GPR investigations for the study and the restoration of the rose window of Troia Cathedral (southern Italy)

The development of cracks and distortions caused by past seismic events compromised the integrity of the rose window of Troia Cathedral, one of the most precious Romanesque monuments in southern Italy. Ground-penetrating radar (GPR) using high-frequency antennae (mainly 1500 MHz) was selected from among various non-destructive testing methods for its high-resolution imaging to scan the internal structure of the various architectural elements of the wheel window: the decimetre-diameter columns constituting the rays, the ring decorated with intersecting arched ribwork and the surrounding circular ashlar curb. GPR was employed in the classical continuous reflection mode, moving the antennae manually along the architectural elements and paying exceptional care in the acquisition and processing stages to avoid positioning errors. Indeed, the challenging aspects of this case study were the geometrical complexity and small dimensions of the structural elements, causing many logistic/coupling problems. In spite of this, through proper interpretation techniques, based on signal analysis (presence of reflections and diffractions, velocity and attenuation variations) and correlation with features detected by visual inspection of the external surfaces, the GPR survey provided useful information on the internal structure of the rose window, detecting fractures and the boundaries of previously restored parts and locating hidden metallic components connecting the architectural elements. Information on the internal structure and spatial distribution of metallic junctions was essential for gaining insight into building techniques in order to discriminate between restoration strategies which may require either total or partial dismantling of the rose window. GPR results provided crucial evidence in favour of one of the (conflicting) hypotheses about the original building techniques, leading to the selection of partial dismantling as the most suitable restoration strategy. Analysis of measurements revealed the potential of GPR in the field of cultural heritage restoration, even in those cases characterized by complex geometry, structural brittleness and logistic difficulties, such as that discussed in this paper

Transport Processes in Porous Media by Self-Potential Method

A controlled diffusion/infiltration column experimental activity was carried out with the aim of monitoring the leakage of a salty water plume by time-lapse self-potential (SP) measurements. In particular, three tracer tests with different NaCl concentrations (6.00, 1.00, and 0.25 g L−1) were performed and all the measured SP signals showed a sharp reduction corresponding to the arrival of saline front with negative electrical potential values (−78.99±3.24 mV, −54.52±2.28 mV, and −24.12±1.21 mV) which decrease with increasing volume of tracer introduced into the column. Then, measured self-potential values were converted into salt concentration ones by the Planck-Henderson equation and sand diffusion (D) and longitudinal dispersivity (αL) values were estimated by modelling the transport equations in the COMSOL Multiphysics environment. Finally, the results show that measured and estimated NaCl concentrations are well correlated

Using the ERT method in tectonically active areas: hints from Southern Apennine (Italy)

Abstract. Electrical Resistivity Tomography (ERT) method has been used to study two tectonically active areas of southern Apennine (Caggiano Faults and Ufita Basin). The main aim of this job was to study the structural setting of the investigated areas, i.e. the geometry of the basins at depth, the location of active faults at surface, and their geometrical characterization. The comparison between ERT and trench/drilling data allowed us to evaluate the efficacy of the ERT method in studying active faults and the structural setting of seismogenic areas. In the Timpa del Vento intermontane basin, high resolution ERT across the Caggiano Fault scarps, with different arrays, electrode spacing (from 1 to 10 m) and penetration depth (from about 5 to 40 m) was carried out. The obtained resistivity models allowed us to locate the fault planes along the hillslope and to gather information at depth, as later confirmed by paleoseismological trenches excavated across the fault trace. In the Ufita River Valley a 3560-m-long ERT was carried out across the basin, joining 11 roll-along multi-channel acquisition system with an electrode spacing of 20 m and reaching an investigation depth of about 170 m. The ERT allowed us to reconstruct the geometry and thickness of the Quaternary deposits filling the Ufita Valley. Our reconstruction of the depositional setting is in agreement with an interpretative geological section based on borehole data

Deep geophysical investigation in urban area: Ferrara city example

No abstract available

Arpi. Formes et modes de vie d’une cité italiote (IVe-IIe siècle av. n.è.)

Le texte de ces Chroniques présente la troisième et dernière étape préliminaire du programme de recherches sur Arpi : formes et modes de vie d’une cité italiote, qui a débuté en 2014 et vise à produire une synthèse sur les formes de l’habitat d’époque hellénistique. La double particularité du projet se reflète dans la composition de cette contribution : il prend appui, d’une part, sur l’étude topographique, stratigraphique et matérielle, des données de fouilles anciennes conduites sous la responsabilité de la Surintendance entre le début de la seconde guerre mondiale et la fin des années 1990, d’autre part sur la mise à jour des découvertes dans une base géoréférencée, sur une enquête d’archéologie des paysages, avec une approche archéomorphologique, géomorphologique et géophysique, et sur des prospections pédestres. La recontextualisation qui en résulte n’est possible que grâce à la complémentarité des expériences et des compétences réunies par la Surintendance des Pouilles, puis de Foggia, du Centre Jean Bérard et de l’Université de Salerne. Elle a été conduite à plusieurs échelles, de la maison au territoire, pour mieux définir les contraintes, les ressources et l’évolution du paysage au sein duquel s’est développé ce phénomène urbain de très grande envergure et encore difficile à cerner sur l’ensemble de l’espace limité par l’agger

Psychophysical assessment of olfactory and gustatory function in post-mild COVID-19 patients: A matched case-control study with two-year follow-up

Background: The aim of this study was to psychophysically evaluate the prevalence of smell and taste dysfunction two years after mildly symptomatic SARS-CoV-2 infection compared to that observed at one-year follow-up and while considering the background of chemosensory dysfunction in the no-COVID-19 population. Method: This is a prospective case-control study 93 patients with PCR-positive SARS-CoV-2 infection and 93 matched controls. Self-reported olfactory and gustatory dysfunction was assessed by Sino-nasal-Outcome-Test-22, item "Sense of smell or taste". Psychophysical ortho- and retronasal olfactory function and gustatory performance were estimated using the extended Sniffin' Sticks test battery, 20 powdered tasteless aromas, and taste strips test, respectively. Nasal trigeminal sensitivity was assessed by sniffing a 70% solution of acetic acid. Results: The two psychophysical assessments of chemosensory function took place after a median of 409 days (range: 366-461) and 765 days (range: 739-800) from the first SARS-CoV-2 positive swab, respectively. At two-year follow-up, cases exhibited a decrease in the prevalence of olfactory (27.9%% vs 42.0%; absolute difference, -14.0%; 95% CI, -21.8% to -2.6%; p = 0.016) and gustatory dysfunction (14.0% vs 25.8%; absolute difference, -11.8%; 95% CI, -24.2% to 0.6%; p = 0.098). Subjects with prior COVID-19 were more likely than controls to have an olfactory (27.9% vs 10.8 %; absolute difference, 17.2%; 95% CI, 5.2% to 28.8%) but not gustatory dysfunction (14.0% vs 9.7%; absolute difference, 4.3%; 95% CI, -5.8% to 14.4% p = 0.496) still two years after the infection. Overall, 3.2% of cases were still anosmic two-year after the infection. Conclusions: While a proportion of subjects recovered from long-lasting smell/taste dysfunction more than one year after COVID-19, cases still exhibited a significant excess of olfactory dysfunction two years after SARS-CoV-2 infection when compared to matched controls

Groundwater seepage is a key driver of theater-headed valley formation in limestone

Groundwater seepage leads to the formation of theater-headed valleys (THVs) in unconsolidated sediments. In bedrock, the role of groundwater in THV development remains disputed. Here, we integrate field and remote-sensing observations from Gnejna Valley (Maltese Islands) with numerical modeling to demonstrate that groundwater seepage can be the main driver of THV formation in jointed limestone overlying clays. The inferred erosion mechanisms entail (1) widening of joints and fractures by fluid pressure and dissolution and (2) creeping of an underlying clay layer, which lead to slope failure at the valley head and its upslope retreat. The latter is slower than the removal of the talus by creep and sliding on the valley bed. The location and width of THVs are controlled by the location of the master fault and the extent of the damage zone, respectively. The variability of seepage across the fault zone determines the shape of the valley head, with an exponential decrease in seepage away from the fault giving rise to a theater-shaped head that best matches that of Gnejna Valley. Our model may explain the formation of THVs by groundwater in jointed, strong-over-weak chemical sedimentary lithologies, particularly in arid terrestrial settings