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    Digiatal Holographic Microscopy

    , M.Sc. Thesis Sharif University of Technology Safari Taghoustani, Jamal (Author) ; Seyed Reihani, Nader (Supervisor)
    Abstract
    Digital holographic microscope is a microscope based on interferometry, which allows us to simultaneously have the information of the phase in addition to the intensity information. In this research, we intend to measure the thickness of the red blood cell with the help of an interferometer and prepare a three-dimensional microscopic image of the blood cell. After contamination, a laser beam hits an optical beam splitter that can divide the light into two parts with equal intensities. Each of these wave fronts, after hitting the mirror, is directed to another beam splitter to be recombined. . Since the incident lights have traveled different optical paths, they have a phase difference with... 

    The effect of FSW parameters on the macro/micro-galvanic corrosion of the dissimilar joint between AZ31 and AA5052

    , Article Materials Chemistry and Physics ; Volume 305 , 2023 ; 02540584 (ISSN) Safari, S ; Nouripour, M ; Ghorbani, M ; Safari, H ; Sharif University of Technology
    Elsevier Ltd  2023
    Abstract
    In this study, dissimilar friction stir welding was performed between AA5052 aluminium and AZ31 magnesium alloys using a variety of parameters. The results revealed that the optimal range of welding parameter is between 20 and 38 rpm/mm.min−1 (the ratio of rotation speed to travel speed). The findings of the X-ray diffraction and Micro-hardness tests on the stir zone indicated that when the rotation speed is increased, it leads to the formation of intermetallic compounds such as Al12Mg17 and Al3Mg2. The polarization test was used to assess the corrosion rate in various zones. The corrosion rate in the stir zone is higher than in other zones due to macro-galvanic couple between Al and Mg.... 

    Hyper-T-width and hyper-D-width: Stable connectivity measures for hypergraphs

    , Article Theoretical Computer Science ; Volume 463 , 2012 , Pages 26-34 ; 03043975 (ISSN) Safari, M ; Sharif University of Technology
    2012
    Abstract
    We introduce hyper-D-width and hyper-T-width as the first stable (see Definition 3) measures of connectivity for hypergraphs. After studying some of their properties and, in particular, proposing an algorithm for computing nearly optimal hyper-T-decomposition when hyper-T-width is constant, we introduce some applications of hyper-D-width and hyper-T-width in solving hard problems such as minimum vertex cover, minimum dominating set, and multicut  

    Appropriate Methods of River Quality Restoration

    , M.Sc. Thesis Sharif University of Technology Ikani, Nima (Author) ; Hashemian, Jamal (Supervisor)
    Abstract
    The practice of river restoration has grown exponentially over the last several decades. There has been little empirical evaluation of whether restoration projects individually or cumulatively achieve the legally mandated goals of improving the structure and function of rivers. Nutrient reduction through simple methods is the most critical factor. The simplest method, which has minimal financial burden as well as preventing, and reducing the entrance of pollutants into the Chalus River (Mazandaran, in north of Iran), has been selected. The origins of rivers start at a high point and move with a steep. ... 

    Analysis and Optimization of a Two-stage Light Gas Launcher for Shock Consolidation Process

    , M.Sc. Thesis Sharif University of Technology Mohammadi, Mohsen (Author) ; Arghavani Hadi, Jamal (Supervisor)
    Abstract
    Powder metallurgy is one of the most important and most usable methods in industries. Nowadays, many of the specimens are made this way. In this method, after powder compaction stage, because of sintering in high temperature, crystallographical structure of the material changes. This change results in poorer strength than initial powde. In order to avoid change and decrease in powder strength, shock consolidation is used. In this research, because of complication of this phenomenon and final quality of the specimen, shock consolidation of metal powders is investigated and analysed. This phenomenon is modeled, simulated, analysed and optimized mathematically.Various methods are used to create... 

    Assessment of Water and Sewage Facilities of Kish Island and Offering Solutions in Emergency Conditions (A Case Study on Kish Island)

    , M.Sc. Thesis Sharif University of Technology Mojtahedi, Amir (Author) ; Hashemian, Jamal (Supervisor)
    Abstract
    Vulnerability of water and sewage infrastructure in Kish Island survey versus natural and unnatural threats. It is important to know what to do when crisis or unpredicted event occurs in the Island. Decision makers and master managers of the Island, as the main custodians make suitable and effective reactions and decisions so that the impact of threats is reduced to minimum. According to the threats, there are short term and long term solutions. These solutions can be applied when the Island is encountered with crisis  

    Investigating the Reduction of Sewage Sludge Volume in Kish slandRefineries with the Help of Mud Eating Worms

    , M.Sc. Thesis Sharif University of Technology Heidari, Moosa (Author) ; Hashemian, Jamal (Supervisor)
    Abstract
    A major environmental challenge for wastewater treatment in Iran and other countries is the disposal of excess sludge produced during the biological process. This project has been developing and testing a technology that will help to overcome this challenge in Kish Island wastewater plant. Results demonstrate it can perform highly effective treatment of municipal wastewater while producing low levels of sludge.Applicationofvermifiltrationfor treatment of wastewater sludge using the Eiseniafetida earthworm species. The earthworms’ gut acted as a biofilter whereby there was reduction in the sewage wastewater’s solid and liquid organic and inorganic wastes through ingestion and expelling these... 

    Microstructure evolution and its influence on deformation mechanisms during high temperature creep of a nickel base superalloy

    , Article Materials Science and Engineering A ; Volume 499, Issue 1-2 , 2009 , Pages 445-453 ; 09215093 (ISSN) Safari, J ; Nategh, S ; Sharif University of Technology
    2009
    Abstract
    The interaction of dislocation with strengthening particles, including primary and secondary γ′, during different stages of creep of Rene-80 was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). During creep of the alloy at 871 °C under stress of 290 MPa, the dislocation network was formed during the early stages of creep, and the dislocation glide and climb process were the predominant mechanism of deformation. The density of dislocation network became more populated during the later stages of the creep, and at the latest stage of the creep, primary particles shearing were observed alongside with the dislocation glide and climb. Shearing of γ′... 

    Co-evolutionary reliability-oriented high-level synthesis

    , Article 2008 IEEE International Symposium on Circuits and Systems, ISCAS 2008, Seattle, WA, 18 May 2008 through 21 May 2008 ; 2008 , Pages 2026-2029 ; 02714310 (ISSN) ; 9781424416844 (ISBN) Safari, S ; Aminzadeh, S ; Sharif University of Technology
    2008
    Abstract
    The main contribution of this paper is utilizing bio-inspired evolutionary algorithm for reliability oriented high level synthesis. In this paper genetic algorithm is used to schedule a data-flow graph considering latency and resource allocation considering resource constraints and area overhead. Then a co-evolutionary strategy merges the results of these solutions to find the RT level design of the circuit which satisfies both performance and area constraints. To satisfy the user-defined reliability, another genetic algorithm is developed to insert some hardware redundancies to the resulted data-path. Experimental results show using the proposed approach results in an acceptable reliability... 

    On the heat treatment of Rene-80 nickel-base superalloy

    , Article Journal of Materials Processing Technology ; Volume 176, Issue 1-3 , 2006 , Pages 240-250 ; 09240136 (ISSN) Safari, J ; Nategh, S ; Sharif University of Technology
    2006
    Abstract
    Rene-80, as an alloy for production of the jet turbine blades, shows high mechanical properties as well as microstructure stability during the high temperature engine operation. In this study we tried to have a deep insight on the microstructure of the cast Rene-80 and the evolution of microstructure during the different stages of the relatively complex GE class-A heat treatment. Although the solution heat treatment homogenized the chemical alloy segregation resulted from the casting to some extent, it did not cause all the casting γ′ particles to dissolve completely in the matrix. Primary aging caused growth in the residue particles as well as growth of the new precipitated particles, which... 

    Inflammation and mental health disorders: immunomodulation as a potential therapy for psychiatric conditions

    , Article Current Pharmaceutical Design ; Volume 29, Issue 36 , 2023 , Pages 2841-2852 ; 13816128 (ISSN) Safari, H ; Mashayekhan, S ; Sharif University of Technology
    Bentham Science Publishers  2023
    Abstract
    Mood disorders are the leading cause of disability worldwide and their incidence has significantly increased after the COVID-19 pandemic. Despite the continuous surge in the number of people diagnosed with psychiatric disorders, the treatment methods for these conditions remain limited. A significant number of people either do not respond to therapy or discontinue the drugs due to their severe side effects. Therefore, alternative therapeutic interventions are needed. Previous studies have shown a correlation between immunological alterations and the occurrence of mental health disorders, yet immunomodulatory therapies have been barely investigated for combating psychiatric conditions. In... 

    Synthesis, Characterization, Crystal Structure Determination and Theoretical Studies of Some new Rhenium(I)-tricarbonyl Complexes with 2,2'-bipyridine and 2,9-dimethylphenanthroline Ligands

    , M.Sc. Thesis Sharif University of Technology Safari, Fatemeh (Author) ; Kia, Reza (Supervisor)
    Abstract
    The synthesis, characterization, structural and computational studies of mononuclear Re(I) tricarbonyl complexes of 2,2'-bipyridine (2,2′-bpy) and 2,9-dimethylphenanthtroline (2,9-Me2Phen), [Re(CO)3(NN)(X)], where NN=2,2′-bpy,X=Br (1) and X=–ONO (3); NN=2,9-Me2 Phen, X=Br (2) and X= –ONO (4), were reported. The complexes characterized by crystallographic and spectroscopic methods and elemental analyses. In each complex, the Re(I) center showed the distorted octahedral geometry. Single crystal X-ray diffraction data revealed the endo-nitrito (κ1–ONO) coordination in complexes 3 and 4. It has been shown that the replacement of the bromo ligand in complexes 1 and 2, either by AgOTf/NaNO2 in a... 

    Exploiting the Intrinsic Redundancy of Multicore Platforms to Achieve Low-power Fault-tolerance in Embedded Applications

    , M.Sc. Thesis Sharif University of Technology Safari, Sepideh (Author) ; Ejlali, Alireza (Supervisor)
    Abstract
    VLSI technology scaling has resulted in the integration of a larger number of cores in a single chip in successive technology nodes, offering a great potential to realize task-level redundancy for reliability enhancement in safety-critical applications. However, since battery technology no longer advances commensurately with integration density, multi-core platforms may have limited utility in battery-powered embedded systems. In this thesis, we propose an energy-budget-aware reliability management (enBudRM) method for multi-core embedded systems featuring hybrid energy source (with renewable and non-renewable energy sources). Our method is composed of two phases. In the offline phase, we... 

    Controller Design to Reduce Effects of Radome Error Slope on the Stability of Misssile

    , M.Sc. Thesis Sharif University of Technology Safari, Ahmad (Author) ; Fathi, Mohsen (Supervisor)
    Abstract
    In this project three models addressed before in the references are reviewed and the stability margins of radome error slope obtained by analytical method. Then a new model who is usefull in practical applications presented. Because of complication of this model the model is simplified and stability margins for radome error slope derived in simplified model. It is also shown that simplified applicative model is similar to model purposed in ref. [6]. Then a PD controller designed to stabilize some of models reviewed in chapter 3. The equations derived before verified in continuation of the project. The effects of parameters on the stability of missile analysed by equations derived in chapter... 

    Reliability Improvement of Three-Dimensional Network-on-Chips by Thermal Management

    , M.Sc. Thesis Sharif University of Technology Safari, Maedeh (Author) ; Miremadi, Ghasem (Supervisor)
    Abstract
    Three-dimensional network-on-chip (3D NoC), the combination of NoC and die-stacking 3D IC technology, is motivated to achieve lower latency, lower power consumption, and higher network bandwidth. 3D NoCs reduce length of communication link and transmition delay by die stacking. However, the length of heat conduction path and power density per unit area increase as more dies are stacked vertically. High temperature results in longer propagation delay and increases the leakage power. If heat production in the chip is not managed, low cooling rate for these layers is a threat for the chip performance and reliability. To solve the thermal problems, thermal management schemes were proposed in the... 

    Grapheme to Phoneme Conversion using Deep Neural Networks

    , M.Sc. Thesis Sharif University of Technology Safari, Arash (Author) ; Sameti, Hossein (Supervisor)
    Abstract
    The goal of this research is to convert letter to phoneme using deep neural networks. As the deep neural networks are among the best methods for speech and text processing (The highest accuracy in converting text to letter in English language is obtained by using deep neural networks too.), multilayer deep neural networks are used in this research to increase the accuracy. It should be noted that deep neural networks have not been used for converting text to phoneme in Persian language before. In this research a rule based alignment method based on our preposed rule is presented and achieved an accuracy more than 98%. Several approaches for converting word to grapheme with emphasis on the... 

    Formation of Plasma Electrolytic Oxidation Coating on Aa5052 And Az31 Alloys Joint with Friction Stir Welding

    , M.Sc. Thesis Sharif University of Technology Safari, Saeed (Author) ; Ghorbani, Mohammad (Supervisor)
    Abstract
    Plasma Electrolytic oxidation has recently been known as a new technology in surface engineering. It is one of the low-cost techniques used for improving corrosion and wear resistance in Al-Mg alloys. The purpose of this study first is to attach aluminum and magnesium alloys safely and without any defects, and then finding the optimum coating condition in connection line to achieve most possible corrosion resistance. For this purpose, first of all optimization of Al-Mg alloys friction stir welding (FSW) condition is required. After required investigations, it was shown that the weld created between Aluminum and Magnesium sheets by the cylindrical pin moving in a rotational speed of 550... 

    Joint Energy and Reliability Management in Mixed-Criticality System

    , Ph.D. Dissertation Sharif University of Technology Safari, Sepideh (Author) ; Hessabi, Shaahin (Supervisor)
    Abstract
    The advancement of Cyber-physical Systems (CPSs) has attracted attention to Mixed-Criticality Systems (MCSs), both in research and industrial designs. Mixed-criticality systems (MCSs) integrate different types of functionalities with varying levels of criticality onto the shared computing platform. The scheduling algorithms for MCSs must guarantee that all high criticality tasks are completed by their deadlines in different operation modes of the system. In addition to certification, as multi-core platforms are becoming a dominant trend in designing MCSs, simultaneous energy and reliability management, and Quality of Service (QoS) are other significant challenges in designing MCSs. Indeed,... 

    The investigation of Odor Producing Factors in Kish Island Refineries and Sewage Collection System

    , M.Sc. Thesis Sharif University of Technology Jamali, Hamid Reza (Author) ; Hashemian, Jamal (Supervisor)
    Abstract
    From the main factors causing an unpleasant odor can refer to indoles, askatels, mercaptans, some volatile organic compounds, sulfide hydrogen, ammonia, and the number of odor-causing compounds, which are also found in the wastewater facilities and sometimes produce unpleasant odors. Meanwhile, ammonia (Pungent and irritating odor) and sulfide hydrogen (colorless poisonous gas with the odor of rotten eggs) can be presented as major factors in sewage odor.
    Several factors are involved in the foul-smelling hydrogen sulfide gas collection system and wastewater treatment. A few of them include numerous sewage pumping stations, selected the appropriate gradient in the collection system,... 

    Synthesis and Investigation of Tribological Properties of Rubber-Based Friction Materials with low Friction Coefficient

    , M.Sc. Thesis Sharif University of Technology Jamal Anaraki, Maryam (Author) ; Shojaei, Akbar (Supervisor)
    Abstract
    Nowadays, replacement of traditional cast iron shoes with composite brake blocks is a main project in railway systems. The main purpose of this replacement is noise reduction( for example by about 10dB for a 100km/h freight train). One of the main sources of noise emission is the rolling sound of the wheel on the rail. The rougher and more out-of-round wheel surface, the greater the noise produced. Cast iron brake shoes, still widely used on freight wagons, make the wheel surface much rougher than composite brake blocks due to the fusing of minute metal particles into the tread surface during braking. It is therefore necessary to replace the current cast iron brake shoe with a synthetic...