1,720,959 research outputs found
Clay coat diversity in a marginal marine estuary: implications for sandstone reservoir quality
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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
A Mid-Palaeozoic Dipole Low defined from new palaeointensity estimates from Russia and the UK
Get PDFCaprock and overburden characterisation: avoiding leakage of CO2 from CCS sites
Get PDFFine-grained lithologies directly above carbon capture and storage (CCS) reservoirs, commonly act as a sealing caprock for the injected CO2 and are of great importance in restricting upwards fluid escape. Despite their importance, they are usually poorly characterised in terms of sedimentology, pore structure, or diagenetic processes, and how all these processes relate to each other for assessing caprock quality and integrity. Caprocks should be a concern at all CCS sites as they may be texturally and mineralogically unstable in the presence of high CO2 pressure. For that reason, this thesis aims to characterise two caprocks to help understand long term top seal leakage potential of the injected CO2 by presenting a full chain of caprock characterisation and geochemical modelling. The principal aim of the characterisation is to compare and contrast two CCS top seals, the Lower Cretaceous Rodby Shale that is calcite rich, caprock to the Captain Sandstone, and the Palaeocene Lista Shale that is calcite free, caprock to the East Mey Sandstone.
Caprock characterisation was undertaken to investigate the mineralogy, pore systems, and surface area of the Lower Cretaceous Rodby Shale, caprock to the Captain Sandstone, and the Palaeocene Lista Shale, caprock to the East Mey Sandstone, at the UK’s planned Acorn and East Mey CCS sites. Cores from both shales were logged and analysed by X-ray diffraction, light microscopy, and scanning electron microscopy to explore the origin of pore types. Grain size was measured using laser particle size analysis. Nitrogen adsorption and mercury intrusion porosimetry were used to characterise the surface area and pore network in terms of pore body and throat sizes. The key findings of this thesis show that the Rodby is smectite-rich with abundant amount of calcite, quartz silt, and small amounts of albite, kaolinite, and chlorite. The calcite in the Rodby Shale Formation was sourced from benthic microfossils (foraminifera), that have locally recrystalised to pore filling cement. The Lista is smectite-rich but calcite free, with quartz silt, and minor amounts of albite, kaolinite, and chlorite. The mean pore body and throat for the Rodby Shale Formation is 17 nm, and for the Lista Shale Formation it is between 17 and 18 nm, putting both the Rodby and Lista Shale Formations in the mesopore range and indicating a dominance of slit-like pores.
Leakage risk assessment was undertaken on the Rodby and Lista Shale Formations for caprock integrity after CO2 injection. Results show that both caprocks have good potential to act as an effective barrier for CO2 escape based on the calculation of diffusion and post-breakthrough advection rates, along with sealing and stability assessments. Diffusion of CO2 into the caprock was studied further by modelling the effect of diffusion on the Rodby and Lista Shale Formation using geochemical modelling software called PHREEQC. Depending on the caprocks’ mineral composition, geochemical reaction could occur and affect their physical properties, such as porosity and permeability. A one-dimensional CO2 reactive transport (diffusion) model controlled by kinetics was developed to investigate the mutual influences of diffusion and reaction on caprocks. The model targeted the base of the caprock and simulated CO2 over 3000 years at a present-day burial temperature of 65 ˚ C. Two primary chemical reactions were identified within the Rodby and Lista Shale models: the local dissolution and precipitation of calcite, as well as the replacement of albite by kaolinite. Variations in porosity and pH were also observed. In the Rodby Shale, porosity increased by 3% in the cell closest to the CO₂-rich reservoir, while in the Lista Shale, it rose by 1%. However, these increases in porosity do not extend significantly into the caprock, as materials released through dissolution processes in the cell adjacent to the reservoir diffuse into the caprock, resulting in a zone of porosity reduction. Significantly, the slight decrease in porosity in certain regions of the Rodby and Lista Shale Formations could improve their sealing capacity. To conclude, from laboratory analysis and geochemical modelling, the Rodby and Lista Shale Formations are likely to represent good seals for the CO2 injected into the underlying reservoirs
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