Investigation into Circular Steel Tubes with Pitting Corrosion under Axial Compression and Bending Moment

, M.Sc. Thesis Sharif University of Technology Salehi, Nazanin Fatemeh (Author) ; Moazezi Mehretehran, Alireza (Supervisor)

Abstract

In this research the behavior of Circular Steel Tubes (CSTs) with corrosion under axial force and bending have been studied. There are several factors leading to corrosion in steel structures, especially marine structures that results in strength reduction of whole structure. Steel tubes are widely used in construction of on-shore and off-shore structures such as, oil rigs and platforms, oil and gas transmission lines. Current study focus on strength reduction of steel tubes with “pitting corrosion”. To this end numerical analyses using finite element software, Abaqus, have been performed. Therefore, utilizing verified models, the simultaneous effect of bending, axial load and corrosion on...

Seismic Isolation of Structures using Trench Barriers

, M.Sc. Thesis Sharif University of Technology Gharegozloo, Amir Hossein (Author) ; Kazemi, Mohammad Taghi (Supervisor)

Abstract

Ground vibration induced by human activity such as industrial activities, Blasting, in construction or deconstruction operation. Ground vibration reaches the troublesome limit for men. In the densely populated urban regions and buildings housing, ground vibration has to be strictly controlled. Many vibration reduction methods have been proposed.A metod of protecting structures from dynamic loads is using trench wich will be located between the dynamic sources and the protected structures. Inappropriate designing of trenches will reduce its effect. In this research the effect of trenches and their different properties, such as type of material, width, trench depth, soil bed type and distance...

Preparation of Metal Nanoparticles/Ionic Liquid Composites and Investigation of Their Catalytic Activity

, M.Sc. Thesis Sharif University of Technology Gharegozloo, Nazanin (Author) ; Gholami, Mohammad Reza (Supervisor) ; Salari, Hadi (Co-Advisor)

Abstract

In this research Fe3O4 magnetic nanoparticles were prepared. To protect against oxidation, a shell of SiO2 was deposited on Fe3O4. Graphene oxide was prepared by the modified Hummer method and supported on the Fe3O4@SiO2 core-shell. Then, ionic liquid layer was impregnated on it. Afterward, PtAu nano alloy were synthesized on the surface of nanocomposite with the different molar ration including 100:0, 75:25, 50:50, 25:75 and 0:100. The as-prepared nanocomposite was characterized by SEM, XRD, and FT-IR analytical methods.For investigation of kinetically activity of catalysts, reduction of 4-nitrophenol with NaBH4 as reducer was used. The adsorption in different times was obtained by UV-vis...