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zeidabadi-nejad--leila
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Synthesis of Pt- Nanoparticle in Ionic Liquid Coated on Alumina and the Investigation of the Nature and Thickness of Ionic Liquid on Catalyst Pt / Al2O3
, M.Sc. Thesis Sharif University of Technology ; Gholami, Mohammad Reza (Supervisor)
Abstract
In this project ionic liquid and there mixtures were coated on Pt/ Al2O3 , the prepared catalyst were characterization by SEM, BET and XRD techniques.In the first stage the effect of the coated ionic liquid on the Pt/Al2O3 were investigated, on the rate of C=C hydrogenation. in the second stage effect of the thickness of ionic liquids on the rate of the cyclohexene hydrogenation were studied. Result revelad that by increasing the ionic liquid polarity, the reaction rate increased. Also the reaction rate decreased by increasing the thickness of ionic liquid
Synthesis and properties of biodegradable hydrogels of κ-carrageenan grafted acrylic acid-co-2-acrylamido-2-methylpropanesulfonic acid as candidates for drug delivery systems
, Article Reactive and Functional Polymers ; Volume 67, Issue 7 , 2007 , Pages 644-654 ; 13815148 (ISSN) ; Barzegar, Sh ; Zeidabadi, F ; Sharif University of Technology
2007
Abstract
Novel types of highly swelling hydrogels were prepared by grafting crosslinked polyacrylic acid-co-poly-2-acrylamido-2-methylpropanesulfonic acid (PAA-co-PAMPS) chains onto κ-carrageenan through a free radical polymerization method. Here, we propose a mechanism for κ-carrageenan-g-PAA-co-PAMPS formation and confirm the hydrogel structure using FTIR spectroscopy. The effect of grafting variables (i.e. concentration of methylenebisacrylamide (MBA), acrylic acid/-2-acrylamido-2-methylpropanesulfonic acid (AA/AMPS) weight ratio, ammonium persulfate (APS), κ-carrageenan, neutralization percent and reaction temperature) were systematically optimized to achieve a hydrogel with a maximum swelling...
Investigation of the Liquid Viscosity Effect on the Rising Bubble Motion (Effect of Ethylene Glycol Concentration on Terminal Velocity)
, M.Sc. Thesis Sharif University of Technology ; Bastani, Dariush (Supervisor) ; Lotfi, Marzieh (Co-Advisor)
Abstract
Surface phenomena is one of the fundamental branches of science that has many applications in industries related to multiphase processes. One of the most important issues of this knowledge is inter-phase transport phenomena in contacting gas - liquid and liquid – liquid systems. Multiphase systems generally include dispersions such that in many cases are associated with the relative motion between the continuous and dispersed phase. One of the most widely used inter-phase flow systems is dispersion of gas bubbles in the bulk of liquid. The overall efficiency of these systems is often determined by the characteristics of the gas phase. In order to understand the dynamic behavior of such...
Structural Health Monitoring based on Emprical Wavelet Transform and Fuzzy Logic
, M.Sc. Thesis Sharif University of Technology ; Bakhshi, Ali (Supervisor) ; Ghodrati Amiri, Gholamreza (Supervisor)
Abstract
Performance of civil infrastructures, such as high-rise buildings, bridges, tunnels, offshore platforms and other structures may be critically influenced by existence of structural damages or even lead to devastating consequences. Structural Health Monitoring(SHM) and damage detection denotes the ability to monitor the performance of structure, detect and assess any damage at the earliest stage in order to reduce the life-cycle cost of structure and improve its reliability and safety. Generally, damage is defined as some changes in the physical properties of a structure, such as stiffness matrix. On the other hand, presence of damage causes changes in structural dynamic characteristics, such...
Improving self-care and health literacy in hemodialysis patients: Using software engineering
, Article Proceedings - 2012 7th International Conference on Computing and Convergence Technology (ICCIT, ICEI and ICACT), ICCCT 2012, 3 December 2012 through 5 December 2012 ; December , 2012 , Pages 317-320 ; 9788994364216 (ISBN) ; Edalat-Nejad, M ; Edalat-Nejad, N ; Sharif University of Technology
2012
Abstract
The use of Computer Science in order to categorize and store information, improve diagnostic and therapeutic procedures, patient education and the training of a skilled labor force, has taken important steps and there are constantly new developments in this area
Complex Activity Recognition by Means of an IMU-Based Wearable System for the Purpose of PD Patients’ Rehabilitation
, M.Sc. Thesis Sharif University of Technology ; Behzadipour, Saeed (Supervisor) ; Ali Beiglou, Leila (Co-Supervisor)
Abstract
Parkinson's is a disease caused by a disorder in the central nervous system of the body. There is no definite cure for this disease, but one of the ways to prevent the progress of this disease is to use movement therapy. One of the goals of designing wearable systems consisting of inertial sensors is to make it possible to perform this movement therapy from a distance. The purpose of the present study and research is to use the approach of simple and complex activities in order to increase the accuracy in the detection of activities and also to solve the problems of the previous system, with the help of creating the ability to detect complex meaningful activities for Parkinson's patients. In...
Introduction of clinical, simulation-based software for medical sciences teachings
, Article Procedia Engineering ; Volume 29 , 2012 , Pages 43-47 ; 18777058 (ISSN) ; Edalat-Nejad, M ; Edalat Nejad, N ; Edalatnejad, M ; Sharif University of Technology
2012
Abstract
Simulation is the gold standard for training in aviation and trauma medicine. Now it is available for diseases diagnosis and treatment. With simulation, clinicians can practice their art in a realistic, consequence free environment, combining both theory and practice in a comprehensive program. Method and materials - In the virtual clinical environment of "VPsoft mentor" software, the practitioner reviews a patient's history, orders laboratory tests and procedures, interprets findings, renders diagnoses, and prescribes medication. Every diagnostic or treatment decision the clinician makes for the patient is analyzed by E-mentor, providing instant feedback.Results - This software have been...
Using three-dimensional finite element analysis for simulation of residual stresses in railway wheels
, Article Engineering Failure Analysis ; Vol. 45, issue , October , 2014 , p. 449-455 ; Sharif University of Technology
2014
Abstract
One of the most important issues in railway wheels is residual stresses. It is desirable to produce less residual stresses when possible and to decrease the remaining residual stresses in the wheels. The objective of this paper is to provide an estimation of the residual stresses in the rail wheel caused by the stress field from heat treatment process of a railway wheel. A three-dimensional nonlinear stress analysis model has been applied to estimate stress fields of the railway mono-block wheel in heat treatment process. After forging or casting, railway wheels are heat-treated to induce the desirable circumferential compressive residual stress in the upper rim. Finite element analysis...
The Use of Non-platinum Electro-catalyst for Low Temperature Fuel Cells
, M.Sc. Thesis Sharif University of Technology ; Samiee, Leila (Supervisor) ; Seifkordi, Ali Akbar (Co-Advisor)
Abstract
In the recent decades, Polymer Electrolyte Membrane Fuel Cells (PEFC) have been known as an appropriate type of fuel cells, due to being electrochemical converter and clean energy generator with high power density and having low operation temperature and launch time. Palatine is one of the major materials that are used in electro-catalysts of fuel cell. Due to shortage of palatine resources and its high price, fuel cell production is not economical. To achieve economic conditions for production of fuel cell, two major methods are proposed:
1) Reduction of the employed amount of palatine in electro-catalyst
2) Full replacement of palatine with cheap materials
In the current...
1) Reduction of the employed amount of palatine in electro-catalyst
2) Full replacement of palatine with cheap materials
In the current...
Equations of motion of a ring-like robot with a flexible body and creeping-rolling motion
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings ; 2010 , pp. 191-197 ; ISBN: 9780791843833 ; Alasty, A ; Sharif University of Technology
2010
Abstract
The robots that can move on rough terrains are very important especially in Rescue operation, exploration, etc. In this research, a mechanism is introduced for a ring-like robot with a flexible body. This robot is moved by arms which are placed radially and have Reciprocating motion in this direction. By controlling the contraction and the extension of the arms which contact lhe ground, the robot will be forced to move which is called rolling-creeping motion. The robot is stable in stationary state.; also the maximum angle which it can be stable is determined. Considering the speed of contracted arm is the input parameter, the speed of the extended arm for locomotion of the robot has been...
Optimization of platinum extraction by Trioctylphosphine oxide in the presence of alkaline-metal salts
, Article Procedia Engineering, 25 August 2012 through 29 August 2012 ; Volume 42 , August , 2012 , Pages 1302-1312 ; 18777058 (ISSN) ; Kazemeini, M ; Sharif University of Technology
2012
Abstract
Effect of alkaline metal salts on the solvent extraction of platinum from leached spent dehydrogenation catalysts (Pt/Al2O3) in aqua-regia by the Trioctylphosphine oxide (TOPO) has been investigated. Best salting out effect was achieved using KCl as the additive salt in which process upto 90% of Platinum extraction achieved. Response Surface methodology utilized in order to design the experiments, model the extraction process for platinum and aluminum as well as; optimize the whole process. It was shown that solvent extraction of platinum by TOPO was kinetically fast and the needed equilibrium time for it was less than 30 seconds. In the present study, proposed models for platinum and...
A novel overlap-based logic cell: An efficient implementation of flip-flops with embedded logic
, Article IEEE Transactions on Very Large Scale Integration (VLSI) Systems ; Volume 18, Issue 2 , 2010 , Pages 222-231 ; 10638210 (ISSN) ; Maymandi Nejad, M ; Sharif University of Technology
2010
Abstract
This paper presents several efficient architectures of dynamic/static edge-triggered flip-flops with a compact embedded logic. The proposed structure, which benefits from the overlap period, fixes most of the drawbacks of the dynamic logic family. The design issues of setting the appropriate overlap period for this architecture are explained. The proposed overlap-based approach is compared with several state-of-the-art dynamic/static logic styles in implementing a 4-bit shift register and an odd-even sort coprocessor using different CMOS technologies. The simulation results showed that the overlap-based logic cells become much more efficient when the complexity of their embedded logic...
Significant enhancement in the efficiency of photoconductive antennas using a hybrid graphene molybdenum disulphide structure
, Article Journal of Nanophotonics ; Volume 10, Issue 3 , 2016 ; 19342608 (ISSN) ; Safian, R ; Sharif University of Technology
SPIE
2016
Abstract
We propose a hybrid graphene molybdenum disulphide-based photoconductive antenna to overcome the restrictions of metallic photoconductive antennas and graphene-based photoconductive antennas, simultaneously. The structure is composed of a hybrid graphene-MoS2 strip as the antenna deposited on a low-temperature gallium arsenide substrate. A full-wave electromagnetic solver, namely, high frequency structural simulator (HFSS) is used to analyze the whole structure. It is shown that the proposed photoconductive antenna provides us with not only high input impedance and reconfigurability but also high values of matching efficiency and radiation efficiency. The impact of increasing MoS2 layers on...
A graphene-based THz ring resonator for label-free sensing
, Article IEEE Sensors Journal ; Volume 16, Issue 11 , 2016 , Pages 4338-4344 ; 1530437X (ISSN) ; Safian, R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
In this paper, we report on a novel resonant THz sensor for label-free analysis. The structure consists of a silicon nitride dielectric ring resonator vertically coupled to a thin layer of graphene strip ring resonator on top. The cladding is assumed to be porous alumina on the top of the graphene strip, which enhances the interaction of the surface plasmon wave and the target molecules. Finite difference time domain analysis is used to systematically design the structure and to investigate the performance of the sensor. Our simulations show that the proposed structure has larger refractive index sensitivity and lower intrinsic quality factor with respect to the similar optical structure. It...
Investigation and modeling of the thermal conductivity of PP/clay nanocomposites and PP/MWCNT nanocomposites
, Article E-Polymers ; Dec , 2010 ; 16187229 (ISSN) ; Golzary, A ; Sharif University of Technology
2010
Abstract
In this study, polypropylene/clay nanocomposites were prepared by melt blending method and their thermal conductivity and the thermal conductivity of polypropylene/multi-wall carbon nanotube (MWCNT) nanocomposites were investigated and modeled. It is found that the thermal conductivity of the PP/Clay and PP/MWCNT nanocomposites is increased with increasing temperature. The thermal conductivity of the nanocomposites is improved due to incorporation of nanoclay and MWCNT compared with pure PP matrix
Toward a collaborative method for knowledge management of software architectural decisions based on trust
, Article 12th International Conference on Fuzzy Systems and Knowledge Discovery, 15 August 2015 through 17 August 2015 ; 2015 , Pages 828-834 ; 9781467376822 (ISBN) ; Moaven, S ; Habibi, J ; Alidousti, R
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
Design and implementation of Architecture is a knowledge-driven process. Evaluation and verification the knowledge, in order to ensure its quality, have important role in improving overall design process. Furthermore, Architectural decision making is a complex and multi-criteria decision making problem in which multiple stakeholders make decisions from their perspectives causing overlaps and conflicts in the adopted decisions. Therefore, the requirement for strategies to manage these issues and also to improve coordination and cooperation among the various stakeholders to improve the overall process design is necessary. In this regard, there have been several activities that focus on...
Spatial integration by a dielectric slab and its planar graphene-based counterpart
, Article Optics Letters ; Volume 42, Issue 10 , 2017 , Pages 1954-1957 ; 01469592 (ISSN) ; Khavasi, A ; Sharif University of Technology
2017
Abstract
In this contribution a new approach to perform spatial integration is presented using a dielectric slab. Our approach is indeed based on the fact that the transmission coefficient of a simple dielectric slab at its mode excitation angle matches the Fourier-Green's function of first-order integration. Inspired by the mentioned dielectric-based integrator, we further demonstrate its graphene-based counterpart. The latter is not only reconfigurable but also highly miniaturized in contrast to the previously reported designs [Opt. Commun. 338, 457 (2015)]. Such integrators have the potential to be used in ultrafast analog computation and signal processing. © 2017 Optical Society of America
Idiosyncratic return volatility and the role of firm fundamentals: A cross-country analysis
, Article Global Finance Journal ; Volume 50 , 2021 ; 10440283 (ISSN) ; Hoseinzade, S ; Sharif University of Technology
Elsevier B.V
2021
Abstract
We investigate the relation between fundamental idiosyncratic volatility and stock returns idiosyncratic volatility using data from 56 countries. We find a strong positive relation between fundamental idiosyncratic volatility and idiosyncratic volatility of returns. This association, however, seems to be entirely concentrated in the developed economies, and we find no effect in the emerging markets. Specifically, fundamental idiosyncratic volatility does not lead to more idiosyncratic return volatility in countries with poor legal institutions and weak shareholder protection laws. © 2021 Elsevier Inc
Optimal model of solid waste technology assessment
, Article 2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005, Orlando, FL, 5 November 2005 through 11 November 2005 ; Volume 2005 , 2005 , Pages 69-76 ; 0791842185 (ISBN); 9780791842188 (ISBN) ; Saboohi, Y ; Sharif University of Technology
2005
Abstract
Review of waste management models indicate that optimization models based on the chain of waste flow are developed and applied in waste management systems. These models do represent the flow of material through few stages and they lack an integrated approach that may include the flow of material from the point of waste generation in different sectors till the end point at the land fill. It is also argued that the existing models do rarely consider the interrelated issues of economics, environment and social aspects. This conclusion has been followed by the development of an integrated multi stage and multi period dynamic model of waste flow based on quasi dynamic optimization techniques. The...
Using sliding mode control to adjust drum level of a boiler unit with time varying parameters
, Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 5 , 2010 , Pages 29-33 ; 9780791849194 (ISBN) ; Bakhtiari Nejad, F ; Saffar Avval, M ; Alasty, A
2010
Abstract
Stable control of water level of drum is of great importance for economic operation of power plant steam generator systems. In this paper, a linear model of the boiler unit with time varying parameters is used for simulation. Two transfer functions between drum water level (output variable) and feed-water and steam mass rates (input variables) are considered. Variation of model parameters may be arisen from disturbances affecting water level of drum, model uncertainties and parameter mismatch due to the variant operating conditions. To achieve a perfect tracking of the desired drum water level, two sliding mode controllers are designed separately. Results show that the designed controllers...