Sharif Digital Repository

Obstruction of Left Anterior Descending artery (LAD) due to thrombosis or atherosclerotic plaques is the leading cause of death world–wide. Targeted delivery of drugs through micro- Nano-particles holds noteworthy promise which can make clot busting or the restenosis treatment with minimal toxicity possible. In this work, Fluid-Structure Interaction (FSI) simulations of blood flow through a patient-specific reconstructed geometry of LAD artery have been conducted using a non-Newtonian hematocrit (HCT) dependent model for blood. Based on physiological facts, 25, 45 and 65 percentages of HCT were assumed as acceptable representations of anemic, healthy and diabetic blood conditions,... 

Discovering new medicines and generally medical researches, are time consuming and expensive. But recent achievements in cell culturing methods and micro and nano-engineering techniques have enabled the researchers to investigate new medicines in a lesser time and price. Huh et al. successfully fabricated the lung on chip device. This device is consisted of three chambers. The middle chamber is separated in two equal parts and side chambers were considered in order to apply normal breathing. Periodic deformation was needed to apply the natural condition of cultured cells by expansion and contraction. Numerical simulation was needed to investigate the properties of flow in this kind of... 

A highly reliable tool for transient simulation is vital in the safety analysis of a nuclear reactor. Despite this fact most tools still use diffusion theory and point-kinetics that involve many approximations such as discretization in space, energy, angle and time. However, Monte Carlo method inherently overcomes these restrictions and provides an appropriate foundation to accurately calculate the parameters of a reactor. For this reason, in this thesis, a dynamic Monte Carlo code named MCSP (Monte Carlo dynamic Simulation of Particles tracking) is developed for both the steady state and time-dependent simulation of particle (neutrons, photons and electrons) tracking in an arbitrary 3D... 

This study aimed to investigate the efficiency of machine learning algorithms in capturing the dynamics of water particles' age distribution and in estimating the time series of median travel time (MTT) in river basins. The mechanism of solute transport in a catchment does not follow the hydrograph shape of the catchment and depends on the spatial and temporal distribution of solute resident time. The equations governing the age dynamics of water particles discharged from a catchment have been presented analytically in recent research. These equations showed that the transfer of solutes depends on various factors, including climatic conditions, basin topography, and basin vegetation. Also,... 

StorAge selection (SAS) functions describe the mechanism by which water particles with different ages exit a hydrological system through outfluxes such as streamflow and evapotranspiration (ET). The shape of the ET SAS functions affects the storage residence time distributions, ET travel time distributions, and discharge travel time distributions that control the hydrochemical dynamics of water. They also carry fundamental information to understand the response behavior of the system, and are affected by processes such as precipitation, outflow, ET, as well as the physical properties of the system. To better understand the shape of these functions, other important factors such as the type... 

The prediction of deposition efficiency of submicron particles in the pulmonary alveoli has received special attention due to its importance for drug delivery systems, and for assessing air pollutants health risks. In this work, the pulmonary alveoli of a healthy human are idealized by a three dimensional honeycomb like configuration and a fluid-structure interaction analysis is performed to study the normal cyclic breathing hydrodynamics. A viscoelastic model is used for the mechanical behavior of alveolar wall tissue. In contrast to previous works in which the inlet flow rate is predefined, in this model a negative pressure is imposed on the outside surface of the alveolus which causes air... 

The stirred tank is one of the oldest device that widely used in different industrial. a special kind of stirred tank that clled bioreactor refer to any device which supplies required biological, biochemical and biomechanical engineered product. Since the aim of bioreactor is produce of desired biological product, it is essential to accurate monitoring internal and external transfer of nutrient, heat transfer, fluid velocity, Strain stress and medium PH. good design and application of bioreactor depend on product, organism, conditions for produce desired product and scale of produce. also cost of capital and function cost are important in bioreactor design. one of the most important... 

In this thesis, flow hemodynamic parameters and white blood cell deposition on the 3- D of coronary artries of heart coronary walls are studied. At first, numerical simulation of blood flow and without the presence of white cells is performed. Then, using the Lagrangian approach, white blood cells as solid particles are tracked considering forces such as drag force, weight, buoyancy, Saffman lift force, virtual mass in one way coupling method. this particle representive of white blood cells and play significant role in low density lipoprotein (LDL) deposition.The results show that a low shear region occurs on myocardial wall. maximum flow velocity near the bifurcation towards epicardial wall... 

In respiratory system of live bodies, different mechanical phenomena such as air suction, diffusion and deposition of particles and transport of species between air and blood take place. Furthermore, the geometry of lung is a complex and multi scale geometry. In order to reduce these complexities, the acinus behavior is transformed to numerical functions which can be used as boundary conditions for simulating upper generations of the lung. Hence, in current study, the air flow suction of the lung is described as a function of the mechanical properties of the lung tissue. This task is fulfilled by modeling the flow for different Elastic moduli and taking fluid structure interaction into... 

In this thesis, by focusing on the hydraulics of three phase flow in vertical tubing to investigate asphaltene deposition problem, the solid particles behaviors in a turbulent flow is fully studied. Reasonable size distribution for particles (based on previous works and researches) was assumed and a model for 2 sections of a Marrat oil field well to evaluate their asphaltene deposition problem was developed. Three phase liquid-gas-solid flow in the well tubing was simulated. Asphaltene deposition profile on the well tubing, mean and maximum of the deposition rate and particle concentrations in the flow regime were calculated and compared with real field data. Better agreement with field data... 

This project related to gas purification according to difference in the deposition point in the fludized bed.The reason for choosing fluidized bed is increasing erosion on wall of bed & increasing on heat transfer compared to other heat exchangers.Separation process, by cooling the wall causes the self- deposition gas phase shifts to solid phase. Solid formed on the wall, act as an insulating layer and greatly reduces the heat transfer therefore part of vessel not used. To solve this problem, the fluidized bed system is offered because the fluid particles can remove the insulating layer beside improving convection heat transfer coefficient. In this work we studied the quantative of erosion...