1,721,041 research outputs found
Mining impact on stream sediment quality in County Antrim, Northern Ireland
Full text linkHistorical mining activity has in some cases released large quantities of heavy metals into the fluvial environment of many settings around the world. County Antrim is one of the main areas in Northern Ireland known for historical mining, where 780 shafts and adits are associated with iron ore exploration, and where historically, ca. 700,000 tonnes of bauxite were produced. In order to assess the legacy of mining operations, it is important to understand the present (baseline) chemistry of the natural environment. Heavy metals resulting from mining activities need to be distinguished from products of natural variation and geological processes.
Using geographic information systems (GIS) and multi-element diagrams ("spidergrams") for analysis, the project modelled the geological background of the area, and was able to distinguish whether high metal concentrations in stream sediments were of mining or of natural origin. Sub-catchments with enhanced sediment element concentrations relative to the geological background were identified; and enrichment factors (EFs), as a classification of the degree of enhancement above natural geological background due to mining activities, were calculated.
Results of this study reveal that stream sediment compositions are mainly determined by the underlying geology. Sediment quality guidelines for As, Cd, Cu, Pb and Zn were exceeded by <10% of the samples in most sub-catchments, although 31% of the samples exceeded the guideline for As in the north-eastern coastal Glendun River sub-catchment. By contrast, more than 80% of the samples exceeded the sediment quality guidelines for Cr and Ni in most sub-catchments within the study area. However, these high, Cr and Ni (and also Cu) concentrations do not result from mining activities, and most likely reflect the association with their geological parent material.
Mining (mainly iron ore and bauxite) has had no detectable impact on sediment quality in nine sub-catchments, while three coastal sub-catchments showed slight enrichments of either As and Sn or As, Ag, Co, Sb and Sn. However, as the EFs do not exceed 1.5, their enrichment can be classified as minor
The G-BASE field database
Full text linkSince the 1960s British Geological Survey (BGS) geochemists have routinely recorded site and sample information on field cards. The Geochemical Baseline Survey of the Environment (G-BASE) Project completes a field card for every site sampled and, from the 1980s onwards, field data have been entered into a field database as the samples were collected. In the 1990s a corporate Geochemistry Database was set up using ORACLE to encompass all geochemical data gathered throughout BGS for the UK landmass, including sample and site information. This required a standardisation of coding on field cards both within geochemical activities and in relation to the use of BGS codes, for example the description of rocks and minerals.
In order to load all the data from the G-BASE field cards it is necessary to coordinate the process from completing the card on location; inputting data into the field database, and to the concluding process of loading the field data to the BGS corporate Geochemistry Database. In the past there have been some incompatibilities between the field and corporate database so not all the field data were being captured into the Geochemistry Database.
This report describes new and revised protocols to be used throughout the process of G-BASE field data gathering and to populating the Geochemistry Database. It details the codes that are to be used and the translations that are necessary to transfer from the G-BASE format to Geochemistry Database format. The history of the use of field forms and field databases in G-BASE is described. This manual establishes a reference point in the field data gathering process from which future changes can be documented.
The report appendices list some of the more useful domain tables from the Geochemistry Database and give worked examples of how field information can be used to retrieve analytical results from the database
Geochemical baseline data for the urban area of Lincoln
Full text linkThis report presents the results of an urban soil geochemical survey of Lincoln carried out by the British Geological Survey (BGS) during 1997. The study was undertaken as part of the BGS systematic Geochemical Surveys of Urban Environments (GSUE) project. The concentrations of many potentially harmful elements (PHE) such as As, Cd, Cr, Ni and Pb are enhanced in city environments as a result of urbanisation and industrial processes and their distribution is of concern under current UK environmental legislation.
The GSUE data provide an overview of the urban geochemical signature and because they are collected as part of a national baseline programme, can be readily compared with soils in the rural hinterland to assess the extent of urban contamination. The aim of the present study was to generate urban soil geochemistry information for Lincoln to aid planning and development.
Urban surveying was based upon the collection of samples on a systematic 500 m grid. Soils were sampled at a density of 4 per km2 across the built-up area. Samples were collected from open ground as close as possible to the centre of each 500 m grid cell.
Preliminary interpretations of the data in relation to the underlying geology and past and present industrial history of Lincoln are presented in this report and demonstrate that there is a significant geological influence over soil geochemistry in Lincoln. Possible anthropogenic influences are likely to be largely related to city centre traffic and industrial activities
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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