses.. The non-linear load makes the harmonics flow in the line and create the harmonic losses. However, in a distributed network with several DGs of different types and with all kinds of variable nature loads, an optimal power balance in the system has to be achieved. This optimal objective, which results in minimal energy losses over a specific period of time,...
Dynamic Simulation of Molten Carbonate Fuel Cell
, M.Sc. Thesis Sharif University of Technology ; Pishvaie, Mahmoud Reza (Supervisor)
Abstract
In this work, a model was presented for an MCFC fuel cell with internal reforming and combustion chamber. The model consists of mass and heat transfer equations beside the chemical and electrochemical reaction rate equations. Velocity distribution due to reactions and temperature distribution along the cell is considered. The model has been simulated in steady state form using finite difference method in MATLAB package environment accompanied by the analysis of the dynamic behavior of cell using method of lines in Simulink environment. Simulation results have been validated with experimental data extracted from literature. The last part of the work concerns with sensitivity analysis of some...
Polysaccharide-Based Nanocomposites as Green Sorbents in Microextraction Methodologies
, Ph.D. Dissertation Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
This thesis is focused on the preparation and use of polysaccharides as extractive phases in various extraction methods, such as the micro solid phase extraction (µ-SPE), needle trap microextraction (NTME) and thin film microextraction (TFME).In the first research, feasibility of the online µ-SPE method using cellulose acetate (CA) fibers was investigated. For this purpose, CA fibers were prepared by electrospinning technique and then placed into µ-SPE cartridge. With this method, it was possible to simultaneously extract the drug compounds in the urine and plasma samples. The enrichment factor and limits of detection (LODs) were obtained in the range of 194-210 and 1.0-2.4 μg L-1,...
Energy Harvesting from Cantilever Beam Vibrations in Chaotic State
, M.Sc. Thesis Sharif University of Technology ; Ahmadian, Mohammad Taghi (Supervisor)
Abstract
The need to supply energy of low voltage electronic circuits such as sensors and wireless systems has attracted many researchers in recent years. As a solution to this problem, the energy needed for electronic devices can be obtained from the surrounding environment. An important part of energy harvesters are the systems that use vibrating energy of mechanical devices known as vibration power generators. Most linear vibration generators are systems that operate in resonance mode. As the frequency of the environment moves away from the natural frequency of the generator, the amount of converted energy decreases significantly. For this reason, some solutions are needed to solve this problem. ...
Development of an adaptive surrogate model for production optimization
, Article Journal of Petroleum Science and Engineering ; Volume 133 , September , 2015 , Pages 677-688 ; 09204105 (ISSN) ; Haghighat Sefat, M ; Jamshidi, S ; Sharif University of Technology
Elsevier
2015
Abstract
Recently production optimization has gained increasing interest in the petroleum industry. The most computationally expensive part of the production optimization process is the evaluation of the objective function performed by a numerical reservoir simulator. Employing surrogate models (a.k.a. proxy models) as a substitute for the reservoir simulator is proposed for alleviating this high computational cost.In this study, a novel approach for constructing adaptive surrogate models with application in production optimization problem is proposed. A dynamic Artificial Neural Networks (ANNs) is employed as the approximation function while the training is performed using an adaptive sampling...
Porous eco–friendly fibers for on–line micro solid–phase extraction of nonsteroidal anti–inflammatory drugs from urine and plasma samples
, Article Journal of Chromatography A ; Volume 1574 , 2018 , Pages 18-26 ; 00219673 (ISSN) ; Behkami, S ; Bagheri, H ; Sharif University of Technology
Elsevier B.V
2018
Abstract
In this study, cellulose acetate (CA) fibers were prepared using different solvent systems in electrospinning. The recorded scanning electron microscopy micrographs indicated that the morphology of the prepared fibers is closely associated with the type of electrospinning solvents. The prepared CA fibers were used as an extractive phase for on–line micro–solid phase extraction (μ-SPE) of nonsteroidal–inflammatory drugs (NSAIDs) in biological samples pursued by HPLC–UV determination. Work conducted on this research ascertained that the use of dichloromethane:acetone (3:1, v/v) solvent system in the CA dissolution for electrospinning, leads to the formation of porous ribbon–like fibers and...
Using Game Theory to Battle Jammer in Control Channel of Ad-hoc Cognitive Radio Networks
, M.Sc. Thesis Sharif University of Technology ; Salehi, Javad (Supervisor)
Abstract
Due to both dynamic and opportunistic spectrum access, Cognitive radio networks is a promising solution for spectrum scarcity problem. In cognitive radio networks, users need to have a control channels in order to cooperate for sharing the sensing information, channel sharing and etc. In Ad-hoc cognitive radio networks because of the absence of infrastructure and central nodes, every user runs a distributed algorithm to create a common control channel. If the control channel gets jammed, network’s performance degrades dramatically, therefore the jammer’s target in cognitive radio networks is the control channels to disturb the networks’ performance. The traditional solution to confront...
Graphene oxide-starch-based micro-solid phase extraction of antibiotic residues from milk samples
, Article Journal of Chromatography A ; Volume 1591 , 2019 , Pages 7-14 ; 00219673 (ISSN) ; Behkami, S ; Raoofi, M ; Bagheri, H ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In this study, a method was described for the extraction of three antibiotic residues from cow milk samples using a graphene oxide–starch–based nanocomposite. The prepared nanocomposites were employed as an extractive phase for micro-solid phase extraction of antibiotics from cow milk samples. The extracted antibiotics, i.e. amoxicillin, ampicillin and cloxacillin, were subsequently analyzed by high-performance liquid chromatography–ultraviolet detection (HPLC–UV). Important variables associated with the extraction and desorption efficiency were optimized. High extraction efficiencies for the selected antibiotics were conveniently achieved using the starch–based nanocomposite as the...
Quaternion based linear time-varying model predictive attitude control for satellites with two reaction wheels
, Article Aerospace Science and Technology ; Volume 98 , March , 2020 ; ISSN: 12709638 ; Nejat Pishkenari, H ; Salarieh, H ; Abdollahi, T ; Sharif University of Technology
Elsevier Masson SAS
2020
Abstract
Attitude control of a satellite having only two reaction wheels is a challenging issue. To address this problem, previously published researches considered some simplifying assumptions on the satellites such as diagonality of the moment of the inertia matrix. On the other hand, in some works, the total angular momentum of the satellite is assumed to be zero. In this paper, a linear time-variant model predictive control (LTV MPC) is designed to control a satellite with two reaction wheels. This control method can be applied to a satellite with a non-diagonal inertial matrix in the presence of external torques, to rotate the satellite toward the desired directions in the space and orbit. The...
Improvement of Production Prediction in Reservoir Simulation Using Artificial Neural Networks
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Saeid (Supervisor) ; Badakhshan, Amir (Supervisor)
Abstract
By far, the most expensive part of the production optimization process is the evaluation of the objective function because this requires computationally expensive reservoir simulations to be performed.One way to reduce this high computational cost isby using surrogates or proxies for the reservoir simulator. There are different methods for constructing a surrogate that their aims are mimicking the reservoir behavior with high accuracy and low computational cost. In reservoir engineering surrogate modeling has been used for the problem of well placement optimization,while in the context of production optimization it has not yet been investigated in the literature. Moreover, most of surrogate...
Development of a Model to Evaluate the Social Aspects of Energy System (Case study: Residential Sector)
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor) ; Khajehpour, Hossein (Supervisor)
Abstract
Overcoming environmental problems caused by fossil fuel consumption and responding to the increasing energy demand creates the need for energy systems to transition towards low-carbon systems. The residential sector, as one of the sub-sectors of demand, accounts for a significant fraction of energy consumption, especially for heating and cooling. To achieve sustainable development goals, energy consumption management in this sector is essential. The use of high-efficiency appliances is a determining factor in demand and one of the most important requirements for energy consumption management. However, most energy system models include economic characteristics of technologies and do not...
Experimental investigation of the effects of corona wind on the performance of an air-cooled PV/T
, Article Renewable Energy ; Volume 127 , 2018 , Pages 284-297 ; 09601481 (ISSN) ; Kasaeian, A ; Amidpour, M ; Nasirivatan, S ; Mousavi, S ; Sharif University of Technology
2018
Abstract
In the present study, enhancing the heat transfer is experimentally investigated by the electro-hydrodynamics (EHD) through a single-pass air-cooled PV/T (Photovoltaic/Thermal System). The corona wind increases the heat transfer coefficient by producing a secondary flow and vortex, and consequently, increases the PV/T system efficiency. The effects of the corona wind are studied by changing the voltage values and the flow rates in the air channel. The results show that the corona wind is effective on enhancing the system performance; so that the heat transfer coefficient increases by 65% in natural flow regime by applying 11 kV voltage in the pilot setup. Totally, the thermal efficiency of...
Nanostructured molybdenum oxide in a 3D metal organic framework and in a 2D polyoxometalate network for extraction of chlorinated benzenes prior to their quantification by GC–MS
, Article Microchimica Acta ; Volume 185, Issue 12 , 2018 ; 00263672 (ISSN) ; Karimi Zandian, F ; Javanmardi, H ; Abbasi, A ; Golzari Aqda, T ; Sharif University of Technology
2018
Abstract
A three–dimensional metal organic framework (3D–MOF) and a two–dimensional polyoxometalate (2D–POM), both incorporating nanostructured molybdenum (VI) oxide, were synthesized and implemented for headspace needle trap extraction of traces of chlorobenzenes (CBs). The 3D–MOF of type {(Mo2O6)(4,4′–bpy)}n and the 2D–POM of type [4,4′–bpy][Mo7O22] were synthesized by a solvothermal process and characterized by FT–IR, powder X–ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetry, energy dispersive X–ray, elemental mapping and Brunner–Emmet–Teller adsorption analyses. The 3D–MOF proved to be superior. Following thermal desorption, the CBs...
A comparative study on the performance of HFO-1234yf and HFC-134a as an alternative in automotive air conditioning systems
, Article Applied Thermal Engineering ; Volume 110 , 2017 , Pages 1091-1100 ; 13594311 (ISSN) ; Kasaeian, A ; Golzari, S ; Mahian, O ; Nasirivatan, S ; Wongwises, S ; Sharif University of Technology
2017
Abstract
In this study, an automotive air conditioning system is simulated by considering HFO-1234yf (2,3,3,3-tetrafluoropropene) as the drop-in replacement of HFC-134a. The simulated air conditioning system consists of a multi-louvered fin and flat-plate type evaporator, a wobble-plate type compressor, a mini-channel parallel-flow type condenser and a thermostatic expansion valve. The thermodynamic properties of the refrigerants are extracted from the REFPROP 8.0 software, and a computer program is simulated for the thermodynamic analysis. Two different conditions have been considered in this program for the cycle analysis: for the first state, the cooling capacity is taken as constant, and for the...
Electrospun nanofibers
, Article Solid-Phase Extraction ; 2019 , Pages 311-339 ; 9780128169063 (ISBN) ; Rezvani, O ; Zeinali, S ; Asgari, S ; Golzari Aqda, T ; Manshaei, F ; Sharif University of Technology
Elsevier
2019
Abstract
Electrostatic fiber fabrication technique has evinced more interest and attention in recent years, owing to its versatility, reliability, and potential for applications in diverse fields, particularly separation, extraction, and filtration. The sub-micro fibers are generated by employing strong electric field on polymeric solutions or melt is led to the soft nanometric mats. So far, more than 100 polymers have been Electrospun and this number is gradually increasing. Over recent decades, a remarkable variety of electrospun nanofibers as promising and authentic extracting platforms have been synthesized. They offer various advantages including high surface area-to-volume ratio and tunable...
Technical English for mechanical engineers
, Book ; Meghdari,Ali
Sharif University Press
2014
Abstract
Local educational institutions produce in-house English for Specific Purpose (ESP) materials according to the curriculum policies designated and developed by the Ministry of Higher Education In Iran. To this end, this book aims to be used in the Iranian setting at the tertiary level for undergraduate students majoring in Mechanical Engineering. Moreover, the style of English usage in this ESP textbook is American.
Regarding the content of the textbook, it has both thematic organizations in which the topics are relevant and includes sufficient treatment of the target language areas necessary for the students. The principle organizing approach of this textbook is theme-based. In addition,...
Regarding the content of the textbook, it has both thematic organizations in which the topics are relevant and includes sufficient treatment of the target language areas necessary for the students. The principle organizing approach of this textbook is theme-based. In addition,...
Feedback control of the neuro-musculoskeletal system in a forward dynamics simulation of stair locomotion [electronic resource]
, Article Proc. of IMechE Part H: Journal of Engineering in Medicine ; 2009, Vol. 223, No. 6, pp. 663-675 Journal of NeuroEngineering and Rehabilitation ; Volume 11, Issue 1, 30 April 2014, Article number 78 ; Meghdari, Ali ; Vossough, Gholam Reza ; Sharif University of Technology
Abstract
The aim of this study is to employ feedback control loops to provide a stable forward dynamics simulation of human movement under repeated position constraint conditions in the environment, particularly during stair climbing. A ten-degrees-of-freedom skeletal model containing 18 Hill-type musculotendon actuators per leg was employed to simulate the model in the sagittal plane. The postural tracking and obstacle avoidance were provided by the proportional—integral—derivative controller according to the modulation of the time rate change of the joint kinematics. The stability of the model was maintained by controlling the velocity of the body's centre of mass according to the desired centre of...
Design and Construction of a Soft Actuated Exoskeleton for Hand Rehabilitation of Stroke Patients
, M.Sc. Thesis Sharif University of Technology ; Ghafari, Ali (Supervisor) ; Meghdari, Ali (Supervisor)
Abstract
The main goal of this thesis is the design and development of a rehabilitation device for helping patients “to improve blood circulation” & retain and recover their abilities if possible that were lost during the stroke or a accident like that (my research in karaj/iran shows that it is possible by just movement of the specific body part). The focus is on hand in this thesis because Injuries to the hand are common and can be very debilitating since our hands are our primary means for interacting with our world. For rehabilitation in case of human hand there are several practices that should be done for patients either in home or in a rehabilitation center, time and money that is supposed to...
Silica chloride/wet SiO2 as a novel heterogeneous system for the deprotection of acetals under mild conditions [electronic resource]
, Article Phosphorus, Sulfur, and Silicon and the Related Elements ; Volume 178:2667-2670, Issue 12, 2003 ; Pourjavadi, Ali ; Zolfigol, Mohammad Ali ; Bamoniri, Abdolhamid
Abstract
A combination of silica chloride and wet SiO2 was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives under mild and heterogeneous condition
Earthquake Branch
, M.Sc. Thesis Sharif University of Technology ; Bakhshi, Ali (Supervisor)
Abstract
In the past few decades, shaking tables are widely used to evaluate system response of structures under seismic excitations. These devices are used without any fundamental research performed on a shaking table system as an entity model. In most of these studies for simplicity, it is assumed that there exist no considerable vibration and displacement around the shaking tables, and no attention is paid to the peripheral substances such as soil settled under the foundation.
In this thesis, result of ambient vibration test on shaking table system (solid deck, concrete foundation and soil layer) has been presented. Precise sensors known as low frequency and high accuracy accelerometers have...
In this thesis, result of ambient vibration test on shaking table system (solid deck, concrete foundation and soil layer) has been presented. Precise sensors known as low frequency and high accuracy accelerometers have...