3,857 research outputs found
FIRST EVIDENCE OF OPUNTIA FICUS INDICA LEAVES USED AS SURFACE FINISHING TREATMENTS ON THE PIETRA LECCESE
Lecce stone belongs to the group of Miocene limestone and is distributed in many areas of
the Salento peninsula. The great part of the historical buildings, both religious and civil, in
this area have been constructed with this porous and soft material.
In the past, various methods and recipes have been used to protect the surfaces and ensure
their longevity. However, these ancient "recipes" are unidentified, because these techniques
were known only by the artisans who used them [2].
For this purpose, selected religious and civil buildings in the territory of the province of
Lecce, made of Lecce stone, not yet restored and possibly treated with some of these
unknown recipes because of their good conservation state, were studied and the presence
of surface treatments was investigated.
Samples were analysed by Py/GC-MS with and without thermally assisted hydrolysis and
methylation using tetramethylammonium hydroxide (TMAH). The results of the analyses
showed that these buildings have been protected with different natural products. Moreover,
for the first time, chemical biomarkers demonstrating the use of prickly pear leaves (Opuntia
ficus indica [3]) as protective surface finishes have been identified
The use of Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS) in the study of Cultural Heritage
Several analytical techniques are actually employed for the study of Cultural Heritage and permit to identify production methodologies, constituent materials, degradation products, dating and provenance of the objects examined; elemental analyses provide precious information to archaeologists, art historians, restorers and analysts, opening a door into the past. Those techniques capable of ensuring versatility of application, sensitivity and non-destructive or micro-invasive analysis are generally requested. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICPMS), by virtue of its effective lateral resolution, sensitivity to most elements and capacity of outdoing limitations due to the low quantity of accessible samples, fulfils these requirements. Multivariate statistical techniques applied to the elemental data permit classification and provenance of artistic objects and allow to confute or confirm historical hypotheses. In the present work several case studies, addressed recently by the authors concerning objects of artistic and historical value, are outlined: pottery and glazes of Vesuvian area (Campania, Italy), fibulae of Egnatia (Puglia, Italy), inks of painting of Sant’Irene by Giuseppe Verrio and lime mortars from Siponto (Puglia, Italy). For each of the presented activity, results, advantages and drawbacks of the LA-ICPMS were discussed
ARCHAEOLOGICAL MATERIALS FROM GABII (CENTRAL ITALY): KNOWLEDGE OF OFFERINGS AND RITUALS AT THE INFANT BURIALS THROUGH AN INTEGRATED APPROACH
The ancient Latin city of Gabii is situated 18 km (11.2 miles) to the east of Rome (Central
Italy) along the modern Via Prenestina. Gabii was a renowned city in Roman times,
particularly during the Republican period and there are various influences in the site that can
be identified in Roman culture itself. Gabii is also one of the most significant and important
archaeological sites in the territory of the Municipality of Rome and due to its
characteristics, it represents today an extraordinary research context. From the excavations
carried out in the past it is possible to see how, under the soil, the main structures and
buildings of the ancient city are still largely preserved. Among the various testimonies of the
past, the tombs, and the micro and macro remains that these contain, represent an
opportunity to investigate such practices in the context of Early Iron Age and Orientalizing
Latium. In particular, the finds from the Area D baby burials of Gabii enriched the existing
dataset so far significantly, allowing us to explore funerary ritual behavior in a more
systematic way.
This work reports the results of the detailed examination of four tombs (Tombs 30, 50, 51
and 52) of archaeological site. The field strategy for the excavation of the tombs was geared
from the start towards both the systematic retrieval of archaeobotanical and
zooarchaeological remains and the sampling for organic residue analysis. Aiming for total
recovery, the sediments from the tomb fills were sifted in their entirety as their stratigraphic
excavation progressed, and samples were taken for flotation. This careful screening allowed
for the detection of concentrations of organic material that represent plant and/or animal
depositions. The excavation and removal of the grave goods was carried out following strict
protocols for residue sampling, minimizing the risk of organic contamination. Samples were
analysed by High Temperature Gas Chromatography/Mass Spectrometry (HTGC/MS) and
Gas chromatography/Combustion/Isotope ratio mass spectrometry (GC-C-IRMS). For each
burial, a subset of vessels including both closed and open shapes was selected, such as cups,
open bowl without foot, amphoretta, amphora with dots, Kantharos, plate on a foot, olla,
and olpe in bucchero.
The results demonstrate the still largely unexploited potential of this sort of integrated
studies, encouraging us to expand the application of chemical methods to contexts from
other well–controlled excavations
Proanthocyanidins from \u3cem\u3eHedysarum, Lotus\u3c/em\u3e and \u3cem\u3eOnobrychis\u3c/em\u3e spp. Growing in Sardinia and Sicily and Their Antioxidant Activity
Proanthocyanidins (PA), or condensed tannins, are a class of natural polyphenolic compounds, occurring in numerous plant species, including a number of economically significant forage legumes. These compounds are polymers of flavan-3-ols, and typically contain from 2 to 20 units. Their biological significance is still being debated and, in recent years, a great deal of attention has been focused on their role in ruminant nutrition. Evidence has indicated that PA, in a moderate concentration (0.5-5% DM), may have considerable importance in protecting dietary proteins against microbial degradation in the rumen, and in preventing bloat. The antioxidant activity (AA) is also an important feature for animal well-being (Barry & McNabb, 1999). In order to study the PA content related to the antioxidant activity, samples of Hedysarum, Lotus and Onobrychis spp. from Mediterranean environments have been considered and investigated
A Study of the B-V Colour Temperature Relation
We attempt to construct a B-V colour temperature relation for stars in the
least model dependent way employing the best modern data. The fit we obtained
with the form Teff = Teff((B-V)0,[Fe/H],log g) is well constrained and a number
of tests show the consistency of the procedures for the fit. Our relation
covers from F0 to K5 stars with metallicity [Fe/H] = -1.5 to +0.3 for both
dwarfs and giants. The residual of the fit is 66 K, which is consistent with
what are expected from the quality of the present data. Metallicity and surface
gravity effects are well separated from the colour dependence. Dwarfs and
giants match well in a single family of fit, differing only in log g. The fit
also detects the Galactic extinction correction for nearby stars with the
amount E(B-V) = 0.26 +/-0.03 mag/kpc. Taking the newly obtained relation as a
reference we examine a number of B-V colour temperature relations and
atmosphere models available in the literature. We show the presence of a
systematic error in the colour temperature relation from synthetic calculations
of model atmospheres; the systematic error across K0 to K5 dwarfs is 0.04-0.05
mag in B-V, which means 0.25-0.3 mag in Mv for the K star range. We also argue
for the error in the temperature scale used in currently popular stellar
population synthesis models; synthetic colours from these models are somewhat
too blue for aged elliptical galaxies. We derive the colour index of the sun
(B-V)sun = 0.627 +/-0.018, and discuss that redder colours (e.g., 0.66-0.67)
often quoted in the literature are incompatible with the colour-temperature
relation.Comment: AASLaTeX (aaspp4.sty),36 pages (13 figures included), submitted to
Astronomical Journal, replaced (typo in author name
Ergodicity criteria for non-expanding transformations of 2-adic spheres
In the paper, we obtain necessary and sufficient conditions for ergodicity
(with respect to the normalized Haar measure) of discrete dynamical systems
on 2-adic spheres of radius
, , centered at some point from the ultrametric space of
2-adic integers . The map is
assumed to be non-expanding and measure-preserving; that is, satisfies a
Lipschitz condition with a constant 1 with respect to the 2-adic metric, and
preserves a natural probability measure on , the Haar measure
on which is normalized so that
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