Spark plasma sintering of ultrafine YSZ reinforced Cu matrix functionally graded composite

, Article Acta Metallurgica Sinica (English Letters) ; Volume 29, Issue 12 , 2016 , Pages 1169-1176 ; 10067191 (ISSN) Mirazimi, J ; Abachi, P ; Purazrang, K ; Sharif University of Technology

Chinese Society for Metals 2016

Abstract

Copper matrix composites have received more attentions as possible candidate for thermal and electrical conductive materials to be used in electrical contact applications. In this study, five-layered Cu/YSZ (yttria-stabilized zirconia) functionally graded material (FGM) and copper matrix composite specimens containing 3 and 5 vol% YSZ particles plus pure Cu specimen were synthesized using powder metallurgy (PM) route and spark plasma sintering (SPS) consolidation process. The microstructural and some physical, mechanical features of all specimens were characterized. Microscopic examinations showed that ultrafine YSZ particles were distributed in the copper matrix almost homogeneously. An...

Microstructural characterization and dry sliding wear behavior of spark plasma sintered Cu-YSZ composites

, Article Transactions of Nonferrous Metals Society of China (English Edition) ; Volume 26, Issue 7 , 2016 , Pages 1745-1754 ; 10036326 (ISSN) Mirazimi, J ; Abachi, P ; Purazrang, K ; Sharif University of Technology

Nonferrous Metals Society of China 2016

Abstract

In the present study, yttria stabilized zirconia (YSZ) reinforced Cu matrix composite specimens were produced by spark plasma sintering (SPS). For comparison, pure Cu specimen was also produced in the same conditions. The effect of particles content on microstructure, relative density, electrical conductivity, and Vickers hardness was evaluated. The pin-on-disk test was also performed to determine dry sliding wear behavior of specimens under different wear conditions. After sliding wear tests, the worn surfaces were examined by field emission scanning electron microscopy (FE-SEM). Microstructural study showed satisfactory distribution of reinforcement particles in copper matrix. The relative...

Design and Construction of PE/W/LiF Composites as the Shield of Neutron-gamma in Mixed Fields

, M.Sc. Thesis Sharif University of Technology Mirazimi, Samaneh (Author) ; Vossoughi, Nasser (Supervisor) ; Asadi, Skandar (Co-Advisor)

Abstract

In a nuclear reaction, particles such as gamma, neutron, alpha beta, etc. May be emitted. Environment and humans could be damaged severely if these radiations are not properly shielded. One of the main goals of this project is manufacture proper shields for neutron and gamma attenuation and absorption in mixed fields, benefiting the particular properties of composites. In preliminary stage of this project, with comprehensive studies, primary materials were selected. These materials are Tungsten, Polyethylene and Lithium Fluoride selected as Gamma absorber, thermalizer and thermalized neutron absorber respectively. In the next step, weight fractions of each material and thicknesses of...

Production and Investigation of Microstructure and Some Physical and Mechanical Properties of Copper Matrix Composites Reinforced with Micro-nano Yttria Stabilized Zirconium Oxide (YSZ) Particles

, M.Sc. Thesis Sharif University of Technology Mirazimi, Jafar (Author) ; Purazarang, Kazem (Supervisor) ; Abachi, Parvin (Supervisor)

Abstract

In this study, the ultrafine-nanometric yttria stabilized zirconia (YSZ) particles were used for reinforcing of copper metal powder. To producing of bulk nanocomposite specimens, the copper powder and the proper volume percent of reinforcement powders (i.e. 2, 3 and 5) were mixed using Turbula mixer for one hour. Before the mixing of two metallic powders and ceramic nanoparticles, for separation of agglomerated zirconium oxide nanoparticles that witch leads to producing of nanocomposite specimens with satisfactorily distributed secondary phase, the ultrasonic devise with enough quantity of ethanol as neutral liquid have been used for 15 minutes. The powders mixture have been placed under...

Water film rupture in blocked oil recovery by gas injection: experimental and modeling study

, Article Chemical Engineering Science ; Volume 161 , 2017 , Pages 288-298 ; 00092509 (ISSN) Mirazimi, S ; Rostami, B ; Ghazanfari, M. H ; Khosravi, M ; Sharif University of Technology

2017

Abstract

Water shielding phenomenon generally occurs after waterflooding in water-wet rocks, and impedes direct contact between the oil and the injected gas in tertiary gas injection processes. In this work, a set of visualization experiments were performed on micromodel patterns including designed dead-end pores with a film of water on the surface of pore bodies, which is a more realistic representation of porous media. The experiments were conducted at different miscibility conditions, and the required time for water to be displaced from the throat by the swelling of oil was measured for first contact miscible (n-C5/CO2) and immiscible (n-C10/CO2) systems. In the next step, a model was proposed to...

Application of the Maxwell-Stefan theory in modeling gas diffusion experiments into isolated oil droplets by water

, Article Physics of Fluids ; Volume 34, Issue 11 , 2022 ; 10706631 (ISSN) Mirazimi, S ; Rostami, B ; Ghazanfari, M. H ; Khosravi, M ; Sharif University of Technology

American Institute of Physics Inc 2022

Abstract

We have used the Maxwell-Stefan diffusion theory to model the mass transfer between tertiary-injected gas and residual oil blocked by water, in order to predict the time required for the rupture of the water barrier due to oil swelling. We have also designed and conducted a set of visualization micromodel experiments on various pure and multicomponent oil-gas systems to measure the water rupture time in tertiary gas injection processes. The experimental results show that the initial pressure and dimensions of the system, the oil and gas composition, and the gas solubility in water control the oil swelling process. The experimentally measured rupture times are then employed to evaluate the...

The role of water film on dead-end pore walls in the enhancement of mass transfer between shielded oil and gas

, Article 79th EAGE Conference and Exhibition 2017: Energy, Technology, Sustainability - Time to Open a New Chapter, 12 June 2017 through 15 June 2017 ; 2017 ; 9789462822177 (ISBN) Mirazimi, S ; Rostami, B ; Ghazanfari, M. H ; Khosravi, M ; Saudi Aramco; Shell; Total ; Sharif University of Technology

European Association of Geoscientists and Engineers, EAGE 2017

Abstract

Water shielding happens in water-wet reservoirs after waterflooding, where water fills the throats of oil-bearing dead-end pores and prevents tertiary injected gas from direct contact with oil; however, diffusion takes place between gas and oil via dissolution of components in water, which causes the oil to gradually swell until it completely pushes away the water from the throat. None of the previous experimental and numerical studies on the water-shielded oil recovery from a single dead-end pore have considered the presence of the thin water film on the surface of water-wet rocks, whereas it considerably enhances the gas-oil mass transfer rate by extending the contact area between the oil...

Exploiting Locality Properties of Nodes for Improving Search Efficiency in P2P Networks

, M.Sc. Thesis Sharif University of Technology Hariri, Negar (Author) ; Habibi, Jafar (Supervisor)

Abstract

The Use of peer-to-peer architectures instead of traditional client-server architecture can be beneficial in many aspects such as increasing scalability of the systems, enhancing fault tolerance in critical situations, extending the system resources and various other advantages. Nowadays, many applications are based on peer-to-peer architectures and as a result, a large portion of the internet traffic is produced by these applications. This has been a motivation to many researchers to focus on reducing the amount of this traffic while satisfying the content distribution demands. One of the main problems that can result in generating large amount of traffic and also long response times for...

Automatic Extraction of Semantic Web Service Composition Patterns

, M.Sc. Thesis Sharif University of Technology Ghoroghi, Camellia (Author) ; Habibi, Jafar (Supervisor)

Abstract

In today’s competitive world، web services have become more and more prevalent and their efficient discovery and composition in order to create novel functionalities is essential for variety of applications. Due to the large number of available services، the discovery of services is a difficult and time consuming task. Existing approaches in web services discovery and composition attempt to use simple web services while ignoring the use of once composed services. Reusing frequently used composite services can considerably increase performance of the entire system. Moreover، the advent of semantic web، as an effective solution of representing information interpretable by machines and none...

An Engineering Approach to Software Modeling Language Development

, Ph.D. Dissertation Sharif University of Technology Kamandi, Ali (Author) ; Habibi, Jafar (Supervisor)

Abstract

Nowadays, the essentiality of appropriate modeling languages has become evident, and with the introduction of new concepts such as domain-specific languages, the need for systematic research on designing and engineering new modeling languages has increased significantly. Several modeling languages have been developed and employed over the years, but the area of modeling languages still suffers from the lack of a proper framework: There is a strong need for an engineering framework that specifies the detailed steps of language development, the input and output artifacts of each step, the techniques applicable to each step, and quantifiable methods for quality measurement. From a unified point...

Distributed Data Mining in Peer-to-Peer Systems

, Ph.D. Dissertation Sharif University of Technology Mashayekhi, Hoda (Author) ; Habibi, Jafar (Supervisor)

Abstract

Peer-to-peer (P2P) computing is a popular distributed computing paradigm for many applications which in-volve exchange of information among a large number of peers. In such applications, large amount of data is distributed among multiple dispersed sources. Therefore, data analysis is challenging due to processing, storage and transmission costs. Moreover, the data rarely remains static and frequent data changes, quickly out date previously extracted data mining models. Distributed data mining deals with the problem of data analysis in environments with distributed data and computing resources. In this dissertation, we explore distributed data mining in different structures of P2P systems. In...

An Architecture Description Language for Software Product Line

, M.Sc. Thesis Sharif University of Technology Tanhaei, Mohammad (Author) ; Habibi, Jafar (Supervisor)

Abstract

Software Product Line is known as a process of developing family of the software together. The methods of building a software product line is trying to capture commonality and variety of this family of software and form a product line based on them. Commonality of this family of the software allows us reuse in every aspect of the development of software. Nowadays, software architecture as a one of the most important aspect of software engineering, plays major role in specifying the tasks and clearing the relationship between people. It can divide large and complex system to some sub-system and overcome complexity of the system. Software architecture forms a basis for communication among...

Designing a Model-Based Process and Architecture for Partial Automation of Software Development

, M.Sc. Thesis Sharif University of Technology Jalal, Ali (Author) ; Habibi, Jafar (Supervisor)

Abstract

Automation of the software development process is the software engineers' final goal, but with the current facilities and knowledge in software engineering, it is not possible to automatically generate the whole software. Usually all the software in a specific domain contain common behaviors, which by careful exploration of these common behaviors and automation of code generation in these sections, the cost and time of projects' execution can be reduced. According to Model Driven Development (MDD), the first step in software development is creating appropriate models. For creating models, metamodel is required; therefore, we need to create a specific motamodel for the chosen domain or use...

Towards a Mechanism to Design Software Product Line Architecture Based on Heterogeneous Styles

, M.Sc. Thesis Sharif University of Technology Amirjan, Elahe (Author) ; Habibi, Jafar (Supervisor)

Abstract

One of approaches in software architecture design is using architecture styles or patterns. This approach is a suitable way for satisfying functional and nonfunctional requirements and also is cost effective. It is shown that this approach improves effectively quality of software systems. Whereas, choosing a suitability architecture style for complex designs depends on many factors and often one style cannot meet all the requirements, therefore, use of heterogeneous styles can be useful. Also, in software product line architecture design, we must combine different kinds of architectural styles to cover the problem domain and achieve better performance. Correct and accurate choice of...

Model Selection for Complex Network Generation

, M.Sc. Thesis Sharif University of Technology Motallebi, Sadegh (Author) ; Habibi, Jafar (Supervisor)

Abstract

Nowadays, there exist many real networks with distinctive features in comparison with random networks. Social networks, collaboration networks, citation networks, protein networks and communication networks are some example of complex network classes. Nowadays these networks are widespread and have many applications and the study of complex networks is an important research area. In many applications, the “synthetic networks generation” is one of the first levels of complex networks analysis. This level has many applications such as simulation and extrapolation. Many generative models are proposed for complex network modeling in recent years. By the use of these models, synthetic networks...

Using AHP Method to Evaluate Architecture Style Designs

, M.Sc. Thesis Sharif University of Technology Akhoddad, Zahra (Author) ; Habibi, Jafar (Supervisor)

Abstract

Due to the increase in size and complexity of software systems, choosing suitable software architecture is a fundamental issue. One of the most effective ways for designing and valuating software architectures is to adopt architectural styles. An architectural style is an approach for reaping the benefits of similarities that exist between various architectures. Adoption of architectural styles in the design process of a software system assures the employment of strength points of specifications that belong to each architectural style. However, selecting a suitable architectural style depends on different criteria. Therefore it makes the ...

An Approach for Keeping Consistency of Models During the Evaluation of Modeling Languages

, M.Sc. Thesis Sharif University of Technology Beheshti, Behzad (Author) ; Habibi, Jafar (Supervisor)

Abstract

The development of a complex software needs an abstraction mechanism which is called Model Driven Engineering mechanism. In order to have a successful model based process, we need an appropriate tool such as version control systems to support our model-based process. On the other hand, developers need a mechanism to synchronize them with VCS systems. One of the concerns in modeling languages is the compatibility and the consistency of the models and modeling languages during their evaluation. the focus of the former researches was mostly on the consistency of the models during their evaluation, and to this end, lots of approaches have been proposed for keeping the consistency of the models...

Real-Time Traffic Flow Forecasting and Travel Time Prediction

, M.Sc. Thesis Sharif University of Technology Mahini, Mohammad (Author) ; Habibi, Jafar (Supervisor)

Abstract

There has been great progress in Intelligent Transportation Systems (ITS) during the past decade. It is often difficult to manage vehicle traffic systems due to high variations and complexity. Intelligent Transportation Systems try to devise more efficient and more reliable solutions for vehicle traffic systems. Many ITS applications rely on short-term predictions of traffic state and it is crucial to provide reliable estimates of the traffic state in near future.Providing an accurate estimate of transportation time in a specific piece of street is a key task in Intelligent Traffic Systems (ITS). This estimate can be either for the moment or a future prediction. A practical ITS must be...

Modeling and Simulation of the Behavior of Cancer Cells, A Multi-agent Approach

, M.Sc. Thesis Sharif University of Technology Fazli, Rasol (Author) ; Habibi, Jafar (Supervisor)

Abstract

Cancer is a complicated disease. So, cancer treatment can not be possible without understanding its complex behavior. Each of cells do inner operations spontaneously and have interactions on external environment. This feature of cells has caused to model their behaviors using multi-agents and considering each cell as an intelligent agent. Using this approach, a novel multi-scale agent-based model known as basic model has been introduced. Furthermore, two signaling pathways have been added to this model. For simulation, a new agent-based modeling framework has been proposed. After that, learning has been involved, for considering drug effects. Finally, by means of this model we can predict...

An Efficient Model For Considering the Effects Of Drug On Cancer Cells

, M.Sc. Thesis Sharif University of Technology Nikahd, Mojtaba (Author) ; Habibi, Jafar (Supervisor)

Abstract

The development of technologies and some defects in medicine caused to emerge a new approach called precision medicine. Unlike the traditional medicine, medical experts do best treatment for each patient based on his genetic characteristics in this approach. Predicting drug response on cancer cell lines is one of the most vital challenges in this area. Various approaches have been proposed to construct predicting models while the substantial distinctions between resistant and sensitive cell lines had been neglected in them. Here, we propose a new approach for constructing the predictive model. In our approach, we utilized the distinctions between sensitive and resistant cell lines and also...