1,721,003 research outputs found
Volcanic debris avalanche and debris flow hazard assessment: contributions from geological and geotechnical characterization of the volcaniclastic deposits of the Cotopaxi Volcano (Ecuador).
No full textImpact of historical landslides on natural landscape and human settlements in the core of the Alps: the Piuro 1618 disaster in the Bregaglia Valley.
No full textNatural disasters, such as postglacial landslides in Alpine valleys, recurrently reshape the natural and human landscape, impacting on settlements, land-use and architecture. Historical catastrophes were sometimes narrated and painted, so that in these cases chronicles and artistic representations can be integrated to geological, geomorphological, geophysical and archaeological data to describe the co-evolution of the natural and cultural landscape. This is the case of the Piuro landslide that in 1618 almost completely buried this renown and rich trading town in the Bregaglia Valley (Italy), on the way to the relevant alpine Maloja pass. Since it totally modified the valley floor, the catastrophe represents a turning point that permits to i) attempt the 3D reconstruction of the natural and archaeological landscape before and immediately after the disaster, ii) unravel the post-1618 increments of evolution of the natural landscape and settlements, iii) retrieve the memory of the area that underwent the disaster. To accomplish these aims we integrated: a new detailed DTM; a reconstruction of the relative chronology of burial, erosion and stabilization of the landforms after natural and anthropic processes pre- and post-dating the 1618 landslide; some subsurface stratigraphic logs and images based on new boreholes and geophysical surveys; age determinations based on radiocarbon and archeological/historical data; chronicles and paintings depicting the Piuro area before and after the disaster. The images we could draw show how human settlements were continuously controlled by the occurrence of landslides and other catastrophic processes like debris flows, before and after the 1618 landscape turning point. In the valley center we could detect a pre-1618 landslide body, whose mega-boulder reliefs were settled at least since the 4th – 5th century AD, at present buried below the Middle-ages and Renaissance Piuro villages. These landslide bodies provided also favorable settings for food preservation, whose memory and usage survived and reached the present-day under the vernacular denomination of “crotti”. At the millennial time scale no stable geomorphological surfaces do exist on the valley floor and lower slopes, since we could map the chronology of building of the debris flow-fan lobes, demonstrating how they evolved before and after the 1618 landslide, burying and/or being buried by the two major landslide bodies and interfingering with the trunk river alluvial sediments. Radiocarbon age determinations, archeological findings and the known ages of historical buildings permitted to recognize the geomorphological surfaces that remained stable on a shorter, secular, time scale, where the settlements could resume still competing with catastrophic processes that led to repetitive burial of several buildings during the last three centuries. Based on these results we could draw the 3D models of the Piuro area predating and immediately postdating the 1618 catastrophe. Historical paintings and chronicles largely confirm the relative chronology of landscape changes that we propose.
The present work was co-funded through the EU, Regional Development European Fund, by Italian State, Helvetic Confederation and Cantons under the Interreg V-A IT-CH 2014-2020 Cooperation Program - A.M.AL.PI.2018 “Alpi in Movimento, Movimento nelle Alpi. Piuro 1618-2018", ID 594274 – Axis 2 “Cultural and natural enhancement”
Valutazione dell’efficienza delle iniezioni di resine espandenti per il consolidamento dei terreni di fondazione mediante prove geotecniche e indagini di tomografia elettrica tridimensionale.
No full textTecniche di consolidamento di terreni mediante iniezioni di resina espandente sono state utilizzate con buon successo, quando le cause di cedimento differenziale verticale delle strutture di fondazione sono connesse ad alterazioni naturali e/o antropiche del terreno di fondazione e/o a una non corretta progettazione/esecuzione dell’opera. Tra le diverse tecniche di consolidamento dei terreni mediante iniezioni di resine espandenti, è stato ideato un procedimento che prevede, in abbinamento alle tradizionali prove geotecniche, l’applicazione di metodi geofisici, in particolare della tomografia di resistività elettrica 3D, per poter acquisire, anche nei volumi di terreno difficilmente accessibili, quelle informazioni necessarie al progetto del consolidamento e al suo monitoraggio in corso d’opera. E’ secondo questo approccio di intervento, e con modalità del tutto simili alle condizioni di cantiere, che vengono presentati i risultati ottenuti in un campo prove in vera grandezza, interessato da iniezioni di resina espandente poliuretanica bicomponente
Valutazione dell’efficienza di resine espandenti per il consolidamento dei terreni di fondazione mediante prove geotecniche e indagini di tomografia elettrica tridimensionale. ISBN 9788897517047,
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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