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mozafari--aliasghar
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Optimization of Pulp and Paper Process in Order to Save Energy, Fuel and Capital Investment
, Ph.D. Dissertation Sharif University of Technology ; Farhanieh, Bijan (Supervisor) ; Mozafari, Aliasghar (Supervisor)
Abstract
By applying the Pinch Technology and Exergoeconomic simultaneously, to a complex process system, beneficial and energy-efficient measures are identified.In the present research “Three-link-model” Exergoeconomic methodology optimizes the system and contrary to traditional exergoeconomic methods, reversed method is used. The approach proposed for optimization of such a complex system is to iteratively optimize subsystems. Since assumptions considered by conventional Exergoeconomic for calculating the cost-optimal exergetic efficiency and relative cost difference, are not applicable, new assumptions are to be considered. Unlike traditional Exergoeconomic method, product’s exergetic specific...
Simulating Dynamics of Immiscible Liquids Separation Using Microfluidics
, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Aliasghar (Supervisor)
Abstract
Most of industrial and laboratory processes are faced with liquid-liquid emulsions particularly aqueous-organic ones in their different product streams which determine the need to perform phase separation due to enviromental problems or need to increase the product purity. In this project, due to presence of a water-hexane two phase flow mixture in the outflow of a microractor that performs Lithium-Bromine exchange reaction, a capillary microchip separator has been designed in order to separate water through capillary channel and hexane through main channel outlet using interfacial forces and wettability effects. To obtain a desired phase separation, the pressure drop through main channel...
Seismic behavior of concrete moment frame reinforced with GFRP bars
, Article Composites Part B: Engineering ; Volume 163 , 2019 , Pages 324-338 ; 13598368 (ISSN) ; Khaloo, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In this research, four types of concrete moment frame were designed with glass fiber reinforced polymer (GFRP) bars according to ACI 440.1R-15 and the seismic behavior was assessed using pushover analysis. The frames were three and five stories with two and three bays. A computer code was developed to calculate the amount of fiber reinforced polymer bars in beams of the frames. In order to evaluate nonlinear behavior in plastic hinge regions, sections of beams and columns were analyzed on the basis of moment-curvature diagram and also P-M interaction curve for columns. Performance levels of frames were determined considering ATC-40 criteria. Behavior of concrete moment frames reinforced with...
Synthesis of Silica Nanosheets Using Droplet-based Microfluidics
, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Aliasghar (Supervisor)
Abstract
The main purpose of this project is synthesis of the silica nano-sheets by means of microfluidic techniques. Continuous process, precise control of reaction condition, and higher production rate can be considered as main pros of silica nano-sheets synthesized by microfluidic platforms. General method can be explain as follow: first two oleic and aqueous phase are injected to the microfluidic system, then oleic phase breaks down in aqueous phase drop-wisely and by performing sol-gel reaction on the oil-water interface a silica crust is made on oil droplets. Eventually, oil droplets are left the system and broken down and silica nano-sheets are made. FESEM and microscopic images of...
Using Molecular Dynamics Simulation for Investigation of Sulfuric Compounds Adsorption on Zeolite
, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Aliasghar (Supervisor)
Abstract
There are different sulfur compounds in the crude oil, and after combustion all of these sulfuric compounds produce sulfur dioxide, this sulfur dioxide cause acid rain, deactivation of catalysts and also environmental bad effects. So the amount of sulfur that is released should be controlled and this is done by removing sulfuric compounds before combustion. zeolites as adsorbent of sulfuric compounds has been used widely by researches and had given good results. molecular dynamics simulation as an effective way for describing the behavior of these compounds in the molecular level and in scales of angstrom has been used and the effect of van der waals and electrostatic forces between sorbates...
An approach to optimal dispatch of bilateral electricity contracts regarding voltage stability
, Article Power Plants and Power Systems Control 2006 ; Volume 39, Issue 7 , 2007 , Pages 65-70 ; 9780080466200 (ISBN) ; Ranjbar, A. M ; Mozafari, A ; Amraee, T ; Sharif University of Technology
Elsevier Ltd
2007
Abstract
This chapter proposes a methodology for optimal dispatch of bilateral electricity contracts, which may endanger the system voltage stability in light of short-term operational planning of a deregulated power system. In this framework the value that each owner of a transaction is willing to pay reflects how much the electricity contract is important to be implemented physically. The proposed model dispatches optimally the bilateral transactions regarding the prices offered by owners of bilateral contracts for reactive power and transmission capacity utilization in one hand and, the total operational costs of reactive power resources in the other hand. The model also includes the limits...
An approach to optimal dispatch of bilateral electricity contracts regarding voltage stability
, Article IFAC Proceedings Volumes (IFAC-PapersOnline) ; Volume 5, Issue PART 1 , 2006 , Pages 65-70 ; 14746670 (ISSN); 9783902661081 (ISBN) ; Ranjbar, A. M ; Mozafari, A ; Amraee, T ; Sharif University of Technology
IFAC Secretariat
2006
Abstract
This paper proposes a methodology for optimal dispatch of bilateral electricity contracts, which may endanger the system voltage stability in light of short-term operational planning of a deregulated power system. In this framework the value that each owner of a transaction is willing to pay will reflect how much the electricity contract is important to be implemented physically. The proposed model dispatches optimally the bilateral transactions regarding the prices offered by owners of bilateral contracts for reactive power and transmission capacity utilization in one hand and, the total operational costs of reactive power resources in the other hand. The model also includes the limits...
Reactive power management in a deregulated power system with considering voltage stability: Particle swarm optimisation approach
, Article Eighteenth International Conference and Exhibition on Electricity Distribution, CIRED 2005, Technical Reports - Session 1: Network Components, Turin, 6 June 2005 through 9 June 2005 ; Volume 6, Issue 2005-11034 , 2005 , Pages 55-58 ; 05379989 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Mozafari, A ; Sharif University of Technology
2005
Effect of compressive glass fiber-reinforced polymer bars on flexural performance of reinforced concrete beams
, Article ACI Structural Journal ; Volume 119, Issue 6 , 2022 , Pages 5-18 ; 08893241 (ISSN) ; Khaloo, A ; Aliasghar Mamaghani, M ; Khaloo, H ; Sharif University of Technology
American Concrete Institute
2022
Abstract
This research studies the effect of glass fiber-reinforced polymer (GFRP) bars as compressive reinforcement in reinforced concrete (RC) beam members. Three singly and six doubly reinforced GFRP-RC beams were tested under a four-point loading configuration. The effect of compressive reinforcement on the load-bearing capacity, ductility, stiffness, and failure mode is determined. Also, the compressive performance of GFRP bars is evaluated by testing GFRP-RC cylinders. According to the results, GFRP bars in compression had a limited contribution to enhancing flexural strength, and the maximum increment in the flexural capacity of doubly reinforced beams compared to singly reinforced specimens...
Aqueous Phase Reforming of Biomass Using Micro-reactor
, M.Sc. Thesis Sharif University of Technology ; Kazemeini, Mohammad (Supervisor) ; Mohammadi, Aliasghar (Supervisor)
Abstract
Consumption of oil and gas as energy carrier leads to irreversible environmental effects related to greenhouse gases emission. Hence, for the reduction in greenhouse gas emission, a shift to renewable resources for energy supply is recommended. However, in recent years, hydrogen has emerged as the most promising clean energy carrier for generating electrical power through fuel cells. Nevertheless, production of renewable hydrogen is the main barrier to the development of hydrogen as an energy carrier. Aqueous phase reforming of oxygenated hydrocarbon is developed by Dumesic for producing renewable hydrogen-rich gas with low CO. Since it is expected that, use of new technology such as the...
Bromine-lithium Exchange Reaction in Organic Synthesis Using Glass Microreactor
, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Aliasghar (Supervisor)
Abstract
Today, microreactors come into focus due to their exclusive characteristics including high surface-to-volume, lower consumption of reagents and fast mixing. In this study, optimization of the Br-Li exchange reaction as a consecutive reaction using glass microreactor is investigated. To construct glass microreactor, laser ablation and thermal bonding method are utilized. In order to find the best yield and selectivity of the reaction, various parameters, such as solvent, equivalent ration of the two reagents, concentration of the reagents, residence time and flow rates of the reagents are examined. In addition, atomic force microscopy (AFM) analysis was used to determine the surface...
Microfluidics Desulfurization of Hydrocarbons Components
, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Aliasghar (Supervisor) ; Kazemeini, Mohammad (Supervisor)
Abstract
Microfluidic is a science and technology in which they study the behavior of fluids, control them and design devices or systems with dimensions of tens to hundreds of micrometers. The technology has the ability to design and manufacture macro-scale and micro-scale equipment, such as micro-pumps, micro-valves, micro-filters, micro-mixers, micro-reactors, and other equipment. The benefits of this technology include the use of low sample size, low waste of energy, low power consumption, short response time, high system performance, portability and performance of several operating phases in a compressed piece such as production, isolation and analysis. Also, the very low amount of chemicals and...
Preparation and Performance Assessment of Polymer-SAPO-34 Mixed Matrix Membrane for Separation of CO2 from Other Gases
,
M.Sc. Thesis
Sharif University of Technology
;
Soltanieh, Mohammad
(Supervisor)
;
Mohammadi, Aliasghar
(Supervisor)
Abstract
In this research incorporation of SAPO-34 zeolite filler into polycarbonate membrane was investigated for fabrication of mixed matrix membrane (MMM). The main purpose of addition of zeolite in polymer matrix is to enhance the separation properties of pure membrane by means of the selective pores of SAPO-34. SAPO-34 possesses pores with proper size for separation of CO2 from CH4 by molecular sieving mechanism. Pure polycarbonate membrane and PC/SAPO-34 MMM was prepared by solvent evaporation method using dichloromethane as solvent. Zeolite loading was varied between 5-30%wt. First of all, polycarbonate was characterized by DSC, FTIR and viscometer analysis in order to determine all the...
Improvement of Corrosion Resistance of Concrete Sewer Pipes Against Microbial Corrosion
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdollah (Supervisor)
Abstract
Microbiologically Influenced Corrosion (MIC) of concrete sewer ptpes and wastewater collection systems has been reported in many places of the world. Recently, numerous copper compounds have been used for bacterial growth control in sewer pipes. In this thesis, bath parameterswere optimized in order to maximize copper osmosis to the porous concrete matrix.Concrete pipes were electrochemically coated inCopper Lactate bath in a constant current mode (1=0.6 A), while temperature was set to 25, 50, 75 and 95
°Cand pH to 9,10 and 11. Specimens were then characterized by scanning electron
microscopy, optical microscopy, XRD andAAS. Copper Osmosis was highest in pH=9 and...
°Cand pH to 9,10 and 11. Specimens were then characterized by scanning electron
microscopy, optical microscopy, XRD andAAS. Copper Osmosis was highest in pH=9 and...
Solving the Network Design Problem by Surrogate Functions and Lower and Upper Bounds on the Objective Function at Different Levels of Budget
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
The purpose of this research is to provide a method for finding a “good” solution to the network design problem with less computational efforts, faster than the existing conventional methods of solving this problem. Network design problem is the problem of selecting a subset of projects from a set of alternative projects so that to optimize the objective function (e.g., the total travel time in the network) subject to the set of existing constraints (e.g., budget). Due to the combinatorial and non-convex nature of the problem, its solution could be very cumbersome and time-consuming. Various methods have been proposed to solve this problem efficiently, providing good solutions at high...
Seizure Detection in Generalized and Focal Seizure from EEG Signals
, M.Sc. Thesis Sharif University of Technology ; Hajipour, Sepideh (Supervisor)
Abstract
Epilepsy is one of the diseases that affects the quality of life of epileptic patients. Epileptic patients lose control during epileptic seizures and are more likely to face problems. Designing and creating a seizure detection system can reduce casualties from epileptic attacks. In this study, we present an automatic method that reduces the artifact from the raw signals, and then classifies the seizure and non-seizure epochs. At all stages, it is assumed that no information is available about the patient and this detection is made only based on the information of other patients. The data from this study were recorded in Temple Hospital and the recording conditions were not controlled, so...
Investigation on Wettability Alteration of Reservoir Rocks by Functionalized Silica Nanoparticles using Molecular Dynamics Simulations
, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Aliasghar (Supervisor) ; Seyfkordi, Aliakbar (Supervisor)
Abstract
The properties of 3 nm-diameter fluorinated silica nanoparticles with different coverage percent of CF3 groups as water and oil repellents were investigated at the water-rock and decane-rock interface using molecular dynamics simulation. Simulating a pore of rock in presence of water and decane molecules separately, resulted in liquid bridging for both of liquids. The density profiles of liquids in the pore clearly show several highly ordered layers packing of the molecules close to the rock surface. Distribution of liquid molecules around the nanoparticles is much influenced with increasing CF3 groups on the nanoparticle surface. Results show that adsorption of functionalized silica...
Effects of regeneration heat exchanger on entropy, electricity cost, and environmental pollution produced by micro gas turbine system
, Article International Journal of Green Energy ; Volume 9, Issue 1 , Jan , 2012 , Pages 51-70 ; 15435075 (ISSN) ; Ehyaei, M. A ; Sharif University of Technology
2012
Abstract
A new method has been employed in this research that optimizes a power generation system by maximizing the first and second law efficiencies and minimizing the entropy generation. Mass flow rates of pollutants and related external social cost of air pollution have been considered in estimating the electricity production cost. The effects of regenerative and CHP heat exchangers on power production, efficiencies, and production cost have been evaluated. The results show that a single regenerative heat exchanger lowers NOx, CO, and CO 2 emissions by 15%, 40%, and 0.4%, respectively, and decreases the electricity production cost by nearly 18%. A single CHP heat exchanger has little influence on...
A new type of hybrid features for human detection
, Article Proceedings - 2012 IEEE 8th International Conference on Intelligent Computer Communication and Processing, ICCP 2012 ; 2012 , Pages 237-240 ; 9781467329514 (ISBN) ; Jamzad, M ; Sharif University of Technology
2012
Abstract
Human detection is one of the hard problems in object detection field. There are many challenges like variation in human pose, different clothes, non-uniform illumination, cluttered background and occlusion which make this problem much harder than other object detection problems. Defining good features, which can be robust to this wide range of variations, is still an open issue in this field. To overcome this challenge, in this paper we proposed a new set of hybrid features. We combined the Histogram of Oriented Gradient (HOG) with the new features called Histogram of Small Edges (HOSE) which is introduced in this paper. These two kinds of features have two different approaches for...
Automatic epileptic seizure detection in a mixed generalized and focal seizure dataset
, Article 26th National and 4th International Iranian Conference on Biomedical Engineering, ICBME 2019, 27 November 2019 through 28 November 2019 ; 2019 , Pages 172-176 ; 9781728156637 (ISBN) ; Hajipour Sardouie, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Detection of seizure periods in an epileptic patient is an important part of health care. However, due to the variety in types of seizures and location of them, real-time seizure detection is not straight forward. In this paper, we propose a method for seizure detection from EEG signals in datasets which have both generalized and focal seizures. The proposed method is useful in the situations that we have no prior knowledge about the location of the patient's seizure and the pattern of evolution of seizure location. In the proposed method, first, the artifacts are automatically reduced by Blind Source Separation (BSS) methods. Then, the channels are clustered into two clusters. After that,...