Geological setting and geochemical signatures of the mafic rocks from the Intra-Pontide Suture Zone: implications for the geodynamic reconstruction of the Mesozoic Neotethys     

Kaan Sayit  Michele Marroni  M. Cemal Göncüoglu  Luca Pandolfi  Alessandro Ellero  Giuseppe Ottria  Chiara Frassi 《International Journal of Earth Sciences》2016,105(1):39-64

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Empirical evaluation of peak ground velocity and displacement as a function of elastic spectral ordinates for design          下载免费PDF全文

Roberto Paolucci  Chiara Smerzini 《地震工程与结构动力学》2018,47(1):245-255

In the framework of the revision of Part 1 of Eurocode 8, this study aims at developing new empirical correlations to compute peak values of ground velocity (PGV) and displacement (PGD) as a function of elastic spectral ordinates for design. At variance with the expressions for PGV and PGD currently adopted in the Eurocode 8, based solely on the peak ground acceleration (PGA), in this paper reference is made to spectral ordinates of the short and intermediate period range, namely S_s, which is the constant acceleration spectral ordinate, and S₁, which is the spectral ordinate at 1 s. On the one hand, a relationship between PGV and the product (S_s?S₁) was found based on the regression analysis on a high‐quality strong‐motion dataset. On the other hand, the PGD was estimated by extrapolating to long periods the constant displacement branch of the elastic response spectrum, introducing a correlation between the corner period T_D and S₁. For this purpose, results of a long period probabilistic seismic hazard assessment study for Italy, encompassing low to high seismicity areas, were considered. Furthermore, verification of the proposed relationship against strong‐motion records was carried out, and differences justified in terms of the concept of uniform hazard spectrum.  相似文献   

Evaluation of out‐of‐plane seismic performance of column‐to‐column precast concrete cladding panels in one‐storey industrial buildings          下载免费PDF全文

Andrea Belleri  Fabrizio Cornali  Chiara Passoni  Alessandra Marini  Paolo Riva 《地震工程与结构动力学》2018,47(2):397-417

Recent earthquakes in Italy (L'Aquila 2009 and Emilia 2012) highlighted the vulnerability of precast cladding panels, typically associated with a connection system not designed to account for displacement and rotation compatibility between the panels and the supporting structure. Experimental investigations were performed in the past to investigate the in‐plane performance of cladding panels and design recommendations have been made accordingly; however, in the case of out‐of‐plane seismic loads, the load demand is commonly evaluated in the design practice by means of formulations for nonstructural components. This paper summarizes the results obtained from parametric analyses conducted to estimate the out‐of‐plane load demand in column‐to‐column cladding panels typical of one‐storey commercial and industrial buildings. Empirical equations suitable for both new and existing panels are proposed and compared with the design equations given in Eurocode 8 and ASCE 7. The paper also considers the effects of the development of plastic hinges at the column base and of the roof flexibility on the load demand in panel‐to‐column connections. The roof flexibility may generate the torsion of the panels; consequently, an analytical procedure to account for such effects is proposed. Finally, general design recommendations are made.  相似文献   

From cylindrical to non‐cylindrical foreland basin: Pliocene–Pleistocene evolution of the Po Plain–Northern Adriatic basin (Italy)     

Chiara Amadori  Giovanni Toscani  Andrea Di Giulio  Francesco Emanuele Maesano  Chiara D&#x;Ambrogi  Manlio Ghielmi  Roberto Fantoni 《Basin Research》2019,31(5):991-1015

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MASTER: A multiple aspect view on trajectories   总被引：1，自引：0，他引：1  

Ronaldo dos Santos Mello  Vania Bogorny  Luis Otavio Alvares  Luiz Henrique Zambom Santana  Carlos Andres Ferrero  Angelo Augusto Frozza  Geomar Andre Schreiner  Chiara Renso 《Transactions in GIS》2019,23(4):805-822

For many years trajectory data have been treated as sequences of space‐time points or stops and moves. However, with the explosion of the Internet of Things and the flood of big data generated on the Internet, such as weather channels and social network interactions, which can be used to enrich mobility data, trajectories become more and more complex, with multiple and heterogeneous data dimensions. The main challenge is how to integrate all this information with trajectories. In this article we introduce a new concept of trajectory, called multiple aspect trajectory, propose a robust conceptual and logical data model that supports a vast range of applications, and, differently from state‐of‐the‐art methods, we propose a storage solution for efficient multiple aspect trajectory queries. The main strength of our data model is the combination of simplicity and expressive power to represent heterogeneous aspects, ranging from simple labels to complex objects. We evaluate the proposed model in a tourism scenario and compare its query performance against the state‐of‐the‐art spatio‐temporal database SECONDO extension for symbolic trajectories.  相似文献   

Finding moving flock patterns among pedestrians through collective coherence     

Monica Wachowicz  Rebecca Ong  Chiara Renso  Mirco Nanni 《International journal of geographical information science》2013,27(11):1849-1864

Tracking technologies are able to provide high-resolution movement data that can advance research in different fields, such as tourism management. In this specific field, developing methods to extract moving flock patterns from such data are particularly relevant to enable us to improve our knowledge of the nature of recreational use interactions, which is crucial for a good management of attractions and for designing sustainable development policies. However, ‘flocking’ has been usually associated with the form of collective movement of a large group of birds, fish, insects and certain mammals as well. Very few research efforts have been devoted in finding flock patterns associated with pedestrian movement. In this work, we propose a moving flock pattern definition and a corresponding extraction algorithm based on the notion of collective coherence. We use the term collective coherence to refer to the spatial closeness over some time duration with a minimum number of members. Furthermore, we evaluate the proposed algorithm by applying it to two different pedestrian movement datasets, which have been gathered from visitors of two recreational parks. The results show that the algorithm is capable of extracting moving flock patterns, disqualifying the patterns with flock members that remain stationary in a common place during the considered time interval.  相似文献   

Ecology of active rock glaciers and surrounding landforms: climate,soil, plants and arthropods     

Duccio Tampucci  Mauro Gobbi  Giuseppe Marano  Patrizia Boracchi  Giacomo Boffa  Francesco Ballarin  Paolo Pantini  Roberto Seppi  Chiara Compostella  Marco Caccianiga 《Boreas: An International Journal of Quaternary Research》2017,46(2):185-198

Active rock glaciers are periglacial landforms consisting of coarse debris with interstitial ice or ice‐core. Recent studies showed that such landforms are able to support plant and arthropod life and could act as warm‐stage refugia for cold‐adapted species due to their microclimate features and thermal inertia. However, integrated research comparing active rock glaciers with surrounding landforms to outline their ecological peculiarities is still scarce. We analysed the abiotic (ground surface temperature and humidity, soil physical and chemical parameters) and biotic (plant and arthropod communities) features of two Alpine active rock glaciers with contrasting lithology (silicate and carbonate), and compared them with the surrounding iceless landforms as reference sites (stable slopes and active scree slopes). Our data show remarkable differences between stable slopes and unstable landforms as a whole, while few differences occur between active scree slopes and active rock glaciers: such landforms show similar soil features but different ground surface temperatures (lower on active rock glaciers) and different occurrence of cold‐adapted species (more frequent/abundant on active rock glaciers). Both plant and arthropod species distributions depend mainly on the geographical context as a function of soil pH and on the contrast between stable slopes and unstable landforms as a function of the coarse debris fraction and organic matter content, while the few differences between active scree slopes and active rock glaciers can probably be attributed to microclimate. The role of active rock glaciers as potential warm‐stage refugia for cold‐adapted species is supported by our data; however, at least in the European Alps, their role in this may be less important than that of debris‐covered glaciers, which are able to host cold‐adapted species even below the climatic tree line.  相似文献   

Radial periodic perturbations of the Kepler problem     

Alessandro Fonda  Anna Chiara Gallo 《Celestial Mechanics and Dynamical Astronomy》2017,129(3):257-268

We consider radial periodic perturbations of a central force field and prove the existence of rotating periodic solutions, whose orbits are nearly circular. The proof is mainly based on the Implicit Function Theorem, and it permits to handle some small perturbations involving the velocity, as well. Our results apply, in particular, to the classical Kepler problem.  相似文献   

Comparison of 3D, 2D and 1D numerical approaches to predict long period earthquake ground motion in the Gubbio plain, Central Italy     

Chiara Smerzini  Roberto Paolucci  Marco Stupazzini 《Bulletin of Earthquake Engineering》2011,9(6):2007-2029

In this work we studied the performance of different numerical approaches to simulate the large amplifications of long period earthquake ground motion within the Gubbio plain, a closed-shape intra-mountain alluvial basin of extensional tectonic origin in Central Italy, observed during the Umbria-Marche 1997 seismic sequence. Particularly, referring to the Sep 26 1997 M_w6.0 mainshock, we considered the following numerical approximations: (a) 3D model, including a kinematic model of the extended seismic source, a layered crustal structure, and the basin itself with a simplified homogeneous velocity profile; (b) 2D model of a longitudinal and transversal cross-section of the basin, subject to vertical and oblique incidence of plane waves with time dependence at bedrock obtained by the 3D simulations; (c) 1D model. 3D and 2D numerical simulations were carried out using the spectral element code GeoELSE, exploiting in 3D its implementation in parallel computer architectures. 3D numerical simulations were successful to predict the observed large amplification of ground motion at periods beyond about 1 s, due to the prominent onset of surface waves originated at the southern edge of the basin and propagating northwards. More specifically, the difference of 3D vs 2D results is remarkable, since the latter ones fail to approach such large amplification levels, even when an oblique incidence of plane waves is considered.  相似文献   

Determination of chemical weathering rates from U series nuclides in soils and weathering profiles: Principles,applications and limitations     

François Chabaux  Lin Ma  Peter Stille  Eric Pelt  Mathieu Granet  Damien Lemarchand  Raphael di Chiara Roupert  Susan L. Brantley 《Applied Geochemistry》2011

The development of U-series nuclides for investigating weathering processes has been significantly stimulated by the analytical improvement made over the last decades in measuring the ²³⁸U series with intermediate half-lives (i.e., ²³⁴U–²³⁰Th–²²⁶Ra). It is proposed in this paper to present principles and methods that are now being developed to determine weathering rates from the study of U-series nuclides in soils and weathering profiles. Mathematical approaches, developed to calculate such rates, are based on some implicit assumptions that are also presented and must be kept in mind if one wants to correctly interpret the obtained ages.  相似文献