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shamkhali--amir-nasser
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Theoritical Investigation of Metallic Cations and Gas Adsorption on Surface of Carbon Nanostructures
, Ph.D. Dissertation Sharif University of Technology ; Tafazoli, Mohsen (Supervisor) ; Shamkhali, Amir Nasser (Supervisor)
Abstract
Carbon nanostructures are of great importance in scientific and industrial research. Two case of the important two-dimensional carbon nanostructures are graphitic carbon nitride (g-C3N4) and graphene. In the first part of this work, adsorption of important heavy metal cations including Hg+2, Ag+, Cr+3, Pb+2, Cu+2, Ni+2, Cd+2, Tl+, Sb+3, Zn+2 and As+3 on the surface of (g-C3N4) was investigated by density functional theory (DFT). The main purpose of this theoretical study is to evaluate the ability of g-C3N4 to adsorb pollutant cations. The most prominent result of this work was the ability of g-C3N4 for effective adsorption of As+3 and Sb+3 ions from aqeous solutions. Also, another...
Theoretical Investigation of Carbon Monoxide Adsorption on the Nickel Surface in the Macroscopic and Microscopic Scales
, Ph.D. Dissertation Sharif University of Technology ; Parsafar, Gholamabbas (Supervisor)
Abstract
In this work, CO interaction with macroscopic Ni(111) surface and microscopic Nin (n = 2-4) clusters were investigated. First, the CO interaction with various adsorption sites were studied by DFT methods on Ni(111) surface. On the basis of these calculations, hcp site has the strongest interaction with CO adsorbate. Then, the vibrational frequencies of C=O and adsorptive bond on the hcp site were calculated and the results show that anharmonicity of adsorptive bond is more important than C=O bond. Therefore, three potential models are considered for adsorptive bond and the effect of potential models on its thermodynamic properties was investigated. The results show that the effect of...
Investigation of Thermodynamic Relations in Microscopic Systems by Quantum Information Theory
, M.Sc. Thesis Sharif University of Technology ; Shafiee, Afshin (Supervisor) ; Shamkhali, Amir Naser (Supervisor)
Abstract
Entropy is one of the important quantities in thermodynamics. In this project has tried to make this quantity as a bridge between quantum and thermodynamics. Entropy has many definitions that the Shannon entropy is chosen in this work. By this definition of entropy, we are able to define the entropy for a electronic system in molecules. By this definition, we are seeking an answer for this question,”whether entropy has a similar application in quantum like thermodynamics or not?”. To elucidate this hypothesis, simple diatomic molecules are computed. In fact, displacement of the Shannon entropy has investigated in bond making process. The question is that whether we can use this quantity to...
Integrated Linear Programming Model for Airplane Landing Scheduling and Gate Assignment
, M.Sc. Thesis Sharif University of Technology ; Salmasi, Nasser (Supervisor)
Abstract
Airplane Landing Scheduling and Gate Assignment are two highly related problems in the literature. Although there is high relationship between these two problems, they have been studied independently from each other in the literature so far. This relation is due to that the input data of gate assignment problem is the output of airplane landing scheduling problem. In this study, an integrated linear programming model is proposed in order to improve the number of planes which are assigned to a jet-way by changing scheduling of their landing. Since this problem is NP-Hard, a meta-heuristic algorithm is based on tabu search (TS) is developed to solve this problem approximately. The proposed TS...
Hybrid control and motion planning of dynamical legged locomotion
, Book ; Sadati, Nasser
Wiley
2012
Abstract
This book provides a comprehensive presentation of issues and challenges faced by researchers and practicing engineers in motion planning and hybrid control of dynamical legged locomotion. The major features range from offline and online motion planning algorithms to generate desired feasible periodic walking and running motions and tow-level control schemes, including within-stride feedback laws, continuous time update laws and event-based update laws, to asymptotically stabilize the generated desired periodic orbits. This book describes the current state of the art and future directions across all domains of dynamical legged locomotion so that readers can extend proposed motion planning...
Presentation of a Model for Prediction of Ch4/Co2/H2s Permeation Through Polymeric Membranes
, M.Sc. Thesis Sharif University of Technology ; Mousavi, Abbas (Supervisor) ; Maghsoudi, Vida (Co-Advisor) ; Shamkhali, Amir Naser (Co-Advisor)
Abstract
Acidic gases separation from hydrocarbon mixtures is very important in natural gas industry. In this study, the separation of CO2 and H2S from CH4 investigates by experimental and molecular dynamics simulation approaches. For achievement to this goal, it is used two polymeric families, as be divided to polyurethanes and PEBAX copolymers. It is used 4 polyurethane membranes as are named PU-1, PU-2, PU-Ether, and PU-Ester from polyurethanes group. Also, it is applied 5 PEBAX commercial membranes have be known PEBAX-2533, PEBAX-4033, PEBAX-5533, PEBAX-4011, and PEBAX-1074. It is compared between simulation and experimental works and found that there is good agreement between...
Calculation of the Thermodynamical Properties of [BMIM][PF6] via Equation of State and Molecular Dynamic Simulations Data
, M.Sc. Thesis Sharif University of Technology ; Parsafar, Gholamabbas (Supervisor) ; Tafazzoli, Mohsen (Supervisor) ; Shamkhali, Amir Naser (Co-Advisor)
Abstract
In this thesis, We have investigated the accuracy of general equation of state ( EoS III ) and linear isotherm regularity ( EoS I ), introduced on 2009 and 1993, respectively, and the Ghatee’s equation of state ( EoS II ) introduced on 2001, for the pvT data and thermodynamic properties of [BMIM][PF6] ionic liquid. We have carried out simulations at first in a narrow range of pressure, namely within 1-3400 atm and in temperature range from 398 K to 1000 K. The results of fitting of EoS I, EoS II and EoS III into the simulations results, leads to R2 > 0.9936, 0.9800 and 0.9949 respectively, for the pressure range of 1-3400 atm and for the temperature range of 398-1000 K. The results of...
Corrosion Detection by Non-destructive Tests
, M.Sc. Thesis Sharif University of Technology ; Vosughi, Nasser (Supervisor) ; Movafeghi, Amir (Co-Advisor)
Abstract
Non-destructive Testing (NDT) methodsare among the most important ways that are used for inspection of industrial products. It can measure non-visible properties of material such as defect size and inclusions that is inside of the object.NDT is included several tests such as visual examination, eddy current testing, ultrasonic testing and radiographic testing.Radiography is one of the most common NDT methods that are used to detect the defects in objects by registering an image of the object on the radiography film. Corrosion is one of the most important defects in pipelines, where the most important concern is measuring the remaining thickness in corroded zone.
In this study, some...
In this study, some...
Effect of side by side interactions on the thermodynamic properties of adsorbed CO molecules on the Ni(111) surface: A cluster model study
, Article Molecular Physics ; Volume 108, Issue 10 , 2010 , Pages 1397-1412 ; 00268976 (ISSN) ; Parsafar, G ; Sharif University of Technology
2010
Abstract
The effect of electrostatic interactions on vibrational frequencies and thermodynamic properties of CO adsorbate on the Ni(111) surface is calculated by taking the first and second nearest-neighbour interactions into account. In order to obtain reasonable results, the cluster model of various surface adsorption sites with CO adsorbate is partially optimized, using Density Functional Theory and also the MP2 method for the hcp site. Comparison between DFT and MP2 results shows that DFT results are more reliable for this system. The stretching and bending frequencies of CO adsorbate are calculated using both Partial Hessian Analysis and Cluster-Adsorbate Coupling methods. Stretching and bending...
Effect of model potential of adsorptive bond on the thermodynamic properties of adsorbed CO molecules on Ni(111) surface
, Article Journal of Physical Chemistry B ; Volume 110, Issue 41 , 2006 , Pages 20435-20444 ; 15206106 (ISSN) ; Parsafar, G ; Sharif University of Technology
American Chemical Society
2006
Abstract
The effect of anharmonicity on the adsorption of CO molecules on the Ni(111) surface has been investigated. The DFT calculations are used to obtain the effective adsorption potential of the CO molecule on the Ni(111) surface. First, using an appropriate slab model, the geometry of adsorption system corresponding to hep, fcc, bridge, and on-top sites with p(2 × 2) arrangement and coverage of 0.25 ML is optimized by the DFT calculations using a plane wave basis set and ultrasoft pseudopotentials; this gives the hep site as the most stable site with De = 185 kJ/mol, for which the equilibrium distance of CO from the surface and C-O bond length on the surface are found to be 1.31 and 1.192 Å,...
Investigation of the Photonic Scattering Error in Radiography of Pipes and its Evaluation by Mote- carlo Simulation
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Nasser (Supervisor) ; Movafeghi, Amir (Co-Advisor) ; Kermani, Abotaleb (Co-Advisor)
Abstract
Non-destructive testing method is for detect specimen flaws such as (crack, porosity, impure, welding defects, corrosion etc.) without destruction the specimen under inspection. Particular characteristic of radiography is an image product from specimen inside under testing where help to identity and better comprehend at flaw nature. Photon scattering is one of important factor to reduce image quality and signal to noise ratio. Scattered photons can due toexistent ingredient in the radiography environment and curvature of material transmission pipe where cause the disorder creation in the radiography images. In this research, pipe radiography simulated using the TIC and TIR radiography...
Meta-Heuristic Algorithm for Minimization of Total Tardiness in Flexible Flow Shop Scheduling Problems
, M.Sc. Thesis Sharif University of Technology ; Salmasi, Nasser (Supervisor) ; Shavandi, Hassan (Co-Supervisor) ; Najafi, Amir Abbas (Co-Supervisor)
Abstract
This study deals with the heuristic solution of flexible flow shop scheduling problems with unrelated parallel machines. No preemption of jobs is allowed. As an objective function, this paper considers the minimization of total tardiness. As a first step to propose solution, two different mixed integer mathematical models are developed which tackle the problem at hand. The problem is NP-hard and thus the developed mathematical program can only solve problem instances for small sizes in a reasonable amount of time. The next step is to build heuristics which can provide feasible solutions in polynomial time for larger problem instances. Then in the study develops a constructive heuristic for...
Polar and low polar solvents media effect on dipole moments of some diazo Sudan dyes
, Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Vol. 127 , 2014 , Pages 340-348 ; ISSN: 13861425 ; Golghasemi Sorkhabi, Sh ; Shamkhali, A. N ; Sharif University of Technology
2014
Abstract
Absorption and fluorescence spectra of three Sudan dyes (Sudan III, SudanIV and Sudan black B) were recorded in various solvents with different polarity in the range of 300-800 nm, at room temperature. The solvatochromic method was used to investigate dipole moments of these dyes in ground and excited states, in different media. The solvatochromic behavior of these substances and their solvent-solute interactions were analyzed via solvent polarity parameters. Obtained results express the effects of solvation on tautomerism and molecular configuration (geometry) of Sudan dyes in solvent media with different polarity. Furthermore, analyze of solvent-solute interactions and value of ground and...
Simulation of Coolant Temperature Variation in VVER-1000 Reactor Using Temperature Noise Analysis
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Nasser (Supervisor)
Abstract
Temperature noise phenomenon in nuclear reactors results to the vital information about the system. This phenomenon may originate from coolant inlet temperature fluctuations, coolant fluid velocity fluctuations or the reactor power fluctuations in PWR reactors. Diagnosis of such temperature noise sources shall improve the reactor control and protection.The present research aims to develop a software to model the temperature noise in the axial direction of a single channel comprises of fuel rod and the associated coolant to recognize the type of temperature noise sources. In this regard, research stages are as follows: first the temperature noise caused by three conventional noise sources in...
Adaptive-Robust Control of Dynamic Systems Using Orthonormal Filters
, M.Sc. Thesis Sharif University of Technology ; sadati, Nasser (Supervisor)
Abstract
In this research, using orthonormal filters, an adaptive-robust controller is designed for a class of SISO dynamic systems for which the input and output datas are available. First, Laguerre filters are combined with orthonormal Chebyshev functions to increase the capability of Laguerre filters in identification of systems with unknown dynamics. Then, the resulted Lagueree-Chebyshev structure is used for closed loop identification of the system and controller is designed. Moreover, RBF neural networks are used to approximate some nonlinear terms appearing in the controller design process.
Finally, in order to minimize the control effort, a new approach is proposed that leads to a set...
Finally, in order to minimize the control effort, a new approach is proposed that leads to a set...
, M.Sc. Thesis Sharif University of Technology ; Vosoughi, Nasser (Supervisor)
Abstract
High purity Germanium (HPGe) detector is a sub branch of semiconductor detectors which has very good resolution, very little dead time, able tobuild in large dimensions and suitable for any condition that it is using in vast fields from space investigation to radiation therapy. this detector is usually used to detecting gamma radiations furthermore the best resolution can be attained with decreasing leakage current. for analyzing about operation of the HPGe detector, it needs to initiate a model of this detector. in this studing has been used modelGEM-15190,POP-TOP which is built by ortec company. for initiating, it was used liquid nitrogen and accessory equipments like high voltage supply,...
Olympic Games Scheduling
, M.Sc. Thesis Sharif University of Technology ; Salmasi, Nasser (Supervisor)
Abstract
In the present work, the problem of Olympic Games scheduling is investigated. Due to the high number of matches and limited number of resources, scheduling of the Olympic Games is a difficult and time consuming job. Also a balanced distribution of medals on the days of Olympic Games keep each day attractive for the people and prevent sudden changes in the medal ranking of countries. So, in regard to the limitations of the problem and to balance the distribution of medals, the Olympic Games are scheduled. In order to do that, at first, two mathematical models are presented. One of them is for obtaining the feasible and optimum solution in a specified period of time. The other model presents a...
Neutronic Simulation of Pebble Bed Reactors
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Nasser (Supervisor)
Abstract
The Very-High Temperature Reactor (VHTR) design is one of the six candidates for the Generation IV nuclear reactors. The reactor core type of the VHTR design is either prismatic or pebble-bed. In pebble bed reactors, the core is filled of thousands of graphite and fuel pebbles. Fuel pebbles in these reactors consist of TRISO particles, which are embedded in a graphite matrix stochastically. The reactor core is also stochastically filled up of fuel and dummy pebbles with an unequal ratio. These two stochastic geometries are the so-called double heterogeneous of this type of reactors. In the current study, a...
A Two Criteria Objective Function Flexible Flowshop Scheduling Problem With Machine Eligibility Constraint
, M.Sc. Thesis Sharif University of Technology ; Salmasi, Nasser (Supervisor)
Abstract
This study strives to minimize a two-criterion objective function of a flexible flow shop scheduling problem with receipt and delivery of jobs in groups and processing them individually. Every group of jobs has a release time, which means that all jobs are not available at the beginning of the planning horizon. Moreover, due to the special characteristics of every job in a group, only a subset of machines at each stage are eligible to process that job. This problem has many applications in production and service industries, such as restaurants and ceramic tile manufacturing companies. The objective function is determined based on the practical applications of the problem. It deals with...
Upper and Lower Bounding Methods for Flowshop and Flexible Flowshop Group Scheduling Problems
, Ph.D. Dissertation Sharif University of Technology ; Salmasi, Nasser (Supervisor)
Abstract
In this research sequence-dependent flowshop and flexible flowshop group scheduling problems are investigated. Several upper and lower bounding methods are proposed for the research problems. Permutation flowshop sequence-dependent group scheduling problem with minimization of total completion time is considered. Since the problem is shown to be strongly NP-hard, a Memetic algorithm (MA) is proposed. A lower bounding method base on the Branch-and-Price algrithm is also proposed. A statistical comparison shows that both the proposed MA and the proposed lower bounding method have better performance than the other methods from the literature with an average 5.96% percentage gap. Flexible...