Development of a multi-phase dynamic ray-tracing code

We here propose a method for rapid, high-frequency seismogram generation that makes use of an algorithm to automatically generate an exhau- stive set of seismic phases that produce an appreciable amplitude on the sei- smogram. The method uses a hierarchical order of rays and seismic phases generation, taking into account some existence constraints for a ray-path and some physical constraints. To compute synthetic seismograms, the COMRAD code (from the Italian: “COdice Multifase per il RAy-tracing Dinamico”) uses as its core a dynamic ray-tracing code. To validate the code, we have computed in a layered medium synthetic seismograms using both COMRAD and a code which computes the complete wavefield by the discrete wavenumber method. The seismograms are compared according to a time-frequency misfit criteria based on the continuous wavelet transform of the signals. The comparison shows that the ray-theory seismogram is enough complete and moreover, the time for the computing of the synthetics using the COMRAD code (truncating the ray series at the 10th generation) is 3-4-fold less than that needed for the Axitra code (to a frequency of 25 Hz)

1-D P-velocity Models of Mt. Vesuvius Volcano from the Inversion of TomoVes96 First Arrival Time Data

—We applied a revised version of the 1-D τ–p inversion method to first P-arrival times from the active seismic experiment performed at Mt. Vesuvius (southern Italy) in 1996 (TomoVes96 Project). The main objective of this work is to obtain 1-D velocity models of Mt. Somma-Vesuvius volcano complex and surrounding area. Moreover we show that combining the 1-D information we provide a reliable 2-D initial model for perturbative tomographic inversions. Seismic and geological surveys suggest the presence of a refractor associated with the contrast between carbonate basement and volcanic/alluvial sediments; synthetic simulations, using a realistic topography and carbonate top morphology, allowed us to study the effect of topography on the retrieved velocity models and to check that the 1-D τ–p method can also approximately retrieve the refractor depth and velocity contrast. We analysed data from 14 on-land shots recorded at stations deployed along the in-profile direction. We grouped the obtained models in three subsets according to the geology of the sampling area: Models for carbonate outcrop area, models for the Campanian Plain surrounding the volcano edifice and models for Mt. Somma-Vesuvius volcano complex. The found 1-D P-velocity models show important vertical and lateral variations. Very low velocities (1.5–2.5 km/s) are observed in the upper 200–500 m thick shallow layer. At greater depths (3 km is the maximum investigated depth) P velocities increase to values in the range of 4–6 km/s which are related to the presence of the carbonatic basement. Finally we interpolated the 1-D models to demonstrate an example of misfit for a 2-D interpolated model whose residuals are confined in a narrow band around zero

Confronto di differenti tecniche per la valutazione dell'amplificazione di sito nella città di Benevento

In the tex

Colorimetric paper-based device for hazardous compounds detection in air and water: A proof of concept

In the last decades, the increase in global industrialization and the consequent technological progress have damaged the quality of the environment. As a consequence, the high levels of hazardous compounds such as metals and gases released in the atmosphere and water, have raised several concerns about the health of living organisms. Today, many analytical techniques are available with the aim to detect pollutant chemical species. However, a lot of them are not affordable due to the expensive instrumentations, time-consuming processes and high reagents volumes. Last but not least, their use is exclusive to trained operators. Contrarily, colorimetric sensing devices, including paper-based devices, are easy to use, providing results in a short time, without particular specializations to interpret the results. In addition, the colorimetric response is suitable for fast detection, especially in resource-limited environments or underdeveloped countries. Among different chemical species, transition and heavy metals such as iron Fe(II) and copper Cu(II) as well as volatile compounds, such as ammonia (NH3) and acetaldehyde (C2 H4 O) are widespread mainly in industrialized geographical areas. In this work, we developed a colorimetric paper-based analytical device (PAD) to detect different contaminants, including Fe2+ and Cu2+ ions in water, and NH3 and C2 H4 O in air at low concentrations. This study is a “proof of concept” of a new paper sensor in which the intensity of the colorimetric response is proportional to the concentration of a detected pollutant species. The sensor model could be further implemented in other technologies, such as drones, individual protection devices or wearable apparatus to monitor the exposure to toxic species in both indoor and outdoor environments

Post-mortem diagnosis of intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare (<1%), typically aggressive extranodal variant of mature non-Hodgkin B-cell lymphoma. IVLBCL is characterized by malignant lymphoid cells lodged within blood vessels, particularly capillary channels. Herein, we present a case of a 50-year-old man with a history of myeloradiculitis (∼1 year) and paraparesis requiring hospitalization. During the course of his hospital stay, computed tomography (CT), magnetic resonance imaging, CT-positron emission tomography, and biopsy failed to establish a diagnosis. The patient died 2 months later from bilateral pneumonia. Postmortem examination was undertaken to determine the cause of death. Histologic sections of the patient’s brain, heart, lung, and liver showed aggregates of highly atypical cells bearing enlarged, pleomorphic, and hyperchromatic nuclei. Strong intravascular positivity for CD45 and CD20 markers indicated the cells were of B-cell origin, supporting a diagnosis of IVLBCL

Fluorescent Silver Nanoclusters Embedded in Hydrogel Matrix and Its Potential Use in Environmental Monitoring

The optical absorption and fluorescence of silver nanoclusters (AgNCs) are widely exploited in many different application fields such as sensors, bio-imaging, drug delivery, etc. In the sensor field, optical devices are highly versatile thanks to their ease of fabrication and low costs and, therefore, are optimal candidates to replace expensive apparatuses commonly used. In this study, we synthesized AgNCs in aqueous phase by photochemical synthesis using poly methacrylic acid (PMAA) as a stabilizer. Colloidal water solutions of these NCs showed a very good sensitivity to Pb(II) ions, and in order to fabricate a solid-state sensor, we introduced them in a hydrogel material formed by poly(ethylene glycol) diacrylate with a molecular weight of 700 g/mol (PEGDA700). The systems were characterized using absorption and fluorescence spectroscopy and transmission electron microscopy (TEM). Finally, the sensitivity to Pb(II) ions has been tested with the aim to use these systems as solid-state optical sensors for water quality

Fluorescent silver nanoclusters embedded in hydrogel matrix and its potential use in environmental monitoring

The optical absorption and fluorescence of silver nanoclusters (AgNCs) are widely exploited in many different application fields such as sensors, bio-imaging, drug delivery, etc. In the sensor field, optical devices are highly versatile thanks to their ease of fabrication and low costs and, therefore, are optimal candidates to replace expensive apparatuses commonly used. In this study, we synthesized AgNCs in aqueous phase by photochemical synthesis using poly methacrylic acid (PMAA) as a stabilizer. Colloidal water solutions of these NCs showed a very good sensitivity to Pb(II) ions, and in order to fabricate a solid-state sensor, we introduced them in a hydrogel material formed by poly(ethylene glycol) diacrylate with a molecular weight of 700 g/mol (PEGDA(700)). The systems were characterized using absorption and fluorescence spectroscopy and transmission electron microscopy (TEM). Finally, the sensitivity to Pb(II) ions has been tested with the aim to use these systems as solid-state optical sensors for water quality

Polypeptidic Micelles Stabilized with Sodium Alginate Enhance the Activity of Encapsulated Bedaquiline

The coating of polypeptidic micelles with sodium alginate is described as a strategy to improve the stability of micelles for drug delivery. Bedaquiline, approved in 2012 for the treatment of multidrug resistant tuberculosis, has been used as an example of hydrophobic drug to study the loading efficiency, the release of the encapsulated drug in different media, and the in vitro antimicrobial activity of the system. Alginate coating prevents the burst release of the drug from micelles upon dilution and leads to a sustained release in all tested media. In view of possible oral administration, the alginate coated micelles show better stability in gastric and intestinal simulated media. Notably, the encapsulated bedaquiline shows increased in vitro activity against Mycobacterium tuberculosis compared to free bedaquiline

Three-dimensional tomography and rock properties of the Larderello-Travale

In a geothermal area, a detailed knowledge of the three-dimensional velocity structures aids the managementof the field and the further development of the geothermal source. Here,we present a high-resolution study of the three-dimensional S-wave velocity structures from microearthquake travel times for the Larderello-Travale geothermal field, Italy.We have also deduced the Vp/Vs and Vp ×Vs parameters for this area toemphasize the deep variations in the physical rock properties due to fluid content and porosity. Furthermore, effective porousmedium modelling has been performed for site-relevant lithologies, to improve our interpretation of the results in terms of rock physics signatures. This has allowed us to estimate the variation range of the seismological parameters investigated, as well as their sensitivity for suitable rock under specific physical conditions. LowVp/Vs anomalies, arising froma lower Vp compared to Vs, dominate the geothermal field of Larderello-Travale. These have been interpreted as due to steam-bearing formations. On the contrary, analysis of Vp ×Vs images provides information on the relative changes in rock porosity at depth. Comparison of tomographic section images with previously interpreted seismic lines suggests that the reflective ‘K-horizon’ delineates a transition between zones that have different porosities or crack gatherings. The ‘K-horizon’ also lies on low Vp/Vs anomalies, which suggests a steam saturation zone, despite the reduced porosity at this depth