Rip current evidence by hydrodynamic simulations, bathymetric surveys and UAV observation

Abstract. The prediction of the formation, spacing and location of rip currents is a scientific challenge that can be achieved by means of different complementary methods. In this paper the analysis of numerical and experimental data, including RPAS (remotely piloted aircraft systems) observations, allowed us to detect the presence of rip currents and rip channels at the mouth of Sele River, in the Gulf of Salerno, southern Italy. The dataset used to analyze these phenomena consisted of two different bathymetric surveys, a detailed sediment analysis and a set of high-resolution wave numerical simulations, completed with Google EarthTM images and RPAS observations. The grain size trend analysis and the numerical simulations allowed us to identify the rip current occurrence, forced by topographically constrained channels incised on the seabed, which were compared with observations

Riflessione di onde regolari in presenza di opere a gettata

Il lavoro di tesi si propone l'obiettivo di indagare il fenomeno della riflessione ondosa di opere a gettata di massi con qualsivoglia livello di cresta e di fornire una metodologia per la stima del coefficiente di riflessione

A Probabilistic Prediction of beach nourishment evolution

A II level probabilistic analysis for predicting the lifetime of a beach nourishment project has been proposed. Considering that the new wider beach serves as shore protection by storms and to increase recreational benefits, it has been assumed that the beach reaches its failure state when its width becomes lower than a specified minimum. With reference to the one-dimensional equation of the beach planform evolution, the limit state function has been evaluated adopting an analytical formulation, which assumes curvilinear and parallel contours landward the beach nourishment project. In order to investigate the effects of the project’s geometry and of the fill material nature on the probability of failure, a sensitivity analysis has been performe

Reliability analysis of existing breakwaters

The relevant steps for reliability analysis are fwst described referring to a generic system and then applied to typical maritime structures. A picture of the existing codes that suggest target reliability level is supplied to compare reliability estimate with the target value. Reliability methods were applied to a typical rubble mound breakwater and to a typical vertical breakwater. The results have shown that reliability level of maritime structures is low if compared with the target values suggested by codes

An Electronic System for the Contactless Reading of ECG Signals

The aim of this work is the development of a contactless capacitive sensory system for the detection of (Electrocardiographic) ECG-like signals. The acquisition approach is based on a capacitive coupling with the patient body performed by electrodes integrated in a front-end circuit. The proposed system is able to detect changes in the electric charge related to the heart activity. Due to the target signal weakness and to the presence of other undesired signals, suitable amplification stages and analogue filters are required. Simulated results allowed us to evaluate the effectiveness of the approach, whereas experimental measurements, recorded without contact to the skin, have validated the practical effectiveness of the proposed architecture. The system operates with a supply voltage of ±9 V with an overall power consumption of about 10 mW. The analogue output of the electronic interface is connected to an ATmega328 microcontroller implementing the A/D conversion and the data acquisition. The collected data can be displayed on any multimedia support for real-time tracking applications