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khaksari-noori--mohammad
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An Investigation on Microstructure and Mechanical Properties of TLP Bonded Al/SiC Composite Using Powder Technique
, M.Sc. Thesis Sharif University of Technology ; Ekrami, A.A (Supervisor) ; Bagheri, REZA (Supervisor)
Abstract
In this research Al6061-SiC composite bonding was done by transient liquid phase method using powder copper intermediate layer. In the first stage feasibility of making this junction in ambient condition was studied. In order to find process optimum temperature, experiments were performed in 560°C, 570°C, 580°C and 590°C for 2 hours. Optical microscopy, scanning electron microscopy and EDS analysis were utilized for this study. Moreover, shear strength determination test was done to assess and compare mechanical properties and also to determine the optimum bonding temperature.
In second stage, base composite and bonded specimens were homogenized in 530°C for 5 and 10 hours. Effect of...
In second stage, base composite and bonded specimens were homogenized in 530°C for 5 and 10 hours. Effect of...
Determining the Optimal Irrigation Pattern in Agricultural Areas Using a Combination of Remote Sensing Data and the Development of a Lump Soil Moisture Model
, M.Sc. Thesis Sharif University of Technology ; Danesh-Yazdi, Mohammad (Supervisor)
Abstract
The purpose of this study is to introduce a new indicator to estimate the amount of irrigation water in excess of the need and also to determine the optimal irrigation pattern to reduce water loss in agriculture. According to the Food and Agriculture Organization of the United Nations, the major loss of fresh water takes place in agriculture, and the reduction of water resources is more significant in developing countries that do not have advanced agricultural equipment. One of the challenges in the studies related to reducing the amount of water used in agriculture is a lack of knowledge on the spatial distribution and temporal changes in water loss in a region. Although estimation of...
Computational Simulation of Turbulent Film Cooling, Using RANS/LES Hybrid Approach and Digital Filter Based Interface Boundary Conditions
, M.Sc. Thesis Sharif University of Technology ; Taeibi-Rahni, Mohammad (Supervisor)
Abstract
Nowadays, hybrid LES/RANS approach is being widely used by many researchers. This approach uses the advantages of both LES and RANS approaches simultaneously. Hybrid approach is as accurate as LES, but its cost is much lower. The biggest problem of hybrid approach is transformation of data between RANS and LES regions. Before, precursor simulation and synthetic methods, such as Fourier series and synthetic eddy methods (SEM) have been used extensively to solve such problems. Precursor simulation is expensive, because of high cost of generation of data. On the other hand, Fourier series method is confined to simple geometries, while SEM has problem of programming. Interface condition in this...
Inclusion matrices and chains
, Article Journal of Combinatorial Theory. Series A ; Volume 115, Issue 5 , 2008 , Pages 878-887 ; 00973165 (ISSN) ; Khosrovshahi, G. B ; Maysoori, Ch ; Mohammad Noori, M ; Sharif University of Technology
2008
Abstract
Given integers t, k, and v such that 0 ≤ t ≤ k ≤ v, let Wt k (v) be the inclusion matrix of t-subsets vs. k-subsets of a v-set. We modify slightly the concept of standard tableau to study the notion of rank of a finite set of positive integers which was introduced by Frankl. Utilizing this, a decomposition of the poset 2[v] into symmetric skipless chains is given. Based on this decomposition, we construct an inclusion matrix, denoted by Wover(t, -) k (v), which is row-equivalent to Wt k (v). Its Smith normal form is determined. As applications, Wilson's diagonal form of Wt k (v) is obtained as well as a new proof of the well-known theorem on the necessary and sufficient conditions for...
Sellecttiion off Appropriiatte Metthod ffor Technollogy (AcquiisiittiionMethodology and Applicability Study in Automotive and Part Manufacturing Industries)
, M.Sc. Thesis Sharif University of Technology ; Arasti, Mohammad Reza (Supervisor) ; Manteghi, Manouchehr (Supervisor)
Abstract
This research deals with selection of appropriate acquisition method mainly at a firm level. Technology plays a crucial role in firms competetive advantage and should be managed carefully. Management of technology consists of five major functions: Identification, Evaluation & Selection, Acquisition, Exploitation and Protection. From a practical point of view, acquisition is the most important stage of MOT process. Technology can be acquired through different methods. Deciding on technology acquisition method needs three decisions about Mode, Mechanisim and Operional Model to be determined respectively. There are different modes of acquisition such as internal R&D, technology transfer and...
The Linkage of Business Diversification and Corporate-level Technology Strategy the Case Study of Iran Khodro Corporation
,
Ph.D. Dissertation
Sharif University of Technology
;
Arasti, Mohammad Reza
(Supervisor)
;
Tidd, Joe
(Supervisor)
Abstract
This research that examines bi-directional linkage between technology strategy and corporate strategy, addresses both of forward-path and backward-path linkages. In forward path, corporate strategy is the main and starting point and technology has a supporting role for firm’s corporate strategy. On this way, technology strategy is developed based on the corporate overall strategy. On the other way (backward-path), technology (or any other resource in general) is the driving force and basis for corporate strategy. In this way, overall strategy is developed and formulated based on technology strategy. So, this research and its achievements have reported and followed in two distinct parts...
Develop the Multigrid Method to Solve the Hydrodynamics Problems
,
M.Sc. Thesis
Sharif University of Technology
;
Noori, Ali
(Supervisor)
;
Seif, Mohammad Saeed
(Supervisor)
Abstract
In recent years, many advanced Computational Fluid Dynamics (CFD) methods have been developed for accurate and efficient simulation of fluid flow. The application of these methods shows that for sufficient accuracy, the mesh resolution has to be reasonably high. Unfortunately, conventioanal single-grid Navier-Stokes solvers suffer from poor convergence characteristics. For this problem we used Multigrid method to speed up the convergence rate. In this section a code was developed (based on the conventional CFD algorithm) which can solve Navier-Stokes equations on structured grids. It also simulates the free surface by VOF method. Agglomeration multigrid method is used in present study for...
Thermal buckling analysis of piezoelectric functionally graded plates with temperature-dependent properties
, Article Mechanics of Advanced Materials and Structures ; Volume 22, Issue 10 , Nov , 2015 , Pages 864-875 ; 15376494 (ISSN) ; Fereidoon, A ; Khaksari Nouri, M ; Mareishi, S ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
In this study, the thermal buckling analysis of hybrid laminated plates made of two-layered functionally graded materials (FGMs) that are integrated with surface-bonded piezoelectric actuators referred to as (P/FGM)s are investigated. Material properties for both substrate FGM layers and piezoelectric layers are temperature-dependent. Uniform temperature rise as a thermal load and constant applied actuator voltage are considered for this analysis. By definition of four new analytic functions, the five coupled governing stability equations, which are derived based on the first-order shear deformation plate theory, are converted into fourth-order and second-order decoupled partial differential...
Surface Modification of Hemodialysis Membrane for Enhancement of Their Performance
, M.Sc. Thesis Sharif University of Technology ; MoosavI, Abbas (Supervisor) ; Abdekhodaie, Mohammad Jafar (Supervisor)
Abstract
A new technique for surface modification of flat sheet hemodialysis membranes has been investigated. This new strategy presents a dynamic surface modification for membranes in order to assess the hydrophilicity, antifouling, and biocompatibility effects of two functional monomers on dialysis membrane. PSF membranes containing polyvinylpyrrolidone were prepared via phase inversion technique. Afterward, free radical polymerization combined with surface polymerization used to introduce acrylic acid and 2-hydroxyethyl methacrylate onto polysulfone membrane surface. Various monomer concentrations were selected to obtain an optimum condition. Field emission scanning electron microscope (FE-SEM),...
Modification of Surface Nanostructure and Mechanical Properties by Friction Stir Processing in Al 5083 with Al2O3 and Cu Particles
, M.Sc. Thesis Sharif University of Technology ; Kokabi, Amir Hossein (Supervisor) ; Akbarzadeh Changiz, Abbas (Supervisor)
Abstract
Al 5083 is a non-heat treatable alloy that widely used in the aerospace and automotive industry due to its low density and high strength. However, poor wearing behavior and low elastic modulus restrict its engineering applications. Metal matrix composites (MMCs) have advantages of high strength and modulus by reinforcement of second phase. Also, MMCs have excellent dimensional stability, damping capacity and wear, creep and fatigue resistances as compared with the corresponding monolithic alloys. Vast loss in ductility and toughness occurs by non- deformable ceramic reinforcements. For the surface engineering purposes, ceramic particles are added in the surface layers of components, whereas...
Simulatin of Reinforcement Corrosion in Pozzolanic Concrete by Neural Network
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdollah (Supervisor)
Abstract
One of the most important factors of reducing durability of concrete structures is corrosion of steel reinforcement in concrete. In this paper, corrosion behavior of reinforcing steel in concrete is investigated in two different methods of protection based on neural network. As regard the first method, pozzolanic additives with optimized percentage were added to Concrete mix design (the percentage of these additives are 25% Weight of cement of fly ash, Micro silica with 10 percent of weight of cement and 25% of Blast Furnace slag weight of cement). In the second approach of protection, 0/5 percent weight of cement of ferrogard 901 inhibitor is added to basic mix concrete design and the...
Design of an Optimal Site Deployment Procedure in Different Air-Defense Scenarios
, M.Sc. Thesis Sharif University of Technology ; Fathi, Mohsen (Supervisor)
Abstract
One of the most important issues among defense is the increasing of the defense power using present facilities. Therefore, optimal setting and arrangement of equipment by considering different air-to-earth attack of enemy without knowing of properties and capabilities of available systems may not be possible. So, using defense equipment considering properties of them, and paying attention to existence restrictions and effective elements can have an effective role with the design of suitable algorithm.The main purposes of this thesis are: maximization of the efficiency of a defense system against. aerial invader targets, achieving the best arrangement of defense equipment based on suggested...
Numerical Analysis of Drop Motion over a Flat Solid Surface Due to Surface Acoustic Waves, Using Lattice Boltzmann Method
, M.Sc. Thesis Sharif University of Technology ; Mohammad Taiebi Rahni (Supervisor) ; Shams Taleghani, Arash (Co-Supervisor)
Abstract
In recent years, there have been a tremendous research performed in the field of sestems containing small scales. However, besides all advantages of such systems, microfluidic systems have extraordinary difficulties and pumping liquid drops as part of some of these systems has been very important issue. An approach related to flow control is use of surface acoustic waves (SAW), which is known as acoustofluidic device. So far, most researches have only qualitatively investigated acoustic flux phenomenon. On the other hand, computational research is ongoing more emphasizing on accuracy, optimization, and obtaining more detailed physical understanding of SAW applications. Investigation of the...
Solvent Engineering for Preparation of Perovskite Film based on Lead Iodide for Solar Cells Applications
, M.Sc. Thesis Sharif University of Technology ; Seyed Reyhani, Morteza (Supervisor) ; Mohammadi, Mohammad Reza (Supervisor) ; Riahi Noori, Nastaran (Co-Advisor)
Abstract
The microstructure, morphology and quality of the perovskite organic-inorganic layer as an absorber layer in perovskite solar cells has a significant role on the efficiency and energy conversion of the device. Different solvent engineering methods have been employed to prepare the perovskite layer with the desired properties and thier reproducibility have been studied. Herein, we applied a two-step solution approach by solvent engineering method, using solvents such as isopropyl alcohol, acetone and thier mixture, for preparation of lead iodide films. Moreover, their metallurgical and photovoltaic properties were investigated. The impact of solvent engineering, using solvents such as...
Corporate-level technology strategy and its linkage with corporate strategy in multi-business companies: IKCO case study
, Article Technological Forecasting and Social Change ; Volume 122 , 2017 , Pages 243-252 ; 00401625 (ISSN) ; Khaleghi, M ; Noori, J ; Sharif University of Technology
2017
Abstract
This article deals with technology strategy and its linkage with overall strategy at multi-business, diversified groups. In the last two decades, the alignment of technology and business strategy has been one of the important research fields in strategy and technology management literature. These researches has been concentrated on single companies through which different frameworks, models, and decision support tools have been developed and widely utilized by industries. Although multi-business and diversified groups play an important role in national economy of developing countries and need a comprehensive and overall plan for the management of their diversified technological capabilities,...
Transmission of Analog Signals in Fading Channels using HARQ
,
M.Sc. Thesis
Sharif University of Technology
;
Hossein Khalaj, Babak
(Supervisor)
Abstract
In this dissertation we will study the problem of transmitting the information of continuous source over fading channel, especially when the transmitter does not have complete information about the channel status. In this situation we will have a tradeoff between the Quality of received packets and the Reliability in transmissions. To increase the quality of packets, for example, we should increase the quantization, and therefore, the transmission rates at the transmitter. But this will also increase the Error Probability at the receiver. It means that if the receiver gets the transmitted packet, it will have a better estimation of information source, but it is likely that error happens and...
Graph-Based Outlier Detection
, M.Sc. Thesis Sharif University of Technology ; Daneshgar, Amir (Supervisor)
Abstract
One of the most heatedly debated issues in Computer Science is Outlier Detection due to its vast and substantial applications such as credit cards, Image Processing,tax fraud detection, and medical approaches. Consequently, Outlier detection has been researched within various domains and knowledge disciplines. On the other hand, the research attempts have not been sufficient to overcome this critical problem considerably inasmuch as nearly all proposed techniques are associated with a special kind of applications or datasets.Firstly, this thesis attempts to provide a precise definition which not only excludes other one’s drawbacks, but also has its distinctive merits. Three essential...
Flow and Heat Transfer between Two Cylinders with Internal Rotation
, M.Sc. Thesis Sharif University of Technology ; Noori Boroujerdi, Ali (Supervisor)
Abstract
The objective of this project is numerical simulation of air flow and heat transfer between two horizontal concentric cylinders with rotation of inner cylinder and inertia of outer cylinder grooves on the inner cylinder. In this study, the air, meanwhile rotational motion by the inner cylinder will enter into the annular space between two cylinders with certain flow rate. It can be mentioned to cooling of power plant generators, Electric motors and rotating machines among usages of air flow between two cylinders. In this article the objective is calculation of pressure drop and Nusselt number, temperature distribution on the inner cylinder under conditions of constant temperature of...
Biological Regeneration of Used Activated Carbon
, M.Sc. Thesis Sharif University of Technology ; Borghei, Mehdi (Supervisor)
Abstract
Tehran Refinery, as an industrial center that has significant water consumption in Tehran, intends to use the flow of water from the treatment plant south of Tehran after final preparation, with the aim of managing water resources and meeting its needs. And it uses a biological activated carbon (BACF) filter to reduce the DOC concentration. In these filters, the removal of organic matter is performed by the adsorption process as well as the biodegradation process by microorganisms grown on activated carbon. The presence of biofilm leads to continuous bio-regeneration of activated carbon during the water treatment process. Therefore, in this study, by examining the performance of these...
An Empirical Study on the Use of Cross-Project Clones
,
M.Sc. Thesis
Sharif University of Technology
;
Heydar Noori, Abbas
(Supervisor)
Abstract
Code clones are similar code snippets in software projects. Code clones, along with their disadvantages and applications, have long been studied by researchers. In recent years, due to the popularity of open source software, using software development ecosystems such as GitHub have increased dramatically. These ecosystems allow their users to perform high-quality software development without the need for physical presence. A number of previous studies have shown that software is being developed or modified repeatedly and many defects in software projects are duplicates. Finding these recurring codes and defects may be useful for software developers. Given that finding and fixing software...