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heterogeneous-model
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Experimental Analysis of Immiscible Displacements of Heavy Oil in Heterogeneous Porous Media under Ultrasonic Effect
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Siroos (Supervisor) ; Ghazanfari, Mohammad Hossein (Supervisor)
Abstract
In the recent years, there has been an increasing attention toward usage of ultrasonic for enhanced oil recovery practices. But, thorough knowledge of active mechanisms and spreading and characterization of developed fingers during this practice is not available. From the other hand, due to limited amount of light oil fields, more attentions towards recovery from heavy oils is the need of the hour. Documents show that the big issues during the enhanced oil recovery from heavy crudes are high density of reservoir oil as well as poor development of fingers during injection due to high mobility ratios. In this study, results of ultrasound effect on the heavy oil recovery and its effect on the...
Role of Synchronous Sub-network in the Propagation of Synchronization to the Neuronal Population
, M.Sc. Thesis Sharif University of Technology ; Moghimi Araghi, Saman (Supervisor)
Abstract
Epilepsy is one of the most common non-communicable neurological disorders, characterized by recurrent seizure symptoms. Although much progress has been made in the diagnosis, control, and treatment of epilepsy in recent years, the exact mechanism of seizures, the specific method for early diagnosis of epilepsy and related syndromes, and definitive treatment for all patients are not yet known. In a type of seizure known as focal seizure, the electrical activity of neurons at the epilepsy focus synchronizes abnormally, and this synchronization can propagate to other regions of the brain in a process called secondary generalization, which finding a method for its prevention is our essential goal...
The Impacts of Banking on the Effects of Monetary Policy on Inequality: A Study in a HANK Framework
, M.Sc. Thesis Sharif University of Technology ; Madanizadeh, Ali (Supervisor) ; Mahmouzadeh, Amineh (Supervisor)
Abstract
This study wants to analyze the effects of the banking system on the transmission of monetary policy and its impact on wealth inequality. We use a continuous time heterogeneous framework with heterogeneity for households and capital producers. The model is an extended version of a two-asset heterogeneous agent New Keynesian model with heterogeneous capital producers and a bank with liquidity transformation. The production block consists of a final-good producer, intermediate-good producers, and capital-good producers. Capital good producers could get loans from the bank but have a borrowing constraint. We found that a) an expansionary monetary policy increases the issued loans, which leads...
Catalyst deactivation in industrial combined steam and dry reforming of natural gas
, Article Fuel Processing Technology ; Vol. 120 , 2014 , pp. 96-105 ; ISSN: 03783820 ; Baghalha, M ; Sharif University of Technology
Abstract
The catalyst's performance and deactivation in a Midrex® industrial fixed bed reactor were investigated for the combined steam and dry reforming of natural gas using a one-dimensional heterogeneous model. The results demonstrate that there is a strong tendency for the catalyst's deactivation by carbon formation originating from methane decomposition. However, kinetic modelling of the combined reforming process shows that only a fraction of the catalyst in the industrial reactor is required for the reactions to reach an equilibrium state in the reformer. Hence, as the catalyst is deactivated at the reactor entrance area, the reaction zone gradually moves forward and still allows for...
An efficient and robust method for optimizing the number of non-linear iterations for simulating highly heterogeneous naturally fractured reservoirs
, Article Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2020, ADIP 2020, 9 through 12 November ; 2020 ; Eslahi, R ; Bakhtiari, M ; Alizadeh, A ; Zeinali, M ; Madani, M ; Rajabi, H ; Sharifi, E ; Mortezazadeh, E ; Mahdavifar, Y ; Sharif University of Technology
Society of Petroleum Engineers
2020
Abstract
For speeding up the complex fractured reservoir simulating, we have given more attention to reducing runtime and improving efficiency of the solver. In this work, we describe an improved and computationally efficient version of Newton's method, which reduces the non-linear iteration count, increases time steps, and furthermore reduces time spent in nonlinear loops of reservoir simulating. Safeguarded variants of Newton's method which have used in current reservoir simulators cannot guarantee convergence of the solution, especially in highly heterogeneous, detailed and fractured reservoirs. In such simulators time step chopping is often observed. From other hand, with growing complexity,...
A quantitative and qualitative comparison of coarse grid generation techniques for numerical simulation of flow in heterogeneous porous media
, Article SPE Reservoir Simulation Symposium 2009, The Woodlands, TX, 2 February 2009 through 4 February 2009 ; Volume 1 , 2009 , Pages 55-73 ; 9781605607771 (ISBN) ; Mahani, H ; Firoozabadi, B ; Landmark; HALLIBURTON ; Sharif University of Technology
2009
Abstract
Applying upscaling techniques is an undeniable demand in reservoir simulation, considering the difference between level of details in a geological model and level of details that can be handled by reservoir simulators. Upscaling reservoir model involves first constructing a coarse grid by employing gridding algorithms and then computing average properties for coarse grid blocks. Although various techniques have been proposed for each of these steps, one has to be aware of strengths and weaknesses of each technique before attempting to apply them. In this paper, we focus on different gridding methods and evaluate their performances. Three main grid generation techniques are considered:...