465 research outputs found

    Hydrogeological characterization of peculiar Apenninic springs

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    Abstract. In the northern Apennines of Italy, springs are quite widespread over the slopes. Due to the outcropping of low-permeability geologic units, they are generally characterized by low-yield capacities and high discharge variability during the hydrologic year. In addition, low-flow periods (discharge lower than 1 Ls-1) reflect rainfall and snowmelt distribution and generally occur in summer seasons. These features strongly condition the management for water-supply purposes, making it particularly complex. The "Mulino delle Vene" springs (420 m a.s.l., Reggio Emilia Province, Italy) are one of the largest in the Apennines for mean annual discharge and dynamic storage and are considered as the main water resource in the area. They flow out from several joints and fractures at the bottom of an arenite rock mass outcrop in the vicinity of the Tresinaro River. To date, these springs have not yet been exploited, as the knowledge about the hydrogeological characteristics of the aquifer and their hydrological behaviour is not fully achieved. This study aims to describe the recharge processes and to define the hydrogeological boundaries of the aquifer. It is based on river and spring discharge monitoring and groundwater balance assessment carried out during the period 2012–2013. Results confirm the effectiveness of the approach, as it allowed the total aliquot of discharge of the springs to be assessed. Moreover, by comparing the observed discharge volume with the one calculated with the groundwater balance, the aquifer has been identified with the arenite slab (mean altitude of 580 m a.s.l.), extended about 5.5 km2 and located 1 km west of the monitored springs

    Expansion of the core business of traditional media companies in Spain through SVOD services

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    The strategic importance of the internet for television became evident in the early 2000s, even destabilizing its very concept and finally resulting in convergence towards a profound transformation of the sector. The introduction of global over-the-top (OTT) media services into local markets has led to strategic changes in multimedia groups. This study considers the subscription video-on-demand (SVOD) services of Atresmedia and Mediaset España, the two main traditional media organizations in Spain that form a duopoly in the country’s commercial television sector, with the aim of understanding and evaluating their positioning strategy in this market and the results obtained through the diversification of their core business. Based on an analysis of their content, price, and promotion policies and the results in terms of subscriptions and revenues, slight differences emerge regarding the strategy and scope of these two groups in their own environment in the sector. They compete for customers to achieve growth in the audiovisual market while seeking to retain a cross-media, multiplatform audience, as well as expand their core business of commercial linear television against a background of a reduction of advertising spend on television and the expected increase of hybrid financing models

    Estimating mass-wasting processes in active earth slides – earth flows with time-series of High-Resolution DEMs from photogrammetry and airborne LiDAR

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    Abstract. This paper deals with the use of time-series of High-Resolution Digital Elevation Models (HR DEMs) obtained from photogrammetry and airborne LiDAR coupled with aerial photos, to analyse the magnitude of recently reactivated large scale earth slides – earth flows located in the northern Apennines of Italy. The landslides underwent complete reactivation between 2001 and 2006, causing civil protection emergencies. With the final aim to support hazard assessment and the planning of mitigation measures, high-resolution DEMs are used to identify, quantify and visualize depletion and accumulation in the slope resulting from the reactivation of the mass movements. This information allows to quantify mass wasting, i.e. the amount of landslide material that is wasted during reactivation events due to stream erosion along the slope and at its bottom, resulting in sediment discharge into the local fluvial system, and to assess the total volumetric magnitude of the events. By quantifying and visualising elevation changes at the slope scale, results are also a valuable support for the comprehension of geomorphological processes acting behind the evolution of the analysed landslides

    Groundwater processes in a complex landslide, northern Apennines, Italy

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    The hydrogeological characteristics of rototranslationalslides in flysch are complex, due to the inherentanisotropy and heterogeneity of rock masses and related deposits.The paper deals with the hydrogeological characterizationof a reactivated roto-translational slide affecting Cretaceousflysch rocks, located in the northern Apennines ofItaly. Continuous monitoring of groundwater levels, in-situpermeability and pumping tests, hydrochemical and physicalanalyses and Uranine tracers were the adopted prospectingmethods.In this research hydrological monitoring and investigationare summarized in order to define a hydrogeological conceptualmodel of the landslide source area. Results showed thattwo overlaying hydrogeological units exist at the slope scale:the first is unconfined, but highly compartmentalized, andhosted in the fractured and dismembered rock slide body.The second is confined and lays in the undisturbed flyschbelow the sliding surface. The groundwater level in theconfined hydrogeological unit is twenty meters higher thanthe groundwater level in the uppermost one. Moreover, thegroundwater chemistry characterization revealed a rising ofdeep fluids in the landslide area

    Noncompaction Cardiomyopathy, Sick Sinus Disease, and Aortic Dilatation: Too Much for a Single Diagnosis?

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    HCN4 mutations have been reported in association with sick sinus syndrome. A more complex phenotype, including noncompaction cardiomyopathy and aortic dilatation, has recently emerged. We report 3 family members with the pathogenic p.Gly482Arg variant, emphasizing the importance of considering HCN4 mutations when this combination of features is encountered in clinical practice. (Level of Difficulty: Advanced.

    Acquisizione di rumore sismico nell'Appennino Reggiano Modenese 11-15 aprile 2006

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    Tra l’11 e il 15 aprile 2006 è stata condotta una campagna di acquisizione di rumore sismico in alcuni siti in frana dell’Appennino Settentrionale. Lo scopo dell’esperimento è quello di stimare gli effetti di sito su corpi franosi tipici dell’Appennino Modenese e Reggiano, nonché di studiare il comportamento delle frane quando sono soggette ad eventi sismici. Le registrazioni di rumore sono state effettuate con stazioni equipaggiate con sensori a corto periodo a tre componenti. Per la stima dell’amplificazione locale è stata scelta una serie di siti caratterizzati da litologie diverse. Inoltre, in siti omogenei e ben studiati dal punto di vista strutturale, sono state effettuate delle misure di rumore in configurazione di array per la stima di un modello di velocità superficiale, allo scopo di confrontare i risultati sperimentali con le funzioni di trasferimento teoriche. La durata delle registrazione non è stata inferiore ad un’ora per ogni sito. Le misure sono state effettuate sulle frane di Ca’ Lita (MO), Cavola (RE) e La Lezza Nuova (RE). Tutte e tre sono frane da colata, caratterizzate dalla presenza in superficie di strati di argille, e sono state studiate dal punto di vista strutturale, tra l’altro attraverso pozzi di sondaggio ed esperimenti di sismica attiva

    Development of a multiphysics model for the study of fuel compressibility effects in the Molten Salt Fast Reactor

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    Compressible fluid dynamics is of great practical interest in many industrial applications, ranging from chemistry to aeronautical industry, and to nuclear field as well. At the same time, modelling and simulation of compressible flows is a very complex task, requiring the development of specific approaches, in order to describe the effect of pressure on the fluid velocity field. Compressibility effects become even more important in the study of two-phase flows, due to the presence of a gaseous phase. In addition, compressibility is also expected to have a significant impact on other physics, such as chemical or nuclear reactions occurring in the mixture. In this perspective, multiphysics represents a useful approach to address this complex problem, providing a way to catch all the different physics that come into play as well as the coupling between them. In this work, a multiphysics model is developed for the analysis of the generation IV Molten Salt Fast Reactor (MSFR), with a specific focus on the compressibility effects of the fluid that acts as fuel in the reactor. The fuel mixture compressibility is expected to have an important effect on the system dynamics, especially in very rapid super-prompt-critical transients. In addition, the presence of a helium bubbling system used for online fission product removal could modify the fuel mixture compressibility, further affecting the system transient behaviour. Therefore, the MSFR represents an application of concrete interest, inherent to the analysis of compressibility effects and to the development of suitable modelling approaches. An OpenFOAM solver is developed to handle the fuel compressibility, the presence of gas bubbles in the reactor as well as the coupling between the system neutronics and fluid dynamics. The outcomes of this analysis point out that the fuel compressibility plays a crucial role in the evolution of fast transients, introducing delays in the expansion feedbacks that strongly affect the system dynamics. Moreover, it is found that the gas bubbles significantly alter the fuel compressibility, yielding even larger differences compared to the incompressible approximation usually adopted in the current MSFR solvers

    Back analysis of the 2014 San Leo Landslide using combined terrestrial laser scanning and 3D distinct element modelling

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    This is the author accepted manuscript. The final version is available from Springer Verlag via http://dx.doi.org/10.1007/s00603-015-0763-5© 2015 Springer-Verlag Wien Landslides of the lateral spreading type, involving brittle geological units overlying ductile terrains, are a common occurrence in the sandstone and limestone plateaux of the northern Apennines of Italy. The edges of these plateaux are often the location of rapid landslide phenomena, such as rock slides, rock falls and topples. In this paper, we present a back analysis of a recent landslide (February 2014), involving the north-eastern sector of the San Leo rock slab (northern Apennines, Emilia-Romagna Region) which is a representative example of this type of phenomena. The aquifer hosted in the fractured slab, due to its relatively higher secondary permeability in comparison to the lower clayey units leads to the development of perennial and ephemeral springs at the contact between the two units. The related piping erosion phenomena, together with slope processes in the clay-shales have led to the progressive undermining of the slab, eventually predisposing large-scale landslides. Stability analyses were conducted coupling terrestrial laser scanning (TLS) and distinct element methods (DEMs). TLS point clouds were analysed to determine the pre- and post-failure geometry, the extension of the detachment area and the joint network characteristics. The block dimensions in the landslide deposit were mapped and used to infer the spacing of the discontinuities for insertion into the numerical model. Three-dimensional distinct element simulations were conducted, with and without undermining of the rock slab. The analyses allowed an assessment of the role of the undermining, together with the presence of an almost vertical joint set, striking sub-parallel to the cliff orientation, on the development of the slope instability processes. Based on the TLS and on the numerical simulation results, an interpretation of the landslide mechanism is proposed

    The structure of radiatively induced Lorentz and CPT violation in QED at finite temperature

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    We obtain the induced Lorentz- and CPT-violating term in QED at finite temperature using imaginary-time formalism and dimensional regularization. Its form resembles a Chern-Simons-like structure, but, unexpectedly, it does not depend on the temporal component of the fixed bμb_\mu constant vector that is coupled to the axial current. Nevertheless Ward identities are respected and its coefficient vanishes at T=0, consistently with previous computations with the same regularization procedure, and it is a non-trivial function of temperature. We argue that at finite TT a Chern-Simons-like Lorentz- and CPT-violating term is generically present, the value of its coefficient being unambiguously determined up to a T−T-independent constant, related to the zero-temperature renormalization conditions.Comment: 15 pages, Latex, 1 figure in eps-format (included
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