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In-vitro evaluation of thermoplastic starch/ beta-tricalcium phosphate nano-biocomposite in bone tissue engineering
, Article Ceramics International ; Volume 47, Issue 11 , 2021 , Pages 15458-15463 ; 02728842 (ISSN) ; Bagheri, R ; Taherimehr, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Thermoplastic starch (TPS), as a natural based polymer, is known to have the capability to be used in biological applications due to its biocompatibility and biodegradability. In this study, mechanical properties of TPS are enhanced by incorporating bioactive β-tricalcium phosphate (β-TCP) particles for bone tissue engineering applications. Starch-based nanocomposites containing 3, 5, and 10 wt% of β-TCP nanoparticles (TT3, TT5, TT10) were made using a co-rotating twin-screw extruder. Dynamic light scattering (DLS) and X-ray diffraction (XRD) techniques were employed to analyze the nanocomposites. Moreover, degradability, swelling degree, and biomineralization in a simulated body fluid (SBF)...
Mathematical Modeling and Simulation of Tumor Angiogenesis
, M.Sc. Thesis Sharif University of Technology ; Fotouhi, Morteza (Supervisor)
Abstract
A major medical revolution that is helping us overcome some of the worst diseases, including cancer, is angiogenesis, which is based on the processes our bodies use to develop blood vessels. Most human cancers have acquired six essential capabilities: self-sufficiency in growth signals, insensitivity to growth-inhibitory signals, programmed cell death escape, unlimited replication potential, persistent angiogenesis, and tissue invasion that can induce metastasis. In other words, the defense mechanism that prevents any of these acquired capabilities must be neutralized before the cells become malignant and invasive tumors. In fact, tumors in the non-vascular growth stage can only grow up to...
Trends and challenges of biopolymer-based nanocomposites in food packaging
, Article Comprehensive Reviews in Food Science and Food Safety ; Volume 20, Issue 6 , 2021 , Pages 5321-5344 ; 15414337 (ISSN) ; YousefniaPasha, H ; Tabatabaeekoloor, R ; Pesaranhajiabbas, E ; Sharif University of Technology
John Wiley and Sons Inc
2021
Abstract
The ultimate goal of new food packaging technologies, in addition to maintaining the quality and safety of food for the consumer, is to consider environmental concerns and reduce its impacts. In this regard, one of the solutions is to use eco-friendly biopolymers instead of conventional petroleum-based polymers. However, the challenges of using biopolymers in the food packaging industry should be carefully evaluated, and techniques to eliminate or minimize their disadvantages should be investigated. Many studies have been conducted to improve the properties of biopolymer-based packaging materials to produce a favorable product for the food industry. This article reviews the structure of...
Network Analysis of EEG Data of Alzheimer’s Disease
, M.Sc. Thesis Sharif University of Technology ; Jalili, Mahdi (Supervisor)
Abstract
Recently complex networks, have been widely used as a model to study the behavior of human brain. By affecting different parts the brain, Neuronal disorders change the structure of functional brain networks. Investigating these changes using different graph theory metrics can be a useful methodology for human brain analysis in health and disease. Alzheimer's disease (AD) is a neural disease causing impairment in different brain activities including memory and cognition.The aim of this study is to construct the functional brain network of 17 AD patients and 17 healthy control subjects at resting state condition and analyzing them using the theory of complex networks in order to achieve a...
Driving of Quantum Hamiltonian Relative to The One Dimentional Cavity With Oscilating Mirror and Semi-Transparent Mirror
, M.Sc. Thesis Sharif University of Technology ; Bahrampour, Alireza (Supervisor)
Abstract
The concept of entanglement exists in the common area of the quantum optics and quantum information. Quantum optics is the best tools for investigating of this quantum informational phenomenon experimentally. One of the instruments that let us observes experimentally macroscopy entangeled state is Fabry-Perot Cavity. Striking of photons with the mirror of cavity transfer effective mommentom to it, and oscilating of mirror creates new modes: stocks and anti-stocks modes. Studing quantum state of these modes shows the entangling between photon and phonon (oscilating of mirror) modes. We assume that light beam enters the cavity from a semi-transparent mirror. So cavity is the system with...
Qualitative Study of the Dynamic Adsorption Layer by Bubble Rising Method
, M.Sc. Thesis Sharif University of Technology ; Bastani, Dariush (Supervisor) ; Lotfi, marzieh (Co-Advisor)
Abstract
Surface phenomena and dynamic interfacial properties plays a significant role in multiphase gas-liquid & liquid-liquid processes applied in different industrial applications. However, current laboratory equipment and represented methods for dynamic and unsteady state condition caused by motivation of interface of two phases (like rising bubble), in purpose of qualitative investigation of interphase properties are not satisfying enough. Also, common modeling methods are represented with lots of modified assumptions which are not validated properly with experimental results. In current thesis, with development of laboratory tools and applying the “rising bubble method” for investigating the...
Global Control of Hybrid Microgrids Using MIMO Control
, M.Sc. Thesis Sharif University of Technology ; Mokhtari, Hossein (Supervisor)
Abstract
Given the growing advantage of exploiting renewable energy resources over fossil fuels and using distributed generation systems, microgrids seem to be the best solution for reaching the energy-efficient world of the future. Hybrid microgrids are the best options among all other types of microgrids because they make it possible to use AC and DC sources and loads together and at the same time. Since connecting AC and DC sections of a hybrid microgrid leads to the interaction between them, proper control of interlinking converter(s) is crucial for the reliable and stable operation of the entire microgrid. In this study, small signal model of a hybrid AC/DC microgrid consisting of static and...
Non-Equilibrium Interfacial Behavior of Dynamic Interfaces in Presence of Surfactants and Nanoparticles; Experimental and Computational Fluid Dynamic Investigations
, Ph.D. Dissertation Sharif University of Technology ; Bastani, Dariush (Supervisor) ; Lotfi, Marzieh (Supervisor)
Abstract
The present study has been performed for better understanding about the dynamic behavior of fluid interfaces in presence of surfactants, nanoparticles and their interactions in gas-liquid dispersion systems. One of the main purposes of this work is to investigate the influence of surface modified nanoparticles on the dynamic behavior of gas-liquid interfaces. For this purpose, the rising bubble experiment was used as one of the most conventional procedures. Local velocities of bubbles rising in nanoparticle solutions were determined experimentally. Influences of silica nanoparticles which were modified via three approaches were investigated in these experiments. Heat treatment was applied to...
Evaluation of Nanobiocomposite Based on Thermoplastic Starch for Bone Tissue Engineering Applications
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza (Supervisor) ; Maddah Hosseini, Hamid Reza (Supervisor)
Abstract
Development of new engineered materials for bone tissue engineering applications is rapidly growing. The most important characteristics of materials, which can be used for bone tissue engineering applications, are appropriate mechanical properties, degradation rate, swelling behavior, and bioactivity. The goal of the current investigation is to study the feasibility of incorporating a modified nano-biocomposite based on biodegradable thermoplastic starch for bone tissue engineering. Nano particles of ?-tricalcium phosphate and hydroxyapatite were incorporated for reinforcing the matrix as well as improving the bioactivity. A second biodegradable polymer, i.e. polycaprolactone, was used...
Investigation of the Liquid Viscosity Effect on the Rising Bubble Motion (Effect of Ethylene Glycol Concentration on Terminal Velocity)
, M.Sc. Thesis Sharif University of Technology ; Bastani, Dariush (Supervisor) ; Lotfi, Marzieh (Co-Advisor)
Abstract
Surface phenomena is one of the fundamental branches of science that has many applications in industries related to multiphase processes. One of the most important issues of this knowledge is inter-phase transport phenomena in contacting gas - liquid and liquid – liquid systems. Multiphase systems generally include dispersions such that in many cases are associated with the relative motion between the continuous and dispersed phase. One of the most widely used inter-phase flow systems is dispersion of gas bubbles in the bulk of liquid. The overall efficiency of these systems is often determined by the characteristics of the gas phase. In order to understand the dynamic behavior of such...
Theoretical Investigation of Quantum Optical Amplifiers in Quantum Communications
, M.Sc. Thesis Sharif University of Technology ; Bahrampour, Alireza (Supervisor) ; Bathaee, Marzieh Sadat (Co-Supervisor)
Abstract
Signal transmission of information on noiseless and lossy channels is an important issue in data transmission. Using the amplifier in the transmission channels is a good solution to help send information on longer channels. In classical communication, information can be coded in the amplitude or phase of the field and an amplifier is responsible for amplifying these parameters. If we consider the conditions ideal and ignore electrical noises, Classical mechanics does not impose any restrictions on the amplification of arbitrary classical signals. Instead, in quantum telecommunications the information encoded on the quadrature of the electromagnetic field are mounted on quantum states, such...
Examining the Impact of Key Factors on Esteghlal Tehran Fans' Intention to Attend Matches: A Social Identity Theory Perspective
, M.Sc. Thesis Sharif University of Technology ; Alavi, Babak (Supervisor) ; Saghafian, Marzieh (Supervisor)
Abstract
This study investigated the relationships between team identification and attendance intention in Iranian football matches, specifically examining the impact of constraints on this relationship. The research focused on Esteghlal Football Club, one of Iran's most popular teams, which faces a paradox of having a large fan base (35-40 million supporters) but relatively low stadium attendance rates (below 50% capacity). The study employed a mixed online sampling method (convenience and snowball) with 182 Esteghlal fans who had attended at least one stadium match. Data was collected using three validated questionnaires: team identification (18 items, 6 dimensions), attendance intention (4 items,...
Investigating the Mathematical Model of Transformers in Deep Learning Using the Self-Attention Mechanism in Multi-Layer Neural Networks
, M.Sc. Thesis Sharif University of Technology ; Bahraini, Alireza (Supervisor) ; Shams Yousefi, Marzieh (Supervisor)
Abstract
This dissertation is organized into three chapters. The first chapter presents the necessary concepts and theorems. The second chapter addresses the primary objectives of the study. The third chapter is devoted to the proof and analysis of the convergence theorem for the attention matrix to low-rank Boolean matrices. The objective of this thesis is to investigate the mathematical model of the selfattention mechanism in deep learning, which is examined through the lens of optimal transport theory. It includes two theorems concerning clustering and the convergence of solutions to the differential equation describing the self-attention mechanism.
Evaluation of Exerted Drag Force on Alkane Saturated Air Bubbles in Aqueous Solutions by Experimental Studies
, M.Sc. Thesis Sharif University of Technology ; Bastani, Dariush (Supervisor) ; Lotfi, Marzieh (Supervisor)
Abstract
Interfacial phenomena and properties of interphase surfaces in dynamic mode play an important role in industrial processes that include gas-liquid and liquid-liquid multiphase flows. As well as, interface knowledge leads to better understanding of natural and fundamental phenomena. The present study has been performed for understanding about dynamic behavior of interphase surfaces in the presence of nanoparticles and hexane vapor in gas-liquid dispersion systems. In this research, rising bubble method has been used as one of the most conventional techniques. Accordingly, aqueous solutions of nanosilica were prepared in concentrations of 50, 100, 200, 400 and 1200 ppm as continuous phase...
Application of Cellulose Nanofibers Coated Quartz Crystal Microbalance (QCM) Biosensor for Amino Acid Detection in Aqueous Media
, Ph.D. Dissertation Sharif University of Technology ; Irajizad, Azam (Supervisor) ; Vossoughi, Manouchehr (Supervisor)
Abstract
Developing a simple, cost effective and accurate detection method for L-lysine (Lys), L-leucine (Leu) and glycine (Gly) as the important analytes in clinical diagnostics, biological processes and food industries is of great interest. Therefore, in the first part of this research, cellulose nanofibrils (CNFs) were coated on a quartz crystal microbalance (QCM) surface by spin coating to achieve a QCM biodetector for Gly. Thus, the two-layer CNFs coating was selected as sensing film and was applied for following experiments. In the next step, the coated QCMs were carefully characterized before and after interaction with Gly using water contact angle (WCA), Fourier transform infrared...
Application of Cellulose Nanofibers Coated Quartz Crystal Microbalance (QCM)Biosensor for Amino Acid Detection in Aqueous Media
, Ph.D. Dissertation Sharif University of Technology ; Iraji Zad, Azam (Supervisor) ; Vossoughi, Manouchehr (Supervisor)
Abstract
Developing a simple, cost effective and accurate detection method for L-lysine (Lys), L-leucine (Leu) and glycine (Gly) as the important analytes in clinical diagnostics, biological processes and food industries is of great interest. Therefore, in the first part of this research, cellulose nanofibrils (CNFs) were coated on a quartz crystal microbalance (QCM) surface by spin coating to achieve a QCM biodetector for Gly. Thus, the two-layer CNFs coating was selected as sensing film and was applied for following experiments. In the next step, the coated QCMs were carefully characterized before and after interaction with Gly using water contact angle (WCA), Fourier transform infrared...
Investigation of Dynamic Behavior of Interface by Simulation of New Experimental Method
, M.Sc. Thesis Sharif University of Technology ; Bastani, Dariush (Supervisor) ; Safekordi, Ali Akbar (Supervisor) ; Lotfi, Marzieh (Co-Advisor)
Abstract
Surface phenomena and dynamic Interfacial properties play an important roles in gas- liquid and liquid-liquid multiphase process from various industrial applications to understand fundamental phenomena. However, there is no experimental equipment and efficient methods for quantitative and detail investigation of interfacial properties under fast and non-equilibrium dynamic condition due to mobility and refreshing of interface (such as rising bubble). Also existing models accompanied with a lot of simplifications which is not yet validated with a proper experimental data. development of laboratory equipment base on measuring momentary capillary pressure and presenting a new experimental...