Time filter

Source Type

Persico R.,Institute for Archaeological and Monumental Heritage | Sala J.,3d Radar AS
2011 6th International Workshop on Advanced Ground Penetrating Radar, IWAGPR 2011 | Year: 2011

In this paper, we will focus on some possibilities but also some problems related to the application of a 2D linear inversion algorithm (based on the Born approximation) on large scale data. In particular, the problem of the limited size of the investigation domain is dealt with, and it will be shown that it represents not only a computational problem but can also have some relevance with regard to the quality of the overall achieved image. Experimental results related to both a two dimensional inversion and a two dimensional migration based procedure will be shown. © 2011 IEEE.

Lettieri M.,Institute for Archaeological and Monumental Heritage | Lionetto F.,University of Salento | Frigione M.,University of Salento | Prezzi L.,SAFE Marine Nanotechnologies | Mascia L.,Loughborough University
Polymer Engineering and Science | Year: 2011

Experimental organic-inorganic hybrid systems, based on silane functionalized difunctional and trifunctional epoxy resins and an alkoxysilane precursor mixture, containing small amounts of ammonium molybdate, are evaluated for potential use as adhesives cured at ambient temperatures. The precursor resin mixtures are found to exhibit a large increase in viscosity with a pseudoplastic behavior. Scanning electron microscopy (SEM) analysis shows the existence of siloxane domains with nanometric dimensions, except for the presence of microscopic molybdate particles. By monitoring the evolution of the glass transition temperature (Tg) during curing, varying the thickness of the specimens between 0.2 and 4.5 mm, it is found that the organic-inorganic hybrids display a significant increase in the final T g over the parent unmodified epoxy resins, particularly in thin specimens and when ammonium molybdate is added. Small-angle X-ray scattering (SAXS) spectra show that the dimensions and typographic features of thick and thin specimens are similar, both containing an agglomeration of primary particles of 5-6 nm. © 2010 Society of Plastics Engineers.

Gennarelli G.,National Research Council Italy | Catapano I.,National Research Council Italy | Soldovieri F.,National Research Council Italy | Persico R.,Institute for Archaeological and Monumental Heritage
IEEE Transactions on Antennas and Propagation | Year: 2015

This communication is concerned with the performance achievable within a 3-D inverse scattering approach in relationship with the measurement configuration. The problem is undertaken under the Born approximation, and three configurations are considered, namely a multimonostatic, a single view/multistatic and a multiview/multistatic, all of them in the multifrequency framework. The analysis is worked out with the tools of the diffraction tomography and of the singular value decomposition of the relevant operator. Tomographic reconstructions based on full-wave synthetic data are shown. © 2015 IEEE.

Persico R.,Institute for Archaeological and Monumental Heritage | Sala J.,3d Radar AS
IEEE Geoscience and Remote Sensing Letters | Year: 2014

We focus on the choice of the investigation domains for a 2-D linear inversion algorithm based on the Born approximation. The application of an inversion algorithm to a wide B-scan requires the subdivision of the data into several observation domains and the partition of the buried scenario into different investigation domains, and this can be done in many ways, which raises the problem of examining the well advisedness of the adopted choice. In particular, here, we will propose the possibility of a double sequence of investigation domains. The results will also be compared with a migration algorithm. © 2004-2012 IEEE.

Calia A.,Institute for Archaeological and Monumental Heritage | Lettieri M.,Institute for Archaeological and Monumental Heritage | Quarta G.,Institute for Archaeological and Monumental Heritage
Applied Clay Science | Year: 2011

Clay minerals often occur in the finishing layers covering the surface of historic and architectural artefacts. They may come from ochres intentionally applied or from atmospheric dust naturally deposited. In the first case the finishes could testify to treatments applied for the stone conservation and/or aesthetic purposes, whose study is of great interest in conservation activities.In this paper we report on the application of microdestructive analytical techniques in order to identify the presence and the origin of clay minerals found on the surfaces of several historic buildings located in the Apulia region (Southern Italy). Optical and SEM observations, along with EDS microanalyses, and FTIR analyses were performed. The microdestructive character of these techniques made it possible to carry out the analyses on the same specimen, thus reducing the sampling. XRD analyses were also performed to confirm the presence of clay minerals. The complementary analytical findings were helpful in most cases in establishing the real origin of the clay minerals; the detection of organic materials arising from man-made treatments allowed to identify clays as pigments. However, in some cases the uncertainty remained between ochre, intentionally employed, and soil-dust deposition. © 2010 Elsevier B.V.

Discover hidden collaborations