Our purpose in this study was to establish a selection standard for anti-scatter grids for a direct conversion flat-panel detector (FPD) system. As indices for grid evaluation, we calculated the selectivity, Bucky factor, and the signal-to-noise ratio improvement factor (SIF) by measuring rates of scatter transmission, primary transmission, and total transmission (based on the digitally display...

The effects of elastic constants mismatch on the interaction between a propagating crack and single or multiple inclusions in brittle matrix materials are investigated using numerical simulations. The simulations employ a quasi-static crack-growth prediction tool based upon the symmetric-Galerkin boundary element method (SGBEM) for multiregions, a modified quarter-point crack-tip element, the d...

This article utilizes the average stress method to obtain the stress intensity factor of rotating solid and hollow disks/cylinders containing a radial crack‎. ‎It is assumed that the cracks are located radially at center‎, ‎internal or external radius of the geometry‎. ‎Results are shown for both of the plane stress and plane strain assumptions and are validated against the known data introduce...

To determine the effects of steel factor (SIF) on the number and distribution of phenotypically defined hematopoietic stem cells in vivo, mice were treated with continuous s.c. infusions of SIF for up to 7 days. The bone marrow demonstrated a transient 5-fold increase in the number of c-kit-positive lineage-negative/low cells with no change in cellularity. The radioprotective capacity of bone m...

Title of Document: IMPROVED PROBABILISTIC LIFE ESTIMATION IN ENGINEERING STRUCTURES: MODELING MULTI-SITE FATIGUE CRACKING Abdallah (Moh’d AR.) (Sh. M.) Al Tamimi, PhD, 2014 Directed By: Minta Martin Professor of Engineering, Mohammad Modarres, Reliability engineering The purpose of this paper is to investigate the effect of fatigue, in the presence of neighboring cracks, and to integrate that i...