Sharif Digital Repository

This paper presents finite-element simulation results for hydraulic fracture’s initiation, propagation at reservoirs with damaged zone and naturally fractured reservoirs that likely finds in Iranian oil fields. To address this objective, a two-dimensional poro-elastic model was solved and cohesive zone modeling was used as the methodology for simulation fractures. This enables us to assign individual criteria for fracture initiation and propagation in each model. Our results demonstrate that hydraulic fracturing is not useful in reservoir with strongly damaged zone around the wellbore, because pore pressure increases at that zone and plastic flow of fracture wall happens, so it is better to... 

Flows which density difference in a gravity field is their driven force are called Density Currents. Such flows are present in both nature and man made environments. Due to their importance, there have been large efforts to analyse them in both experimental and numerical way. In the present thesis, Smoothed Particle Hydrodynamics (SPH) is introduced as a new tool to simulate such flows. As the method is Lagrangian and particle based, simulation of Density Currents with particles can be addressed more naturally that can be accounted as the method preference to traditional mesh based methods. SPH projection method is incorporated to impose incompressibility. To precisely simulate Density... 

Today, obesity, as a major global health challenge, affects more than 30 percent of the world's population. To investigate the effect of obesity on spinal function, a common method is motion analysis (kinematic method). This method is based on the claim that the abnormal mechanical function of the spine is directly related to its abnormal motions.The aim of this study is to measure and compare the range of motions (RoMs) of different segments of the spine in all anatomical plates between obese and normal individuals, as well as to calculate and compare some motion rhythms between the lumbar spine and the pelvis in these two groups. Comparing the posture of the spine between obese and normal... 

The objective of this research is to design a drug delivery system that allows anti-inflammatory drugs to be injected directly into the joint (intra-articular injection) for the treatment of arthritis so that reduce the side effects associated with oral consumption of these drugs, increase the duration of drug retention in the joint environment, and reduce the side effects caused by repeated injections while improving effectiveness. To achieve this, first, desirable features were determined by considering the anatomy of the joint environment, the biological changes caused by the disease, and reviewing published articles and commercial products in the field; appropriate drug and raw materials... 

Despite many advantages of granular sludge in anaerobic reactors (e.g. UASB), over the past few years research attention had turned towards developing aerobic granular sludge. Although much research is carried out on the formation of aerobic granules, less work is reported on how to enhance granules characteristics such as increasing in granule size, concentration, durability and stability. The aims of this study are to investigate the effects of cationic polymer on granule formation and the way to improve granule characteristics. For this purpose two SBR reactors (0.15 m diameter and 1.8 m height, R1 and R2) were used by feeding synthetic wastewater (diluted molasses, COD ranging from 1400... 

Multiple distortion coding is a promising solution for video transmission over lossy channels. In MDC multiple descriptions of a source are generated which are independently decodable and mutually refinable. When all descriptions are available, the corresponding quality is called central quality; otherwise it is called side quality. Generally, there exist a trade-off between side and central quality in all MDC schemes. The MDC methods which provide better central-side quality trade-off are of more interest to the designers.In this thesis a new MDC scheme is introduced which has better trade-off between side and central quality. In other words, for the same central quality, it provides higher... 

The aim of this project is to fabricate and study heterogeneous CaO-based nanocatalysts with lithium and zinc enhancers for the esterification reaction of rapeseed oil and methanol to produce biodiesel as a renewable and alternative fuel for fossil fuels. Is. First, Zn-Li / CaO catalysts with weight ratio Li: Zn: CaO, 2: 2: 7 and by combining different percentages of Li100% promoter, Li75% -Zn25%, Li50% -Zn50%, Li25% -Zn75%, 100% Zn were made on the basis of CaO by wet inoculation. Characterization tests to evaluate the structure and characterization such as X-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (EDX) spectroscopy, Bruner-Emmett-Teller... 

The network of actin filaments is one of the three elements of the Cytoskeleton and plays a role in cell shape and migration. The actin network is dynamic; it (de)polymerizes, and in migrating and spreading cells, it is in a retrograde motion from the cell periphery toward cell nucleus. Adhesion points, which link the cytoskeleton to the extracellular matrix, interact with the actin retrograde flow. Actin filaments can be identified in two distinct regions in which their structure, flow velocity, driving force and size of the adhesions are different; the outer region is called Lamellipodium and the inner one Lamellum. In macro scale and regarding spreading cells, considering adhesions... 

The rapid growth of e-commerce and the increasing demand from customers for fast and accurate order deliveries have significantly heightened the importance of warehouse operation optimization. Among various warehouse activities, product layout and order-picking processes play a crucial role in reducing response time and enhancing productivity. This research proposes a four-stage approach to improve the performance of e-commerce warehouses. In the first stage, efficient products for warehouse storage were identified using the Data Envelopment Analysis (DEA) method. In the second stage, products were categorized based on common order patterns, and in the third stage, they were allocated to...