Biometric and Genetic Analysis of the Marine Rissoid Rissoa auriscalpium (Gastropoda, Prosobranchia) and its Ecological Implications     

Rita  Colognola  Pietro  Masturzo  Giovanni Fulvio  Russo  Mlchele  Scardi  Daniele  Vlnci Eugenio  Fresi 《Marine Ecology》1986,7(3):265-285

Abstract. Two forms of Rissoa auriscalpium were found in Posidonia oceanica beds around the Island of Ischia (Gulf of Naples). In order to investigate their taxonomical value and to quantify the discriminating features found, the radular, conchometric, genetic, and ecological features of the two forms were analyzed. Ecological observations showed that the distribution of the two forms is strongly correlated with hydrodynamic factors.  相似文献   

Formation and export of water masses produced in Arctic shelf polynyas -- process studies of oceanic convection     

Backhaus  Jan O.; Fohrmann  Hermann; Kampf  Jochen; Rubino  Angelo 《ICES Journal of Marine Science》1997,54(3):366-382

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Giant sediment drifts on the continental rise west of the Antarctic Peninsula     

Michele Rebesco  Robert D. Larter  Angelo Camerlenghi  Peter F. Barker 《Geo-Marine Letters》1996,16(2):65-75

Multichannel seismic reflection profiles from the continental rise west of the Antarctic Peninsula between 63° and 69°S show the growth of eight very large mound-shaped sedimentary bodies. MCS profiles and long-range side-scan sonar (GLORIA) images show the sea floor between mounds is traversed by channels originating in a dendritic pattern near the base of the continental slope. The mounds are interpreted as sediment drifts, constructed mainly from the fine-grained components of turbidity currents originating on the continental slope, entrained in a nepheloid layer within the ambient southwesterly bottom currents and redeposited downcurrent.  相似文献   

Representation of Multiaquifer Well Effects in Three-Dimensional Ground-Water Flow Simulation     

Gordon D. Bennett  Angelo L. Kontis  Steven P. Larson 《Ground water》1982,20(3):334-341

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Thermal surveys on the Lake Garda by infrared equipments     

Dr. Michele Colacino  Prof. Maurizio Giorgi  Dr. Angelo Guerrini  Dr. Franco Vivona 《Meteorology and Atmospheric Physics》1976,25(2):159-170

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The Upper Miocene magmatism of the Island of Elba (Central Italy): compositional characteristics,petrogenesis and implications for the origin of the Tuscany Magmatic Province     

Giampiero Poli  Angelo Peccerillo 《Mineralogy and Petrology》2016,110(4):421-445

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Improved assessment of biodegradation extent and prediction of petroleum quality     

Rouven Elias  Andrea Vieth  Angelo Riva  Brian Horsfield  Heinz Wilkes 《Organic Geochemistry》2007,38(12):2111-2130

Biodegradation of crude oil causes volumetrically important compositional changes, which lead to significant deterioration in quality, in particular during the early stages of alteration. To better understand these effects we focussed on a detailed assessment of light to moderate levels of alteration. We investigated a suite of 40 crude oil samples from five different petroleum systems to evaluate the extent of alteration occurring in reservoirs. Based on a comprehensive geochemical characterization, five individual crude oil sequences were defined, where compositional variability is mainly due to microbial activity in the reservoir. In particular, samples from the Gullfaks field (offshore Norway) and from a petroleum system offshore Angola illustrate that conventional molecular biodegradation parameters, such as the Pr/n-C₁₇ and Ph/n-C₁₈ alkane ratios are not suitable for defining the extent of biodegradation in petroleum reservoirs. Here, we suggest a new molecular biodegradation parameter, the degradative loss, that can be used to quantify depletion in individual crude oil constituents. The approach allows improved assessment of the extent of biodegradation in crude oil samples by means of the mean degradative loss. It is demonstrated that crude oil quality, as assessed from API gravity, can be predicted directly from the molecular composition of crude oils. Our data clearly indicate that the degradation patterns of light hydrocarbons and n-alkanes differ in different petroleum systems. This suggests that microbial communities are different and therefore generate different molecular degradation patterns which have to be evaluated individually for each system.  相似文献   

Genesis of lightning potentials     

Angelo Montani 《Pure and Applied Geophysics》1972,97(1):234-240

Summary The generation of very high atmospheric potentials is ascribed to the sudden separation of a cloud, or portion of it, into an upper and lower section, substantially, of opposite polarities. Said abrupt cut being, the mechanical effect produced by local wind gusts. The related mathematical analysis shows how theoretically infinite voltage spikes may be generated as forced electrical transients when a cloud separates into two sections.  相似文献   

Magnetic stratigraphy of Vesuvius products. I. 1631 lavas     

Paola R. Gialanella  Alberto Incoronato  Filippo Russo  Giuseppina Nigro 《Journal of Volcanology and Geothermal Research》1993,58(1-4)

An extensive palaeomagnetic study has been undertaken to provide further elements leading to a better assessment of the volcanic history of the Vesuvius. This work refers to lavas for which the date of emplacement have recently been questioned; i.e. either during the period 968–1037 or in 1631. From 7 sites, 97 sun-orientated specimens have been collected. The dominant magnetic carrier for all sites consists of magnetite on the basis of an analysis of IRM acquisition. The linearity analysis carried out on at least 6 specimens per site subjected to PAFD has indicated the presence of single- and multi-component magnetizations. The within-site mean directions of 5 sites are close to each other suggesting that lavas from these sites can be ascribed to the same volcanic event. The remaining 2 sites can also be referred to this event on ground of stratigraphical considerations. The plotting of the between-site mean directions of the previously mentioned 5 sites on the Vesuvius secular variation curve suggests that the lavas from these sites could not be emplaced during the period 968–1037 but some hundred years later than 1301. The stratigraphic and historic dating of deposits and a building, respectively, at one of the 2 remaining sites allows to conclude that all the investigated flows had to be emplaced during the 1631 event. Therefore, this event was characterized not only by explosive activity but by an important effusive phase as well.  相似文献   

The role of site effects in the comparison between code provisions and the near field strong motion of the Emilia 2012 earthquakes   总被引：1，自引：1，他引：0  

Maria Rosaria Gallipoli  Leonardo Chiauzzi  Tony Alfredo Stabile  Marco Mucciarelli  Angelo Masi  Carmine Lizza  Luigi Vignola 《Bulletin of Earthquake Engineering》2014,12(5):2211-2230

A damaging seismic sequence hit a wide area mainly located in the Emilia-Romagna region (Northern Italy) during 2012 with several events of local magnitude \(\hbox {M}_\mathrm{l} \ge 5\) , among which the \(\hbox {M}_\mathrm{l}\) 5.9 May 20 and the \(\hbox {M}_\mathrm{l}\) 5.8 May 29 were the main events. Thanks to the presence of a permanent accelerometric station very close to the epicentre and to the temporary installations performed in the aftermath of the first shock, a large number of strong motion recordings are available, on the basis of which, we compared the recorded signals with the values provided by the current Italian seismic regulations, and we observed several differences with respect to horizontal components when the simplified approach for site conditions (based on Vs30 classes) is used. On the contrary, when using the more accurate approach based on the local seismic response, we generally obtain a much better agreement, at least in the frequency range corresponding to a quarter wavelength comparable with the depth of the available subsoil data. Some unresolved questions still remain, such as the low frequency behaviour ( \(<\) 1 Hz) that could be due either to complex propagation at depth larger than the one presently investigated or to near source effects, and the behaviour of vertical spectra whose recorded/code difference is too large to be explained with the information currently available.  相似文献