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namdar-ayoubi--arsha
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The Effect of Political Power and Political Action on the Evolution of Knowledge
, M.Sc. Thesis Sharif University of Technology ; Taheri Khorramabadi, Ali (Supervisor)
Abstract
Knowledge was traditionally understood as a one-sided foundation for all political action and, consequently, for political power. Since the late nineteenth century, however, it has been argued that political power and action also influence knowledge—and it was even suggested that power is, in fact, the sole factor shaping knowledge. Prominent advocates of this idea, such as Michel Foucault and Friedrich Nietzsche—whose thoughts profoundly influenced Foucault—employed the method of genealogy to examine historical case studies in an attempt to substantiate this claim. Yet, a critical examination of their arguments reveals that genealogy cannot support such a universal assertion. Hence, it is...
Kinetics of swelling of cylindrical functionally graded temperature-responsive hydrogels
, Article Journal of Computational Applied Mechanics ; Volume 51, Issue 2 , December , 2020 , Pages 464-471 ; Sharif University of Technology
University of Tehran
2020
Abstract
Cylindrical hydrogels have a wide variety of applications in microfluidics; for example, they serve as micro-valves, micro-mixers, and micro-lenses. The main advantages of them can be mentioned as their autonomous functionality due to their responses to environmental stimuli and simple geometry. Furthermore, functionally graded hydrogels have recently found applications in hydrogel actuators. Therefore, in this work, the kinetics of swelling, shrinking, and force generation of cylindrical functionally graded temperature-responsive hydrogels are investigated. Kinetics of cylindrical structure is investigated analytically by developing a mathematical model based on available constitutive...
Electrochemical Fabrication and Analysis of Compositionally Graded Platinum-Cobalt Coatings
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
The high production costs of pure platinum electrodes, considered the gold standard for hydrogen evolution reactions, have made the development of compositionally graded coatings a notable solution. This study focuses on the electrochemical fabrication of compositionally graded Co-Pt coatings using the potential step method, with steps at -900 mV, -645 mV, and -450 mV, each applied for 450 s. To optimize the electrolyte bath, two separate baths containing cobalt (II) sulfamate and hexachloroplatinic acid were examined: one with 0.016 M Co²⁺ and another with 10 mM Pt⁴⁺, in the presence of boric acid and sodium saccharin. The baths underwent electrochemical tests, including LSV, CV, and...
Kinetics of swelling of cylindrical temperature-responsive hydrogel: a semi-analytical study
, Article International Journal of Applied Mechanics ; Volume 12, Issue 8 , 2020 ; Mazaheri, H ; Sharif University of Technology
World Scientific
2020
Abstract
Cylindrical hydrogels have a wide variety of applications, especially in microfluidics as micro-valves, micro-mixers, and micro-lenses. Main advantages of them can be mentioned as their simple geometry and autonomous functionality due to their responses to the environmental stimuli. In current research, kinetics of swelling, shrinking and force generation of cylindrical temperature-responsive hydrogels have been investigated analytically. According to this, models of fluid permeation and large deformation of the hydrogels were considered and an analytical solution was performed. In order to study the behavior of the cylindrical hydrogels, the temperature is changed between higher and lower...
Liquefaction-induced settlement of shallow foundations on two-layered subsoil strata
, Article Soil Dynamics and Earthquake Engineering ; Volume 94 , 2017 , Pages 35-46 ; 02677261 (ISSN) ; Pak, A ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
Geotechnical design codes have been shifted from classical limit equilibrium analysis toward the performance-based procedures. In foundation design, settlement is the most representative parameter for its performance. Settlement of shallow foundations subjected to earthquake loading and its consequences is one of the most outstanding issues which should be considered in designing different structures. In this study, settlement of shallow footing on two-layered subsoil strata under earthquake loading is of concern. The numerical study presented in this research by means of a 3D dynamic fully coupled u-p analysis, addresses the effect of different parameters on shallow foundation settlement...
A robust short-circuit fault diagnosis for high voltage DC power supply based on multisensor data fusion
, Article 10th International Power Electronics, Drive Systems and Technologies Conference, PEDSTC 2019, 12 February 2019 through 14 February 2019 ; 2019 , Pages 659-664 ; 9781538692547 (ISBN) ; Kaboli, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Short-circuit fault (SCF) detection is mandatory in a high voltage DC power supply (HVPS) to prevent fatal damage. The majority of converters employ a single sensor to detect the SCF. This attribute increases the interference vulnerability of the fault detection (FD) system in the presence of noise. Therefore, miss detections and false alarms are possible to occur. Miss detections and false alarms are harmful catastrophes in most applications. A commonly used method to suppress the noise impacts is using a low-bandwidth low-pass filter. However, the use of the low-bandwidth low-pass filter reduces the speed of FD due to the filter delay. This paper proposes a fast FD algorithm based on...
A Fast vacuum arc detection method based on the neural network data fusion algorithm for the high-voltage dc power supply of vacuum tubes
, Article IEEE Transactions on Plasma Science ; 2020 ; Kaboli, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
Vacuum arc is one of the most important failure factors of the vacuum tubes. The amount of delivered energy from the high-voltage dc power supply to the vacuum tube is an important issue during the vacuum arc in the tube. Vacuum arc acts as a short-circuit fault (SCF) at the power supply output. The majority of converters use a single current sensor to measure only the converter output current for detecting the SCF. However, the sensor may provide unreliable data because of the noise effect. Application of a low-pass filter reduces the noise effect. Regarding the delay of the low-pass filter, the interval of arc detection increases and more energy is delivered to the tube. In this article, a...
A fast vacuum ARC detection method based on the neural network data fusion algorithm for the high-voltage DC power supply of vacuum tubes.رر
, Article IEEE Transactions on Plasma Science ; Volume 49, Issue 1 , 2021 , Pages 476-485 ; 00933813 (ISSN) ; Kaboli, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Vacuum arc is one of the most important failure factors of the vacuum tubes. The amount of delivered energy from the high-voltage dc power supply to the vacuum tube is an important issue during the vacuum arc in the tube. Vacuum arc acts as a short-circuit fault (SCF) at the power supply output. The majority of converters use a single current sensor to measure only the converter output current for detecting the SCF. However, the sensor may provide unreliable data because of the noise effect. Application of a low-pass filter reduces the noise effect. Regarding the delay of the low-pass filter, the interval of arc detection increases and more energy is delivered to the tube. In this article, a...
Parametric Study of Shallow Foundations Settlement Due to Liquefaction Phenomenon on a Two-Layered Soil
, M.Sc. Thesis Sharif University of Technology ; Pak, Ali (Supervisor)
Abstract
Settlement and tilt of structures due to liquefaction of subsoil layers is a major cause of damage during earthquake. Among different soil profile type, two layered soil is very common which was reported many times in differen earthquakes. Settlement of structures was measured by means of empirical methods before which were not viable because they do not consider different effective parameters. Consequently, different experimental studies performed to shed light on different aspects of liquefaction phenomena. In these studies, researchers consider some of the main parameters which have effect on the soil, otherwise, they neglected some important factors. So, numerical procedure is more...
Applying of Data Fusion Method for Improving the Protection System of the High Voltage DC Power Supply
, M.Sc. Thesis Sharif University of Technology ; Kaboli, Shahriyar (Supervisor)
Abstract
Short-circuit fault detection is mandatory in a high voltage DC power supply to prevent fatal damage. The majority of converters employ a single sensor to detect the short-circuit fault. This attribute increases the interference vulnerability of the fault detection system in the presence of noise. Therefore, miss detections and false alarms are possible to occur. Miss detections and false alarms are harmful catastrophes in most applications. A commonly used method to suppress the noise impacts is using a low-bandwidth low-pass filter. However, the use of the low-bandwidth low-pass filter reduces the speed of fault detection due to the filter delay. This paper proposes a fast fault detection...
Modeling Tsunami Wavesand Designinga Warning Systemfor This Phenomenon by UseofIT (Case Study the Sea of Oman)
, M.Sc. Thesis Sharif University of Technology ; Abbaspour Tehrani, Majid (Supervisor)
Abstract
Tsunami, like many other natural disasters leaves people a short time for escape. When talking about Tsunami, the escape time is the period it takes for the wave to start moving from the epicenter, change into a giant wave gradually and reach to a cost. In order to minimize damages of this phenomenon, the escaped time has to be estimated without delay. For this purpose the first needed action is modeling the Tsunami waves. Analytical and numerical models and software that are designed based on them do exist. To have an efficient and rapid Tsunami alarming system all of these options are examined in this project. Then having a reliable model quite a few probable scenarios are propounded. The...
Integration of Production Scheduling and Process Control Using Intelligent Controller
, M.Sc. Thesis Sharif University of Technology ; Vafa, Ehsan (Supervisor)
Abstract
In the present work, the integration of production scheduling and process control in a multi-product CSTR reactor is addressed. In order to reduce the complexity of solving this integrated problem, in the scheduling layer, a reduced closed-loop model, named scale bridging model, based on neural network concept is used. In the control layer, a neural network-based controller is used to achieve control objectives such as tracking, stability and robustness against model uncertainty. In addition, the designed closed loop system is used to obtain offline setpoint-output data set in order to train neural network based scale bridging model. In a comparative study, both simultaneous and sequential...
Hybrid Lead sulfide-graphene Quantum Dots: Optoelectronic Properties and Cytotoxicity Evaluation
, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdolreza (Supervisor)
Abstract
In recent years, quantum dots specially NIR QDs like lead sulfide have attracted a lot of attentions in various bioapplications such as bioimaging, stem cell tracking, etc. However, these materials are generally synthesized by using organic lagands like oleic acid which is not appropriate for bioapplications. Moreover, the cytotoxicity of these materials have severely restricted their applications. In this research, lead sulfide quantum dots were synthesized via a hot injection route. The nanocrystals had an average size of 3 nm passivated with oleic acid ligands and graphene nanosheets. Excitonic and photoluminescence peaks were observed in wavelengths of 950 and 1100 nm, respectively....
A performance-based approach for design of ground densification to mitigate liquefaction
, Article Soil Dynamics and Earthquake Engineering ; Volume 90 , 2016 , Pages 381-394 ; 02677261 (ISSN) ; Pak, A ; Ayoubi, P ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
In performance-based geotechnical earthquake engineering, the required degree and spatial extent of ground densification for mitigation of liquefaction beneath a structure should be determined based on the acceptable levels of performance of foundation. Currently, there is no solution for evaluation of the amount of settlement and tilt of footings constructed on a densified ground which is surrounded by a liquefiable soil. This implies the need for numerical procedures for simulation of seismic behavior of shallow foundations supported on both liquefiable and densified subsoil. In this paper, the dynamic response of shallow foundations on a densified ground is studied using a 3D fully...
A Vacuum arc diagnosis method for the high voltage power supply of vacuum tubes
, Article 2019 International Vacuum Electronics Conference, IVEC 2019, 28 April 2019 through 1 May 2019 ; 2019 ; 9781538675342 (ISBN) ; Rahmanian, M ; Kaboli, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Vacuum tubes are widely used for various applications. These vacuum tubes are supplied by high voltage power supplies. The amount of delivered energy from the high voltage power supply to the vacuum tube is an important issue during the vacuum arc in the tube. The protection mechanism consists of a shunt crowbar which diverts the fault current from the tube to itself as a parallel path. Detection of the vacuum arc is crucial and only one sensor is usually employed to detect the vacuum arc. This characteristic intensifies the interference susceptibility of the vacuum arc diagnosis system in a noisy environment. As a result of the noise, the arc detection system can report false alarms. False...
Dynamics and Structure of Active Poly[2]catenated Rings
, M.Sc. Thesis Sharif University of Technology ; Ejtehadi, Mohammad Reza (Supervisor)
Abstract
This thesis investigates the dynamics and structure of active poly[2]catenated rings, where activity is introduced by applying tangential active forces to monomers. The primary focus is to analyze the effect of activity on the system's structure and dynamics. Using molecular dynamics simulations, various physical quantities related to shape, size, structure, and dynamics of the chains are extracted and analyzed. Two configurations are examined. First, the symmetric system, in which both rings are equally active, aims to analyze the effects of activity percentage and ring length on the structure and dynamics of the two-ring system, and to compare the behavior of its rings with that of single...
Modeling and Analysis of Cylindrical Swellable Elastomers
, M.Sc. Thesis Sharif University of Technology ; Arghavani Hadi, Jamal (Supervisor)
Abstract
When swellable elastomer are surrounded by suitable fluid, they absorb the fluid and swell. This capability is used to design different tools. For example, drug release devises, sensors and actuators, in microfluidic devises such as micro-valves and micro-mixers, and seal devises. Most of these devises are shaped cylindrically. Therefore, have a thorough knowledge about how cylindrical swellable elastomer behavior, give us a good vision about how to design such actuators. In this thesis we have used constitutive equation of such materials and have investigated behavior of cylindrical swellable elastomers analytically and numerically. Analytical investigation is focused of transient behavior...
Supplier selection and order allocation in CLSC configuration with various supply strategies under disruption risk
, Article OPSEARCH ; Volume 57, Issue 3 , 2020 , Pages 908-934 ; Ghalehkhondabi, I ; Rafiee, M ; Namdar Zanganeh, S ; Sharif University of Technology
Springer
2020
Abstract
Supplier selection and order allocation are important keys for reverse logistics and closed-loop supply chain networks especially with the presence of demand–supply imbalance risks. If such uncertainties and risks are not foreseen in the chain, and corresponding appropriate measures are not taken to handle them, irreparable damages would be expected consequently. The importance of this issue in closed-loop supply chains is more appreciated due to the importance and the effect of this chain on the environment. In this research, the disruption risk and the uncertainties related to the demand, market price, and the number of returned products are simultaneously considered. Purchasing from the...
Numerical-probabilistic modeling of the liquefaction-induced free fields settlement
, Article Soil Dynamics and Earthquake Engineering ; Volume 149 , 2021 ; 02677261 (ISSN) ; Pak, A ; Pakzad, A ; Ayoubi, P ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Liquefaction is a phenomenon through which saturated sandy soil loses its shear strength and turns into a liquefied state. One of the most detrimental consequences of liquefaction is the reconsolidation volumetric settlements after the earthquakes, which is due to the dissipation of excess pore pressure caused by earthquakes. Severe floods can follow these settlements in free fields such as grounds close to the sea or rivers. Several researchers studied this phenomenon using data obtained from experiments in the lab or observations in the fields. Previous works were mainly based on a limited number of experimental observations and considered loadings and boundary conditions that were...
Underwater Hydrodynamics of Dolphin Craft
, M.Sc. Thesis Sharif University of Technology ; Sayadi, Hassan (Supervisor) ; Malaek, Mohammad Bagher (Supervisor)
Abstract
This dissertation accounts hydrodynamic coefficients for the hull form of Dolphine Craft using an Experimental-Numerical method. First, a short preface is mentionded about Dolphine craft and its charcterstics. Then, different methods for determining the hydrodynamic coeeficient are reviewed and the method used in this dissertation is introduced. After that, the selected methods will numerically be modeled. For accurate modeling, virtual labarotory is organizing for performing these tests During modeling, six degree freedom equation including the kinematic and Dynamics of body element are extractred and consequently, they are expressed for the rigid body and control volume of fluid. The...