University of Sannio

About: University of Sannio is a education organization based out in Benevento, Italy. It is known for research contribution in the topics: Gravitational wave & LIGO. The organization has 1278 authors who have published 6125 publications receiving 167577 citations. The organization is also known as: Università degli Studi del Sannio & Universita degli Studi del Sannio.

Experimental tests on full-scale RC unretrofitted frame and retrofitted with buckling-restrained braces

Abstract: SUMMARY The results of experimental tests carried out on reinforced concrete (RC) full-scale 2-storey 2-bays framed buildings are presented. The unretrofitted frame was designed for gravity loads only and without seismic details; such frame was assumed as a benchmark system in this study. A similar RC frame was retrofitted with buckling-restrained braces (BRBs). The earthquake structural performance of both prototypes was investigated experimentally using displacement-controlled pushover static and cyclic lateral loads. Modal response properties of the prototypes were also determined before and after the occurrence of structural damage. The results of the dynamic response analyses were utilized to assess the existing design rules for the estimation of the elastic and inelastic period of vibrations. Similarly, the values of equivalent damping were compared with code-base relationships. It was found that the existing formulations need major revisions when they are used to predict the structural response of as-built RC framed buildings. The equivalent damping ratio ξeq was augmented by more than 50% when the BRBs was employed as bracing system. For the retrofitted frame, the overstrength Ω and the ductility µ are 1.6 and 4.1, respectively; the estimated R-factor is 6.5. The use of BRBs is thus a viable means to enhance efficiently the lateral stiffness and strength, the energy absorption and dissipation capacity of the existing RC substandard frame buildings. The foundation systems and the existing members of the superstructure are generally not overstressed as the seismic demand imposed on them can be controlled by the axial stiffness and the yielding force of the BRBs. Copyright © 2011 John Wiley & Sons, Ltd.

A Learning Management System Including Laboratory Experiments on Measurement Instrumentation

Abstract: This paper presents a comprehensive approach to distance learning for electric and electronic measurement courses. The proposed approach integrates a traditional Learning Management System (LMS) with the remote access to real instrumentation located in different laboratories, without requiring specific software components on the client side. The advantages of using LMSs in distance learning of measurement-related topics are summarized describing some LMS characteristics. Then, the remote laboratory system relying on virtual instruments (VIs) developed in LabVIEW and its integration with an off-the-shelf LMS are described in a project financed by the Italian Ministry of Education and University

Tunneling of obliquely incident waves through PT -symmetric epsilon-near-zero bilayers

Abstract: We show that obliquely incident, transversely magnetic-polarized plane waves can be totally transmitted (with zero reflection) through epsilon-near-zero (ENZ) bilayers characterized by balanced loss and gain with parity-time ($\mathcal{PT}$) symmetry. This tunneling phenomenon is mediated by the excitation of a surface wave localized at the interface separating the loss and gain regions. We determine the parameter configurations for which the phenomenon may occur and, in particular, the relationship between the incidence direction and the electrical thickness. We show that, below a critical threshold of gain and loss, there always exists a tunneling angle which, for moderately thick (wavelength-sized) structures, approaches a critical value dictated by the surface-wave phase-matching condition. We also investigate the unidirectional character of the tunneling phenomenon, as well as the possible onset of spontaneous symmetry breaking, typical of $\mathcal{PT}$-symmetric systems. Our results constitute an interesting example of a $\mathcal{PT}$-symmetry-induced tunneling phenomenon, and may open up intriguing venues in the applications of ENZ materials featuring loss and gain.