1,720,972 research outputs found
Effect of geosynthetic reinforcement inclusion on the strength parameters and bearing ratio of a fine soil
No full textThis paper reports an investigation on the beneficial effects of reinforcing a fine soil with a geosynthetic (reinforcement geocomposite) and their behaviour under loading. The effectiveness of the reinforcement was investigated through triaxial and California Bearing Ratio, CBR, tests. The triaxial tests showed that including the reinforcement provided additional confinement to the reinforced soil samples, causing an increase in the corresponding strength parameters. However, the reinforcement decreased the secant stiffness modulus of the composite material, particularly for low strains. The CBR tests were performed on soaked samples, compacted for different initial water content values. The influence of increasing the number of reinforcement layers was also analysed. The results showed that the reinforced samples had a maximum bearing capacity larger than the unreinforced material. The reinforcing mechanisms observed in the CBR tests were membrane tension support and bearing capacity increase. Increasing the number of reinforcement layers induced an improved response of the soil-geosynthetic composite material, particularly for a water content lower than the optimum. An increase in the initial water content induced reductions of the bearing capacity of the soil, with different values, depending on position of the initial value relative to the optimum water content
Bearing ratio of a fine soil reinforced with geosynthetics: influence of the reinforcement type and the soil water content
No full textThis paper reports an investigation on the effects of reinforcing a fine soil with three different geosynthetic solutions and their behaviour under loading. The effectiveness of the reinforcement was investigated through California Bearing Ratio, CBR, tests. The reinforcement solutions tested were: geogrid (GGR), geocomposite (GCR), association of geogrid and geotextile (GGR + GTX). The response of the unreinforced fine soil was compared to those of the same soil with one layer of reinforcement. The influence of the initial water content of the soil on the bearing capacity was analysed using five different values (11.9%; 13.9% (optimum); 15%; 17% and 19%). Including a layer of reinforcement improved the bearing capacity ratio and the stiffness of the samples. The best improvement in bearing capacity was found for GGR, followed by GGR + GTX and then GCR, and can be explained by the differences in stiffness and structure of the reinforcements. The mobilisation of the reinforcement depended on the type of reinforcement, the initial water content of the sample and the penetration induced to the sample. The soil initial water content affected the response significantly. Higher initial water contents lead to lower CBR values, for both unreinforced and reinforced samples. However, the effectiveness of each reinforcement varied with the initial water content; for GGR and GGR + GTX an initial water content of 17% lead to the higher bearing capacity ratio, while for GCR this occurred for the lowest value of the initial water content considered (11.9%)
Parametric study of the design of a solution of fine soil reinforcement with geosynthetics
No full textThis paper presents a parametric study regarding the effect of several parameters used by the design method of British Standard BS8006-1: 2009 for the design of reinforced soil structures. The study consists in two parts. In the first part the design of a structure is performed using solutions which include one type of soil and five different geosynthetics. In the second part of the study a more extensive parametric study was conducted where relevant ranges of several properties were considered. These properties are: (1) the coefficient of friction and the adhesion coefficient between the soil and the geosynthetic; (2) the ultimate tensile strength of the geosynthetic; (3) the partial material factor for the reinforcement; and (4) the total horizontal width of the top and bottom faces of the reinforcing element at the layer (per meter). The external stability is verified with the same standard. Among other things, the results of this study allow to conclude that the use of different properties of interaction between the soil and the reinforcement is important only for the internal mechanism of failure by pullout; the pullout mechanism is more important for the design of solutions where reinforcements that have a higher tensile strength were considered. The total horizontal width of the top and bottom faces of the reinforcing element at the layer is important for the appearance or not of the pullout
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe 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
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