[Article] Dynamics of spiral waves in a cardiac electromechanical model with a local electrical inhomogeneity Original Citation: Mesin L. (2012). Dynamics of spiral waves in a cardiac electromechanical model with a local electrical inhomogeneity. Porto, the institutional repository of the Politecnico di Torino, is provided by the University Library and the IT-Services. The aim is to enable open...

The analysis of the gas in a single expirate has long been used to estimate the degree of ventilation-perfusion (Va/Q) inequality in the lung. To further validate this estimate, we examined three measures of Va/Q inhomogeneity calculated from a single full exhalation in nine anesthetized mongrel dogs under control conditions and after exposure to aerosolized methacholine. These measurements wer...

Diffusion tensor imaging (DTI) and advanced related methods such as diffusion spectrum and kurtosis imaging are limited by low signal-to-noise ratio (SNR) at conventional field strengths. DTI at 7 T can provide increased SNR; however, B0 and B1 inhomogeneity and shorter T2⁎ still pose formidable challenges. The purpose of this study was to quantify and compare SNR at 7 and 3 T for different par...

a mathematical model is presented in the present study to control‎ ‎the light propagation in an inhomogeneous media‎. ‎the method is ‎based on the identification of the optimal materials distribution‎ ‎in the media such that the trajectories of light rays follow the‎ ‎desired path‎. ‎the problem is formulated as a distributed parameter ‎identification problem and it is solved by a numerical met...

Introduction B1 inhomogeneity in a human body increases as the strength of static magnetic field increases and the RF wavelength becomes smaller. Recently, various RF control methods have been developed to reduce B1 inhomogeneity. For example, some methods involve devices such as dielectric pads [1,2] or coupling coils [3,4], or techniques such as B1 shimming [5,6]. However, B1 inhomogeneity st...

Current experimental investigation deals with the effects of asymmetrical rolling parameters on the inhomogeneity, microstructure, mechanical, and geometrical properties of rolled brass wire. Toward this end, a roll machine with three different roll radii ratios was set up. The asymmetrical conditions are arranged using three different sets of rolls with different diameters that result into dif...

Recent developments in nanostructured products draw considerable attention to ultrafine grained materials. These materials are normally manufactured by different severe plastic deformation (SPD) methods. In the present study, analytical models and finite element method (FEM) are used to calculate strain imposed to a specimen that was deformed by equal channel angular pressing (ECAP). In additio...