Roma Tre University

About: Roma Tre University is a education organization based out in Rome, Lazio, Italy. It is known for research contribution in the topics: Large Hadron Collider & Galaxy. The organization has 4434 authors who have published 15352 publications receiving 374888 citations. The organization is also known as: Universita degli Studi Roma Tre & RomaTre.

A review of experimental investigations and assessment methods for masonry arch bridges

Abstract: Masonry arch bridges constitute a significant proportion of European road and rail infrastructures. Most of them are well over 100 years old and are supporting traffic loads many times above those originally envisaged. The inherent variation in their constituent materials, the traditional design criteria and methods used for their construction, their deterioration over time caused by weathering processes and the development of other defects, significantly influence the mechanical response of these historic structures. A deep understanding on the numerous factors that affect the structural behaviour of masonry arch bridges and on the analysis methods to assess the life expectancy of such bridges and inform maintenance and strengthening strategies is essential. This paper provides a critical review of the experimental studies that have been carried out and of the assessment approaches that have been developed in the last three decades to these aims. The current knowledge is established and areas of ...

Extremotolerant rock inhabiting black fungi from Italian monumental sites

Abstract: A wide sampling for isolating highly destructive and extremotolerant black fungi was performed from Italian monuments in selected historical sites which include the “Cortile della Pigna”, Vatican Museum and the St Peter colonnade (Vatican City State), the monumental cemetery of Bonaria (Cagliari), and other monuments in the city of Cagliari. Thirty out of seventy-four strains isolated were identified basing on ITS Blastn comparison. Based on multilocus phylogeny and morphological data, one new genus and species Lithophila guttulata, five new species Knufia marmoricola, K. vaticanii, K. karalitana, K. mediterranea and Exophiala bonariae, order Chaetothyriales and one new genus and species, Saxophila tyrrhenica, and two new species Vermiconia calcicola and Devriesia sardiniae, order Capnodiales, were proposed. Ecological considerations are put forward.

Iron and nickel line properties in the X-ray-reflecting region of the Circinus galaxy

Abstract: We discuss the iron and nickel properties in the nuclear X-ray-reflecting region of the Circinus galaxy, studied with XMM-Newton. The main results are as follows. (i) From the depth of the Fe Ka edge, a value of A F e = 1.7 in number with respect to the cosmic value (as for Anders & Grevesse) is measured, if the (not directly visible) illuminating spectrum is assumed to be that measured by BeppoSAX. If the slope of the primary power law is left free to vary, a steeper spectrum and a lower iron abundance (about 1.2) are found. (ii) From the Ni to Fe Kα line flux ratio, a nickel-to-iron abundance ratio of 0.055-0.075 is found. (iii) The Fe Kβ/Kα flux ratio is slightly lower than expected, possibly due to a mild ionization of iron (which, however, cannot be much more ionized than x). (iv) The presence of the Fe Ka Compton shoulder, already discovered by Chandra, is confirmed, its relative flux implying Compton-thick matter. This further supports the identification of the reflecting region with the absorber.