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    Fabrication of Mn/Co and Co Coatings on AISI 430 for SOFC Interconnect Via Sol-Gel and Dip Coating

    , M.Sc. Thesis Sharif University of Technology Dayaghi, Amir Masoud (Author) ; Askari, Masoud (Supervisor)
    Abstract
    With regard to recent progress in decreasing of operating temperature of Solid Oxide Fuel Cell (SOFC), metallic interconnect use widely than ceramic interconnect. Metallic interconnect have interested due to their low cost, easy fabrication and high electronic and thermal conductivity.oxidation resistance of metals is big challenge, because of low conductivity of formed oxide layers that led to increasing of electrical conductivity. Ferritic stainless steel is among the most thriving candidate alloy because of BCC structure that its coefficient of temperature expansion is close to that of other SOFC. Nonetheless, the increase of electrical resistance over the time and the evaporation of... 

    Lithium Concentration from Brines Using Electrodialysis

    , M.Sc. Thesis Sharif University of Technology Zarean, Amir Reza (Author) ; Askari, Masoud (Supervisor)
    Abstract
    In the present study, the concentration of lithium in Iranian brines was investigated and studied using the electrodialysis method. First, the desired electrodialysis cell and unit were designed and fabricated. Then, by performing electrodialysis tests on three different samples of artificial brines with varying ion concentrations, the best and most suitable concentration for use in the process was determined. Then, in the two sections of experimental and designed experiments using Minitab software and the full factorial method, the concentration and separation of lithium ions from monovalent and divalent cations present in brines were examined. The results indicate that at medium voltages... 

    Determination of Solubility and Density in Acidic Gas Absoption Systems by Ionic Liquids by Means of Cubic Equations of State

    , M.Sc. Thesis Sharif University of Technology Askari, Amir Ashkan (Author) ; Ghotbi, Cyrus (Supervisor) ; Jalili, Amir Hossein (Supervisor)
    Abstract
    Due to their low volatility, negligible flammability, and high regeneration capacity, ionic liquids have attracted a lot of attention in chemical and process engineering fields. Regarding the limited access to the laboratory facilities, developing theoretical methods such as equations of state is important in this research field. Thus, data for density and viscosity of pure ionic liquids and vapor pressure data for binary mixtures of ionic liquids and acidic gas have been collected and validated from the IL Thermo website for 42 ionic liquids. By consideration of theoretical studies and comparison of the performance of different cubic equations of state in predicting the aforementioned... 

    Non-linear assessment of tunable vibrating ring micro-gyroscopes design

    , Article Mechanics Based Design of Structures and Machines ; 2023 ; 15397734 (ISSN) Sayyaadi, H ; Mokhtari Amir Majdi, M. A ; Askari, A. R ; Sharif University of Technology
    Taylor and Francis Ltd  2023
    Abstract
    This paper introduces a tunable design for an electrically actuated vibrating ring micro-gyroscope. This mechanism contains eight piezoelectric micro-beams attached to the vibrating ring in each drive and sense directions. Employing a full geometric non-linear model for the vibrating ring and accounting for the micro-beam’s mid-plane stretching; the mathematical model associated with the present system is obtained. Afterward, utilizing the Hamilton principle together with the Ritz method, the reduced equations of motion are derived. The present results are validated by those available in the literature for simpler systems. A three-dimensional (3D) finite element (FE) simulation was carried... 

    Sustainable-Resilient Supplier Selection Through Fuzzy Multi-Criteria Decision Making Approaches

    , M.Sc. Thesis Sharif University of Technology Varchandi, Sahar (Author) ; Akbari Jokar, Mohammad Resa (Supervisor) ; Memari, Ashkan (Co-Supervisor)
    Abstract
    Today, with the expansion of business relations at international levels, there are many organizations that operate in global supply chains. Activities at such levels face new types of challenges in various fields of "supply chain management" pillars, of which "supplier selection" is one of them. The possibility of unexpected events, the need to comply with environmental protection laws, as well as the need to take into account social considerations, are among the things that have increased by being in larger supply chains, making it challenging to provide the basic resources needed in such chains and forcing their managers to considering considerations other than what they have always... 

    Cancer Detection and Classification in Histopathology Images Under Small Training Set

    , M.Sc. Thesis Sharif University of Technology Askari Farsangi, Amir Hossein (Author) ; Rohban, Mohammad Hossein (Supervisor) ; Sharifi Zarchi, Ali (Supervisor)
    Abstract
    Histopathology images are a type of medical images that are used to diagnose a variety of diseases. One of these illnesses is the Leukemia cancer, which has four different subtypes and is diagnosed using a blood smear image. As a result of the advancement of deep learning tools, models for diagnosing various types of disease from images have been developed in recent years.In this project, one of the best models developed to diagnose four different types of disease was replicated, and it was demonstrated that, while this model achieves acceptable accuracy, its decision is not based on medically significant criteria. In the following, a general method for diagnosing the disease is proposed... 

    Two-and three-dimensional numerical simulations of supersonic ramped inlet

    , Article Scientia Iranica ; Volume 25, Issue 4 , 2018 , Pages 2198-2207 ; 10263098 (ISSN) Askari, R ; Soltani, M.R ; Sharif University of Technology
    Sharif University of Technology  2018
    Abstract
    Two-dimensional (2D) and three-dimensional (3D) numerical simulations of an external compression supersonic ramped inlet are presented for a free stream Mach number of 2. A comparison made between numerical results and experimental data showed that multi-block structured gird using standard k - " turbulence model gives acceptable results. The shape of present inlet diffuser was transformed gradually into a circular one to encompass the Aerodynamic Interface Plane (AIP). It was observed that the 3D simulation predicted a more accurate static pressure distribution during the length of supersonic inlet and total pressure distribution at the AIP in comparison with the 2D one. Further, a better... 

    Optimized Fabrication of Spinel Nanao Powder Mn1.5Co1.5O4 Through Sol-Gel Method Applicable to Solid Oxid Fuel Cell

    , M.Sc. Thesis Sharif University of Technology Hashemi, Tahereh (Author) ; Askari, Masoud (Supervisor)
    Abstract
    Nowadays, too much attention has been paid to Solid Oxide Fuel Cells (SOFC). One of the key components in SOFC is interconnect which plays an important role in SOFC performance. Interconnect can be either a metallic or ceramic layer that sits between each individual cell. The reduction in operating temperature of SOFC resulted in interests in using metallic interconnectors. However, the oxidation of these metallic materials is big challenge. Chromium (Cr), Nickel (Ni) and Iron (Fe) alloys have been employed to overcome this deficiency. However, these alloys bring another difficulty which is the presence of active elements such as Cr which reduces the performance of interconnects by forming... 

    Fabrication of Silicon Nanowires with various Silicon Substrates and Investigation of the structural Properties and their Behavior

    , M.Sc. Thesis Sharif University of Technology Teymouri, Arastoo (Author) ; Askari, Masoud (Supervisor)
    Abstract
    In this thesis, Silicon nanowires were synthesized using carbothermal method via Vapor-Liquid-Solid mechanism catalyzed by gold nanoparticles deposited on various substrates. Silicon nanowires just grew on (100) and (111)-oriented silicon substrates. For a particular set of process parameters, we observed a critical thickness of the nucleating gold film, that had depened on a kind of various substrates. We studied the dependence of the Au-Si alloy droplet size and size distribution on the starting gold film thickness and the annealing conditions. We used a modified heating sequence that deconvoluted the effect of various substrates consumption and gas-phase silicon supply on the Au-Si alloy... 

    Copper Selective Leaching from Sarcheshmeh Reverberatory Furnace Dusts

    , M.Sc. Thesis Sharif University of Technology Mohagheghi, Mahdi (Author) ; Askari, Masoud (Supervisor)
    Abstract
    In this study, leaching of Sarcheshmeh Reverberatory Furnace Dust was investigated in the H2SO4-O3 media. Response surface methodology based on central composite face-centered design (RSM-CCF), was applied to optimize the operating parameters. The optimum conditions to obtain the main goal of maximum copper and minimum iron dissolution from dust were identified to be temperature of 30˚C, leaching time of 3hr, initial pH of 0.5, pulp density of 20% and ozone flow rate of 1g/h. The copper and iron concentrations of leaching solution were found to be 27.11 and 0.89983 g/L under the optimum conditions, respectively. The results showed that selective copper extraction from the dust could be... 

    Solid State Reduction of Iran Titanomagnetites to Extract TiO2 & Fe

    , M.Sc. Thesis Sharif University of Technology Poyanfar, Soroush (Author) ; Askari, Masoud (Supervisor)
    Abstract
    Titanomagnetites are resources of iron and titanium. high level of titanium in titanomagnetites makes using them in iron making processes very difficult. In this work an attempt was made to produce an iron bearing and a titanium bearing product using solid state reduction of Fanouj mine titanomagnetite concentrate. For this purpose, the concentrate was reduced using coal and then was subjected to magnetic separation. In this work, effect of temperature, time, added coal amount, and additive amount on reduction was studied. The result showed that the optimum conditions are 1325 celsius degree, 2.5 hours, 25 percent added coal and 2 percent additive. In optimum conditions a magnetic product... 

    Influence of Cobalt and Vanadium Dopants on the Performance of TiO2(B) Nanowires used as anode Materials in Lithium-ion Batteries

    , M.Sc. Thesis Sharif University of Technology Amirsalehi, Mahmoud (Author) ; Askari, Masoud (Supervisor)
    Abstract
    Li-ion batteries have been widely applied as power sources for portable electronic devices. Recently, Li-ion batteries are considered as the most promising energy storage technology for electric vehicle applications however, fundamental improvements are needed. TiO2 (B) is attractive candidate for anodes in rechargeable Li-ion batteries, due to their low cost, non-toxicity and favorable channel structure for fast lithium mobility. It is predicted that synthesis of doped nanostructure of this material, through reducing the diffusion pathway and formation of crystal defects, will increase the capacity of TiO2(B). In this investigation, Co and V doped TiO2(B) nanowires are synthesized by... 

    Low Temperature Metallic Foams

    , M.Sc. Thesis Sharif University of Technology Foroughi, Leila (Author) ; Askari, Masoud (Supervisor)
    Abstract
    Metal foams are considered as a group of new materials and are applied widely in various areas due to their particular properties such as low density, high strength-to-weight ratio and appropriate mechanical, thermal, physical, electrical and magnetic properties. The aim of the present study is acquiring the technical knowledge of Zinc foam production by melting route and also optimizing the effective parameters on the foam stability. For this reason, 4 Zinc foams were produced at different times and temperatures. The amount of Calcium as the melt fluidity reducing agent and Titanium hydride and Zinc carbonate as the blowing agent were the same in all the specimens. The effect of heat... 

    Iron Removal from Copper Electrowinning Procces

    , M.Sc. Thesis Sharif University of Technology Hosseini, Farzaneh (Author) ; Askari, Masood (Supervisor)
    Abstract
    Iron is a common impurity in copper minerals. The presence of iron in hydrometallurgical copper PLS causes continuous reactions between Fe(II) and Fe(III) ions. In order to improve energy efficiency and product quality iron removal shall be done. In this study separation of iron from Sarcheshme copper leaching liquor containing 6 g/L Fe, was conducted by solvent extraction using D2EHPA in kerosene. Chloric acid solution was used to strip the loaded iron from organic phase. Results of extraction experiments designed by taguchi method showed 92.49% iron recovery and 2.44% copper extraction under optimum condition. Using same method for stripping experiments, it was found that variation of time... 

    Study the Effect of Carbon Content Exist in Midrex Cold Briquetted Sponge Iron on Melting Performance and Comparison with DRI and HBI

    , M.Sc. Thesis Sharif University of Technology Ranjbar, Hassan (Author) ; Askari, Masoud (Supervisor)
    Abstract
    Midrex sponge iron is an active product and there are several problems with store and export it.Cold briquetting sponge iron method is a new method to protect sponge iron from oxidation and provides the possibility of its storage and transportation. Iran as one of the biggest countries that produce sponge iron, has a lot of sponge iron pilots that equipped with cold briquetted machines,but their production capacity is limited and is about 5 percent of their production capacity. With regard to no need for country to these amount of sponge iron, most of these pilots have to store and transport large volumes of sponge iron and the risk of oxidation and fire threatens these units.By using cold... 

    Study on Nucleation and Growth of Titanium Dioxide Nano Particles via Gel-Sol Method

    , M.Sc. Thesis Sharif University of Technology Shahini, Sharif (Author) ; Askari, Masoud (Supervisor)
    Abstract
    Nanotechnology is an efficient method suitable for fabrication and production of minimal single dimensional nanometric structures. Such materials and systems can be logically designed that lead to new and optimized biological, chemical and physical properties and characteristics due to their size. Nucleation and growth –appearance of a new phase out of an old phase – is a ubiquitous phenomenon in nature. Fundamental understanding of nanoparticles nucleation and growth mechanism allows more control on form, size and composition and allows tuning of the above said properties easily with use of different reactive conditions as a result of this ability . Nanoparticles of titania are one of... 

    Feasibility and Performance Analysis of a Thermoacoustic Heat Pump

    , M.Sc. Thesis Sharif University of Technology Askari, Rasoul (Author) ; Ghorbanian, Kaveh (Supervisor)
    Abstract
    Thermoacoustics deals with the conversion of heat energy into sound energy and vice versa. This new and emerging technology has a strong potential towards the development of sustainable and renewable energy systems by utilizing waste heat or solar energy. Although thermoacoustic devices are simple to fabricate; however, the design process is very challenging. The thermoacoustic phenomenon is discovered over a century ago; nevertheless, the rapid advancement in this field occurred during the past three decades when the theoretical understanding of the phenomenon is developed along with the prototype devices. There are several advantages of heat engines and refrigerators based on... 

    Assortment Optimization with Demand Learning for Reusable Products

    , M.Sc. Thesis Sharif University of Technology Askari, Faezeh (Author) ; Modarres, Mohammad (Supervisor)
    Abstract
    One of the lesser-known issues in the modeling literature of assortment optimization issues is the assortment optimization for reusable products, which is an issue in various areas, including offering parking space, renting cloud computing systems resources, and rental of fashion products, etc.In this issue, we are faced with a high diversity product rental store that has a customer in each period. The seller offers a limited set of products depending on the customer demand and the inventory in hand. He can decide to rent the product or leave the system without renting the product. In case of renting the products by the customer, he may return them until the end of this period or keep them... 

    Recovery of Vanadium from Leaching Solution of Roasted Isfahan Steelmaking Slag Using Solvent Extraction

    , M.Sc. Thesis Sharif University of Technology Mousavi, Reza (Author) ; Askari, Masoud (Supervisor)
    Abstract
    Solvent extraction of vanadium (V) from sulfated leaching solution of the converter slag of the Isfahan steel company followed by stripping of this element from the organic solvent were examined in this study. In the experimental section, 2-ethyl-1-hexanol extractor was utilized for selective separation of V(V) from the acidic medium containing Si, Na, Fe, Al, Ca, and P ions. Ammonium chloride solution was also used for stripping V from the organic phase. Under optimal condition (pH=1.9, T=65℃, extractor concentration of 68% and organic phase volume fraction of 0.66), 91% was extracted in solvent extraction stage. Under optimal stripping conditions (pH=7.5, T=25℃, organic phase volume... 

    Modeling of Epistemic Uncertainties in Seismic Hazard Analysis Based on Reliability Methods

    , M.Sc. Thesis Sharif University of Technology Askari, Mohammad (Author) ; Mahsouli, Mojtaba (Supervisor)
    Abstract
    The primary objective of this thesis is comprehensive treatment of epistemic uncertainties in probabilistic seismic hazard analysis based on structural reliability methods. The classical methods of probabilistic seismic hazard analysis, i.e., PSHA, traditionally consider a limited number of uncertainties. The ones that they do consider comprise the aleatory uncertainty in the magnitude, the distance, and the residuals of ground motion prediction equations and the epistemic uncertainty in the intensity measures predicted by different such equations. However, there are many sources of epistemic uncertainty that, according to past studies, have a significant impact on the upper tail of the...