1,720,970 research outputs found
Experiments on methane hydrates formation in seabed deposits and gas recovery adopting carbon dioxide replacement strategies
No full textTopic of this work is to carry out studies to deepen the knowledge of the CO2-CH4 replacement process, using a laboratory scale apparatus designed to reproduce marine hydrate sediments. Nine tests were performed, at three different hydrate saturation levels: 10, 20 and 30%. Temperature profiles over time allow to determine the spatial distribution of the formed hydrates in the sediment. At 10% and 20% hydrates saturation the reaction always starts in the upper part of the reactor, but the massive formation occurred in the lower and the middle area. When saturation reached 30%, reaction heat was mainly produced in the upper part of the reactor. Three CO2-CH4 replacement tests were carried out at 10% hydrate saturation. During the tests both temperature and pressure were modified to cause the CH4 hydrates dissociation and the CO2 hydrates formation. At the end of the replacement process, CO2 stored was in the range 31–42% of the total CO2 injected, and the exchange efficiency was in the range 1.30–1.45
A Brief Overview of Lab - Scale Apparatuses Used in the Recent Years for Experimental Investigations on Gas Hydrates
No full textGas hydrates are nonstoichiometric solid crystalline compound, whose formation is a function of several parameters, such as pressure, temperature, fluid phase composition, reservoir saturation degree and others. One of the most critical aspects related to the research on this manner stays in differences existing between experimental results reached by using different experimental apparatuses. Moreover, laboratory scale reactors often have very contained dimensions with a consequent increasing influence of the boundary conditions. In the present paper, a brief overview of reactors used worldwide for experimental research on gas hydrates formation, is provided. In particular, the surface/volume ratio was calculated for each different typology of reactor and then associated with the ratio between moles of guest compound entrapped into water cages and moles injected. Even if such a ratio does not represent the process efficiency, it is proportional to it. Consequently, that comparison was useful to well define the supporting effect of a greater S/V ratio on the hydrate formation process efficiency
sj-docx-1-pie-10.1177_09544089221150703 - Supplemental material for Investigations on erosion performance of carbon fiber–epoxy-based composite adhesion on 16Cr5Ni steel
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089221150703 for Investigations on erosion performance
of carbon fiber–epoxy-based composite adhesion on 16Cr5Ni steel by Mithlesh Sharma, Deepak Kumar Goyal, Anuj Bansal, Anil Kumar Singla, Neel Kanth Grover, Munish Kumar Gupta and Navneet Khanna in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
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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