1,721,442 research outputs found
Structural vulnerability of old precast building stock: case studies from the period 1940s-1970s
Full text linkThis work aims at evaluating the structural performance indexes of different typologies of reinforced concrete precast industrial buildings built in the 40-70s of last century. Precast industrial buildings belonging to the pioneer era of this technology are quite common all over Italy and were mostly devoted to house industrial activities. As a matter of fact, they were designed according to criteria which are now obsolete, mainly for lower static actions as compared to current codes and without any concept for seismic or fire resistance. As such, they potentially feature strong vulnerability. With reference to two industrial complexes located in Brianza (Northern Italy), both built with successive expansions from the ‘40s to the ‘70s, the structural performances of 10 different typologies representative of the Italian precast building stock of this period are evaluated under static, seismic and fire actions. These typologies include vault roofs with truss systems, restrained arches, tapered beams, and moment-resisting portal frames. A preliminary assessment of the vulnerability associated to these types of structures is performed based on their geometry and reinforcement details. Tentative ranges of cost associated to their retrofit are calculated based on the experience of past interventions gained by the technical partner of the paper
Experimental identification of the shear failure modes of a voided precast wall element subjected to lateral loading
Full text linkThe paper describes the experimental results and the engineering interpretation of shear tests carried out at Politecnico di Milano on precast concrete wall elements characterised by inner lightening cavities contoured by a solid frame. At the base of the solid columns mechanical devices connect the wall element with the lower element or with the foundation. The presence of the lightening cavities does not allow for a clear collocation within the classical structural behaviour of walls or frames. This activity frames into a wider research program focused on an innovative dry-assembled precast system for residential constructions named Domus Dry® patented by DLC Consulting srl of Milan and received main funding from the programme “Brevetti+” (GU 179 02/08/2011). An experimental programme was carried out at the Laboratorio Prove Materiali Strutture e Costruzioni - Politecnico di Milano with the aim of characterising the shear behaviour of the wall under different reinforcement layouts: five full-scale wall specimens reinforced with different layouts were subjected to monotonic and cyclic testing through the application of a horizontal displacement history. Different failure modes corresponded to different reinforcement layouts. Failure in tension-shear was identified for weakly reinforced walls, whilst sliding-shear failure was identified for heavily reinforced walls. The tensile testing of the wall vertical joint performed within the global wall test configuration showed a satisfactory behaviour of the connection. A structural strut & tie modelling of the wall elements has been set to provide an engineering interpretation of the experimental results
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
Characterization of the Tensile Behaviour of Ultra-High Performance Fibre-Reinforced Concrete
No full textWithin the framework of the European Programme Horizon 2020, the Research Project ReSHEALience is currently running with the objective of developing a new approach for the design of structures exposed to extremely aggressive environments, based on durability Durability-Assessment and Life Cycle Analysis (LCA). To this aim, new advanced cementitious materials, called Ultra-High Durable Concretes (UHDC), are under investigation to characterize their tensile behaviour in both ordinary and very aggressive conditions. Tensile characterization on the mixes has been performed via different techniques, mainly based on 4-P Bending Tests (4PBT) and Double Edge Wedge Splitting (DEWS). Starting from the results of indirect tension tests, identification approaches are under development in order to evaluate the effective material behaviour in pure tension. In the paper, the mechanical characterization is reported for a few mixes containing steel and amorphous fibres, also showing the identification procedures adopted
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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