1,720,999 research outputs found

    Influence of Stiffness and Damping Parameters of Passive Seismic Control Devices in One-Sided Rocking of Masonry Walls

    No full text
    This paper analyzes the influence of horizontal damped and undamped restraints in terms of the amplification of the response of rocking masonry walls subjected to seismic excitations. It also makes a practical contribution to the design of antiseismic devices conceived to control rocking motion, avoiding or at least limiting undesirable response amplifications that would lead to local or global failure. A horizontal restraint, simulating an elastoplastic steel tie-rod, was coupled with a damper, whose action is included in a proposed equation of motion. Parametric analyses were performed for three typical façades of masonry buildings, showing that, if the stiffness of tie-rod increases, the seismic vulnerability of a rocking façade is not necessarily reduced. Therefore, the calculation of rocking spectra is recommended in order to identify stiffness ranges in which amplification could occur. A simple method for calculating the design damping coefficient of a shock absorber is proposed and the consequent mitigation of vulnerability is demonstrated in various analysis configurations. Graphs plotting time-dependent ratios between the energy dissipated by the shock absorber and the seismic input energy are shown to be a useful tool for quantifying the effectiveness of the shock absorber itself in dissipating energy. The reduction of these time-dependent ratios occasionally observed for specific earthquake time ranges reveals that adverse frequencies are occasionally present in seismic excitation and allows for the identification of the optimal damping coefficient

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The 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 link
    We 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 link
    We 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

    Author Index

    No full text
    Nao informado

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used

    Rapid and Affordable High Throughput Screening of SARS-CoV-2 Variants Using Denaturing High-Performance Liquid Chromatography Analysis

    Full text link
    Mutations in the receptor binding domain (RBD) of SARS-CoV-2 alter the infectivity, pathogenicity, and transmissibility of new variants of concern (VOCs). In addition, those mutations cause immune escape, undermining the population immunity induced by ongoing mass vaccination programs. There is an urgent need for novel strategies and techniques aimed at the surveillance of the active emergence and spread of the VOCs. The aim of this study was to provide a quick, cheap and straightforward denaturing high-performance liquid chromatography (DHPLC) method for the prompt identification of the SARS-CoV-2 VOCs. Two PCRs were designed to target the RBD region, spanning residues N417 through N501 of the Spike protein. Furthermore, a DHPLC screening analysis was set up. The screening consisted of mixing the unknown sample with a standard sample of a known variant, denaturing at high temperature, renaturing at room temperature followed by a 2-minute run using the WAVE DHPLC system to detect the heteroduplexes which invariably form whenever the unknown sample has a nucleotide difference with respect to the standard used. The workflow was able to readily detect all the variants including B.1.1.7, P.1, B.1.585 B.1. 617.2 and lineages at a very affordable cost. The DHPLC analysis was robust being able to identify variants, even in the case of samples with very unbalanced target concentrations including those samples at the limit of detection. This approach has the potential of greatly expediting surveillance of the SARS-CoV-2 variants
    corecore