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orouji--afsaneh
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The Impact of Negative/Positive Emotions on English Language Teachers` Identity: A Mixed-Method Research
, M.Sc. Thesis Sharif University of Technology ; Rezaei, Saeed (Supervisor)
Abstract
This study was a mixed-method research into the impact of emotions on the professional identities of teachers. The researcher followed Zembylas (2005a, 2005b) in conducting this study following the argument that politics and disciplinary power affect every aspect of teachers` life, hence their emotions and professional identities. Foucault (1975, 1984) was the source of theoretical underpinning in this study. The researcher used an open written interview, an attitudinal questionnaire, and a written narrative inquiry to collect the required data. Ten English language teachers (8 English Institute teachers, 2 public school teachers) took part in the first phase. One-hundred teachers from both...
Design and Optimization of Digital Microfluidic Chip for Cell Sorting
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor)
Abstract
Today, microfluidics, representing the precise and controlled displacement of small amounts of fluid, is one of the most efficient tools available in various research fields, including medicine. Digital microfluidics is one of the newest microfluidic methods, which is based on the theory of electrowetting on dielectric. According to this theory, by applying a voltage difference to a droplet of fluid on a hydrophobic surface, the droplet can be moved on that surface. Therefore, by fabricating a plate containing a number of electrodes completely isolated from each other and controlling them, small droplets of fluid can be moved on a hydrophobic surface. In this thesis, the electrodes of this...
Additive Manufacturing of Structured Stainless Steel Electrodes Functionalized with Transition Metal-Oorganic Frameworks for Water Splitting
, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdolreza (Supervisor)
Abstract
Water splitting reaction always faces challenges such as low efficiency, slow kinetics, and long-term instability of the catalyst. In this study, an electrode made of low-carbon 316 stainless steel fabricated by selective laser melting was initially used as the catalyst. The overpotential for hydrogen evolution reaction at a current density of 10 mA cm-2 using this electrode was calculated to be -0.505 V vs. RHE. This electrode had the capability of producing hydrogen gas at a rate of 3.6 mL min-1. Then, to reduce the overpotential, improve the efficiency, and stability of this electrode, its surface was modified by electrochemical methods, and metal-organic framework with cores of iron,...
Two-dimensional quantum simulation of scaling effects in ultrathin body MOSFET structure: NEGF approach
, Article 14th International Workshop on the Physics of Semiconductor Devices, IWPSD, Mumbai, 16 December 2007 through 20 December 2007 ; 2007 , Pages 240-242 ; 9781424417285 (ISBN) ; Dehdashti, N ; Faez, R ; Sharif University of Technology
2007
Abstract
For the first time, we present self-consistent solution of ultrathin body device structures to investigate the device parameters variation on the characteristics of nanoscale MOSFET. Our two dimensional (2-D) device simulator Is based on Nonequlibrium Green's Function (NEGF) forma lism. Starting from a basic structure (DG-MOSFET) with a gate length of 10 nm, variation of gate length, channel thickness, gate oxide parameters was carried out in connection with the numerical calculation of device characteristics. In this work Quantum transport equations are solved in 2-D by NEGF method in active area of the device to obtain the charge density and Poisson's equation is solved in entire domain of...
Design of Colorimetric Sensor Array for Simultanous Detection of Phosalone and Azinphosmethyl Pesticides Based on Aggregation Silver Nanoparticles (AgNPs)
, M.Sc. Thesis Sharif University of Technology ; Hormozinezhad, Mohammad Reza (Supervisor)
Abstract
Development of simple and rapid approaches for identification of pesticides has been known as a critical demand, due to the broad usage of pesticides and their harmful effects on mammals. Herein, we have introduced a silver nanoparticle (AgNP) based colorimetric sensor array for simultaneous identification of Azinphosmethyl (AM) and Phosalone (PS). In the presence of the target pesticides, unmodified AgNPs at various pHs (4.5, 5.5 and 9.5) showed different aggregation behaviours. As a result of aggregation, the color and UV-Vis spectra of AgNPs changed which led to distinct patterns for AM and PS. The aggregation induced spectral changes of AgNPs were used to identify AM and PS with the help...
Machine Learning-Assisted Colorimetric Assay Based on Au@Ag Nanorods for Chromium Speciation
, Article Analytical Chemistry ; Volume 95, Issue 26 , 2023 , Pages 10110-10118 ; 00032700 (ISSN) ; Ghasemi, F ; Hormozinezhad, M. R ; Sharif University of Technology
American Chemical Society
2023
Abstract
The oxidation state of an element significantly controls its toxicological impacts on biological ecosystems. Therefore, design of robust sensing strategies for multiplex detection of species with respect to their oxidation states or bonding conditions, i.e., chemical speciation, is quite consequential. Chromium (Cr) species are known as the most abundant inorganic groundwater pollutants and can be quite harmful to human health depending on their oxidation states. In the present study, a multicolorimetric probe based on silver-deposition-induced color variations of gold nanorods (AuNRs) was designed for identification and quantification of Cr species including Cr (III) and Cr (VI) (i.e.,...
Corrigendum to “ththnated development of a pH assisted AgNP-based colorimetric sensor array for simultaneous identification of phosalone and azinphosmethyl pesticides” [spectrochim. acta a mol. biomol. spectrosc. 219 (2019) 496–503](S138614251930455X)(10.1016/j.saa.2019.04.074)
, Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 223 , 2019 ; 13861425 (ISSN) ; Abbasi Moayed, S ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier B.V
2019
Abstract
The authors regret “There are some meaningless letters at the beginning of the article's title. The authors would like to inform that the correct title is “Development of a pH assisted AgNP-based colorimetric sensor Array for simultaneous identification of phosalone and azinphosmethyl pesticides.” The authors would like to apologise for any inconvenience caused. © 2019 Elsevier B.V
ThThnated Development of a pH assisted AgNP-based colorimetric sensor Array for simultaneous identification of phosalone and azinphosmethyl pesticides
, Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 219 , 2019 , Pages 496-503 ; 13861425 (ISSN) ; Abbasi Moayed, S ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Development of simple and rapid methods for identification of pesticides, due to their broad usage and harmful effects on mammals, has been known as a critical demand. Herein, we have introduced a silver nanoparticle (AgNP)based colorimetric sensor array for simultaneous identification of Azinphosmethyl (AM)and Phosalone (PS)pesticides. In the presence of the target pesticides, unmodified AgNPs at various pHs (4.5, 5.5 and 9.5)showed different aggregation behaviors. As a result of aggregation, the color and UV–Vis spectra of AgNPs changed differentially, leading to distinct response patterns for AM and PS. The aggregation induced spectral changes of AgNPs, were used to identify AM and PS...
Investigation of the Seismic Behavior of the Soil-Pile System with Three-Dimensional Nonlinear Modeling
, M.Sc. Thesis Sharif University of Technology ; Ahmadi, Mohammad Mehdi (Supervisor)
Abstract
A large number of structures and substructures, such as piles, have damaged or even yielded the entire structure during seismic loading. The kinematic interaction of piles under seismic loading has been widely studied from analytical, experimental, and numerical perspectives. In numerical modeling, most existing literature relies on simplified approaches to describe the soil-pile interaction, which leads to the need for more reliable and comprehensive research. In this research, the seismic response of the soil-pile system was investigated through a fully nonlinear three-dimensional numerical analysis in the time domain using the FLAC3D program. This model simulates the dependence of soil...
Providing Multicolor Plasmonic Patterns with Au@Ag Core-Shell Nanostructures for Visual Discrimination of Biogenic Amines
, Article ACS Applied Materials and Interfaces ; Volume 13, Issue 17 , 2021 , Pages 20865-20874 ; 19448244 (ISSN) ; Ghasemi, F ; Bigdeli, A ; Hormozi Nezhad, M. R ; Sharif University of Technology
American Chemical Society
2021
Abstract
Biogenic amines (BAs) are known as substantial indicators of the quality and safety of food. Developing rapid and visual detection methods capable of simultaneously monitoring BAs is highly desired due to their harmful effects on human health. In the present study, we have designed a multicolor sensor array consisting of two types of gold nanostructures (i.e., gold nanorods (AuNRs) and gold nanospheres (AuNSs)) for the discrimination and determination of critical BAs (i.e., spermine (SM), tryptamine (TT), ethylenediamine (EA), tyramine (TR), spermidine (SD), and histamine (HT)). The design principle of the probe was based on the metallization of silver ions on the surface of AuNRs and AuNSs...
A two-layer attack-robust protocol for IoT healthcare security: Two-stage identification-authentication protocol for IoT
, Article IET Communications ; Volume 15, Issue 19 , 2021 , Pages 2390-2406 ; 17518628 (ISSN) ; Sepideh, A ; Ali, M ; Salah, A. M ; Sharif University of Technology
John Wiley and Sons Inc
2021
Abstract
The majority of studies in the field of developing identification and authentication protocols for Internet of Things (IoT) used cryptographic algorithms. Using brain signals is also a relatively new approach in this field. EEG signal-based authentication algorithms typically use feature extraction algorithms that require high processing time. On the other hand, the dynamic nature of the EEG signal makes its use for identification/authentication difficult without relying on feature extraction. This paper presents an EEG-and fingerprint-based two-stage identification-authentication protocol for remote healthcare, which is fast, robust, and multilayer-based. A modified Euclidean distance...
A two-layer attack-robust protocol for IoT healthcare security: Two-stage identification-authentication protocol for IoT
, Article IET Communications ; Volume 15, Issue 19 , 2021 , Pages 2390-2406 ; 17518628 (ISSN) ; Sepideh, A ; Ali, M ; Al-Majeed, S ; Sharif University of Technology
John Wiley and Sons Inc
2021
Abstract
The majority of studies in the field of developing identification and authentication protocols for Internet of Things (IoT) used cryptographic algorithms. Using brain signals is also a relatively new approach in this field. EEG signal-based authentication algorithms typically use feature extraction algorithms that require high processing time. On the other hand, the dynamic nature of the EEG signal makes its use for identification/authentication difficult without relying on feature extraction. This paper presents an EEG-and fingerprint-based two-stage identification-authentication protocol for remote healthcare, which is fast, robust, and multilayer-based. A modified Euclidean distance...
A wide-range pH indicator based on colorimetric patterns of gold@silver nanorods
, Article Sensors and Actuators B: Chemical ; Volume 358 , 2022 ; 09254005 (ISSN) ; Abbasi Moayed, S ; Ghasemi, F ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier B.V
2022
Abstract
The potential of hydrogen (pH) is a basic and critical parameter representing the function of numerous chemicals/biomolecules. Due to the widespread applications of pH in diverse fields, the development of rapid and simple yet reliable probes for the determination of pH has attracted significant interest. In this paper, by using AuNRs, silver ions, and ascorbic acid as colorimetric pH sensor, a multicolorimetric nanosensor is described for pH measurement. The reduction of silver ions by ascorbic acid which is strongly influenced by pH, results in silver nanoshell deposition on the surface of AuNRs. Consequently, the formation of Au@Ag core-shell NRs causes a series of blue shifts in the...
Design of Colorimetric Sensor Arrays Based on Gold Nanorods for Speciation and Discrimination of Biomolecules and Environmental Pollutants
, Ph.D. Dissertation Sharif University of Technology ; Hormozinezhad, Mohammad Reza (Supervisor) ; Ghasemi, Forough (Co-Supervisor)
Abstract
The vivid optical properties of gold nanorods (AuNRs) arising from their unique structural anisotropy have been an object of fascination in a broad range of applications over the past decade. The pseudo-one-dimensional rod-shaped morphology of AuNRs underlies two distinct LSPR bands attributed to the longitudinal and the transversal oscillation of the surface plasmons. Indeed, the brilliant and high-contrast rainbow color tonality of AuNRs primarily emanates from the dramatic dependency of the location of the aforementioned bands on the aspect ratio of the nanorods. It is so profound that a minute increment of the aspect ratio is followed by a significant redshift of the longitudinal peak...
Photocatalytic Conversion of Carbon Dioxide to Value-Added Products Using Pt Containing Catalysts
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
Abstract
The conversion of CO2 gas into value-add chemicals known as solar fuel technology attracted much consideration from the beginning of the 21st century owing to the potential of this technology in solving the climate change and energy shortage issues. In the present study, a well-known photocatalyst, TiO2, was doped with Bismuth element and was subjected to Pt nanoparticles loading as a cocatalyst to boost the photocatalytic CO2 conversion. Pristine TiO2 and Bi-doped samples were prepared by sol gel method. Then, a facile photo-deposition method was employed to introduce Pt onto the surface of TiO2. Various characterization techniques including XRD, DRS, BET, PL, FTIR, FESEM and TEM, were used...
Production of Biodiesel Using Eggshell as Catalyst
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
Abstract
The aim of this project is to investigate and synthesize CaO-based nanocatalysts derived from chicken eggshell calcination with alkali metals and sodium-potassium compounds promoters used in the transesterification reaction of canola oil and methanol. Sections of this thesis include the synthesis of nanocatalysts, catalyst characterization tests, and investigation of reaction under optimal conditions. Two groups of catalysts containing different weight percentages of alkali metals based on CaO and 1 %wt sodium-potassium based on CaO with different weight percentages of these two elements were synthesized by wet impregnation method and used in the reaction under optimum condition. Catalyst...
Oxidation Desulfurization of Liquid Fuels Using TiO2-based Photocatalysts
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
Abstract
Due to the increasing consumption of fuel, the use of new methods with high efficiency to remove sulfur from fossil fuels is felt more than ever. Hydrogenation and oxidation of sulfur organic matter, such as thiophenes, is an old method of desulfurization of liquid fuels. Using a photocatalyst, everything can be done in an environment that is very low cost. In this study, the photocatalytic elimination of dibenzothiophene was investigated. For this purpose, carbon-doped thiamine dioxide was used as the photocatalytic base, which is synthesized by hydrothermal method. This method is the same source of titanium and carbon. To increase the performance of the catalyst, platinum metal was loaded...
Effect of Selected Promotors on the Electrocatalytic Performance in Oxygen Evolution Reaction
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Cyrus (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
Abstract
During the last few decades, efforts have been made to replace fossil fuels with clean and non-absorbent energy sources. One of the promising strategies is energy production by hydrogen storage using water splitting. For this purpose, different methods of using light, heat and electricity are provided. Electrolysis of water with a simple environment such as very high purity of hydrogen produced, controllable, device, no need for high temperature and pressure in the reactor and huge potential for industrial applications has been very much considered. Water electrolysis consists of two reactions: reduction of water to hydrogen (HER) and oxidation of water to oxygen (OER). The second reaction...
Synthesis and Evaluation of Nanostructured Magnetic Photocatalysts for Oxidation Desulfurization of Liquid Fuels
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Sirous (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
Abstract
In recent decades, desulfurization processes have become necessary to reduce environmental pollution due to fuel sulfur emissions. In this research, in order to photocatalytic oxidation desulfurization of liquid fuel, a model fuel (normal octane) under visible light irradiation of 250 W sodium lamp, using H2O2 oxidant and methanol solvent in the presence of BMO/Fe@MIL(x%) composite. BMO and Fe@MIL were investigated. From the tests, X-ray diffraction, scanning and transmission electron microscope imaging, absorption and desorption of nitrogen gas, infrared spectrometer-Fourier transform, visible-ultraviolet reflection spectroscopy, optical radiation spectroscopy and vibration magnetometer in...
Design of Optimum Nanoantenna Arrays for Detection Applications
, Ph.D. Dissertation Sharif University of Technology ; Rashidian, Bijan (Supervisor) ; Shahmansouri, Afsaneh (Co-Supervisor)
Abstract
The main goal of this thesis is introducing a method to design optimum nanoantenna arrays for detection applications. The proposed method is based on the multiple-scattering T-matrix in connection with the Ewald method. The formulation is systematic, quite general, easily traceable, and fast. Its high speed of analysis makes it well suited to design optimizations.In particular, we calculate multiple-scattering terms of the T-matrix formulation with the Ewald method. To the best of our knowledge no report on derivation of the T-matrix of a 3D (or even 2D) periodic array from the T-matrix of the isolated element, based on Ewald method has been reported before.Finally, a software has been...