A new AMS (Accelerator Mass Spectrometry) beam line has been recently installed at CEDAD (Centre for Dating and Diagnostics)-university of Salento, Lecce, Italy for the detection by AMS of rare isotopes such as 10Be, 26Al, 129I and actinides. In this paper the performances of the new line for the measurement of 10Be are presented. Different tests were carried out in order to determine proper operating parameters and experimental conditions such as acceleration voltage, selected charge states and silicon nitride degrader thickness. The obtained results allow to assess the good performances of the new spectrometer in terms of boron suppression and background levels.

Bone samples from a Bronze age necropolis in Northern Italy, exposed to different combustion temperatures,were submitted to XRD (X-ray Diffraction), PIXE (Particle Induced X-ray Emission) and PIGE (Particle Induced Gamma Ray Emission) analyses in order to obtain information about their diagenetic state. Structural carbonate was then extracted by acid hydrolysis and used for 14C-AMS (Accelerator Mass Spectrometry) dating. These analytical techniques permitted the study of the effects of the combustion temperature on the crystallinity of the bone apatite and on its elemental chemical composition in terms of major, minor and trace elements. The results indicate that combustion at temperatures above 700 C induces changes in the bone crystalline structure, reducing the diagenetic uptake of elements from the burial environment.

We present the general design features and preliminary performances of a new system for the simultaneous AMS-14C and IRMS δ13C and δ15N measurements on samples with masses in the μg range. The system consists of an elemental analyzer (EA), a gas splitting unit (GSU), a IRMS system, a gas handling interface (GHI) and a sputtering ion source capable of accepting gaseous samples. A detailed description of the system and of the control software supporting unattended operation are presented together with the first performance tests carried out by analyzing samples with masses ranging from 8 μgC to 2.4 mgC. The performances of the system were tested in term of stability of the ion beam extracted from the ion source, precision and accuracy of the results by comparing the measured isotopic ratios with those expected for reference materials.

In the Porto Cesareo (Lecce, Italy) coastal area, submerged and semi-submerged archaeological evidence has been uncovered by recent preliminary surveys carried out in close collaboration with the local marine protected area (MPA): (a) a navis lapidaria wreck of the Roman imperial age; (b) various scattered and decontextualised finds; (c) a beached wreck, probably medieval; (d) some submerged built-structures that are part of the Bronze Age Scalo di Furno settlement; and (e) remains of structures (walls, buildings, burial areas). The last three pieces of evidence allow for the hypothesis of a significantly different ancient coastal landscape than that of the present and a ‘dynamic’ scenario over the centuries.

In the frame of the general efforts to reduce atmospheric CO2 emissions different efforts are being carried out to stimulate the use of non-fossil energy sources and raw materials. Among these a significant role is played by the use of waste in Waste to Energy (WTE) plants. In this case a relevant problem is related to the determination of the proportion between the bio and the fossil derived fraction in CO2 atmospheric emissions since only the share of energy derived from the bio-fraction combustion can be labelled as "renewable". We discuss the potential of radiocarbon in this field by presenting the results of different campaigns carried out by analysing CO2 sampled at the stack of different power plants in Italy with different expected bio-content of the released carbon dioxide. The still open issues related to the calculation procedures and the achievable precision and accuracy levels are discussed.

Waterlogged wood samples of Ulmus sp. and Fraxinus sp. from the ancient harbor of Otranto in Southern Italy were radiocarbon dated by accelerator mass spectrometry (AMS) and examined for physical and chemical changes to assess the degree of degradation. The analyzed woods were dated to the 2nd half of the twelfth – 1st half of the thirteenth centuries AD. The results of all the used methods (maximum water content, basic density, shrinkage, XRD analysis and holocellulose content) indicated a low level of degradation in the inner part of the wooden find. The outer and middle part, on the other hand, showed a greater degradation level. An important result is the identification of a not homogeneous degradation in the different parts of the examined wooden block, which will affect the design of the consolidating treatment

SIBA Get it!(opens in a new window)|View at Publisher| Export | Download | Add to List | More... Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms Volume 331, 15 July 2014, Pages 168-171 Comparative study of metal and non-metal ion implantation in polymers: Optical and electrical properties (Article) Resta, V.a , Quarta, G.a, Farella, I.b, Maruccio, L.a, Cola, A.b, Calcagnile, L.a a Department of Engineering for Innovation, University of Salento, Via Monteroni, Lecce I-73100, Italy b Institute for Microelectronics and Microsystems, Unit of Lecce, National Council of Research (IMM/CNR), Lecce I-73100, Italy View references (28) Abstract The implantation of 1 MeV metal (63Cu+, 107Ag+, 197Au+) and non-metal ( 4He+, 12C+) ions in a polycarbonate (PC) matrix has been studied in order to evaluate the role of ion species in the modification of optical and electrical properties of the polymer. When the ion fluence is above ∼1 × 1013 ions cm-2, the threshold for latent tracks overlapping is overcome and π-bonded carbon clusters grow and aggregate forming a network of conjugated CC bonds. For fluences around 1 × 1017 ions cm-2, the aggregation phenomena induce the formation of amorphous carbon and/or graphite like structures. At the same time, nucleation of metal nanoparticles (NPs) from implanted species can take place when the supersaturation threshold is overcome. The optical absorption of the samples increases in the visible range and the optical band gap redshifts from 3.40 eV up to 0.70 eV mostly due to the carbonization process and the formation of C0x clusters and cluster aggregates. Specific structures in the extinction spectra are observed when metal ions are selected in contrast to the non-metal ion implanted PC, thus revealing the possible presence of noble metal based NPs interstitial to the C0x cluster network. The corresponding electrical resistance decreases much more when metal ions are implanted with at least a factor of 2 orders of magnitude difference than the non-metal ions based samples. An absolute value of ∼107 Ω/sq has been measured for implantation with metals at doses higher than 5 × 1016 ions cm-2, being 1017 Ω/sq the corresponding sheet resistance for pristine PC.

Most of the environmental studies performed in the Western Desert of Egypt have dealt with climate change since the Late Pleistocene, notably with the humid Holocene (10000 to 4500 cal. BC) and following desertification. In the last dry period of the Holocene, human societies had to cope with changing environments and they selected refuges where water was permanently available. Some of the archaeological investigations in the Western Desert have studied the available water resources and the role of irrigation in the building of soils. In some cases, they have explained the abandonment of sites by the progressive depletion of water resources. This paper focuses on the site of Amheida (the Roman Trimithis) located in the Dakhla depression in the Western Desert of Egypt. It is an elongated area located south of a limestone plateau, where spring mounds provided abundant water during the period of occupation, which lasted from the Old Kingdom (2700 cal. BC) to the Late Roman period (end of the 41th century AD). Trimithis was abandoned after a long period of prosperity. The reasons for its abandonment, as well as that of other settlements in the oasis in the same period, have not been clarified yet. Geoarchaeological surveys carried out in 2011 and 2013 point to several phases including 1) the use of a spring mound during part of the Pharaonic period (2700 to 1069 cal. BC) and the formation of irrigation soils in the vicinity of spring mounds from the Late Pharaonic times (712 to 332 BC) to the beginning of the Roman period (30 BC); 2) the degradation of these soils by wind deflation in the irrigated perimeter during the early Roman period; 3) a recovery until the 3rd century AD, made possible by the digging of wells, before; 4) a severe phase of deflation and sand drifting which destroyed the irrigation soils and forced farmers to till the poorly irrigated bedrock.The Trimithis case exemplifies the way former societies could cope with harsh constraints (aridity, drifting sand and wind erosion) as long as water was plentiful. Water scarcity due to the progressive depletion of groundwater resources was probably compensated by an increase in human labour until thresholds were crossed, recovery being impossible due to water scarcity. A model summarizes the main findings of this study.

The implantation of 1 MeV 63Cu+ ions in polycarbonate (PC) matrices has been carried out in order to evaluate the morphological and structural modifications induced in the polymer as a function of the ion fluence in the range 5 × 1013 ions cm-2 to 1 × 1017 ions cm-2. Atomic Force Microscopy analysis reveals a significant roughness increase of the polymer surface only for fluences higher than 5 × 1016 ions cm-2 with the presence of hillock structures which surface density increases with increasing the ion fluence. X-ray Diffraction measurements of PC implanted with fluences in the range between 5 × 1015 at cm-2 and 5 × 10 16 at cm-2 reveal an increase of the disorder inside the PC matrix, as a consequence of the damaging process induced by the ion irradiation. Evidences about the presence of exotic phase structures ascribed to both cubic Cu2O and cubic Cu have been found.

We present the general layout and the design features of the new beam line at CEDAD (Centre for Dating and Diagnostics) of the University of Salento, Italy, dedicated to the analysis of the rare isotope 10Be optimized for the 10B isobar suppression using the passive degrader in combination with a high resolution gas ionization detector. The layout of the beam line will also offer the possibility to analyze 26Al, 129I and actinide isotopes. The ion optics simulations, the characteristics of the dispersive elements, the detection and control systems are presented together with the expected performances.

Accelerator mass spectrometry (AMS) radiocarbon analyses were performed on biobased unsaturated polyester resins in order to assess the potential of the method for the determination of the bio-fraction. Different resins were synthesized in the laboratory with different proportions of raw materials of biogenic origin, and analyzed both in the liquid and in the solid form. As a preliminary step of the study, both the biobased and the fossil-derived raw materials were analyzed in order to determine their 14C content. A comparison of the obtained results with the expected ones allowed us to investigate the potential of the 14C method in this field as well as to address some still open issues such as the levels of uncertainty and accuracy as related to the calculation procedures, the correction for isotopic fractionation, and the effect of the presence of volatile components in the analyzed materials.

Various samples extracted from human tissues (with different radiocarbon turnover rates) of a post-bomb human body were submitted to accelerator mass spectrometry (AMS) 14C dating: hair; a cortical fraction of a skull bone; a trabecular fraction of a pubic symphysis; and enamel extracted from permanent teeth with different dates of formation were analyzed. The analyzed samples showed varying 14C concentrations corresponding to different times of formation or different turnover rates. The implications of the results in forensics studies are discussed. © 2013 by the Arizona Board of Regents on behalf of the University of Arizona.

A dedicated sample processing line for the extraction of dissolved inorganic carbon (DIC) from seawater and groundwater for accelerator mass spectrometry (AMS) radiocarbon analysis has been developed at CEDAD, the Center for Dating and Diagnostic of the University of Salento, Lecce, Italy. The features of the new system are presented together with tests carried out to determine its functionality and background levels. The first results obtained at CEDAD for analyzing seawater samples taken from the Northern Adriatic compare well with results obtained for the same samples analyzed at ETH Zurich.

Radiocarbon dating was first applied to historic lime mortars during the 1960s. However, despite the relative simplicity of the technique in principle, a number of subsequent studies have highlighted important aspects that should be considered. One of the most significant of these challenges arises from sample contamination by carbonaceous substances such as incompletely burnt limestone and aggregates of fossil origin containing “dead” 14C. More recent studies have shown that in the majority of old lime-based mixtures the contamination problem can be avoided through selection of pure lime lumps. These particular types of lumps are believed to originate from areas where the lime is incompletely mixed with the aggregate. It has been demonstrated that even a single lime lump can provide sufficient material for a 14C date of the mortar from which the lump was taken (Pesce et al. 2009). This paper describes the practical challenges associated with location, extraction, and preparation of 4 lime lumps coming from 2 new sites for 14C dating. These include distinguishing the lime lumps from other lumps present in the matrix and the removal of material surrounding the lime lump. The coherence of 14C dating with other archaeological information on the chronology of historic sites is highlighted through case studies.

Analytical methods based on particle accelerators are widely used in cultural heritage diagnostics and archaeological sciences from the absolute dating of organic materials by means of radiocarbon accelerator mass spectrometry (AMS) to the analysis of the elemental composition of a wide range of materials (metals, obsidians, pottery) via ion beam analysis (IBA) techniques. At CEDAD (Centre for Dating and Diagnostics), the accelerator facility of the University of Salento, AMS 14C dating and PIXE (particle-induced X-ray emission)-PIGE (particle-induced gamma-ray emission) compositional analysis in external beam mode are combined to study certain archaeological materials. We present a review of the combined application of these analytical methods in the study of casting cores of the Riace bronzes, 2 classical Greek statues of extraordinary importance for the history of art.

The aim of this work was to determine the provenance and the content of a group of archaic transport amphorae of different typologies retrieved during the archaeological excavations in the archaic settlement of Castello di Alceste (S.Vito dei Normanni-Br). We analysed a group of 16 samples belonging mainly to “Corinthian B” amphorae, which are widely diffused in the western Mediterranean basin and in Greece, but whose geographical provenance is still under discussion. XRF/FP analyses revealed that the amphorae were manufactured in three different areas of the Mediterranean: southern Italy, Ionian Islands and Corinth. GC-MS analyses revealed that most of the amphorae contained wine markers, together with pine resin, probably used as a sealant for the vessel or an additive to preserve wine. The contemporary presence of oil or animal fats in some containers suggests a possible reuse of the amphorae to store and preserve other foodstuffs

The presence of a coralligenic-like bioherm constituted by boulders up to 1.2 m in diameter cemented by bioconcretions of calcareous algae and Vermetids spp. has been recognized in the southernmost part of Kerkira Island. This biostructure is placed at up to w1.4 m above the present mean sea level. A few hundred meters north, well developed beach rocks are at about the same elevation. The morphological continuity of these landforms allows us to hypothesize that a recent coseismic uplift interested this area. AMS age determination has been performed on different Vermetids sampled in the upper part of the raised bioherm. Moreover, a complete review of the chronological data cited in the bibliography high- lights the difficulties in the use of some bioindicators as chronologically precise sea level indicators. The entire data set suggests a Late Holocene tectonic behaviour characterized by sequences of subsidence and coseismic uplift. In particular, the age of the raised bioherm suggests that a coseismic uplift occurred w3 ka BP due to an earthquake of regional interest capable of generating a strong tsunami that impacted the nearest coast of Lefkada Island and the Plaghia Peninsula.

La mummia scoperta nel sarcofago ligneo di Ankhpakered, sacerdote del dio Min, è stata studiata presso il CEDAD (Centro di Datazione e Diagnostica) dell'Università del Salento, Italia. La TC, eseguita sulla mummia dal team multidisciplinare del Mummy Project di Milano, ha evidenziato caratteristiche insolite, facendo ipotizzare un riutilizzo del sarcofago. Diversi campioni sono stati prelevati per via endoscopica per essere sottoposti ad analisi AMS (Accelerator Mass Spectrometry) per la datazione al radiocarbonio, effettuate presso il CEDAD, e ad analisi FTIR (Fourier Transform Infrared).

A new experimental set-up dedicated to the simultaneous measurements of stable carbon and nitrogen isotopic ratios by IRMS (Isotope Ratio Mass Spectrometry) and 14C by AMS (Accelerator Mass Spectrometry) has been installed at CEDAD (Centre for Dating and Diagnostics)-University of Salento. The new set-up is formed by different functional blocks: an elemental analyzer, an IRMS spectrometer, a gas handling unit and a new hybrid sputtering ion source, connected to the AMS system. The general features of the new system are presented as well as the technical solutions adopted for its integration with the existing AMS system. Different tests were performed by analyzing samples of known isotopic composition and of different masses in order to define optimal operating conditions. In particular it is shown how radiocarbon measurements with precision of 0.6–0.7% and 1% are possible with the new system on samples of mass of the order of ∼20 ug and∼10 ug, respectively. Background levels of the order of 10−14 (14C/12C) have been also demonstrated. The new system has then significantly extended the experimental potential of the Centre in several research fields where the possibility to date very low mass samples is either a crucial advantage or mandatory such as in environmental sciences and cultural heritage dating.

We report about the nanoclustering induced by oxygen‐implantation in silicon. A tandem‐type accelerator, with a maximum acceleration voltage of 3 MV, equipped with a sputtering ion source suitable for the production of high current ion beams by sputtering of solid cathodes has been used. The surface modifications and the structure of nanoclusters are investigated. The topographic images, obtained by scanning tunnelling microscope showed that the surface is covered with a dense array of tetragonal nanostructures oriented with respect to the substrate. Raman spectroscopy data allowed us to estimate an average cluster size of about 50 nm. Resistivity and all effect measurements evidenced that the electron transport in the implanted silicon samples is affected by the nanoclusters array and it could be explained by thermally activated hopping between localized states.

1 MeV copper ions were implanted in polycarbonate (PC) matrices with fluences ranging from 5 × 1013 ions cm-2 to 1 × 1017 ions cm-2 in order to modify the optical and electrical properties of the polymer host. Increasing the ion fluence, an increase of the overall absorption and a redshift of the optical band gap were observed, from the initial value of 3.40 eV for the pristine PC to 0.80 eV measured for 1 × 1017 ions cm-2. For fluences above 5 × 1014 ions cm-2 a broad optical absorption bands at 450-475 nm and 520 nm were observed and, from 1 × 1016 ions cm-2, an additional band appeared at 570 nm. Both bands redshift when the fluence is increased. On the contrary, the optical response of the highest fluence sample is characterized by an overall band at 580 nm. The chemical modifications observed in the polymer ranges from induced -OH stretching, CO and -CC- double bonds and -CC and CH triple bonds formation, as the ion fluence increases. The implantation process affects the electrical properties of the polymer inducing a strong reduction in sheet resistance when ion fluence exceeds 5 × 1016 ions cm-2. A value of ∼7.1 × 107 Ω/sq has been obtained for the highest fluence, i.e. about 10 order of magnitude lower than the pristine PC.

Hydrogenated amorphous carbon coatings, deposited by low pressure plasma to minimize the wear of C100 steel components, were optimized and characterized. In order to ensure good adhesion of the films to the steel surface, a thin Ti interlayer was deposited, by magnetron sputtering, before the plasma deposition. The chemical characterization of the deposits was performed by means of RAMAN, XPS, RBS and ERDA analysis, while nanoindentation, nanoscratch and nanowear tests allowed to estimating the tribomechanical properties of the deposits, with the aim of evaluating their scuff-resistance. It was found that the optimized plasma deposited hydrogenated amorphous carbon coatings were well adherent to C100 steel and increased more than 70% its surface hardness.

Precious corals are some of the most valuable livingmarine resources, growing and commercially exploited only in limited areas of the world, namely the Mediterranean Sea and the Northern Pacific Ocean. Their skeleton is formed by calcium carbonate crystallized in the form of calcite whereas their color is because of the presence of partially demethylated polyene pigments. Recently, Pacific corals have been included in the appendix II of CITES list, whileMediterranean corals are still excluded. Different Corallium species of Corallidae family (e.g. Coralliumrubrum, Corallium elatius and Coralliumsecundum) collected from different locations of the Mediterranean Sea and the Pacific Ocean were analyzed by Raman spectroscopy for the characterization of the reddish pigment and by X-ray fluorescence (XRF) for the determination of the chemical composition of their skeletons, in order to obtain molecular and elemental data with two relatively easy and non-destructive techniques, which can be used quite steadily for authentication purposes. Raman analysis demonstrated the presence of specific vibrational bands useful to identify the colored pigments as a mixture involving methylated and demethylated polyenes such as carotenoids and parrodienes, characterized by the presence of ―CH3 groups along the polyene chain. The ratio between the Raman signal and fluorescence background was found to vary as a function of the macroscopic color of the coral, but Raman analyses resulted inadequate for distinguishing between corals having similar color but different origins. On the other side, XRF data provided reliable information for an appropriate separation between Pacific and Mediterranean corals at the elemental level. The results of this study will be of great relevance for the authentication and identification of the origin of corals in trade market by means of completely non-destructive techniques.

Obsidian samples recovered in archaeological contexts in Southern Italy were analysed by PIXE (Particle Induced X-ray Emission) and PIGE (Particle Induced Gamma Ray Emission) for the quantitative determination of both major and trace elements composition. The archaeological contexts were absolutely dated to the 5th millennium BC by mean of AMS (Accelerator Mass Spectrometry) radiocarbon dating analyses carried out on associated organic materials such as charcoal and human bones. The comparison of the compositional results obtained for the analysed samples with published data available for the known obsidian sources in the Mediterranean allowed to identify the sources of the raw material, giving an important contribution to the reconstruction of the ancient trade and exchange routes in Southern Italy prehistory. © 2011 Elsevier B.V. All rights reserved.

The San Lorenzo Cathedral of Alba is a Romanesque church (rebuilt in Gothic epoch) located in northwest Italy. Since 2007, this church has been subjected to renovations and archaeological excavations that led to the finding of the lower part of the basin and the water drainage pipe of a baptismal font of unknown age. Thermoluminescence and radiocarbon dating have been carried out respectively on some ceramic elements and lime mortar samples used in both the pipe and basin of the font. Thermoluminescence results suggest that some of the bricks may have been reused from previous structures while 14C results suggest that the font was built between the 9th and the 11th centuries AD, most probably in the 10th century AD.

Grotta della Monaca is a karstic cave in Calabria (southern Italy) that plays an important role in reconstructing the oldest strategies for the acquisition of mineral resources in the Mediterranean. In fact, systematic archaeological excavations carried out by the University of Bari allowed the identification of intense prehistoric mining activities aimed at the exploitation of iron and copper ores. Archaeological evidence suggests different phases of frequentation of the cave spanning from the Upper Paleolithic, Neolithic, Copper and Bronze ages up to the Middle Ages. In order to establish an absolute timeframe for the different phases, a radiocarbon dating campaign was carried out and the results presented in this paper.

The irradiation of a polycarbonate (PC) matrix with 28Si+ ions has been performed by selecting three different energies: 0.5 MeV, 1.0 MeV and 2.0 MeV. The comparative study of the modifications induced in the polymer as a function of the incident ion beam energy has been carried out in the range of fluences between 5 × 1013 ions cm-2 and 1 × 1015 ions cm-2. The changes induced in the structure of the matrix towards the production of conducting plastics for optoelectronics devices have been evaluated by Raman and Photoluminescence spectroscopy. The carbonization process of the polymer generates a network made of sp2-bonded graphitic clusters embedded in a sp3-bonded matrix. The amount of nanocrystalline-graphite with respect to amorphous-carbon increases as ion energy and fluence increase, in accordance with the increase of the sp2-order arrangement. With 0.5 MeV the modification process is at an initial stage so that the changes, in terms of structure and PL emission, are observed only for the highest fluence, while for 1.0 MeV it has been achieved a higher density of small cluster with an order and homogeneity even better than for 2.0 MeV. The irradiation process with a suitable set of experimental parameters allows tuning the PC emission from ∼510 nm (pristine matrix) up to ∼550-600 nm.

Magnetic field effects are diffused among living organisms. They are mainly studied with static or extremely low frequency fields, while scarce information is available for pulsed fields. This work is devoted to the study of the interaction between Drosophila melanogaster, both adults and larvae, and pulsed magnetic fields. We exposed the organisms to a peak field of 0.4 T, lasting for about 2 μ s, within an ad hoc designed copper coil. Adult individuals didn't present any deregulation of repetitive sequences in the germ line of Drosophila. Instead, we noticed a marked magnetic field effect in larvae. Polytene chromosomes coming from treated individuals showed the presence of heat shock puffs; the same organisms revealed also an upregulation of the genes encoding for the Hsp70 protein. These observations suggest that the larvae underwent an oxidative stress caused by the modulation of free radicals' yield induced by the magnetic field through a radical pair mechanism.

Different research activities are in progress at the Centre for Dating and Diagnostics (CEDAD), University of Salento, in the field of environmental monitoring by exploiting the potentialities given by the different experimental beam lines implemented on the 3 MV Tandetron accelerator and dedicated to AMS (Accelerator Mass Spectrometry) radiocarbon dating and IBA (Ion Beam Analysis). An overview of these activities is presented by showing how accelerator-based analytical techniques can be a powerful tool for monitoring the anthropogenic carbon dioxide emissions from industrial sources and for the assessment of the biogenic content in SRF (Solid Recovered Fuel) burned in WTE (Waste to Energy) plants.

The synthesis of new β-Ga2O3 microstructures was achieved through rapid annealing of GaSe single crystal at 850 °C in oxygen-ammonia co-flow for 30-120 min duration. The obtained micro-flowers and micro-leaves were carefully characterized through X-ray diffraction, scanning electron microscopy and Raman spectroscopy. SEM images demonstrated that the product consisted of flower-shaped microstructures, which as time elapsed evolved into leaves-like dendritic microstructures. These microstructures started off directly from oxidized single crystal. A possible growth mechanism was also proposed. Experimental results evidenced that synthesized microstructures exhibited good photocatalytic activity, better than commercial TiO2 powder (Degussa P25).

The construction of the Baptistry of Saint John has a debated and uncertain history; the hypothesis on its main construction phases may span from the Roman period to the 13th century, according to different authors. This uncertainty is mainly due to the lack of primary sources and certain dating issues. By combining dendrochronological analysis and radiocarbon dating, some light was shed on the building's history. Open at least from 897, in 1059 Pope Nicholas II re-consecrated the baptistry after several renovations. Around that period, the octagonal dome was probably built by using chestnut beams to tie the structure together. The dendrochronological analysis dated the silver fir element to 1268. This element possibly represents a replacement coincident with the period, between 1270 and 1300, when a substantial part of the mosaics of the dome was positioned.

Archaeological surface surveys carried out near Salve in southern Italy led to the identification of about 90 stone mounds spread over an area of about 100 ha. Systematic archaeological investigations allowed to identify the mounds as funeral structures with some having megalithic features. In the necropolis, both the inhumation and cremation rituals are evident, in some cases within the same mound. This article presents the results of an accelerator mass spectrometry (AMS) radiocarbon dating campaign carried out on different kinds of samples recovered from several structures: unburned and cremated bones, charcoals, and organic residues extracted from pottery sherds. The results allowed to assess the chronology of the site and to shed new light on the different funeral practices in Copper Age southern Italy.

This paper concerns the changes occurred over both decennial and millennial spans of time in a sponge assemblage present in coralligenous biogenic build-ups growing at 15 m depth in the Ligurian Sea (Western Mediterranean). The comparison of the sponge diversity after a time interval of about 40 years (1973-2014) showed a significant reduction in species richness (about 45%). This decrease affected mainly the massive/erect sponges, and in particular the subclass Keratosa, with a species loss of 67%, while the encrusting and cavity dwelling sponges lost the 36% and 50%, respectively. The boring sponges lost only one species (25%). This changing pattern suggested that the inner habitat of the bioconstructions was less affected by the variations of the environmental conditions or by the human pressures which, on the contrary, strongly affected the species living on the surface of the biogenic build-ups. Five cores extracted from the bioherms, dating back to 3500 YBP, allowed to analyse the siliceous spicules remained trapped in them in order to obtain taxonomic information. Changes at generic level in diversity and abundance were observed at 500/250-years intervals, ranging between 19 and 33 genera. The number of genera showed a sharp decrease since 3500-3000 to 3000-2500 YBP. After this period, the genera regularly increased until 1500-1250 YBP, from when they progressively decreased until 1000-500 YBP. Tentatively, these changes could be related to the different climatic periods that followed one another in the Mediterranean area within the considered time span. The recent depletion in sponge richness recorded in the Ligurian coralligenous can be considered relevant. In fact, the analysis of the spicules indicated that the sponges living in these coralligenous habitats remained enough stable during 3000 years, but could have lost a significant part of their biodiversity in the last decades, coinciding with a series of warming episodes.

The timing of the colonization of Sardinia by mammalian fauna and anatomically modern humans (AMH) is currently under debate. The understanding of the geological and palaeoclimatological conditions that characterized the Late Pleistocene and the Holocene is essential to investigate colonization processes and requires an integrated multidisciplinary approach. In this research we combine for the first time new radiometric dating, field evidence of relative sea-level changes (RSL), sea-level and glacial-isostatic adjustment modelling, stratigraphical, palaeontological, palaeoecological and isotope analyses that were performed on sites and finds from the Porto Conte and Capo Caccia area (Alghero, NW Sardinia). The most important Late Pleistocene fossiliferous deposits in Sardinia have been discovered in this part of the island. Modelled palaeogeographical reconstructions of the Porto Conte area combined with the inferred environmental context and chronology of Late Pleistocene faunal assemblages from Medusa-Dragonara Cave suggest that Homo sapiens did not inhabit this area before the Holocene. Our results support the hypothesis that human presence in Sardinia during the Last Glacial Maximum was at best sporadic.

The Centre for Dating and Diagnostics (CEDAD) at the University of Salento was established in 2001 and became fully operational for routine 14C radiocarbon dating in 2003. The facility has been continuously upgraded over the years with the installation of different beam lines for high energy ion implantation, IBA analyses both in vacuum and in air and nuclear microprobe. In 2011 a second AMS beamline was installed consisting of a dedicated high energy mass spectrometer for the AMS analysis of rare nuclides such as 10Be, 26Al, 129I and actinides. First tests on 10Be allowed to optimize the operating parameters resulting in the proper separation of 10Be from the interfering isobar 10B. In this paper we present the further tests and optimizations which resulted in an enhancement of the overall transmission efficiency, the reduction of the background (in the 10-15 range) and in the possibility to obtain precision levels in routine 10Be/9Be measurements of the order of 0.5%. Furthermore the first results obtained for the analysis of 26Al and 129I are also presented.

The ancient Egyptian mummy discovered in the wooden coffin of Ankhpakhered, priest of the god Min, has been studied at CEDAD (Centre for Dating and Diagnostics) at the University of Salento, Italy. The CT scan, performed by the multidisciplinary team of the Mummy Project of Milan, highlighted unusual features of the mummy, suggesting a reuse of the sarcophagus. Furthermore, specimens were taken via endoscopy for accelerator mass spectrometry (AMS) radiocarbon dating and Fourier transform infrared (FTIR) analyses, which have been carried out at CEDAD.

Out of the staters collection of the National Archaeological Museum of Taranto, during the full examination of about one hundred coins minted by the Greek colony of Taras between the V century BC and the III century BC, our attention has been devoted to a lead coin, which has been regarded for many years as a genuine silver coin. This artifact, entry number 13 in the inventory list for the Parabita hoard, has been studied with the combined use of surface and micro-analytical techniques (SEM, EDX, PIXE, XRD). The joint use of different analytical techniques allowed us to obtain information about the morphology, the structure and the chemical composition of the analysed coin, that revealed a lead core coated with a bi-layer of copper and silver.