Loading...
Search for:
karimi--jalal
0.113 seconds
Total 572 records
Study on Very High Energy Cosmic Ray at Tehran Surface
, Ph.D. Dissertation Sharif University of Technology ; Samimi, Jalal (Supervisor)
Abstract
The cosmic ray astronomy was born in 1937 when Victor Hess flied with his balloon to the height of 17,500 feet. He found that the cosmic rays come from out of atmosphere. There are three fundamental questions from that time. The goal of all cosmic ray's experimental activities and related theories is finding out the answer of these questions. The first question is about the energy and composition spectrum of cosmic rays. The second one is finding the sources which can product the very high energy particles such as the protons with the energy of 1021eV found in some observatory such as AGASA and Haverah Park. The last question is the process of diffusion of cosmic rays in the galaxy. One of...
Designing a Model-Based Process and Architecture for Partial Automation of Software Development
, M.Sc. Thesis Sharif University of Technology ; Habibi, Jafar (Supervisor)
Abstract
Automation of the software development process is the software engineers' final goal, but with the current facilities and knowledge in software engineering, it is not possible to automatically generate the whole software. Usually all the software in a specific domain contain common behaviors, which by careful exploration of these common behaviors and automation of code generation in these sections, the cost and time of projects' execution can be reduced. According to Model Driven Development (MDD), the first step in software development is creating appropriate models. For creating models, metamodel is required; therefore, we need to create a specific motamodel for the chosen domain or use...
Travel Mode Choice with High Occupancy Toll Lane
, M.Sc. Thesis Sharif University of Technology ; Samimi, Jalal (Supervisor)
Abstract
With the growth of the urban population and the increase in private car ownership, negative implications of transportation, such as traffic congestion and environmental pollution has increased. A good solution to this problem is development of traffic infrastructures. However, it is not sufficient by itself and better management strategies for solving these problems are needed. One of the related approaches, is high occupancy toll lane. The main purpose of this study is modeling user’s mode choice behavior in the presence of high occupancy toll lane and pricing some highway lanes in Tehran. Another important purpose of this study is to find affective factors that have an influence on users...
Experimental Analysis and Simulation of Pollution Distribution in Ground Water and Soil
, M.Sc. Thesis Sharif University of Technology ; Shayegan, Jalal (Supervisor)
Abstract
Underground water is one of major resources of drinking water in Iran and thus, its quality (in terms of absence of pollutants) is a matter of great importance. The main goal of this research was to investigate the pollution concentration in underground water and soil in two regions: Dasht-e-naz in Sari and the fields near Sarkhoun gas refinery. The second goal was to determine the source and measure the distribution of the pollutants (in case of presence) and determine potential risks caused by them. The first step was to perform experimental tests in the two regions. In Sari's Dasht-e-naz region, a number of wells were chosen for sampling according to the direction of underground water...
Bioleaching of Heavy Metal from Industrial Incinerator Ash
, M.Sc. Thesis Sharif University of Technology ; Shayegan, Jalal (Supervisor)
Abstract
This study focused on the investigation of bioleaching of heavy metals from incinerator ash using Thiobacillus thiooxidans. Eight factors were examined for their significance on bioleaching using a Placket-Burman factorial design. Four significant variables (pulp density, Initial pH, sulfur Concentration and inoculation amount) were selected for the optimization studies. The combined effect of these variables on metal bioleaching was studied using a central composite design. Second order polynomials were established to identify the relationship between the recovery percent of the metals and the four significant variables. The optimal values of the variables for maximum metals bioleaching...
Designing Granular Sequencing Batch Reactor for Investigating the Effect of Influent Feeding Alkalinity and Rreactor pH on Aerobic Granulation
, M.Sc. Thesis Sharif University of Technology ; Shaygan, Jalal (Supervisor)
Abstract
Laboratory experiments were carried out to investigate the effect of influent alkalinity and reactor pH on microbial species, morphology and performance efficiency of aerobic granules. The experiments were conducted in two L sequencing batch reactors (R1-R2) with different influent alkalinity and pH medium. pH in R1 ,with high influent alkalinity, was in the range of 7-7.5 and pH in R2 was adjusted in 4.5-5.5. The experimental results demonstrated that the dominated microbial species and structure of granules were different in two rectors. Acidic environment of R2 provide favorable condition for fungal growth and granules formed within first week of operation. On the other hand in R1,...
Sttudy of Effective Parameters on Biodegradation of Organic Waste
, M.Sc. Thesis Sharif University of Technology ; Shayegan, Jalal (Supervisor)
Abstract
With the increasing population and expanding urbanization and changing consumption patterns and relative prosperity increases, the amount of waste generated has increased significantly. So the municipal waste management as one of the challenges that lie ahead for municipal and state has become. Therefore, different approaches have been proposed to solve this problem. In the past government used landfill or incineration program for waste management. Given the risks to the environment and human health are two ways to create and large amount of biodegradable solid waste, composting seems to be good approach for waste management. With using the process on an industrial scale by municipalities,...
Simulation of continuous catalytic conversion of glycerol into lactic acid in a microreactor system: A CFD study
, Article Journal of Industrial and Engineering Chemistry ; Volume 104 , 2021 , Pages 258-271 ; 1226086X (ISSN) ; Kazemeini, M ; Sadjadi, S ; Sharif University of Technology
Korean Society of Industrial Engineering Chemistry
2021
Abstract
Hand in hand with the flourish of the biodiesel industry, glycerol (GLY) as an inconvenient by-product has generated environmental and sustainability concerns. Devising measures for efficient transformation of GLY into value-added products is a promising solution. In this contribution, the transformation of GLY to lactic acid (LA) as a valuable chemical was investigated in a continuous process for industrial applications. In this regard, a catalytic method using heterogeneous Cu nanoparticles in NaOH solution was studied in a microreactor by a CFD simulation. A seven-inlet micromixer comprising an optimized mixing unit was incorporated for uniform distribution of the species. The effects of...
Modeling a Solar Refrigerator Powered by Energy Storage System
,
M.Sc. Thesis
Sharif University of Technology
;
Samimi, Jalal
(Supervisor)
;
Vesaghi, Mohamd Ali
(Supervisor)
Abstract
Considering high potential of solar energy and exhaustibility of fossil fuels in Iran, using solar energy seems to be inevitable. But one of the main problems in the application of these systems is high investment and maintenance costs. So, in this thesis, suitable solution is presented for decreasing cost and optimizing of a solar absorption refrigerator based on developed energy model. This system consists of two CPC solar collectors and a thermal energy storage system using phase change materials that provides input energy to the generator of absorption refrigerator. The exergy efficiency of system components is calculated by relations of energy model and exergy analysis. Then...
Optimum Camera Position for UAV Vertical Plane Maneuvers
,
M.Sc. Thesis
Sharif University of Technology
;
Malaek, Mohammad Bagher
(Supervisor)
Abstract
This work presents the methodology to investigate Optimum Camera Installation Angle (OCIA)while employing the so called?Vision Based Navigation (VBN)? in urban areas.The approach is suitable for future general aviation aircraft as envisioned in Small Air Transportation System (SATS) as well as Unmanned Aerial Vehicles (UAV).Due to practical constraints, the work is limited to the maneuvers in the vertical plane while conducting Simultaneous Localization and Mapping (SLAM) technique.This technique was originated in robotics and is commonly used to guide both ground based and low speed aerial robots in unknown environments involving different types of obstacles. A variety of camera...
Particle Acceleration in Astrophysical Shock Waves and Laser-Induced Plasma Waves and its Simulation
, Ph.D. Dissertation Sharif University of Technology ; Anvari, Abbas (Supervisor) ; Samimi, Jalal (Supervisor)
Abstract
In this thesis, plasam kinetic aspects causing production of high-energy super-thermal particles in strongly nonlinear perturbations, including relativistic electron waves and shock waves occurred respectively in astrophysical and laser produced plasmas, have been studeied. Importance of kinetic simulations in this area has been demonstrated. In this respect, passing serious challenges, we have prepared a kinetic particle-in-cell (PIC) code and applied it within our supplied computational-resources. Relativistic electron waves produced via interaction of laser with tenouse plasmas have been deeply studied. These studies have resulted in new findings in fluid description of these waves,...
Production of Lactic Acid from Glycerol in Microchannel Reactors in the Presence of Copper-Based Catalysts
, M.Sc. Thesis Sharif University of Technology ; Kazemeini, Mohammad (Supervisor) ; Sadjadi, Samaheh (Supervisor)
Abstract
Hand in hand with the flourish of the biodiesel industries, glycerol has turned into an abundant waste chemical posing obstacles to their large-scale implementation. Devising measures for efficient transformation of glycerol into value added products is a promising alternative to its large-scale disposal into the nature that would also increase the competitiveness of biodiesel fuels. In this study, production of lactic acid (LA) as a valuable chemical with wide applicability is studied in a continuous process with glycerol as a cheap and convenient feedstock. In this regard, the state-of-the-art approaches in catalytic conversion of glycerol to LA are reviewed. A catalytic method using...
Infrared Structure of Gravity and Information Paradox of Black Holes
, M.Sc. Thesis Sharif University of Technology ; Faraji Astaneh, Amin (Supervisor)
Abstract
According to general theory of relativity, collapse of matter under gravitational force leads to the formation of black holes. Considering the quantum effect shows that black holes have thermal radiation which cause them to evaporate. After a complete evaporation, the state of radiation can not contain all information of initial matter. In other word, this process does not obey unitary evolution of quantum mechanics. This is called the black hole information paradox, which has been one of the most challenging problem of theoretical physics for several recent decades. Recently, a deep connections between asymptotic symmetries, soft graviton theorem and gravitational memory effect has been...
Optimal Design of Partial State-Feedback Controllers
, M.Sc. Thesis Sharif University of Technology ; Karimi, Houshang (Supervisor) ; Karimi, Masoud (Supervisor)
Abstract
Design of optimal controllers for nonlinear systems and even for linear systems is one of the most important parts of the control science. In optimal controller design, our aim is to maximize or minimize some kind of cost function associated with that particular problem. Such cost functions are usually combining the overall control effort, system’s energy, or some other important specifications of the system. Explicit solution for linear quadratic controllers exists under some mild conditions such as stabilizability of the system. The solution is in the form of a full state-feedback law. But in practical problems, we may not have access to all of the system state variables. The problem can...
An Investigation into the Hot Tensile Properties of a Heat Resistant Steel
, M.Sc. Thesis Sharif University of Technology ; Karimi Taheri, Ali (Supervisor)
Abstract
The microstructures of stainless steels consist of an austenitic matrix with almost continuous network of primery carbides.This class of steel had replaced the traditional super alloys with a reduction in costs and has similar properties under conditions of creep, which is one of the principal degradation mechanisms leading to failure in service at elevated temperaturs , therefore, their mechanical properties such as tensile strength and creep resistance are particularly important in hot deformation. Recently the effects of temperature and aging time on static strain aging in worked stainless steel have been investigated. In this study the deformation behavior of HP-series austenitic...
Decentralized adaptive control of large-scale affine and nonaffine nonlinear systems
, Article IEEE Transactions on Instrumentation and Measurement ; Volume 58, Issue 8 , 2009 , Pages 2459-2467 ; 00189456 (ISSN) ; Menhaj, M. B ; Karimi Ghartemani, M ; Saboori, I ; Sharif University of Technology
2009
Abstract
This paper presents a decentralized adaptive control design for a class of large-scale nonlinear systems with unknown subsystems. When the subsystems are modeled by affine equations, a direct adaptive controller is devised based on the Lyapunov theory, so that the stability of the closed-loop system is guaranteed by introducing a suitably driven adaptive rule. A neuro-based structure is proposed when the subsystems are nonaffine, and the stability analysis is also performed based on the Lyapunov theory. Moreover, the unknown interactions among the subsystems are considered as having a nonlinear function against the simple form considered for the affine case. The proposed controllers are...
, M.Sc. Thesis Sharif University of Technology ; Pourjavadi, Ali (Supervisor) ; Zohurian Mehr, Mohammad Jalal (Supervisor)
Abstract
Polyampholyte hydrogels are hydrophilic networks that contain both positively- and negatively-charged functional groups on their structure. Polysulfobetaines are the most important type of polyampholytes, which have been extensively studied. However, these hydrogels exhibited poor gel strength causing limitation of their applications. Consequently, much attention has been focused on the preparation of nanocomposite hydrogels with high gel strength and lower cost using organomodified clays. In this project, Novel polyampholytic superabsorbing nanocomposites based on the zwitterionic sulfobetaine monomer [3-(methacrylamido)propyl)]dimethyl(3-sulfopropyl) ammonium hydroxide (MPDSAH) were...
Modeling the Solar Heat Pump with an Energy Storage System
, M.Sc. Thesis Sharif University of Technology ; Samimi , Jalal (Supervisor) ; Vesaghi, Mohammad Ali (Supervisor)
Abstract
Purpose of ongoing thesis is providing a tool for suitable modeling, increase efficiency and decrease construction cost of solar absorption heat pump. At first, the solar absorption heat pump is modeled by the thermodynamic laws. Then, this model is converted to the new standard mathematical programming model using exergy and thermodynamic Analysis with considering all technical and economic constrains. This mathematical model is optimized by Genetic algorithm (GA). Because of the nonlinear objective function and the constraint, GA is used as optimization algorithm. After applying GA, optimized parameters of cycle heat exchanger designing and its electricity consumption are calculated....
Decentralized Control of a Multi-DG Microgrid in Islanded Mode of Operation
, M.Sc. Thesis Sharif University of Technology ; Karimi, Houshang (Supervisor) ; Karimi, Masoud (Supervisor)
Abstract
A control strategy for islanded (autonomous) operation of a microgrid consisting of two Distributed Generation (DG) units is proposed in this thesis. The DG units are connected together in a radial configuration. Each DG unit utilizes a voltage-sourced converter (VSC) to interface to its dedicated load. The DG units and the loads are to operate in the islanded mode of operation. To provide autonomous operation for the microgrid, voltage and frequency of the loads should be regulated. The proposed control strategy utilizes (i) an internal oscillator for frequency control in an open loop manner and (ii) a decentralized servomechanism controller to regulate the load voltage. The microgrid is...
Nonlinear adaptive control of grid-connected three-phase inverters for renewable energy applications
, Article International Journal of Control ; 2015 ; 00207179 (ISSN) ; Namvar, M ; Karimi, H ; Piya, P ; Karimi Ghartemani, M ; Sharif University of Technology
2015
Abstract
Distributed generation (DG) units are often interfaced to the main grid using power electronic converters including voltage-source converters (VSCs). A VSC offers dc/ac power conversion, high controllability, and fast dynamic response. Because of nonlinearities, uncertainties, and system parameters’ changes involved in the nature of a grid-connected renewable DG system, conventional linear control methods cannot completely and efficiently address all control objectives. In this paper, a nonlinear adaptive control scheme based on adaptive backstepping strategy is presented to control the operation of a grid-connected renewable DG unit. As compared to the popular vector control technique, the...