1,721,757 research outputs found

    Collapse of a model strip footing on dense sand under vertical eccentric loads.

    No full text
    The paper focuses on the behaviour of a model strip footing, resting on a saturated dense sandy soil, subjected to centred or eccentric vertical loading. Experimental tests, carried out on a small-scale physical model, are able to reproduce effective stress levels equivalent to those prevailing in prototype problems, thanks to the maintenance of a downward steady-state seepage in the soil. The test program consists of three series of tests, each corresponding to an imposed value of hydraulic gradient, and each involving five load eccentricities; one series, in particular, is carried out with still water. Relevant points of load–settlement curves are related to the evolution of soil-footing collapse mechanism, evidenced by the distortion of some vertical coloured sand strips. The collapse mechanism is formed either by one or two sliding surfaces, depending on both load eccentricities and hydraulic gradient values. Significant differences are shown to occur between centred and eccentric loading footing response. Shear strength parameters obtained from back-analyses carried out on load values recorded at the appearance of each sliding surface on the free soil surface, in both hypotheses of associated and non-associated flow rule validity, are adopted to draw, for each test, a theoretical collapse mechanism consisting, in plane strain, of a log-spiral line with adjacent-end tangents; the obtained theoretical sliding surfaces, in turn, are compared to the experimental ones, showing that these latter are either stress characteristic or zero-extension lines depending mainly on cumulative footing displacements and current effective stress level in the soil

    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

    Pore pressure dissipation of highly fissured clays

    No full text
    One-dimensional consolidation of intensely fissured clay masses accounting for fluid exchange between fissures and pores is investigated. As main results, layer thickness does not seem to play the same paramount effect as in classical theories and the use of consolidation coefficients inferred from settlements of small laboratory samples is questioned. For the analysis of pore pressure dissipation, an analog model, made out of elastic springs and pistons inserted in communicating fluid-filled boxes, has been envisioned; the equalizing effect of the saturated porous disc at the base of the sample in a test cell is considered. The behavior of the analog model, discussed on the basis of experimental data, suggests that measurement of interstitial pressures in intensely fissured clays might be affected by important limitations
    corecore