Ricerc@Sapienza

We present a study of wave overtopping of barriers. The phenomenon of the wave overtopping over emerged structures is reproduced both numerically and experimentally. The numerical simulations are carried out by a numerical scheme for three-dimensional free-surface flows, which is based on the solution of the Navier-Stokes equations in a novel integral form on a time-dependent coordinate system. In the adopted numerical scheme, a novel wet-dry technique, based on the exact solution of the Riemann problem over the dry bed, is proposed.

In this work, a second-order phase approximation is introduced to provide an improved analytical model of the signal received in forward scatter radar systems. A typical configuration with a rectangular metallic object illuminated while crossing the baseline, in far-or near-field conditions, is considered. An improved second-order model is compared with a simplified one already proposed by the authors and based on a paraxial approximation. A phase error analysis is carried out to investigate benefits and limitations of the second-order modeling.

o explore the promising therapeutic applications of short nanosecond electric pulses, in vitro and in vivo experiments are highly required. In this paper, an exposure system based on monopole patch antenna is reported to perform in vivo experiments on newborn mice with both monopolar and bipolar nanosecond signals. Analytical design and numerical simulations of the antenna in air were carried out as well as experimental characterizations in term of scattering parameter (S11) and spatial electric field distribution.

Since the introduction of functional magnetic resonance imaging (fMRI), several computational approaches have been developed to examine the effect of the morphology and arrangement of blood vessels on the blood oxygenation-level dependent (BOLD) signal in the brain. In the present work, we implemented the original Ogawa's model using a numerical simulation based on the finite element method (FEM) instead of the analytical models.

Hyperthermia is a therapeutic technique used to enhance the efficacy of radiotherapy and chemotherapy in the treatment of oncological pathologies, by way of a temperature increase of 41–43°C in the target region. To validate hyperthermia devices, as well as the numerical codes used to simulate hyperthermia treatments, simple phantoms are used. This article considers the influence of phantoms’ geometry, dimensions, and considered organs, on the electromagnetic power absorption.