Search for: calculation
0.016 seconds
Total 377 records

    Theoretical Investigation of Ab-initio MD Approach to Increase the Efficiency and Accuracy of VCD Spectrum Calculation

    , M.Sc. Thesis Sharif University of Technology Hadi, Hossein (Author) ; Jamshidi, Zahra (Supervisor)
    Understanding of the Molecules is the main purpose of the chemistry. Ab-initio molecular dynamics (AIMD) as a branch of the computational chemistry, tries to give us a deep comprehension of the molecule, and its chemical, physical and optical activities. This comprehension, relies on the accuracy of quantum mechanics, in addition to the speed of the classical mechanics. The mixing of the quantum mechanics and the classical mechanics could simulate activities of the atoms in the time-domain, provided the mixing is done with precaution. This, in turn, helps us to forecast the response of a molecule in different situations, and also translating the macroscopic phenomena in a nanoscopic... 

    Theoretical Study of Solvent and Substituent Effects on Kinetic and Mechanism of Organic Reactions and Theoretical Study of Enzyme Reactions

    , Ph.D. Dissertation Sharif University of Technology Irani, Mehdi (Author) ; Gholami, Mohammad Reza (Supervisor)
    Computational chemistry is used to study solvent and substituent effects on kinetics and mechanism of some organic reactions. It also is used to study enzyme reactions and enzyme structures. Organic reactions were studied by ab initio quantum mechanics and Monte Carlo simulations. The enzyme studies were done by QM/MM and MD methods in Lund University. The studied organic reactions are 1) Reactions of hydroxylamine and aminoxide anion with methyl iodide. 2) Rearrangement of allyl p-tolyl ether. 3) Reactions of 1,4-Benzoquinone with Cyclopentadiene and Cyclohexadiene derivatives and reaction of cyclopentadiene and vinyl acetate. In the enzyme studies the catalytic reaction of Glyoxalase... 

    Structure and Conformational Study of Drug Compounds using NMR and Ab-initio Calculations

    , Ph.D. Dissertation Sharif University of Technology Chashmniam, Saeed (Author) ; Tafazzoli, Mohsen (Supervisor)
    NMR spectroscopy as a powerful technique is often used to investigate on structural and conformational studies on proteins and drug compounds. In this work, conformations and structural properties of drug compounds and some nucleoside derivations have been studied using advanced NMR techniques including H-H COSY, HMQC, HMBC and NOESY and quantum based calculations.Experimental analysis on Valsartan show that there are two simultaneous conformers (M and m) with unequal population in M-m type solvents and two stable conformers (N and n) in the N-n type solvents. As the results show, different intramolecular hydrogen bond is the reason for stability af all available conformers. In the... 

    The Management of Land-Based Pollution in Wetlands: A Case Study of Miankaleh Wetland

    , M.Sc. Thesis Sharif University of Technology Radseresht Hamedani, Mohammad (Author) ; Raie, Mohammad (Supervisor)
    Gorgan Bay and Miankaleh Wetland are considered as one of the biosphere reserves and among the areas of international importance in the Ramsar Convention, thus they have great importance. These two inseparable zones are located in the southeast of the Caspian Sea and are connected to the Caspian Sea through Chapaghli Canal and Ashuradeh Canal. The health and water quality of this area has undergone many changes over the years, and the re-reduction of its water level has caused concern among environmental activists. Since Miankaleh wetland is a shallow and semi-enclosed water area that is connected to the Caspian Sea through two narrow canals, pollutants that enter it from land will have a... 

    Calculating the Bandstructure of eSoM2-BN-Gr_h Heterostructure and Its Hopping Parameters for Tight Binding

    , M.Sc. Thesis Sharif University of Technology Karimizadeh, Mohammad Ali (Author) ; Rahim, Faez (Supervisor)
    The purpose of this research is to introduce a heterostructure for Vertical Tunneling Field-Effect Transitors, calculating its band structure and finding the tight binding hopping parameters of its structure. To do this, we must first study different kinds of heterostructures and choose the most suitable one among them. In this research, we selected the three-layer graphene eSoM2-BN-Gr_h for its high on/off current ratio (〖10〗^6). To find the band structure, first we should construct unit cell and then find its crystal structure after relaxation. The lattice constant for graphene and is the same, but the lattice constant of graphene andeSoM2-BN-Gr_h is different . The number of atoms in the... 

    Neutronics Calculations of Prismatic High-temperature Gas Cooled Reactor by Deterministic Method Using DONJON and DRAGON Codes and Comparison with Results of Probabilistic Methods (Monte Carlo).

    , M.Sc. Thesis Sharif University of Technology Mansouri Hassan Abadi, Javad (Author) ; Ghofrani, Mohammad Bagher (Supervisor)
    HTGRs are considered as 4th generation reactors which have prominent characteristics such as inherent safety, lower safety costs, High efficiency and high temperature applications. the most important challenges in developing these reactors is providing appropriate codes in design, simulating their performance and analysis of them. In this thesis, a japanese prismatic HTTR reactor has been selected as a reference reactor and the neurotic’s calculations implementation studied at cold zero power (CZP) and hot full power (HFP) states using DRAGON cell calculation codes and DONJON core computations. At CZP state, One group and two group radial & axial flux distribution, control rod critical... 

    Ab-initio Calculations of Electronic and Phonon Structures of Ba1-xKxFe2As2 (x = 0,0.5,1) Superconductor

    , M.Sc. Thesis Sharif University of Technology Sandoghchi, Mohammad (Author) ; Khosroabadi, Hossien (Supervisor) ; Akhavan Farshchi, Mohammad (Supervisor)
    After discovery of superconductivity in 1911 people try to find superconductors with higher Tc. High Tc superconductivity in cuprates and iron based superconductors was discovered in 1986 and 2008 respectively. However, there is not any unit theory for high Tc superconductivity in cuprates or iron based superconductors. Study of electronic and phonon structures of high Tc superconductor compounds can lead to find theory of high Tc superconductivity.
    In this dissertation electronic structure of Ba1-xKxFe2As2, which belongs to class of 122 of iron based superconductor, under potassium doping x=0,0.5,1 has been studied. To this end ab-initio method and Density functional theory have been... 

    Hypercomputation and Hypercomputer

    , M.Sc. Thesis Sharif University of Technology Ebrahimi Mood, Sepehr (Author) ; Ramezanian, Rasoul (Supervisor)
    Since the computation of human life is in progress rapidly, we need to offer new concepts in Computational Theory, to obviate these needs. One of these concepts are hypercomputation and hypercomputers, which draw lots of attention in recent years. In this thesis, we study hypercomputaion and hypercomputers in more details.First, we briefly review Computational Theory principles and hypercomputation. After that, we provide and explain about some hypercomputers models and their computational power. After a detail description of interactive computation, as one of the models of hypercomputation, we propose our “Consistent Persistent Turing Machine,” as a model of hypercomputer for interactive... 

    Design of a Barge Equipped with Turbojet for oil well Fire Extinguishing

    , M.Sc. Thesis Sharif University of Technology Heidari Aliabadi , Mojtaba (Author) ; Abbaspour Tehrani fard, Majid (Supervisor) ; Mehdigholi, Hamid (Supervisor)
    In this thesis, the use of jet-engine for oil well fire fighting which is a latest in kind is described and analyzed. For this purpose, more familiarization with this system and some knowledge’s such as hydrodynamics characteristic of nominated area, traditional ways of fire fighting in region, different types of jet engines available type of offshore vessels, type of flame and their characteristic are required, which after studying and analyzing above fields in details, the use of turbojet motors and barge has been chosen for the case to obtain optimum specification os this turbojet motors and required dimensions of barge Some information about oil well shuch as, fluid output, speed rate... 

    Design of a Novel Gait Analysis System Using Kinect Sensor for Rehabilitation Applications

    , M.Sc. Thesis Sharif University of Technology Bilesan, Alireza (Author) ; Behzadipour, Saeed (Supervisor)
    To date various commercial systems were used in the gait analysis area. These systems have some difficulties for clinical use, such as being indwell, making trouble in movement and high prices. The Kinect sensor does not have problems of these systems. If the error of sensor is acceptable, Kinect sensor is a suitable choice for application in clinics. The possibility of utilization of the Kinect sensor as a gait analysis system has been studied in this research. The sensor errors in calculation of gait parameters for lower limb joints angle were computed. In previous researches the Kinect sensor error has been calculated for upper limb joints angle and the subject was standing motionless in... 

    Simulation & Design of a Gamma Scanner System for Radioactive Waste Drums with Low and Intermediate Level Activity

    , M.Sc. Thesis Sharif University of Technology Bagheri, Hamed (Author) ; Samadfam, Mohammad (Supervisor)
    In this thesis, a Segmented Gama Scanning System for measuring total activity of the low/intermediate level radioactive waste drums is designed and a prototype 3-segmented commercial system is manufactured by using NaI detectors. The optimum distance of detector from drum surface and the optimum number of detectors on reconstruction of the radioactivity of the waste drum were studied by MCNP simulations. In addition, the effects of inhomogeneous distribution of radioactivity, the addition of lead filters to detectors, the change in collimator length and the asymmetrical placement of a drum on the rotary plate were also examined by the MCNP calculations. In the absence of a real radioactive... 

    Design and Fabrication of Microfluidic System to Produce Microgel for Drug Delivery Application

    , M.Sc. Thesis Sharif University of Technology Shieh, Hamed (Author) ; Bastani, Dariush (Supervisor) ; Saadatmand, Maryam (Supervisor) ; Eskandari, Mahnaz (Supervisor)
    Due to the increasing need of use of drugs and insufficient efficiency of conventional methods, drug delivery systems has gathered a lot of interests. There are different systems existing for controlled drug delivery, among which is implementation of hydrogel microparticles (microgels) as carriers with high potential. The most important factor in these systems is size distribution of drug-carrying microgels and a narrow size distribution leads to a controlled and suitable release. Due to unique characteristics of microfluidic systems, significant focus has been placed on them nowadays for production of microgels with suitable morphology and narrow size distribution. Therefore, in this study... 

    Design and Fabrication of a Balance Training Apparatus

    , M.Sc. Thesis Sharif University of Technology Behjat, Amir (Author) ; Behzadipour, Saeed (Supervisor) ; Farahmand, Farzam (Co-Advisor)
    One of the main reasons of being unable in doing routine jobs is the disability to attain and keep balance. This ability can be restored using rehabilitation techniques. A physiotherapist can be very helpful. This approach, however, apart from being very time consuming and expensive, needs quite a few physiotherapists. The physiotherapist will be prone to physical damages as well. This leads to improving therapy methods which do not require a physiotherapist. Using the rehabilitation balance devices can help solve the problem to some extents. If good device with reliable value system be developed, this device can be used without physiotherapist.
    This project has been carried out to... 

    2D Compositional Simulation of Reservoirs using Finite Volume Method

    , M.Sc. Thesis Sharif University of Technology Abdollahzadeh, Soleiman (Author) ; Pishvaie, Mahmoud Reza (Supervisor) ; Fatemi, Mobin (Supervisor)
    One of the main purposes of this project is to propose an efficient and stable algorithm of a semi-discretized formulation for compositional simulation of oil reservoirs. In this algorithm, all the equations including both mass balances and equilibrium equations are solved simultaneously. The gradient terms are discretized by the Finite Volume Method (FVM). The resulting Differential Algebraic Equation, the so-called DAE, are solved by MATLAB functions. Another novel technique developed, handles each block equations set, separately. In this block-by-block scheme, there are two set of equations; the primary (mass balance) and secondary (equilibrium) equations. In the primary ones, the... 

    Neutronic Simulation of Generation IV Prismatic High Temperature Reactors and Noise Analysis

    , Ph.D. Dissertation Sharif University of Technology Torabi Ardekani, Abbas (Author) ; Ghofrani, Mohammad Bagher (Supervisor)
    This thesis has been done with the goal of comprehensive neutronic calculation of a small size High Temperature Gas Cooled Reactor and HTTR was selected as a reference reactor for simulations. Calculations are divided into four parts of zero and full power stochastic calculations, deterministic calculations and noise analysis. In zero power calculations, an algorithm is proposed for modeling random arrangement of TRISO particles in the fuel compacts of HTTR. The effect of this arrangement on criticality calculations, i.e. effective multiplication factor and critical position of control rods, is then compared with regular arrangement. In the second part, full power calculations with the use... 

    Simulation of Kick Control Process During Drilling with Assumption of Two-phase Flow

    , M.Sc. Thesis Sharif University of Technology Jahanpeima, Yaser (Author) ; Jamshidi, Saeed (Supervisor)
    During the drilling of oil and gas wells, the probability of a kick resulting in blow out is high. In the event of a kick, well should be controlled immediately and prevented blowing out. Common methods include: driller method, wait and weight method and concurrent method. In this project, simulation of well control process is done for common well control methods, for water based muds and oil based muds. Movement of different fluids, their combination and removal of fluid from the well are simulated and the results are listed. The flash calculations are done for oil based mud and dissolution of kick fluid in the oil based mud is considered. After simulating and calculating necessary... 

    Simulation of Active Proton Therapy Scanning System with GATE Simulator in Order to Reduce the Dose Reached to the Patient

    , M.Sc. Thesis Sharif University of Technology Asadi, Ali (Author) ; Hosseini, Abolfazl (Supervisor) ; Vosoughi, Naser (Supervisor)
    Validation of dosimetry accuracy in the context of advanced methods for radiotherapy, including proton therapy for ensure the accuracy of treatment plan is nessecory. One of the reasons for using MC code is the modeling of PT systems and the support of more accurate computation of dose distribution in clinical tarin. The purpose of this project is to validate the modeling of a spot scanning proton therapy system using a GATE MC code. In this study, the dose distribution calculated in the calibration process of the device and syno TPS is used as a criterion and the dose distribution obtained from the GATE MC code is calculated and validated with it. For this purpose, a water phantom was used... 

    Simulation of GTL Process Slurry Bubble Column Reactor Using CFD Methods

    , Ph.D. Dissertation Sharif University of Technology Irani, Mohammad (Author) ; Bozorgmehri, Ramin (Supervisor) ; Pishvaie, Mahmoud Reza (Supervisor) ; Tavassoli, Ahmad (Co-Advisor)
    In this thesis non-ideal behavior of fluids and its effects on hydrodynamic and mass transfer in multiphase flow is studied. A numerical framework has been proposed to model the interacting effects of mixture non-ideality and mass transfer on hydrodynamics of a multiphase system using CFD methods. Using the numerical framework mass and momentum transfer in a system was simulated. The system consists of a cylindrical vessel filled with vapor and liquid hydrocarbons which selected as the benchmark. The liquid hydrocarbon is chosen to be pure Octane and the hydrocarbon in the gas phase is assumed to be Propane. Due to operating condition (T=323 K, P =445 kpa) the behavior of fluid is non-ideal... 

    Coarse Grain Molecular Dynamics Simulation of Drug Carrier Translocation into Cell Membrane

    , M.Sc. Thesis Sharif University of Technology Damirchi, Behzad (Author) ; Saidi, Mohammad Said (Supervisor) ; Firoozabadi, Bahar (Supervisor)
    With the increasing development of the pharmaceutical industry and producing drugs with specific performance, its transfer into cells is also very important. Cell membranes are effectively impermeable to hydrophilic compounds unless the permeation is facilitated by dedicated transport systems. This means that many hydrophilic compounds, including many promising drug candidates, fail to reach their intracellular target because they cannot spontaneously cross lipid membranes. As a consequence, there is much interest in finding ways to facilitate the transport of molecules across cell membranes. Cell-penetrating peptides (CPPs) in particular have shown much promise as potential delivery agents... 

    Dose Simulation in Different Body Parts in Radiotherapy Using Fluka Monte Carlo Code on Human Phantom and Benchmarking with TL Dosimetry

    , M.Sc. Thesis Sharif University of Technology Montazam, Mahnaz (Author) ; Sohrabpour, Mostafa (Supervisor) ; Mahdavi, Rabi (Supervisor)
    Radiation therapy is a treatment modality that is used in treatment of most newly diagnosed cancer patients. In this method the interaction of radiation with matter and their biological effects is used for cancer treatment. The energy and intensity of the radiation in radiotherapy should be considered in order to have a lethal effect on tumors. Linear accelerators are substitutes for previous methods of radiotherapy in all over the world. These machines can work in both electron and photon mode. The Monte Carlo technique has become ubiquitous in medical physics in the last 50 years. The range of applications is very broad in medical physics. The increased use of Monte Carlo techniques is...