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    Simultaneous Analysis of Aliphatic Alcohols Mixtures Using an Electronic Nose Based on Nano/Microstructured Conducting Polypyrrole Film Prepared by Catalytic Electropolymerization on Cu/Au Interdigital Electrodes Using Multivariate Calibration

    , Article IEEE Sensors Journal ; Volume 16, Issue 2 , 2016 , Pages 418-425 ; 1530437X (ISSN) Alizadeh, N ; Babaei, M ; Alizadeh, M. S ; Mani Varnosfaderani, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    In this paper, nano/microstructured-conducting polypyrrole has been prepared on Cu/Au interdigital electrode surfaces by using constant potential amperometry technique. The Fe(II) ions were used as catalyst and X = ClO4 -, pTs-, Cl-, TCA-, DS-, DBS- was implemented as anion dopants. The morphologies of the films were investigated by field emission scanning electron microscope. A remarkable dependence was observed between the type of anion dopant and the morphology of polypyrrole (PPy). The sensing behavior of the PPy-X sensor has been studied toward acetone, methanol, ethanol, 1-propanol, 2-propanol, nitromethane, propylamine, pyridine, and gas mixtures of aliphatic alcohols. The responses... 

    Comparing half-metallic, MOKE, and thermoelectric behavior of the CrTiZ (Z = As, P) half-Heuslers: A DFT study

    , Article Materials Research Express ; Volume 8, Issue 4 , 2021 ; 20531591 (ISSN) Sadeghi, M ; Zelati, A ; Boochani, A ; Arman, A ; Mirzaei, S ; Sharif University of Technology
    IOP Publishing Ltd  2021
    Abstract
    Structural, half-metallic, magneto-optic, and thermoelectric properties of CrTiZ (Z = As, P) half-Heusleres compounds are investigated based on density functional theory. These compounds have mechanical stability in the ferromagnetic state with a high bulk modulus. They are often half-metallic with a large and integer magnetic moment and are very attractive in spintronics, magneto-optics applications. The magnetic moments of CrTiAs and CrTiP were 2.9865 μB and 3.00 μB, respectively, which were attributed to their ferromagnetic phase. Additionally, the positive sign of the phonon branches indicates the dynamic stability of these compounds. Applying both GGA and mBJ approximations, CrTiAs and... 

    The Effect of Rudder Angle on Ship’s Fuel Consumption

    , M.Sc. Thesis Sharif University of Technology Sadeghi Bughar, Babak (Author) ; Khorasanchi, Mahdi (Supervisor) ; Zare, Arman (Co-Supervisor)
    Abstract
    The aim of this research is to investigate the effect of speed and direction of current on ship fuel consumption. A KCS benchmark model has been numerically studied in calm water and fourteen current and wind conditions with the same speed and different directions to determine how the ship performance is dependent on flow conditions. The model has been simulated in an artificial basin propelled by a single right-handed propeller via a CFD commercial code. Numerical results revealed a linear relationship between the deviation of current and wind from head-sea or following-sea conditions and the rudder angle. The head-sea and following-sea currents and winds increased and decreased the lateral... 

    High performance grout connection for pre-cast concrete structures

    , Article International Conference on Sustainable Construction Materials and Technologies, Coventry, 11 June 2007 through 13 June 2007 ; 2007 , Pages 479-485 ; 9780415446891 (ISBN) Alizadeh Kharazi, M ; Sharif University of Technology
    2007
    Abstract
    Connections have very important role in pre-cast concrete structures, especially in seismic zones, and grout connections increase strength and resistance of pre-cast concrete structures for lateral forces. High performance grout connections (HPGC) provide new opportunities to design cost-effective pre-cast concrete structures. HPGC have been proposed to decrease cost of insulation, erection and crane cost of pre-cast concrete structures and to overcome weakness of traditional pre-cast concrete structure connections .This research focuses on properties of grout materials properties which produced in Iran and the effect of propylene fiber on the performance of grout connection. In the first... 

    Evaluation of the topographical surface changes of silicon wafers after annealing and plasma cleaning

    , Article Silicon ; Volume 12, Issue 11 , 2020 , Pages 2563-2570 Stach, S ; Ţălu, Ş ; Dallaev, R ; Arman, A ; Sobola, D ; Salerno, M ; Sharif University of Technology
    Springer Science+Business Media B.V  2020
    Abstract
    Purpose: The morphological stability of silicon single crystal wafers was investigated, after performing cleaning surface treatments based on moderate temperature annealing and plasma sputtering. Methods: The wafer surfaces were measured by Tapping mode atomic force microscopy in air, before and after the different treatments. The 3D images were segmented by watershed algorithm identifying the local peaks, and the stereometric parameters were extracted thereof. The analysis of variance allowed to better assess the statistically significant differences. Results: All the resulting quantities were critically discussed. It appeared that the different cleaning treatments affected differently the... 

    Stock Price Forecasting Using Neural Networks and Fuzzy Logic

    , M.Sc. Thesis Sharif University of Technology Alizadeh, Parisa (Author) ; Shavandi, Hassan (Supervisor)
    Abstract
    This research proposes a novel hybrid method for stock price index forecasting relying on technical analysis, the fundamental analysis of capital market, neural networks technology, and fuzzy logic. The new method shows a good performance comparing complicated and time-consuming forecasting methods. Several factors influence stock price; for example, an important one is the previous trend of stock price. Fortunately, by developing technical analysis and introducing the various indices of this method the maximum use of historical data is made in order to forecast future prices. Another kind of factors is macro-economic variables that their influence on the long-term trends of the stock... 

    Access Control in Semantic Social Network

    , M.Sc. Thesis Sharif University of Technology Alizadeh, Mahdi (Author) ; Jalili, Rasoul (Supervisor)
    Abstract
    Growth of tools that ease sharing information and resources in social networks can cause privacy issues for the users. Protecting user’s personal information against unauthorized access is a crucial task, and it is considered as a first step for preserving user’s privacy in such networks. Policies, access control rules, and the way rules are applied to online social networks are issues that are less investigated and most existing frameworks have used simple models. Growth of users joining social networks and significant volume of resources shared in these networks make such environments suitable for using semantic technology. Semantic technology is used for modeling various resources, users,... 

    Synthesis of Magnetic Fe3o4 Nanoparticle and Coating It with Modified Starch for Targeted Delivery of Doxorubicin Anticancer Drug

    , M.Sc. Thesis Sharif University of Technology Alizadeh, Mahshid (Author) ; Pourjavadi, Ali (Supervisor)
    Abstract
    One of the major problems in cancer treatment is side effects of treatments. Today, scientists have developed smart nanocarrier for diagnosis and drug delivery that can circulate in the bloodstream, pass the body's immune system to kill cancer cells and attach to the cancer cells to deliver drugs, without the side effects that are in other treatments, such as chemotherapy. magnetic nanoparticles coated by biodegradable polymers are one of the smart polymers. In this study, iron oxide nanoparticles with amine group on their surface are coated by starch modified by methyl acrylate then reacted with hydrazine and hydrazide functional group is formed that can chemically be bonded with the... 

    Algorithms of Scientometrics Including PageRank and its Generalization to the Interval Matrices

    , M.Sc. Thesis Sharif University of Technology Alizadeh, Zahra (Author) ; Mahmoodian, Ebadollah (Supervisor)
    Abstract
    Due to the increasing number of research activities across the world,the academic societies are in the urgent need of appropriate criteria and methods for the evaluation of scientific publications. The term ‘Scientometrics’ has been coined to describe the methodology of aforementioned scientific assessment. Introduction of comprehensive and universal scientific rankings could provide inexperienced researchers with the opportunity to select most qualified publications for their literature reviews on the basis of such rankings. This procedure seems to be more convenient and reliable.In this framework, a review of most commonly used scientometric principles and methods are presented in the... 

    Design and Analysis of a Force-Isotropic Underactuated Humanoid Hand

    , M.Sc. Thesis Sharif University of Technology Alizadeh, Milad (Author) ; Zohoor, Hassan (Supervisor)
    Abstract
    Robots have been widely used for various applications, especially during the last decades. Robots are made of several parts, in which, "Hand" is one of the most important of those. Hands are designed according to their applications and are not necessarily like human ones. Development of humanoid robots, however, brings a special place to human-like hands. In this research, a force-isotropic underactuated finger with two phalanxes and one actuator is designed, considering design limitations and through static analysis. Tendon, cam and mechanical lock (ratchet gear) are among the main components which have been considered in the finger design. Then, a model was fabricated and tested in order... 

    Analysis of Losses in Articial Dilectric Waveguides at Mm-Wave Frequencies

    , M.Sc. Thesis Sharif University of Technology Alizadeh, Arman (Author) ; Rejaei, Behzad (Supervisor)
    Abstract
    Today as various electronic and telecommunication devices like cell phones and PDAs are being popularized, MMIC technology is gaining a significant importance. One of the priorities of this technology is trying to miniaturize these popular devices. But reducing size of passive microwave components used in these devices requires microwave wavelength to decrease.Components fabricated by conventional deposition techniques aren’t thick enough to reduce the wavelength, so permittivities much higher than those of conventional dielectrics could be a possible solution. Artificial dielectric layers (ADL) can provide such high permittivities.So utilizing these layers can possibly reduce the size of... 

    A Model for Public Project Evaluation and Selection Based on Citizen Satisfaction

    , Ph.D. Dissertation Sharif University of Technology Alizadeh, Alireza (Author) ; Kianfar, Fereydoon (Supervisor)
    Abstract
    Public projects are those projects that are run by public financial resources such as tax or other national governmental incomes. Selection of these projects is relatively difficult due to their importance, long life-time, and high costs. In most models developed in previous studies to select public projects, financial matters and risks are the only factors which were considered. However, the public projects should naturally be selected in a way that citizens’ benefits are maximized (in both short- and long-term) and citizens’ living level increases. In other words, public projects should be selected to increase citizens’ satisfaction. In this thesis, a model for public projects is presented... 

    Investigation of the Performance and Mechanism of Permeation through Biological Membranes

    , Ph.D. Dissertation Sharif University of Technology Alizadeh, Ali (Author) ; Parsafar, Gholamabbas (Supervisor)
    Abstract
    Ion channels are present in all cell membranes which are the important part of the performances in regulating the flow across the membrane as well as the signaling. We have investigated the water permeation through carbon nanotube (CNT) membranes as a model for the synthetic ion channels, i.e. peptide nanotube channels (PNCs). The effect of different charge configured CNTs which tailored based on these ion channels on the water permeation has been studied. In addition, the temperature dependence of the permeation using statistical models such as continuous time random walk model (CTRW) via molecular dynamics simulation has been investigated. We have found that there is a jump in the... 

    Temperature dependence and the effect of charge configuration on water permeation through modified carbon nanotubes: A simulation study

    , Article Fluid Phase Equilibria ; Volume 363 , 15 February , 2014 , Pages 282-289 ; ISSN: 03783812 Alizadeh, A ; Parsafar, G ; Sharif University of Technology
    2014
    Abstract
    We have investigated the water permeation through carbon nanotube (CNT) membranes as a model of peptide nanotube channels (PNCs). The effect of different charge configured CNTs which tailored based on some artificial ion channels on the water permeation through the channels have been studied. In addition, the temperature dependence of the permeation has been investigated. We have found that there is a jump in the permeation which is somehow related to the characteristics of each channel and the temperature of this permeation jump changes according to the channel configuration. Our investigation on the channels shows that the temperature at which the permeation jump occurs is related to the... 

    Developing a model for citizens' satisfaction with public sector services based on rough sets theory: A case study of Tehran municipality

    , Article Tehnicki Vjesnik ; Volume 20, Issue 5 , 2013 , Pages 795-802 ; 13303651 (ISSN) Alizadeh, A ; Kianfar, F ; Sharif University of Technology
    2013
    Abstract
    Original scientific paper Developing a model for citizens' satisfaction with public services is one of the effective factors for improvement of service quality. In recent years, many studies have been carried out to identify a model for citizens' satisfaction with public sector services. In the structure of the presented models in the literature, one of the most important issues regarding organizations giving public services is identification of service scopes that have the most impact on citizens' satisfaction. This paper aims to develop a model to identify citizens' satisfaction status with public services. To do so, first, key factors influencing citizens' satisfaction with public... 

    On lob algebras, II

    , Article Logic Journal of the IGPL ; Volume 20, Issue 1 , April , 2012 , Pages 27-44 ; 13670751 (ISSN) Alizadeh, M ; Ardeshir, M ; Sharif University of Technology
    2012
    Abstract
    We study the variety of Löb algebras, the algebraic structures associated with Formal Propositional Calculus. Among other things, we show that there exist only two maximal intermediate logics in the lattice of intermediate logics over Basic Propositional Calculus. We introduce countably many locally finite sub-varieties of the variety of Löb algebras and show that their corresponding intermediate logics have the interpolation property. Finally, we characterize all chain basic algebras with empty set of generators, and show that there are continuum many such chain basic algebras  

    Choosing a Suitable Microalgae for Bioremediation of Heavy Metals Regarding Iran's Clamate

    , M.Sc. Thesis Sharif University of Technology Alizadeh, Mahsa (Author) ; Yaghmaei, Soheyla (Supervisor)
    Abstract
    The pollution of water resources with heavy metals as a result of industrial activities threatens the lives of all living organisms. Therefore, separation of heavy metals from wastewater before entering our invironment is very important. Various chemical and physical methods such as absorption, chemical precipitation, extraction by solvent and ion exchange can be used to separate heavy metals but each of these methods have their own problems such as imperfect separation of heavy metals, need for expensive facilities and refining systems, high energy consumption and leaving pollutant residuals that need to be separated. On the other hand, the methods mentioned above can not separate heavy... 

    On Temperature Dependency of Delay for Local,Intermediate, and Repeater Inserted Global Copper Interconnects

    , Article IEEE Transactions on Very Large Scale Integration (VLSI) Systems ; Volume 23, Issue 12 , 2015 , Pages 3143-3147 ; 10638210 (ISSN) Alizadeh, A ; Sarvari, R ; Sharif University of Technology
    2015
    Abstract
    Cryogenic technologies not only improve the performance of interconnects but also the performance of transistors and consequently drivers and repeaters. Although in cryogenically cooled integrated circuits the local temperature of interconnects and transistors may be as low as 50 K, it may easily reach to 600 K in high-temperature chips. In this brief, we investigated the impact of temperature on the delay of local, intermediate, unit-repeater-inserted (URI), and cascaded repeater-inserted (CRI) global copper interconnects for minimum technology node with available transistor model (32-nm technology). Our results show that temperature variation of driver resistance could change the delay of... 

    A broadband integrated class-J power amplifier in gaas pHEMT technology

    , Article IEEE Transactions on Microwave Theory and Techniques ; Volume 64, Issue 6 , 2016 , Pages 1822-1830 ; 00189480 (ISSN) Alizadeh, A ; Medi, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    This paper presents a design methodology for class-J monolithic microwave integrated circuit (MMIC) power amplifiers (PAs). Theoretical derivations of optimum load impedances, output power, efficiency, and maximum bandwidth are described in presence of nonlinear drain-source resistance of transistors (RDS). A procedure is developed for ideal transistor sizing where transistors are concurrently stabilized and sized to achieve the maximum power-added efficiency (PAE). A 3.5-7 GHz, 0.5-W class-J PA is implemented in a 0.1-μm AlGaAs-InGaAs pHEMT technology to check the accuracy of the proposed approach. With chip dimensions of 1.57 × 1.29 mm2, the PA achieves 56% average PAE over the frequency... 

    Analyzing Community Evolution on Open Source Development Networks

    , M.Sc. Thesis Sharif University of Technology Alizadeh, Hamid (Author) ; Khansari, Mohammad (Supervisor)
    Abstract
    Open source software development is growing rapidly according to request of market. Different types of analysis have done on open source development networks to extract knowledge and help both developers and users to decide better. In this thesis, we try to extract data from one of the biggest open source development repositories GitHub and then a community detection algorithm will apply on these data for different time stamps. Then we propose an evolution tracking model and implement it to detect evolution of communities from 2013 until 2015. Then communities size evolution and changes in communities such as growth, dissolve, merge, split and formation will be discussed. After that we...