On-line recognition of supernova neutrino bursts in the LVD     

N.Yu. Agafonova  M. Aglietta  P. Antonioli  G. Bari  A. Bonardi  V.V. Boyarkin  G. Bruno  W. Fulgione  P. Galeotti  M. Garbini  P.L. Ghia  P. Giusti  F. Gomez  E. Kemp  V.V. Kuznetsov  V.A. Kuznetsov  A.S. Malguin  H. Menghetti  A. Pesci  R. Persiani  I.A. Pless  A. Porta  V.G. Ryasny  O.G. Ryazhskaya  O. Saavedra  G. Sartorelli  M. Selvi  C. Vigorito  L. Votano  V.F. Yakushev  G.T. Zatsepin  A. Zichichi 《Astroparticle Physics》2008,28(6):516-522

In this paper we show the capabilities of the Large Volume Detector (INFN Gran Sasso National Laboratory) to identify a neutrino burst associated with a supernova explosion, in the absence of an “external trigger”, e.g., an optical observation. We describe how the detector trigger and event selection have been optimized for this purpose, and we detail the algorithm used for the on-line burst recognition. The on-line sensitivity of the detector is defined and discussed in terms of supernova distance and intensity at the source.  相似文献   

The Ñuagapua alluvial fan sequence: Early and Late Holocene human-induced changes in the Bolivian Chaco?     

Mauro Coltorti  Jacopo Della Fazia 《Proceedings of the Geologists' Association. Geologists' Association》2010,121(2):218-126

The Quebrada Ñaguapua alluvial fan provides a record of changes that have affected the Bolivian Chaco during the Holocene. The 4th oldest Unit, possibly related to the last glaciation, is restricted to the fan apex; it was deeply dissected during the Early Holocene, with three other units emplaced within the resultant incision. Sandy sediments characterise Unit 1 and 3 while Unit 2 is a forest soil that marks a period of stability. The oldest Unit 1 was deposited just before 6900 years BP. It contains artefacts that represent the earliest evidence of human occupation and suggests that deposition was perhaps induced by deforestation. Anthropogenic deforestation is evident at the base of Unit 3, which contains a wooden plank (140 years BP), charcoal, ash and charred tree-trunks. Some trunks have been burnt in situ while others survived the fire and are still growing, although their roots emanate from Unit 2. Although, similar events slightly to the north have been attributed to climatic changes, the delay in soil erosion in closely spaced areas could be plausibly attributed to human-induced changes. Megafaunal remains in Unit 1 represent the last occurrence of megafauna, including horse, in South America. The faunal association is anomalous because of the concurrent presence of aquatic, forest and open-environment species. We suggest that the last migrated from the southern part of Continent, where ecologic conditions allowed their survival in the Early Holocene, after the widespread clearing of the natural forest and shortly prior to the extinction of the Magafauna.  相似文献   

Composition and spatial distribution of infauna in a river estuary affected by fishpond effluents     

Galope-Bacaltos DG  San Diego-McGlone ML 《Marine pollution bulletin》2002,44(8):816-819

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The quantitative analysis of OH in vesuvianite: a polarized FTIR and SIMS study     

Fabio Bellatreccia  Giancarlo Della Ventura  Luisa Ottolini  Eugen Libowitzky  Anton Beran 《Physics and Chemistry of Minerals》2005,32(1):65-76

A well-characterized suite of vesuvianite samples from the volcanic ejecta (skarn or syenites) from Latium (Italy) was studied by single-crystal, polarized radiation, Fourier-transform infrared (FTIR) spectroscopy and secondary-ion mass-spectrometry (SIMS). OH-stretching FTIR spectra consist of a rather well-defined triplet of broad bands at higher-frequency (3,700–3,300 cm^–1) and a very broad composite absorption below 3,300 cm^–1. Measurements with E//c or Ec show that all bands are strongly polarized with maximum absorption for E//c. They are in agreement with previous band assignments (Groat et al. Can Mineral 33:609, 1995) to the two O(11)–H(1) and O(10)–H(2) groups in the structure. Pleochroic measurements with changing direction of the E vector of the incident radiation show that the orientation of the O(11)–H(1) dipole is OHc~35°, in excellent agreement with the neutron data of Lager et al. (Can Mineral 37:763, 1999). A SIMS-based calibration curve at ~10% rel. accuracy has been worked out and used as reference for the quantitative analysis of H₂O in vesuvianite by FTIR. Based on previous SIMS results for silicate minerals (Ottolini and Hawthorne in J Anal At Spectrom 16:1266, 2001; Ottolini et al. in Am Mineral 87:1477, 2002) the SiO₂ and FeO content of the matrix were assumed as the major factors to be considered at a first approximation in the selection of the standards for H. The lack of vesuvianite standards for quantitative SIMS analysis of H₂O has been here overcome by selecting low-silica elbaite crystals (Ottolini et al. in Am Mineral 87:1477, 2002). The resulting integrated molar absorption FTIR coefficient for vesuvianite is _i=100.000±2.000 l mol^–1 cm^–2. SIMS data for Li, B, F, Sr, Y, Be, Ba REE, U and Th are also provided in the paper.  相似文献   

GIS-ILA:THE GIS FOR ITALIAN LOGISTICS IN ANTARCTICA   总被引：2，自引：0，他引：2  

Luigi Rossi  A.B.Della Rocca  R.Cervellati  D.Manco  R.Chiocchini  F.Chiocchini  A.Cimbelli 《地球空间信息科学学报》2001,4(2):32-39

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Catastrophic floods as a possible cause of organic matter accumulation giving rise to coal, Paraná Basin, Brazil     

Romana Begossi  Jorge Carlos Della Fvera 《International Journal of Coal Geology》2002,52(1-4)

Gondwana coals of the Rio Bonito Formation (Paraná Basin) in Southern Brazil have generally large ash yields, so they could be better called coaly siltstones than coal. In addition, hummocky cross stratification (HCS) was found in several coal beds of the Rio Bonito Formation throughout the basin. In this formation, the frequent and close relationship between facies involving rocks generated by subaqueous gravity flows (diamictites) and coal itself provides an excellent depositional model based on resedimentary processes acting during deposition, as well as a stratigraphic rearrangement of the present units.In the State of Rio Grande do Sul (southern part of Paraná Basin), coals are actually prodelta deposits related to delta-front diamictite and conglomeratic sandstone with sigmoidal bedding. Coal-forming organic sediments would come from trees plucked by the floods, as indicated by the wood logs floating in the diamictite, and reworking of previous peat accumulations. Every coal layer is covered generally by paleosoil siltstones, which represent colonization at the top of the catastrophic flood deposit, ending a sedimentary cycle.In case of Brazilian coal settings, several authors recognized deltas (fan deltas or braid deltas). Here is particularly considered the general environment as a salted interior sea (lago mare, Hsü et al. sense).The present study will refer to three important lithostratigraphic units in the Carboniferous–Early Triassic cycle: the Itararé Group, the Rio Bonito Formation, and the Palermo Formation.Although the preferential mode of occurrence of HCS in shallow marine environments indicates a genesis attributed to storm action, other causes, such as catastrophic flooding, have been advanced. Mutti et al. [Mem. Sci. Geol. 48 (1996) 233] described flood-dominated deltaic systems with thick conglomerate, sandstone, and pelitic deposits, derived from small- to medium-scale fluvial systems and mountain-bordered drainage basins adjacent to the sea. In such settings, seaward sediment flow can increase dramatically when weather conditions can supply water in such amounts to produce catastrophic floods. Thick and laterally extensive sandstone lobes with HCS are the fundamental depositional elements of fan deltas and other river-dominated delta systems.Diamictites and coal together could be a result from Jökullhlaups—an Icelandic term for glacial outburst flood—in case of catastrophic floods coming from a melting mountain glacier, similar to the Columbia River Valley Scablands (15,000 BP) and in modern Iceland examples.  相似文献   

Cummingtonite in the amphibolites of the South-Alpine basement complex (upper Lake Como region,Italy): Its relationships with hornblende     

A. Mottana  R. Bocchio  R. Crespi  L. De Capitani  G. Liborio  G. Della Ventura 《Mineralogy and Petrology》1994,51(1):67-84

Summary Cummingtonite and hornblende occur together in metamorphosed basic rocks interlayered with lower-amphibolite facies sillimanite-muscovite-bearing schists and gneisses in the upper Lake Como region, South-Alpine basement complex of the Alps. Textural, chemical and spectroscopic studies indicate that they do not represent equilibrium pairs, but that hornblende was overgrown by cummingtonite during a late stage of either temperature increase or, more likely, of isothermal pressure release, by a continuous reaction which also produced the reverse zoning of plagioclase.

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Cummingtonit in den Amphiboliten des südalpinen Grundgebirges (oberes Comosee-Gebiet, Italien): seine Beziehungen mit Hornblende

Zusammenfassung Im Gebiet des oberen Como-Sees, im südalpinen Basement-Komplex, kommen Cummingtonit und Hornblende zusammen in metamorphen, basischen Gesteinen mit Zwischenlagen von Sillimanit-Muskovit-führenden Schiefern und Gneisen der unteren Amphibolit-Fazies vor. Untersuchung der Texturen, der chemischen Zusammensetzung und Infrarot-Spektroskopie zeigen, daß diese nicht Gleichgewichts-Paare darstellen, sondern daß Hornblende während eines späten Stadiums, entweder bei zunehmender Temperatur, oder eher während isothermalen Druck-Nachlasses durch eine kontinuierliche Reaktion von Cummingtonit überwachsen wurde, die auch für die reverse Zonierung der Plagioklase verantwortlich ist.

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With 5 Figures  相似文献   

Comparative crystal chemistry of spinels from some suites of ultramafic rocks     

Dr. F. Princivallel  Prof. A. Della Giusta  Dr. S. Carbonin 《Mineralogy and Petrology》1989,40(2):117-126

Summary Microprobe analyses and X-ray crystal structure refinement data of Mg-Fe-Al-Cr spinels from different environments are compared. The investigated crystals represent both restitic and recrystallized spinels from an Alpine peridotitic massif, and restitic spinels from four suites of ultramafic xenoliths. Within each suite the crystals represent different steps of an increasing melting process, which causes a strong increase in Cr³⁺ and a moderate increase in Fe²⁺, with depletion of Al³⁺ and Mg²⁺. Within each suite, in spite of relevant bulk chemistry changes, the ratio of the octahedral to tetrahedral coordination distances, and consequently the oxygen positional parameterx, are kept constant. Conversely,x may differ in suites with similar bulk chemistry, mainly due to different Mg-Al ordering between octahedral and tetrahedral sites. This suggests that thex parameter is strongly affected by physical environment, and that consequently, within the range of the investigated compositions, it could be used as a marker.

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Vergleich der Kristallchemie von Spinellen aus einigen Suiten von ultramafischen Gesteinen

Zusammenfassung EMS-Analyse und röntgenograhsch verfeinerte Kristallstrukturen von Mg-Fe-Al-Cr Spinellen aus verschiedenen petrologischen Situationen wurden verglichen. Unter den untersuchten Kristallen befinden sich sowohl restitische und rekristallisierte Spinelle aus alpinen Peridotiten, als auch restitische Spinelle aus vier Suiten von ultramafischen Xenolithen. Die Kristalle in jeder Suite gehören zu verschiedenen Stufen eines Schmelzprozesses, der ein starkes Anwachsen der Cr³⁺ - und ein mäßiges Anwachsen der Fe²⁺- Konzentration bei gleichzeitiger Verminderung des Al³⁺ - und Mg²⁺-Gehaltes, verursacht. Jede Suite zeigt, trotz bedeutender chemischer Veränderungen, ein feststehendes Verhältnis von oktaedrischen zu tetraedrischen Polyederdimensionen, weshalb der Sauerstoffparameter x unveränderlich bleibt. Jedoch sehen wir, daß sich diex von den Spinellen zweier verschiedener Suiten mit ähnlichem Chernismus unterscheiden, was auf die unterschiedliche Mg-Al- Anordnung in oktaedrischen und tetraedrischen Positionen zurückzuführen ist. Dies läßt vermuten, daß der Parameterx sehr stark von der petrogenetischen Situation abhängig ist, was bedeutet, daß er als Anhaltspunkt zum Verständnis der physikalischen Entstehungsbedingungen verwendet werden kann.

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With 3 Figures  相似文献   

Thermal modelling of the Larderello geothermal field (Tuscany,Italy)     

Bruno Della Vedova  Claudio Vecellio  Stefano Bellani  Umberta Tinivella 《International Journal of Earth Sciences》2008,97(2):317-332

We present a 3-D thermal model of the Larderello geothermal field (Tuscany) to evaluate (1) the extent and contribution of the heat transfer mechanisms (conduction vs. convection) at the intermediate-upper crust levels, (2) the variability of the heat and mass fluxes entering from below and (3) the crucial role of the formation permeability. The model, composed by three main layers, considers the upper 10 km of the crust to better constrain the simulations with experimental data from borehole, fluid inclusion studies and hypocentral distributions. Several sets of simulations were carried out with different bottom boundary temperatures and different formation permeabilities for the two deeper layers. The results indicate that the present temperature (T) and pressure distributions in the Larderello field require deep reservoir rocks with higher permeability than the overlying capping units and underlying intermediate crust. Permeability values of 1 mDarcy for the reservoir rocks are enough to allow fluid convection, if the temperature at 10 km depth is as high as 500 ± 50°C. The presence of localized zones with formation permeability 50–100 times higher than the surrounding rocks strongly favours the migration of over-pressurized fluids, which episodically break through the overburden, feeding the presently exploited geothermal fields.  相似文献   

A numerical model for the simulation of debris flow triggering,propagation and arrest     

D’Aniello  Andrea  Cozzolino  Luca  Cimorelli  Luigi  Della Morte  Renata  Pianese  Domenico 《Natural Hazards》2015,75(2):1403-1433

Natural Hazards - In this paper, it is described the development and the assessment of a 1D numerical procedure for the simulation of debris flow phenomena. The procedure focuses on: (1) the...  相似文献