Sub-Doppler resonances in the back-scattered light from random porous media infused with Rb vapor

We report on the observation of sub-Doppler resonances on the back-scattered light from a random porous glass medium with rubidium vapor filling its interstices. The sub-Doppler spectral lines are the consequence of saturated absorption where the incident laser beam saturates the atomic medium and the back-scattered light probes it. Some specificities of the observed spectra reflect the transient atomic evolution under confinement inside the pores. Simplicity, robustness and potential miniaturization are appealing features of this system as a spectroscopic reference.Comment: 6 pages, 4 figure

Magnetometer suitable for Earth field measurement based on transient atomic response

We describe the development of a simple atomic magnetometer using $^{87}$Rb vapor suitable for Earth magnetic field monitoring. The magnetometer is based on time-domain determination of the transient precession frequency of the atomic alignment around the measured field. A sensitivity of 1.5 nT/$\sqrt{Hz}$ is demonstrated on the measurement of the Earth magnetic field in the laboratory. We discuss the different parameters determining the magnetometer precision and accuracy and predict a sensitivity of 30 pT/$\sqrt{Hz}$Comment: 6 pages, 5 figure

Comparative fragility methods for seismic assessment of masonry buildings located in Muccia (Italy)

The current paper focuses on a sector of the historic centre of Muccia, in the district of Macerata (Italy), affected by the seismic sequence that involved Central Italy in 2016. The main goal is comparison, in terms of fragility curves, among two vulnerability assessment methodologies (empirical and mechanical). The study area has been structurally and typologically identified according to the Building Typology Matrix (BTM). Physical vulnerability analysis of the urban-sector was performed through application of an index-based method, specifically for masonry building aggregates. An isolated masonry building, damaged after the seismic sequences, has been selected as a case study. For the assessed building, empirical fragility curves are presented according to Guagenti & Petrini’s correlation law. Furthermore, a numerical model has been set up by using the macro-element approach, which has allowed to perform non-linear static analyses. Mechanical properties of masonry were defined according to the New Technical Codes for Constructions (NTC18), assuming a limited knowledge level (LC1). Refined mechanical fragility functions have been derived and compared to the empirical ones. Analysis results have shown that the empirical method tends to overestimate by 5% and 10% the expected damage for slight and moderate thresholds. For PGA values greater than 0,3 g the damage levels decreased by 30% and 20%, with reference to the near collapse and collapse conditions, respectively

The Curious Case of Metonymic Verbs: A Distributional Characterization

Logical metonymy combines an event-selecting verb with an entity-denoting noun (e.g.,The writer began the novel), triggering a covert event interpretation (e.g., reading, writing). Experimental investigations of logical metonymy must assume a binary distinction between metonymic (i.e. event-selecting) verbs and non-metonymic verbs to establish a control condition. However, this binary distinction (whether a verb is metonymic or not) is mostly made on intuitive grounds, which introduces a potential confounding factor. We describe a corpus-based approach which characterizes verbs in terms of their behavior at the syntax-semantics interface. The model assesses the extent to which transitive verbs prefer event-denoting objects over entity-denoting objects. We then test this “eventhood” measure on psycholinguistic datasets, showing that it can distinguish not only metonymic from non-metonymic verbs, but that it can also capture more fine-grained distinctions among different classes of metonymic verbs, putting such distinctions into a new graded perspective

Fitting, Not Clashing! A Distributional Semantic Model of Logical Metonymy

Logical metonymy interpretation (e.g. begin the book ->writing) has received wide attention in linguistics. Experimental results have shown higher processing costs for metonymic conditions compared with non-metonymic ones ( read the book). According to a widely held interpretation, it is the type clash between the event-selecting verb and the entity-denoting object (begin the book) that triggers coercion mechanisms and leads to additional processing effort. We propose an alternative explanation and argue that the extra processing effort is an effect of thematic fit. This is a more economical hypothesis that does not need to postulate a separate type clash mechanism: entity-denoting objects simply have a low fit as objects of event-selecting verbs. We test linguistic datasets from psycholinguistic experiments and find that a structured distributional model of thematic fit, which does not encode any explicit argument type information, is able to replicate all significant experimental findings. This result provides evidence for a graded account of coercion phenomena in which thematic fit accounts for both the trigger of the coercion and the retrieval of the covert even

Numerical model upgrading of a historical masonry building damaged during the 2016 Italian earthquakes: the case study of the Podestà palace in Montelupone (Italy)

In October 2016, two major earthquakes occurred in Marche region in the Centre of Italy, causing widespread damage. The epicentre of the second one struck Norcia, Visso and Accumoli and a lot of damages to cultural heritage were done in the cities of Tolentino, San Severino, Camerino, Matelica, Macerata and Montelupone, where are located the Podesta` Palace and the Civic Tower investigated in this paper. The main aim of this research is the determination of modal properties of these historical masonry constructions using experimental and numerical studies. The experimental analysis was based on ambient vibration survey, while numerical analysis was based on finite element analysis with solid elements. The results of the experimental study were used to tune the numerical model of the structure. As the most doubtful parameters, the modulus of elasticity of the masonry and the interaction among structural parts were adjusted to achieve the experimental results with numerical model by simple operations. Obtaining good consistency between the experimental and numerical analyses, the study revealed the actual dynamic properties of the damaged palace

On infinite-volume mixing

In the context of the long-standing issue of mixing in infinite ergodic theory, we introduce the idea of mixing for observables possessing an infinite-volume average. The idea is borrowed from statistical mechanics and appears to be relevant, at least for extended systems with a direct physical interpretation. We discuss the pros and cons of a few mathematical definitions that can be devised, testing them on a prototypical class of infinite measure-preserving dynamical systems, namely, the random walks.Comment: 34 pages, final version accepted by Communications in Mathematical Physics (some changes in Sect. 3 -- Prop. 3.1 in previous version was partially incorrect