Inverse Compton X-rays from the radio galaxy 3C 219   总被引：1，自引：0，他引：1  

A. Comastri  G. Brunetti  D. Dallacasa  M. Bondi  M. Pedani  G. Setti 《Monthly notices of the Royal Astronomical Society》2003,340(4):L52-L56

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Anisotropic inverse Compton emission in the radio galaxy 3C 265   总被引：1，自引：0，他引：1  

M. Bondi  G. Brunetti  A. Comastri  G. Setti 《Monthly notices of the Royal Astronomical Society》2004,354(3):L43-L47

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Subsurface thermal conductivity assessment in Calabria (southern Italy): a regional case study     

Eloisa Di Sipio  Antonio Galgaro  Elisa Destro  Giordano Teza  Sergio Chiesa  Aurelio Giaretta  Adele Manzella 《Environmental Earth Sciences》2014,72(5):1383-1401

Determining the suitability of a local area at a regional or local scale for the geothermal application of low enthalpy systems requires the knowledge of rock thermal conductivity values to evaluate the possibility of low-enthalpy heat exchange. A digital cartographic tool is also needed to synthesize the thermal properties of the underground. This tool should be easily accessible and upgradeable and thus suitable for territorial planning and environmental control. In order to address these key issues, a methodological approach was developed within the framework of the national VIGOR Project, dedicated to evaluating the geothermal potential in southern Italy. In this paper the region of Calabria was selected as a case study. Around 70 samples that were representative of the main geological formations were collected from all over the area. Thermal property tests were carried out both in dry and wet conditions, using a thermal device in accordance with the modified transient plane source method. The thermal conductivity values were then compared with data from the international literature. In order to consider the influence of the entire stratigraphic sequence on the thermal conductivity parameters, a geostatistical analysis of the available lithostratigraphic data was performed using the MATLAB toolbox Modalstrata, specially developed for this purpose. A comprehensive geothermal subsurface characterization of Calabria was thus obtained.  相似文献   

Giant Radio Halos in Galaxy Clusters as Probes of Particle Acceleration in Turbulent Regions     

G. Brunetti 《Journal of Astrophysics and Astronomy》2011,32(4):437-445

Giant radio halos in galaxy clusters probe mechanisms of particle acceleration connected with cluster merger events. Shocks and turbulence are driven in the inter-galactic medium (IGM) during clusters mergers and may have a deep impact on the non-thermal properties of galaxy clusters. Models of turbulent (re)acceleration of relativistic particles allow good correspondence with present observations, from radio halos to γ-ray upper limits, although several aspects of this complex scenario still remain poorly understood.  相似文献   

Cooperation between bound waters and hydroxyls in controlling isotope-exchange rates     

Adele F. Panasci  J. Gregory McAlpin  C. André Ohlin  Shauna Christensen  James C. Fettinger  R. David Britt  James R. Rustad  William H. Casey 《Geochimica et cosmochimica acta》2012

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Characterization of Clay‐ and Silt‐Sized Fractions and Corresponding Humic Acids Along a Terra Rossa Soil Profile          下载免费PDF全文

Gennaro Brunetti  Giuseppe Natale Mezzapesa  Andreina Traversa  Eleonora Bonifacio  Karam Farrag  Nicola Senesi  Valeria D'Orazio 《洁净——土壤、空气、水》2016,44(10):1375-1384

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Were Pleistocene hippopotamuses exposed to climate‐driven body size changes?     

Paul P. A. Mazza  Adele Bertini 《Boreas: An International Journal of Quaternary Research》2013,42(1):194-209

This study proposes a working hypothesis that Mediterranean hippopotamuses, and perhaps European ones as well, reduced their size, sometimes even drastically, from the ‘Mid‐Pleistocene Revolution’ (MPR, c.1.2–0.5 Ma) to the Late Pleistocene. In contrast to the Early Pleistocene, during this time period glacial/interglacial cycling was dominated by a 100‐ka periodicity, with more extended glacial phases (up to 85 ka) alternating with shorter interglacial phases (up to 15 ka). These changes seem to have somehow affected the size of hippopotamuses. While relatively larger hippopotamuses have been found in warmer and somewhat more humid intervals, data seem to indicate that they might not have grown as large under less favourable conditions, namely during colder and comparatively drier times. This is a possible response to climate‐driven fluctuations in food availability, but Pleistocene habitat fragmentation may also have had an influence. Environmental break‐up during the late Quaternary led to the isolation of megafauna populations, which underwent modifications similar to those observed in insular mammals. Although the amount of remains available is still limited, it is nonetheless a fact that hippopotamuses changed their body size through time, normally becoming smaller. If the conclusions are confirmed as data continue to accumulate, hippopotamuses might cast doubt on the generality of Bergmann's rule.  相似文献   

The Connection between Radio Halos and Cluster Mergers and the Statistical Properties of the Radio Halo Population     

R. Cassano  G. Brunetti  T. Venturi 《Journal of Astrophysics and Astronomy》2011,32(4):519-527

We discuss the statistical properties of the radio halo population in galaxy clusters. Radio bi-modality is observed in galaxy clusters: a fraction of clusters host giant radio halos while a majority of clusters do not show evidence of diffuse cluster-scale radio emission. The radio bi-modality has a correspondence in terms of dynamical state of the hosting clusters showing that merging clusters host radio halos and follow the well-known radio-X-ray correlation, while more relaxed clusters do not host radio halos and populate a region well separated from that correlation. These evidences can be understood in the framework of a scenario where merger-driven turbulence re-accelerate the radio emitting electrons. We discuss the main statistical expectations of this scenario underlining the important role of the upcoming LOFAR surveys to test present models.  相似文献   

Schwertmannite stability in acidified coastal environments   总被引：1，自引：0，他引：1  

Richard N. Collins  Adele M. Jones  T. David Waite 《Geochimica et cosmochimica acta》2010,74(2):482-3451

A combination of analytical and field measurements has been used to probe the speciation and cycling of iron in coastal lowland acid sulfate soils. Iron K-edge EXAFS spectroscopy demonstrated that schwertmannite dominated (43-77%) secondary iron mineralization throughout the oxidized and acidified soil profile, while pyrite and illite were the major iron-bearing minerals in the reduced potential acid sulfate soil layers. Analyses of contemporary precipitates from shallow acid sulfate soil groundwaters indicated that 2-line ferrihydrite, in addition to schwertmannite, is presently controlling secondary Fe(III) mineralization. Although aqueous pH values and concentrations of Fe(II) were seasonally high, no evidence was obtained for the Fe(II)-catalyzed crystallization of either mineral to goethite. The results of this study indicate that: (a) schwertmannite is likely to persist in coastal lowland acid sulfate soils on a much longer time-scale than predicted by laboratory experiments; (b) this mineral is less reactive in these types of soils due to surface-site coverage by components such as silicate and possibly, to a lesser extent, natural organic matter and phosphate and; (c) active water table management to promote oxic/anoxic cycles around the Fe(II)-Fe(III) redox couple, or reflooding of these soils, will be ineffective in promoting the Fe(II)-catalyzed transformation of either schwertmannite or 2-line ferrihydrite to crystalline iron oxyhydroxides.  相似文献   

Alfvénic reacceleration of relativistic particles in galaxy clusters in the presence of secondary electrons and positrons     

G. Brunetti  P. Blasi 《Monthly notices of the Royal Astronomical Society》2005,363(4):1173-1187

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