Sharif Digital Repository

Kidney is one of the most complicated organs in terms of functionality and physiology due to its complicated unique vascular structure. Previous investigations have focused on specific characteristics like length and diameter. Most of these methods are based on Image Processing techniques which prevent a comprehensive study in growth and changes of the vascular system. Lindenmyaer system (L-system) is a parallel rewriting system and a type of formal grammar and had been used to create graphs and natural patterns. By absorbing the physiological characteristics of the kidney and integrating them into parametric L-system, a highly dense and accurate vascular system could be generated with few... 

The objective of this study is development of a probabilistic framework that facilitates the investigation of the post-earthquake performance of a network of hospitals using the Hospital Network Resilience index which quantifies the ability of the hospitals to provide treatment to earthquake victims. Disasters such as earthquakes can damage the infrastructure systems of a community, disrupt the functionality, and lead to various direct and indirect economic, social and socioeconomic consequences. Over a decade, natural disasters such as earthquakes are estimated to have caused $1.3 trillion economic losses. The social and socioeconomic losses of natural disasters are equally significant as... 

In this research to solve the problems related to titanium implants, a new type of dental implant was designed and fabricated by using shape memory and pseudoelasticity properties of porous nitinol alloys. The elastic modulus of this implant (equal to 0.8 GPa) is similar to the cancellous jaw bone (equal to 0.3-1 GPa) which causes a normal distribution of stress and prevents bone resorption. The current approach is use of radius variation to facilitate implant surgery. These radial changes are created by using one way shape memory effect. First, the implant enters the jaw cavity by decreasing the radius and after reaching the body temperature and restoring the initial shape, the radius of... 

In this study the spouted bed with draft tube was investigated by discrete phase model for particulate phase and was tried to simulate the spouted bed with high precision by using of experimental data. So, the most accuracy combination of different parameters and sub models was specified. According to this study, the dispersed k-ԑ turbulence model and standard wall function make best prediction. Gidaspow drag model was used for prediction interaction between phases. This study include the effect of Saffman lift force and Rubinow-keller model was chosen for coefficient of Magnus lift force. In Addition, the solid movement pattern was studied in different area of bed especially in fountain... 

The increase in demand for liquid hydrocarbon fuels in recent years in the transportation sector as well as in industry has led to an increase in the concentration of pollutants in the atmosphere. Sulfur oxides are known as one of the most challenging pollutants in the world today. In recent years, with the increase in the amount of pollutants in the air and the problems caused by them, which endanger the health of the society, sensitivities have arisen regarding the entry of pollutants into the air. Therefore, the Environmental Protection Organization has set specific standards regarding the allowed amount of sulfur in liquid fuels. One of the new ways to reduce the amount of sulfur in... 

The behavior of two-phase flow in porous media is influenced by the flow functions. Especially in fractured porous media where the relative permeabilities of the phases in the fracture and matrix are different, the flow behavior is significantly affected by these functions. On the other hand, the properties of the fluid and the fracture, such as length, orientation, and roughness of the fracture, also play an important role in determining the values of relative permeabilities and, consequently, the behavior of two-phase flow. However, the influence of fracture geometric properties on the relative permeability curves in fractured porous media is not well understood. In this study, firstly, a... 

Flapping-wing pseudo-insects, given their multi-body and periodic aerodynamic nature, are considered some of the most complex aerial systems. Many of the aerodynamic and dynamic phenomena governing these creatures remain elusive despite decades of research by engineers. One particularly fascinating phenomenon is vibrational stabilization, which plays a significant role in the intrinsic stability of these birds. In fact, this phenomenon functions as a form of an open-loop asymptotic stability system. This research investigates the existential nature of this phenomenon and its impact on the stability of an oscillating inverted pendulum and a six-degree-of-freedom model of a flapping-wing...