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faramarzi--vahid
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Simulation of Graphene Nanoribbon based Photodetector
, M.Sc. Thesis Sharif University of Technology ; Faez, Rahim (Supervisor)
Abstract
In this work, we have simulated graphene nanoribbon based photodetector and impact of changing the width, and Boron-Nitride doping and Stone-Wales defects on the optical properties of GNR has study. The energy band structure of GNR with nearest-neighbor approximation in a tight binding model calculated. To correspond with experiment and accuracy, we need to consider the impact of third nearest neighbors and edge bond relaxation. By Using the band structure, we calculated joint density of state and optical matrix elements and obtain inter band selection rule for A-GNR and Z-GNR. Then, using the Fermi’s golden rule, we investigate optical properties of GNR such as optical conductivity and...
Theoretical Study of Metallochlorophylls of Forth Period Elements in Periodic Table
, M.Sc. Thesis Sharif University of Technology ; Parsafar, Gholamabbas (Supervisor)
Abstract
In this study, some properties of metallochlorophylls - compounds produced by replacing Mg2+ in tetrapyrrolic ring of chlorophyll b with divalent ions – of the forth period transit elements of the periodic table have been investigated. Using DFT/B3LYP method and DGDZVP basis set, structures of these compounds were optimized and the energy of electronic levels, Gibbs free energy of formation of complex, contribution of atomic orbitals to formation of molecular orbitals and partial charges in these molecules were computed. The results show that some properties of these complexes cannot be justified by the common theories of complexes. Among these properties is the negligible effect of...
Model Predictive Control Based on Hybrid Neural Networks of a Fedbatch Yeast Production Fermenter
, M.Sc. Thesis Sharif University of Technology ; Pishvaie, Mahmood Reza (Supervisor)
Abstract
Due to underlying dynamic factors, many bioprocesses operate in semi-batch or batch processes without fixed points of operation. As a result, linear model-based control is not straightforward for these processes. Additionally, optimal policy design and successful control of constrained systems depend on having an appropriate dynamic model within the process scope. In bioprocessing, synthesizing and controlling such dynamic models presents numerous challenges, as most relationships are quasi-monod and involve parameter estimation from nonlinear reactor data. One approach to addressing this issue is using black box models like neural networks. However, employing purely artificial neural...
Nanoribbons of SnO2 as a high performance Li-ion battery anode material
, Article Materials Research Express ; Volume 5, Issue 6 , 2018 ; 20531591 (ISSN) ; Abnavi, A ; Ghasemi, S ; Sanaee, Z ; Sharif University of Technology
Institute of Physics Publishing
2018
Abstract
Here, SnO2 nanoribbons (NRs) synthetized on the catalyst-free stainless steel (SS) substrate as a possible anode for Li-ion batteries (LIBs) have been reported. SnO2 NRs were synthesized on catalyst-free SS substrate via vapor-solid (VS) growth approach. Morphological and structural characterizations of the SnO2 NRs were confirmed using scanning electron microscopy (SEM), transmission electron microscopy (TEM) microscopes and x-ray diffraction (XRD) respectively. The prepared binder-free electrode demonstrated high initial discharge/charge capacities of 1818/929 mAh g-1 at current density of 300 mA g-1. A reversible capacity of 676 mAh g-1 with a coulombic efficiency of 98.5% has been...
Numerical simulation of unsteady airflow in a nasal cavity for various sizes of maxillary sinus opening in a virtual endoscopic surgery
, Article Respiratory Physiology and Neurobiology ; Volume 291 , 2021 ; 15699048 (ISSN) ; Amjadimanesh, H ; Faramarzi, M ; Sadrizadeh, S ; Abouali, O ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Functional endoscopic sinus surgery (FESS) is performed to treat sinusitis when treatment with medication fails. In the present study, three different virtual maxillary sinus endoscopic surgeries were performed on a realistic 3-D computational model of the nasal cavity of an adult male under the supervision of a specialist. They included only uncinectomy, uncinectomy + 8mm Middle Meatal Antrostomy (MMA) and uncinectomy + 18 mm MMA. Simulations were performed for two human activity respiratory rates, including rest and moderate activities, and effects of different surgeries and respiratory rates on maxillary sinus were investigated. It was found that after endoscopic sinus surgery, the volume...
SnO2@a-Si core-shell nanowires on free-standing CNT paper as a thin and flexible Li-ion battery anode with high areal capacity
, Article Nanotechnology ; Volume 28, Issue 25 , 2017 ; 09574484 (ISSN) ; Sadati Faramarzi, M ; Abdollahi, A ; Ramzani, R ; Ghasemi, S ; Sanaee, Z ; Sharif University of Technology
Institute of Physics Publishing
2017
Abstract
Here, we report 3D hierarchical SnO2 nanowire (NW) core-amorphous silicon shell on free-standing carbon nanotube paper (SnO2@a-Si/CNT paper) as an effective anode for flexible lithium-ion battery (LIB) application. This binder-free electrode exhibits a high initial discharge capacity of 3020 mAh g-1 with a large reversible charge capacity of 1250 mAh g-1 at a current density of 250 mA g-1. Compared to other SnO2 NW or its core-shell nanostructured anodes, the fabricated SnO2@a-Si/CNT structure demonstrates an outstanding performance with high mass loading (∼5.9 mg cm-2), high areal capacity (∼5.2 mAh cm-2), and large volumetric capacity (∼1750 mAh cm-3) after 25 cycles. Due to the...
Invetigation Over Bio Elimination of Para Chlorophenol by Paraconiothyrium Fungal Strain Variabile
, M.Sc. Thesis Sharif University of Technology ; Yaghmaei, Soheila (Supervisor) ; Faramarzi, Mohammad Ali (Supervisor)
Abstract
The ability of Paraconiothyrium variabile, a soil isolated ascomycete, was investigated to remove para chlorophenol in submerged culture media. Among the tested para chlorophenol concentrations, concentration of 40 and 100 mg l-1were found to have minimum and maximum toxic effects, respectively, on the growth of the microorganism and at the same time high and low bioelimination percentages. The fungal strain was able to remove 86% of ρ-CP (with initial concentration of 40 mg l-1) but no significance removal observed at 100 mg l-1 concentration. Monitoring of laccase production level in the fermentation broth together with pollutant removal confirmed the key role of this copper containing...
Removal of chlorophenolic derivatives by soil isolated ascomycete of Paraconiothyrium variabile and studying the role of its extracellular laccase
, Article Journal of Hazardous Materials ; Volume 209-210 , 2012 , Pages 199-203 ; 03043894 (ISSN) ; Movahednia, M. M ; Yaghmaei, S ; Tabatabaei Sameni, M ; Rastegar, H ; Sadighi, A ; Faramarzi, M. A ; Sharif University of Technology
2012
Abstract
The ability of Paraconiothyrium variabile, a laccase producing ascomycete recently isolated from soil, was studied to eliminate chlorophenol derivatives in submerged culture medium. Among the tested compounds, ρ-chlorophenol (ρ-CP) and pentachlorophenol (PCP) were found to have minimum and maximum toxic effects, respectively, on the growth of the microorganism and at the same time high and low bioelimination percentages. The fungal strain was able to remove 86% of ρ-CP (with initial concentration of 40mgl -1) and 56% of 2,4-dichlorophenol (2,4-DCP; with same concentration as ρ-CP) after 9 days of incubation while no elimination was observed in the presence of 2,4,6-trichlorophenol...
Synthesis and characterization of 1-amidino-O-alkylureas metal complexes as α- glucosidase Inhibitors: Structure-activity relationship, molecular docking, and kinetic studies
, Article Journal of Molecular Structure ; Volume 1250 , 2022 ; 00222860 (ISSN) ; Daneshfar, M ; Daneshfar, Z ; Iraji, A ; Samandari Najafabad, A ; Faramarzi, M. A ; Mahdavi, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In the present study, metal complexes of 1-amidino-O-alkylureas were designed, synthesized and characterized by elemental analyses, FT-IR spectra, XRD, Mass analyses and scanning electron microscopy (SEM). All synthesized complexes were screen as α-Glucosidase inhibitors. According to the in vitro results, the Cu (II) complexes showed superior potency compared to other tested metal complexes. Particularly, [Cu(L-Me)2](Cl)2 (1b) showed the strongest inhibition against α-Glucosidase with an IC50 value of 2.75 ± 0.3 µM which was comparable to that of acarbose (IC50 = 750 µM). These findings are supported by the ligands and enzyme interactions through molecular docking. © 2021 Elsevier B.V
Morphology of nanodroplets on structured surfaces
, Article Journal of Physics D: Applied Physics ; Volume 46, Issue 21 , May , 2013 ; 00223727 (ISSN) ; Moosavi, A ; Sharif University of Technology
2013
Abstract
We report different morphologies of nanodroplets over various topographical features of the supporting substrates. The effects of different parameters such as the profile of the disjoining pressure, droplet size and the geometrical parameters are studied and discussed. Also, the effects of a coating layer on the surface of the substrate are determined. It is demonstrated that the nanodroplets at some positions are not stable and gradually move to more stable positions so that the system has less energy. For grooves this results in a series of morphology diagrams of the nanodroplets over the grooves as a function of the grooves' width and the liquid volume
Study of the P-^ Effects on the Behavior of Split-Level Steel Structures
, M.Sc. Thesis Sharif University of Technology ; Khansari, Vahid (Supervisor)
Abstract
Due to unusual response of structures of buildings with irregularity in their architecture to dynamic excitations, to have a comprehensive knowledge of their behavior during earthquakes is of utmost importance. Building irregularities are in general divided into two major categories, namely Irregularity in Plane and Irregularity in Elevation, and one of the forms of the latter is where there is a split in the levels of the building. In this work, through a series of case studies, the effects of P- phenomenon on the behavior of steel split-level building structures were studied. 5, 10 and 15 story buildings with 5 and 6 bays, and level splitting of 30, 60, 90, 120 and 150 cm were studied. All...
Three Dimensional Simulation of Morphology of Nanodroplets Near and on Structured Substrates
, M.Sc. Thesis Sharif University of Technology ; Moosavi, Ali (Supervisor)
Abstract
Mesoscopic hydrodynamic equations are solved employing a VOF based method to investigate the equilibrium shape of nanodroplets positioned over various topographic geometries of the supporting substrate for three-dimensional systems. By taking into account liquid-liquid and liquid-solid interactions a complex distribution for inter-molecular forces over the substrates (the disjoining pressure) is observed. In this research we show that motion of nanodroplets not only caused by contact angle difference in drplets two sides, but also depend on disjoining pressure parameters.Geometries with increasing complexities, from wedges to three dimensional edges and wedges, were explored with the main...
Investigating the Seismic Behaviour of Split-Level Building Structures
, M.Sc. Thesis Sharif University of Technology ; Khonsari, Vahid (Supervisor)
Abstract
Observations made after previous earthquakes have shown the crucial role of irregularities in initiating damage in buildings with irregularity, either in Plan or in Elevation. Since in existing Building Codes, there is no provision for the distribution of the Equivalent Static Loads for such buildings, designers have no option but to resort to Dynamic Analysis. In this work, the seismic behaviour of a group of two-dimensional steel building structures with irregularity in elevation, namely Split-Level buildings, was studied. The studied structures consist of a series of 5- and 15-storey frames having two parts with splitting distance of 150 cm. Both, moment-resisting and braced frames were...
Use of Life Cycle Analysis to Compare Various Vehicle Technologies on Energy Consumption and External Cost for Semi-Public Applications: Case Study, City of Tehran
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Vahid (Supervisor)
Abstract
With the road transportation vehicles being widely used, concerns have been increased regarding their unwanted effects. Air pollution, climate change, and oil supply security are among these effects. Many alternative fuels and propulsion systems have been proposed to be used instead of conventional ICE vehicles in recent decades. This project intends to conduct a Techno-Economic comparison between different vehicle powertrains so as to select the suitable choice to substitute conventional ICE vehicles. The vehicle options are ICE vehicles using both gasoline and CNG as fuels, Hybrid Electric Vehicles (HEVs), Plug-in Hybrid Electric Vehicles (PHEVs), and Electric Vehicles (EVs). The amount of...
Numerical Study of Base Plates under Biaxial Bending
, M.Sc. Thesis Sharif University of Technology ; Khonsari, Vahid (Supervisor)
Abstract
Base plates as the connecting components of steel structures to their foundations, have a crucial role in the behavior of these structures. In order to limit the thickness of base plates hence their cost within reasonable values, various types of attachments (stiffeners) are normally added to them. In this project 6 different configurations, Models, for the base plate and its attachments were considered and studied through finite element analysis. Each Model was studied under the combination of biaxial moments and a range of compressive loads including 0, 0.05 P/Py, 0.10 P/Py and 0.15 P/Py, where Py is the plastic load of the column. The moment-rotation curves of all models under various...
Factorial Design of Experiments to Identify Effective Factors on Domestic Vehicle Emissions and Fuel Consumption
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Vahid (Supervisor)
Abstract
Reducing air pollutant emissions from vehicles is a difficult and time consuming procedure which needs utilizing of modern emission control equipment and setting strict regulations for car factories and drivers as well. How efficient these policies are and proposing operative solutions for air quality improvement depend on developing a sustainable model which is used in vehicle emission predictions and their share in total emissions. Emission factors are not constant values as they can be affected by various operational and ambient parameters. Development of Emission inventories calls for a huge number of measurements using different vehicles in diverse conditions. Thus, recognition of...
Micro-modeling of Tehran 4-stroke Gasoline Motorcycle Fleet Emission and Investigating the Effects of Increasing Fueling System and Engine Technology Level
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Vahid (Supervisor)
Abstract
The city of Tehran is dealing with air pollution problems for years. Providing a solution for this problem requires information about different pollutants emission sources. In this subjects, emission factors and emission models are essential tools for decision makers. Among different mobile emission sources in Tehran, motorcycles are of high importance. In this project, for the first time in Iran, exhaust gas pollutants emission of 66 motorcycles with different ages and engine displacement volumes were measured according to Euro-3 standard certification procedure. Measurement results showed that none of the tested motorcycles passed the Euro-3 certification limit on CO emission. Calculations...
Partially Homogenous HCCI Combustion Chemical Kinetics Model Initial Conditions Development by CFD Modeling
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Vahid (Supervisor)
Abstract
Homogeneous Charge Compression Ignition (HCCI) engines are the new generation of internal combustion engines which have diesel-like thermal efficiency, while they have low nitrogen oxide and soot emission. One of the major problems of HCCI engines is combustion timing control due to its dependence on reactivity of the charge and chemical kinetics. Moreover, limiting operation range between knock and misfiring is the other drawback of using these kind of engines. In the present work, partially homogeneous HCCI combustion in a single cylinder diesel engine is modeled using Computational Fluid Dynamics (CFD) coupled with chemical kinetics. Simulation includes the engine cycle from exhaust valve...
Traffic Source Particle Pollution Distribution Using Micro-scale Simulation
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Vahid (Supervisor)
Abstract
Today air pollution has become one of the major urban management concerns. Air pollution could have dangerous effects on human health in short time or long time in many situations. Numerical modelling is one of the most applicable among different ways for predicting pollutant concentration like field measurement, physical model in wind tunnel, and simulation. Modelling of pollutant dispersion is a way for estimating concentration and aggregation of the pollutant near the surface and with different distances from pollution source. In different dispersion models, one of simplest is the Gaussian model. In this approach it is supposed that emission plume obeys from Gaussian distribution and is...
Numerical Modeling of the Behavior of Base Plates with Various Degrees of Rigidity Under Cyclic Loads
, M.Sc. Thesis Sharif University of Technology ; Khonsari, Vahid (Co-Advisor)
Abstract
Due to the important role of base plates, both in transferring forces from the structure to the foundation, and also in transferring vibrations from soil to the structure, it is necessary to have sufficient knowledge on their behaviour and performance under monotonic and cyclic loading regimes. In fact, the behaviour of the supports of any structure cannot be identified without identifying the behaviour of its base plates. Numerous configurations with/without various types of attachments have been proposed and used for base plates. In this work, altogether six commonly-used types of base plates were studied and their behaviour under monotonic and cyclic loadings was obtained using commercial...