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The Stochastic Properties Of Burgers And Kardar-Parisi-Zhang EquationsS In The Strong Coupling Limit
, Ph.D. Dissertation Sharif University of Technology ; Rahimi Tabar, Mohammad Reza (Supervisor)
Abstract
In this thesis, some aspects of the Burges and Kardar-Parisi-Zhang (KPZ) equations will be studied. At first we introduce Turbulence and describe historical view of Burgers and KPZ equations. Then in second section we study analytically the time issue of Burgers equation in 1+1-dimenssion. Then by using recently developed precise numerical methods by J. Bec and U. Frisch, we check result of previous section numerically. Our numerical simulation of the Burgers equation stirred by a kicking force support our analytical results. In small time scale our result show dynamical exponent of structure function z is one. This is the essence of the assumption first made by Sir G. I. Taylor in his 1938...
Application of the characteristic green's function technique in closed-form derivation of spatial green's function of finite dielectric structures
, Article CEM 2013 - Computational Electromagnetics International Workshop ; number 6617132 , 2013 , Pages 54-55 ; 9781479914326 (ISBN) ; Shishegar, A. A ; Faraji Dana, R ; Sharif University of Technology
2013
Abstract
A closed-form spatial Green's function for finite dielectric structures is derived by using a combination of the characteristic Green's function (CGF) and rational function fitting method (RFFM). CGF-RFFM represents both of the discrete and continuous spectrum contributions efficiently by using the modified VECTFIT algorithm. To obtain more accurate results, reflection coefficient correction due to the surface waves (SWs) incident on the the end-facet is considered. The main advantage of this method lies in its speed as well as accuracy. Excellent agreements with the rigorous method of moments (MoM) are shown in several examples
OmpF, a nucleotide-sensing nanoprobe, computational evaluation of single channel activities
, Article Physica A: Statistical Mechanics and its Applications ; Volume 457 , 2016 , Pages 215-224 ; 03784371 (ISSN) ; Mobasheri, H ; Nikouee, A ; Ejtehadi, M. R ; Sharif University of Technology
Elsevier B.V
2016
Abstract
The results of highthroughput practical single channel experiments should be formulated and validated by signal analysis approaches to increase the recognition precision of translocating molecules. For this purpose, the activities of the single nano-pore forming protein, OmpF, in the presence of nucleotides were recorded in real time by the voltage clamp technique and used as a means for nucleotide recognition. The results were analyzed based on the permutation entropy of current Time Series (TS), fractality, autocorrelation, structure function, spectral density, and peak fraction to recognize each nucleotide, based on its signature effect on the conductance, gating frequency and voltage...
Non-linear thermo-mechanical cylindrical bending of functionally graded plates
, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 222, Issue 3 , 2008 , Pages 305-318 ; 09544062 (ISSN) ; Nosier, A ; Sharif University of Technology
2008
Abstract
Based on the first-order non-linear von Karman theory, cylindrical bending of functionally graded (FG) plates subjected to mechanical, thermal, and combined thermo-mechanical loadings are investigated. Analytical solutions are obtained for an FG plate with various clamped and simply-supported boundary conditions. The closed form solutions obtained are very simple to be used in design purposes. The material properties are assumed to vary continuously through the thickness of the plate according to a power-law distribution of the volume fraction of the constituents. The effects of non-linearity, material property, and boundary conditions on various response quantities are studied and...
Taylor's frozen-flow hypothesis in Burgers turbulence
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 77, Issue 6 , 2008 ; 15393755 (ISSN) ; Niry, M. D ; Davoudi, J ; Rahimi Tabar, M. R ; Masoudi, A. A ; Sreenivasan, K. R ; Sharif University of Technology
2008
Abstract
By detailed analytical treatment of the shock dynamics in the Burgers turbulence with large scale forcing we calculate the velocity structure functions between pairs of points displaced both in time and space. Our analytical treatment verifies the so-called Taylor's frozen-flow hypothesis without relying on any closure and under very general assumptions. We discuss the limitation of the hypothesis and show that it is valid up to time scales smaller than the correlation time scale of temporal velocity correlation function. We support the analytical calculation by performing numerical simulation of the periodically kicked Burgers equation. © 2008 The American Physical Society
Flutter of functionally graded open conical shell panels subjected to supersonic air flow
, Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 227, Issue 6 , 2013 , Pages 1036-1052 ; 09544100 (ISSN) ; Shokrollahi, H ; Sharif University of Technology
2013
Abstract
In this article, analysis of supersonic flutter of functionally graded open conical shell panels with clamped and simply supported edges is presented. The aeroelastic stability problem is formulated based on first-order shear deformation theory as well as classical shell theory and solved using Galerkin method. The effects of the volume fractions of constituent materials, the semi-vertex and subtended angles, thickness, and length on the flutter of the functionally graded conical shell panel are investigated. It is shown that the discrepancies between the results of the present classical shell theory and first-order shear deformation theory for the critical aerodynamic pressure are generally...
Three-dimensional elasticity analysis of functionally graded rotating cylinders with variable thickness profile
, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 226, Issue 3 , 2012 , Pages 585-594 ; 09544062 (ISSN) ; Asghari, M ; Sharif University of Technology
Abstract
A three-dimensional elasticity solution for the analysis of functionally graded rotating cylinders with variable thickness profile is proposed. The axisymmetric structure has been divided in several divisions in the radial direction. Constant mechanical properties and thickness profile are assumed within each division. The solution is considered for four different thickness profiles, namely constant, linear, concave, and convex. It is shown that the linear, concave, and convex thickness profiles have smaller stress values compared to a constant thickness profile. The effects of various grading indices as well as different boundary conditions, namely solid, free-free hollow and fixed-free...
Probing rough surfaces: Markovian versus non-Markovian processes
, Article New Journal of Physics ; Volume 10 , August , 2008 ; 13672630 (ISSN) ; Shirazi, A. H ; Jafari, G. R ; Sharif University of Technology
2008
Abstract
We demonstrate that Markov processes play a fundamental role in probing rough surfaces and characterizing their topography. The surface topography obtained by a probe, as in the atomic force microscopy (AFM) technique, is based on the probe-surface interactions. When the size of the probe tip is comparable with the height of the surface fluctuation, the surface image can be aberrated from its origin. Due to the tip effect, there is a crossover in the structure function of the surface. For scales smaller than the Markov length -the minimum length scale over which a process is Markovian - the stochastic function that describes a rough surface is non-Markovian, whereas for length scales larger...
Finding correlation between protein protein interaction modules using semantic web techniques
, Article 13th International Computer Society of Iran Computer Conference on Advances in Computer Science and Engineering, CSICC 2008, Kish Island, 9 March 2008 through 11 March 2008 ; Volume 6 CCIS , 2008 , Pages 1009-1012 ; 18650929 (ISSN); 3540899847 (ISBN); 9783540899846 (ISBN) ; Moaven, S ; Abolhassani, H ; Sharif University of Technology
2008
Abstract
Many complex networks such as social networks and computer show modular structures, where edges between nodes are much denser within modules than between modules. It is strongly believed that cellular networks are also modular, reflecting the relative independence and coherence of different functional units in a cell. In this paper we used a human curated dataset. In this paper we consider each module in the PPI network as ontology. Using techniques in ontology alignment, we compare each pair of modules in the network. We want to see that is there a correlation between the structure of each module or they have totally different structures. Our results show that there is no correlation...
Recent advances in the modification of carbon-based quantum dots for biomedical applications
, Article Materials Science and Engineering C ; Volume 120 , 2021 ; 09284931 (ISSN) ; Sedighi, O ; Tabatabaei Rezaei, N ; Abedini, A. A ; Malek Khachatourian, A ; Toprak, M. S ; Seifalian, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Carbon-based quantum dots (CDs) are mainly divided into two sub-groups; carbon quantum dots (CQDs) and graphene quantum dots (GQDs), which exhibit outstanding photoluminescence (PL) properties, low toxicity, superior biocompatibility and facile functionalization. Regarding these features, they have been promising candidates for biomedical science and engineering applications. In this work, we reviewed the efforts made to modify these zero-dimensional nano-materials to obtain the best properties for bio-imaging, drug and gene delivery, cancer therapy, and bio-sensor applications. Five main surface modification techniques with outstanding results are investigated, including doping, surface...
Recent advances in the modification of carbon-based quantum dots for biomedical applications
, Article Materials Science and Engineering C ; Volume 120 , 2021 ; 09284931 (ISSN) ; Sedighi, O ; Tabatabaei Rezaei, N ; Abedini, A. A ; Malek Khachatourian, A ; Toprak, M. S ; Seifalian, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Carbon-based quantum dots (CDs) are mainly divided into two sub-groups; carbon quantum dots (CQDs) and graphene quantum dots (GQDs), which exhibit outstanding photoluminescence (PL) properties, low toxicity, superior biocompatibility and facile functionalization. Regarding these features, they have been promising candidates for biomedical science and engineering applications. In this work, we reviewed the efforts made to modify these zero-dimensional nano-materials to obtain the best properties for bio-imaging, drug and gene delivery, cancer therapy, and bio-sensor applications. Five main surface modification techniques with outstanding results are investigated, including doping, surface...
AFM spectral analysis of self-agglomerated metallic nanoparticles on silica thin films
, Article Current Nanoscience ; Volume 6, Issue 1 , 2010 , Pages 116-123 ; 15734137 (ISSN) ; Sharif University of Technology
2010
Abstract
Stochastic parameters of self-agglomerated metallic nanoparticles on a dielectric film surface were studied using atomic force microscopy (AFM) analysis. In this regard, the rough surfaces including the nanoparticles were analyzed and characterized using structure function, roughness exponent and power spectrum density of the AFM profiles and their gradients, for different metal concentrations and heat treatment temperatures. The diffusion parameters, such as activation energy, of the nanoparticles initially accumulated on the surface into a porous and aqueous silica thin film were obtained using the AFM spectral analysis of the profiles and their gradients. It was found that the tip...