Electronic Polarization Controller

, M.Sc. Thesis Sharif University of Technology Bakhtiary, Pooryia (Author) ; Bahrampour, Alireza (Supervisor)

Abstract

In quantum communication,polarization degree of freedom is of particular importance, as polarization is used in many quantum key sharing protocols. During the transmission of photons, the polarization may be affected by environmental factors and change, for exam- ple, changes in tension and temperature disturb the polarization. In this thesis, methods of compensation for polarization change is investigated like by applying electric field, mag- netic field, strain,also a review of methods of measuring polarization disturbance and its compensation in quantum transmission lines, especially fiber optics, design and construction of compensators (electrical polarization controllers), based on...

Numerical Study of the Behaviour of Cruciform Columns Under Axial Compression

, M.Sc. Thesis Sharif University of Technology Bakhtiary, Ahmad Reza (Author) ; Khansari, Vahid (Supervisor)

Abstract

Due to restrictions on connecting beams to columns in steel structures when moment-resisting connections in two perpendicular directions are employed, the use of ordinary wide-flange sections or fabricated boxes becomes impractical. Application of Cruciform sections, especially when fabricated from two split-I sections (IPE sections) seems to be a reasonable solution to this problem. In this study, using Finite Elements Method and a commercial FEM software, the nonlinear behaviour of a number of cruciform columns, already tested by others, were modeled numerically. After reaching results in acceptable agreement with those of the tests, potentially suitable sections for fabrication of...

An Investigation on the Deformation of a Near Euectic Al-Si Alloy Using the ECAE Process

, M.Sc. Thesis Sharif University of Technology Bakhtiary Davijani, Amir Hamed (Author) ; Karimi Taheri, Ali (Supervisor)

Abstract

The use of aluminum and its alloys in different industries is increasing. To increase the deformability of Aluminum alloys, it is usually deformed at high temperatures. In Such working conditions, the chemical composition, temperature of deformation, strain rate and high temperature activating phenomena will affect the microstructure and final properties of the material. In this thesis the hot and cold deformation behavior of a Al-11.77%Si-0.2%Mg are evaluated. In the cold deformation, the alloy was first annealed and then ECAEed. The mechanical properties and the related microstructure were evaluated via the microhardness test. The results indicated that the alloy could not be deformed...

Comparison of transplantation of bone marrow stromal cells (BMSC) and stem cell mobilization by granulocyte colony stimulating factor after traumatic brain injury in rat

, Article Iranian Biomedical Journal ; Volume 14, Issue 4 , Oct , 2010 , Pages 142-149 ; 1028852X (ISSN) Bakhtiary, M ; Marzban, M ; Mehdizadeh, M ; Joghataei, M. T ; Khoei, S ; Pirhajati Mahabadi, V ; Laribi, B ; Tondar, M ; Moshkforoush, A ; Sharif University of Technology

2010

Abstract

Background: Recent clinical studies of treating traumatic brain injury (TBI) with autologous adult stem cells led us to compare effect of intravenous injection of bone marrow mesenchymal stem cells (BMSC) and bone marrow hematopoietic stem cell mobilization, induced by granulocyte colony stimulating factor (G-CSF), in rats with a cortical compact device. Methods: Forty adult male Wistar rats were injured with controlled cortical impact device and divided randomly into four groups. The treatment groups were injected with 2 × 106 intravenous bone marrow stromal stem cell (n = 10) and also with subcutaneous G-CSF (n = 10) and sham-operation group (n = 10) received PBS and "bromodeoxyuridine...