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    کلیدواژه های تکراریCurcumin loading potentiates the neuroprotective efficacy of Fe3O4 magnetic nanoparticles in cerebellum cells of schizophrenic rats

    , Article Biomedicine and Pharmacotherapy ; Volume 108 , 2018 , Pages 1244-1252 ; 07533322 (ISSN) Naserzadeh, P ; Ashrafi Hafez, A ; Abdorahim, M ; Abdollahifar, M. A ; Shabani, R ; Peirovi, H ; Simchi, A ; Ashtari, K ; Sharif University of Technology
    2018
    Abstract
    Background: The aim of this study was to investigate the neurotoxic effects of Fe3O4 magnetic- CurNPs on isolated schizophrenia mitochondria of rats as an in vivo model. Methods: We designed CMN loaded superparamagnetic iron oxide nanoparticles (SPIONs) (Fe3O4 magnetic- CurNPs) to achieve an enhanced therapeutic effect. The physicochemical properties of Fe3O4 magnetic- CurNPs were characterized using X-ray diffraction (XRD), and dynamic laser light scattering (DLS) and zeta potential. Further, to prove Fe3O4 magnetic- CurNPs results in superior therapeutic effects, and also, the mitochondrial membrane potential collapse, mitochondrial complex II activity, reactive oxygen species generation,... 

    Three Dimentional Printing of Highly Porous Metamaterials Based on Polyurethane/Tricalcium Phosphate Composite for Tissue Engineering

    , M.Sc. Thesis Sharif University of Technology Hosseini, Danial (Author) ; Simchi, AbdolReza (Supervisor) ; Tavakoli, Rouhollah (Supervisor)
    Abstract
    In the last decade, mechanical metamaterials have attracted more attention due to new design principles that combine the concept of hierarchical architecture with material size effects at the micro or nano scale. This strategy shows extraordinary mechanical performance that we use in unknown parts of the material property space, including strength-to-density ratios, extraordinary flexibility, and the ability to absorb energy with brittle components. The aim of this research was to print metamaterial scaffolds from a combination of biocompatible and bioactive to be used as scaffolds in bone tissue engineering. In addition to the biological properties appropriate to the host tissue, the... 

    3D Bioprinting of Amniotic Membrane-Based Nanocomposite for Tissue Engineering Applications: Evaluation of Rheological, Mechanical and Biological Properties

    , Ph.D. Dissertation Sharif University of Technology Kafili, Golara (Author) ; Simchi, Abdolreza (Supervisor) ; Tamjid, Elnaz (Supervisor) ; Niknejad, Hassan (Co-Supervisor)
    Abstract
    3D bioprinting is an additive manufacturing method that facilitates the deposition of the desired cells and biomaterials at any pre-defined location. This technique also enables control over the internal structure and external dimensions of printed constructs. Among various biomaterials used as bioinks, the bioinks derived from decellularized extracellular matrixes (dECMs) have attracted significant attention due to their bioactivity and being a rich source of biochemical cues. Here in this study, the decellularized amnion membrane (dAM) has been selected as the main component of the bioink formulation because of its biocompatibility, low immunogenicity, antibacterial property, abundance,... 

    Electrophoretic Deposition of Alginate-Bioglass-Nanodiamond Nanocomposites and Evolution of their Bioactivity

    , M.Sc. Thesis Sharif University of Technology Mansoorianfar, Mojtaba (Author) ; Simchi, Abdollreza (Supervisor)
    Abstract
    Recently, diamond nanoparticles have attracted interest for biomedical applications such as drug delivery, targeted cancer therapies, fabrication of tissue scaffolds and biosensors. In the present work, elecrophoretic deposition (EPD) of nanodiamond-bioactive glass-alginate nanocomposite was studied. In vitro bioactivity and biocompatibility of the nanocomposite were evaluated in simulated body fluid (SBF) and by MTT assay. The EPD process was performed under different conditions in order to obtain a uniform coating on the surface of 316L stainless steel substrate. The stability of the suspension was determined via optical sedimentation method and zeta potential analysis. It was found that... 

    Surface Passivation of PbS Colloidal Quantum Dots for Photovoltaic Applications

    , Ph.D. Dissertation Sharif University of Technology Tavakkoli, Mohammad Mahdi (Author) ; Simchi, Abdolreza (Supervisor) ; Ashuri, Hossein (Supervisor)
    Abstract
    Solution-processed quantum dots (QDs) have attracted significant attention for the low-cost fabrication of optoelectronic devices. Here, we synthesized PbS QDs via hot injection method and passivated the trap states by using short thiols and dopant elements for photovoltaic application. In order to study the effect of dopants on photovoltaic application, PbS QDs were doped by using three different cations: Cadmium, Calcium, and Zinc. The results showed that Cd dopant has a better improvement than Ca and Zn dopants in order to increase the efficiency of the PbS QDs solar cells. We achieved solar power conversion efficiencies of 5.81% using Cd therapy. Recently, hybrid nanocomposites... 

    Manipulation of Electronic Structure in Boron Nitride Nanosheets to Improve Catalytic and Photocatalytic Properties

    , M.Sc. Thesis Sharif University of Technology Hemmati, Amir (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    The variety of 2D materials and their wide range of properties, as well as numerous methods to manipulate them, have made this class of materials among prominent candidates for the future of the energy industry. Among the means available to tailor nanomaterials performance for such applications, introducing dopants and the creation of heteroatom-doped structures are of great interest. In this study, mixtures of urea, boric acid, and graphene oxide, as cheap and available precursors, were used to synthesize C-doped h-BN nanosheets. After the implementation of TGA/DSC to select a suitable calcination temperature of 950 C°, the samples were successfully synthesized with relatively precise... 

    Comparison of the Different Classical Structural Optimization Methods and Algorithms

    , M.Sc. Thesis Sharif University of Technology Moghani, Mazdak (Author) ; Joghataei, Abdolreza (Supervisor)
    Abstract
    In this thesis, the classical methods of structural optimization were studied and compared. After a comprehensive study on different methods of structural optimization, a reduced number of methods were selected in order to be used in this research. Exterior penalty function method, linear and quadratic extended penalty function methods were the selected constrained optimization methods. For unconstrained optimization, univariate method, Powell method, steepest descent method, Fletcher-Reeves method, and quasi-Newton methods of DFP and BFGS were used. And from different one-dimensional search methods studied, we used the golden section method. The structures which were optimally designed by... 

    Study of Melting and Rapid Solidification of TiAl alloy and Formation of its Diffusion Bonded Structure using Molecular Dynamics Simulation

    , M.Sc. Thesis Sharif University of Technology Yazdan Yar, Azade (Author) ; Aashuri, Hossin (Supervisor) ; Simchi, Abdolreza (Co-Advisor)
    Abstract
    The rapid pace of development of nanoscience and nanotechnology and their applications in various fields have made the study of materials in smaller scales more important than any time ever. Having an insight of materials’ microstructure and the mechanism of different phenomena in the atomic scale will be very beneficent in designing new and advanced materials or modifying the current manufacturing processes. Since molecular dynamics (MD) method has been well known as a mean of studying materials in atomic scale, it has been used in this study to investigate two different phenomena. The selection of the appropriate interatomic potential is of great importance in MD; Embedded Atom Method... 

    Investigation of Electro-Optical Properties of Heterostructures based on 2-D Layered Materials by Quantum Simulation

    , M.Sc. Thesis Sharif University of Technology Saadat Somaeh Sofla, Zahra (Author) ; Simchi, Abdolreza (Supervisor) ; Shayeganfar, Farzaneh (Supervisor)
    Abstract
    Density Functional Theory is one of the most robust Ab-intio methods for describing the structural and electronic properties of a wide range of materials. The ability to predict the material properties changes due to targeted material manipulation at the atomic scale has reduced the cost of many empirical experiments. It has improved the knowledge and understanding of the investigation and producing new materials and devices. Tow dimensional heterostructures are highly regarded due to their unique optoelectronic properties, potential application in nanoelectronic devices, energy storage devices, solid-state devices, and photovoltaic devices. In this study, the two-dimensional materials... 

    Investigation of Mechanical Milling Effects on Al-Cu and Al-CuO Powder Mixture Morphological and Structural Characteristic and Mechanical Properties Changes Resultant from Age Hardening

    , M.Sc. Thesis Sharif University of Technology Haghighatzadeh, Mehdi (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    In the present work, nanocrystalline Al-4wt%Cu alloy reinforced with nanometric Al2O3 particles was synthesized by in-situ reactive milling of Al and CuO powder mixture and hot extrusion. The effect of nanometric Al2O3 particles on the aging behavior and mechanical properties of this alloy was investigated. During mechanical milling, copper oxide were reduced and dissolved in the aluminum lattice. consequently, Al(Cu) solid solution matrix was produced. Also, nanometric Al2O3 particles were also distributed in the matrix uniformly. The powder blend was then pressed in an Al can at 100 MPa pressure and subsequently extruded at 450 0C at the extrusion ratio of 16:1. The density of the... 

    Atomistic Study of Iinterface Properties and Structure of Nickel-Silicon and Polyethelene-Ghraphene by Molecular Dynamics Simulation

    , M.Sc. Thesis Sharif University of Technology Amini, Hamed (Author) ; Kokabi, Amir Hossein (Supervisor) ; Simchi, Abdolreza (Supervisor)
    Abstract
    First atomistic simulation was used to study the deformation and fracture mechanisms of Ni-Si interfaces under tensile and shear loads dependent on the crystal structure of interface zone. Modified embedded atom method (MEAM) potential was utilized for molecular dynamics (MD) modeling. The simulation includes analysis of common neighbors, coordination number, least-square atomic local strain, and radial distribution function. The profound effect of interface crystallography on the tensile and shear deformation is shown. The highest tensile strength is obtained for interfaces with high plane density due to lowest atomic disorder while under shear loading planes with low density exhibit a high... 

    Study of Direct Joining of Nanostructured-Zirconia to 430L Stainless Steel Produced by Co-sintering Process

    , Ph.D. Dissertation Sharif University of Technology Dourandish Yazdi, Mahdi (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    In this study, the joint of co-sintered zirconia/stainless steel is investigated. To this end ZrO2-3mol%Y2O3 (TZP) and 430L stainless steel powders were utilized. The joining parameters of co-sintering in zirconia/metal were studied. In order to study the microstructure, diffusion and probable reactions at the joint boundary, HRSEM, HRTEM, EPMA and micro-focused XRD methods were employed. Shear strength of the joint was also measured. Finite element simulation of residual stresses and thermodynamic studies are utilized in the next step to analyze the experimental results. It is found that the direct joining of zirconia to 430L stainless steel is feasible by co-sintering at 1350 °C under low... 

    Numerical Modelling and Experimental Validation of Nano Colloid Droplet Formation in the Electrohydrodynamic 3D Printer

    , Ph.D. Dissertation Sharif University of Technology Mohammadi, Kaivan (Author) ; Movahhedy, Mohammad Reza (Supervisor) ; Khodaygan, Saeed (Supervisor) ; Simchi, Abdolreza (Co-Supervisor) ; Mofrad, Mohammad Reza (Co-Supervisor)
    Abstract
    The electrohydrodynamic (EHD) 3D printing technology is an Additive Manufacturing (AM) method that can be used in the manufacture of submicron-size structures. Due to the multiphysics dynamics and the multiphase nature of the microdroplet formation in the EHD printers, modeling of this phenomenon is complicated. In this thesis, the formation of a droplet in an EHD printer—under a pulsed electrical field—is simulated using a new numerical model which couples the fluid flow, the electric field distribution and the movement of the electric charges under dynamic and transient conditions. The level-set method is applied to the entire multiphysics domain in order to study the formation of the... 

    Electrophoretic Deposition of Functionally Graded NiO/YSZ for SOFC Anode Fabrication

    , M.Sc. Thesis Sharif University of Technology Zarabian, Mina (Author) ; Faghihi Sani, Mohammad Ali (Supervisor) ; Simchi, Abdolreza (Supervisor)
    Abstract
    The future crisis and environmental pollution led to increasing interest in alternative energy conversion systems such as solid oxide fuel cell (SOFC). One of the main obstacles in using SOFCs is their relatively high fabrication cost compared with their low amount of produced energy .Therefore, in the present study, fabrication of a more cost-efficient functionally graded NiO-YSZ composite for SOFC anode by electrophoretic deposition (EPD) method was investigated. In this research, the effect of different chemical parameters such as media, additives, particle size distribution and nano NiO addition were initially investigated on the stability of NiO-YSZ suspension by Zetasizer and turbidity... 

    Electrophoretic Deposition of (Mn,Co)3O4 Spinel Coating for Solid Oxide Fuel Cell Interconnects

    , M.Sc. Thesis Sharif University of Technology Mirzaei, Mohamad Mahdi (Author) ; Faghihi Sani, Mohammad Ali (Supervisor) ; Simchi, Abdol Reza (Supervisor)
    Abstract
    Solid oxide fuel cell (SOFC) is one of the promising candidates for clean energy production. Due to the high operating temperature of SOFC, a protective coating is commonly applied on the surface of interconnects to prevent oxidation. In this study, electrophoretic deposition was employed to prepare a manganese-cobalt spinel coating on the surface of ferritic stainless steel (AISISAE430) substrates. MnCo2O4 powder with an average particle size of 60 nm was utilized and the sintering behavior of the coatings at different temperatures was studied. Non-isothermal and isothermal sintering behavior of the powder compacts were examined by employing a sensitive dilatometer. Master sintering curve... 

    Synthesize and Characterization of 2D WS2 Nano-layers for Next Generation Optoelectronic Devices

    , M.Sc. Thesis Sharif University of Technology Rahmani Taji Boyuk, Mohammad Reza (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    Transition Metal Dichalcogenids (TMD) are types of 2D materials that exibit wide range of electronic, optical, mechanical, chemical, and thermal properties. These materials with MX2 general formula, have atract attentions with respect to their unusual properties because of their very limited dimensions. Their tunable properties and materials availibility make them attractive for wide range of applications. In recent years, chemical vapor deposition (CVD) methods are promising in preparing high quality TMD with scalable size, controllable thickness, and very excellent electronic properties. Also, chalenges are remaining in synthesis and transfering of TMD are difficulty for most of... 

    Synthesis and Stability Improvement of Perovskite QDs for Optoelectronic Devices

    , M.Sc. Thesis Sharif University of Technology Hasanzadeh Azar, Mahdi (Author) ; Simchi, Abdol Reza (Supervisor)
    Abstract
    In the last years, perovskite QDs have emerged as the novel candidate due to their unique optical properties such as high-absorption coefficient, long-range charge transport, low exciton-binding energy, and etc. Nonetheless, poor stability of perovskite in ambient conditions made researchers to consider this issue. Recently, amoung various types of organic-inorganic perovskites, Formamidinium lead iodide has attracted tremendous attention due to its near IR absorption wavelength in addition to the higher stability compared to MAPbI3. In this work, FAPbI3 perovskite stability improvement was investigated by several methods under different conditions. In the first step, FAPbI3 QDs colloidal... 

    Chemical Vapor Processing of 2D MoS2 Nanolayers for Next Generation Inoptoelectronic Devices: Characterization and Properties

    , M.Sc. Thesis Sharif University of Technology Sovizi, Saeed (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    Quite a few methods have been reported to synthesize monolayer MoS2, which has recently attracted scientist attentions. Fully controlled conditions, however, have not been achieved in these methods. In this research, two-dimensional MoS2 nanofilms have been synthesized by Chemical Vaper Deposition (CVD). Layer thickness of synthesized layer and effects of various parameters of used method have been investigated. Although every scientist synthesizes 2D MoS2 at 650°C in the CVD method by using seeds, in this research, it has been proved that MoS2 nanofilms can be produced at 575°C without using any seeds, which leads to lower consumption of time and price and increases the quality of... 

    Shear Capacity of Ultra-High Performance Concrete Rectangular Beams

    , Ph.D. Dissertation Sharif University of Technology Pourbaba, Masoud (Author) ; Joghataie, Abdolreza (Supervisor)
    Abstract
    The application of ultra-high performance concrete (UHPC) as an alternative to conventional/ normal concrete (NC) has grown rapidly in recent years. However, there is limited knowledge on its shear behavior, which is essential for developing design guidelines for structural applications. A detailed parametric study was conducted on 38 beam specimens, half of which were made of UHPC and the other half made of NC. To ensure applicability of findings, two types of UHPC mixes were used, a proprietary and a generic mix. Eighteen of the beams were prepared and tested in Tabriz, Iran, while the other 20 were made and tested in Miami, FL. Test parameters included type of concrete (UHPC and NC),... 

    Design and Synthesis of Ni-Zn Magnetic Nanoparticles for Hyperthermia Treatment

    , Ph.D. Dissertation Sharif University of Technology Delavari, Hamid (Author) ; Madaah Hosseini, Hamid Reza (Supervisor) ; Simchi, Abdolreza (Supervisor)
    Abstract
    Hyperthermia (also called thermal therapy or thermotherapy) is defined as a type of cancer treatment in which body tissue is exposed to high temperatures, to damage and kill cancer cells, or to make cancer cells more sensitive to the effects of radiation and certain anticancer drugs. The temperature increase required by hyperthermia can be achieved via different heat sources, such as electromagnetic radiation waves (radiofrequency or microwave, ultrasound waves and electrical current. These techniques have shown good results, however, the major problem with present conventional methods is reaching homogenous heat distribution and therapeutic temperatures in the deep region of the tumor to be...