Integrated geophysical investigation to detect buried structures: examples in the south-eastern part of Rome and its surroundings (Latium, central Italy)

Nell’ambito dell’engineering geology, il problema delle cavità antropiche che interessano centri abitati è particolarmente sentito, infatti, stando a modelli geologici recentemente sviluppati, esse possono migrare verso la superfice mettendo così a repentaglio la presenza di edifici, strade e l’incolumità degli stessi abitanti. Inoltre, i metodi d’investigazione diretti (quali sondaggi geognostici e indagini dirette del reticolo caveale) risultano essere piuttosto costosi e necessitano di numerose persone oltre di una certa quantità di tempo per essere realizzate. Al contrario i metodi indiretti (geofisici), oggetto del presente lavoro, consentono di indagare cavità di dimensioni anche ridotte in maniera estensiva oltre che generalmente rapida. Ciò premesso, nell’ambito del presente Dottorato, sono stati usati diversi metodi geofisici di near surface, integrandoli fra loro, allo scopo di caratterizzare le cavità presenti in due diversi test sites in ambito urbano ed extraurbano. La prima area test, indagata con il metodo GPR e il metodo ERT, è quella del Parco della Caffarella, in cui si ha una conoscenza solamente parziale di un esteso reticolo caveale scavato nelle pozzolane rosse dal quale si estraevano, in epoca etrusca e romana, materiali per l’edilizia. L’area indagata ha dimensioni 48 m x 30 m e la zona di sovrapposizione fra il metodo ERT e il GPR risulta essere di 48m x 14 m. Più in dettaglio, sono state eseguiti 14 profili ERT (modello Syscal Junior-Iris Instrument),aventi lunghezza 47 m con i 48 elettrodi posti ogni metro. L’array scelto è stato il doppio-dipolo poiché assicura una buona risoluzione sia in termini di variazioni verticali che orizzontali delle resistività, come ampiamente noto in letteratura. L’area in oggetto è stata indagata con il GPR (Modello SIR-3000, GSSI) usando dapprima un’antenna bistatica, ad offset costante, ad alta frequenza (400 MHz) e successivamente un’antenna monostatica a bassa frequenza (70 MHz). Nel primo caso i profili sono stati acquisiti con un’interdistanza pari a 0.5 m mentre nel secondo con un’interdistanza pari a 1 m. I dati sono stati elaborati con software specifici per estrarre delle sezioni tempo-profondità (time-slice) dell’area indagata con i dati GPR e delle sezione profondità bidimensionali (depth-slice) con i dati ERT. La seconda area è sita nel territorio di Magliano Sabina-Loc. Madonna del Giglio (Rieti), nella quale, da numerose fonti archeologiche è nota la presenza di strutture funerarie a fossa (VII-VI sec. a.C.), parzialmente collassate. L’area di dimensioni 80 m x 30 m è stata indagata, dapprima con il GPR (Modello SIR-3000,GSSI) usando un’antenna bistatica ad offset costante ad alta frequenza (400 MHz) acquisendo i profili ogni 0.5 m e successivamente con il magnetometro differenziale fluxgate (FM256-Geoscan Research), suddividendo l’area in 7 quadrati di 10 m di lato, con i profili paralleli acquisiti ogni metro e le misure lungo il profilo ogni 0.5 m. La zona di sovrapposizione fra i due metodi è stata di 70 m x 10 m. Anche in questo caso dai dati GPR sono state ricavate le time-slices mentre i dati magnetici sono stati elaborati con la crosscorrelazione normalizzata bidimesionale allo scopo di far emergere le anomalie da un contesto geologico altrimenti piuttosto rumoroso. Dopo le suddette operazioni, per entrambi i siti sono stati testati diversi metodi di integrazione sia di tipo qualitativo (Contour map overlay, RGB Colour Composite) che di tipo quantitativo (data sum, data product, binary representation) oltre di tipo statistico (Principal Component Analysis, K-mean Cluster analysis, Bayesian Maximum Entropy). I risultati, incoraggianti, mostrano come alcuni dei metodi summenzionati siano fin da ora spendibili in un contesto applicativo, mentre altri si trovino ad un livello di ricerca

Ellipsoidal relaxations of the stable set problem:theory and algorithms

A new exact approach to the stable set problem is presented, which attempts to avoid the pitfalls of existing approaches based on linear and semidefinite programming. The method begins by constructing an ellipsoid that contains the stable set polytope and has the property that the upper bound obtained by optimising over it is equal to the Lovasz theta number. This ellipsoid can then be used to construct useful convex relaxations of the stable set problem, which can be embedded within a branch-and-bound framework. Extensive computational results are given, which indicate the potential of the approach

Evolución de la comunidad de moluscos del lago Sabaudia: causas antropogénicas

The evolution of the molluscan biota in Sabaudia Lake (Italy, central Tyrrhenian Sea) in the last century is hereby traced on the basis of bibliography, museum type materials, and field samplings carried out from April 2009 to September 2011. Biological assessments revealed clearly distinct phases, elucidating the definitive shift of this human-induced coastal lake from a freshwater to a marine-influenced lagoon ecosystem. Records of marine subfossil taxa suggest that previous accommodations to these environmental features have already occurred in the past, in agreement with historical evidence. Faunal and ecological insights are offered for its current malacofauna, and special emphasis is given to alien species. Within this framework, Mytilodonta Coen, 1936, Mytilodonta paulae Coen, 1936 and Rissoa paulae Coen in Brunelli and Cannicci, 1940 are also considered new synonyms of Mytilaster Monterosato, 1884, Mytilaster marioni (Locard, 1889) and Rissoa membranacea (J. Adams, 1800). Finally, human-driven environmental changes and cumulative anthropogenic pressures proved to be the whole driver of the constitution of the human-induced malacofauna studied, casting doubts on the correct use of the definition of "native fauna"

Strengthening Chvátal-Gomory cuts for the stable set problem

The stable set problem is a well-known NP-hard combinatorial optimization problem. As well as being hard to solve (or even approximate) in theory, it is often hard to solve in practice. The main difficulty is that upper bounds based on linear programming (LP) tend to be weak, whereas upper bounds based on semidefinite programming (SDP) take a long time to compute. We propose a new method to strengthen the LP-based upper bounds. The key idea is to take violated Chvátal-Gomory cuts and then strengthen their right-hand sides. Although the strengthening problem is itself NP-hard, it can be solved reasonably quickly in practice. As a result, the overall procedure proves to be capable of yielding competitive upper bounds in reasonable computing times

Optimizing Nozzle Travel Time in Proton Therapy

Proton therapy is a cancer therapy that is more expensive than classical radiotherapy but that is considered the gold standard in several situations. Since there is also a limited amount of delivering facilities for this techniques, it is fundamental to increase the number of treated patients over time. The objective of this work is to offer an insight on the problem of the optimization of the part of the delivery time of a treatment plan that relates to the movements of the system. We denote it as the Nozzle Travel Time Problem (NTTP), in analogy with the Leaf Travel Time Problem (LTTP) in classical radiotherapy. In particular this work: (i) describes a mathematical model for the delivery system and formalize the optimization problem for finding the optimal sequence of movements of the system (nozzle and bed) that satisfies the covering of the prescribed irradiation directions; (ii) provides an optimization pipeline that solves the problem for instances with an amount of irradiation directions much greater than those usually employed in the clinical practice; (iii) reports preliminary results about the effects of employing two different resolution strategies within the aforementioned pipeline, that rely on an exact Traveling Salesman Problem (TSP) solver, Concorde, and an efficient Vehicle Routing Problem (VRP) heuristic, VROOM

ccd photometry of the m 67 cluster in the vilnius photometric system

The Vilnius photometric system, consisting of seven passbands at 345, 374, 405, 466, 516, 544 and 656 nm makes it possible to determine spectral classes (or temperatures), absolute magnitudes (or surface gravities), metallicities and peculiarity types for stars of all spectral types in the presence of interstellar reddening (Straizys 1977, 1992a, b). This makes the system very useful for the determination of the physical parameters of stars which are too faint to be studied by spectroscopic methods. The system is especially effective when used with CCD detectors which combine a wide field, high sensitivity and high photometric accuracy

Towards a permanent deep sea observatory,: the GEOSTAR European Experiment.

GEOSTAR is the prototype of the first European long-term, multidisciplinary deep sea observatory for continuous monitoring of geophysical, geochemical and oceanographic parameters. Geostar is the example of a strong synergy between science and tecnology addressed to the development of new technological solutions for the observatory realisation and management. The GEOSTAR system is described outlining the enhancements introduced during five years of project activity. An example of data retrieved from the observatory being the deep sea mission running is also given.Published111-1202.5. Laboratorio per lo sviluppo di sistemi di rilevamento sottomarinireserve

GEOSTAR, an observatory for deep sea geophysical and oceanographic researches: characteristics, first scientific mission and future activity

GEOSTAR (GEophysical and Oceanographic STation for Abyssal Research) is a project funded by in the 4th Framework Programme of the European Commission, with the aim of developing an innovative deep sea benthic observatory capable of carrying out long-term (up to 1 year) scientific observations at abyssal depths. The configuration of the observatory, conceived to be a node of monitoring networks, is made up of two main subsystems: the Bottom Station, which in addition to the acquisition and power systems and all the sensors also hosts the communications systems; and the Mobile Docker, a dedicated tool for surface-assisted deployment and recovery. At present the Bottom Station is equipped with a triaxial broad-band seismometer, two magnetometers (fluxgate and scalar), CTD, transmissometer, ADCP, but it can easily host other sensors for different experiments. The first phase of the project, started in November 1995, was concluded with the demonstration mission in Adriatic Sea at shallow water depth (42 m) in August - September 1998. Some preliminary results of this first scientific experiment are presented and discussed. The second phase, started in 1999, will end with a long-term deep sea scientific mission, scheduled during 2000 for 6-8 months at 3400 m.w.d. in the southern Tyrrhenian bathyal plain.Published491-4973A. Ambiente MarinoN/A or not JCRrestricte

The new Checklist of the Italian Fauna: marine Mollusca.

The mollusc fauna of the Mediterranean Sea is still considered as the best-known marine mollusc fauna in the world. The previous modern checklists of marine Mollusca were produced by joint teams of amateurs and professionals. During the last years the Italian Society of Malacology (Società Italiana di Malacologia – S.I.M.) maintained an updated version of the Mediterranean checklist, that served as the backbone for the development of the new Italian checklist. According to the current version (updated on April 1st, 2021), 1,777 recognised species of marine molluscs are present in the Italian Economic Exclusive Zone, including also the Tyrrhenian coasts of Corsica and the continental shelf of the Maltese archipelago. The new checklist shows an increase of 17% of the species reported in the 1995 Checklist. This is largely (yet not solely) due to the new wave of studies based on Integrative Taxonomy approaches. A total of 135 species (7.6%) are strictly endemic to the Italian waters; 44 species (2.5%) are alien and correspond to the 28% of the Mediterranean alien marine molluscs. All eight extant molluscan classes are represented. The families represented in the Italian fauna are 307, an increase of 14.6% from the first checklist, partly due to new records and partly to new phylogenetic systematics. Compared with the whole Mediterranean malacofauna, the Italian component represents 71% in species and 61% in families, which makes it a very remarkable part of the Mediterranean fauna

Mission results from the first GEOSTAR observatory (Adriatic Sea, 1998)

We assess the first mission of the GEOSTAR (GEophysical and Oceanographic STation for Abyssal Research) deep-sea multidisciplinary observatory for its technical capacity, performance and quality of recorded data. The functioning of the system was verified by analyzing oceanographic, seismological and geomagnetic measurements. Despite the mission’s short duration (21 days), its data demonstrated the observatory’s technological reliability and scientific value. After analyzing the oceanographic data, we found two different regimes of seawater circulation and a sharp and deepening pycnocline, linked to a down-welling phenomenon. The reliability of the magnetic and seismological measurements was evaluated by comparison with those made using on-land sensors. Such comparison of magnetic signals recorded by permanent land geomagnetic stations and GEOSTAR during a “quiet” day and one with a magnetic storm confirmed the correct functioning of the sensor and allowed us to estimate the seafloor observatory’s orientation. The magnitudes of regional seismic events recorded by our GEOSTAR seismometer agreed with those computed from land stations. GEOSTAR has thus proven itself reliable for integrating other deep-sea observation systems, such as modular observatories, arrays, and instrumented submarine cablesPublished361-373ope