1,720,956 research outputs found
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
Overpressure Identification and Petrophysical Evaluation of DIAG Field, Offshore Niger Delta, Nigeria in Nigeria
Get PDFAn accurate prediction of the sub-surface pore pressures is a necessary requirement for safety, economics and efficiency in the drilling of wells for exploration and production of oil and gas. The study therefore is aimed at determining overpressured zone(s) and the lateral extent from seismic and well log data and to evaluate petrophysical parameters of diverse sand units within DIAG Field. Qualitative evaluation of four sand bodies within three wells was determined. The identified sand horizons were correlated across the studied wells and tied to the seismic section. The depth structural maps and the isochore maps of the sand horizons were generated. The results show five over-pressured zones within the study wells which occurred at depth range from 1793.88 m (5919.68 ft) to 2119.62 m (6994.76 ft) and were tied to seismic section.The depth structured map of the overpressured zones were generated. The identified reservoir Sand 1, Sand 2 and Sand 4 can produce both oil and gas with Sand 3 producing only oil. From the petrophysical parameters, it was evident that all the reservoirs are highly prolific. The Movable Hydrocarbon Index for the entire hydrocarbon reservoir is lower than 0.7 indicating a high mobility of the hydrocarbon within the reservoir
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
Aspect of Biostratigraphic and Petrographic Studies of the Late Palaeocene – Eocene sequence of the Eastern Dahomey Embayment, Southwestern Nigeria
Get PDFPetrographic characterization and biostratigraphic distribution of the lithofacies exposed at Ibese and Sagamu were carried out in order to determine the chronology and depositional environment of the associated formations and different microfacies identified with the associated rock units in the embayment. The methods employed include detailed lithostratigraphic description carried out in the field while the carbonate petrography, nannopalae-ontological, palynological and micropalaeontological analyses were carried out in the laboratory. The lithostratigraphy in the Ibese quarry has a thickness of 29.5 m which consist of lower to middle limestone with intercalation of marl with an upper shale and silty sand overburden approximating 2m while the Sagamu quarry has a thickness 30m comprising of lower to middle limestone with an upper shale and lateritic overburden of about 5 m. The limestone intervals assigned to the Ewekoro Formation are dark grayish, fossiliferous and calcitic in some parts, while the shale intervals of the Oshosun Formation are dark and highly fossiliferous. The biostratigraphic results indicate the presence of palynomorphs, calcareous nannofossils and other microfossilsas recovered from the samples in different diversity and abundance. Abundant fossils forms are recorded in some of the samples while others have few and in some cases barren. Cibicides spp. are the only foraminifera recovered. Toweius callosus and Coccolithus formosus are among the calcareous nannofossils retrieved from the samples, while Monoporites annulatusis the most abundant of the palynomorph recovered. Petrographic results show two microfacies units. The biomicrite facies is the most re-occurring while, the biosparite facies is sparse. The environment of each microfacies is determined from available data. The presence of Cibicides spp. and Monoporites annulatus show environments of deposition of the rock units to be open circulated shallow water. The occurrence of Cruciplacolithus formosus and Toweius callosus dated the Akinbo shale as exposed in Sagamu quarry to be Early Eocene while the presence of Cruciplacolithus frequens, Cruciplacolithus tenuis and Toweius eminens dated the Akinbo shale as exposed in Ibese quarry to be Late Palaeocene to early Eocene. The abundance of gastropods, pelecypods, scaphopods and diverse microfacies identified suggest quiet shallow marine environment of deposition for the locations. The presence of Toweius callosus and Coccolithus formosus indicated the age of the Oshosun Formation to be Ypresian (55.8+0.2 Ma) while the Ewekoro Formation age range from Thanetian (58.7+0.2 Ma) toYpresian (55.8+0.2 Ma)
Reservoir Characterization and Estimation of Hydrocarbon Reserves of OJ-Field, Onshore Niger Delta, Nigeria4
Get PDFThe reservoir characterization of OJ-Field in the eastern onshore of Niger Delta was determined using 3-D seismicand well logs data. The main objectives are to access the potential reservoir sands with parameters that control itshydrocarbon distribution, fluid type, identify structures necessary for hydrocarbon accumulation and estimation ofhydrocarbon reserves. Structural maps of horizons in four wells containing hydrocarbon bearing zones with tops andbases at subsea depth range of -6723.93 to -9678.46ft were produced, showing the trapping mechanism to be mainlyfault-assisted roll-over structures. From the four reservoir sands delineated, Sand A (-6723.93 to -7143.18ft) is themost prolific hydrocarbon bearing with 56.07MMbbl of oil and recoverable reserve of 6.46MMbbl while Sand C(-8343.37 to -9203.15ft) is the second most prolific reservoir sand with 49.68MMbbl of oil and recoverable reserveof 11.92MMbbl. Sand D (-8471.83 to -9678.46ft), which is the second least prolific, has 31.17MMbbl of oil,112.74MMcf of gas and 0.94MMbbl recoverable reserve while the least prolific, Sand B (-7181.12 to -7877.56ft),contain 26.05MMbbl of oil with recoverable reserve of 5.25MMbbl. Also, OJ-01 well was the most promising of allthe wells considered with 65.96MMbbl of oil and recoverable reserve of 5.21MMbbl compared with OJ-02 having42.91MMbb of oil and recoverable reserve of 13.63MMbbl. OJ-04 is equally productive with 40.58MMbbl and112.74MMcf of oil and gas respectively with recoverable reserve of 3.77MMbbl while OJ-03 is the least promisingwell with 13.52MMbbl of oil that yielded recoverable reserve of 1.96MMbbl. The total net volume of the reservoirsyielded stock tank oil in place of 162.98MMbbl and gas in place of 112.74MMcf. Only, 24.58MMbbl can berecovered from the stock tank oil in place estimated and this is attributed to insufficient drive mechanism and highviscosity
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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