Laser Scanner 3D per lo studio e la catalogazione dell’archeologia medievale: la chiesa di Santa Croce in Bergamo

The improvement of new active optical sensors has revolutionized the methods for documenting cultural heritage. The conservation and appreciation of our cultural legacy re¬quire an extensive documentation both in terms of shape, color and geometry as well as the more traditional art-historical features. The incessant development of scientific research today provides new possibilities and tools which are essential to know and use in a responsible and scientific way. In the field of archaeology, the automatic 3D survey is now recognized as an added value compared to traditional practices and the active contribution that this technology can provide to the interpretative phase, cataloguing and promotion of archaeological assets, even through the web, is becoming increasingly clear. On the other hand, even considering the speed of the procedure and the accuracy of measurement, there have been calls for reflection on the role that laser scanning can play in the field of archaeology; this role needs to be clarified and consolidated by conducting new studies and experiments, such as the one presented here that concerns the Church of Santa Croce in Bergamo, a small octagonal Romanesque chapel built in the first half of the 11th century

Sulphur abundance determinations in star-forming regions-I: Ionization Correction Factor

In the present work we used a grid of photoionization models combined with stellar population synthesis models to derive reliable Ionization Correction Factors (ICFs) for the sulphur in star-forming regions. These models cover a large range of nebular parameters and yielding ionic abundances in consonance with those derived through optical and infrared observational data of star-forming regions. From our theoretical ICFs, we suggested an {\alpha} value of 3.27 in the classical Stasinska formulae. We compared the total sulphur abundance in the gas phase of a large sample of objects by using our Theoretical ICF and other approaches. In average, the differences between the determinations via the use of the different ICFs considered are similar to the uncertainties in the S/H estimations. Nevertheless, we noted that for some objects it could reach up to about 0.3 dex for the low metallicity regime. Despite of the large scatter of the points, we found a trend of S/O ratio to decrease with the metallicity, independently of the ICF used to compute the sulphur total abundance.Comment: Accepted for publication in MNRAS, 21 pages, 8 figures, 5 table

High velocity blue-shifted FeII absorption in the dwarf star-forming galaxy PHL293B: Evidence for a wind driven supershell?

X-shooter and ISIS WHT spectra of the starforming galaxy PHL 293B also known as A2228-00 and SDSS J223036.79-000636.9 are presented in this paper. We find broad (FWHM = 1000km/s) and very broad (FWZI = 4000km/s) components in the Balmer lines, narrow absorption components in the Balmer series blueshifted by 800km/s, previously undetected FeII multiplet (42) absorptions also blueshifted by 800km/s, IR CaII triplet stellar absorptions consistent with [Fe/H] < -2.0 and no broad components or blushifted absorptions in the HeI lines. Based on historical records, we found no optical variability at the 5 sigma level of 0.02 mag between 2005 and 2013 and no optical variability at the level of 0.1mag for the past 24 years. The lack of variability rules out transient phenomena like luminous blue variables or SN IIn as the origin of the blue shifted absorptions of HI and FeII. The evidence points to either a young and dense expanding supershell or a stationary cooling wind, in both cases driven by the young cluster wind.Comment: Accepted for publication in MNRAS; 15 pages, 10 figure

THE CHURCH OF SANT'ANDREA IN BERGAMO: AN INTEGRATED SURVEY FOR KNOWLEDGE AND CONSERVATION

Abstract. The church dedicated to Sant'Andrea (St. Andrew) in Porta Dipinta street in Bergamo city is a treasure that keep inside it a rich heritage of great historical and cultural value, both from the architectural and from the artistic point of view. Lacking of the façade (left unfinished), it is often neglected, despite being on the main road leading to the old town from Sant'Agostino Gate. The approach to an historical building like this requires a multi-disciplinary integration, in order to join the technical competence of engineering sciences to the sensitivity of human and fine arts sciences. For a better understanding of the structural performances of the building, historical research, measurement survey, material and decay condition study have to complement each other.</p

Interaction effects on galaxy pairs with Gemini/GMOS- II: Oxygen abundance gradients

In this paper we derived oxygen abundance gradients from HII regions located in eleven galaxies in eight systems of close pairs. Long-slit spectra in the range 4400-7300A were obtained with the Gemini Multi-Object Spec- trograph at Gemini South (GMOS). Spatial profiles of oxygen abundance in the gaseous phase along galaxy disks were obtained using calibrations based on strong emission-lines (N2 and O3N2). We found oxygen gradients signifi- cantly flatter for all the studied galaxies than those in typical isolated spiral galaxies. Four objects in our sample, AM1219A, AM1256B, AM 2030A and AM2030B, show a clear break in the oxygen abundance at galactocentric radius R/R25 between 0.2 and 0.5. For AM1219A and AM1256B we found negative slopes for the inner gradients, and for AM2030B we found a positive one. In all these three cases they show a flatter behaviour to the outskirts of the galaxies. For AM2030A, we found a positive-slope outer gradient while the inner one is almost compatible with a flat behaviour. A decrease of star forma- tion efficiency in the zone that corresponds to the oxygen abundance gradient break for AM1219A and AM2030B was found. For the former, a minimum in the estimated metallicities was found very close to the break zone that could be associated with a corotation radius. On the other hand, AM1256B and AM2030A, present a SFR maximum but not an extreme oxygen abundance value. All the four interacting systems that show oxygen gradient breakes the extreme SFR values are located very close to break zones. Hii regions lo- cated in close pairs of galaxies follow the same relation between the ionization parameter and the oxygen abundance as those regions in isolated galaxies.Comment: 30 pages, 14 figures, accepted MNRAS, (Figs. 1 and 2 are in low resolution

ESSAYS ON INEQUALITY, HOUSEHOLD DEBT AND FINANCIAL INSTABILITY

My Ph.D. thesis contributes to the growing literature on the link between inequality and economic crises, focusing in particular on the relationship between rising income disparities, household debt dynamics and the resulting financial instability. In the first paper, I review both the theoretical and the empirical literature on inequality, by paying particular attention to the way this topic has been treated over time by the economics research agenda. I show that the impact of growing income disparities on the macroeconomy has been ignored for a long period of time, particularly starting from the 80s. Only after the recent financial crisis, the issue of income and wealth distribution has come back on the top of the agenda of economists as well as policymakers. In the other two papers, I build two macroeconomic models that focus on the link between income inequality, household debt and economic crises. The first one is an Agent-Based (AB) macroeconomic model aimed at describing the key mechanisms through which rising inequality jeopardises economic stability in an economy with peer effects in consumption and equity extraction processes. I show that greater income disparities imply stronger expenditure cascades along the income distribution as well as asset (i.e. house) price appreciation. In the presence of home-equity based borrowing behaviour by households, private debt rises thus pushing aggregate demand upwards despite income stagnation over much of the distribution. However, debt-driven consumption endogenously triggers the accumulation of a larger amount of non-performing loans on banks\u2019 balance sheets which eventually lead to a credit crunch and an economic downturn. The second model, a joint work with Francesco Saraceno which I carried out during my visiting period at OFCE-SciencesPo in Paris, is a macroeconomic model with an Agent-Based household sector and a stock-flow consistent structure. The goal of this work is to analyse the impact of rising income inequality on the likelihood of a crisis under different institutional settings and degrees of financialisation. In particular, we reproduce a multitude of scenarios showing how financial and credit conditions interact with the impact of growing inequality on the performance of the economy and the accumulation of household debt. Our results show the relevance of the \u201cdegree\u201d of financialisation of an economy. In fact, when inequality grows, a Scyilla and Charybdis kind of dilemma seems to arise: on the one hand, economies with low credit availability experience a drop in aggregate de- mand and output; on the other hand, where credit constraints are relaxed and the willingness to lend is higher, greater financial instability emerges and a debt-driven boom and bust cycle. We also show that policy reactions play a key role: a real structural reform that tackles inequality, by means of a more progressive tax system, actually compensates for the rise in income disparities thereby stabilising the economy. Results also show that this is a much better solution compared to a stronger fiscal policy reaction, which, instead, has no significant impact on the performance of the economy

Optical and mid-infrared neon abundance determinations in star-forming regions

We employed observational spectroscopic data of star-forming regions compiled from the literature and photoionization models to analyse the neon ionic abundances obtained using both optical and mid-infrared emission-lines. Comparing Ne++/H+ ionic abundances from distinct methods, we found that, in average, the abundances obtained via IR emission-lines are higher than those obtained via optical lines by a factor of 4. Photoionization models with abundance variations along the radius of the hypothetical nebula provide a possible explanation for a large part of the difference between ionic abundances via optical and infrared emission-lines. Ionization Correction Factor (ICF) for the neon is obtained from direct determinations of ionic fractions using infrared emission-lines. A constant Ne/O ratio (logNe/O \approx -0.70) for a large range of metallicity, independently of the ICF used to compute the neon total abundance is derived.Comment: 17 pages, 14 figures, accepted by MNRA

Studies for the Conservation and Valorisation of the Archaeological Rock Heritage of Calascibetta in Sicily, Italy

Abstract. The rock settlement of Vallone Canalotto, which stands in the valleys surrounding the town of Calascibetta – about three kilometres north from Enna, Sicily, Italy – testify to a widespread population of the area from prehistoric times up to the Middle Ages, probably linked to the agricultural and pastoral exploitation of its fertile land. This valuable heritage, dug into very soft limestone banks, is now threatened by significant erosion and disruption phenomena, which, in the absence of adequate safeguarding and maintenance actions, will lead to a progressive loss of material and the consequent collapse of some portions, making the documentable traces more and more paltry. The archaeological complex demonstrates the continuity of the funerary use from the remotest ages to the early Christian era, as testified by the excavation of rupestrian columbaria. In the early medieval period, small rural communities used the hypogeal structures for residential and religious purposes. In the present work, integrated procedures have been put in place for the 3D documentation of these artefacts, whose effectiveness has already been tested by the same team in other Sicilian rock sites. The research aims at the knowledge and cataloguing of places, which are important for the Island's history but to date only marginally explored. It intends to stimulate and plan adequate conservation and enhancement activities. To improve the attendance of the sites, design proposals have been developed to guarantee greater accessibility to the archaeological areas and their understanding by visitors

INTEGRATED 3D SURVEY AND DIAGNOSTIC ANALYSIS FOR THE BUILDING ENGINEERING: THE FORMER KINDERGARTEN SAN FILIPPO NERI IN DALMINE

The paper aims to emphasise the positive contribution that the 3D laser scanning and digital photogrammetry survey, integrated with diagnostic analysis techniques, can make in the field of construction engineering. The case study of the former kindergarten San Filippo Neri in Dalmine intends to contribute to the development of methodologies and operational tools related to the knowledge and conservation of modern and contemporary heritage. After archival research aimed at retracing the building's technical-constructive evolution, the study was extended out through the metric and morphological survey of both its external walls and internal spaces, paying special attention to the analysis of the deformations of the large horizontal surfaces, such as floors and ceilings. Diagnostic investigations – thermographic and microclimatic – have completed the survey campaign, so allowed to read both the envelope and the substance of the building, and to identify the critical issues. This work adopts and shows the correct glide slope to succeed in an adaptive reuse project in which the design stage can result solely from the in-depth study of the building

Metallicity Determination in Seyfert 2 AGNs

Aims: To study calibrations of line ratios that can estimates metallicities of galaxies even in large redshift where the measurement of faint emission lines is not easy to obtain. Methods: We use the Cloudy Code to build a grid of photoionization models with lines ratios from the UV and, we compare with a sample of 77 object AGNs Seyfert 2. Results: We build semi-empirical calibrations between the metallicity of studied objects and the rest-frame intensity of the line ratios N V λ1240 / HeII λ1640, C43=log[(Civ λ1549 + CIII] λ1909) / HeII λ1640] and CIII] λ1909 / C IV λ1549.Fil: Monteiro, A. F.. Universidade Do Vale Do Paraíba; BrasilFil: Dors, O. L.. Universidade Do Vale Do Paraíba; BrasilFil: Cardaci, Monica Viviana. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Hägele, Guillermo Federico. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaII workshop on Chemical abundances in gaseous nebulae: open problems in nebular astrophysicsSao Jose dos CamposBrasilUniversidade do Vale do Paraíb