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Synergistic effect of like and opposite charged nanoparticle and surfactant on foam stability and mobility in the absence and presence of hydrocarbon: a comparative study
, Article Journal of Petroleum Science and Engineering ; Volume 166 , July , 2018 , Pages 433-444 ; 09204105 (ISSN) ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier B.V
2018
Abstract
The aim of this study is to compare the synergistic impact of like and opposite-charged nanoparticle and surfactant systems on enhancing stability and mobility of foam in the absence and presence of oil which is not sufficiently discussed in the available literature. Stability of nanoparticle dispersion is examined at various levels of pH when nanoparticle and surfactant are in like and opposite-charged conditions. In situ modification of silica nanoparticle by opposite-charged surfactant is analyzed. Static stability tests as well as Hele–Shaw cell are employed to understand how nanoparticle and surfactant charges may control the stability and mobility of foam when oil is present/absent....
Experimental Investigation of Improvement of Stability and Performance of Foam Using Nano-particles to Enhance Oil Recovery
, M.Sc. Thesis Sharif University of Technology ; Ghazanfari, Mohammad Hossein (Supervisor)
Abstract
Using foam for reducing undesirable effects of fingering and gravity segregation in enhanced oil recovery through gas injection has attracted a rapidly increasing interest in recent years. Lack of stability of foam often limits its application. However there is a lack of systematic study of effects of unmodified and in-situ modified silica nano-particle on foam stability and foam behavior in the presence and absence of oil and also polymer effects from the prospective of analysis of foam dynamic stability, size of foam bubbles, and foam flow behavior in Hele – Shaw cell. Main objectives of this study are mechanistic investigation of effects of polymer – surfactant systems and in-situ...
Monitoring the behaviour of anionic polymer-anionic surfactant stabilized foam in the absence and presence of oil: Bulk and bubble-scale experimental analyses
, Article Canadian Journal of Chemical Engineering ; Volume 97, Issue S1 , 2019 , Pages 1386-1398 ; 00084034 (ISSN) ; Hossein Ghazanfari, M ; Shafiei, Y ; Sharif University of Technology
Wiley-Liss Inc
2019
Abstract
The present study aims at monitoring the bulk and bubble-scale behaviour of anionic polyacrylamide-sodium dodecyl sulphate stabilized foam in the absence and presence of oil. Dynamic stability tests provided results indicating that polymer increases the foam dynamic stability and decreases the drainage. Oil slows down the drainage rate of polymer-surfactant foam. In the absence of oil, foam is drained gradually/smoothly whereas remarkable fluctuations are evident in drainage graphs when oil is present. The Hele-Shaw cell was employed to conduct bubble-scale as well as statistical analyses on how foam texture is influenced by a polymer-surfactant system and hydrocarbon. Bubble-scale analyses,...
Modeling of Non-Darcy flow through anisotropic porous media: Role of pore space profiles
, Article Chemical Engineering Science ; Volume 151 , 2016 , Pages 93-104 ; 00092509 (ISSN) ; Hassani, A. H ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
Excess pressure drop induced by inertial effects limits the applicability of Darcy's law for modeling of fluid flow through porous media at high velocities. It is expected such additional pressure drop is influenced by pore/morphology of porous media. This work concerns with fundamental understanding of how throat curvature affects intrinsic properties of porous media at non-Darcy flow conditions using network modeling. Conical, parabolic, hyperbolic, and sinusoidal capillary ducts with three types of imposed anisotropy are used to construct the network in a more realistic manner. Solutions of one dimensional Navier-Stokes equation for incompressible fluid flow through converging/diverging...
A new insight into onset of inertial flow in porous media using network modeling with converging/diverging pores
, Article Computational Geosciences ; Volume 22, Issue 1 , February , 2018 , Pages 329-346 ; 14200597 (ISSN) ; Hassani, A. H ; Ghazanfari, M. H ; Sharif University of technology
Springer International Publishing
2018
Abstract
The network modeling approach is applied to provide a new insight into the onset of non-Darcy flow through porous media. The analytical solutions of one-dimensional Navier-Stokes equation in sinusoidal and conical converging/diverging throats are used to calculate the pressure drop/flow rate responses in the capillaries of the network. The analysis of flow in a single pore revealed that there are two different regions for the flow coefficient ratio as a function of the aspect ratio. It is found that the critical Reynolds number strongly depends on the pore geometrical properties including throat length, average aspect ratio, and average coordination number of the porous media, and an...
Statistical MPSoC Architecture Optimization under Process Variation
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
In nanometer technologies, the effect of process variation is observed in Multi-Processor System on Chip (MPSoC) in terms of variation in processors‟ frequency and leakage power. Traditionally, only worst case values of the system parameters were concerned and a worst-case optimization algorithm was employed for an application under design. As previous researches have shown these algorithms are not optimal in terms of parametric yield compared with newly employed statistical optimization algorithms. In this project, we have considered the problem of simultaneously selecting MPSoC architecture (which includes type and number of processors and the communication media) and task and...
Process-Variation-Aware Configuration Selection of Configurable MPSOC for Power-Yield Maximization
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
Process Variation is seen as statistical variations in leakage current and delay of transistors in nano-scale technologies. The amount of process variations increase as the size of transistors decrease by technology scaling such that those effects can be seen in frequency of MPSoC (Multi-Processor System-on-Chip) cores and their leakage power deviation. These variations cause the tasks duration and power consumption fluctuate in different processors in an MPSoC instance. Consequently, some chip instances of the same MPSoC may consume more time and power than their considered limitations. Hence considering the process variation is necessary and required for MPSoC optimization at different...
Thermal- and Process-Variation-Aware Data Center Energy Reduction
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
Size and number of high-performance data centers are fast growing all over the world in recent years. The growth in the leakage power consumption of servers along with its exponential dependency on the ever increasing process variation in nanometer technologies have made it inevitable to move toward variation-aware power reduction strategies. In this thesis, we simultaneously apply thermal- and variation-aware server placement and chassis consolidation methods to reduce total power consumption of data centers. We introduce two server placement heuristics as well as an Integer Linear Programming (ILP)-based server placement method based on power consumption of each server and the data center...
Accelerating Network Firewalls
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
With the proliferation of Internet-based applications and malicious attacks, security has become one of the most influential aspects in the network and, it should be considered from the beginning steps of designing the network infrastructure. Based on the fact that pattern matching is considered as one of the most important roles of security devices or applications, it becomes an important procedure in firewalls that have been classified as security equipments which adopt a security mechanism in order to restrict the traffic exchanged between networks and particular users or certain applications. While the trend of using compressed traffic is drastically increasing, this type of traffic is...
Security Analysis of an Offline Mobile Micro-Payment System
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
Mobile payment has already become an integral part of modern life for daily banking needs. Many payment systems are now providing financial services to customers. Most of these systems need and rely on online network access to provide their services. On the other hand, there are many regions in the world that have no network access or the network quality is poor with intermittent failures. Customers in these areas are unable to transfer money or buy goods and pay for it using their mobile devices by such above systems. This motivated us to find a way for transferring money without need for network availability. As a result we devised an offline peer-to peer mobile payment system (MobiPOS)....
Reducing Energy Consumption Considering Stochastic Distribution of Network Traffic
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
In the past few years, because of the high energy price in data centers, optimizing energy consumption has become of real importance. The disproportionate energy consumption of network devices to their utilization has led them to become one of the biggest consumers of energy inside data centers. On the other hand, the stochastic nature of network traffic among virtual machines has made the assumption of known or fixed communication volume superficial. In this research we considered a stochastic distribution of network traffic and communication volume among virtual machines trying to change the communication inside data center to communication inside hosts. Initially, we start by evaluating...
Energy-Aware Service Job Scheduling in Data Center with Distributed UPS and Renewable Energy
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
Recently, The Earth has become warm rapidly over the past few years. This global warming is not only caused by natural phenomena, and further increased by humans and the amount of greenhouse gases in the atmosphere. Around 40 to 50 percent of energy consumption is related to information technology and communications. However, the rapid growth of electricity consumption in data centers, in addition to increased costs, data center challenges faced serious environmental pollution and more greenhouse gases. Use of renewable energy and reducing electricity costs in data centers are the important subjects for researchers around the world. Many researchers provide solutions to reduce environmental...
Lifetime-Aware Resource Allocation in Cloud Computing for Energy Optimization
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
Cloud computing is a way to increase capacity or add capabilities dynamically without investing in new infrastructure. The purpose of this project is the use of specialized algorithms for efficient energy management for cloud computing environments.One of the issues that is very important with respect to cloud computing is considering lifetime of servers or physical machines. Servers are some of the most important and critical elements of cloud computing. Server costseffect on the costs of the entire cloud computing system and the interference of serverseffects on entire system. Lifetime of each sever is dependent on a few factors, the most important of which is the number of switching...
Improving Energy Efficiency in Multi-processor Soft-Core Systems Using System-level Techniques
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
The ever increasing density and performance of FPGAs, has increased the importance and popularity of soft processors. One major research concern in this regard lays in the field of energy efficiency of the system on FPGA. This work is particularly focused on the energy efficiency of multiprocessor structures on FPGA using system level techniques. The growing gap between the speed of processors and memories can partly be compensated through memory hierarchy, i.e. caches. Since memory accesses follow a non-uniform distribution, and vary from one application to another, variable set-associative cache architectures have emerged. In this thesis, two novel cache architecture, primarily aimed at...
Managing Shared Use of an FPGA-based Accelerator among Virtual Machines
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
Using accelerators inside high speed servers can reduce execution time of applications and total power usage of the system. Sharing accelerator between virtual machines of a server decrease both cost and power, however it won’t provide the gained speedup of using dedicated accelerator for each virtual machines. Creation of an appropriate set of accelerators required for virtual machines, management of accesses to the accelerator, prioritizing and scheduling of requests and reconfiguration type of accelerator are the most important challenges that this project has been dealt with. The main objective of this project is implementing the necessary infrastructure to share an FPGA-based...
Performance Estimation of Processing Nodes in Big Data Computation
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
Today, we have witnessed many changes in computer science. Rapid and exponential growth of data volumes, increasing a variety of data structures and forms, increasing data generation ratio are some important revolutions in our digital world. Because of these changes, our traditional computing models and processing methods cannot solve new big and sophisticate problems. Big data concepts and big data processing methods come to help us for solving these problems. A lot of parallel and distributed processing platforms built for the applications execution on a huge volume of data. Apache spark and Hadoop are two powerful platforms that each has some advantage and disadvantage. With growth...
Accelerating Big Data Stream Processing by FPGA-implementation of Parts of the Topology Graph
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
In recent years, big data processing plays an important role in the era of information technology. The exponential growth of big data volume increases the need for data centers and infrastructures with more processing power. Due to dark silicon and scalability limitations in deep-submicron, the increasing trend of server performance slows down. Therefore, hardware accelerators such as FPGA and GPU are become increasingly popular for improvement of data center processing power. There are two types of big data processing based on the application: stream processing and batch processing. With the widespread use of social networks, online control systems and internet of things services, the...
Using FPGA as Accelerator for Processing Units in Big Data Stream Processing Engine
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
Distributed stream processing frameworks (DSPFs) are used for real-time processing of big data. Apache Storm is one of the most popular stream processing systems in industry today. By increasing data generation rate we need new methods to overcome processing requirements of DSPFs like Apache Storm. In this thesis we investigate the feasibility of incorporation FPGA acceleration into Apache Storm. Using FPGAs as co-processors in powerful servers can improve performance and accelerate processing of streaming data by increasing parallelism, decreasing processing time of each processing units and decreasing communication delay between these units. Our design includes a hardware part that...
Design and Implementation of an Offline Scheduling and Resource Allocating Algorithm for Distributed Big Data Stream Processing Systems
, M.Sc. Thesis Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
One of the most important categories of big data processing is stream processing. In stream processing, processing of data is performed simultaneously with the production of data. one of the most well-known frameworks used for stream processing is Apache Storm. By default, Storm uses a round-robin scheduler to allocate tasks to physical machines. This scheduler randomly performs scheduling and assignment of tasks to physical machines without considering the processing power of physical machines and processing tasks, which makes it impossible to properly utilize the processing resources. In this paper, a scheduling algorithm and resource allocation have been proposed based on the processing...
Using Data Variety in Progressive Processing of Big Data in Cloud Environment
, Ph.D. Dissertation Sharif University of Technology ; Goudarzi, Maziar (Supervisor)
Abstract
Nowdays a large number of companies are faced with Big Data processing. Due to the lack of budget or time, it may not be possible to process all the input data. Data variety is one of the main features of Big Data. Considering Data variety can help us to solve the problem of resource capacity. In this research, we focused on the impact of data variety on the performance of Big Data processing. In the first part, we offer a solution for increasing the performance of progressive Big Data processing. We provide a simple low-overhead mechanism to quickly assess the significance of each data portion, and show its effectiveness in finding the best ranking of data portions. We continue by...