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Analysis of PlasMOStor in CMOS Compatible Plasmonic Circuits
, M.Sc. Thesis Sharif University of Technology ; Mehrany, Khashayar (Supervisor)
Abstract
Thus far numerous components and devices have been designed and realized based on plasmonics. Hereon, we focus on PlasMOStor which is probably the first and most important CMOS compatible plasmonic modulator. It resembles to its electronic counterpart MOS transistor in geometry, unless, it has a plasmonic waveguide instead of the regular channel to modulate optical signals . By applying voltage to the gate and inset of charge carrier accumulation, optical properties of the channel changes and plasMOStor turns off. In this thesis, we carry out a through investigation of plasMOStor’s operation. We show that the proposed theoretical description of plasMOStor is fallacious. Subsequently,...
Fast content based color image retrieval system based on texture analysis of edge map
, Article Advanced Materials Research, 8 July 2011 through 11 July 2011 ; Volume 341-342 , July , 2012 , Pages 168-172 ; 10226680 (ISSN) ; 9783037852521 (ISBN) ; Zamani, F ; Jamzad, M ; Sharif University of Technology
2012
Abstract
In this paper we propose a method for CBIR based on the combination of texture, edge map and color. As texture of edges yields important information about the images, we utilized an adaptive edge detector that produces a binary edge image. Also, using the statistics of color in two different color spaces provides complementary information to retrieve images. Our method is time efficient since we have applied texture calculations on the binary edge image. Our experimental results showed both the higher accuracy and lower time complexity of our method with similar related works using SIMPLIcity database
A heuristic scheduling method for the pipe-spool fabrication process
, Article Journal of Ambient Intelligence and Humanized Computing ; Volume 9, Issue 6 , 2018 , Pages 1901-1918 ; 18685137 (ISSN) ; Shadrokh, S ; Salehian, A ; Sharif University of Technology
Springer Verlag
2018
Abstract
The pipe-spool fabrication process is a critical operational section in the piping projects that usually used to accelerate and discipline the installation process, especially, when we have a particular deadline for the project. For this reason, the fast and optimal scheduling of the fabrication activities with considering the real conditions and using manual or traditional methods is a significant problem for the decision-makers. In this paper, we use a novel linear programming model to schedule the spool fabrication activities based on the flexible job shop scheduling problem (FJSP). Because FJSP is a challengeable NP-hard problem, we solve the proposed mathematical model with a heuristic...
Leukocyte's nucleus segmentation using active contour in YCbCr colour space
, Article Proceedings of 2010 IEEE EMBS Conference on Biomedical Engineering and Sciences, IECBES 2010, 30 November 2010 through 2 December 2010, Kuala Lumpur ; 2010 , Pages 257-260 ; 9781424476008 (ISBN) ; Jahed, M ; Salehian, P ; Eslami, A ; Sharif University of Technology
2010
Abstract
Blood cell segmentation is a crucial part of many medical and laboratory procedures such as cell counting and blood cell disorder diagnosis. Among different types of blood cells, white blood cells are the most important clinically, as they suffer greatest from blood disorders. In this paper we propose a method for automatic segmentation of white blood cells nucleus. A distinctive function is used in YCbCr color space to segment the white blood cells nucleus. Next, the sub-images are extracted which contain the whole body of white blood cell nucleus. Then an active contour method is applied to the sub-images extracted from the previous step to accurately segment the cell nucleus boundary. Our...
An Image Processing Algorithm for Diagnosis of Cell Samples
, M.Sc. Thesis Sharif University of Technology ; Jahed, Mehran (Supervisor) ; Salehian, Pirouz (Supervisor)
Abstract
Detection of blood diseases is one of the hardest branches of medical science. The human circulatory system mainly consists of three main components namely white blood cells, red blood cells and platelets. Many diseases are diagnosed based on qualitative and quantitative evaluation of these cells, such as cell’s quantity, size, shape and the color of the cells. For example, AIDS and blood cancer cause major changes in components of immune system i.e. white blood cells. Also, some features of red blood cells change in various diseases such as iron deficiency, anemia, thalassemia and other diseases like malaria. Rapid diagnosis and treatment of these diseases has a considerable impact on the...
Evaluation of the Performance of Polyacrylonitrile Membrane Modified with TiO2@MIL-88A (Fe) Photocatalyst for Humic acid Removal in Photocatalytic Membrane Reactor under Visible Light
, M.Sc. Thesis Sharif University of Technology ; Fotovat, Farzam (Supervisor) ; Musavi, Abbas (Supervisor)
Abstract
Membranes are one of the best water and wastewater treatment methods that could successfully replace other less-effective conventional techniques such as adsorption, coagulation, etc. Moreover, relative to other techniques, the quality of the water produced by membrane separation is very high compared to others. One of the main drawbacks of membrane treatment is fouling of the surface and internal pores of the membranes restricting its widespread application in the industry.In this study, TiO2@MIL-88A (Fe) photocatalyst and polyacrylonitrile membrane were modified with this photocatalyst to remove humic acid under visible light irradiation inside the PMR photocatalytic reactor was...
Photocatalytic TiO2@MIL-88A (Fe)/polyacrylonitrile mixed matrix membranes: Characterization, anti-fouling properties, and performance on the removal of natural organic matter
, Article Chemosphere ; Volume 302 , 2022 ; 00456535 (ISSN) ; Mehdipour, M. H ; Fotovat, F ; Mousavi, S. A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Photocatalytic membrane reactors (PMRs), coupling photocatalysts and membranes in a single system, have shown a considerable potential to reduce membrane fouling, which is one of the major drawbacks of using membranes to treat water and wastewater. In this study, the visible light-activated photocatalysts were incorporated into the polyacrylonitrile (PAN) casting solution to synthesize the photocatalytic composite membranes. The physicochemical properties and the morphology of the membranes and photocatalysts were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction analysis (XRD), ultraviolet–visible diffuse reflectance...
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...
Fabrication and performance of polysulfone/H2O2-g-C3N4 mixed matrix membrane in a photocatalytic membrane reactor under visible light irradiation for removal of natural organic matter
, Article Separation and Purification Technology ; Volume 285 , 2022 ; 13835866 (ISSN) ; Heydari, H ; Khansanami, M ; Vatanpour, V ; Mousavi, S. A ; Sharif University of Technology
Elsevier B.V
2022
Abstract
The coupling of photocatalysis with membrane technology, which is known as photocatalytic membrane reactors (PMRs), has received great consideration in recent years and become a promising approach with the high potential to improve the fouling of membranes. In this paper, the photocatalyst of g-C3N4 treated with H2O2 was incorporated with a polysulfone membrane to enhance the anti-fouling properties of the membrane. AFM, FE-SEM images, porosity, and contact angle analysis indicated that the membrane properties like hydrophilicity, porosity, and surface roughness were improved. Also, UV–visible DRS, PL spectra, EIS analysis confirmed that the treated g-C3N4 (H2O2-g-C3N4) had high light...
A study on Warm Rolling Behavior of an Austenitic Stainless Steel and the Mechanical Properties of the Rolled Product
, M.Sc. Thesis Sharif University of Technology ; Serajzade, Siamak (Supervisor)
Abstract
In this study, thermo-mechanical behavior of an austenitic stainless steel AISI316L was investigated using mathematical modeling and experimental analysis during warm rolling process. First, the thermo-mechanical analysis was carried out employing the finite element software, Abaqus CAE, to assess temperature, strain, velocity and stress distribution during rolling. Then, rolling operations on 316L austenitic steel were performed under different working conditions while mechanical testing as well as microstructural observations were made on the rolled steels. Using simulation results and practical data, microstructural events and mechanical properties after warm rolling of stainless steel...
Prediction of Temperature and Strain Distribution in the Warm Rolling of Austenite Stainless Steel
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this research, the hot and warm rolling of stainless steel 304 was studied. First the rolling process was simulated using Finite Element Method software ABAQUS and the distribution of temperature and strain in the process under discontinuous conditions were predicted. Next, hot and warm rolling of stainless steel 304 under different conditions was carried out. Specimens were cut and subject to mechanical testing, metallography and electron microscopic studies. Data obtained from these experiments and the predicted trends from ABAQUS were compared, therefore studying the effect of different parameters on the microstructure and mechanical properties of the rolled specimen. Results indicate...
Theoretical and Experimental Investigation of Warm Rolling of Al Alloy 2017
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
A mathematical model was developed to assess thermomechanical behavior of work rolls during warm rolling processes of AA2017. A combined finite element analysis-slab method was first developed to determine thermal and mechanical responses of the strip being rolled under steady-state conditions; Then, the calculated roll pressure and temperature field were utilized as the governing boundary conditions for the thermomechanical problem of the work roll. Finally, the thermomechanical stresses within the work rolls were predicted by a thermoelastic finite element approach. The results indicate that, in warm strip rolling, thermal and mechanical stresses developed in the work rolls are comparable....
Thermo-mechanical Simulation of Warm Rolling of 6061 Al Alloy Using Finite Element and Upper Bound Methods
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this research, temperature distribution and roll force during steady state warm and hot rolling of 6061 Al alloy strip have been simulated, using finite element method and upper bound solution. At first, the velocity field and deformation zone shape have been determined, by means of upper bound solution, then using 2D finite element method, the temperature distribution within rolling and considering rate of heat of deformation, has been calculated. This model generalized for two pass steady state warm and hot rolling. Also, in order to evaluate the predictions, the experimental recorded of temperature variation, during hot rolling and temperature variation predicted by model has been...
Simulation of Non-isothermal Austenite to Ferrite Transformation by Using Cellular Automaton Method
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this study, transformation of austenite to ferrite under continuous cooling condition of a low carbon steel was investigated. In the first step, a heat transfer model was employedconsidering governing heat transfer boundary conditions and a microstructure model based on Cellular Automaton method was used simultaneouslyto predict austenite to ferrite transformation progress. The influence of pre-heating temperature and primary austenite grain size on the final ferrite grain size and distribution were perdected. To verify the simulation results, experimental processes were utilized. The microstructure distribution was determined by means of Clemex Pro software then, these results were...
Study of Microstructure and Mechanical Properties of Austenitic Stainless Steel after Sheet Rolling Process
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
Austenite in the 300 stainless steels is not a table phase in deformation processing during which martensite phase forms. This causes significant changes in the microstructures as well as the mechanical properties of deformed steel. In this work, the effects of rolling speed, reduction, temperature and strain pass on the strain-induced martensite during strip rolling operation of stainless steel 304L are studied. Cold rolling experiments under different speeds, reduction and temperature are conducted and then, the microstructural events and mechanical properties of the rolled steel are evaluated. For doing so, different testing techniques including tensile test, hardness measurement, optical...
Softening Kinetics Prediction of Cold Worked Aluminum Alloy
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this work, annealing procedure of cold-deformed AA5052-SiC composite has been simulated by using cellular automata approach and the effect of SiC second phase on softening kinetics has been studied. To do so, site saturated nucleation has been employed to establish initial microstructure. In addition, topological changing due to deformation has been implemented on the microstructure. During annealing, recovery and recrystallization phenomena occur simultaneously, and it has strong effect on the annealed microstructure. Therefore, during annealing, recrystallization and recovery has been considered simultaneously and decreasing in the stored energy, which has developed during deformation...
Investigation on Thermo-mechanical Behavior of AA5086 During Warm and Hot Rolling Operation
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
A mathematical model has been proposed to estimate the deformation pattern and the required power in cold plate rolling using the stream function method and upper bound theorem. In the first place admissible velocity distributions as well as the geometry of deformation zone were derived from the proposed stream functions. Then, the optimum velocity field was obtained by minimization of the power function computed based on the upper bound theorem. Then a steady state heat transfer equation has been solved in whole model using finite element method. In order to verify the predictions, rolling experiments on aluminum plates were conducted and also, a finite element analysis performed employing...
Theoretical and Experimental Investigations of Deformation Behavior from Stainless Steel 304L During Rolling at Evelated Temperatures
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)Effect of Strain Path on Static Recrystallization Behavior of a Steel
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
Static recrystllization in low carbon steel after two type of deformation –sidepress as an inhomogeneous deformation and rolling as a common industrial process - has been simulated using Cellular Automata (CA). The finite element method was utilized to compute the strain and stored energy distribution due to deformation. The initial microstructures were created by simulation of recrystallization with homogeneous site-saturated nucleation and topologic deformation was also considered in model. Subsequently using the result of FEM, stored energy of deformation was calculated and transferred into a two dimensional CA lattice. Nucleation rate and grain boundary velocity were considered...
High Temperature Deformation and Creep-Aging Behavior of an Aluminum Alloy 5083
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
Mechanical behavior of aluminum-magnesium alloy, AA5083, was studied at high temperatures using hot tensile testing together with uniaxial creep experiments. In the first place, the as-received AA5083 sheet was subjected to annealing heat treatment to remove the effect previous plastic straining. Then, creep experiments were conducted at temperatures in the range of 190°C to 300 ° C under constant the stress varied between 30 MPa to 100 MPa. The hot tensile testing was also carried out from room temperatures up to 400 °C under nominal constant strain rates of 0.0005, 0.005, 0.01 and, 0.05 (1/s). In addition to the mechanical testing, optical metallography and scanning electron microcopy were...