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hosseini-hosseinabad--morteza
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Copper Oxide/g-C3N4 Nanocomposites: Synthesis and Optical and Photocatalytic Properties Investigation
, M.Sc. Thesis Sharif University of Technology ; Sadrnezhaad, Khatiboleslam (Supervisor)
Abstract
Herein, cupric oxide (CuO)/graphitic carbon nitride (g-C3N4) is synthesized under microwave irradiation for enhanced photoelectrochemical (PEC) performance and photostability. A facile, one-pot method was utilized to directly deposit the nanocomposite onto FTO from a solution containing copper precursor and urea. Possible mechanisms of CuO/g-C3N4 formation and PEC performance improvement were examined via XRD, FTIR, FESEM, XPS, UV-Vis, and PL. Controlled amounts of urea determined the morphological evolution of CuO and the formation of a protective carbon layer, while its excess quantity converted to g-C3N4 in the presence of CuO. Through heat treatment of the nanocomposite, carbon-doped...
Cycling performance of LiFePO4/graphite batteries and their degradation mechanism analysis via electrochemical and microscopic techniques
, Article Ionics ; 2021 ; 09477047 (ISSN) ; Mosallanejad, B ; Mohammadzad, M ; Hosseini Hosseinabad, S. M ; Ramakrishna, S ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In this work, cycling-induced aging occurring in 18650-type LiFePO4/graphite full cells at different C-rates is studied extensively. The mechanism of performance degradation is investigated using a combination of electrochemical and microstructural analyses. Half-cell studies are carried out after dismantling the full cells, using fresh and cycled LiFePO4 cathode and graphite anode to independently study them. The results show that the capacity of LiFePO4 electrodes is significantly recovered. The rate of capacity fading in the discharge state considered as irreversible capacity in the graphite is higher than LiFePO4 half cells, indicating a greater degradation in the performance of this...
Cycling performance of LiFePO4/graphite batteries and their degradation mechanism analysis via electrochemical and microscopic techniques
, Article Ionics ; Volume 28, Issue 1 , 2022 , Pages 213-228 ; 09477047 (ISSN) ; Mosallanejad, B ; Mohammadzad, M ; Hosseini Hosseinabad, S. M ; Ramakrishna, S ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
In this work, cycling-induced aging occurring in 18650-type LiFePO4/graphite full cells at different C-rates is studied extensively. The mechanism of performance degradation is investigated using a combination of electrochemical and microstructural analyses. Half-cell studies are carried out after dismantling the full cells, using fresh and cycled LiFePO4 cathode and graphite anode to independently study them. The results show that the capacity of LiFePO4 electrodes is significantly recovered. The rate of capacity fading in the discharge state considered as irreversible capacity in the graphite is higher than LiFePO4 half cells, indicating a greater degradation in the performance of this...
Investigation of Strength and Ductility of Hinged Khorjini Connection
, M.Sc. Thesis Sharif University of Technology ; Moghaddam, Hassan (Supervisor) ; Eskandari, Morteza (Co-Advisor)
Abstract
Khorjini connection is a type of connection in steel frames, in which the beam remains continuous at the intersection with column. In its ordinary form, this beam is connected to the face of column section using upper and lower angles. This type of connection is frequently used in construction of steel frames in Iran due to economic advantages and ease of fabrication. However since it is rarely used in other countries, its behavior and method of design is not described in international references and standards. The failure of the connections is a dominant type of seismic fraction in a building (The main reason of structural failures in Manjil and Roudbar earthquake – 1990). Contrary to the...
Evaluation of activity of zinc oxide nanoparticles on human rotavirus and multi-drug resistant acinetobacter baumannii
, Article Pharmaceutical Nanotechnology ; Volume 11, Issue 5 , 2023 , Pages 475-485 ; 22117385 (ISSN) ; Khales, P ; Hosseini Hosseinabad, M ; Farahmand, M ; Poortahmasebi, V ; Habib, Z ; Tavakoli, A ; Sharif University of Technology
Bentham Science Publishers
2023
Abstract
Background: Rotaviruses are the cause of acute gastroenteritis and severe diarrheal diseases in children worldwide. Children under the age of five are more susceptible to rotavirus infections. Due to such as the lack of effective drugs and supportive therapy only, the development of new antiviral agents against rotaviruses is required. Multi-drug-resistant Acinetobacter baumannii is also one of the most challenging Gram-negative bacteria to control and treat due to its antibiotic resistance, particularly in intensive care units. Objective: This study aimed to investigate the activity of zinc oxide nanoparticles against human rota-virus and multi-drug resistant Acinetobacter baumannii....
Enhanced electrochemical performance and thermal stability of ZrO2- And rGO-ZrO2-Coated Li[Ni0.8Co0.1Mn0.1]O2Cathode material for Li-Ion batteries
, Article ACS Applied Energy Materials ; Volume 4, Issue 1 , 2021 , Pages 934-945 ; 25740962 (ISSN) ; Razmjoo Khollari, M. A ; Esmaeili, M ; Heidari, E ; Hosseini Hosseinabad, S. M ; Siavash Moakhar, R ; Dolati, A ; Ramakrishna, S ; Sharif University of Technology
American Chemical Society
2021
Abstract
LiNi0.8Co0.1Mn0.1O2 (NCM811) has been considered as a promising cathode for Li-ion batteries (LIBs) due to its high electrochemical capacity and low cost; however, poor cycling stability is one of the main restricting factors in industrial applications of the NCM811 cathode material. Notably, the capacity fading and low structural stability of NCM811 are intensified at elevated temperatures. ZrO2- and composite rGO-ZrO2-coated NCM811 were fabricated by a facile wet chemical method and evaluated at 25 and 55 °C to overcome these impediments. The ZrO2 coating provides superior cycling and thermal stability and perfectly protects the cathode active material from deleterious side reactions, and...
Electrochemical performance and elevated temperature properties of the TiO2-Coated Li[Ni0.8Co0.1Mn0.1]O2 cathode material for high-safety li-ion batteries
, Article ACS Applied Energy Materials ; Volume 4, Issue 5 , 2021 , Pages 5304-5315 ; 25740962 (ISSN) ; Azar, M. K ; Esmaeili, M ; Malekpour, N ; Hosseini Hosseinabad, S. M ; Moakhar, R. S ; Dolati, A ; Ramakrishna, S ; Sharif University of Technology
American Chemical Society
2021
Abstract
Nowadays, the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material has attracted great research interest due to its high energy density and less usage of costly raw materials. However, the high nickel content of NCM811 brings about an extremely unstable interface between the electrode and electrolyte and therefore inferior cyclic stability. Herein, we have proposed a straightforward method to deliver 1, 2, and 4 wt % of TiO2 nanoparticles (NPs) on the surface of the NCM811 cathode material and to improve its properties at room and high temperatures. Based on scanning electron microscopy and transmission electron microscopy observations, the coating thickness varies from 10 to 35 nm and the 2 wt %...
Synthesis and Characterization of Colloidal Superparamagnetic Iron Oxide and Iron/Iron Oxide Nanoparticles as MRI Contrast Agent
, Ph.D. Dissertation Sharif University of Technology ; Madaah Hosseini, Hamid Reza (Supervisor) ; Seyed Reyhani, Morteza (Supervisor)
Abstract
As contrast enhancement agent, two different structures of superparamagnetic nanoparticles were synthesized. Iron oxide nanoparticles were prepared through an alkaline coprecipitation method of Iron (II) and (III) ions. PEG-6000 was used as biocapping material and its effect on particle size, colloidal stability and cytotoxicity was evaluated. On the other hand, novel core/shell structures were produced by NaBH4 reduction process of iron (III) in an aqueous media following by further oxidation by two different methods using (CH3)3NO oxygen transferring agent and exposure to oxygen flow. In both cases, structural examinations were conducted via X-ray diffraction, electron microscopy and...
Synthesis of Novel Heterocycle Spiroindoline-2-thion, Spirodihydropyridine, Pyrrolopyrimidine and Furocoumarin Compounds and Using New Functionalized Magnetic and Mesoporous Nano Catalyst for Organic Transformations
, Ph.D. Dissertation Sharif University of Technology ; Matloubi Moghaddam, Firouz (Supervisor)
Abstract
In the first section of the present thesis, a number of novel heterocycles were prepared; they include spirodihydropyridine, spiroindoline-2-thion, and pyrrolopyrimidines. The major advantages of the current investigation encompass high yields, short reaction times, mild reaction conditions and feasibility and low-cost materials. In the second section of this thesis, heterogeneous catalysts based on magnetic nanoparticles coated with organosilanes were synthesized. These catalysts were synthesized by hydrolysis of tetraethyl organosilanes and other organosilicons such as 3-aminopropyl triethoxy silane. The synthesized scaffolds were used to stabilize precious metals as Pd and Cu. The...
One-pot microwave synthesis of hierarchical C-doped CuO dandelions/g-C3N4 nanocomposite with enhanced photostability for photoelectrochemical water splitting
, Article Applied Surface Science ; Volume 530 , 2020 ; Siavash Moakhar, R ; Soleimani, F ; Sadrnezhaad, S. K ; Masudy Panah, S ; Katal, R ; Seza, A ; Ghane, N ; Ramakrishna, S ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Cupric oxide (CuO) is a semiconductor of choice for photocathode in photoelectrochemical (PEC) applications due to its great sunlight absorption capability. However, photocorrosion is the main drawback of CuO. Herein, CuO/graphitic carbon nitride (g-C3N4) with a unique microstructure, enhanced PEC performance, and considerable photostability is synthesized under microwave irradiation. A facile, one-pot method is utilized to directly deposit the nanocomposite onto fluorine-doped tin oxide from a solution containing copper precursor and urea. Possible mechanism of CuO/g-C3N4 formation through this novel method is investigated. It is elucidated that controlled amounts of urea critically...
Design, Optimization and Numerial Simulation of ASU Multi Stream Plate Fin Heat Exchenger
, M.Sc. Thesis Sharif University of Technology ; Afshin, Hossein (Supervisor) ; Sheikhi, Aras (Supervisor)
Abstract
One of the most important process equipments in cryogenic industries that include air separation and liquifed natural gas processes, are their heat exchangers that are the plate and fin type. In this study the aim is to develop a code in MATLAB software to thermal design and numerial simulation of a multi stream plate fin heat exchanger that is in a cryogenic air separation cycle. In design mode, an ASU multi stream plate fin exchanger that its duty is to cool down and condense air is designed by wall temperature determination method and GA. Then in layer by layer simulation the optimum periodic layer pattern is defined by developed code. With the optimum layer pattern the wall temperature...
A Study on the Thermal Stability and Microstructure of Nanocrystalline Al-Ti(Ni) Alloys Synthesized by Mechanical Alloying
, M.Sc. Thesis Sharif University of Technology ; Maddah Hosseini, Hamid Reza (Supervisor) ; Seyyed Reihani, Morteza (Supervisor)
Abstract
In the present investigation, the mechanical alloying (MA) technique was employed to produce nanocrystalline Al-Ti Powder mixtures. Elemental Al and Ti powders were mixed with different compositions (0, 5, 10, and 20 wt.% Ti) and then, milled in a vibratory mill up to 7 hr. The variations of powder morphology and particle size, apparent and tap densities, microstructure, grain size, lattice strain, and microhardness were studied with increasing the milling time. While dissolution of Ti in the Al matrix resulted to the formation of supersaturated Al-Ti solid solution in the samples containing 5 and 10 wt.% Ti, the specimen with 20 wt.% Ti, eventually, led to nanocomposite powder with...
Microstructure Optimization of In-situ Al-Al3Ti Nanocomposite Fabricated by Mechanical Alloying & Hot Extrusion for Improving the Fracture Toughness
, Ph.D. Dissertation Sharif University of Technology ; Madaah Hosseini, Hamid Reza (Supervisor) ; Seyyed Reihani, Morteza (Supervisor)
Abstract
The aim of this research was to fabricate an in-situ Al-Al3Ti nanocomposite from pure microsized aluminum and titanium powders by mechanical alloying and hot extrusion without any usage of nanometric particles or applying secondary heat treatments. The focus of the present research was fabricating a nanocomposite material with high strength, modulus and hardness accompanied with high fracture toughness that could be comparable with aluminum alloys in terms of fracture toughness. Mechanical alloying and hot extrusion techniques were employed to produce in-situ fully dense Al-Ti composites. Platenary and high energy vibratiory mill was used to produce composites with different percent of...
Ant colony algorithm for the shortest loop design problem [electronic resource]
, Article Computers and Industrial Engineering, Elsevier ; Volume 50, Issue 4, August 2006, Pages 358–366 ; Kazemi, Morteza ; Sharif University of Technology
Abstract
In this paper, a new algorithm for solving the shortest loop design problem is presented. The shortest loop design problem is to find the shortest loop for an automated guided vehicle covering at least one edge of each department of a block layout. In this paper, first it is shown that this problem can be represented as a graph model. The properties of the presented model enable us to design a meta-heuristic based on ant colony system algorithm for solving the shortest loop design problem. Computational results show the efficiency of our algorithm in compare to the other techniques
Modeling Reaction and Distribution of Water in Nanopores of the Cathode Catalyst Layer of PEM Fuel Cell
, M.Sc. Thesis Sharif University of Technology ; baghalha, morteza (Supervisor)
Abstract
In the proton exchange membrane fuel cells (PEM, the produced water would be divided into two phases of vapor and liquid. distribution of both liquid and vapor phases in different cell layers affects the performance, the efficiency and the life of a fuel cell significantly. Moreover, Nano pores of the cathode catalyst layer are involved with some phenomena such as electrochemical reaction kinetics, heat and mass transfer and interface phase change. One of the most important problems in the performance of fuel cells is distribution of liquid water in the porous areas. Water flooding in fuel cells causes to delay in oxygen transport to active sites in the catalyst layer because the pores of...
Love Wave Propagation in a Functionally Graded Magneto-Electro-Elastic Half-Space with Quadratic Variations
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
The propagation behavior of Love wave in functionally graded magneto-electro-elastic half-spaces with a quadratic variation is addressed. The magneto-electromechanical coupling factor, the dispersion relations, electric potential, magnetic potential and displacement are obtained analytically for both magneto-electrically open and short conditions. The effect of gradient coefficient on phase velocity, group velocity and magneto-electromechanical coupling factor are plotted and discussed. Research on the wave propagation in magneto-electro-elastic materials is still very limited. This work provides us with a theoretical foundation to design and practically apply SAW devices with high...
Elastic Analysis of a Surface Stiffened Transversely Isotropic Half-space Under a Buried Horizontal Point Load
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
In this study, the interaction between thin plate completely bonded to the transversely isotropic halfspace and a concentrated force applied horizontally (Mindlin-type force) are considered. This problem has been solved analytically. This problem is used as sample for thin solid films and surface coating technology, where the surface of solid is covered by thethin plate for increasing its stiffness. Moreover, this problem is a good sample when homogenous solid is subjected to contact loading and can be seen that mechanical properties of material which is near the solid surface varies; consequently, a two-phase solid is created.Because of the influence of noted inhomogeneity, solid is...
Modeling and Simulation of the Catalyst Regeneration Process of FCC Unit of Abadan Refinery
, M.Sc. Thesis Sharif University of Technology ; Baghalha, Morteza (Supervisor)
Abstract
Hydrodynamics plays a crucial role in defining the performance of fluidized beds. The numerical simulation of fluidized bed is very important in the prediction of its behaviour. From this point of view, in the present study a dynamic two dimensioanl model is developed for the modeling of regenerator system of a UOP fluid catalytic cracking (FCC) unit of Abadan refinery with a high-efficiency regenerator. Of the various modeling and simulation techniques, computational fluid dynamics (CFD) is employed in this thesis. Effects of gas velocity, the transient local solid volume fraction, pressure drop for gas and solid phase, solid holdup distribution and solid circulation pattern have been...
Secure- multiparty Computation Protocol for Privacy Preserving Data Mining
, M.Sc. Thesis Sharif University of Technology ; Amini, Morteza (Supervisor)
Abstract
Privacy preserving data mining helps organizations and companies not only to deal with privacy concerns of customers and regular limitations, but also to benefit from collaborative data mining. Utilizing cryptographic techniques and secure multiparty computation (SMC) are among widely employed approaches for preserving privacy in distributed data mining. The general purpose of secure multiparty computation protocols to compute specific functions on private inputs of parties in a collaborative manner and without revealing their private inputs. Providing rigorous security proof of secure multiparty computation makes it a good choice for privacy preservation, despite of its cryptographic...
Information-flow Analysis in Android Apps for Protecting User Privacy
, M.Sc. Thesis Sharif University of Technology ; Amini, Morteza (Supervisor)
Abstract
The rapid growth of Android operating system alongside its open-source nature has made it as the most popular operating system of mobile devices. On the other hand, regarding the increasing computational power of mobile devices, a wide variety of applications are coming to this type of devices. Meanwhile unfortunately many malicious softwares trying to keep up with other applications, are targeting this popular operating system. Therefore with regard to the fact that this type of devices usually store private and sensitive information of their users, security of mobile operating systems is considered very important. Having this matter in mind, the goal of this research work has been...