Suitable classification of mortars from ancient roman and renaissance frescoes using thermal analysis and chemometrics

Background Literature on mortars has mainly focused on the identification and characterization of their components in order to assign them to a specific historical period, after accurate classification. For this purpose, different analytical techniques have been proposed. Aim of the present study was to verify whether the combination of thermal analysis and chemometric methods could be used to obtain a fast but correct classification of ancient mortar samples of different ages (Roman era and Renaissance). Results Ancient Roman frescoes from Museo Nazionale Romano (Terme di Diocleziano, Rome, Italy) and Renaissance frescoes from Sistine Chapel and Old Vatican Rooms (Vatican City) were analyzed by thermogravimetry (TG) and differential thermal analysis (DTA). Principal Component analysis (PCA) on the main thermal data evidenced the presence of two clusters, ascribable to the two different ages. Inspection of the loadings allowed to interpret the observed differences in terms of the experimental variables. Conclusions PCA allowed differentiating the two kinds of mortars (Roman and Renaissance frescoes), and evidenced how the ancient Roman samples are richer in binder (calcium carbonate) and contain less filler (aggregate) than the Renaissance ones. It was also demonstrated how the coupling of thermoanalytical techniques and chemometric processing proves to be particularly advantageous when a rapid and correct differentiation and classification of cultural heritage samples of various kinds or ages has to be carried out

Torsion in strain-gradient plasticity: energetic scale effects

Abstract. We study elasto-plastic torsion in a thin wire within the framework of the strain-gradient plasticity theory elaborated by Gurtin and Anand in 2005. The theory in question envisages two material scales: an energetic length-scale, which takes into account the so-called “geometrically-necessary dislocations” through a dependence of the free energy on the Burgers tensor, and a dissipative length-scale. For the rate-independent case with null dissipative length-scale, we construct and characterize a special class of solutions to the evolution problem. With the aid of such characterization, we estimate the dependence on the energetic scale of the ratio between the torque and the twist. Our analysis confirms that the energetic scale is responsible for size-dependent strain-hardening, with thinner wires being stronger. We also detect, and quantify in terms of the energetic length-scale, both a critical twist, after which the wire becomes fully plastified, and two boundary layers near the external boundary of the wire and near the boundary of the plastified region, respectively. The research that led to the present paper was partially supported by a grant of the group GNFM of INdA

Carbonate factory of Pietra di Finale coastal wedge (Miocene): the unusual abundance of stylasterids (Cnidaria, Hydrozoa)

This work focuses on the carbonate factories constituting the Pietra di Finale Fm cropping out in the Ligurian Alps. This unit constituted a mixed carbonate-siliciclastic coastal wedge developed during the Middle Miocene. The carbonate factories characterizing the coastal wedge of the Pietra di Finale clearly differ from those of the coastal mixed systems and carbonate platforms developing during the Miocene elsewhere in the Mediterranean area. Here, in the Ligurian Alps, the euphotic carbonate factory does not show any evidence of seagrass meadows and coral bioconstructions. Zooxanthellate corals are present only as skeletal debris associated with abundant stylasterids. In the mesophotic and oligophotic zones, the typical oligophotic biota of red algae and larger benthic foraminifers are strongly reduced. The coastal wedge of the Pietra di Finale shows an unusual abundance of stylasterids, classically interpreted as deep-water biota. However, in this example, the absence of low-energy textures and other skeletal components suggest a shallow-water origin, probably in the eu- or mesophotic zone. The stylasterids colonized the hard substrates available and were successively removed and resedimented to form the skeletal fraction of the coastal wedge of the Pietra di Finale. The abundance of stylasterids is restricted to particular and limited situations in the Miocene of the Mediterranean, thus suggesting that their abnormal development is controlled by local rather than global factors

Coupling a distributed grid based hydrological model and MM5 meteorological model for flooding alert mapping

International audienceThe increased number of extreme rainfall events seems to be one of the common feature of climate change signal all over the world (Easterlin et al., 2000; Meehl et al., 2000). In the last few years a large number of floods caused by extreme meteorological events has been observed over the river basins of Mediterranean area and they mainly affected small basins (few hundreds until few thousands of square kilometres of drainage area) . A strategic goal of applied meteorology is now to try to predict with high spatial resolution the segments of drainage network where floods may occur. A possible way to reach this aim is the coupling of meteorological mesoscale model with high resolution hydrological model. In this work few case studies of observed floods in the Italian Mediterranean area will be presented. It is shown how a distributed hydrological model, using the precipitation fields predicted by MM5 meteorological model, is able to highlight the area where the major floods may occur

Coral assemblages and bioconstructions adapted to the depositional dynamics of a mixed carbonate-siliciclastic setting: the case study of the Burdigalian Bonifacio Basin (South Corsica)

Coral bioconstructions associated with mixed carbonate-siliciclastic settings are known to be strongly controlled by coastal morphology and paleotopography. A striking example is represented by the different types of coral bioconstructions and coral-rich deposits of the Cala di Labra Formation deposited in the coastal environment of the Bonifacio Basin (Corsica, France) during the Early Miocene. Detailed mapping on photomosaics allowed accurate documentation of the internal organization of coral deposits as well as lateral and vertical facies relationships. Four types of coral bioconstructions (CB) and one reworked coral deposits (RCD) have been recognized. The CB are represented by sigmoidal cluster reefs, coral carpets and skeletal conglomerates rich in corals. The RCD occurs in lens-shaped bodies intercalated within clinoforms composed of bioclastic loatstones and coarse packstones. The investigated bioconstructions can be contextualised in a coastal environment. In the upper shoreface corals developed in association with the oyster Hyotissa, above bioclastic conglomerates sourced by ephemeral streams and erosion of the granitic coastline. In the lower shoreface corals formed sigmoidal bioconstructions interpreted as cluster reefs, whereas coral carpets developed during a relative sea-level rise related to the middle Burdigalian transgressive phase. The reworked coral deposits can be interpreted as lobe-shaped deposits of coarse-grained bioclastic submarine fans formed at the base of the depositional slope of an infralittoral prograding wedge system

A superoxide dismutase biosensor for measuring the antioxidant capacity of blueberry based integrators

The antioxidant capacity of capsules containing blueberry based products which are included among the group of integrators owing to their antioxidant capacity and produced by various films was investigated. The results of the investigation are compared to rank these products in order to their antioxidant capacity. In order to measure antioxidant capacity, our laboratory has recently developed a special electrochemical method based on a superoxide dismutase (SOD) biosensor to determine the superoxide radical. The results obtained by applying the SOD biosensor method to various blueberry based integrators were compared with the results obtained with the spectrophotometric (FRAP) method based on N,N-dimethyl-p-phenylendiamine (DMPD-FeCl3) and with those obtained also using the ORAC fluorimetric (TRAP) method. One of the more interesting aspect of the article is the good agreement it evidences of the results of the three methods for measuring antioxidant capacity. The three methods differ among themselves: an Electron Transfer (ET) method, a Hydrogen Atom Trasnfer Metod (HAT) and an electrochemical based biosensor method of the Morning Superoxide Radical (MSR) type. It is also shown how the antioxidant capacity of the fresh vegetable is in any case always greater then of any food supplement obtained from the same type of vegetable

EFFECT OF AN INNOVATIVE ISOLATION SYSTEM ON THE SEISMIC RESPONSE OF CULTURAL HERITAGE BUILDING CONTENTS

An experimental study was conducted at the University of Pavia and at the EUCENTRE Foundation (Pavia, Italy) to assess the effectiveness of an innovative seismic isolation device at protecting cultural heritage building contents. The recently patented isolator, named “Kinematic Steel Joint (KSJ)”, is based on a multiple articulated quadrilateral mechanism and is entirely made of steel components obtained by simply cutting, folding, and pinning metal sheets, eventually employing stainless steel to limit corrosion issues. The trajectory imposed by the KSJ isolator to the supported mass combines horizontal with increasing vertical displacements, resulting in a pendulum-type motion with self-centering behavior. The friction developing within the pinned joints can be exploited to grant energy dissipation capacity to the device. The KSJ isolator can be manufactured with different sizes, payloads, and displacement ranges. In fact, seismic isolation can be applied at a global building level as an integrated system or as a retrofit solution in new or existing construction, respectively, or at a local scale as a passive protection technique for non-structural components. Despite their undeniable effectiveness in reducing the seismic accelerations transmitted to the isolated structure and to its content, currently available isolation devices may add significantly to the construction cost of buildings, and may require particular maintenance to preserve a stable performance over time. The proposed KSJ solution will allow for a reduction in manufacturing and maintenance burdens compared to established technologies. This paper discusses the main results of a shake-table test conducted at the EUCENTRE Foundation laboratories on an assembly with four prototypes of the KSJ device. The experimental setup included a 19-t rigid mass supported by the isolators, simulating the building superstructure, and four marble blocks installed above the rigid mass, representing non-structural rocking components such as parapets, pinnacles, statues, or other architectural ornaments. Moreover, a museum showcase with a small-scale replica of Michelangelo’s David was mounted above the rigid block, while two clay vases completed the setup, to encompass additional cultural heritage features. Accelerometers and potentiometers were deployed at several locations to monitor the kinematic response of the individual isolators, as well as their effect on the dynamic response of the rigid mass and of the different non-structural elements. The experiment was conducted first with the KSJ devices allowed to displace freely, then after fastening the rigid mass to the shake-table through post-tensioning rods, following the same incremental dynamic test sequence. This allowed comparing the response of the non-structural components with and without seismic isolation, to better understand the effect of the proposed isolation devices on the overall test assembly and on each sub-component

Thermally driven circulation in a region of complex topography: comparison of wind-profiling radar measurements and MM5 numerical predictions

The diurnal variation of regional wind patterns in the complex terrain of Central Italy was investigated for summer fair-weather conditions and winter time periods using a radar wind profiler. The profiler is located on a site where interaction between the complex topography and land-surface produces a variety of thermally and dynamically driven wind systems. The observational data set, collected for a period of one year, was used first to describe the diurnal evolution of thermal driven winds, second to validate the Mesoscale Model 5 (MM5) that is a three-dimensional numerical model. This type of analysis was focused on the near-surface wind observation, since thermally driven winds occur in the lower atmosphere. According to the valley wind theory expectations, the site – located on the left sidewall of the valley (looking up valley) – experiences a clockwise turning with time. Same characteristics in the behavior were established in both the experimental and numerical results. <P style="line-height: 20px;"> Because the thermally driven flows can have some depth and may be influenced mainly by model errors, as a third step the analysis focuses on a subset of cases to explore four different MM5 Planetary Boundary Layer (PBL) parameterizations. The reason is to test how the results are sensitive to the selected PBL parameterization, and to identify the better parameterization if it is possible. For this purpose we analysed the MM5 output for the whole PBL levels. The chosen PBL parameterizations are: 1) Gayno-Seaman; 2) Medium-Range Forecast; 3) Mellor-Yamada scheme as used in the ETA model; and 4) Blackadar

Penetrating particle ANalyzer (PAN)

PAN is a scientific instrument suitable for deep space and interplanetary missions. It can precisely measure and monitor the flux, composition, and direction of highly penetrating particles ($> \sim$100 MeV/nucleon) in deep space, over at least one full solar cycle (~11 years). The science program of PAN is multi- and cross-disciplinary, covering cosmic ray physics, solar physics, space weather and space travel. PAN will fill an observation gap of galactic cosmic rays in the GeV region, and provide precise information of the spectrum, composition and emission time of energetic particle originated from the Sun. The precise measurement and monitoring of the energetic particles is also a unique contribution to space weather studies. PAN will map the flux and composition of penetrating particles, which cannot be shielded effectively, precisely and continuously, providing valuable input for the assessment of the related health risk, and for the development of an adequate mitigation strategy. PAN has the potential to become a standard on-board instrument for deep space human travel. PAN is based on the proven detection principle of a magnetic spectrometer, but with novel layout and detection concept. It will adopt advanced particle detection technologies and industrial processes optimized for deep space application. The device will require limited mass (~20 kg) and power (~20 W) budget. Dipole magnet sectors built from high field permanent magnet Halbach arrays, instrumented in a modular fashion with high resolution silicon strip detectors, allow to reach an energy resolution better than 10\% for nuclei from H to Fe at 1 GeV/n