421 research outputs found

    numerical analysis on the effect of focusing metasurfaces in energy harvesting applications

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    The aim of this thesis work is to describe Metasurfaces for Wireless Energy Harvesting (WEH) applications. The goal is to introduce newly conceptualized designs for focusing EM radiation into a predefined region with the aim of increasing the overall energy harvested by the system. The methodology behind the design of Metasurfaces for focusing applications will be described, with particular emphasis on PGMS (Phase-Shift Metasurfaces), together with their interaction with the freely propagating signals to obtain the desired ranging capability. Two models have been proposed, operating at 2.45 GHz, for increasing the received power and therefore enhancing the overall efficiency of a WEH link. The structures, completely passive, present a symmetric topology composed by concentric rings: the first one (3 rings model) allows to precisely focus the power at 20 cm of distance with 6.6 dB gain, while the second one (2 rings model) focuses the power at 2.5 cm with a gain 3 dB with less precision but proposing a compact design. The results have been obtained considering a link of 1 m where the transmitter and receiver are planar patches and it has been demonstrated how the presence of the metasurfaces increases the received power level, highlighting them as one of the most promising solutions for WEH applications

    Estetica e social trend di un’adolescenza senza filtri. Dinamiche di produzione e marketing in Euphoria.

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    Euphoria è una serie televisiva che ha ottenuto un successo di pubblico senza precedenti, conseguito svariati premi dalla critica ed influenzato il mondo della moda. Inoltre, la serie ha fatto avanzare il tipo di narrazione e rappresentazione televisiva proponendo contenuti sovversivi ed inediti. L’elaborato si concentra sul marketing presente sin dalla fase di sviluppo di Euphoria fino alla presentazione al pubblico. Il primo capitolo introduce il teen drama, genere di appartenenza della serie, e lo sviluppo delle tematiche che lo caratterizzano, per poi concentrarsi su Euphoria e i suoi elementi di innovazione e trasgressività. Il secondo capitolo analizza la serie nei suoi selling elements interni, ovvero le scelte dei reparti di produzione, soffermandosi sul loro valore di marketing. Il terzo capitolo, infine, tratta il digital marketing della serie focalizzandosi sulle diverse strategie adottate per la promozione

    Clastic vs. primary precipitated evaporites in the Messinian sicilian Basins

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    The Messinian stratigraphy of Sicily has a particular importance for the comprehension ofthe Messinian salinity crisis as its successions bear the greatest similarity with those of thedeep Mediterranean basins. Despite the large number of studies carried out in the last 30years, we believe that the true time and genetic relationships between the different evaporiticand non evaporitic rock bodies are still not well established. This is probably due to thelimited, partial view offered by the central Sicilian basin, despite its complete Messinianstratigraphic record.Clastic and chaotic evaporitic deposits emplaced by tectonically-driven small to largescaleresedimentation processes form an important part of the MSC record of Sicily in theBelice and Caltanissetta basins. Facies characteristics of clastic evaporites, the stratigraphicrelationships with the other Messinian deposits, their possible significance in the regionalgeological evolution and the implications at a Mediterranean scale will be discussed in thefield. Attention also will be paid to primary precipitated facies of Lower and UpperEvaporites.The main aim of this field trip is to visit and discuss, beside some of the classic localitiesof the Caltanissetta basin, other less known outcrops of western Sicily (Belice basin), inorder to have a more complete regional geological framework of the MSC events in Sicily.This will give the participants the opportunity to discuss many of the still open problemsconcerning the MSC. In this section we suggest some topics for discussion during the fieldtrip

    Physical activity intervention for elderly patients with reduced physical performance after acute coronary syndrome (HULK study): Rationale and design of a randomized clinical trial

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    Background: Reduced physical performance and impaired mobility are common in elderly patients after acute coronary syndrome (ACS) and they represent independent risk factors for disability, morbidity, hospital readmission and mortality. Regular physical exercise represents a means for improving functional capacity. Nevertheless, its clinical benefit has been less investigated in elderly patients in the early phase after ACS. The HULK trial aims to investigate the clinical benefit of an early, tailored low-cost physical activity intervention in comparison to standard of care in elderly ACS patients with reduced physical performance. Design: HULK is an investigator-initiated, prospective multicenter randomized controlled trial (NCT03021044). After successful management of the ACS acute phase and uneventful first 1 month, elderly (≥70 years) patients showing reduced physical performance are randomized (1:1 ratio) to either standard of care or physical activity intervention. Reduced physical performance is defined as a short physical performance battery (SPPB) score of 4-9. The early, tailored, low-cost physical intervention includes 4 sessions of physical activity with a supervisor and an home-based program of physical exercise. The chosen primary endpoint is the 6-month SPPB value. Secondary endpoints briefly include quality of life, on-treatment platelet reactivity, some laboratory data and clinical adverse events. To demonstrate an increase of at least one SPPB point in the experimental arm, a sample size of 226 patients is needed. Conclusions: The HULK study will test the hypothesis that an early, tailored low-cost physical activity intervention improves physical performance, quality of life, frailty status and outcome in elderly ACS patients with reduced physical performance

    The thick-bedded tail of turbidite thickness distribution as a proxy for flow confinement: examples from Tertiary basins of central and northern Apennines (Italy)

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    This study reviews the thickness statistics of non-channelized turbidites from four tertiary basins of Central-Northern Apennines (Italy), where bed geometry and sedimentary character have been previously assessed. Though very different in terms of size and, arguably, character of feeder system, these basins share a common stratigraphic evolution consisting in transition from an early ponded to a late unconfined setting of deposition. Based on comparison of thickness subsets from diverse locations and stratigraphic heights within the studied turbidite fills, this paper seeks to answer the following questions: i) how data collection procedures and field operational constraints (e.g. measure location, outcrop quality, use of thicknesses data from single vs. multiple correlative sections, stratigraphic thickness of the study interval) can affect statistics of sample data? ii) how depositional controls of confined vs. unconfined turbidite basins can result in different thickness-frequency distributions?; and iii) is there in thickness statistics a ‘flow confinement’ signature which can be used to distinguish between confined and unconfined turbidites? Results suggest that: i) best practices of data collection are crucial to a meaningful interpretation of sample data statistics, especially in presence of stratigraphic and spatial trends of turbidite bed thickness; ii) a systematic bias against cm-thick Tcd Bouma sequence turbidites exists in sample data, which can result in the low-end tail of empirical thickness-frequency distributions to depart significantly from the actual distribution of turbidite thickness; and iii) thickness statistics of beds starting with a basal Ta/Tb Bouma division bear a coherent relationship to the transition from ponded to unconfined depositional settings, consisting in reduction of variance and mean and, consequently, parameters, or even type, of best fit model distribution. This research highlights the role of flow stripping, sediment by-pass and bed geometry in altering the initial thickness distribution of ponded turbidites and suggests how fully ponded mini-basins represent the ideal setting for further research linking turbidite thickness statistics and frequency distribution of parent flow volumes

    A record of fossil shallow-water whale falls from Italy

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    Twenty-five Neogene-Quaternary whales hosted in Italian museum collections and their associated fauna were analysed for evidence of whale-fall community development in shallow-water settings. The degree of bone articulation, completeness of the skeleton and lithology of the embedding sediments were used to gather information on relative water depth, water energy, sedimentation rate and overall environmental predictability around the bones. Shark teeth and hard-shelled invertebrates with a necrophagous diet in close association with the bones were used as evidence of scavenging. Fossil bone bioerosion, microbially mediated cementation and other mollusc shells in the proximity of the remains informed on past biological activity around the bones. The results are consistent with the hypothesis that shallow-water whale falls differ from their deep-water counterparts. Taphonomic pathways are more variable on the shelf and whale carcasses may not go through all steps of the ecological succession as recognised in the deep sea. Whilst the mobile scavenger and the enrichment opportunistic stages are well represented, chemosynthetic taxa typical of the sulphophilic stage were recovered only in one instance. The presence of a generalist fauna among the suspension feeding bivalves and carnivorous gastropods, and the extreme rarity of chemosynthetic taxa, suggest that predatory pressure rules out whale-fall specialists from shallow shelf settings as in analogous cold seep and vent shallow-water communities. © 2014 The Lethaia Foundation

    Influence of flow containment and substrate entrainment upon sandy hybrid event beds containing a co-genetic mud-clast-rich division

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    Individual sandstone beds containing a co-genetic mud-clast-rich (MCR) division are being increasingly described from the distal reaches of many deep-water fan systems. These deposits, termed hybrid event beds, are considered to record a flow whose composition and rheology changed significantly to become increasingly more argillaceous (clay-rich), MCR and turbulence-suppressed during the deposition of a single event bed. Studies of confined systems, in which gravity flows were affected by confining sea-floor topography, have documented similar deposits recording turbulence suppression in proximity to confining sea-floor topography (e.g., basin margins). In new research from a confined, contained system from the Castagnola Basin of NW Italy, lateral transects of individual sandstone beds 5 km in extent show that individual sandstone beds contain a co-genetic MCR division which is often; 1) extensive across the basin rather than localised adjacent to confining topography; 2) exhibits rapid, significant and repeated variation in depositional character over short length scales (tens to hundreds of metres), specifically in terms of the thickness of co-genetic MCR divisions and the size and abundance of clasts contained within them; and 3) exhibits variation in depositional character over larger length scales (> 1 km) which is non-systematic in relation to palaeoflow direction or increasing proximity towards the counter slope of the downstream confining northern basin margin. A suite of factors within the Castagnola Basin is thought to have resulted in the deposition of these co-genetic MCR divisions whose thickness and distribution are less predictable in relation to confining sea-floor topography than those described from other confined uncontained settings. Specific factors include; 1) recent and voluminous entrainment of muddy substrate at seemingly random locations across the basin floor and their support and transport within a high sediment concentration gravity flow; and 2) containment (ponding) of gravity flows within a confined basin, which is thought to have established extensive and complex three dimensional flow dynamics across the basin following flow interaction with multiple basin margins. This research highlights the role of entrainment of muddy substrate and subsequent transport processes of muddy substrate for developing co-genetic MCR divisions, as well as the importance of understanding the degree of containment depositional systems experienced when considering the spatial distribution of depositional facies, and thus reservoir quality, in topographically complex settings

    Formation processes at a high resolution Middle Paleolithic site: Cueva Antón (Murcia, Spain)

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    Cueva Antón is a Middle Paleolithic rockshelter located in the valley of the River Mula (Murcia, Spain). The archeological investigation of the site, which began with salvage work in 1991, resumed in 2006 and is still ongoing, uncovered a succession spanning most of MIS 3 and MIS 4 (ca. 75e36 ka) and featuring a well preserved human occupation record. This paper presents the first information about site stratigraphy and site formation processes. Geoarcheological data collected in the field and through micromorphological observation show that the archeological succession at Cueva Antón is mainly composed of alluvial sediments, with thin intercalations of gravitational and slope material. The sedimentary characteristics of the alluvial succession are well preserved as the result of a rapid accumulation rate and the protective effect of the rockshelter. Several sedimentary facies produced by the shifting of distinct fluvial sub-environments (channel, bar and floodplain) are recognized. With the exception of a few units (II-u, a thin buried alluvial soil, and the archeologically richest units at the base of the succession), postdepositional modification is rare. The site was occupied within a framework of infrequent, short-term visits, resulting in a relatively low overall density of finds and the formation of well-defined archeological lenses that correspond to synchronous paleosurfaces preserving the spatial distribution of finds and features. This pattern explains the limited anthropogenic evidence observed in thin sections, even those from units where archeological excavation uncovered significant remains of human occupation
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