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mohammadi-manesh--mehdi
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Design of an Absorption Chiller for Light Vehicles
, M.Sc. Thesis Sharif University of Technology ; Behshad Shafiee, Mohammad (Supervisor)
Abstract
Reducing fossil fuels and increasing urban air pollution, has made the automotive industry to reduce the fuel consumption of their engines by various approaches. Removing the compressor of air conditioning system by replacing the absorption chiller instead of inverse rankin cycle is a shortcut to reduce the fuel consumption which at the same time reduces costs of using air conditioning system for occupants. Design of a 3 kW lithium bromide-water absorbent chiller has verified based on environmental conditions and car space limitations and using the combustion products as the heat source of system. K4M engine of L90 sedan Car as an internal combustion engine sample’s exhaust manifold has been...
An Approach to Optimize Resource Allocation and Strategies to Control Infectious Diseases
, M.Sc. Thesis Sharif University of Technology ; Najafi, Mehdi (Supervisor)
Abstract
Infectious diseases have always been a threat to mankind, and is the greatest causes of death of children and young people. Although this type of diseases is a serious threat to public health; the allocated resources in responding to a semi-large pandemic is inadequate. Therefore, it is important to spend the resources in the most effective and efficient ways to improve pandemic response capability. That is why considerable research be devoted to study different aspects of epidemics, and developed mathematical approaches to choose appropriate strategies in pandemic response. Since the epidemic models are simplified means to describe the transmission of disease, researchers often use these...
Gauge Theory and Topological Order: Superconducting Chains
, Ph.D. Dissertation Sharif University of Technology ; Kargarian, Mehdi (Supervisor)
Abstract
Notwithstanding massive efforts put forward in the last few decades, the experimental realization of quantum states with topological orders in a controlled way and accessible conditions has remained elusive. The realization of such states in fractional quantum Hall states requires extreme conditions like the cryogenic temperatures and strong magnetic fields. Also, the existence of a pure topological order in spin liquid materials is limited by disorder, subleading interactions, or lack of enough experimental information. Alternatively, we may think of extrinsic models to simulate the exotic phases by combining a set of naturally accessible quantum systems. Our approach involves the...
Numerical Calculation of Bearing Capacity of Foundations Near or on the Slopes
, M.Sc. Thesis Sharif University of Technology ; Ahmadi, Mohammad Mehdi (Supervisor)
Abstract
Bearing capacity of foundations is one of the most controversial issues in foundation engineering. In this study regarding to the previous researches which has done by the other researchers the bearing capacity factors of a footing has calculatedusing finite element method. On the next step of this study some footings has modeled on different positions near slopes with different angles and bearing capacity of them has calculated, then some strip foundation has modeled and bearing capacity of them has calculated and compared with the values of the footings in this study and strip foundations of the other researches. Furthermore some foundations have modeled on the solpe and bearing capacity...
In vitro dissolution of plasma-sprayed hydroxyapatite coatings with different characteristics: Experimental study and modeling
, Article Biomedical Materials ; Volume 3, Issue 1 , 2008 ; 17486041 (ISSN) ; Ziaei Moayyed, A. A ; Sheikh Mehdi Mesgar, A ; Sharif University of Technology
2008
Abstract
The dissolution of plasma-sprayed hydroxyapatite (PHA) coatings with different characteristics, produced by various spraying conditions, in a Tris-buffered solution at pH 7.4 was experimentally studied through the measurement of the release of calcium ions. The phase composition of the coatings at surface and interface, and the porosity were evaluated. The analytical modeling revealed that the calcium dissolution process was composed of two stages. The first stage was found to be both surface and diffusion controlled. The second stage was an exactly diffusion-controlled dissolution. In the first stage, the rate of dissolution and the solubility of the coatings with minimum contents of...
Paclitaxel molecularly imprinted polymer-PEG-folate nanoparticles for targeting anticancer delivery: Characterization and cellular cytotoxicity
, Article Materials Science and Engineering C ; Volume 62 , 2016 , Pages 626-633 ; 09284931 (ISSN) ; Darvishi, B ; Azizi Ishkuh, F ; Shahmoradi, E ; Mohammadi, A ; Javanbakht, M ; Dinarvand, R ; Atyabi, F ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
The aim of this work was to synthesize molecularly imprinted polymer-poly ethylene glycol-folic acid (MIP-PEG-FA) nanoparticles for use as a controlled release carrier for targeting delivery of paclitaxel (PTX) to cancer cells. MIP nanoparticles were synthesized by a mini-emulsion polymerization technique and then PEG-FA was conjugated to the surface of nanoparticles. Nanoparticles showed high drug loading and encapsulation efficiency, 15.6 ± 0.8 and 100%, respectively. The imprinting efficiency of MIPs was evaluated by binding experiments in human serum. Good selective binding and recognition were found in MIP nanoparticles. In vitro drug release studies showed that MIP-PEG-FA have a...
Theoretical and Numerical Analysis of Shock Waves Propagation in Porous Medium
, Ph.D. Dissertation Sharif University of Technology ; Ahmadi, Mohammad Mehdi (Supervisor) ; Mohammadi, Soheil ($item.subfieldsMap.e)
Abstract
Particulate porous mateials have always been of interest in terms of reducing shock waves effects in different protective applications. Therefore, the physics governing the flow in porous media is especially significant for which different models have been presented by the researchers. The complexities of these media have caused many existing models to be unable to properly predict the behavior of granular media under shock loadings. On the other hand, the complexity of the equations makes the numerical solution of them cumbersome and costly in a way that many researchers do not solve the whole coupled equations and reduce their number. In addition, current high-resolution TVD solutions of...
Immobilized manganese porphyrin on functionalized magnetic nanoparticles via axial ligation: Efficient and recyclable nanocatalyst for oxidation reactions
, Article Journal of Coordination Chemistry ; Volume 68, Issue 13 , 2015 , Pages 2347-2360 ; 00958972 (ISSN) ; Mortazavi Manesh, A ; Sharif University of Technology
Taylor and Francis Ltd
2015
Abstract
Magnetic nanoparticles (MNPs), Fe3 O4 @SiO2 , have been prepared and functionalized by 3-(chloropropyl)trimethoxysilane and then by imidazole to synthesize Fe3 O4 @SiO2 -Im. The functionalized Fe3 O4 nanoparticles were used as a support to anchor manganese porphyrin via axial ligation. The prepared catalyst was characterized by elemental analysis, FT-IR spectroscopy, X-ray powder diffraction, UV-vis spectroscopy, and scanning electron microscopy. Application of immobilized manganese porphyrin as a heterogeneous catalyst in oxidation of alkenes and sulfides was explored. To find suitable reaction conditions,...
Nanoparticle supported, magnetically separable manganese porphyrin as an efficient retrievable nanocatalyst in hydrocarbon oxidation reactions
, Article RSC Advances ; Volume 6, Issue 47 , 2016 , Pages 41551-41560 ; 20462069 (ISSN) ; Mortazavi Manesh, A ; Sharif University of Technology
Royal Society of Chemistry
2016
Abstract
A manganese porphyrin, meso-tetrakis(pentafluorophenyl)porphyrinato manganese(iii) acetate, Mn(TPFPP)OAc, was immobilized on silica-coated magnetic Fe3O4 nanoparticles functionalized with 3-aminopropyltriethoxysilane (APTS) through the amino propyl linkage using a grafting process in toluene solvent. This enabled the covalent immobilization of Mn(iii) porphyrin via an aromatic nucleophilic substitution reaction, to afford the Fe3O4@SiO2-NH2@MnPor catalyst. The resulting nanoparticles were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), FT-IR spectroscopy, UV-Vis spectroscopy, elemental analysis (CHN), atomic absorption spectroscopy (AAS), and vibrating...
Synthesis and characterization of molybdenum (VI) complex immobilized on polymeric Schiff base-coated magnetic nanoparticles as an efficient and retrievable nanocatalyst in olefin epoxidation reactions
, Article Applied Organometallic Chemistry ; Volume 34, Issue 3 , 2020 ; Bagherzadeh, M ; Sharif University of Technology
John Wiley and Sons Ltd
2020
Abstract
In this study, a new polymeric functionalized magnetic nanocatalyst containing a molybdenum Schiff base complex was prepared using a few consecutive steps. Poly (methylacrylate)-coated magnetic nanoparticles were synthesized via radical polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the amidation of the methyl ester groups with hydrazine. Polymeric functionalization efficiently provides the advantage that more catalytic units can be grafted on the surface of magnetic nanoparticles. The functionalization process was continued with salicylaldehyde which introduced Schiff base groups on to the surface of the polymeric support. In the final step, the desired...
Impact of Practical Beam Shapes on the Performance of Free Space Optical
, M.Sc. Thesis Sharif University of Technology ; Marvasti, Farokh (Supervisor)
Abstract
Free-Space Optical (FSO) communication has received an increasing attention in recent years with its ability to achieve ultra-high data rates (at the order of multiple gigabits per second) over unlicensed optical spectrum. A major degrading factor, particulary in long links is the stmospheric turbulence induced fading. In this thesis, we use spatial diversity and use and make several contributions to the performance analysis of MIMO (Mutli Input-Multi Output) FSO systems. We use MRC(Maximum Ratio Combining),EGC(Equal Gain Combinig),SC(Selection Combinig) and yield significant performance improvments. Finally we import the charectristic of different beamshapes and yields performance...
Expounding the Meaning of Time in Evolutionary Process
, M.Sc. Thesis Sharif University of Technology ; Shafiee, Afshin (Supervisor)
Abstract
The question of the time is one of the obscure and challenging subjects which has been discussed as a mysterious problem in various civilizations. In ancient Greece, the question has been debated among the supporters of existence and eternity. We observe the words of Plato, on the existence of the absolute essence of eternity against the change and transition time instantiated as a conducted river in the Heraclitus view. Other discussions focused on the relationship between the change and displacement, or the the spatial relations to which Aristotle paid attention. With the passing of time from the ancient and medieval eras to the Renaissance period, along with the growth of the science in...
Immobilized Manganese-porphyrin and Molybdenum-Schiff Base Complexes on Functionalized Magnetic Nanoparticles as Efficient Recyclable Nanocatalysts in Hydrocarbon and Sulfide Oxidation Reactions
, Ph.D. Dissertation Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this thesis, functionalized Fe3O4 nanoparticles have been utilized as a support for immobilization of homogeneous catalysts. The catalytic activity of the supported heterogeneous nanocatalysts was investigated in hydrocarbon and sulfide oxidation reactions. In the first part of this research, imidazole functionalized Fe3O4 nanoparticles (Fe3O4@SiO2-Im) were used as a support to anchor manganese porphyrin complex, [MnT(4-OMeP)P]OAc; via axial ligation. Catalytic application of the immobilized manganese porphyrin was studied in oxidation of alkenes and sulfides. To find suitable reaction conditions, the effect of different parameters such as solvent and temperature on immobilization process...
The effect of annealing treatment on mechanical properties of aluminum clad steel sheet
, Article Materials and Design ; Volume 24, Issue 8 , 2003 , Pages 617-622 ; 02641275 (ISSN) ; Karimi Taheri, A ; Sharif University of Technology
Elsevier Ltd
2003
Abstract
In this paper, the effects of annealing temperature and time on mechanical properties and bond strength of aluminum clad steel sheet are evaluated. The results indicate that there exist an optimum annealing temperature and time for achieving a suitable formability and bonding strength between the clad layer and base metal. At this annealing time and temperature, the brittle intermetallic layer at the intimate interface of the layers is minimized. © 2003 Elsevier Ltd. All rights reserved
An investigation of deformation behavior and bonding strength of bimetal strip during rolling
, Article Mechanics of Materials ; Volume 37, Issue 5 , 2005 , Pages 531-542 ; 01676636 (ISSN) ; Taheri, A. K ; Sharif University of Technology
2005
Abstract
A mathematical model for cold rolling of two-layer strip is proposed using the upper bound theorem to investigate the plastic deformation behavior of the strip at the roll gap. The effects of total thickness reduction on the rolling power, rolling force, thickness reductions of each layer, and bonding strength of bimetal strip are discussed. Furthermore, experiments on two-layer strip rolling are conducted by employing aluminum-tin alloy and mild steel as the layers of the two-layer strips. It is found that all of theoretical predictions are in good agreement with the experimental measurements. Through the study, it becomes clear that the proposed analytical model is applicable for...
Theoretical and experimental investigation of cold rolling of tri-layer strip
, Article Journal of Materials Processing Technology ; Volume 166, Issue 2 , 2005 , Pages 163-172 ; 09240136 (ISSN) ; Taheri, A. K ; Sharif University of Technology
2005
Abstract
A mathematical model for cold rolling of symmetrical sandwich strip is proposed using the upper bound theorem to investigate the plastic deformation behavior of the strip at the roll gap. The velocity fields derived from the proposed upper bound model can satisfy automatically the volume constancy and the velocity boundary conditions within the roll gap. Effects of various rolling conditions such as the initial thickness and flow stress of each layer in the strip, total thickness reduction and the frictional condition between the strip and roll on the rolling power, rolling force, and thickness reduction of each layer are discussed. Furthermore, experiments on sandwich strip rolling are...
Bond strength and formability of an aluminum-clad steel sheet
, Article Journal of Alloys and Compounds ; Volume 361, Issue 1-2 , 2003 , Pages 138-143 ; 09258388 (ISSN) ; Karimi Taheri, A ; Sharif University of Technology
2003
Abstract
The production of an aluminum-clad steel sheet by the cold rolling process is a more efficient and economical approach compared with the other types of processes utilized for the production of such sheets. In this process, high plastic deformation of two metals, aluminum and steel, is necessary to create the cold bonding between the intermediate surfaces. Therefore, the work-hardened sheet must be annealed in order to obtain a high formability. Heat treatment of the sheet is, however, difficult due to the formation of a brittle intermetallic compound of aluminum and iron at the interface between the layers during heat treatment. In this investigation, the formability of these sheets was...
Study of mechanisms of cold roll welding of aluminium alloy to steel strip
, Article Materials Science and Technology ; Volume 20, Issue 8 , 2004 , Pages 1064-1068 ; 02670836 (ISSN) ; Taheri, A. K ; Sharif University of Technology
Maney Publishing
2004
Abstract
The mechanisms of cold roll welding of aluminium alloy to steel strip has been assessed based on a study of interfacial behaviour at deformations of up to 60% together with the surface characteristics of peeled Al clad steel strip. The proposed mechanisms are applicable where the contact surfaces are degreased and then scratch brushed before the rolling deformation. According to this mechanisms the scratch-brushed layers are fractured shortly after entering the roll gap at a reduction of approximately 10%, which is about the threshold deformation for the roll bonding of aluminium to steel. The transfer cracks formed then become wider so that the distance between each coherent block increases...
Swing up and arm trajectory tracking of the furuta pendulum with sliding mode control
, Article 5th RSI International Conference on Robotics and Mechatronics, IcRoM 2017, 25 October 2017 through 27 October 2017 ; 2018 , Pages 346-351 ; 9781538657034 (ISBN) ; Nikzad Goltapeh, A ; Sharif University of Technology
2018
Abstract
In this paper, the swing-up problem of the Furuta pendulum has been solved by introducing a new combined method based on the frequency response, and the sliding mode method. Furthermore, a trajectory tracking controller has been introduced and applied to the Furuta pendulum; which the pendulum remained regulated at the upward position, while the arm tracks a desired time-varying trajectory. The hierarchical sliding mode control (HSMC) approach has been employed to achieve the mentioned goals. The Furuta system is made up of two subsystems. Based on this physical structure, the hierarchical structure of the sliding surfaces is designed as follows: first, the sliding surface of each subsystem...
Synthesis, characterization and catalytic activity of supported vanadium Schiff base complex as a magnetically recoverable nanocatalyst in epoxidation of alkenes and oxidation of sulfides
, Article Journal of Organometallic Chemistry ; Volume 897 , 2019 , Pages 200-206 ; 0022328X (ISSN) ; Bahjati, M ; Mortazavi Manesh, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
A new magnetically separable nanocatalyst was successfully synthesized by immobilizing of vanadyl acetylacetonate complex, [VO(acac)2], onto silica coated magnetite nanoparticles previously functionalized with 3-aminopropyltriethoxysilane (3-APTES) and reacted by 5-bromosalicylaldehyde to form Schiff base moiety. The obtained nanocatalyst was characterized by elemental analysis (CHN), FT-IR spectroscopy, Powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), inductively coupled plasma optical emission spectrometry (ICP-OES) and thermogravimetric analysis (TGA). Eventually, the resulting nanoparticles were used as catalyst for epoxidation of alkenes and...