Quasi-static Response of an Isotropic Half-space Saturated with Viscous Fluid based on the Theory of Porous Media

, M.Sc. Thesis Sharif University of Technology Behboodi, Mohammad Ali (Author) ; Eskandari, Morteza (Supervisor)

Abstract

The purpose of this study is to apply the governing equations of the theory of porous media with the concept of volume fractions to calculate the isotropic half-space responses subjected to a surface and asymmetric loading and to compare the responses with Biot’s theory. For this purpose, each of the components is first considered continuous and the equilibrium equations of mass and momentum for the solid and fluid phases based on the mixture theory are expressed. The concept of volume fractions and the effect of interaction between the two phases, distinguish these equations from the equations of the continuum theory. Thus, the governing coupled partial differential equations of the theory...

Jitter-buffer management for VoIP over wireless LAN in a limited resource device

, Article 4th International Conference on Networking and Services, ICNS 2008, Gosier, 16 March 2008 through 21 March 2008 ; 2008 , Pages 90-95 ; 076953094X (ISBN); 9780769530949 (ISBN) Baratvand, M ; Tabandeh, M ; Behboodi, A ; Fotowat Ahmadi, A ; Sharif University of Technology

2008

Abstract

VoIP over WLAN is a promising technology as a powerful replacement for current local wireless telephony systems. Packet timing Jitter is a constant issue in QoS of IEEE802.11 networks and exploiting an optimum jitter handling algorithm is an essential part of any VoIP over WLAN (VoWiFi) devices especially for the low cost devices with limited resources. In this paper two common algorithms using buffer as a method for Jitter handling are analyzed with relation to different traffic patterns. The effect of different buffer sizes on the quality of voice will be assessed for these patterns. Various traffic patterns were generated using OPNET and Quality of output voice was evaluated based on ITU...

Synthesis of Hydroxyapatite Nanoparticles through Sol-Gel Method and Fabrication of Chitosan/Hydroxyapatite Scaffold for Bone Replacement Tissue

, M.Sc. Thesis Sharif University of Technology Behboodi, Panteha (Author) ; Nemati, Ali (Supervisor) ; Faghihi Sani, Mohammad Ali (Co-Supervisor)

Abstract

Hydroxyapatite is the most substantial inorganic component of bone tissue which displays great biocompability and bioactivity. Nevertheless, its mechanical properties is not appropriate for a bone substitiues. Therefore, it is used to improve the mechanical properties of polymer matrix composite scaffolds. In the present work chitosan as a polymeric matrix was employed to fabricate hydroxyapatite- chitosan biocomposite scaffolds. Sol-Gel method was employed to synthesize hydroxyapatite nano particles. Porous scaffolds were fabricated via freeze-drying by introducing two different cross linkers, Glutaraldehyde and Sodium Tripolyphosphate. Mechanical (compressive strength), biocampability and...