XRF analyses for the study of painting technique and degradation on frescoes by Beato Angelico: first results

Beato Angelico is one of the most important Italian painters of the Renaissance period, in particular he was a master of the so-called “buon fresco” technique for mural paintings. A wide diagnostic campaign with X-Ray Fluorescence (XRF) analyses has been carried out on three masterworks painted by Beato Angelico in the San Marco monastery in Florence: the Crocifissione con Santi, the Annunciazione and the Madonna delle Ombre. The latter is painted by mixing fresco and secco techniques, which makes it of particular interest for the study of two different paintings techniques of the same artist. Then the aim of the study was focused on the characterization of the painting palette, and therefore the painting techniques, used by Beato Angelico. Moreover, the conservators were interested in the study of degradation processes and old restoration treatments. Our analyses have been carried out by means of the XRF spectrometer developed at LABEC laboratory at Istituto Nazionale di Fisica Nucleare in Florence (Italy). XRF is indeed especially suited for such a kind of study, allowing for multi-elemental, nondestructive, non-invasive analyses in a short time, with portable instruments. In this paper the first results concerning the XRF analysis are presented

Enhanced RF Behavior Multi-Layer Thermal Insulation

Abstract This paper shows that it is possible to exploit the modulated metasurface concept to control the unwanted coupling between antennas that are installed on the same satellite. The metasurface is combined with a Multi-Layer thermal Insulation blanket to reduce its specular reflection by spreading the energy incoherently in the surrounding space. In the design, sub-wavelength radiating elements printed on thin substrate have been used to make the metasurface response azimuthally independent, and to keep the weight of blanket down. The comparison between simulations and measurements confirms the validity of the idea

Pointer Provenance in a Capability Architecture

We design and implement a framework for tracking pointer provenance, using our CHERI fat-pointer capability architec- ture to facilitate analysis of security implications of program pointer flows in both user and privileged code, with mini- mal instrumentation. CHERI enforces pointer provenance validity at the architectural level, in the presence of complex pointer arithmetic and type casting. CHERI present new op- portunities for provenance research: we discuss use cases and highlight lessons and open questions from our work.DARPA/AFRL FA8750-10-C-0237, Google Chrome University Research Program Awar

Partición y colación V

El mecanismo de la licitación regulado en el art. 2372 del Código Civil y Comercial debe interpretarse con amplitud, admitiendo que el co-partícipe ofrezca un monto superior al de su hijuela, en cuyo caso tendrá que compensar a lo coherederos abonándoles el saldo en dinero y al contado. La expresión del primer párrafo del art. 2372 del Código Civil y Comercial, en cuanto dispone “se le adjudique dentro de su hijuela”, no constituye un límite cuantitativo para la oferta del licitante.Facultad de Ciencias Jurídicas y Sociale

Partición y colación I

El derecho de los padres a realizar una partición de la herencia entre sus descendientes se impone y tiene preeminencia respecto de los supuestos de atribución preferencial configurados con anterioridad a la partición.Realizada la partición por el ascendiente, -por testamento o por donación-, los herederos no tienen derecho a contradecirla o cuestionarla invocando supuestos de atribución preferencial configurados con anterioridad a la formalización de la partición. Por el contrario, si las situaciones descriptas en la ley para habilitar el reclamo de una atribución preferencial en favor de alguno de los herederos surgen o adquieren firmeza o estabilidad luego de realizada la partición por el ascendiente en su testamento, el heredero beneficiado puede sí invocar la atribución preferencial en contra de la voluntad del ascendiente.Facultad de Ciencias Jurídicas y Sociale

Observing Ultra High Energy Cosmic Particles from Space: SEUSO, the Super Extreme Universe Space Observatory Mission

The experimental search for ultra high energy cosmic messengers, from $E\sim 10^{19}$ eV to beyond $E\sim 10^{20}$ eV, at the very end of the known energy spectrum, constitutes an extraordinary opportunity to explore a largely unknown aspect of our universe. Key scientific goals are the identification of the sources of ultra high energy particles, the measurement of their spectra and the study of galactic and local intergalactic magnetic fields. Ultra high energy particles might, also, carry evidence of unknown physics or of exotic particles relics of the early universe. To meet this challenge a significant increase in the integrated exposure is required. This implies a new class of experiments with larger acceptances and good understanding of the systematic uncertainties. Space based observatories can reach the instantaneous aperture and the integrated exposure necessary to systematically explore the ultra high energy universe. In this paper, after briefly summarising the science case of the mission, we describe the scientific goals and requirements of the SEUSO concept. We then introduce the SEUSO observational approach and describe the main instrument and mission features. We conclude discussing the expected performance of the mission

The importance of being little: MA-XRF on manuscripts on a Venetian island

The XRF scanning spectrometer developed in the framework of CHNet-INFN (Cultural Heritage Network - National Institute of Nuclear Physics), is specifically customised for cultural heritage applications, designed with a focus on having a lightweight scanner (weighing approximately 10 kg), easy to handle and thus easily transportable in two medium-sized boxes. The research presented here deals with the study of a set of choir books preserved in the Abbey of San Giorgio Maggiore on the homonymous island in Venice. Produced for the Abbey itself from the mid-15th century onwards, the manuscripts have never left the island, making the study of the materials of particular interest as they have undergone little or no modification over time. During their history in the Abbey, however, the volumes have been disassembled and reassembled in various ways, bringing complexity to the current cataloguing work. Thus, analytical investigations of the pigments and painting techniques might help identify the original arrangement of displaced leaves and provide evidence for the attribution of individual illuminations to certain artists. Thanks to its easy transportability, it was possible to take the scanner to the small island by means of the water-based Venetian public transport. Selected results are presented, derived from the high-quality MA-XRF maps obtained

Ultrathin Tropical Tropopause Clouds (UTTCs) : I. Cloud morphology and occurrence

Subvisible cirrus clouds (SVCs) may contribute to dehydration close to the tropical tropopause. The higher and colder SVCs and the larger their ice crystals, the more likely they represent the last efficient point of contact of the gas phase with the ice phase and, hence, the last dehydrating step, before the air enters the stratosphere. The first simultaneous in situ and remote sensing measurements of SVCs were taken during the APE-THESEO campaign in the western Indian ocean in February/March 1999. The observed clouds, termed Ultrathin Tropical Tropopause Clouds (UTTCs), belong to the geometrically and optically thinnest large-scale clouds in the Earth´s atmosphere. Individual UTTCs may exist for many hours as an only 200--300 m thick cloud layer just a few hundred meters below the tropical cold point tropopause, covering up to 105 km2. With temperatures as low as 181 K these clouds are prime representatives for defining the water mixing ratio of air entering the lower stratosphere