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beheshti-seresht--hassan
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Modelling Nonlinear Viscoelastic Behavior of Hydrogels
, M.Sc. Thesis Sharif University of Technology ; Mohammad Navazi, Hossein (Supervisor) ; Arghavani Hadi, Jamal (Supervisor)
Abstract
In this thesis, the mechanical properties of collagen hydrogels were characterized using Finite Element method and the collagen content effect on the mechanical properties of hydrogels were investigated. Hydrogels samples with different collagen content were assessed which caused diverse mechanical behaviors. Due to the nonlinear behavior of hydrogels, using numerical methods and simulation softwars can be helpful to determine the mechanical properties of these material and save agreat deal of time. Finite Viscoelaticity theory was exploited for a UMAT Subroutine in Abaqus and an special Starin Energy Function was selected to extract the formulations. The agreement between simulation results...
Optimal Fractional PID for Thermoelectric Cooler
, M.Sc. Thesis Sharif University of Technology ; Alasty, Aria (Supervisor) ; Salarieh, Hassan (Supervisor)
Abstract
Today, energy production as well as environmental damage caused by non-renewable fuels has become one of the serious challenges of Society. Thermoelectrics are among the systems that can be used as a new source for cooling and heating production as well as electric energy production.Thermoelectrics can be divided into two categories: Cooler/thermal thermoelectrics and thermoelectric generators. Cooler/thermal thermoelectrics can be used as a source for producing cooling and heating in various applications, among its advantages are the non-use of environment-hazardous refrigerants, suitable for use in small spaces, not heavy and complicated, easy maintenance and low cost. It is also possible...
A method for ranking non-extreme efficient DMUs
, Article CIE 2014 - 44th International Conference on Computers and Industrial Engineering and IMSS 2014 - 9th International Symposium on Intelligent Manufacturing and Service Systems, Joint International Symposium on "The Social Impacts of Developments in Information, Manufacturing and Service Systems" - Proceedings ; Volume 7, Issue 2 , February , 2014 , pp. 618-622 ; ISSN: 18624480 ; Khosravi, Sh ; Sharif University of Technology
2014
Abstract
Data Envelopment Analysis (DEA) is a method to measure the efficiency of a DMU (Decision Making Unit, e.g. school, public agencies and banks). One of the ways for determining rank of DMUs is efficient score of each DMU. An interesting research issues is to discriminate between efficient DMUs. In literatures, supper efficiency is an applicable method for ranking efficient DMUs. The main drawback of this method is an inability of this method to rank non-extreme efficient DMUs. Therefore, this issue reduces the usefulness of this method. In this paper we propose a new ranking system for non-extreme efficient DMUs (Decision Making Units) based upon the omission of DMUs from reference set of the...
Simple methodology for the aerobic N-methylation of substituted anilines catalyzed by zirconium oxychloride octahydrate, ZrOCl2·8H 2O
, Article Industrial and Engineering Chemistry Research ; Volume 52, Issue 32 , 2013 , Pages 11001-11006 ; 08885885 (ISSN) ; Rezaei Seresht, E ; Jafari, F ; Rabiei, S ; Sharif University of Technology
2013
Abstract
A highly chemoselective methodology is described for the N-methylation of functionalized anilines with dimethyl carbonate (MeOCO2Me, DMC) in the presence of ZrOCl2·8H2O. Dimethyl carbonate, which usually promotes methylation at T > 120 C and eventually under inert atmosphere, was activated in the presence of zirconium oxychloride for the desired transformation at 90 C under aerobic conditions. Aminophenols showed good reactivity in this transformation and produced the corresponding N-methylanilines, as the major products, with high selectivity. Catalyst reusability study confirmed that ZrOCl2·8H2O is a recyclable catalyst and its catalytic activity was remained unchanged at least after eight...
New hybrid finite volume-thermal lattice Boltzmann method, based on multi relaxation time collision operator
, Article International Journal of Heat and Mass Transfer ; Volume 138 , 2019 , Pages 1281-1294 ; 00179310 (ISSN) ; Alizadeh Seresht, E ; Taeibi Rahni, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Hybrid FVM-LBM schemes are developed in the past few years to use capabilities of both Navier-Stokes based finite volume method (FVM) and lattice Boltzmann method (LBM) to solve macro-meso multiscale problems. In this scheme, the major task is to develop some lifting relations that reconstruct distribution functions in LBM sub-domain from macroscopic variables and their derivatives. The macroscopic variables are computed using Navier-Stokes based FVM in macroscale sub-domain, while distribution functions are computed using LBM in mesoscale sub-domain. The pioneer works in this area used the single relaxation time (SRT) version of LBM. However, it is known that the numerical stability and...
An Approach for Keeping Consistency of Models During the Evaluation of Modeling Languages
, M.Sc. Thesis Sharif University of Technology ; 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...
Analysis of Equilibrium Points in Economic Games
, M.Sc. Thesis Sharif University of Technology ; Habibi, Jafar (Supervisor)
Abstract
Nowadays economical issues are greatly taken into consideration. In this project we aim to study a problem of this area, which focuses on the subject of location allocation and pricing strategy for a good supplier. Solution evaluation is done by taking costumer demand into account. This problem has a sequential characteristic. That is players do not take their decisions at the same time. Suppliers should first decide about where and how they plan to provide their goods. On the other hand almost every economical problem have multiple players who play with or against each other. Therefore modeling this problem using Stackelberg leadership model is a natural choice. Since this problem is in the...
Sustainability Assessment of Preventive Maintenance Plans (Case Study: Slurry Seal and Thin Overlay)
, M.Sc. Thesis Sharif University of Technology ; Tabatabaee, Nader (Supervisor)
Abstract
Preventive maintenance strategies have been considered by highway agencies in order to increase pavement service life and to reduce the costs associated with pavement maintenance. Due to the increasing concern regarding promoting sustainable pavements, consideration of the environmental, economic and performance factors in devising preventive maintenance strategies is of great importance.This study contributes to developing a multicriteria decision-making tool for sustainability evaluation of pavement preventive maintenance strategies. The developed tool, PaveSAT, considers the greenhouse gas emission, net present value, and pavement performance to rank preventive maintenance schemes using...
On the nonlinear dynamic responses of FG-CNTRC beams exposed to aerothermal loads using third-order piston theory
, Article Acta Mechanica ; Volume 229, Issue 6 , 2018 , Pages 2413-2430 ; 00015970 (ISSN) ; Rabiei Beheshti, A ; Sharif University of Technology
Springer-Verlag Wien
2018
Abstract
The purpose of this study is to analyze the nonlinear dynamic responses of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) beams exposed to axial supersonic airflow in thermal environments. The dynamic model of the FG-CNTRC beam is developed with regard to the first-order shear deformation theory incorporating the von Kármán geometrical nonlinearity. The thermomechanical properties of the constituents are assumed to be temperature dependent. The third-order piston theory is adopted to estimate the nonlinear aerodynamic pressure induced by the supersonic airflow. Harmonic differential quadrature method is implemented to discretize the equations of motion in the spatial...
Scour hole influence on turbulent flow field around complex bridge piers
, Article Flow, Turbulence and Combustion ; Volume 97, Issue 2 , 2016 , Pages 451-474 ; 13866184 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
Springer Netherlands
2016
Abstract
Experimental results of detailed flow measurements using an Acoustic-Doppler Velocimeter (ADV) around a complex bridge pier (CBP) are presented. The pier consists of a column, a pile cap (PC) and a 2×4 pile group. The time-averaged velocities, turbulence intensities, and Reynolds stresses are studied and presented at different horizontal and vertical planes. Streamlines obtained from the velocity fields are used to show the complexity of the flow around the pier. It is shown that the main feature of the flow responsible for the entrainment of the bed sediments is a contracted (pressurized) flow below the PC toward the piles. A deflected flow around the PC and a strong down-flow along its...
Discussion of “Neuro-fuzzy GMDH systems based evolutionary algorithms to predict scour pile groups in clear water conditions” by M. Najafzadeh
, Article Ocean Engineering ; Volume 123 , 2016 , Pages 249-252 ; 00298018 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
The author utilized neuro-fuzzy based group method of data handling (NF-GMDH) to predict the local scour depth around pile groups under clear-water conditions. They collected the datasets from literature. To predict the local scour by using NF-GMDH, nine dimensional parameters were considered to define a functional relationship between input and output variables. The results of NF- GMDH networks were compared with that of the empirical equations. However, the collected datasets for pile group scouring, the method of implementing the empirical formula to calculate scour depth, and using the equation of Sheppard et al. (2004) suggested for single pier to predict local scouring around pile...
Designing and implementing basic sciences ontology based on concepts and relationships of relevant thesauri
, Article Iranian Journal of Information Processing Management ; Volume 30, Issue 3 , Nov , 2015 , Pages 677-696 ; 22518223 (ISSN) ; Ejei, F ; Sharif University of Technology
Iranian Research Institute for Scientific Information and Documentation
2015
Abstract
Currently, the main portion of knowledge is stored in electronic texts and documents and for transferring that knowledge effectively, we must use proper methods to gather and retrieve relevant information. Ontologies provide means to produce structured documents and use intelligent search instead of keyword search. Ontology defines the common words and concepts used to describe and represent an area of knowledge. However, developing ontologies is a time consuming and labor work. So, many ontology developers try to facilitate and speed up this process by reusing other resources. In fact, thesaurus contains semantic information and hierarchical structure that make it an appropriate resource...
Experimental study of three-dimensional flow field around a complex bridge pier
, Article Journal of Engineering Mechanics ; Volume 136, Issue 2 , 2010 , Pages 143-154 ; 07339399 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
2010
Abstract
In this paper, three-dimensional turbulent flow field around a complex bridge pier placed on a rough fixed bed is experimentally investigated. The complex pier foundation consists of a column, a pile cap, and a 2×4 pile group. All of the elements are exposed to the approaching flow. An acoustic-Doppler velocimeter was used to measure instantaneously the three components of the velocities at different horizontal and vertical planes. Profiles and contours of time-averaged velocity components, turbulent intensity components, turbulent kinetic energy, and Reynolds stresses, as well as velocity vectors are presented and discussed at different vertical and horizontal planes. The approaching...
Entanglement-assisted communication in the absence of shared reference frame
, Article Physical Review A ; Volume 99, Issue 4 , 2019 ; 24699926 (ISSN) ; Raeisi, S ; Karimipour, V ; Sharif University of Technology
American Physical Society
2019
Abstract
Alice wants to convey the value of a parameter to Bob with whom she does not share a reference frame. What physical object can she use for this task? Shall she encode this value into the angle between two physical vectors such as the angle between two spins? Can she benefit from using entanglement? We investigate these questions here and show that an entangled state of two qubits has three parameters that are invariant under changes of the reference frame. We also calculate for specific examples the average information gain for different circumstances, where one of these parameters is used for communication. We compare our result with the special case of separable states and find that...
Analysis of threshold and incipient conditions for sediment movement
, Article Coastal Engineering ; Volume 55, Issue 5 , 2008 , Pages 423-430 ; 03783839 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
2008
Abstract
Prediction of threshold conditions and incipient motion is the essential issue for the study of sediment transport. This work compares existing empirical threshold curves proposed for Shields diagram, a method based on the concept of probability of sediment movement, and an empirical method based on movability number. These methods are used to predict the incipient motion conditions for experimental runs taken from various studies. Most of the experimental data, used in this work, have not been used before in derivation of alternative formulations for Shields diagram and other methods. The empirical threshold curves based on the Shields entrainment function was the least successful at...
Anti-Icing System Simulation and Ice Acceration on Wing in Cold & Humidity Weather
, M.Sc. Thesis Sharif University of Technology ; Darbandi, Massoud (Supervisor)
Abstract
The attention to ice accretion subject and its implementation have recently become very serious in our country due to a substantial need to a further understanding of this phenomenon and improving the design and construction of anti-ice systems for the airplanes in-hand. The subject of this study is the numerical simulation of ice accretion at the surface of airplanes, which is a technical approach in aerospace engineering. In other words, this study simulates the details of ice growth at different sections of an airplane wing considering wide ranges of different affecting parameters and conditions. To achieve this, we numerically solve the governing equations for two-phase flow of air and...
Spark plasma sintering of a multilayer thermal barrier coating on Inconel 738 superalloy: Microstructural development and hot corrosion behavior
, Article Ceramics International ; Volume 42, Issue 2 , 2016 , Pages 2770-2779 ; 02728842 (ISSN) ; Javadi, A. H ; Bahrami, M ; Khodabakhshi, F ; Simchi, A ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
In the present work, spark plasma sintering (SPS) process was employed to prepare a nanostructured yttria-stabilized zirconia (8YSZ) coating on a nickel-based superalloy (INCONEL 738) with functionally graded structure. A stack layer of INCONEL 738/NiCrAlY powder/Al foil/NiCrAlY+YSZ powder/YSZ powder was SPSed in a graphite die at an applied pressure of 40 MPa under an vacuum atmosphere (8 Pa). The sintering temperature was ∼1040 °C. For comparison purpose, the air plasma spray (APS) technique was employed to prepare the thermal barrier coating (TBC). Microstructural studies by scanning electron microscopy showed that the SPSed coating was sound and free of interfacial cracks and large...
Vulnerability assessment of urban groundwater resources to nitrate: the case study of Mashhad, Iran
, Article Environmental Earth Sciences ; Volume 76, Issue 1 , 2017 ; 18666280 (ISSN) ; Ataie Ashtiani, B ; Beheshti, A ; Sharif University of Technology
Springer Verlag
2017
Abstract
Groundwater vulnerability assessment of urban areas is a challenging task in the fast trend of urbanization around the globe. This study introduces a new approach for modifying well-known parameters of common vulnerability indexes to adjust them for urban areas. The approach is independent of a specific weighting system. The aquifer of Mashhad city, contaminated by domestic wastewater, is selected as a case in this study. In order to evaluate the aquifer vulnerability due to anthropogenic activities, at first, parameters of depth to groundwater, recharge, land use, and soil are modified based on their basic concepts and their influences on contamination attenuation. Then, the modified...
Categorization of various essential datasets and methods for textual spelling detection and normalization
, Article Iranian Journal of Information Processing Management ; Volume 32, Issue 4 , 2017 , Pages 1143-1170 ; 22518223 (ISSN) ; Abdi Ghavidel, H ; Sharif University of Technology
Iranian Research Institute for Scientific Information and Documentation
2017
Abstract
One of the most primary phases of automatic text processing is spelling error detection and grapheme normalization. Storing textual documents faces several problems without passing this phase, which causes a disturbance in retrieving the documents automatically. Therefore, specialists in the fields of natural language processing and computational linguistics usually make an attempt to sample various data through presenting ideal methods and algorithms in order to reach the normalized data. Several researches have been conducted on English and some other languages, which have been followed by a certain amount of researches on Farsi too. Sometimes, these several researches have remained to be...
Development of grid resource discovery service based on semantic information
, Article SpringSim '07: Proceedings of the 2007 spring simulaiton multiconference ; Volume 1 , 2007 , Pages 141-148 ; 07359276 (ISSN) ; 1565553128 (ISBN); 9781565553125 (ISBN) ; Moshkenani, M. S ; Sharif University of Technology
2007
Abstract
Grid computing is a type of parallel and distributed system that provides the possibility of sharing, choosing and collecting the autonomous resources (such as computer, software, databases, and equipments) that are distributed geographically. Resource discovery is one of the key subjects in distributed systems and especially Grids. We should consider that Grid consists of different applications that each of them consist of different hardware and software resources, therefore recognizing these resources is important in a Grid system. Classical approaches to Grid resource discovery are either centralized or hierarchical [1] (and will maybe prove inefficient as the scale of Grid systems...