Shaking table tests of an arch-pillars system and design of strengthening by the use of tie-rods     

C. Calderini  S. Lagomarsino  M. Rossi  G. De Canio  M. L. Mongelli  I. Roselli 《Bulletin of Earthquake Engineering》2015,13(1):279-297

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Early Holocene transgressive palaeogeography in the Po coastal plain (northern Italy)          下载免费PDF全文

Luigi Bruno  Kevin M. Bohacs  Bruno Campo  Tina M. Drexler  Veronica Rossi  Irene Sammartino  Daniele Scarponi  Wan Hong  Alessandro Amorosi 《Sedimentology》2017,64(7):1792-1816

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Sensitivity analysis of CDOM spectral slope in artificial and natural samples: an application in the central eastern Mediterranean Basin     

Luca Bracchini  Antonio Tognazzi  Arduino Massimo Dattilo  Franco Decembrini  Claudio Rossi  Steven Arthur Loiselle 《Aquatic Sciences - Research Across Boundaries》2010,72(4):485-498

In the past two decades, optical properties of chromophoric dissolved organic matter (CDOM) in marine environments have been extensively studied. Many of these studies report CDOM properties for the offshore environment where this complex mixture of optically active compounds is strongly diluted. Nevertheless, autochthonous and allochthonous sources have been identified and sinks related to photodegradation and bacterial activity have been demonstrated. The calculation of the spectral slope of the CDOM absorption curve has been proven to be useful and is often reported. However, a rigorous uncertainty analysis of the slope calculation is rarely reported. In this paper, we propose a method to evaluate the uncertainty of CDOM spectral slope calculated between 270 and 400 nm, using both naturally sampled and artificial solutions. We use these results to study the ultra-oligotrophic waters of the Mediterranean Sea (central eastern basin), where little is known about CDOM spatial distribution. We show that dilutions of both artificial and natural samples produce a Gaussian distribution of spectral slopes, indicating that consistent values may be determined, with a typical uncertainty of ±0.0004 nm⁻¹ when absorption at 300 nm was greater then 0.1 m⁻¹ (0.1 m pathlength). Comparing the distribution of spectral slopes from central eastern basin samples to a Gaussian distribution, we show differences between measurements that were significantly different. These values allow us to distinguish possible sources (algal derived CDOM), sinks (e.g. photo-bleaching) at different depths. We propose a subdivision of CDOM compounds into refractory and semilabile/refractory pools and evaluate the CDOM spectral slope of algal derived CDOM released at or near deep chlorophyll maximum.  相似文献   

Degradation and Detoxification of Chlorophenols in Continuous‐Flow Fixed‐Bed Aerobic Reactors     

Alfredo Gallego  Virginia L. Gemini  Susana L. Rossi  Carlos E. Gómez  Gustavo D. Bulus Rossini  Sonia E. Korol 《洁净——土壤、空气、水》2011,39(8):774-780

An indigenous bacterial strain of Delftia sp. capable of degrading 2,4‐dicholorophenol and an indigenous bacterial community that degrades 2,4,6‐trichlorophenol (TCP) were employed to inoculate continuous down‐flow fixed‐bed reactors. Continuous‐reactors were constructed from PVC employing hollow PVC cylinders as support material. Synthetic wastewater was prepared by dissolving the corresponding chlorophenol in non‐sterile groundwater. Biodegradation was evaluated by spectrophotometry, chloride release, GC, and microbial growth. Detoxification was evaluated by using Daphnia magna as test organism. Delftia sp. was able to remove an average of 95.6% of DCP. Efficiency in terms of chemical oxygen demand (COD) was of 88.9%. The indigenous bacterial community that degrades TCP reached an average efficiency of 96.5 and 91.6% in terms of compound and COD removal, respectively. In both cases stoichiometric removal of chloride and detoxification was achieved. When synthetic wastewater feed was cut off for 7 days, both reactors showed a fast recovery after inflow restarting, reaching average outlet concentration values within 36 h. The promising behavior of the microorganisms and the low cost of the reactors tested allow us to suggest their possible application to remediation processes.  相似文献   

Extension tardi-orogénique et formation des bassins intracontinentaux: le bassin stéphanien des Cévennes     

Pascal Allemand  Jean-Marc Lardeaux  Gilles Dromart  Magali Ader 《Geodinamica Acta》2013,26(2):70-80

Résumé

Le bassin carbonifère des Cévennes, voisin du décrochement sénestre de Villefort, a été étudié en intégrant les données sédimentologiques, les données structurales du socle et du remplissage, ainsi que les données de la pétrologie métamorphique du socle. Le remplissage du bassin est contrôlé par des failles subméridiennes induisant une subsidence localisée en début d’ouverture. Cette subsidence devient plus régionale en fin d’histoire. Un grenat mangane- sifère est associé aux minéraux du faciès schistes verts, des blastes d’andalousite recoupent l’ensemble. Cette association minéralogique indique un gradient de température de 50°C/km. Ce gradient est semblable au gradient estimé dans le bassin sur la matière organique. La schistosité porte trois familles de linéation : 1- une famille à biotite-chlorite-quartz, orientée N45 ± 20° et associée à la mise en place des nappes cévenoles; 2- une famille à minéraux phylliteux dont l’orientation est située autour de N90 et associée à l’ouverture du bassin; 3- une famille à minéraux phylliteux orientée NO horizontale sur des plans de schistosité redressés près de la faille de Villefort. La schistosité régionale est affectée par des plis asymétriques, des bandes de cisaillement et des zones cata- clasées, le tout ayant une cinématique en faille normale vers l’Est. Les relations entre ces différentes structures suggèrent un continuum de déformation depuis des niveaux ductiles jusqu’à des niveaux fragiles. Le remplissage du bassin est affecté par des décrochements parallèles à la faille de Ville- fort. Le bassin des Cévennes s’est donc ouvert dans un contexte extensif est-ouest sur une croûte épaissie. La région a ensuite été reprise par des décrochements nord-sud dont celui de Villefort.  相似文献   

Recovery of the macrozoobenthic community after severe dystrophic crises in a Mediterranean coastal Lagoon (Orbetello, Italy)   总被引：9，自引：0，他引：9  

Lardicci C  Como S  Corti S  Rossi F 《Marine pollution bulletin》2001,42(3):202-214

The Orbetello lagoon, one of the largest Western Mediterranean lagoons, was affected by high algal blooms and severe anoxic crises in 1992 and 1993, with fish mortality throughout most of the lagoon and a drastic reduction of benthic species. Many measures were undertaken between 1994 and 1996 to remove the severe eutrophication of this lagoon. Such measures included harvesting of the floating seaweed biomass, removal of all wastewater and sea channel enlargement by dredging activity. The aim of the present research was to study the macrozoobenthic assemblage in 1999 and to compare it with previous research in order to assess the recovery of the lagoon. A total of 106 taxa and 45,175 individuals were collected in three areas (sea inlets, western and eastern lagoon) having different organic matter loading during winter and summer. The results of multivariate and correlation analyses indicated that trophic status and its seasonal dynamics were crucial in determining species distribution among the different areas. Moreover, comparison of the macrozoobenthic structure between winter 1995 and 1999 showed differences in species composition and structural parameters in the western and eastern lagoon, where a clear recovery of benthic assemblages was observed in 1999. However, the dominance of opportunistic species in most of the lagoon and the decrease in some structural parameters during summer suggested that this basin still presented signs of disturbance in 1999, six years after the last extended anoxic crises and even after completion of the restoration measures carried out in the environment. It was hypothesized that a secondary disturbance, sustained by a high seasonal release of nutrients from the sediments, could create considerable deviations from the expected improvement in benthic conditions.  相似文献   

The SWAP EUV Imaging Telescope Part I: Instrument Overview and Pre-Flight Testing     

D. B. Seaton  D. Berghmans  B. Nicula  J.-P. Halain  A. De Groof  T. Thibert  D. S. Bloomfield  C. L. Raftery  P. T. Gallagher  F. Auchère  J.-M. Defise  E. D’Huys  J.-H. Lecat  E. Mazy  P. Rochus  L. Rossi  U. Schühle  V. Slemzin  M. S. Yalim  J. Zender 《Solar physics》2013,286(1):43-65

The Sun Watcher with Active Pixels and Image Processing (SWAP) is an EUV solar telescope onboard ESA’s Project for Onboard Autonomy 2 (PROBA2) mission launched on 2 November 2009. SWAP has a spectral bandpass centered on 17.4 nm and provides images of the low solar corona over a 54×54 arcmin field-of-view with 3.2 arcsec pixels and an imaging cadence of about two minutes. SWAP is designed to monitor all space-weather-relevant events and features in the low solar corona. Given the limited resources of the PROBA2 microsatellite, the SWAP telescope is designed with various innovative technologies, including an off-axis optical design and a CMOS–APS detector. This article provides reference documentation for users of the SWAP image data.  相似文献   

Interactive Visualization to Advance Earthquake Simulation     

Louise H. Kellogg  Gerald W. Bawden  Tony Bernardin  Magali Billen  Eric Cowgill  Bernd Hamann  Margarete Jadamec  Oliver Kreylos  Oliver Staadt  Dawn Sumner 《Pure and Applied Geophysics》2008,165(3-4):621-633

The geological sciences are challenged to manage and interpret increasing volumes of data as observations and simulations increase in size and complexity. For example, simulations of earthquake-related processes typically generate complex, time-varying data sets in two or more dimensions. To facilitate interpretation and analysis of these data sets, evaluate the underlying models, and to drive future calculations, we have developed methods of interactive visualization with a special focus on using immersive virtual reality (VR) environments to interact with models of Earth’s surface and interior. Virtual mapping tools allow virtual “field studies” in inaccessible regions. Interactive tools allow us to manipulate shapes in order to construct models of geological features for geodynamic models, while feature extraction tools support quantitative measurement of structures that emerge from numerical simulation or field observations, thereby enabling us to improve our interpretation of the dynamical processes that drive earthquakes. VR has traditionally been used primarily as a presentation tool, albeit with active navigation through data. Reaping the full intellectual benefits of immersive VR as a tool for scientific analysis requires building on the method’s strengths, that is, using both 3D perception and interaction with observed or simulated data. This approach also takes advantage of the specialized skills of geological scientists who are trained to interpret, the often limited, geological and geophysical data available from field observations.  相似文献   

In situ heavy metals (copper, lead and cadmium) in different plankton compartments and suspended particulate matter in two coupled Mediterranean coastal ecosystems (Toulon Bay, France)     

Rossi N  Jamet JL 《Marine pollution bulletin》2008,56(11):1862-1870

We monitored the concentrations of copper, lead and cadmium in seawater, in suspended particulate matter (SPM) and in bacteria, phyto- and zooplankton communities separated from abiogenic particles, over a one year cycle in two coupled Mediterranean coastal ecosystems (Little Bay (LiB) and Large Bay (LaB)). Metals were present in seawater in the order Cu > Pb > Cd in both bays and showed important variations within the same month than among months. In LiB, their concentrations were between 0.62 and 2.82 μg Cu l⁻¹, 0.16 and 19 μg Pb l⁻¹ and 0.007 and 0.14 μg Cd l⁻¹, respectively, whereas in LaB, they were between 0.23 and 2.11 μg Cu l⁻¹, 0.09 and 0.76 μg Pb l⁻¹ and not detected and 0.65 μg Cd l⁻¹. SPM play an important role on metal adsorption, especially for copper. Bioaccumulation factors showed that bacteria and phytoplankton accumulate metals whereas zooplankton tends to biodiminish them in the plankton food web.  相似文献   

Gully head modelling: A Mediterranean badland case study          下载免费PDF全文

Dino Torri  Jean Poesen  Mauro Rossi  Valerio Amici  Daniele Spennacchi  Cati Cremer 《地球表面变化过程与地形》2018,43(12):2547-2561

Predicting the location of gully heads in various environments is an important step towards predicting gully erosion rates. So far, field data collection and modelling of topographic thresholds for gully head development has mainly focused on gullies that formed in forested areas, rangelands, pastures and cropland. Such information for gullies in badlands however is very scarce. Therefore, this paper aims to extend the database on gully head topographical thresholds through data collection in a badland area and to improve the prediction of gully heads forming at sites with a very low erosion resistance value. For this, we chose a badland site located in central Italy that is characterized by biancana forms and both active and dormant gullies. The definition of the conditions under which present‐day gully heads developed allowed a better modelling of the gully head threshold equation, with modification of a previous model and the exemplification of how to use the updated model. The model shows that the resistance to gully head retreat depends on slope gradient and drainage area at gully heads, land use at the moment of gully development (as numerically expressed using parameters derived from the Runoff Curve Number method), surface rock fragment cover, presence of joints, pipes, and factors/processes affecting detachment rate. This study attempted to better understand environmental conditions that control the development of gully heads in badlands through a combination of field data collection of gully heads, an analysis of land use changes over 10 centuries, focusing on the period 1820–2005, and land use management through repeat photography and a critical examination of historical documents. © 2018 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.  相似文献