1,720,973 research outputs found
Experimental Investigation of Lightweight Mortars Based on Recycled Olive Kernel through Hygric and Mechanical Characterization
No full textBio-based building materials are now being widely explored by researchers to promote their effective use and reduce the environmental impact of building construction. Among these, mortars based on olive kernel aggregate, a waste product of the production of olive oil, can be effectively adopted for moderate load-bearing applications in buildings thanks to their lower density and thermal conductivity,compared to traditional sand-based mortars. Nevertheless, to date most of the researchers focused on mortars produced with a partial substitution of traditional sand with olive kernels and relatively high dosages of binder. In this work, mortars entirely based on olive kernel aggregate were produced employing limited dosages of binder. Mechanical, hygric properties and the density were evaluated on the hardened materials for different tested formulations. Results showed a high dependency of mechanical properties on the dosage of binder and demonstrated their employability for moderate load-bearing applications in buildings
Multiscale simulation of salt crystallization-induced damage in porous materials
No full textIn this paper, a multiscale modelling strategy to simulate salt crystallization-induced damage in porous materials is proposed. Salt crystallization pressure exerted on pore walls is explicitly modelled on a nonlinear representative volume element (RVE) at the microscale of the porous medium. A macroscopic damage measurement of the whole RVE can be then extracted for any combination of crystallization pressure and pore filling time histories. The efficient coupling of moisture transport and salt crystallization with micromechanical damage is achieved by adopting a state-of-the-art multiphase model for the transport/crystallization part and by originally formulating an efficient phenomenological damage model, trained on a dataset generated through micromechanics-based simulations on RVEs. The effectiveness of this numerical strategy is shown via the comparison with an experimental campaign on salt-aged traditional Dutch tiles. The proposed numerical strategy appeared able to track the evolution of macroscopic damage in real-time along with salt transport and crystallization within the porous medium. The potential for using the proposed framework with extended datasets and simulation-driven machine learning is also highlighted
A two-step automated procedure based on adaptive limit and pushover analyses for the seismic assessment of masonry structures
Full text linkIn this paper, a two-step automated procedure based on adaptive limit and pushover analyses is developed for the seismic assessment of masonry structures. Inspired by an akin procedure previously developed by the authors for the out-of-plane behaviour, the procedure herein presented is extended to in-plane and combined in- and out-of-plane loading conditions, accounting also for the effect of masonry crushing failure. In the first step, an upper-bound adaptive limit analysis tool is used to predict the collapse mechanism (and the corresponding multiplier) of the structure given a certain loading condition. A novel ad-hoc routine is then developed and utilized for the automatic import of the collapse mechanism geometry of any complexity into a solid model ready to be used in a finite element framework. In the second step, cohesive-frictional contact-based interfaces are automatically inserted in the cracks of the collapse mechanism formerly obtained, and a pushover analysis is conducted to investigate the load–displacement response of the structure. A series of parametric analyses are conducted to highlight the effect of different mechanical assumptions. Finally, the effectiveness of the procedure proposed is shown on a full-scale masonry building case study
Advancing Cultural Heritage Structures Conservation: Integrating BIM and Cloud-Based Solutions for Enhanced Management and Visualization
Full text linkPreserving and managing historical cultural heritage necessitates innovative approaches that harmonize technology with historical documentation. This paper presents a case study showcasing an adaptable online database tailored for the incorporation of Building Information Modeling (BIM) models and associated historical records. Notably, this approach offers distinctive integration with historical data, enabling users to contextualize heritage assets historically. The study delves into the database’s capabilities, focusing on its role in cultural heritage structure management. It explores interactive exploration, semantic querying, and attachment features, highlighting BIM’s potential in digital conservation, documentation, and archival efforts for historical structures. Additionally, the paper underscores the database’s significance as a valuable tool for education, research, and collaboration among heritage professionals and the public. While addressing specific modeling challenges, it emphasizes the importance of enhancing software solutions to elevate historical asset management. Historical BIM emerges as a powerful resource bridging the gap between historical structures’ conservation and modern technology
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
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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