1,720,991 research outputs found
Laboratory Scale Seismic Surface Wave Testing for the Determination of Soil Elastic Profiles
Get PDFSeismic surface wave testing is well-adapted to the study of elastic parameters and, hence, the elastic profile of soils in the field. Knowledge of a ground’s stiffness profile enables the prediction of ground movement and, thus, the quality of the foundation. The stiffness parameter obtained in this research corresponds to the measurement of the seismic surface wave phase velocity of materials, which relates to the very small strain shear modulus. This paper describes a methodology for performing surface wave testing in the laboratory. In comparison with field tests, a laboratory-scale experiment offers the advantage of allowing the process of data collection to be calibrated, and analytical studies can be carried out as the properties of the material under test are controllable and known a priori. In addition, a laboratory scale experiment offers insight into the interaction between the seismic surface wave, the soil, the boundary and, hence, the constraints associated with the seismic surface wave technique. Two simplified models of different sizes were developed using homogeneous remoulded Oxford Clay (from Midlands region of the UK). The laboratory experimental methodology demonstrated that the seismic surface wave equipment used in the laboratory was directly influenced by the clay properties as well as the size of the test model. The methodology also showed that the arrangement of the seismic source and the receivers had an impact on the range of reliable frequencies and wavelengths obtained. 
Stability Analysis of Weathered Rock Cut Slope Using Geological Mapping and Laboratory Tests
Get PDFA study on determining the stability of weathered rock cut slope using
geological mapping and laboratory tests. The study is divided into two parts: field
work and laboratory testing. The field study focused on the measurement and
analysis of the orientation and characteristics of discontinuity. Identification of
rock types, weathering grades and observation of cut slope conditions were also
included in the field study. Laboratory testing involved determination of natural
moisture content, particle size distribution and shear strength. Discontinuity data
were analyzed using stereographical method for identification of potential
instabilities. A factor of safety (FOS) analysis was conducted on unstable cut
slopes using SWEDGE software and manual calculation It is found that the
geological mapping and laboratory tests are feasible for assessing slope stability.
The FOS analysis has distinguished 10 slope to be considered as fail whilst the
other 6 are consider stable same as field observation
Seismic evaluation of vibro-stone column
Get PDFGround improvement work is crucial in enhancing the characteristics of weak soils commonly encountered in Civil Engineering, and one such technique commonly used is vibro-stone columns. An assessment of the effectiveness of such an approach is critical to determine whether the quality of the works meets the prescribed requirements. Conventional quality testing suffers limitations including: limited coverage (both area and depth) and problems with sampling quality. Traditionally quality assurance measurements use laboratory and in-situ invasive and destructive tests. However geophysical approaches, which are typically non-invasive and non-destructive, offer a method by which improvement profiles can be measured in a cost effective way. Of these seismic surface waves have proved the most useful to assess vibro-stone columns, however, to date much of the previous work conducted has focussed on field based observations making detailed evaluation of this approach difficult. This study evaluates the application of surface waves in characterizing the properties of laterally heterogeneous soil, specifically for using in the quality control of vibro-stone column. Three models were employed which began with a simple model and extended finally to complex model: (1) concrete mortar was used to establish the method, equipment and its system, (2) pilot test on a small scale soft kaolin to adopt a model vibro-stone column and (3) main test contained a configuration of vibro-stone column in soft Oxford clay. A generic scaled-down model of vibro-stone column(s) was constructed. Measurements were conducted using different arrays of column configuration, using sand to simulate stone material. This idealized set of laboratory conditions were used to provide guidelines for the interpretation of field measurements. The phase velocity obtained from the controlled tests showed close agreement to those reported in literature and with those generated through empirical correlations with vane shear test. The dispersive curve demonstrated an increased phase velocity with increasing wavelength for the measurements on the clay (between columns), and decreased phase velocity with increasing wavelength for the measurements on the column. More interestingly, the results showed that in the characterization of lateral non-homogeneities, the phase velocity versus wavelength relationship varies on stone columns of different diameters and densities. This illustrated that the shear modulus profiles are influenced by the effective region that spans both the lateral and depth axes, and also demonstrated how the results can be influenced by the positioning of sensors with respect to the survey target. This research demonstrates how Rayleigh waves can be used for quality assurance when constructing vibro-stone columns
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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