Sharif Digital Repository

This research aimed at production of Cu-rGO via the combination of Molecular-Level-Mixing (MLM) method and powder metallurgy route (PM). First, Cu-GO composite powder was produced via MLM method. Subsequently, the resultant powder was mixed with electrolytic copper powder.Synthesis process included adjustment of the solution containing copper sulfate and 2Na.EDTA using NaOH solution. In the next step, GO suspension was added to the aforementioned solution. Finally, reduction of copper powder and formation of nanocomposite powder completed via the addition of Sodium Borohydrate. Nanocomposite powder was washed and dried in vacuum oven in 70˚C. GO reduction process took place using a tube... 

Nowadays, metallic microsystems such as miniature and meso-scale gears, microgrippers, and comb structures constitute a significant portion of key components in various microelectromechanical systems (MEMS). Due to their extremely lightweight nature, small size, high dimensional accuracy, superior performance, and extended lifetime, the manufacturing process of these microsystems has always been a subject of discussion and research. The goal is to enhance the strength and precision of the products while reducing production costs.LIGA and wire-cut electrical discharge machining (WEDM) are two well-known methods for fabricating microstructurs. Despite their advantages, such as high dimensional... 

Assessing the seismic loss incurred by structures post-earthquake, or to evaluate structural performance vis-à-vis potential seismic events, constitutes an imperative and pivotal measure for informed decision-making geared towards enhancing community resilience. However, large-scale assessments targeting risk analysis at citywide levels necessitate significant temporal and computational resources. To expedite this process and mitigate associated costs, this study introduces a machine learning-based methodology for estimating seismic loss and repair time of special steel moment-resisting frames. Six distinct machine learning models were trained based on results derived from nonlinear time... 

In high seismically active regions, such as Iran, shear walls are one of the preferred seismic force resisting system.The efficiency of reinforced concrete bearing walls for resisting lateral forces and controlling lateral drift in high-rise buildings has long been recognized. But in recent decades shear wall dominant buildings or so called tunnel form buildings have been increasingly constructed as the multi-story reinforced concrete buildings. The purpose of this thesis is to assess the seismic performance of concrete shear walls that provide gravity as well as sesmic resistance for this kind of buildings. The studied walls were assumed to be part of 5- 10- 20- and 40- story residential... 

The fascinating size-dependent properties of noble metal nanop articles have created a great promise for their use in a different applications specially chemical sensing. Gold nanorods (GNRs), specifically, have received a great deal of attention due to their unusual optical properties. The nanoscale confinement of electrons on the surface of gold nanorods grants them aspect ratio-dependent properties not seen in larger particles. Due to the intriguing properties of GNRs, significant work has gone into the application of nanorods for sensing and detection of various an alytes in biological and other systems. The major modalities which have been developed for... 

There is a growing interest in developing high-performance sensors monitoring organophosphate pesticides, primarily due to their broad usage and harmful effects on mammals. In the first part of this research, by introducing conditional sensor elements (CSE), a colorimetric sensor array has been proposed for the detection and discrimination of several organophosphate pesticides (OPs). citrate-capped 13 nm gold nanoparticles (AuNPs) at nine different pH/ionic strengths were employed as simple plasmonic sensing elements in the development of a colorimetric sensor array for the detection and discrimination of five organophosphate pesticides, including azinphos-methyl (AM), chlorpyrifos (CP),...