4,934 research outputs found

    Public investment, convergence and productivity growth in European regions

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    This paper estimates an augmented growth model to analyse the contribution of public investment to productivity growth for European regions. The empirical model accounts for the accumulation of public capital, the stock of infrastructure and the creation of knowledge by the government sector, alongside other growth determinants, as institutions, education, and business R&D. Convergence dynamics are also explored. Data include 273 NUTS2 European regions from 27 countries from 1999 to 2018. The empirical evidence presented suggests that public investment is positively associated with productivity growth and complementarities with business investment are in place. Furthermore, returns on both types of investments are larger in the regions of the Southern periphery, flagging policy space for further public and private productive spending. No significant effect is found for the stock of infrastructure. Public R&D has an indirect impact on productivity growth through the mediating effect of business R&D, while institutional quality is a horizontal determinant of growth

    Detection of nanoseismic events related to slope instabilities in the quarry district of Coreno Ausonio (Italy)

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    Le cave per l’estrazione di materiale roccioso rappresentano contesti in cui possono aver luogo eventi di instabilità gravitativa causati dalle continue sollecitazioni cui sono soggette le pareti produttive, principalmente connesse alle vibrazioni dovute alle esplosioni necessarie alle operazioni di disgaggio. La necessità di gestione del rischio da frana per la salvaguardia del personale impegnato nell’attività estrattiva ha portato, nel tempo, alla richiesta di attivare sistemi di monitoraggio nelle aree di coltivazione mineraria e di cava. Nel presente lavoro il monitoraggio nanosismometrico, una tecnica di geofisica passiva recentemente sviluppata per le indagini di microsismicità, è stato impiegato nel distretto di cave a cielo aperto di Coreno Ausonio (in provincia di Frosinone). Il monitoraggio nanosismometrico consente l’individuazione e la localizzazione di deboli eventi sismici, fino a magnitudo locale (ML) nell’ordine di -3, attraverso l’impiego di quattro sensori sismometrici disposti secondo una specifica geometria di array detta SNS (Seismic Navigation System). Dopo aver individuato una cava in cui erano programmate esplosioni per la volata delle pareti in roccia, nel corso del 2013 sono state organizzate 3 campagne di acquisizione durante tre giornate, pianificate in modo da monitorare l’area in un periodo compreso da qualche ora prima dell’esplosione alle 24 ore successive. Su una parete della cava non più produttiva è stato effettuato un rilevamento geologico-tecnico che ha permesso di individuare 4 principali sistemi di discontinuità e caratterizzarli in termini di giacitura, resistenza, rugosità, apertura, spaziatura e condizioni idrauliche secondo gli standard ISRM (1978). L’analisi di stabilità della parete in esame, tenuto conto della sua orientazione, ha restituito una scarsa propensione ad eventi di instabilità. Analizzando mediante il software NanoseismicSuite i dati sismometrici acquisiti è stato possibile ottenere i “supersonogrammi”, ovvero particolari spettrogrammi auto-adattanti alle variazioni del rumore sismico di fondo, dai quali sono state definite alcune caratteristiche specifiche di forma d’onda per diverse tipologie di eventi. In base ai supersonogrammi, è stato possibile individuare e localizzare 15 esplosioni, di cui 3 provenienti dalla cava di riferimento e 12 da cave adiacenti del distretto, e 27 deboli eventi di instabilità gravitativa, distinti in 23 eventi di collasso e 4 rotture legate alle fratturazione dell’ammasso roccioso. Le 3 esplosioni avvenute nella cava di riferimento, e quindi aventi coordinate di origine nota, sono state utilizzate per calibrare il modello di sottosuolo, successivamente impiegato per localizzare gli altri eventi registrati. Le rotture sono risultate originate in diverse zone del distretto estrattivo, mentre gli eventi di collasso sono stati localizzati in una specifica area e risultano essere avvenuti prevalentemente in un limitato intervallo di tempo a seguito delle 9 esplosioni registrate nella campagna del 26-27 luglio 2013. Non è stato possibile, invece, individuare eventi riconducibili ad instabilità negli orari di attività di cava a causa dell’elevato livello di rumore apportato dagli strumenti per l’estrazione e la lavorazione del materiale roccioso. Si è escluso che gli eventi di collasso fossero riconducibili direttamente all’attività di estrazione sia perché registrati al di fuori dell’orario di lavorazione delle cave sia perché, analizzando l’intera registrazione per intervalli orari, le frequenze tipiche dei macchinari di lavorazione non sono risultate energizzante. La zona di origine è risultata essere un’area nella quale sono stati rinvenuti detrito sciolto costituito da blocchi eterometrici ed una parete non in coltivazione con medesime caratteristiche delle discontinuità rispetto alla parete sulla quale era stato effettuato il rilevamento geologico-tecnico, ma con diversa orientazione. In definitiva, la fase di sperimentazione ha restituito dei risultati di indubbio interesse consentendo di mettere in evidenza alcune limitazioni del monitoraggio nanosismometrico nel contesto preso in esame, in particolare legate all’eccessiva rumorosità registrata nelle ore di attività di cava. La tecnica appare, comunque, un utile strumento di monitoraggio per i fenomeni gravitativi di debole intensità, in grado di contribuire alla gestione del rischio da frana in aree ad elevata attività antropica ed in ambienti naturalmente predisposti ad instabilità gravitative che possono interessare pareti in roccia.Nanoseismic monitoring is a passive geophysical technique used to identify and locate weak seismic events (down to local magnitudes, ML, around -3). This technique was applied in the open-pit quarry district of Coreno Ausonio (central Italy) to detect possible gravity-induced slope instabilities resulting from quarry rock blasting. After identifying an active quarry, an engineering-geological survey was carried out to characterise the jointed rock mass on an abandoned wall in front of the quarry. Four main joint sets were surveyed and their geometric and mechanical properties were measured in order to carry out stability analyses that evidenced scarce proneness to failure of the investigated wall. The analysis of seismic records obtained during three monitoring surveys, performed through the NanoseismicSuite software, made it possible to detect and characterise 15 blasts, of which 3 from the reference quarry and 12 from nearby quarries within the district, as well as 27 weak slope instability events (23 collapses and 4 failures). While failures originated from different areas of the quarry district, collapses occurred in a site characterised by an abandoned quarry having a wall more prone to gravity-induced instabilities than the one previously characterised

    Rock mass characterization coupled with seismic noise measurements to analyze the unstable cliff slope of the Selmun Promontory (Malta)

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    In the Mediterranean area, cliff slopes represent widespread high-risk landforms as they are highly frequented touristic places often interested by landslide processes. Malta represents a significant case study as several cliffs located all around the island are involved in instability processes, as evidenced by wide block-size talus distributed all along the coast line. These diffused instabilities are related to the predisponding geological setting of Malta Island, i.e. the over-position of grained limestone on plastic clay deposits, that induces lateral spreading phenomena associated to falls and topples of different-size rock blocks and is responsible for a typical landscape with stable plateau of stiff rocks bordered by unstable cliff slopes. The ruins of GĆ«ajn ĆŞadid Tower, the first of the thirteen watchtowers built in 1658 by the Gran Master Martin de Redin, stand out in the Selmun area. Currently the safety of this important heritage site, already damaged by an earthquake on October 12th 1856, is threaten by a progressive moving of the landslide process towards the stable plateau area. During autumn 2015, a field campaign was realized to characterize the jointed rock mass. A detailed engineering-geological survey was carried out to reconstruct the geological setting and to define the mechanical properties of the rock mass. Based on the surveyed joint spatial distribution, 58 single-station noise measurements were deployed to cover both the unstable zone and the stable area. The obtained 1-hour records were analyzed in the frequency domain for associating vibrational evidences to different instability levels, i.e. deriving the presence of already isolated blocks by the local seismic response. The here presented results can be a useful contribute to begin to asses defense strategies for the Selmun Promontory, in the frame of managing the landslide risk in the study area and preserving the local historical heritage

    Volumetric analysis of carotid plaque components and cerebral microbleeds: a correlative study

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    PURPOSE: The purpose of this work was to explore the association between carotid plaque volume (total and the subcomponents) and cerebral microbleeds (CMBs). MATERIALS AND METHODS: Seventy-two consecutive (male 53; median age 64) patients were retrospectively analyzed. Carotid arteries were studied by using a 16-detector-row computed tomography scanner whereas brain was explored with a 1.5 Tesla system. CMBs were studied using a T2*-weighted gradient-recalled echo sequence. CMBs were classified as from absent (grade 1) to severe (grade 4). Component types of the carotid plaque were defined according to the following Hounsfield unit (HU) ranges: lipid less than 60 HU; fibrous tissue from 60 to 130 HU; calcification greater than 130 HU, and plaque volumes of each component were calculated. Each carotid artery was analyzed by 2 observers. RESULTS: The prevalence of CMBs was 35.3%. A statistically significant difference was observed between symptomatic (40%) and asymptomatic (11%) patients (P value = .001; OR = 6.07). Linear regression analysis demonstrated an association between the number of CMBs and the symptoms (P = .0018). Receiver operating characteristics curve analysis found an association between the carotid plaque subcomponents and CMBs (Az = .608, .621, and .615 for calcified, lipid, and mixed components, respectively), and Mann-Whitney test confirmed this association in particular for the lipid components (P value = .0267). CONCLUSIONS: Results of this study confirm the association between CMBs and symptoms and that there is an increased number of CMBs in symptomatic patients. Moreover, we found that an increased volume of the fatty component is associated with the presence and number of CMBs

    Structural properties of the linkers connecting the n- and c- terminal domains in the mocr bacterial transcriptional regulators

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    Peptide inter-domain linkers are peptide segments covalently linking two adjacent domains within a protein. Linkers play a variety of structural and functional roles in naturally occurring proteins. In this work we analyze the sequence properties of the predicted linker regions of the bacterial transcriptional regulators belonging to the recently discovered MocR subfamily of the GntR regulators. Analyses were carried out on the MocR sequences taken from the phyla Actinobacteria, Firmicutes, Alpha-, Beta- and Gammaproteobacteria. The results suggest that MocR linkers display phylum-specific characteristics and unique features different from those already described for other classes of inter-domain linkers. They show an average length significantly higher: 31.8 Â± 14.3 residues reaching a maximum of about 150 residues. Compositional propensities displayed general and phylum-specific trends. Pro is dominating in all linkers. Dyad propensity analysis indicate Pro–Pro as the most frequent amino acid pair in all linkers. Physicochemical properties of the linker regions were assessed using amino acid indices relative to different features: in general, MocR linkers are flexible, hydrophilic and display propensity for β-turn or coil conformations. Linker sequences are hypervariable: only similarities between MocR linkers from organisms related at the level of species or genus could be found with sequence searches. The results shed light on the properties of the linker regions of the new MocR subfamily of bacterial regulators and may provide knowledge-based rules for designing artificial linkers with desired properties. © 2016 The Author(s

    The Building Information Model and the IFC standard: analysis of the characteristics necessary for the acoustic and energy simulation of buildings

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    The new European Directive 2014/24 / EU requires for all member States the use of BIM procedures in the construction of public buildings. The countries belonging to the European Union shall be obliged to transpose the Directive and adapt their procedures to that effect. The paper analyzes the IFC format, the only recognized by the European Directive Standards for BIM procedures, in order to assess its use for simulations of buildings. IFC, described by the ISO 16739 (2013), is today a standard that describes the topology of the constructive elements of the building and what belongs to it overall. The format includes geometrical information on the room and on all building components, including details of the type for performance (transmittance, fire resistance, sound insulation), in other words it is an independent object file for the software producers to which, according to the European Directive, it will be compulsory to refer in the near future, during the different stages of the life of a building from the design phase, to management and possible demolition at the end of life. The IFC initiative began in 1994, when an industry consortium invested in the development of a set of C ++ classes that can support the development of integrated applications. Twelve US companies joined the consortium: these companies that were included initially are called the consortium "Industry Alliance for Interoperability". In September 1995 the Alliance opened up membership to all interested parties, and in 1997 changed its name to "International Alliance for Interoperability". The new alliance was reconstituted as a non-profit organization, with the aim of developing and promoting the '' Industry Foundation Class "(IFC) as a neutral data model for the building product that were useful to gather information throughout the life cycle of a building facility. Since 2005 the Alliance has been carrying out its activities through its national chapters called SMART building. The present study aims at evaluating the IFC, comparing the information and data contained in it, with other formats already used for energy simulations of buildings such as the gbXML (Green Building XML), highlighting the missing required information and proposing the inclusion of new ones to issue the energy and acoustic simulation. More generally the attention is focused to building physics simulation software devoted to exploit the BIM model potential enabling interoperability

    Coming Back to Sustainability: Technological Solutions for an nZEB

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    When man needed the first time to find a shelter, he conformed himself to environmental context, finding in it resources and benefits. Then progress brought man to see Nature as a servant rather than as a valuable ally. The abuse of natural resources has revealed how critical the concept of renewability is and forced man to review his actions. In the last decade sustainability in building design stopped being just an ideal and turned into a duty to fulfill. In order to reduce energetic consumption and CO2 emissions, according to the new European directives, a sustainable building must satisfy performance and functional needs, with the minimal environmental negative effect. Rely on technology is not enough: a valid architectural solution depends strictly on the study of materials, architectural technologies, typological forms of environmental context, which becomes again the best guideline for the designer to draw a proper design, comparing tradition and innovation. For this reason, numerous energy volunteer protocols were developed to meet the demand for high energy-efficient buildings, the nZEB. This study shows how the German Passivhaus is applied to a scholastic building. The strict requirements of the standard are achieved thanks to a reasoned development, which leads to tailored technological, material and plant design solutions of the location where it is applied. After considerations about form and orientation, the building envelope is the main part to focus on: it has to be conceived as a complex multi-functional filter between internal and external environment, responding to structural and performance targets but also to energy efficiency. Man has to cooperate with nature to design energy efficient buildings and environmentally friendly with the users, but mostly to meet new needs for environmental compatibility
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