1,721,138 research outputs found
STIMA DEI PROFILI DI VELOCITA’ DEI FLUSSI IPERCONCENTRATI: analisi di sensitività sui parametri dell’equazione di Bagnold
Full text linkNel presente lavoro l'attenzione è focalizzata sulla dinamica di propagazione delle colate detritiche, fenomeni naturali di elevata pericolosità e forza distruttiva.
Com’è noto, una colata detritica si verifica quando il materiale solido (sedimenti e materiale sciolto) di versanti caratterizzati da elevate pendenze viene destabilizzato dal deflusso di ingente volume d’acqua. Durante la propagazione della miscela acqua-sedimento, elementi anche di elevata dimensione (massi, alberi,..) possono essere mobilitati aumentando la forza distruttiva della colata con conseguenti possibili ingenti danni a edifici e infrastrutture, perdita di vite umane e ostruzioni (parziali o totali) dei corsi d’acqua interessati
Significance of hydraulic complexity parameters M1 and M2 based on the laboratory and field data
Full text linkHydraulic complexity metrics referred to as M1 and M2 play an important role when it comes to the analysis of habitat metrics. In the present paper, the significance of these parameters is analysed by using laboratory data as well as field observations along the Tiber River in Italy.
Based on the laboratory data, the estimated parameters allow us to characterise the high/low-velocity areas. Based on field observations, larger magnitudes of M1 are linked to the zones with large changes in cross-sectional flow velocity. Larger magnitudes of M2 are observed at the left bank of the channel for all flow conditions, suggesting locations with larger kinetic energy consumption for aquatic organisms.
Overall, the findings of the present research would be of particular interest in quantifying biologically important flow patterns occurring at different spatial scales within different streams and flow conditions
INVESTIGATION OF THE UNDERGROUND BUILDING HERITAGE AND THE MECHANISM OF WATER FLOWING IN QANĀTS IN PALERMO THROUGH INNOVATIVE SURVEYING TECHNIQUES
Full text linkThe valorisation, protection and preservation policies for the underground building heritage are often difficult to implement due to an inadequate knowledge of hypogeal constructions. The complex and widespread underground structures of the vast “Cavo” Heritage (“horizontal wells”, “shelf wells” or “well tunnels”), so called qanāts, hidden underground and built over the centuries in Palermo, representing an evocative testimony to the history of water culture in the ancient city. Through the historical and constructive analyses and the implementation and development of measurement and 3D representation and visualization, first actions have been carried out. The paper will present the first results of the restoration project and the path of re-introduction in the fruition network of the qanāt “Gesuitico alto”, developed also in the field of “iHeritage. Mediterranean Platform for UNESCO Cultural Heritage” project, financed by ENI CBC MED Programme 2014-2020. The paper presents an experimentation of a procedural workflow of data acquisition, analysis and subsequent 3D virtual navigation of hypogeal environments. The methodology used is the SLAM with a last generation WMLS. The platform of virtual reality visualization, within UnReal Engine, allows the user to immerse and navigate in the anthropic environment by engaging it with a set of infographics that highlight the virtual visit
Going 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
Flow characteristics of a channelized debris-flow and implications in numerical modelling: a study case
No full textAs it is known, debris flows are characterized by extreme propagation rapidity and by the ability to move high
quantity of fluid mass. Furthermore, debris flows are fluid enough to travel long distances and, thus, to cause
damage in vast areas, even far from the trigger ones. Debris-flow runout estimations are important for the
delineation of potentially hazardous areas. Especially in recent years, several researches have been conducted
in order to define predicitive models. But, existing runout estimation methods need input parameters that can
be difficult to estimate. Recent advances in theory and in experimental research have allowed the assessment
of the physics of the debris flows. On one hand, analysis of flows of dry and solid- fluid mixtures (Azana et al,
1999; Spinewine et al., 2003) have provided a foundation for a comprehensive debris flow; on the other hand,
experimental data have highlighted the limitations of the theoretical models. The major part of the experimental
studies analyze the basic kinematic conditions which determine the phenomenon evolution. The aim of the present
work is to give a contribution on understanding of the propagation phenomenon of the debris flow providing a
method for choosing input parameters in runout estimation. This parameters are useful in numerical modelling.
The analysis is conducted with the aid of experimental data collected in a laboratory flume appositely constructed
at the Dipartimento di Ingegneria Civile, Ambientale e Aerospeziale – University of Palermo - Italy. Propagation
conditions are analyzed for different granular concentrations
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