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    Physical Modeling of Bioremediation of Gasoline Spill in the Vadose Zone

    , M.Sc. Thesis Sharif University of Technology Rahimi, Behnam (Author) ; Sadeghi, Hamed (Supervisor) ; Moghimi, Hamid (Co-Supervisor)
    Abstract
    Oil pollutants are among the important sources of pollution in countries with oil and gas industries such as Iran. Soil pollution by these pollutants is one of the environmental issues and hazards. All kinds of organic and inorganic pollutants in the soil may penetrate the underground water or enter the atmosphere in the form of gas, which respectively enters the food chain through absorption by plants or enter the body of living organisms through breathing. They include humans, which are a threat to the health and life of living beings. For example, many of these pollutions cause diseases such as cancer, suppression of the body's immune system, or even obesity; therefore, it is necessary to... 

    Innovative Financing Scheme for Repair and Rehabilitation of Critical Infrastructures Systems

    , M.Sc. Thesis Sharif University of Technology Moghimi, Nima (Author) ; Haj Kazem Kashani, Hamed (Supervisor)
    Abstract
    The aim of this research is to examine and propose solutions for financing projects aimed at reducing vulnerability in the oil industry's infrastructure against earthquakes and enhancing their seismic resilience. Design and construction issues, as well as the gradual deterioration of oil infrastructure, increase their vulnerability to earthquakes. Earthquakes can disrupt the proper and continuous functioning of these infrastructures by causing damage. Such disruptions or interruptions in the performance of oil industry infrastructure can have significant economic and social consequences. To mitigate these damages, investment in vulnerability reduction measures is essential. Financing... 

    Water electrolyte transport through corrugated carbon nanopores [electronic resource]

    , Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 90, Issue 1, July 2014, Article number 012304 Moghimi Kheirabadi . A ; Moosavi. A
    Abstract
    We investigate the effect of wall roughness on water electrolyte transport characteristics at different temperatures through carbon nanotubes by using nonequilibrium molecular dynamics simulations. Our results reveal that shearing stress and the nominal viscosity increase with ion concentration in corrugated carbon nanotubes (CNTs), in contrast to cases in smooth CNTs. Also, the temperature increase leads to the reduction of shearing stress and the nominal viscosity at moderate degrees of wall roughness. At high degrees of wall roughness, the temperature increase will enhance radial movements and increases resistance against fluid motion. As the fluid velocity increases, the particles do not... 

    An efficient tabu search algorithm for the single row facility location problem [electronic resource]

    , Article European Journal Of Operational Research ; Vol. 205, No. 1, pp. 98-105 Samarghandi, H. (Hamed) ; Eshghi, Kourosh ; Sharif University of Technology
    Abstract
    The general goal of the facility layout problem is to arrange a given number of facilities to minimize the total cost associated with the known or projected interactions between them. One of the special classes of the facility layout problem is the Single Row Facility Layout Problem (SRFLP), which consists of finding an optimal linear placement of rectangular facilities with varying dimensions on a straight line. This paper first presents and proves a theorem to find the optimal solution of a special case of SRFLP. The results obtained by this theorem prove to be very useful in reducing the computational efforts when a new algorithm based on tabu search for the SRFLP is proposed in this... 

    Sensitivity analysis of matching pennies game [electronic resource]

    , Article Mathematical and Computer Modelling ; Volume 51, Issues 5–6, March 2010, Pages 722–735 Yarmand, H. (Hamed) ; Eshghi, Kourosh ; Sharif University of Technology
    Abstract
    In this paper, we have discussed the results of sensitivity analysis in a payoff matrix of the Matching Pennies game. After representing the game as a LP model, the sensitivity analysis of the elements of the payoff matrix is presented. The game value and the optimal strategies for different values of parameters are determined and compared  

    Investigation of Io's auroral hiss emissions due to its motion in Jupiter's magnetosphere

    , Article Research in Astronomy and Astrophysics ; Volume 12, Issue 6 , 2012 , Pages 693-702 ; 16744527 (ISSN) Moghimi, M. H ; Sharif University of Technology
    2012
    Abstract
    The left-hand side of the auroral hiss emission observed by Galileo has a frequency time profile shaped very similar to the funnel shape observed in the Earth's auroral region. This close similarity indicates that we can use the theory of whistler-mode propagation near the resonance cone to locate the emission source. The general characteristics of the whistler mode are discussed. Then the position of the emission source is investigated using a geometrical method that takes into account the trajectory of Galileo. Initially a point source is assumed. Then the possibility of a sheet source aligned along the magnetic field lines which are tangent to the surface of Io is investigated. Both types... 

    Improvement of Software Quality Attributes based on the Properties of Relational and Non-relational data Models

    , M.Sc. Thesis Sharif University of Technology Moghimi, Hamed (Author) ; Habibi, Jafar (Supervisor)
    Abstract
    With the growing use of computer systems, especially in form of web applications, software development and customer requirements has become more complex. Modern computer systems are supposed to achieve non-functional requirements in addition to functional requirements. Non-functional requirements are also called software quality attributes. One of the most important quality attributes for today's software systems is performance. Today’s softwares due to the growing number of their users, need more efficiency than ever to properly meet the performance request.Storage components and databases are the most important factors in causing performance bottlenecks in web applications. Most of... 

    Critical Behavior of Neuronal Systems: an Information Theory Viewpoint

    , M.Sc. Thesis Sharif University of Technology Soltani, Miaad (Author) ; Moghimi, Saman (Supervisor)
    Abstract
    Experiments conducted in recent two decades indicated critical behavior in neural activity at different scales. Theoretically occurrences of these critical and power-law behavior can significantly facilitate brain activities correspondent to computation and memory tasks, but attaining the critical point essentially demands externally fine-tuning which has not been established yet. This fine-tuning often lies with placing system at transition point. Recent studies of group showed that a transition from synchronous to asynchronous phase could be achievable by a change in external parameters. At the very transition point, neuronal avalanches statistically demonstrate a power-law behavior which... 

    Water electrolyte transport through corrugated carbon nanopores

    , Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Vol. 90, issue. 1 , July , 2014 ; ISSN: 15393755 Moghimi Kheirabadi, A ; Moosavi, A ; Sharif University of Technology
    2014
    Abstract
    We investigate the effect of wall roughness on water electrolyte transport characteristics at different temperatures through carbon nanotubes by using nonequilibrium molecular dynamics simulations. Our results reveal that shearing stress and the nominal viscosity increase with ion concentration in corrugated carbon nanotubes (CNTs), in contrast to cases in smooth CNTs. Also, the temperature increase leads to the reduction of shearing stress and the nominal viscosity at moderate degrees of wall roughness. At high degrees of wall roughness, the temperature increase will enhance radial movements and increases resistance against fluid motion. As the fluid velocity increases, the particles do not... 

    Chaos in sandpile models

    , Article Modern Physics Letters B ; Volume 25, Issue 8 , 2011 , Pages 569-579 ; 02179849 (ISSN) Moghimi Araghi, S ; Mollabashi, A ; Sharif University of Technology
    2011
    Abstract
    We have investigated the "weak chaos" exponent to see if it can be considered as a classification parameter of different sandpile models. Our simulation results show that the (Abelian) BTW sandpile model, the (non-Abelian) Zhang model, and the ("Abelian") Manna model possesses different "weak chaos" exponents, so they may belong to different universality classes. Finally, we show that getting off the critical point destroys this behavior in these models  

    The effect of the number of dissipative sites on a sandpile model

    , Article Journal of Physics A: Mathematical and Theoretical ; Volume 48, Issue 8 , January , 2015 ; 17518113 (ISSN) Moghimi Araghi, S ; Sebtosheikh, M ; Sharif University of Technology
    Institute of Physics Publishing  2015
    Abstract
    In this paper we investigate the effect of the number of dissipative sites in an Abelian sandpile model. The dissipative sites are considered to be in the bulk rather than in the boundary. In such systems, statistics of avalanches smaller than a certain size obey a power law. We have seen that the exponents associated with these power law behaviors change slightly as the number of dissipative sites is decreased. We have found that the zero dissipation limits of these exponents are independent of size. Therefore we suggest that the previously-seen dependence of the exponent on the system size is because of the number of dissipative sites rather than the system size. Also it is observed that... 

    Annealed and quenched disorder in sand-pile models with local violation of conservation

    , Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 92, Issue 2 , August , 2015 ; 15393755 (ISSN) Moghimi Araghi, S ; Sebtosheikh, M ; Sharif University of Technology
    American Physical Society  2015
    Abstract
    In this paper we consider the Bak, Tang, and Wiesenfeld (BTW) sand-pile model with local violation of conservation through annealed and quenched disorder. We have observed that the probability distribution functions of avalanches have two distinct exponents, one of which is associated with the usual BTW model and another one which we propose to belong to a new fixed point; that is, a crossover from the original BTW fixed point to a new fixed point is observed. Through field theoretic calculations, we show that such a perturbation is relevant and takes the system to a new fixed point  

    Dynamic pull-in instability of electrostatically actuated beams incorporating Casimir and van der Waals forces

    , Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 224, Issue 9 , 2010 , Pages 2037-2047 ; 09544062 (ISSN) Moghimi-Zand, M ; Ahmadian, M.T ; Sharif University of Technology
    2010
    Abstract
    In this study, influences of intermolecular forces on the dynamic pull-in instability of electrostatically actuated beams are investigated. The effects of midplane stretching, electrostatic actuation, fringing fields, and intermolecular forces are considered. The boundary conditions of the beams are clamped-free and clamped-clamped. A finite-element model is developed to discretize the governing equations, and Newmark time discretization is then employed to solve the discretized equations. The static pull-in instability is investigated to validate the model. Finally, dynamic pull-in instability of cantilevers and double-clamped beams are studied considering the Casimir and van der Waals... 

    Anharmonic oscillator: A playground to get insight into renormalization

    , Article European Journal of Physics ; Volume 42, Issue 5 , 2021 ; 01430807 (ISSN) Moghimi Araghi, S ; Loran, F ; Sharif University of Technology
    IOP Publishing Ltd  2021
    Abstract
    In the presence of interactions the frequency of a simple harmonic oscillator deviates from the noninteracting one. Various methods can be used to compute the changes to the frequency perturbatively. Some of them resemble the methods used in quantum field theory (QFT) where the bare values of the parameters of the theory run when an interaction is added. In this paper, we review some of these techniques and introduce some new ones in line with QFT methods. Moreover, we investigate the case of more than one oscillator to see how the frequencies of small oscillations change when non-linear terms are added to a linear system and observe an interesting beat phenomenon in degenerate coupled... 

    Higher order and boundary scaling fields in the Abelian sandpile model

    , Article Journal of Physics A: Mathematical and Theoretical ; Volume 40, Issue 37 , 2007 , Pages 11277-11284 ; 17518113 (ISSN) Moghimi Araghi, S ; Nejati, A ; Sharif University of Technology
    2007
    Abstract
    The Abelian sandpile model (ASM) is a paradigm of self-organized criticality (SOC) which is related to c ≤ -2 conformal field theory. The conformal fields corresponding to some height clusters have been suggested before. Here we derive the first corrections to such fields, in a field theoretical approach, when the lattice parameter is non-vanishing, and consider them in the presence of a boundary. © 2007 IOP Publishing Ltd  

    Logarithmic conformal field theories near a boundary

    , Article Letters in Mathematical Physics ; Volume 53, Issue 1 , 2000 , Pages 49-57 ; 03779017 (ISSN) Moghimi Araghi, S ; Rouhani, S ; Sharif University of Technology
    Springer Netherlands  2000
    Abstract
    We consider logarithmic conformal field theories near a boundary and derive the general form of one and two point functions. We obtain results for arbitrary and two dimensions. Application to two-dimensional magnetohydrodynamics is discussed  

    Optimal-Robust Control of Drug Delivery in Cancer Chemotherapy

    , M.Sc. Thesis Sharif University of Technology Hosseini, Fatemeh (Author) ; Moradi, Hamed (Supervisor)
    Abstract
    Chemotherapy is a proven and effective systematic approach to treat various types of cancers. Despite its advantages, chemotherapy would kill healthy as well as cancer cells. To overcome this problem, different controlling strategies are implemented. This study aims to provide a medicine drug delivery schedule for chemotherapy (by designing a proper controlling system) based on the verifiable mathematical models. First, the dynamic model is analysed and stability points are reviewed. The selected model has five state variables and two inputs. In this study, the focus is on dynamic model analysis and obtaining an effective and appropriate treatment pattern by designing a proper controller. To... 

    Assessment of Seismic Retrofit Policies for Buildings

    , M.Sc. Thesis Sharif University of Technology Movahedi, Ali (Author) ; Kashani, Hamed (Supervisor)
    Abstract
    Occurrence of natural disasters such as earthquake could seriously damage most buildings especially those with insufficient resistance located in urban worn-out textures. In order to reduce unpleasant consequences of an earthquake, appropriate policies need to be considered to persuade the beneficiaries to follow retrofitting standards in the process of planning, designing, and construction of buildings. These policies shall be implemented through institutions in arbitrary or obligatory forms, by encouragement or penalty mechanisms. In order to consider these policies, first of all we need to identify the beneficiaries and their particulars. By studying and considering subjects discussed in... 

    Parametric study and computation of seismic performance factors of braced shear panels

    , Article Scientia Iranica ; Volume 23, Issue 2 , 2016 , Pages 460-474 ; 10263098 (ISSN) Hamed, A ; Mofid, M ; Sharif University of Technology
    Sharif University of Technology  2016
    Abstract
    By locating a steel shear panel on the intersection point of the X-braces, concentrically or eccentrically braced shear panel (CBFSP or EBFSP) is formed. In this paper, to perform parametric study, 1-story CBFSP and EBFSP models with span length greater or less than height are considered. Using linear static analyses, the effects of size and location of the shear panel on the lateral stiffness of the frame with respect to the moment resisting frame with the same member sections are investigated. Next, for 1- And 3-story models, maximum displacement, along with base shear, and the ratio between the dissipated energy and input energy are examined under 4 ground motion records. Behavior of the... 

    Nonlinear Vibration Analysis of Non-Uniform Beam in two Lateral Directions by Multiple Scales Method: Application in Wind Turbine

    , M.Sc. Thesis Sharif University of Technology Karimi, Behnam (Author) ; Moradi, Hamed (Supervisor)
    Abstract
    Environmental issues and energy crisis have led the world attention to the renewable energies; especially wind power, since they have low cost and high reliability. One of the most challenging areas of studying for wind power is to increase the capacity of wind turbines. As a result, over the years, wind turbines have got progressively larger. Vibration is one of the problems that reduces the life and efficiency of wind turbines; and the growing size of the blades has worsen this problem due to the importance of nonlinear effects in large scale wind turbines. Researchers have been constantly working on this issue in order to make the wind turbines more efficient. In this research, a...