1,721,032 research outputs found
Geolithological and anthropogenic controls on the hydrochemistry of the Volturno river (Southern Italy)
No full textThe present work aims to study the main chemical and physical water parameters in the upper and middle Volturno river catchment (southern Italy), between the Capo Volturno springs and the confluence with the Calore river. This study makes use of morphology, geolithology, tectonic, land use, and physico-chemical (pH, electrical conductivity, redox potential, temperature, major ions, and Rn-222) data for the identification of the main sources of surface and groundwaters in the Volturno catchment and of their evolution and mixing both in base flow and peak flow conditions. The study was also performed to assess whether the alteration due to potential anthropogenic contamination may hamper the identification of natural primitive sources of surface waters, especially in the populated and farmed plains far from the river headwaters. Our data suggest that water chemistry of this stretch of the Volturno river is dominated mainly by lithology and, only marginally, by the intense exogenous activities and that this trend is appreciable in both base flow and peak flow conditions. The proposed simple geochemical approach based on easy-to-sample matrices and on cost-effective standard methods is a valuable tool to address catchment functionality especially in upland areas, where complex geologic and structural settings, heterogeneous groundwater flow, and logistical issues are the rule rather than the exception. Because the upper and middle Volturno catchment is comparable with numerous valleys of the Mediterranean area, this study could be a reference for analogous applications
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
Examining the Geological Potential for Helium Production in the United States
Get PDFGlobal helium demand has more than doubled throughout the last twenty years in response to the development of new manufacturing and scientific research techniques. In fact, data collected by the National Science Academies have shown that global demand for helium is likely to outstrip global supply by 2020. Despite these rapid increases in helium demand and the looming shortfall in helium supplies, recent United States federal legislation has mandated the deregulation of the U.S. federal helium reserve managed by the U.S. Bureau of Land Management. Because the United States has been a global leader in the recovery and storage of helium since the early 1900s, and continues to be the leading global producer and reserve holder of helium today, this decision has created considerable uncertainty in global helium markets. As a result, other countries such as Qatar, Algeria, and Russia have begun to develop their own helium resources. These changes in global helium markets highlight the need to better characterize domestic unconventional helium reserves globally. This research examines the potential for helium production in the United States.Chevron USANo embarg
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
Thermal Maturity, Composition, and Origin of the Hydrocarbon Gases of the Eagle Ford Shale in Texas, USA
Get PDFThe Eagle Ford Shale, a high-growth and profitable developing play, locates mainly in South Texas. Even though it has been actively developed for about 9 years, to reduce industrial exploitation risk, properties of the fluids in the Eagle Ford Shale still need to be studied. In this research, samples of oil and associated gases collected from 27 hydraulically fractured horizontal commercial wells were analyzed for major gas compositions and stable carbon isotopic ratios to characterize the natural gases of the Eagle Ford Shale.
The experimental data suggest that natural gases of the Eagle Ford Shale are thermogenic, oil-associated wet gas in early stage of thermal maturity for four reasons: 1) large amount of ethane and heavier aliphatic hydrocarbons (0.11≤C2+/C1≤1.4); 2) the stable carbon isotopic composition of methane and ethane (-48<13C1 (‰)<-36 and -36.7<13C2 (‰)<-33.93); 3)vitrinite reflectance values (0.61<Ro<0.96) calculated from carbon isotope ratios of methane and ethane using two individual equations developed by Whiticar et al., 1994; 4) the sublinear nature of Chung Plot.NSF EAGER 1249255NSF SusChEM 1441497No embarg
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