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    Kinetics formation of bimetallic nanoalloys at different simulation times

    , Article Journal of Molecular Liquids ; Volume 240 , 2017 , Pages 468-475 ; 01677322 (ISSN) Akbarzadeh, H ; Taherkhani, F ; Mehrjouei, E ; Masoumi, A ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    MD simulations were used for investigation on the kinetic formation of Ni-Pd nanoalloys at different simulation times. We have examined excess energies and bond order parameters for initial gas phase compositions including pure Ni, and Pd, and also Ni0.2Pd0.8, Ni0.4Pd0.6, Ni0.6Pd0.4, Ni0.8Pd0.2 concentrations. Excess energies for created Ni-Pd nanoalloys exhibit more instabilities for larger nanoparticles. Also, bond order results demonstrate amorphous structures for all of created nanoclusters. Moreover, number of formed clusters for pure Ni at 5 ns is more than pure Pd nanoclusters and number of formed clusters decreases when Pd is doped in pure Ni nanocluster. © 2017 Elsevier B.V  

    Mathematical modeling of CSF pulsatile hydrodynamics based on fluid-solid interaction

    , Article IEEE Transactions on Biomedical Engineering ; Volume 57, Issue 6 , 2010 , Pages 1255-1263 ; 00189294 (ISSN) Masoumi, N ; Bastani, D ; Najarian, S ; Ganji, F ; Farmanzad, F ; Seddighi, A. S ; Sharif University of Technology
    2010
    Abstract
    Intracranial pressure (ICP) is derived from cerebral blood pressure and cerebrospinal fluid (CSF) circulatory dynamics and can be affected in the course of many diseases. Computer analysis of the ICP time pattern plays a crucial role in the diagnosis and treatment of those diseases. This study proposes the application of Linninger et al.s [IEEE Trans. Biomed. Eng. , vol. 52, no. 4, pp. 557565, Apr. 2005] fluidsolid interaction model of CSF hydrodynamic in ventricular system based on our clinical data from a group of patients with brain parenchyma tumor. The clinical experiments include the arterial blood pressure (ABP), venous blood pressure, and ICP in the subarachnoid space (SAS). These... 

    Influence of Floor Diaphragm on Seismic Response of RC Structures

    , M.Sc. Thesis Sharif University of Technology Masoumi, Hassan (Author) ; Khaloo, Alireza (Supervisor)
    Abstract
    Modeling is one of the most important steps in analysis and design of structures. Most of the time behavior of floor diaphragms is assumed completely rigid in their plane in order to simplicity in practical design. Although this assumption leads to acceptable results in analysis and design of conventional buildings, erroneous results may assess in some particular buildings—for instance narrow buildings with stiff end walls. Accordingly, behavior of these buildings in future earthquakes opposes those were predicted in design phase, and they are so vulnerable since in-plane deflection of floor diaphragms are striking which cannot be ignored. This thesis investigates the significance of... 

    A Finance-Inventory Modeling in Supply Chain with Delay in Payments

    , M.Sc. Thesis Sharif University of Technology Masoumi, Mohammad (Author) ; Hajji, Alireza (Supervisor)
    Abstract
    This thesis deals with the financial risk management and coordination of supply chain members. To investigate this issue, two echelon supply chain consisting of one manufacturer and one retailer with a newsvendor inventory policy for a period is considered. The mathematical modeling has been used to find the exact answer. MATLAB software for solving and scenario generation is used for the analysis. In the proposed method, financial risk management, partial trade credit policy, coordination of supply chain members and cash discount for retailers, have been considered. According to the proposed method, the manufacturer can determine immediate payment at the start of the trade credit period... 

    Acidizing Operation Design for Oil Fields by Use of Neural Network Method

    , M.Sc. Thesis Sharif University of Technology Masoumi, Abdolkhalegh (Author) ; Goodarznia, Iraj (Supervisor)
    Abstract
    The acidizing operations have significant impact on productivity and production of oil and gas wells, so that wells having shell or regional damage are good candidates for well stimulation operations which could result in significant increase for efficiency or injectivity. Generally, the neural networks are nonlinear learning mathematical systems. In this project consists, At first, wellhead data of acidizing operation are collected in two Gachsaran oil field (38 wells) and Nar and Kangan gas field (35 wells). Generally, the neural networks are nonlinear learning mathematical systems. In the neural Network by using two algorithms, back propagation algorithm and Quick Propagation algorithm... 

    Failure analysis of a gas turbine compressor in a thermal power plant

    , Article Journal of Failure Analysis and Prevention ; Volume 13, Issue 3 , 2013 , Pages 313-319 ; 15477029 (ISSN) Masoumi Khalil Abad, E ; Farrahi, G. H ; Masoumi Khalil Abad, M ; Zare, A. A ; Parsa, S ; Sharif University of Technology
    2013
    Abstract
    This study presents the results of failure analysis of a 28 MW gas turbine at the Rei electrical power plant. The gas turbine failed during the shutdown period and near its second natural frequency at 4200 rpm. Initial inspections revealed that the compressor disk of stage 15 was fractured, and all of the stationary and rotary blades of stages 14-18 of the compressor had been detached or broken from the dovetail region of the disks. The fracture roots were investigated by performing finite element modeling and fractography analysis. It was shown that a crack was initiated from the disk edge on its interface with the rotor shaft and was propagated under cyclic loading. As a result of the... 

    Object-oriented design for system identification and its application in chemical engineering industries

    , Article International Journal of Modelling and Simulation ; Volume 33, Issue 1 , 2013 , Pages 33-39 ; 02286203 (ISSN) Masoumi, S ; Boozarjomehry, R. B ; Sharif University of Technology
    2013
    Abstract
    Application of advanced process control methods in a chemical plant requires a model which represents the transient behaviour of the plant. However, only a few plant-wide identification methods have been proposed for chemical processes. In this paper, an objectoriented process identifier (OPI) framework has been introduced for plant-wide identification to show how using object-oriented design can provide a general plant-wide modelling framework for various systems including chemical processes. The interactions between units are considered in plant-wide identification methods. As a result, the obtained models can predict the system behaviour in new operating conditions better than those... 

    Changing the Sound Horizon in Early Universe to Reconcile the Hubble Tension and Cosmological Large Scale Structure Observations

    , M.Sc. Thesis Sharif University of Technology Khalaj Masoumi, Yasaman (Author) ; Baghram, Shant (Supervisor)
    Abstract
    The Standard Model ΛCDM which includes cold dark matter and cosmological constant components provides a good fit to a large span of cosmological data and large scale structures. Recent results of local measurements of Hubble constant rely on observations of type 1A supernovae have shown 4σ tension comparing H0 to the value inferred from cosmic microwave background observations assuming ΛCDM. The Hubble parameter appears in the cosmic microwave background as one of the standard cosmological model parameters. If these observations are not the result of statistical or systematic error, They could represent new physics beyond the standard ΛCDM cosmological model. The purpose of this thesis is to... 

    2D computational fluid dynamic modeling of human ventricle system based on fluid-solid interaction and pulsatile flow

    , Article Basic and Clinical Neuroscience ; Volume 4, Issue 1 , 2013 , Pages 64-75 ; 2008126X (ISSN) Masoumi, N ; Framanzad, F ; Zamanian, B ; Seddighi, A. S ; Moosavi, M. H ; Najarian, S ; Bastani, D ; Sharif University of Technology
    2013
    Abstract
    Many diseases are related to cerebrospinal fluid (CSF) hydrodynamics. Therefore, understanding the hydrodynamics of CSF flow and intracranial pressure is helpful for obtaining deeper knowledge of pathological processes and providing better treatments. Furthermore, engineering a reliable computational method is promising approach for fabricating in vitro models which is essential for inventing generic medicines. A Fluid-Solid Interaction (FSI)model was constructed to simulate CSF flow. An important problem in modeling the CSF flow is the diastolic back flow. In this article, using both rigid and flexible conditions for ventricular system allowed us to evaluate the effect of surrounding brain... 

    Modeling, Simulation and Characterization of Blood Treatment and Filtration Process in Home Hemodialysis Machines

    , M.Sc. Thesis Sharif University of Technology Masoumi, Arezou (Author) ; Saeedi, Mohammad Saeed (Supervisor)
    Abstract
    Dialysis which is an imperfect but most common treatment option for renal failure is divided into two main types:"peritoneal dialysis" and "hemodialysis". Peritoneal dialysis uses a fluid that is placed into the patient's stomach cavity through a special plastic tube to remove excess waste products and fluid from the body.Hemodialysis uses a special type of filter to remove excess waste products and water from the body and is divided to two groups :Clinical and Home.During hemodialysis, blood passes from the patient's body through a filter in the dialysis machine. In this Study first the basic aspect of renal failure and principle of dialysis process are described.Then information about... 

    Modeling and control of a naphtha thermal cracking pilot plant

    , Article Industrial and Engineering Chemistry Research ; Volume 45, Issue 10 , 2006 , Pages 3574-3582 ; 08885885 (ISSN) Masoumi, M ; Shahrokhi, M ; Sadrameli, M ; Towfighi, J ; Sharif University of Technology
    2006
    Abstract
    A computer-controlled pilot plant has been constructed to study the dynamical behavior and control of the thermal cracking furnace. The governing equations that describe the furnace dynamics are presented, and, based on these equations and a kinetic model, software that simulates the steady-state behavior of the system has been developed. The furnace is divided into eight zones that can be heated independently, and, therefore, any desired temperature profile can be applied. The variables to be measured are the furnace zone temperature, coil outlet temperature (COT), and product yield. Two different control strategies (namely, COT control and furnace wall temperature control) are applied... 

    Tribological characterization of electroless Ni-10% P coatings at elevated test temperature under dry conditions

    , Article International Journal of Advanced Manufacturing Technology ; Volume 62, Issue 9-12 , October , 2012 , Pages 1063-1070 ; 02683768 (ISSN) Masoumi, F ; Ghasemi, H. R ; Ziaei, A. A ; Shahriari, D ; Sharif University of Technology
    Springer  2012
    Abstract
    An experimental study of wear characteristics of electroless Ni-10% P coating sliding against hard AISI 52100 steel pin is investigated. Experiments are carried out at room and 550°C temperatures. Heat treatment effects on tribological behavior of this coating are studied. The wear surface and the microstructure of the coatings are analyzed using optical microscopy, scanning electron microscopy, energy dispersion analysis X-ray, and microhardness testing equipment. It is observed that the forming of continuous oxide film on contacting surfaces of pin and disk improves wear resistance and decreases friction coefficient of the Ni-10% P coating. The results indicate that the wear resistance of... 

    New approach to VLSI buffer modeling, considering overshooting effect

    , Article IEEE Transactions on Very Large Scale Integration (VLSI) Systems ; Volume 21, Issue 8 , August , 2013 , Pages 1568-1572 ; 10638210 (ISSN) Mehri, M ; Kouhani, M. H. M ; Masoumi, N ; Sarvari, R ; Sharif University of Technology
    2013
    Abstract
    In this brief, we use the alpha power law model for MOS devices to reach a more accurate modeling of CMOS buffers in very deep submicrometer technologies. We derive alpha model parameters of a CMOS buffer for 90-, 65-, and 45-nm technologies using HSPICE simulations. By analytical efforts we find the output resistance of a minimum-size buffer and compare it with those extracted from HSPICE simulations. We propose a new model for the output resistance of a given-size buffer in any technology, which demonstrates 3% error on average as opposed to the conventional model. Also a new buffer resistance is proposed analytically and numerically to calculate the crosstalk for interconnect analysis... 

    Critique and Survey of Various Formulation of Multiverse Theory

    , Ph.D. Dissertation Sharif University of Technology Masoumi, Saeed (Author) ; Golshani, Mehdi (Supervisor) ; Sheikh Jabbari, Mohammad Mehdi (Supervisor)
    Abstract
    Multiverse scenario has been recently addressed by physicists and they have found it useful in many areas of physics. In this dissertation, I have treated some issues about multiverse such as the kinds of multiverses, the arguments for or against multiverse, areas in which multiverse is introduced, etc. This dissertation has six chapters and an appendix. In the chapter one, some classifications of multiverse is introduced, and also some definitions of the concept of a world is presented. Then, my classification and definition of a multiverse and a world is introduced. In the chapter two, the concept of possible worlds in philosophy and its relationship with multiverse hypothesis is examined.... 

    Scattering from Objects in Presence of Rough Surfaces

    , M.Sc. Thesis Sharif University of Technology Masoumi, Amir Reza (Author) ; Shishegar, Amir Ahmad (Supervisor) ; Rejaei, Behzad (Co-Advisor)
    Abstract
    Electromagnetic wave scattering from objects is one of the most important problems in applied electromagnetics. Usually the electromagnetic scattering characteristic from an object is analyzed with the assumption that the object is in free space. If the object is not near other objects or surfaces this is acceptable. However if the object is near other objects or surfaces then the interactions between the scattered wave from the object and surroundings can significantly alter the scattering characteristic from the object.In this thesis we have proposed a method for the analysis of electromagnetic scattering from an object in the presence of rough surfaces. This method is based on the... 

    Failure analysis of a gas turbine compressor

    , Article Engineering Failure Analysis ; Volume 18, Issue 1 , 2011 , Pages 474-484 ; 13506307 (ISSN) Farrahi, G. H ; Tirehdast, M ; Masoumi Khalil Abad, E ; Parsa, S ; Motakefpoor, M ; Sharif University of Technology
    2011
    Abstract
    During the shut down period, a 32. MW gas turbine experienced a severe failure accompanied by a loud noise near its second natural frequency at 4200. rpm. After opening the turbine casing, it was revealed that the disks of stages 16 and 17 of the compressor had been fractured and all of the stationary and rotary blades of stages 14-18 of the compressor had been detached from the dovetail region of the disks. The degree of damage was such that repairing the compressor was not economical, and thus, the compressor was no longer able to be used. Diagnostic work was carried out using different finite element models and fractography analysis. Analysis showed that multiple cracks had been initiated... 

    Investigation of the Photonic Scattering Error in Radiography of Pipes and its Evaluation by Mote- carlo Simulation

    , M.Sc. Thesis Sharif University of Technology Masoumi Kolvanaq, Hojjat (Author) ; Vossoughi, Nasser (Supervisor) ; Movafeghi, Amir (Co-Advisor) ; Kermani, Abotaleb (Co-Advisor)
    Abstract
    Non-destructive testing method is for detect specimen flaws such as (crack, porosity, impure, welding defects, corrosion etc.) without destruction the specimen under inspection. Particular characteristic of radiography is an image product from specimen inside under testing where help to identity and better comprehend at flaw nature. Photon scattering is one of important factor to reduce image quality and signal to noise ratio. Scattered photons can due toexistent ingredient in the radiography environment and curvature of material transmission pipe where cause the disorder creation in the radiography images. In this research, pipe radiography simulated using the TIC and TIR radiography... 

    Effect of heating profile on desorption curve in temperature programmed desorption analysis: Case study of acid sites distribution of SAPO-34

    , Article Journal of Porous Materials ; Volume 16, Issue 5 , 2009 , Pages 599-603 ; 13802224 (ISSN) Izadbakhsh, A ; Farhadi, F ; Khorasheh, F ; Yan, Z. F ; Sharif University of Technology
    2009
    Abstract
    Comparison of the traditional linear heating method of TPD with an original stepwise heating scheme was reported for the first time. Stepwise heating TPD was carried out by keeping the temperature constant as soon as ammonia desorption signal rises until the signal returns to the baseline. More ammonia desorption peaks on a SAPO-34 catalyst were identified using TPD with stepwise heating. The effect of temperature ramp on desorption peak broadening in TPD curve was also addressed. The more distinct ammonia desorption peaks in stepwise TPD indicates that ammonia adsorbs in about five or six different ways on SAPO-34, and attribution of different adsorptions may be explained considering some... 

    Iran in transition

    , Article The Lancet ; Volume 393, Issue 10184 , 2019 , Pages 1984-2005 ; 01406736 (ISSN) Danaei, G ; Farzadfar, F ; Kelishadi, R ; Rashidian, A ; Rouhani, O. M ; Ahmadnia, S ; Ahmadvand, A ; Arabi, M ; Ardalan, A ; Arhami, M ; Azizi, M. H ; Bahadori, M ; Baumgartner, J ; Beheshtian, A ; Djalalinia, S ; Doshmangir, L ; Haghdoost, A. A ; Haghshenas, R ; Hosseinpoor, A. R ; Islami, F ; Kamangar, F ; Khalili, D ; Madani, K ; Masoumi Asl, H ; Mazyaki, A ; Mirchi, A ; Moradi, E ; Nayernouri, T ; Niemeier, D ; Houshang Omidvari, A ; Peykari, N ; Pishgar, F ; Qorbani, M ; Rahimi, K ; Rahimi Movaghar, A ; Ramezani Tehrani, F ; Rezaei, N ; Shahraz, S ; Takian, A ; Tootee, A ; Ezzati, M ; Jamshidi, H. R ; Larijani, B ; Majdzadeh, R ; Malekzadeh, R ; Sharif University of Technology
    Lancet Publishing Group  2019
    Abstract
    Being the second-largest country in the Middle East, Iran has a long history of civilisation during which several dynasties have been overthrown and established and health-related structures have been reorganised. Iran has had the replacement of traditional practices with modern medical treatments, emergence of multiple pioneer scientists and physicians with great contributions to the advancement of science, environmental and ecological changes in addition to large-scale natural disasters, epidemics of multiple communicable diseases, and the shift towards non-communicable diseases in recent decades. Given the lessons learnt from political instabilities in the past centuries and the... 

    Theoretical and experimental study of cascade solar stills

    , Article Solar Energy ; Volume 90 , April , 2013 , Pages 205-211 ; 0038092X (ISSN) Ziabari, F. B ; Sharak, A. Z ; Moghadam, H ; Tabrizi, F. F ; Sharif University of Technology
    2013
    Abstract
    Most part of Iran is dominated by arid and semi-arid areas due to low annual rainfall. The need for production of fresh water from brackish water is considerably high, especially in dry regions. In this study 1 month daily-based experimental data from a solar still site has been reported. The technical and operational problems of this site which finally contributed to the total cease of the site are described. Then a detailed analysis is investigated on progress of a prototype which constructed in order to solve the site's problems. The results of 1 month of experimental data of the final design showed that the last prototype could be used to solve the current problems of the site. The...