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kehtari--payam
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Development of an Integrated Hybrid Model of Human Cardiovascular and Respiratory System for Control Study purposes
, M.Sc. Thesis Sharif University of Technology ; Bozorgmehri, Ramin (Supervisor)
Abstract
Mathematical models are used for describing physical systems to make it possible to study and investigate the behavior of these systems and compare their performance and improve them. For this reason, a mathematical model for cardiovascular system and respiratory system is used to study how these two systems interact. The cardiovascular system model and the respiratory system model comprise four and two compartments, respectively. In fact, the combined model contains the left and right ventricles, body tissue, lung, systemic blood circulation, and pulmonary compartments. Heart rate and alveolar ventilation are assumed to be the quantities through them the central nervous system controls the...
Analysis and Study the Effect of Knowledge Management Implementation on Productivity Case Study: Tehran Regional Electric Company
, M.Sc. Thesis Sharif University of Technology ; Mostafavi, Mostafa (Supervisor)
Abstract
The successful development and implementation of a knowledge management system requires principles and instructions compatible with the organization. In the absence of essential and domestic components of a given organization, the process of knowledge management implementation will fail to be successfully completed. There are now various models for the implementation of knowledge management; however, these models only recommend general strategic guidelines, hardly offering any specific strategic plans as to how organizations can successfully and effectively implement knowledge management. Since the promotion of productivity is the ultimate goal of knowledge management, the present research...
Coordinated Scheduling of Power and Natural Gas Systems Considering Demand Uncertainty
, M.Sc. Thesis Sharif University of Technology ; Rafiee, Majid (Supervisor)
Abstract
The everyday increasing electricity consumption of household and industrial sectors across the world, and also the limited generation capacity and fuel supplies has led electricity companies, whether in private or government sectors, to focus deliberately on power generation planning, its costs, risks and constraints Because of many reasons including high efficiency, low cost of capital investment, expeditious permitting, and operation flexibility of gas-fired generating units, electricity companies prefer them to old ones like coal-fired or oil-fired generating units. Thus natural gas has gained a significant share in the portfolio of electricity generation fuel resources, and it is...
Robust DTC control of doubly-Fed induction machines based on input-output feedback linearization using recurrent neural networks
, Article Journal of Power Electronics ; Volume 11, Issue 5 , 2011 , Pages 719-725 ; 15982092 (ISSN) ; Hashemnia, M. N ; Faiz, J ; Sharif University of Technology
2011
Abstract
This paper describes a novel Direct Torque Control (DTC) method for adjustable speed Doubly-Fed Induction Machine (DFIM) drives which is supplied by a two-level Space Vector Modulation (SVM) voltage source inverter (DTC-SVM) in the rotor circuit. The inverter reference voltage vector is obtained by using input-output feedback linearization control and a DFIM model in the stator a-b axes reference frame with stator currents and rotor fluxes as state variables. Moreover, to make this nonlinear controller stable and robust to most varying electrical parameter uncertainties, a two layer recurrent Artificial Neural Network (ANN) is used to estimate a certain function which shows the machine...
Alginate/PVP/Pomegranate Seed Hydrogels as Bio-sorbents of Water Pollutants
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor) ; Mollaabasi, Payam (Co-Supervisor)
Abstract
In the past decades, hydrogels have been used as an adsorbent with high potential to remove pollutants in water. Hydrogels are three-dimensional polymer networks that have the ability to absorb and store water and water-soluble compounds due to the presence of hydrophilic functional groups in their structure. Different particles with unique characteristics can be used to increase the efficiency of hydrogel absorption. Based on the type of pollutant, hydrogels are divided into three different forms, including particles, films and nanocomposites. In this research, the absorption effect of metal cations as well as the absorption kinetics of polyvinyl pyrrolidine-based hydrogels, sodium...
The Effect of Olive Leaf Green Inhibitor on the Corrosion Resistance of Steel Reinforcement in Geopolymer Concrete Pore Solution
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdollah (Supervisor) ; Hosseini, Payam (Co-Supervisor)
Abstract
In this research project, the aim was to investigate the potential of olive leaf extract as an eco-friendly inhibitor for enhancing the corrosion resistance of reinforcing steel in simulated geopolymer concrete pore solution (GCP) containing chloride ions. The inhibitory effects of olive leaf extract were evaluated using various electrochemical techniques as well as scanning electron microscopy. The main phenolic compounds present in olive leaf extract were identified using high performance liquid chromatography (HPLC). Moreover, the elements and chemical bonds present in the surface passive film of the steel bar immersed in the olive leaf inhibiting system were characterized using...
Enhance the Chlorine Resistance of Reverse Osmosis Membrane
, M.Sc. Thesis Sharif University of Technology ; Mousavi, Abbas (Supervisor) ; Abdekhodaei, Mohammad Jafar (Supervisor)
Abstract
Reverse osmosis membrane one of the common methods used for water desalination, today membrane, thin film composite(TFC) include three layers, top the these layers named selection layer, this poly amid layer contacted with feed water, sensitivity to chlorine in polyamide layer lead to high membrane chlorine sensitive. Difference methods used for enhance the chlorine resistance in polyamide membrane that categorized in three general categories, covering and protection of sensitive areas method has best results in comparison to other methods. In this research protection method choose and used, material that used, sanitized by result from surface analysis of commercial membrane manufactured in...
Iran’s oil development scenarios by 2025 [electronic resource]
, Article Energy Policy ; Volume 56, May 2013, Pages 612-622 ; Sharif University of TechnologyDynamic Simulation and Control of Reactive Systems Involving Metabolic Pathways
, M.Sc. Thesis Sharif University of Technology ; Bozorgmehry Bozarjomehry, Ramin (Supervisor) ; Setoodeh, Payam (Co-Supervisor)
Abstract
In this project, modeling, simulation, and control of the Saccharomyces Cerevisiae were studied. In the first section, simulation and control of a structural model of saccharomyces Cerevisiae were performed. Fuzzy Logic Controller (FLC) as a model-independent controller and Global Linearization Controller (GLC) as a model-based controller were designed. Additionally, two types of Kalman filters were designed to predict all states of the structural model: 1-Extended Kalman Filter (EKF), 2- Unscented Kalman Filter (UKF). As a concise explanation, the control action of the GLC is a function of all states of the model, and since that measuring all metabolites is not practical, the EKF and UKF...
Natural compounds for skin tissue engineering by electrospinning of nylon-Beta vulgaris
, Article ASAIO Journal ; Volume 64, Issue 2 , 2018 , Pages 261-269 ; 10582916 (ISSN) ; Mahmoudifard, M ; Kehtari, M ; Babaie, A ; Hamedi, S ; Mirzaei, S ; Soleimani, M ; Hosseinzadeh, S ; Sharif University of Technology
Lippincott Williams and Wilkins
2018
Abstract
Natural compounds containing polysaccharide ingredients have been employed as candidates for treatment of skin tissue. Herein, for the first time, electrospinning setup was proposed to fabricate an efficient composite nanofibrous structure of Beta vulgaris (obtained from Beet [Chenopodiaceae or Amaranthaceae]) belonged to polysaccharides and an elastic polymer named nylon 66 for skin tissue engineering. Both prepared scaffolds including noncomposite and composite types were studied by Scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, mechanical assay, and contact angle. Scanning electron microscope examinations have approved the uniform and homogeneous...
MgO-incorporated carbon nanotubes-reinforced Mg-based composites to improve mechanical, corrosion, and biological properties targeting biomedical applications
, Article Journal of Materials Research and Technology ; Volume 20 , 2022 , Pages 976-990 ; 22387854 (ISSN) ; Shamsipur, A ; Bakhsheshi-Rad, H. R ; Keshavarz, M ; Kehtari, M ; Ramakrishna, S ; Berto, F ; Sharif University of Technology
Elsevier Editora Ltda
2022
Abstract
In this study, magnesium oxide (MgO) nanoparticles are incorporated on carbon nanotubes (CNTs) to reinforce Mg-3Zn-1Mn alloy (ZM31 alloy) by semi-powder metallurgy, followed by hot extrusion, with the purpose of improving the mechanical and biological properties of Mg-based alloy. The microstructural analysis of the nanocomposites indicated a reduction in grain size of Mg alloy with the incorporation of CNTs with a maximum reduction of 61% (ZM31/CNTs), with further reduction in grain size (68%) detected when MgO integrated CNTs composites (ZM31/MgO-CNTs). The compression characteristics of the composites indicate an increase in ultimate compressive strength of 36% and 44%, respectively, with...
Microfluidic-based droplets for advanced regenerative medicine: current challenges and future trends
, Article Biosensors ; Volume 12, Issue 1 , 2022 ; 20796374 (ISSN) ; Heirani Tabasi, A ; Ghorbani, S ; Eyni, H ; Razavi Bazaz, S ; Khayati, M ; Gheidari, F ; Moradpour, K ; Kehtari, M ; Ahmadi Tafti, S.M ; Ahmadi Tafti, S. H ; Warkiani, M. E ; Sharif University of Technology
MDPI
2022
Abstract
Microfluidics is a promising approach for the facile and large-scale fabrication of monodispersed droplets for various applications in biomedicine. This technology has demonstrated great potential to address the limitations of regenerative medicine. Microfluidics provides safe, accurate, reliable, and cost-effective methods for encapsulating different stem cells, gametes, biomaterials, biomolecules, reagents, genes, and nanoparticles inside picoliter-sized droplets or droplet-derived microgels for different applications. Moreover, microenvironments made using such droplets can mimic niches of stem cells for cell therapy purposes, simulate native extracellular matrix (ECM) for tissue...