Spirals abound in excitable media. Various PDE models have been suggested in order to explain and predict some of the incarnations of these dynamic entities. In two landmark papers, Barkley [1, 2] noticed that a general family of these were caused by the Euclidean symmetry (inherent in the media) of the models. But the experimental universe is un-perfectly Euclidean, by necessity. The heart, fo...

background paranasal sinus ct has high sensitivity and specificity for sinusitis. however, this modality is costly and involves greater radiation exposure than plain radiographs. objectives we tried to compare 10-cut limited ct scan and standard ct scan in the diagnosis of sinusitis. materials and methods we conducted a cross sectional case series from august to december 2010 on 150 patients wi...

In this paper, a numerical scheme for a generalized planar Ginzburg-Landau energy in a circular geometry is studied. A spectral-Galerkin method is utilized, and a stability analysis and an error estimate for the scheme are presented. It is shown that the scheme is unconditionally stable. We present numerical simulation results that have been obtained by using the scheme with various sets of bou...

conclusions there was no statistically significant difference in the parotid absorbed dose between spiral tomography and a panoramic radiograph (p value = 0.18). the overall results of this study were similar to other studies. results for the tube side parotid, the average absorbed doses in spiral tomography of the anterior and posterior parts of the maxilla and mandible, with the 2 mm slice th...

In recent decades, one of the challenges in sheet metal forming was production of two-step bending surfaces without mechanical tools and external force or by a combination of heat source and mechanical tools. Forming with a heat source such as laser beam has the potential for forming arbitrary 3D shapes such as two-step bending surfaces. In this paper a novel method for laser forming of complic...

statement of the problem in order to replace lost tooth of patients, we use dental implants which are common. therefore, accurate measuring of bone height and width before placing implants is necessary. the aim of this study is evaluating the accuracy of linear and spiral tomography in careful determination of implant site sizes in comparison with gold standard (cbct). material and methods this...

The valley-polarized quantum anomalous Hall (VQAH) state, which forwards a strategy for combining valleytronics and spintronics with nontrivial topology, attracts intensive interest in condensed-matter physics. So far, the explored VQAH states have still been limited to magnetic systems. Here, using low-energy effective model Floquet theorem, we propose different mechanism realize state nonmagn...

We report the results of self-gravitating simulations of spiral galaxies, modeled by stellar and gaseous components, developed to investigate in particular the role of dissipation in the evolution of galaxy disks. The gas disk is simulated by the Beam-Scheme method, where it is considered as a self-gravitating fluid. The results suggest that the gravitational coupling between the stars and gas ...