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fallahpour--ahmad
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The Effect of Zinc Salt in COD Removal in a SAF Bioreactor
, M.Sc. Thesis Sharif University of Technology ; Borghei, Mehdi (Supervisor)
Abstract
One of the most important parts of bacteria growth is specific concentration of nutrients added. Although the trace amount of heavy metals are required for bacteria growth, after a threshold concentration they may cause damage or kill the bacteria. Scientifically speaking, all these trace nutrients should be consider as a profitable source of energy for bacteria growth. There are several studies throughout pondering whether the advantages of using heavy metals, such as Zn, outweigh the drawbacks. It has been proven that heavy metals, especially, zinc salt, can improve microbial growth up to a specific threshold concentration. In this study, two upward submerged aerated reactors, which had 12...
Energy Efficient Routing and Resource Allocation in Optical Networks
, M.Sc. Thesis Sharif University of Technology ; Salehi,Javad (Supervisor)
Abstract
As the Internet traffic grows, the energy efficiency gains more attention as a design factor for the planning and operation of telecommunication networks. Therefore, researchers begin to devise solutions for energy conservation in many scientific disciplines. In this thesis, we focus on the study of energy efficiency in optical transport networks, specially, the newly proposed Spectrum sLICed Elastic optical path (SLICE) networks architecture. First of all, we will introduce energy consuming elements in SLICE networks and their power consumption model. Next, we present a dynamic energy efficient routing and spectrum assignment algorithm (EE-RSA) with regenerator placement (RP) capability for...
Robust Control Behavior for Very Flexible UVA
, M.Sc. Thesis Sharif University of Technology ; Fathi, Mohsen (Supervisor)
Abstract
The purpose of this thesis is to design an appropriate controller of a flexible UAV using robust control theory. In the recent decades, researchers have studied the UAVs that were designed for high altitudes and endurances. The applications of these aircrafts can be refer to for missions such as, intelligence surveillances, reconnaissance and aerial surveys. In order to achieve the objectives, the light weight airplane construction and aerodynamic profile is an essential component. That’s why the wings with a high aspect ratio and flexibility are to be used. At first, the robust control, prerequisites, and different methods have been proposed. The next step is the introduction as unmanned...
Energy-efficient manycast routing and spectrum assignment in elastic optical networks for cloud computing environment
, Article Journal of Lightwave Technology ; Volume 33, Issue 19 , July , 2015 , Pages 4008-4018 ; 07338724 (ISSN) ; Beyranvand, H ; Salehi, J. A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
In this paper, we present an energy-efficient manycast routing and spectrum assignment (EEM-RSA) algorithm in elastic optical networks supporting cloud computing applications. The proposed EEM-RSA is adapted for both static and dynamic scenarios. First, an integer linear programing formulation is derived for energy-efficient manycasting and spectrum assignment; then, the corresponding heuristic methods are proposed. To reduce the energy consumption, inactive (idle) elements are turned off, and in the proposed energy-efficient manycasting heuristic, the number of activated elements are minimized. The power consumption of network elements is modeled by considering a constant overhead for the...
A lab-scale set up for thermal radiation experiments with cold junction compensation
, Article Education for Chemical Engineers ; Volume 7, Issue 4 , 2012 , Pages e203-e209 ; 17497728 (ISSN) ; Farhadi, F ; Fallahpour, N ; Sharif University of Technology
2012
Abstract
The concepts of thermal radiation heat transfer are not tangible for many students. Experiments relied on various parameters can clarify the concepts of this mode of heat transfer.A lab-scale set up is described to study the thermal radiation heat transfer experiments. An electrical circuit of the thermopile sensor is designed and manufactured to provide experimental data.The validity of Inverse Square, Stefan-Boltzmann, and Kirchhoff Laws are investigated experimentally in the setup. Results indicate that, it is necessary to consider temperature shifts in the thermopile cold junction which is a potential source of error. Therefore, the output voltage, corresponding to the sensor...
Spectrum-usage-aware resource allocation and multicast routing in elastic optical networks
, Article 8th International Symposium on Telecommunications, IST 2016, 27 September 2016 through 29 September 2016 ; 2017 , Pages 45-50 ; 9781509034345 (ISBN) ; Beyranvand, H ; Fallahpour, A ; Salehi, J. A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
In this paper, dynamic resource allocation and multicast routing algorithms are proposed for elastic optical networks (EONs). The proposed algorithms find the shortest path trees by modeling either the amount of free spectrum in each link or the link length as the cost function of routing method. The proposed algorithms are simulated in the dynamic operation scenario over the so called US Backbone topology. Simulation results reveal that by considering the cost function of routing algorithm based on the available spectrum in each link will improve the blocking probability while reduce the spectrum efficiency. On the other hand, by considering link length as the cost function, the blocking...
Fast iterative reconstruction algorithm for microwave-induced thermoacoustic imaging
, Article 12th IEEE Biomedical Circuits and Systems Conference, BioCAS 2016, 17 October 2016 through 19 October 2016 ; 2017 , Pages 1-4 ; 9781509029594 (ISBN) ; Allahgholizadeh Haghi, B ; Aliroteh, M. S ; Fallahpour, M ; Arbabian, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
In this paper we propose a fast iterative reconstruction algorithm for microwave-induced thermoacoustic (TA) imaging. Instead of calculating the forward and back projections in real time, we construct a library of the impulse responses of individual pixels in advance. During reconstruction, only covariance calculations are performed to reconstruct the intensity of each pixel. In addition, we propose to use a Wiener filter based-deconvolution to accelerate convergence, enabling even single iteration construction in some scenarios. We validate the proposed method both with simulations as well as experiments. Compared to the time reversal method, the proposed fast iterative reconstruction...
Kinetic behaviour of α-galactosidase produced by Absidia griseola: A comparison between free and immobilized forms of the enzyme
, Article World Journal of Microbiology and Biotechnology ; Volume 18, Issue 7 , 2002 , Pages 649-653 ; 09593993 (ISSN) ; Moazami, N ; Mirdamadi, S ; Mesgarian, R ; Vossoughi, M ; Bakhtiari, M. R ; Sharif University of Technology
2002
Abstract
In this research the characteristics of free (partially purified) and immobilized (mould pellets of Absidia griseola) α-galactosidase have been investigated. Inhibition studies of the enzyme showed that p-nitrophenol and sucrose do not have any inhibitory effect on the enzyme, but that galactose is a competitive inhibitor. In the immobilized form, inhibition was lower than in the free enzyme and the level of inhibition decreased as the temperature increased. The activity and stability of free and immobilized enzyme were investigated with respect to temperature, and the results showed that the optimal temperature range of the free enzyme was 45-50°C, while the immobilized enzyme had an...
Manufacture of Smart Drug Delivery System with UCST Polymers
, M.Sc. Thesis Sharif University of Technology ; Ramazani, Ahmad (Supervisor)
Abstract
Smart heat-sensitive polymers play a unique role in drug delivery systems due to reversible behavior in response to environmental changes, especially temperature changes. Among the heat-sensitive polymers, UCST polymers due to their specific behavior and very little-known polymers with this feature are the subject of many new researches. In the present study, New designed temperature-sensitive polymers with UCST capability based on acrylamide and vinyl acetate were synthesized. These copolymers were synthesized in different percentages of acrylamide by free radical polymerization in solution conditions. All polymers compounds were characterized by H-NMR, FT-IR, DSC and GPC measurements. The...
Developing IP Camera-Based Edge Processing Architecture for Smart Building
, M.Sc. Thesis Sharif University of Technology ; Moeini Aghtaie, Moein (Supervisor) ; Rajabi Ghahnavieh, Abbas (Supervisor)
Abstract
Optimizing and reducing energy consumption will be a feature of smart cities in the future. In addition to the technical aspects of a technology, one of the most important obstacles to its lack of development is not considering economic factors. Investigating the economics and calculating the cost of using IoT systems in the energy sectors of a smart city is one of the most important issues. Using existing systems in buildings or adding limited and inexpensive hardware to make a building smart can make smartening a cost-effective operation and more widespread. In this research, a proposed architecture based on edge processing is described. In addition to receiving and displaying camera...
Numerical study of lorentz force interaction with micro structure in channel flow
, Article Energies ; Volume 14, Issue 14 , 2021 ; 19961073 (ISSN) ; Ali, K ; Ahmad, S ; Cai, J ; Sharif University of Technology
MDPI AG
2021
Abstract
The heat transfer Magnetohydrodynamics flows have been potentially used to enhance the thermal characteristics of several systems such as heat exchangers, electromagnetic casting, adjusting blood flow, X-rays, magnetic drug treatment, cooling of nuclear reactors, and magnetic devices for cell separation. Our concern in this article is to numerically investigate the flow of an incompressible Magnetohydrodynamics micropolar fluid with heat transportation through a channel having porous walls. By employing the suitable dimensionless coordinates, the flow model equations are converted into a nonlinear system of dimensionless ordinary differential equations, which are then numerically treated for...
A numerical approach for analyzing the electromagnetohydrodynamic flow through a rotating microchannel
, Article Arabian Journal for Science and Engineering ; Volume 48, Issue 3 , 2023 , Pages 3765-3781 ; 2193567X (ISSN) ; Ahmad, A ; Ahmad, S ; Ahmad, S ; Jamshed, W ; Sharif University of Technology
Institute for Ionics
2023
Abstract
The purpose of the paper is to develop a mathematical foundation for exploring the complex interaction of Coriolis and Lorentz forces with the electromagnetohydrodynamic (EMHD) flow of a power-law fluid inside a microchannel with wall slip condition. Both the Lorentz and Coriolis forces act orthogonally to each other. Mathematical modeling of the problem is based on a set of classical Maxwell and Navier–Stokes equations, which are subsequently solved numerically by employing an implicit finite difference methodology. The numerical solution thus obtained has been found to be in an excellent agreement correlation with the ones reported in the scientific literature, for some limiting cases. A...
A self-similar approach to study nanofluid flow driven by a stretching curved sheet
, Article Symmetry ; Volume 14, Issue 10 , 2022 ; 20738994 (ISSN) ; Jamshed, W ; Ahmad, S ; Bashir, H ; Ahmad, S ; Tag El Din, E.S.M ; Sharif University of Technology
MDPI
2022
Abstract
Nano-fluids have considerable importance in the field of thermal development that relates to several industrial systems. There are some key applications in recent construction systems flow, as well as microscale cooling gadgets and microstructure electric gadgets for thermal migration. The current investigation concludes the study of electrically conducting nano-fluid flow and heat transfer analysis in two-dimensional boundary layer flow over a curved extending surface in the coexisting of magnetic field, heat generation and thermal radiation. The small sized particles of copper (Cu) are taken as nanoparticles and water is assumed to be the base fluid. We used quasi-linearization and central...
Thin Film Thickness Measurement Using Colors of Interference Fringes
, M.Sc. Thesis Sharif University of Technology ; Amjadi, Ahmad (Supervisor)
Abstract
There are several methods for measuring thin film thickness, however, for the analysis of liquid film motors [1] we need a method which is capable of measuring the thickness using a single image of the film. In this work, we use the colors that appear on thin films, such as soup bubbles, which is a result of light interference to calculate the thickness of the layer
Thermal Relaxation Time Of Healthy and Cancerous Tissue In Pulsed Laser Using Monte Carlo Simulation
, M.Sc. Thesis Sharif University of Technology ; Amjadi, Ahmad (Supervisor)
Abstract
Thermal relaxation time is the time when maximum temperature of a particle get to 1/e of it’s initial value. The destruction of a tissue depends to this important parameter. This parameter has studied by Monte Carlo simulation of pulsed laser in to environment as healthy and cancerous tissue. The main goal of this method is providing proper temperature in a special area so that minimize thermal destruction around that area. In this thesis, temperature distribution of tissue that is caused by pulsed laser, has solved by new method;in this new method the pulse duration uses for Monte Carlo simulation. Also using the solution of radiation transfer equation by Discretes Ordinate Method, new...
Effect of Amplitude of Electric Field on the Rotation of Liquid Film
, M.Sc. Thesis Sharif University of Technology ; Amjadi, Ahmad (Supervisor)
Abstract
By direct and alternating electric field applied to thin film of liquid suspended in the air we can spin out and control it. Rotation pattern depends on the geometry of the electrodes and the applied magnetic field. This is called a rotating liquid film (Liquid Film Motor). To determine the cause of rotation, different models have been proposed. In this project we have tried to check the accuracy of any of the models. Using particle velocimetry using the photo, we calculate the velocity pattern. Then, using the Navier-Stokes equation calculate the acceleration and viscosity from the velocity. Then, for a special arrangement using a finite diffrent method, electric potential and the electric...
Design and Build an Acoustic Tweezers and Move up the Polystyrene Particles
, M.Sc. Thesis Sharif University of Technology ; Amjadi, Ahmad (Supervisor)
Abstract
Ultrasound waves have attracted substantial attention due to their potential for trapping the small particles, which cannot be handled by usual tweezers. The acoustic tweezer is a technology that is able to tarp and control the movement of micrometer to millimeter objects by standing or focused sound waves. Acoustic tweezers are the subject of many researches around the world, due to simplicity, cost-effective, biocompatibility and most important better performance in non-transparent optical environments, compared with optical tweezers.In this project, by using a ring piezoelectric and a power amplifier, an acoustic tweezer was designed and constructed. Moreover, the polystyrene particles...
Prediction of Agricultural Water Demand and Uncertainties Under Climate Change(Case Study: Wheat in Cities of Dezful and Andimeshk)
, M.Sc. Thesis Sharif University of Technology ; Abrishamchi, Ahmad (Supervisor)
Abstract
Climate change impacts especially on temperature and precipitation, may have various effects on agriculture and water demand of agriculture sector in different regions around the world. Based on numerous researches, these effects may be positive in a region while another region might endure negative effects. Therefore carrying out researches and developing methods to predict these impacts as well as mitigating strategies seem to be essential. The most worldwide accepted method is using global circulation models (GCMs) outputs under different greenhouse gases emission scenarios, and according to Intergovernmental Panel on Climate Change (IPCC) assessments. IPCC claims that the most recent...
Assessing the Ecological Potential of Tehran City Using Sustainable Urban Criteria
, M.Sc. Thesis Sharif University of Technology ; Abrishamchi, Ahmad (Supervisor)
Abstract
The citizens’ dissatisfaction with the decreased life and residential care quality is increasing as a result of the rapid growth and development of cities. To find an effective solution to reduce and control these harmful effects is one of the main concerns of urban managers and planners in most countries. In this research, various ecological and sustainability criteria were selected through library-based studies and relative recognition of the region. The Maps were mostly provided through satellite imagery and some by using synoptic data collected from the official aerology website of the country, Iran. Through surveying the experts, different criteria were evaluated and based on the...
A case study of different magnetic strength fields and thermal energy effects in vortex generation of Ag-TiO2 hybrid nanofluid flow
, Article Case Studies in Thermal Engineering ; Volume 47 , 2023 ; 2214157X (ISSN) ; Ali, K ; Ahmad, S ; Ahmad, S ; Jamshed, W ; Raizah, Z ; El Din, S. M ; Sharif University of Technology
Elsevier Ltd
2023
Abstract
Vortices grab the attention of many scientists while analyzing any flow model due to their importance in interpreting fluid mixing and mass transport phenomena. Since vortices exist in the natural environment, so researchers need to investigate them whenever they are encountered. Solar collectors, automobile cooling, engine applications, thermal management, and machine cutting, are just a few of the major areas in which most hybrid nanofluids could help to improve overall performance. The goal of this study is to demonstrate the highly complex dynamics of a Lorentz force, which governs the rotation of nanoparticles and the composition of the complex configuration of eddies inside the fluid...