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Controlling contaminant plumes in groundwater using pump and treat or hydraulic and physical barriers is a common practice to contain and reduce solute contaminants in remediation activities. Recent evolution in engineering techniques also allowed to extend the number of solutions that can be designed and set in practice. As such, the decision-making process assumes great importance in leading the selection of the best suitable technology for a certain case study. This process has to take into account technical, environmental and socioeconomic factors. This paper presents the results of a research project aimed at defining a multi-criteria procedure analysis to support the decision-making process in the barrier technology selection, taking into account technical, economic, social and environmental factors. A multi-criteria analysis methodology has been defined to provide a quantitative tool to guide the selection of the best suitable technology concerning a specific case. The methodology was applied to a real case, selected from many case studies based on data availability and quality, in order to verify the effectiveness of the procedure in evaluating the alternative selections and to highlight the differences between the results of the multi-criteria analysis and the real engineers choices. A sensitivity analysis was performed to analyze the influence of each criterion on the final result of the study. With this paper we aim to start a discussion to deepen the decision making process, in order to develop methodologies allowing to chose the best solution without subjective evaluations.

In recent years, the contamination of the underground resources from landfill leachates is recognised as a serious socio-economic and environmental problem in many countries. In fact, the existing not adequately controlled and abandoned sites, constitute a serious sanitary and environmental problems. The choice of the waste disposal site must necessarily arise from a rigorous study based on the joint assessment of the environmental hazard of the same plant and the hydrogeological characteristics and the degree of intrinsic vulnerability to pollution of the aquifers. In the present paper an integrated system for the assessment of the environmental risk from solid waste landfills is proposed. The integrated analysis of the intrinsic vulnerability of the aquifer system and the estimate of the intrinsic potential hazard caused by the landfill expressed in terms of danger index allow to evaluate the suitability of the sites to host a landfill and to define the reclamation priority and monitoring system for the existing landfills. As concerns new landfills, the proposed methodology could also support a better construction strategy and the protection of the surrounding environment. Finally, this methodological approach was applied in landfills located in different geological and hydrogeological contexts.

The paper presents and discusses results from the integration of various methods of geophysical prospection on the plateau between the Via Appia and the Via Ardeatina on the ancient suburb of Rome. The use of large-scale magnetometry, georadar and electromagnetic survey in an area of particularly dense archaeological remains is a highly effective methodology for revealing important information on previously unknown archaeological features. Of particular interest in this case is the comparison between geophysical data and the results of previous excavations, and newly-targeted test investigations that suggest the survival of the documented but previously undiscovered basilica of Pope Damasus as well as unknown catacomb tunnels at San Callisto and elsewhere on the plateau.

A spectral-domain method, for the solution of the two-dimensional electromagnetic plane-wave scattering by a finite set of perfectly-conducting or dielectric cylinders buried in a dielectric half-space, has been developed. The scattered field is represented in terms of a superposition of cylindrical waves, and use is made of the plane-wave spectrum to take into account the reflection and transmission of such waves by the interface. The problem is solved for both the near- and the far-field regions, for TM and TE polarizations. In this work we briefly resume the theoretical basis of our approach. For configurations in which more obstacles are buried in the ground, and they are near to one another, we give details about the convergence rate of our method, and about the properties of our algorithms for the integration of cylindrical functions. With our technique it is possible to simulate two-dimensional buried obstacles of general shape, by means of a suitable set of circular-section cylinders: in this paper we show preliminary results of simulations carried out using arrays of same-radius circular cylinders, and of different-radius circular cylinders.

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.

The paper describes the findings of a geo-electric study conducted at the archaeological site of Torraccia di Chiusi (Siena Province) with the use of soil resistivity modelling. In collaboration with the Département d’Archéologie et Histoire de l’Art (Université catholique de Louvain, Belgium) and the Centro di GeoTecnologie (Università degli Studi di Siena), a new, non-invasive instrument, named the OhmMapper, was used for the first time in an archaeological context to provide geophysical sections of the terrain. The aim of the study was to evaluate the nature and distribution of the buried anthropogenic structures and to properly locate them on the map without the necessity of excavating. The site, located in the valley of the Foci river, has been described as a long lasting settlement (III to VII centuries AD, although ceramics dating to the II century BC have been uncovered). The OhmMapper is a capacitively coupled resistivity meter that measures the electrical properties of rocks and soil without ground stakes used in traditional resistivity surveys. A simple coaxial-cable array with transmitter and receiver sections is pulled along the ground either by a single person or attached to an all-terrain vehicle. The dipole-dipole configuration enables the instrument to immediately pick up the horizontal variations in resistivity, thereby enabling the user to identify structures such as walls or cavities. With the OhmMapper, nine sections were made around the perimeter of the area already excavated to collect data on the presence, depth, and dimensions of anthropogenic structures. The results from the sections were refined and placed on a map using an ArcGIS platform. The interpretation of the nine sections resulted in a new hypothesis on the buried anthropogenic structures and a new model of the natural landscape that existed at the site prior to its construction.

In the recent years more and more countries around the world have been concerned with space debris detection and monitoring. In Italy, although satellites and debris have been definitely, though not intentionally, detected by astronomers in the last decades, dedicated observations have never been performed before April 2002. In this month the Group of Astrodynamics of the University of Rome “La Sapienza” (GAUSS) started an optical survey of the geostationary ring from the Campo Catino Astronomical Observatory. This observatory, owned by the “Associazione Astronomica Frusinate” (Frosinone Astronomical Society), is one of the best amateur astronomers’ facilities in Italy: his dome hosts an 80 cm aperture Ritchey-Chrétien telescope, a 25 cm Baker-Schmidt and a 15 cm refractor, while a 40 cm Ritchey-Chrétien is going to be operated in another dome; two CCD sensors are available for such telescopes. For this first GEO campaign, the 25 cm Baker-Schmidt device was chosen, in order to have a wide field of view: the telescope was coupled with an AP-8 10241024 CCD, resulting in a 1°, 50’ FOV. The first nights of observation were dedicated to a survey of the GEO ring: about 90 degrees of right ascension were spanned, collecting several hundreds images and detecting about 100 objects; as the CCD read-out time is about 35 seconds, a relatively long exposure time (20 seconds) was selected, to improve the ratio of exposure time to gap time between frames. The telescope was pointed in a star-tracking mode, so the Earth satellites are easily detected as stripes on a dot-shaped background of stars; hence, two points of the track (lead and trailing edges) per image are generally identified in terms of topocentric right ascension and declination. Moreover, the observed star field is kept constant along some hours of observation, letting the GEO ring cross such field. The data processing, presently managed off-line, is now being carried out, in order to identify the objects and determine their orbits. Of course other observations will be performed in the next months. In the paper the campaign status is described in detail and the results are presented.

In this paper we describe four large volume, ash- and accretionary lapilli-rich, phreatomagmatic compound ignimbrite units, mafic in composition, from Colli Albani volcano, south of Rome. The four units, that form the ‘Pisolitic Tuffs’ succession, are separated by paleosols and represent the earliest explosive large volume eruptive episodes from the Quaternary Alban Hills volcano. The occurrence of large volume phreatomagmatic–phreatoplinian eruptions implies the availability of large quantities of water interacting with the rising magma. The paleogeography of the area below the volcano has been reconstructed by the analysis of stratigraphic data from more than a thousand bore-holes distributed around the volcano that allowed to identify NW-trending and NE-trending paleotopographic lows that underlie the central area of the volcano and interpreted as extensional tectonic basins. These lows are filled with Lower to Middle Pleistocene, pre-volcanic lacustrine and fluvial deposits and suggest that at least the central part of the Colli Albani volcanic area hosted a large lake or lagoon. The absence of sedimentary xenoliths in the Pisolitic Tuffs and the low vesicularity of scoria and shards suggest that water interacted with a poorly fragmented magma at very shallow level, triggering the large explosivity of the eruptions. We suggest that water interacting with magma was mostly surficial water related to the presence of the lagoon or lake. In this environment, it is likely that vents were subaqueous allowing a continuous access of water to the conduit. Considering that the minimum calculated volume of products for the Pisolitic Tuffs succession is >37 km3 and each eruption unit averages approximately around minimum volume of 10 km3, we suggest that each eruption was related to a caldera collapse, which would have allowed the persistence of a Taupo-like lake in the central area and of phreatoplinian activity. After the last phreatomagmatic eruption, however, the fragmentation style of large volume ignimbrites from Colli Albani became magmatic, suggesting the extinction of the lake after that date. Each of the four units show a basal phreatoplinian fallout level, overlain by a complex association of low aspect ratio surge deposits and ignimbrites. Phreatomagmatic pyroclastic flow deposits are found at distances of more than 40 km from the central area of the volcano, and show important facies variation according to the paleotopography. To the west of the volcano, pyroclastic flows reached the Tyrrhenian coast and emplaced mostly stratified facies on a flat topography, interpreted to reflect both the spreading of pyroclastic flows on an unconfined topography and their interaction with lacustrine and lagoon areas. By contrast, to the east of the volcano, where pyroclastic flows were confined within paleovalleys, the main facies is thick and massive.