Characterzing Variation of Small Strain Shear Modulus of Unsaturated Sand During Hydraulic Hysteresis with Bender Elements

, M.Sc. Thesis Sharif University of Technology Shahbazan, Parisa (Author) ; Pak, Ali (Supervisor) ; Khosravi, Ali (Supervisor)

Abstract

Results of previous studies on silt and clay indicated that variations in the small strain shear modulus, Gmax, during drying had a non-linear increasing trend with matric suction with greater values upon wetting. However, due to different material properties and inter-particle forces, different behaviour in Gmax is expected for sand. Although considerable research has been devoted in recent years to characterize the behaviour of Gmax of sand during drying, rather less attention has been paid to the effect of hydraulic hysteresis on Gmax and its variations during wetting. In the study presented herein, an effort was made to characterize the variation of Gmax for specimens of sand during...

Characterizing the variation of small strain shear modulus for silt and sand during hydraulic hysteresis

, Article 3rd European Conference on Unsaturated Soils, 12 September 2016 through 14 September 2016 ; Volume 9 , 2016 ; 22671242 (ISSN) Khosravi, A ; Rahimi, M ; Shahbazan, P ; Pak, A ; Gheibi, A ; Sharif University of Technology

EDP Sciences 2016

Abstract

Experimental studies have indicated that the small strain shear modulus, Gmax, of unsaturated silt and clay has a greater amount during imbibition than during drainage, when presented as a function of matric suction. However, due to material properties and inter-particle forces, different behavior is expected in the case of sand. Although considerable research has been devoted in recent years to characterize the behaviour of Gmax of sand during drainage, rather less attention has been paid to the effect of hydraulic hysteresis on Gmax and its variations during imbibition. In the study presented herein, an effort has been made to compare the Gmax behavior of specimens of silt and sand during...

Experimental Study of Drying and Calcination of Simulated High-Level Waste (HLW)

, M.Sc. Thesis Sharif University of Technology Farahzadi, Zahra (Author) ; Samadfam, Mohammad (Supervisor) ; Zahakifar, Fazel (Supervisor) ; Zaheri, Parisa (Co-Supervisor)

Abstract

One of the novel methods of stabilization of nuclear waste is the use of vitrification technology. In order to stabilize high level wastes (HLLW) in glass, it is required that the elements are in their oxide form. Therefore, it is necessary to evaporate the waste and turn it into a solid form so that the elements can be converted into oxide form in the calcination furnace. Hence, one of the challenges of stabilization is the optimization of evaporation and calcination conditions. In this research, the parameters affecting evaporation were first investigated. Using laboratory measurements of application: temperature (110 to 180 °C), presence of nitric acid (0.5 to 4 mol/L), ratio of zirconium...

The Study of Effective Parameters on Thorium Extraction by Cyanex 272 in an Emulsion Liquid Membrane System

, M.Sc. Thesis Sharif University of Technology Ehyaie, Darya (Author) ; Samadfam, Mohammad (Supervisor) ; Zaheri, Parisa (Supervisor) ; Zahakifar, Fazel (Co-Supervisor)

Abstract

This study used the emulsion liquid membrane method to investigate the extraction and separation of thorium from nitrate solution. According to the results obtained from the studies, Cyanex 272 was a suitable option for selectively extracting thorium. For simultaneous extraction and stripping of thorium from dilute aqueous solutions, an emulsion liquid membrane system consisting of Cyanex 272 as an extractant, Span 80 as a surfactant and sulfuric acid solution as a receiving phase (internal phase) was used. Emulsion liquid membrane method has high mass transfer flux due to high surface to volume ratio, which causes high extraction efficiency and fast transfer of thorium ions from its low...

Fabrication Patient-Specific Drill Guide Templates for Cervical Pedicle Screw Placement

, M.Sc. Thesis Sharif University of Technology Safahieh, Amir Hossein (Author) ; Arjmand, Navid (Supervisor) ; Parnianpour, Mohammad (Supervisor) ; Azimi, Parisa (Co-Supervisor)

Abstract

One of the most common spinal surgeries involves spinal fusion or vertebral fixation, which is used to treat various conditions such as intervertebral disc disease, scoliosis (lateral deviation of the spinal column), fractures, infections, or the presence of tumors in the spinal column. In this surgical procedure, the use of pedicle screws and titanium rods prevents motion and friction between two vertebrae. Screws may enter the vertebrae in the wrong position and angle, causing bone weakening, rupture of nerve roots or blood vessels, weakness or lack of sensation in some parts of the body, spinal cord injury, and in severe cases, paralysis of the patient. For this reason, fusion surgery is...

Investigation of Mass Transfer Coefficients in Lithium Liquid-Liquid Extraction Process in Batch and Continuous Modes (Microchannel)

, M.Sc. Thesis Sharif University of Technology Bahadri, Mohammad Mehdi (Author) ; Otokesh, Mohammad (Supervisor) ; Amari Allahyari, Sareh (Supervisor) ; Zaheri, Parisa (Co-Supervisor)

Abstract

Lithium is a soft, silvery-white alkali metal that is recognized as the lightest metal and the least dense solid element. The increasing demand for lithium, driven by the global shift towards electrification and sustainable energy solutions, has transformed this material into a crucial resource in the modern economy. Lithium has applications in various industries, including the nuclear industry. 6Li is used for the production of tritium, and 7Li, in the form of 7LiOH, is used to adjust the pH in light water reactors and as an anti-corrosion compound in fission reactors. In this study, the extraction of lithium from the aqueous phase using a Y-shaped microchannel was carried out, and the mass...