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Linee guida per la valutazione e la mitigazione del rischio valanghe di neve sulle infrastrutture e costruzioni
Full text linkA numerical displacement-based approach for the structural analysis of cable nets
Full text linkA new displacement-based approach is proposed herein to predict the behaviour of pre-tensioned cable nets subjected to vertical loads. The cables are contained in horizontal plane and have a single degree of freedom in each node, where loads are applied. The model is based on the equilibrium equations of an infinitesi mal cable-element, which are solved by considering the catenary equation under the hypothesis of (a) zero bending stiffness, (b) linear elastic behaviour of materials, (c) small deformation, and (d) the existence of perfect hinges in each node. More precisely, a finite-difference numerical procedure is introduced in order to evaluate nodal displacements related to a set of applied vertical forces. The effectiveness of the proposed approach is then assessed by comparing the numerical results with those obtained by other models found in the current literature. Finally, the proposed approach is used to design new and more efficient insulating panels for the green house technology
Temperature Effect on the Relationship between Flexural Strength and Compressive Strength of Ice
No full textThe practical usage of ice has increased significantly in recent times, as it is a readily available material utilized in various applications, such as temporary constructions and permanent hydraulic structures. Consequently, there is a growing practical interest in developing models that can accurately compute the flexural strength of ice based on its compressive strength.
Following the testing procedure recommended by UNI EN 196 for cement-based mortars, three point bending, and compression tests were conducted on 40 mm × 40 mm × 160 mm ice prisms, specifically prepared under different temperature conditions. Through these tests, the ratio
between flexural and compressive strengths of ice was determined. As the effect of temperature on ice is comparable with that of water/binder ratio on cement-based mortars, the flexural/compressive strength ratio of ice also depends on the frozen temperature
A Reverse Dynamical Investigation of the Catastrophic Wood-Snow Avalanche of 18 January 2017 at Rigopiano, Gran Sasso National Park, Italy
Full text linkOn 18 January 2017 a catastrophic avalanche destroyed the Rigopiano Gran Sasso Resort & Wellness (Rigopiano Hotel) in the Gran Sasso National Park in Italy, with 40 people trapped and a death toll of 29. This article describes the location of the disaster and the general meteorological scenario, with field investigations to provide insight on the avalanche dynamics and its interaction with the hotel buildings. The data gathered in situ suggest that the avalanche was a fluidized dry snow avalanche, which entrained a sligthtly warmer snow cover along the path and reached extremely long runout distances with braking effect from mountain forests. The avalanche that reached the Rigopiano area was a “wood-snow” avalanche—a mixture of snow and uprooted and crushed trees, rocks, and other debris. There were no direct eyewitnesses at the event, and a quick post-event survey used a numerical model to analyze the dynamics of the event to estimate the pressure, velocity, and direction of the natural flow and the causes for the destruction of the hotel. Considering the magnitude and the damage caused by the event, the avalanche was at a high to very high intensity scale
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
Snow gliding and glide snow avalanches: recent outcomes from two experimental test sites in Aosta Valley (NW Italian Alps)
Full text linkWe have been continuing our research on snow gliding and glide snow avalanches in two experimental test sites in Aosta Valley Region. The sites are located in the Monterosa Ski resorts at 2100-2200 m a.s.l. and are equipped with a couple of glide-snow shoes, temperature and volumetric liquid water content (VLWC) sensors in the soil (at 5 and 15 cm depths) and in the basal snowpack layer. In the surrounding a manual snow station and an automatic weather station recorded snow and weather data. Starting from the preliminary presentation given at the ISSW 2014, we are now able to present new outcomes deriving from different analyses made on a more complete database. In the two monitoring seasons 2013-14 and 2014-15 we registered 9 glide snow avalanches: 2 cold and 7 warm-temperature events. A simple descriptive statistics of the variables registered at the moment of the glide avalanche events showed that the cold glide snow avalanche events were characterized, in average, by: i) a higher soil VLWC (26.9 % and 25.3 %) than in case of warm events (25.6 % and 24.9 %) at 5 cm and 15 cm depths, respectively; ii) a lower VLWC (0.6 %) in the snowpack basal layer than in case of warm events (2.5 %); iii) a slightly higher soil temperature at 5 and 15 cm depths (difference of 0.1 and 0.3 °C respectively) than in case of warm events. In the only warm glide snow avalanche event which presented a continuous gliding before, the daily glide rate showed a significant exponential relationship with the soil VLWC at both depths. Conversely, we did not found any relationship between the glide rate and the driving factors in the continuous cold gliding periods, as we have recently found in another experimental test site in the same region. In conclusion, this study contributes to assess the importance of soil VLWC, which seems to be one of the most important driving factor for gliding processes. Therefore, this study supports the need, already suggested by other scientists, of analysing such processes with an interdisciplinary approach which integrates snow and soil sciences
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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