Sharif Digital Repository

In this study, after electrodeposition of bimetallic Au-Pt nanoparticles on indium tin oxides (ITO) substrates the optical and electrochemical characteristics of obtained electrodes have been investigated. Moreover, the sensory properties of aquired electrodes toward Hg(II) and Cr(VI) detection has been also studied. The effect of various electrodeposition conditions on obtained nanoparticles have been studied through scanning electron microscopy (SEM) studies. The surface topography, surface roughness and particle size distribution of resulted Au-Pt nanoparticles after electrodeposition were also investigated by scanning Probe Microscopy in its NC-AFM mode. However, the nucleation of Au... 

In recent years, application of silica nanoparticles for wettability alteration of reservoir rocks as an effective approach in enhancing oil recovery from petroleum reservoirs is introduced. However, in this area, lack of fundamental studies to provide a clear understanding about the interaction between these nanoparticles and carbonate rocks (as the predominant reservoir rocks in the world and Iran), which is of particular importance, is sensed. Therefore, the main purpose of this dissertation is to present a mechanistic investigation about the interaction of silica nanoparticles (the most used nanoparticles) with carbonate rock from theoretical and experimental viewpoints. To better... 

Ocean waves are a huge, renewable energy resource, and the potential for extracting energy from waves is high. So a lot of different systems have been designed but most of them are hydraulically and have a lot of problems and they are very complex. In this thesis, the mechanism designed is purely mechanical and very simple and innovative. It has some gears in special combination with together. The mechanism can convert any form of oscillation to rotation movement; this event has been shown in results and prototype. According to the results and discussion, Designed mechanism needs very low maintenance and has low lost. So, efficiency is between 80-95%  

In this project Ni-SiC nanocomposite coatings were electrodeposited using Watts nickel bath with addition of SiC particles to the bath. Optimization of Ni-SiC electrodeposition parameters was done using Response Surface Methodology (RSM). At specific conditions, 67 Vol% of 10nm SiC is incorporated in nickel electrodeposits which is unique and not yet reported. Study nanomechanical properties of these coatings using Nanoindentation method, it was realized that the dislocation density is increased as force increasing which is in agreement with increasing intensity of (220) and (200) reflections and intensity attenuation of (111) reflection. Nanoscratch tests show that these... 

Oil and gas reservoirs in various parts of the world have declined over time, despite a high percentage of oil. Due to the increasing need for hydrocarbon resources, the need for more cost-efficient harvesting methods and less environmental damage is felt. Injection of saline water is one of the most cost-effective ways of harvesting due to the need for no expensive additives. On the other hand, microscopic glass modeling can be used to better understand and understand the performance of saline water at the microscopic scale. In this study we have been able to visualize the effective factors in infusion of saline water. Improved interfacial tensile and particle migration in kaolin-coated...