1,721,008 research outputs found
Facilitatory interaction between cutaneous afferents from low threshold mechanoreceptors and nociceptors in segmental reflex pathways to alpha-motoneurons
No full textEPSPs evoked by air puff stimulation of the hairy skin of the hindlimb or by low strength stimulation of the lateral sural nerve were facilitated by radiant heat of 50-53 degrees C but not by radiant heat of 42-43 degrees C. The results indicate that afferents from low threshold mechanoreceptors and from nociceptors of the skin converge onto common interneurons in reflex pathways to alpha-motoneurons. This would allow a functionally useful cooperation of these two types of afferents in spinal motor control
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
Metallurgical processing of zinc-bearing residues
No full textIn this study metallurgical processing of two different kinds of zinc-bearing residues have been performed: Zinc A and Zinc B. These residues have been stored for over 15 years in Rotterdam Harbor. The chemical compositions of the residues have been determined and showed that zinc ferrite is a major phase present. Zinc ferrite is not soluble under normal alkaline and acidic conditions and is not recovered by the Waelz-process, which is commonly employed for such zinc-bearing residues. An innovative flowsheet for processing zinc ferrite-bearing residues has been developed during a pre-feasibility study, with goal to selectively recover zinc, including zinc from zinc ferrite. The innovative flowsheet consists of the following steps: (1) Water pre-washing: removing water soluble salts, in particular the chlorides in Zinc A (~9%). (2) 1st step alkaline leaching with caustic soda (NaOH): dissolving free ZnO into solution, for both water-washed Zinc A and original (unwashed) Zinc B. (3) Roasting of the first leach residue in the presence a suitable reagent: decomposing the zinc ferrite to free ZnO. (4) 2nd step alkaline leaching with NaOH: dissolving all free ZnO into solution. (5) Solution purification by cementation: removing impurities in particular lead and copper, by using zinc powder. (6) Electrowinning of zinc in NaOH solution: the purified zinc bearing solutions are subsequently precipitated to the final product of Zn metal. Optimal operating conditions for the processes are deduced from a literature review in which similar residues are processed. Additionally, optimal operating conditions for the conversion of zinc ferrite into zinc oxide has been investigated using synthetic zinc ferrite with addition of Mg(OH)2, Ca(OH)2, NaOH, or Na2CO3. Finally, Na2CO3 has been chosen as reagent and used in experiments with real zinc-bearing residues. Zinc A is water washed to remove the chlorides present. Then both the water washed residue of Zinc A, and Zinc B, are leached in an alkaline solution of 5M NaOH at 90?C for 1 hour. Both zinc and lead are selectively extracted, leaving iron oxides and zinc ferrite in the residue. The filtercake is fused with Na2CO3 at 950?C for 2 hours to convert zinc ferrite into zinc oxide. The calcined product is leached in fresh alkaline solution of 5M NaOH to recover zinc. The final residue is then water washed to remove residual sodium. The filtrates from the first and second leaching step are purified, with use of zinc dust, or directly used for electrowinning experiments. The removal efficiency of chloride, sodium and potassium during water washing of Zinc A were 62%, 41% and 71% respectively. Overall dissolution yields for Zinc A and Zinc B of zinc and lead were 82%, 80% and 64%, 78% respectively. Cementation of impurities (Pb, Cu, Cr) with zinc dust followed by an electrowinning step achieving a grade zinc deposit of 94%. Finally, it can be concluded that the combined hydro -and pyrometallurgical flowsheet is technically feasible. Furthermore, results can be improved further by optimization of major operating steps.Mineral EngineeringResource EngineeringCivil Engineering and Geoscience
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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