1,720,984 research outputs found
GEMAS : low density geochemical data for arable and grazing land soils of the UK
Full text linkThis report presents low density geochemical data for arable and grazing land soil from the UK. These soil samples were collected by BGS in 2008 as part of the for EuroGeoSurvey’s (EGS) GEochemical MApping of agricultural and grazing land Soil of Europe (GEMAS) project.
The first phase of the project involved the collection of soil samples across each participating country at a sample density of 1 per 2500 km2. The BGS contribution for the UK is documented in a separate report IR/08/068. Following collection all samples were prepared and analysed by ICP (AES and MS) following aqua regia extraction. Quality control of the geochemical data was carried out, before each member state received their data individually.
This report provides a primary record and presentation of the soil geochemical data for 49 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hf, Hg, In, K, La, Li, Mg, Mn, Na, Nb, Ni, P, Pb, Rb, S, Sb, Sc, Se, Sn, Sr, Ta, Te, Th, Ti, Tl, U, V, W, Y, Zn and Zr) for the 290 soil samples collected in the UK. Additional to the results of element concentrations this report also presents data on pH, total organic carbon (TOC) and cation exchange capacity (CEC) determined for arable (Ap) and grazing land (Gr) soil samples.
The data are displayed as a series of graduated coloured dot maps alongside basic summary statistics to provide an initial overview of the data
G-BASE data conditioning procedures for stream sediment and soil chemical analyses
Full text linkData conditioning is the process of making data fit for the purpose for which it is to be used and forms a significant component of the G-BASE project. This report is part of a series of manuals to record G-BASE project methodology. For data conditioning this has been difficult as applications used for processing data and the way in which data are reported continue to evolve rapidly and sections of this report have had to be continually updated to reflect this fact. However, the principals of data conditioning have changed little since the BGS regional geochemical mapping started in the late 1960s.
The process of data conditioning is based on one or more quality control procedures applied to the geochemical results as received from the laboratories, the degree of conditioning depending on how the data is to be used. The task is based on "blind" control samples being inserted prior to analysis, a system of quality control described in the G-BASE procedures manual. The first of the data conditioning processes is data verification and error checking, essentially assessing whether the laboratory has done what it was asked to do and results are being reported with reasonable accuracy. Shewhart or control charts form an important part of this process.
Once the data has been error checked, verified and accepted from the laboratory, further analysis of the data is carried out. These processes include: a series of x-y plots (of duplicate and replicate samples), more detailed control chart plots, and ANOVA analysis of the duplicate/replicate pairs to allocate variance in the results to sampling, analytical or between site variability. Analysis of both primary and secondary reference material can quantify analytical accuracy and precision. An important part of the data conditioning is the quality assurance and this includes procedures used for dealing with results that have data quality issues and documenting all parts of the data conditioning procedure.
The final part of the data conditioning procedure is necessary in order to use the data in context of other previously analysed data sets. This is the process of normalisation and levelling of the data. In G-BASE this is a very necessary step in order to create seamless geochemical maps and images across campaign boundaries and varying analytical methodologies that have spanned several decades
Geochemistry database audit : historical modifications and conditioning applied to First Series geochemical atlas data
Full text linkThis report describes work undertaken as part of the BGS Information Management Programme, with the aim of improving the quality, metadata attribution and utility of historical regional geochemical data stored in the Geochemistry Database. The particular focus of this report is the status of the earliest geochemical data generated by the ongoing Geochemical Baseline Survey of the Environment (G-BASE) project. Analysis of stream sediment samples collected in northern Scotland between 1969 and 1972 formed the basis of the first four published geochemical atlases covering Shetland, Orkney, Caithness and Sutherland. These four areas form a discrete unit in terms of utilising common sampling and analytical methodologies and are described hereafter as the “First Series” geochemical atlases.
The data held in the Geochemistry Database for these areas has until recently been regarded as of unknown quality, with no known documentation regarding quality issues, intra- or inter-atlas modifications to data. The recent commencement of a systematic database audit, also undertaken as part of the Information Management Programme, has allowed these data to be examined in detail, which, in turn, has led to the production of this report, giving information on historical quality issues and modifications made to data in an attempt to provide a contiguous geochemical baseline for the British land area.
The first part of the report introduces the project while subsequent sections describe the historical approaches taken to error control in G-BASE, and an element by element analysis of the status and quality of data with a record, where possible, of what modifications have been made in the past. The report appendices show historical documents that record modifications made to data that are relevant to the First Series atlases. The provision of the information presented in this report should lead to improved integrity of the database, and in turn increase the confidence of data users and enable informed treatment/manipulation of data to be undertaken during preparation of key products such as national geochemical maps
Completion plan for the Geochemical Baseline Survey of the Environment (G-BASE)
Full text linkIn response to NERC national capability (NC) prioritisation which seeks to end systematic regional geochemical mapping, this report contains options and recommendations for the completion of a national geochemical baseline by the G-BASE project by 31st March 2016. The plan delivers samples and analyses from southern England, an area estimated to be 35,500 km2, approximately 7,000 km2 of which is underlain by Chalk (and so would be unsuitable for drainage sampling).
A number of options for completing a national geochemical baseline are presented based on the current G-BASE strategy but with an overall reduced sampling density. The Panalytical arrangement for XRFS analysis until January 2016 substantially reduces the analytical budget required, and is therefore a most important criterion of the completion plan. However, the Panalytical deal should not be the sole factor that drives the strategy for finishing off G-BASE. In order to maximise the science and opportunities for collaborative research secondary options are proposed for the collection of a variety of sample media from areas of greatest environmental interest. These secondary options will require additional funding to complete the non-XRFS analyses of samples which could include contributions from external organisations.
The proposed work plan is primarily concerned with the “observe and monitor” part of NERC national capability. It excludes any proposal for the data interpretation, modelling and knowledge exchange, and adding value to current geochemical baseline tasks (e.g. London Earth and Clyde Basin) or anything beyond the data gathering phase of completing the geochemical mapping of southern England. It is important that the completion plan does not drive the BGS geochemistry activity into just a sample and data gathering exercise. We must continue to deliver science and information outcomes alongside completing the G-BASE baseline or we will lose the capacity to deliver any science in the future
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
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