1,721,021 research outputs found
Structural behavior of the old masonry bridge in the Gulf of Castellammare
No full textMasonry arch bridges represent a very significant part of the heritage of road and railway artworks all over the word and especially in the Mediterranean area, both in terms of: numbers; reduced environmental impact; and static efficiency. In these cases, the cost of maintenance is often limited to the content and channeling of surface water and control of vegetation, which can eventually take root on the joints of the masonry at the shoulders. In masonry bridges, there are no expansion joints or hinges with support equipment or trolleys, as in metal bridges and reinforced concrete ones, or paint, or resin surface protection, all items that affect the cost of maintenance. The permanent weight of these bridges is very high and, together with the mechanical characteristics of the structure, results in very high strength and stiffness against moving loads. This is one of the most valuable aspects of masonry arch bridges, making it possible to keep open to traffic safely, without repair actions, bridges that are centuries old and which are now subject to vehicular traffic and trains producing actions that are considerably higher than those for which they were originally designed.The purpose of this work was a static check on the old Gate Bridge, a road bridge in masonry which links Corso Garibaldi and Via Giacomo Puccini in the town of Castellammare del Golfo (Trapani province). An extensive experimental research was carried out for in situ mechanical characterization of the constituent materials and static tests were also carried out to study the structural response (load-deflection curves) of the arch bridge. Finally, analytical and numerical analyses were carried out for safety verification of the arch stone and for verification of the serviceability condition. © 2015
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
Fixed strength and stiffness hinges for steel frames
No full textA new type of device able to connect steel beam elements is proposed. Specifically, the device is designed in such a way that the required bending stiffness and limit resistance can be independently imposed. To this goal, the device is realized as a "sandwich" section whose wings possess a particular geometry able to guarantee the required characteristics. Further technological requirement is that the device has to engage plan dimensions equal to those of the elements to which it is connected. The procedure to design the device is presented in the paper with reference to a simple plane steel portal constituted by appropriate profiles in such a way it behaves following an assigned force/displacement diagram. The device is proposed as constraint at the base of the pillars as well as connection node between the beam and the pillars. For each device utilized, even in the same frame, a different limit resistance in terms of bending moment can be fixed. Therefore, the elastic plastic response of the frame to a monotonically increasing load shows a complete independence between elastic and resistance characteristics. The effected application shows the great effectiveness and wide applicability of the proposed device
Capacità in compressione di colonne in calcestruzzo confinato con FRP/Acciaio in presenza di precarico
Full text linkNell'ambito del recupero e rinforzo delle costruzioni esistenti, il confinamento di colonne in calcestruzzo armato con materiali polimerici fibro-rinforzati (FRP) e la tecnica di incamiciatura tramite il sistema combinato di angolari e piatti in acciaio (Steel Jacketing) risultano molto utilizzate, in quanto offrono notevoli vantaggi in termini di incremento della capacità portante e deformativa agli elementi strutturali che presentano carenze di requisiti sismici. L'esecuzione dell'intervento di rinforzo in condizioni di esercizio della struttura implica la presenza di uno stato tenso-deformativo esistente nelle colonne, causato dalla presenza dei carichi gravitazionali. Questo può comportare una variazione degli effetti del confinamento, in quanto la risposta del sistema si differenzia dal caso standard in cui il rinforzo viene applicato in assenza di sollecitazioni agenti. Il meccanismo di confinamento che governa il fenomeno sopra descritto non è coerente con le formulazioni standard proposte e disponibili in letteratura, che sono previste per simulare il comportamento in regime di compressione monotonico e/o ciclico del calcestruzzo confinato; pertanto, in presenza di precarico, la valutazione della capacità resistente e deformativa necessita di più accurate previsioni. Nel presente lavoro, tramite modellazione agli elementi finiti (FEM) con ausilio del software ABAQUS, si analizzano gli effetti del confinamento elastico (FRP) ed elasto-plastico (Steel Jacketing) in presenza di precarico, valutando l'efficacia della risposta rispetto alle trattazioni classiche
Effect of corner over-reinforcing strips on the compressive behaviour of TRM confined masonry columns
No full textSeveral recent works studied the efficiency of inorganic matrix composites, namely Textile Reinforced Mortar (TRM) or Fabric Reinforced Cementitious Matrix, for enhancing the strength and shortening capacity of masonry columns subjected to axial load. Literature studies were addressed to study the great number of variables involved in the problem, such as the nature and the grade of mortar, the strength of the fabric, the number of reinforcing layers, the type, the arrangement and the strength of the masonry, and helped to draw the first technical guidelines for practitioners and designers. All the experimental works highlighted that the actual performance of TRM confinement in masonry members was limited by the premature failure of the external layer in correspondence of the corners of sharp-edged sections, due to the stress concentration, limiting the confinement pressure achievable from the external wrap. This paper presents the result of an experimental investigation which aims to study the effect of a corner strengthening detail on the compressive behaviour of calcarenite masonry columns wrapped with glass TRM. The study was performed by varying the number of textile layers and the grade of the mortar adopted for the composite. The results show that the introduction of a fabric strip in correspondence of the corners can limit the stress concentration at the edges, allowing to exploit the confinement pressure of the TRM and achieving greater strength increases
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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