Sharif Digital Repository

The present work describes sensing application of modified TiO2 nanotubes towards detection of dopamine. The TiO2 nanotubes electrode was prepared using anodizing method at different conditions, among which NaF/ NaHSO4 solution and voltage of 15 V was chosen as the optimum condition. In order to improve the performance, surface modification with metal nanoparticles (Pd, Pt and Au) and carbon is required using “pulse electrodeposition” and “decomposition of polyethylene glycol at 600 °C” respectively. Carbon was deposited by decomposition of polyethylene glycol in a tube furnace to improve the conductivity. In this regard two type of electrodes were proposed: Pd-Pt-Au-TiO2 and C-Ni(Pt)-TiO2.... 

The sponge iron of the Hoganas process have a high metallization degree (93-96%) and its carbon content is about 0.1%. These characteristics are suitable for powder metallurgy but in order to use this DRI for steelmaking, it needs lower metallization degree and higher content of carbon. First, for using Hoganas sponge iron for steel production, 94% of metallization is adequate as some of iron is still in the form of FeO which its reduction in Electric Arc Furnace (EAF) cause better agitation in order to utilize heat transfer. Also, excess carbon content in the DRI can have many advantages other than preventing the sponge iron from re-oxidation. Some of the carbon can be in the form of Fe3C... 

The use of superhydrophobic surfaces is one the most promising methods for reducing the friction and increasing the flow rate in fluid transfer systems. Since in such systems the surface structure plays a key role, in the first part of this study, the performance of the hierarchical nanostructures is explored. These nanostructures are inspired by the superhydrophobic surface of the lotus leaf. The flow is considered between two walls with hierarchical nanostructures and simulate the system via the molecular dynamics (MD) method. The size of the nanostructures and the distance between them have been studied to find whether a design with maximum flow rate exists. The nanostructures have two...