Diagnostics,deterioration and provenance of stone materials from the Jefferson Page tomb (Non-Catholic Cemetery of Rome,Italy)     

Domenico Miriello  Marco Malagodi  Silvestro Antonio Ruffolo  Mauro Francesco La Russa  Gino Mirocle Crisci  Antonino Pezzino  Rita Galluccio  Donatella Barca  Elisa Marasco 《Environmental Earth Sciences》2010,60(4):829-836

The monumental tomb of Jefferson Page, an officer in the American Navy, was built in 1899 and is located in the Non-Catholic Cemetery of Rome (Italy). This study presents complementary diagnostic studies characterizing the stone of the tomb and the weathering and decay phenomena it has undergone. The monument is made of a single type of whitish marble, variously veined and often covered with black patinas. Petrographic, isotopic and LA-ICP-MS analyses attribute the marble to the Carrara district. SEM/EDS and microbiological analyses indicate that the black patinas are due to cyanobacterial autotrophic and fungin heterotrophic colonization. Fourier-transform infrared spectroscopy revealed the presence of organic material on some portions of the tomb, due to undocumented restoration carried out with a mixture of marble powder and a polyester resin.  相似文献   

A multidisciplinary approach to reveal the Sicily Climate and Environment over the last 20 000 years     

Alessandro Incarbona  Giuseppe Zarcone  Mauro Agate  Sergio Bonomo  Enrico Di Stefano  Federico Masini  Fabio Russo  Luca Sineo 《Central European Journal of Geosciences》2010,2(2):71-82

We present a thorough review of the knowledge on the climate and environment in Sicily over the last 20 000 years, taking into account results of several studies carried using terrestrial and marine records. We obtain a coherent framework of the most important changes succeeded in the island, even if some points need further investigation. All the reconstructions of surface temperatures of the seas and the air surrounding Sicily point out severe climatic conditions during the last glacial period. The steppe- and semisteppe-like vegetation pattern testifies, together with additional evidence from geochemical data of lacustrine evidence, markedly arid conditions. Fi-nally, significant episodes of sea level drop connected Sicily to the Italian Peninsula and favoured the dispersion of faunal elements from southern Italy. The transition between the last glacial and the Holocene was not characterized by a gradual warming but was punctuated by two abrupt suborbital climatic fluctuations: Bølling-Allerød (warm) and Younger Dryas (cold), as recognized in the sediments recovered close to the northern and southern coast of Sicily. A denser arboreal cover is possibly indicated by the occurrence of dormouse and Arvicola remains. Finally the sensitivity of Sicily to climate perturbations is demonstrated by the occurrence of repeated subtle climatic anomalies during the Holocene, including the Little Ice Age, also known from historical chronicles. Forests, woods and Mediterranean maquis developed in the early-middle Holocene. Thereafter was a general decline of arboreal vegetation, following a general aridification trend that seems to be a common feature in southern Europe and North Africa. Science Greek colonization (7^th century before Christ), the landscape was intensively modelled for agriculture and breeding, leading to a significant loss of vegetation cover.  相似文献   

Cylindrical isomorphic mapping applied to invariant manifold dynamics for Earth–Moon Missions     

Marco Giancotti  Mauro Pontani  Paolo Teofilatto 《Celestial Mechanics and Dynamical Astronomy》2014,120(3):249-268

Several families of periodic orbits exist in the context of the circular restricted three-body problem. This work studies orbital motion of a spacecraft among these periodic orbits in the Earth–Moon system, using the planar circular restricted three-body problem model. A new cylindrical representation of the spacecraft phase space (i.e., position and velocity) is described, and allows representing periodic orbits and the related invariant manifolds. In the proximity of the libration points, the manifolds form a four-fold surface, if the cylindrical coordinates are employed. Orbits departing from the Earth and transiting toward the Moon correspond to the trajectories located inside this four-fold surface. The isomorphic mapping under consideration is also useful for describing the topology of the invariant manifolds, which exhibit a complex geometrical stretch-and-folding behavior as the associated trajectories reach increasing distances from the libration orbit. Moreover, the cylindrical representation reveals extremely useful for detecting periodic orbits around the primaries and the libration points, as well as the possible existence of heteroclinic connections. These are asymptotic trajectories that are ideally traveled at zero-propellant cost. This circumstance implies the possibility of performing concretely a variety of complex Earth–Moon missions, by combining different types of trajectory arcs belonging to the manifolds. This work studies also the possible application of manifold dynamics to defining a suitable, convenient end-of-life strategy for spacecraft placed in any of the unstable orbits. The final disposal orbit is an externally confined trajectory, never approaching the Earth or the Moon, and can be entered by means of a single velocity impulse (of modest magnitude) along the right unstable manifold that emanates from the Lyapunov orbit at \(L_2\) .  相似文献   

Higher-order Gauss-Bonnet cosmology by Lagrange multipliers     

Salvatore Capozziello  Mauro Francaviglia  Andrey N. Makarenko 《Astrophysics and Space Science》2014,349(1):603-609

We study cosmological models derived from higher-order Gauss-Bonnet gravity F(R,G) by using the Lagrange multiplier approach without assuming the presence of additional fields with the exception of standard perfect fluid matter. The presence of Lagrange multipliers reduces the number of allowed solutions. We need to introduce compatibility conditions of the FRW equations, which impose strict restrictions on the metric or require the introduction of additional exotic matter. Several classes of F(R,G) models are generated and discussed.  相似文献   

The radiation environment in a low earth orbit:the case of BeppoSAX     

Riccardo Campana  Mauro Orlandini  Ettore Del Monte  Marco Feroci  Filippo Frontera 《Experimental Astronomy》2014,37(3):599-613

Low-inclination, low altitude Earth orbits (LEO) are of increasing importance for astrophysical satellites, due to their low background environment. Here, the South Atlantic Anomaly (SAA) is the region with the highest amount of radiation. We study the radiation environment in a LEO (500–600 km altitude, 4^° inclination) through the particle background measured by the Particle Monitor (PM) experiment onboard the BeppoSAX satellite, between 1996 and 2002. Using time series of particle count rates measured by PM we construct intensity maps and derive SAA passage times and fluences. The low-latitude SAA regions are found to have an intensity strongly decreasing with altitude and dependent on the magnetic rigidity. The SAA extent, westward drift and strength vs altitude is shown.  相似文献   

Magnetic parameters,trace elements,and multivariate statistical studies of river sediments from southeastern India: a case study from the Vellar River     

Marcos A. E. Chaparro  Mauro A. E. Chaparro  P. Rajkumar  V. Ramasamy  Ana M. Sinito 《Environmental Earth Sciences》2011,63(2):297-310

This contribution constitutes a new study using magnetic parameters and trace element determinations of pollutants in river sediments from the Tamil Nadu state. The Vellar River covers a total length of about 200 km and flows into the Bay of Bengal. Sediment samples were collected at different sediment depths (up to 90 cm) from 12 sites to investigate their magnetic properties (27 samples) and the contents of trace elements (21 out of 27 samples) along the river; as well as to perform magnetic studies for various grain size fractions (16 sub samples). The magnetic results of magnetic susceptibility and remanent magnetizations suggest that the magnetic signal of these sediments is controlled by ferrimagnetic minerals magnetite-like minerals and a minor contribution of antiferromagnetic carriers (such as hematite minerals). Detailed studies of selected samples showed a higher magnetic concentration in finer grain-sized fractions and a slightly different magnetic mineralogy. Magnetic concentration-dependent parameters evidenced high values, which, together with the background values, allowed us to identify magnetic enhancement at some sites. The Pearson correlation and multivariate statistical studies (Principal Component Analysis, Canonical Correlation Analysis) supported the relationship between the magnetic and chemical variables; in particular, magnetic susceptibility, anhysteretic and isothermal remanent magnetization are closely correlated to Co, Cr, Cu, Fe, V, Zn, and the pollution load index. In addition, Principal Coordinate Analysis and fuzzy C-means cluster analysis allowed us to make a classification and to perform a magnetic-chemical characterization of the data into four groups, thereby identifying critical (possibly polluted) sites from the Vellar River.  相似文献   

Vertical distribution of two sympatric labrid fishes in the Western Mediterranean and Eastern Atlantic rocky subtidal: local shore topography does matter     

Marco Milazzo  Angelo Palmeri  Jesús M. Falcón  Fabio Badalamenti  Jose A. Garcìa‐Charton  Mauro Sinopoli  Renato Chemello  Alberto Brito 《Marine Ecology》2011,32(4):521-531

Changes in the shore topography (e.g. slope) occur at a scale of hundreds of meters in several locations in the Lusitanian and the Mediterranean Sea provinces. We tested whether differences in the bottom inclination might affect the vertical distribution patterns of two sympatric coastal labrid fishes, the rainbow wrasse Coris julis and the ornate wrasse Thalassoma pavo. Visual censuses were used to determine the distribution and abundance of these labrid species in high (≥30°) and low (≤3°) slope rocky substrates covered by brown macroalgae and at two different depths (shallow, 4–7 m, and deep 14–20 m). Pectoral fin aspect ratio was used as an estimate of swimming performance to potentially explain the patterns observed. Despite the intrinsic biogeographical differences in the overall density of T. pavo and C. julis, on steep coasts the ornate wrasse dominated in shallow waters, whereas the two species coexisted both in shallow and deeper depths on gentle slope coasts. These distribution patterns were consistent across locations, and fin aspect ratio was not a good predictor of between‐habitat use for wrasses. We show that, under specific topographical conditions, the depth segregation pattern seems to be an interactive segregation (likely related to resource competition) rather than a result of selective segregation due to morphological differences in the pectoral fin. Significant ecological changes might occur in locations where the density of T. pavo has recently increased as a result of water warming.  相似文献   

A lacustrine record of early Holocene watershed events and vegetation history,Corvara in Badia,Dolomites (Italy)     

Lisa Borgatti  Cesare Ravazzi  Marta Donegana  Alessandro Corsini  Mauro Marchetti  Mauro Soldati 《第四纪科学杂志》2007,22(2):173-189

The early–middle Holocene lacustrine succession of Corvara in Badia (Italian Dolomites, 1521 m a.s.l.) records landslides and other watershed events before the onset of human pressure. The sensitivity of this archive to relate climate change, watershed processes and vegetation dynamics in the catchment has been explored through a stratigraphic study, including the analysis of sedimentological features, magnetic properties, palaeobotanical records and radiocarbon dating. A palaeolake existed between 10.1 k and 7 k cal. yr BP and was surrounded by a dense conifer forest. Long‐term forest dynamics driven by ecological processes and by climatic conditions favourable to upward forest expansion is recorded throughout the pollen record. Within the fine clastic sedimentation, distinct layers enriched in organic debris of terrestrial origin have been attributed to instant events produced by mass movements. Their age fits the chronology of large landslide events already known in the catchment, enabling correlation of the field evidence of landslides with the lacustrine record. Landslide frequency is controlled by geological and structural factors, but it is significantly modulated by the centennial–millennial climatic phases that characterise the Holocene in the Alps. The taphonomical properties of pollen and macroremains provided valuable insight on the mechanism of watershed processes. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

On helioseismic tests of basic physics     

J. Christensen-Dalsgaard  M. P. Di Mauro  H. Schlattl  A. Weiss 《Monthly notices of the Royal Astronomical Society》2005,356(2):587-595

An important goal of helioseismology is to provide information about the basic physics and parameters that determine the structure of the solar interior. Here we discuss the procedures applied in such analyses, using as an example attempts to obtain significant constraints on the value of Newton's gravitational constant G from helioseismology. The analysis is based on complete direct and inverse helioseismic analysis of a set of accurate observed acoustic frequencies. We confirm, as found by previous investigations based on different approaches, that the actual level of precision of the helioseismic inferences does not allow us to constrain G with a precision better than that which can be reached with direct experimental measurements. The conclusion emphasizes the importance in helioseismic inferences of considering not only the accuracy with which solar oscillations are measured, but also the effect of uncertainties in other aspects of the model computation and helioseismic analysis.  相似文献   

Coastal Ocean Forecasting Science supported by GODAE OceanView Coastal Oceans and Shelf Seas Task Team (COSS-TT)—Part II     

Cirano  Mauro  Charria  Guillaume  De Mey-Frémaux  Pierre  Kourafalou  Vassiliki H.  Stanev  Emil 《Ocean Dynamics》2021,71(6-7):779-783

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