Sharif Digital Repository

Composite film PLA/PVDF and nanocomposite films PLA/PVDF/MWCNT with a solution method by solvent Dimethyl formamide was prepared at 65◦c. poly vinylidene fluoride as matrix phase and poly lacticacid was used an amplifier. In the next sextion multiwalled carbon nanotubes were added to the PLA/PVDF composite.Scaning Electron microscope results, showed that the PLA/PVDF composite and PLA/PVDF/MWCNT nanocomposites, non porous structure and carbon nanotubes in the polymer matrix have been well dispersed. The impact of nanoparticles in the polymer matrix by X-Ray Diffraction and Differential Scaning Calorimetry was investigated. With differential scaning calorimeter (DSC) and stress strain test,... 

The aim of this research is to develop a smart mesoporous bioactive glass-based carrier for targeted drug delivery to cancer cells, particularly bone cancer cells. To achieve this, mesoporous bioactive glass nanoparticles were first synthesized, followed by surface modification with amine groups. To prevent premature drug release before reaching the target tissue and to introduce pH sensitivity, the nanoparticle pores were coated with oxidized hyaluronic acid via Schiff-base bonding with the amine groups on the surface. The use of hyaluronic acid facilitates active targeting of CD44 receptors, which are overexpressed on the surface of cancer cells compared to healthy cells. This process... 

The present work describes sensing application of modified Pt nanostructures towards detection of glucose. Modified Pt nanostructured electrodes were prepared using electrodeposition method such as chronoampermetry and potentiostatic pulse methods. The electrodeposition of Pt nanostructures was first studied by voltammetry and amperommetry techniques and then potentiostatic pulse method has been used to produce the alloyed structures of platinum. In this regard, the first electrode was proposed based on alloyed Pt/Ni nanowire arrays (NWAs) for the non-enzymatic detection of glucose. The Pt/Ni NWAs were prepared by pulse electrodeposition of Pt and Ni within a nano-pore polycarbonate (PC)... 

Any physical system is characterized with some set of quantities or parameters, knowing which, is equivalent to estimation of the system. Evaluating such parameters is usually done using tomography methods. An important question to ask, is how to increase the precision of measurement, being able to do some specific set of physical operations, say, measurement?
this question is more important in parameter estimation in quantum meanical systems. It has been shown that, quantum meanics causes a fundamental limit, on precision of estimating su parameters, escribed by the so called “antum Cramér-Rao bound”.We must note that almost all quantum meanical systems are interacting with the... 

In this study, chitosan-based nanoparticles were prepared due to their biocompatibility, availability, high loading capacity of drug, stimulus responsive behavior and the presence of active functional groups. Chitosan was chemically functionalized with reactive oxygen species (ROS)-responsive moiety to respond to the oxidative stess and endosomal pH in nerve injuries. To prepare nanoparticles, functinalized chitosan ionically gelated with pH-responsive polyanions with ROS-scavenging properties such as polyacrylic acid and hyaluronic acid. Then, pH- and ROS-responsive nanoparticles were used for selective transfection into reactive astrocytes and axonal regeneration in spinal cord injuries.... 

The primary purpose of acidizing operations in the oil and gas industry is to enhance hydrocarbon production. Acidizing has been a common and conventional method for years, especially when production engineers face issues like declining reservoir pressure leading to reduced production rates. Initially, the treatment solution is referred to as matrix acidizing. In acidizing operations, different additives are combined with the acid to control its behavior in the reservoir. These additives may include iron control agents, corrosion inhibitors, friction reducers, and more. Incompatibility among these additives, the acid, and reservoir fluids can lead to severe damage to the reservoir.... 

The goal of this research is the simulation of the annular combustion chamber of the turbine engine utilized by liquid fuel. The achievement to this goal will lead to create numerical tools for parametric study, analysis and combustion chamber designing.For this reason simple geometry has been considered. This simplicity of geometry causes to facilitate in parametric study and decrease in saving time for modeling and meshing. This combustion chamber is a simplified model of engine CF6. In recent study, the k – ε realizable model has been used for turbulence modeling. For non-adiabatic condition, chemical reaction is dissolved by utilizing probability density function along with laminar... 

During the last few years, the study of urban environment structures is considered as a research field of interest in remote sensing. In satellite observations of the earth's surface, continuous imaging in terms of time and space has caused the remote sensing technique to be proposed as a useful and efficient tool for the analysis of urban areas. Obtaining quantitative spatial information from the urban environment in fields such as determining the height of buildings plays an essential role in urban planning, monitoring damage to buildings, establishing communication bases and digital cities. During the last two decades, the use of Tomosar approach in order to reconstruct the structures of... 

In this work, the dynamic competition between firms providing internet services is studied. The framework is Markov equilibrium whereby structural parameters are obtained using two-step estimations, allowing for analyzing the situation in case of subsidies for service upgrade. The results show that such subsidy has little effect on the number of firms while increasing the number of fast firms  

Estimating the price elasticity of gas demand involves complexities depending on the gas market structure and pricing mechanisms in different countries. Distinguishing between supply and demand shocks and block pricing are among the main challenges that can cause endogeneity in elasticity estimates. Iran's domestic gas network, one of the largest and most extensive household gas markets, is divided into five climatic zones based on weather conditions. The pricing steps for these five climates during the five cold months are such that a customer in a warmer climate pays higher prices. Conversely, the pricing steps for the seven warm months are the same for all climates. This policy creates a... 

The correlation between religious adherence and voter turnout is widely studied. However, whether the relation is causal is an open question. We use Household Expenditures and Income Survey (HEIS) data in Iran, which encompasses nine distinct religious expenditures. These expenditures have low correlation with each other and represent different aspects of religious adherence. We use Imamzadeh (some historical holy shrines) as Instruments to estimate the causal effect of religious expenditures on voter turnout. The results reveal that religious expenditures influence both presidential and parliamentary voter turnout, with a notably stronger impact on presidential elections  

Mobile edge computing (MEC) is a promising technology that aims to resolve cloud computing’s issues by deploying computation resources at the edge of mobile network and in the proximity of users. The advantages of MEC include reduced latency, energy consumption, and load on access and mobile core networks, to name but a few. Despite all the aforementioned advantages, the mobility of mobile network users causes the traditional MEC architecture to suffer from several issues, such as decreased efficiency and frequent service interruption. One of the methods to manage users’ mobility is virtual machine (VM) migration, where the VM containing the user’s task is migrated to somewhere closer to... 

In this study TiO2/SiO2 thin films were prepared by sol-gel method from Tetra isopropylortho Titanate(TIPT) as the principle of TiO2 material with Tera ethoxysilane(TEOS) as the principle of SiO2 material to achieve high scratch-resistant , antibacterial and self-cleaning surface area under the effect of various percentage of SiO2 . Film deposition was carried out using a dip-coating technique and heat-treatment was used at 700ºC to achieve crystalline of films with excellent adherence the of substrate.
The surface morphology of the films has been observed by Scanning Electron Microscope (SEM) and the tribological properties of the surface were investigated by Atomic Force Microscope... 

In this study steady state and dynamic simulation of an NFM extractive distillation unit for seperation of aromatics and non-aromatic components has been carried out. Column output composition obtained with experimental binary coefficients is compared with those obtainded by UNIFAC equation. The results indicate that using UNIFAC for all binrary coefficients results in an unacceptable error in concentration of benzene. If the experimental binary coefficents of benzene with NFM are used and the rest are calculated by UNIFAC equation, the simulation results will be very close to those obtained via experimental binary coefficients. Also it is shown that considering a constant efficiency for all... 

Nowadays, with population growth and vehicle traffic increase, only providing transportation supply couldn’t answer the transportation demand. One of the most important solutions to reduce traffic is transportation demand management (TDM). In this research, the effects of parking pricing and improving public transportation services on private car demand reduction in city center are examined. The data are collected from private cars users in the city center of Isfahan through interviews. By stated preference method, the impacts of parking price and public transit travel time and other related factors were investigated. For this purpose, binary logit, multinomial logit and nested logit models... 

Industrialization has brought about air pollution which is one of the most important factors threatening human health. The most efficient method to improve air quality include preventing the emission of pollutants by making laws and regulations. In order to set appropriate regulations, there needs to be a correct understanding of the problem. The purpose of this research is to identify such factors and create a correct understnding of the problem in Iran by constructing a Model of Iranian air qulity. The model used in this research, CMAQ is one of the most comprehensive and state of the art models in transport of pollutnts and chemical reactions in the atmosphere. The inputs into CMAQ...