The church of St. Saturnino in Cagliari, Sardinia, reading the levels of history through the use of digital survey and the petrophysical study of materials

The most ancient church in Cagliari is dedicated to Saint Saturno (commonly named Saint Saturnino), the first indications about this church came from the sixth century, but the building arrived to our time is only a part of the original one and it rises over the ruins of previous structures, inside a a walled area with the presence of a Palaeo-Christian necropolis. The original Greek cross plan with a transept and a semi-spherical dome; has seen meaningful transformations in time, with the partial destruction of large parts of the building. All the four arms had a nave and two aisles, but the current church consists only of the dome-covered area and of the eastern arm, with a nave and two aisles. The whole church shows very interesting parts coming from previous architectures of the Roman age, a rich catalog of rich materials and details. In summer 2013, a collaboration between the Departments of Chemical and Geological Sciences from Cagliari and the one of Architecture from Florence brought to the realization of a detailed study about this ancient church. The whole building and its surrounding area were surveyed with the following methods: photography, 3D Laser Scanner for the whole interior and exterior parts, 3D photogrammetry of a selected set of stone surface samples, direct sampling of representative rocks for geochemical and petrophysical analysis. All data were then treated and analyzed to deepen the knowledge about the most meaningful aspects of different construction techniques and use of materials, provenance of raw materials, stone and structure alterations. As the result, a base was created to read common behaviors, design choices, recursive constructive solutions, and the “models” guiding the ancient intentions. This contribution will present the progress state of this research and its results

Contamination of the Environmental Matrices in Agricultural Areas Produced by Industrial Discharges: The Case Study of the Land of the City of Statte (Taranto, Southern Italy)

The diffusion of pollutants in the atmosphere, agricultural soil, irrigation water, crops and food chain can produce potential environmental health risk. The aims of this study are the environmental risk assessment for the aquifers and the estimation of pollutants concentration in the forage for evaluating the risk for human health. The risk analysis was applied in the rural territory of Statte (Taranto, Italy) using an innovative methodology based on the integration of models for estimation of pollutant leaching in the groundwater and for the evaluation of bio-transfer of pollutant in the plant. The model results are in accordance with the experimental values and therefore the proposed methodology allows the evaluation and management of environmental health risks in agricultural areas interested by pollution phenomena generated by industrial plants

Instantons and Killing spinors

We investigate instantons on manifolds with Killing spinors and their cones. Examples of manifolds with Killing spinors include nearly Kaehler 6-manifolds, nearly parallel G_2-manifolds in dimension 7, Sasaki-Einstein manifolds, and 3-Sasakian manifolds. We construct a connection on the tangent bundle over these manifolds which solves the instanton equation, and also show that the instanton equation implies the Yang-Mills equation, despite the presence of torsion. We then construct instantons on the cones over these manifolds, and lift them to solutions of heterotic supergravity. Amongst our solutions are new instantons on even-dimensional Euclidean spaces, as well as the well-known BPST, quaternionic and octonionic instantons.Comment: 40 pages, 2 figures v2: author email addresses and affiliations adde

Physical mechanical consolidation and protection of Miocenic limestone used on Mediterranean historical monuments: the case study of Pietra Cantone (southern Sardinia, Italy)

The present work aims to study the consolidating and protective chemical treatments of the Pietra Cantone, a Miocenic (lower Tortonian) limestone widely used in important monuments and historical buildings of Cagliari (southern Sardinia, Italy). Similar limestones of the same geological period have also been used in several important monuments of Mediterranean area, i.e., Malta and Gozo Islands, Matera (central Basilicata, Italy), Lecce (southern Puglia, Italy) and Balearic Islands (Spain). The Pietra Cantone limestone shows problems of chemical–physical decay, due to their petrophysical and compositional char- acteristics: high porosity (on average 28–36 vol%), low cemented muddy-carbonate matrix, presence of phyllosil- icates and sindepositional sea salts (\3%). So, after placed in the monument, this stone is easily alterable by weath- ering chemical processes (e.g., carbonate dissolution and sulfation) and also by cyclic mechanisms of crystalliza- tion/solubilization of salts and hydration/dehydration of hygroscopic phases of the clay component. To define the mineralogical-petrographic features (composition, texture) of limestone, the clay and salt crystalline phases, the optical microscope in polarized light and diffraction anal- ysis were used. To define the petrophysical characteristics (i.e., shape and size distribution of porosity, surface area(SBET), matrix microstructures, rock composition) and interactions of chemical treatments with rock, SEM–EDS analysis and N2 porosimetry with BET and BJH methods were used. To evaluate the efficacy of Na/K-silicates, ethyl silicate consolidants and protective nano-molecular silane monomer water repellent, the mechanical strengths (uni- axial compressive strength, point load and flexural resis- tance), water/helium open porosity, water absorption and vapour permeability data determined before and after the chemical treatments of the Pietra Cantone samples from monument were compared

The Wide-field Spectroscopic Telescope (WST) Science White Paper

The Wide-field Spectroscopic Telescope (WST) is proposed as a new facility dedicated to the efficient delivery of spectroscopic surveys. This white paper summarises the initial concept as well as the corresponding science cases. WST will feature simultaneous operation of a large field-of-view (3 sq. degree), a high multiplex (20,000) multi-object spectrograph (MOS) and a giant 3x3 sq. arcmin integral field spectrograph (IFS). In scientific capability these requirements place WST far ahead of existing and planned facilities. Given the current investment in deep imaging surveys and noting the diagnostic power of spectroscopy, WST will fill a crucial gap in astronomical capability and work synergistically with future ground and space-based facilities. This white paper shows that WST can address outstanding scientific questions in the areas of cosmology; galaxy assembly, evolution, and enrichment, including our own Milky Way; origin of stars and planets; time domain and multi-messenger astrophysics. WST's uniquely rich dataset will deliver unforeseen discoveries in many of these areas. The WST Science Team (already including more than 500 scientists worldwide) is open to the all astronomical community. To register in the WST Science Team please visit https://www.wstelescope.com/for-scientists/participat

The health risk of the agricultural products grown in potentially contaminated sites: proposal of an environmental – health risk analysis

The rural territory is often interested by polluting phenomena determined by agricultural activities with high pesticides use and/or by industrial plants or illegal dumps. The risk for the human health coming from the polluters presence in the environmental can be quantitatively evaluated by the environmental health risk analysis defined by the Legislative Decree n. 152/2006. The technical-normative procedure of risk analysis not consider the specificity of the soils designed to agricultural use and the possible agricultural products contaminations. This work aims at filling this technical-normative lack by identifying and applying a suitable methodology for the evaluation of the health risk caused by the ingestion of agricultural products grown in contaminated soils. This work shows the results of the risk analysis applied to a contaminated area in southern Italy by an innovative methodology based on scientifically consolidated and widely accepted relations. In addition, some concentration limits of organic polluters in agricultural soils are proposed