Sharif Digital Repository

Interfacial phenomena and properties of interphase surfaces in dynamic mode play an important role in industrial processes that include gas-liquid and liquid-liquid multiphase flows. As well as, interface knowledge leads to better understanding of natural and fundamental phenomena. The present study has been performed for understanding about dynamic behavior of interphase surfaces in the presence of nanoparticles and hexane vapor in gas-liquid dispersion systems. In this research, rising bubble method has been used as one of the most conventional techniques. Accordingly, aqueous solutions of nanosilica were prepared in concentrations of 50, 100, 200, 400 and 1200 ppm as continuous phase... 

The objective of OCR systems is to retrieve machine-encoded text from a raster image. Despite the abundance of powerful OCR algorithms for English, there are not many for Farsi. Our proposed algorithm is comprised of pre-processing, line detection, sub-word detection and segmentation, feature extraction and classification. Furthermore, hardware implementation and acceleration of this system on a GPGPU is presented. This algorithm was tested on 5 fonts including Titr, Lotus,Yekan, Koodak and Nazanin and an average accuracy above 90% was achieved  

Dynamic properties such as the natural frequency of a structure have a significant role in the design process. The importance of this consideration is because of resonance. In this case, the amplitude of the vibration is magnified to levels that may lead to a catastrophic event. While the usual design process depends on the collected experiences and statistical data, a developing trend is to implement smart technologies to develop smart structures that are capable of self-monitoring, diagnostics and repair. Smart material components such as shape memory alloys (SMAs) and piezoelectric ceramics are increasingly being used by vibration control practitioners. Shape memory alloys are applied as... 

Concentric steel braces and brace-type dampers are often applied to the upgrading of reinforced concrete frames subjected to lateral loads. These braces may develop High axial tension forces, and transferring them appropriately to the existing beam– Column joints is a key challenge. This paper investigates a solution for connecting the end-plate of the steel brace with the frame, using shear-key plates fixed to the concrete with anchor bolts, and a low friction material inserted between the end-plates and the shear-key plates. The presence of the low friction material impedes the development of tension forces in the anchor bolts and ensures that they are basically subjected to shear forces.... 

In the present study, analytical solutions within first-order shear deformation plate theory (FSDT), are presented for the linear and nonlinear asymmetric bending of functionally graded circular plates subjected to thermo-mechanical loading and boundary layer phenomenon is also investigated. To this end, cylindrical bending of long rectangular FG plates is also considered to study the perturbation technique which is used here to solve the nonlinear equations. Functionally graded materials are mostly used in high temperature environments and the study of their behavior under thermal and mechanical loadings and in small and large deflection ranges has become very important. Here, the linear... 

In this study, linear and nonlinear mechanical behavior of moderately thick annular sector plates made of functionally graded materials is investigated. In linear analysis, based on first order shear deformation theory, governing equation with two different approaches are derived. In first approach, by application of extended Kantorovich method (EKM), displacements field variables are expressed as separable function of and together, and two sets of ordinary differential equations (ODEs) by using the principle of minimum total potential energy are derived. In the second approach, within FSDT and using the principle of minimum total potential energy, the governing partial differential... 

In this study the free vibration of annular sector plates made of functional materials with using the extended Katrovich method is investigated for a variety of boundary conditions. For this purpose, based on the first order shear deformation theory and Hamilton's principle, equations of motion that they are five differential equations and coupled, are derived. Due to the difficulty of the equations obtained by applying extended kantrovich method on these equations, two ordinary differential equations obtained, the two categories combined fixed and simple boundary conditions will be solved by using generalized differential quadrature and in an iterative process system natural frequency is...