Local seismic response studies in the north-western portion of the August 24th, 2016 Mw 6.0 earthquake affected area. The case of Visso village (Central Apennines).

In this work, we investigate the possible causes of the differential damaging observed in Visso village (Central Apennines, about 28 km north from the August 24th, 2016 Mw 6.0 earthquake epicenter). Following insights from the available geological cartography at 1:10.000 scale, a preliminary geophysical survey has been performed in the damaged area in order to constrain geometries and extent of the subsoil lithotypes. Then, these results have been used to retrieve a Vs profile close to the most heavily damaged buildings. This latter has been used as input for a numerical analysis aimed at deriving the motion at the ground level in the study area. In particular, a linear equivalent simulation has been performed by means of EERA code and the waveform has been obtained convolving the time history recorded during the August 24th, 2016 mainshock at Spoleto Monteluco (SPM) site. Our preliminary results indicate a possible correlation of damaging to the thickness and shape of the geological units. Nevertheless, further analyses are necessary to highlight any 2D basin and / non- linear soil behaviour effects in order to compare them to the intrinsic buildings vulnerability, according to the EMS98 guidelines

Poly-Dispersed Eulerian-Lagrangian Particle Tracking for In-Flight Icing Applications

The objective of this work is to present a three-dimensional Euler-Euler finite volume poly-dispersed (multi-bin) droplet tracker for in-flight icing purposes, with an additional Lagrangian re-injection step. This step has been added to increase the accuracy of the collection efficiency prediction in multi-element 2D and 3D cases where splashed and rebounding droplets re-impinge on aft surfaces, particularly in SLD conditions. Results show local increases in accuracy of up to 4% in a 3D single element case and up to 100% on flaps in 2D multi-element airfoil cases. The Lagrangian re-impingement correction improves significantly when using multi-bin, while also being more efficient than the standard approaches. Lastly, a simple bin to bin initialization strategy allows for up to 65% less computational time in the Eulerian droplet tracking step when running multi-bin simulations

Touch Versus Tech: When Technology Functions as a Barrier or a Benefit to Service Encounters

Interpersonal exchanges between customers and frontline service employees increasingly involve the use of technology, such as point-of-sale terminals, tablets, and kiosks. The present research draws on role and script theories to demonstrate that customer reactions to technology-infused service exchanges depend on the presence of employee rapport. When rapport is present during the exchange, the use of technology functions as an interpersonal barrier preventing the customer from responding in kind to employee rapport-building efforts, thereby decreasing service encounter evaluations. However, during service encounters in which employees are not engaging in rapport building, technology functions as an interpersonal barrier, enabling customers to retreat from the relatively unpleasant service interaction, thereby increasing service encounter evaluations. Two analyses using J.D. Power Guest Satisfaction Index data support the barrier and beneficial effects of technology use during service encounters with and without rapport, respectively. A follow-up experiment replicates this data pattern and identifies psychological discomfort as a key process that governs the effect. For managers, the results demonstrate the inherent incompatibility of initiatives designed to encourage employee–customer rapport with those that introduce technology into frontline service exchanges

Star formation history in the SMC: the case of NGC602

Deep HST/ACS photometry of the young cluster NGC 602, located in the remote low density "wing" of the Small Magellanic Cloud, reveals numerous pre-main sequence stars as well as young stars on the main sequence. The resolved stellar content thus provides a basis for studying the star formation history into recent times and constraining several stellar population properties, such as the present day mass function, the initial mass function and the binary fraction. To better characterize the pre-main sequence population, we present a new set of model stellar evolutionary tracks for this evolutionary phase with metallicity appropriate for the Small Magellanic Cloud (Z = 0.004). We use a stellar population synthesis code, which takes into account a full range of stellar evolution phases to derive our best estimate for the star formation history in the region by comparing observed and synthetic color-magnitude diagrams. The derived present day mass function for NGC 602 is consistent with that resulting from the synthetic diagrams. The star formation rate in the region has increased with time on a scale of tens of Myr, reaching $0.3-0.7 \times 10^{-3} M_\odot yr^{-1}$ in the last 2.5 Myr, comparable to what is found in Galactic OB associations. Star formation is most complete in the main cluster but continues at moderate levels in the gas-rich periphery of the nebula.Comment: 24 pages. Accepted for publication in A

Past and present star formation in the SMC: NGC 346 and its neighborhood

In the quest of understanding how star formation occurs and propagates in the low metallicity environment of the Small Magellanic Cloud (SMC), we acquired deep F555W (~V), and F814W (~I) HST/ACS images of the young and massive star forming region NGC 346. These images and their photometric analysis provide us with a snapshot of the star formation history of the region. We find evidence for star formation extending from ~10 Gyr in the past until ~150 Myr in the field of the SMC. The youngest stellar population (~3 +/- 1 Myr) is associated with the NGC 346 cluster. It includes a rich component of low mass pre-main sequence stars mainly concentrated in a number of sub-clusters, spatially co- located with CO clumps previously detected by Rubio et al. (2000). Within our analysis uncertainties, these sub-clusters appear coeval with each other. The most massive stars appear concentrated in the central sub-clusters, indicating possible mass segregation. A number of embedded clusters are also observed. This finding, combined with the overall wealth of dust and gas, could imply that star formation is still active. An intermediate age star cluster, BS90, formed ~4.3 +/-0.1 Gyr ago, is also present in the region. Thus, this region of the SMC has supported star formation with varying levels of intensity over much of the cosmic time.Comment: 38 pages, 13 figures, 3 tables; AJ accepte

Physical stratigraphy and geotechnical properties controlling the local seismic response in explosive volcanic settings: the Stracciacappa maar (central Italy)

Nowadays, policies addressed to prevention and mitigation of seismic risk need a consolidated methodology finalised to the assessment of local seismic response in explosive volcanic settings. The quantitative reconstruction of the subsoil model provides a key instrument to understand how the geometry and the internal architecture of outcropping and buried geological units have influence on the propagation of seismic waves. On this regard, we present a multidisciplinary approach in the test area of the Stracciacappa maar (Sabatini Volcanic District, central Italy), with the aim to reconstruct its physical stratigraphy and to discuss how subsoil heterogeneities control the 1D and 2D local seismic response in such a volcanic setting. We first introduce a new multidisciplinary dataset, including geological (fieldwork and log from a 45-m-thick continuous coring borehole), geophysical (electrical resistivity tomographies, single station noise measurements, and 2D passive seismic arrays), and geotechnical (simple shear tests performed on undisturbed samples) approaches. Then, we reconstruct the subsoil model for the Stracciacappa maar in terms of vertical setting and distribution of its mechanical lithotypes, which we investigate for 1D and 2D finite element site response analyses through the application of two different seismic scenarios: a volcanic event and a tectonic event. The numerical modelling documents a significant ground motion amplification (in the 1–1.5 Hz range) revealed for both seismic scenarios, with a maximum within the centre of the maar. The ground motion amplification is related to both 1D and 2D phenomena including lithological heterogeneity within the upper part of the maar section and interaction of direct S-waves with Rayleigh waves generated at edges of the most superficial lithotypes. Finally, we use these insights to associate the expected distribution of ground motion amplification with the physical stratigraphy of an explosive volcanic setting, with insights for seismic microzonation studies and local seismic response assessment in populated environments