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    Exchange Flow Through Emergent Non-homogenous Canopy

    , M.Sc. Thesis Sharif University of Technology Rahnamyie Zekavat, Payam (Author) ; Jamali, Mirmosadegh (Supervisor)
    Abstract
    Numerical and laboratory models were used to investigate gravity exchange flow caused by spatial heterogeneity in water temperature, through emergent vegetation with varying diameter along their height (denoted by the parameter ) causing varying stem frontal area along vertical axis. Numerical model was used to anticipate flow characteristics and their alterations relative to non-dimensional vegetation diameter ratio. A set of Teflon dowels with various heights was used to simulate considered vegetative cross-section changes along vertical axis. Interface profile, toe velocity and flow rate were studied. Interface height and flow rate were inquired near the gate where expected to be... 

    Analysis and Study the Effect of Knowledge Management Implementation on Productivity Case Study: Tehran Regional Electric Company

    , M.Sc. Thesis Sharif University of Technology Payam Asgari, Mahboubeh (Author) ; 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 Nik Payam, Hossein (Author) ; 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) Payam, A. F ; 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... 

    Kinematic analysis of dynamic lumbar motion in patients with lumbar segmental instability using digital videofluoroscopy

    , Article European Spine Journal ; Volume 18, Issue 11 , 2009 , Pages 1677-1685 ; 09406719 (ISSN) Ahmadi, A ; Maroufi, N ; Behtash, H ; Zekavat, H ; Parnianpour, M ; Sharif University of Technology
    2009
    Abstract
    The study design is a prospective, case-control. The aim of this study was to develop a reliable measurement technique for the assessment of lumbar spine kinematics using digital video fluoroscopy in a group of patients with low back pain (LBP) and a control group. Lumbar segmental instability (LSI) is one subgroup of nonspecific LBP the diagnosis of which has not been clarified. The diagnosis of LSI has traditionally relied on the use of lateral functional (flexion-extension) radiographs but use of this method has proven unsatisfactory. Fifteen patients with chronic low back pain suspected to have LSI and 15 matched healthy subjects were recruited. Pulsed digital videofluoroscopy was used... 

    Principal component analysis-ranking as a variable selection method for the simulation of 13C nuclear magnetic resonance spectra of xanthones using artificial neural networks

    , Article QSAR and Combinatorial Science ; Volume 26, Issue 6 , 2007 , Pages 764-772 ; 1611020X (ISSN) Jalali Heravi, M ; Shahbazikhah, P ; Zekavat, B ; Ardejani, M. S ; Sharif University of Technology
    2007
    Abstract
    A Quantitative Structure-Property Relationship (QSPR) relating atom-based calculated descriptors to 13C NMR chemical shifts was developed to accurately simulate 13C NMR spectra of polyhydroxy and methoxy substituted dibenzo pyrons (xanthones). A dataset consisting of 35 xanthones was employed for the present analysis. A set of 132 topological, geometrical, and electronic descriptors representing various structural characteristics was calculated for each of 497 unique carbon atoms in the dataset. Principal Component Analysis (PCA)-ranking and Artificial Neural Networks (ANNs) were used as descriptor selection and model building methods, respectively. Analyses of the results revealed a... 

    Alginate/PVP/Pomegranate Seed Hydrogels as Bio-sorbents of Water Pollutants

    , M.Sc. Thesis Sharif University of Technology Hashemzadeh, Payam (Author) ; 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 Khalili, Mohammad Reza (Author) ; 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... 

    Iran’s oil development scenarios by 2025 [electronic resource]

    , Article Energy Policy ; Volume 56, May 2013, Pages 612-622 Abbaszadeh, Payam ; Sharif University of Technology

    Dynamic Simulation and Control of Reactive Systems Involving Metabolic Pathways

    , M.Sc. Thesis Sharif University of Technology Aghaee Foroushani, Mohammad (Author) ; 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... 

    Application of nanostructured aluminium titanate (Al2TiO5) photocatalyst for removal of organic pollutants from water: Influencing factors and kinetic study

    , Article Materials Chemistry and Physics ; Volume 256 , 2020 Azarniya, A ; Soltaninejad, M ; Zekavat, M ; Bakhshandeh, F ; Madaah Hosseini, H. R ; Amutha, C ; Ramakrishna, S ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    In this study, aluminum titanate (Al2TiO5)-based nanostructure with the outstanding photocatalytic performance was prepared via the simple citrate sol-gel method. The effects of thee operational variables such as pH, temperature, catalyst dosage, and initial dye concentration on the photodegradation efficiency of methylene blue (MB) were explored in some details. The results showed that compared to TiO2, AT benefits a superior photocatalytic activity due to its narrow band gap (2.88 eV) and low recombination rate of charge carriers. Increasing the wastewater temperature from 25 to 60 °C can improve the degradation percent from 22.15 to 52%. Based on the thermokinetic calculations, the...