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    Using Automata of Records as the Semantics of BIP Coordination Model

    , M.Sc. Thesis Sharif University of Technology Mirahmadi, Mitra (Author) ; Izadi, Mohammad (Supervisor)
    Abstract
    In component-based design, each system consists of a set of heterogeneous components that are in interaction with each other. In this approach of design, computation is executed by the components, and their interactions are considered individually. BIP and Reo are coordination languages implemented in component-based modeling of systems. The BIP framework has a layered structure to separate interactions from the calculations. There are several approachesfor the formal definition of BIP layers. There are also semantics for BIP, based on two data-based and data-agnostic approaches. On the other hand, automata of records of a model is an operational semantics for Reo coordination language, one... 

    Calculation of stress intensity factor for functionally graded cylinders with two radial cracks using the weight function method

    , Article Theoretical and Applied Fracture Mechanics ; Volume 85 , 2016 , Pages 447-456 ; 01678442 (ISSN) Mirahmadi, H ; Azimi, M ; Mirjavadi, S. S ; Sharif University of Technology
    Elsevier B.V  2016
    Abstract
    In this study, obtaining stress intensity factors (SIFs) for functionally graded cylinders with two internal radial cracks using the weight function method has been discussed. For this purpose, reference SIFs are calculated from the results of finite element analysis, using a modified domain of the J integral. Subsequently, SIFs have been calculated for different combinations of cylinder geometry, crack depth, and material gradation by implementing the weight function method and it is shown that the results are consistent with corresponding results obtained from finite element analysis. Moreover, the effects of variation in the elastic modulus ratio on SIFs have been investigated. © 2016... 

    Effect of controlled hot rolling parameters on microstructure of a nb-microalloyed steel sheet

    , Article AIP Conference Proceedings, 24 October 2010 through 27 October 2010, Paris ; Volume 1315 , 2010 , Pages 69-74 ; 0094243X (ISSN) ; 9780735408715 (ISBN) Mirahmadi Khaki, D ; Abedi, A ; Oxford; Transvalor ; Sharif University of Technology
    2010
    Abstract
    The design of controlled rolling process of microalloyed steel sheets is affected by several factors. In this investigation, effect of the reheating, finishing and coiling temperatures of rolling, which are considered as the most effective parameters on microstructure of hot rolled products has been studied. For this purpose, seven different reheating temperatures between 1000 to 1300°C with 50°C increments, three different finishing temperatures of 950, 900 and 850°C below the non-recrystallization temperature and one temperature of 800°C in the inter critical range and four different coiling temperatures of 550, 600, 650 and 700°C were chosen. By soaking the specimens in furnace, the grain... 

    Effect of finishing temperature on mechanical properties of a Nb-microalloyed steel sheet

    , Article Advanced Materials Research, 17 September 2010 through 19 September 2010 ; Volume 129-131 , 2010 , Pages 1022-1028 ; 10226680 (ISSN) ; 9780878492435 (ISBN) Mirahmadi Khaki, D ; Akbarzadeh, A ; Abedi, A ; Sharif University of Technology
    2010
    Abstract
    Thermo mechanical processing and controlled rolling of microalloyed steel sheets are affected by several factors. In this investigation, finishing temperature of rolling which is considered as the most effective parameters on the final mechanical properties of hot rolled products has been studied. For this purpose, three different finishing temperatures of 950, 900 and 850 °C below the non-recrystallization temperature and one temperature of 800 °C in the intercritical range were chosen. It is observed that decreasing the finishing temperature causes increase of strength and decrease of total elongation. This is accompanied by more grain refinement of microstructure and the morphology was... 

    Investigation of hydrogen sensing properties and aging effects of Schottky like Pd/porous Si

    , Article Journal of Sensors and Actuators B: Chemical ; Volume 146, Issue 1 , 8 April , 2010 , PP. 53–60 Razi, F. (Fatemeh) ; Iraji Zad, A. (Azam) ; Rahimi, F. (Fereshteh) ; Sharif University of Technology
    2010
    Abstract
    We prepared porous silicon samples coated by continuous palladium layer in electroless process. Scanning electron microscopy (SEM) showed cauliflower-shape Pd clusters on the surface. I–V curves of Schottky like Pd/porous Si samples were measured in air and in hydrogen. These measurements showed a metal–interface–semiconductor configuration rather than an ideal Schottky diode. Variations of the electrical current in the presence of diluted hydrogen at room temperature revealed that the samples can sense hydrogen in a wide range of concentration (100–40,000 ppm) without any saturation behavior. Hydrogen sensing properties of these samples were investigated at room temperature for a duration... 

    Effect of different lubricant on microstructure of second cold rolled silicon steel used in transformer core

    , Article Proceedings of the 10th International Conference on Steel Rolling, 15 September 2010 through 17 September 2010, Beijing ; 2010 ; 9787502453596 (ISBN) Eftekhari, S. A ; Akbarzade, A ; Mirahmadi Khaki, D ; Aminnejad, F ; Sharif University of Technology
    2010
    Abstract
    One of the important parts of each transformer is core. It is made from multilayer silicon steel sheets. Silicon steel has high magnetic permission, high electrical resistance and minimum hysterics loss. In different metal forming process, lubrication is done for reducing friction effects. In this research, effect of 3 different type lubricants, mineral material (castor oil), organic material (glycerol), and semi organic material (paraffin) with and without additive (graphite) is investigated. Also, effect of 2 industrial lubricants (suds and motor oil) is compromised with above lubricants. Results show the best lubricant for second cold rolling of silicon steel is semi organic (paraffin)... 

    Optimized Utilization of Electric Vehicles based on Cost Analysis- the point of view of Energy Policy

    , M.Sc. Thesis Sharif University of Technology Mirahmadi, Fereshteh (Author) ; Fotuhi Firouzabad, Mahmud (Supervisor) ; Rajabi Qahnuyeh, Abbas ($item.subfieldsMap.e)
    Abstract
    This thesis represents a comprehensive view of electric vehicles from the macroeconomic policy in the energy sector perspective. In fact, in this thesis all the efficient factors in the presence of electric vehicles in the transport sector have been completely proceed. Environmental, economic, social and political factors, power grids and infrastructure are considered as the impressive factors. In order to check all factors comprehensively, Systems thinking based on dynamic system method is used. The causal relationships between all the variables which are involved in the presence of electric vehicles and related models to this thesis are simulated in VENSIM software. To investigate this... 

    Simulation of the Effects of Nanofluids on the Thermal Performance of a Heat Pipe

    , M.Sc. Thesis Sharif University of Technology Mirahmadi, Hamid Reza (Author) ; Moosavi, Ali (Supervisor) ; Kazemzadeh Hannani, Siamak (Co-Advisor)
    Abstract
    In terms of thermodynamics and heat transfer, heat pipes such as closed two-phase thermosyphon are of great importance in saving energy. In this study, a computational fluid dynamics model for simulation of a thermosyphon heat pipe with two-phase flow including phase change heat transfer was developed. The study has mainly focused on the effects of volume concentrations of Nanoparticles and the operating temperature on the heat transfer performance of the thermosyphon. The analysis was performed to compare heat transfer performance between a solid copper tube and a thermosyphon heat pipe which contained deionized water and graphene oxide(GO)/water Nanofluid as its working fluids. Based on a...