1,720,956 research outputs found
Some characterization and beneficiation data on phosphorites from Parc-W, Niger
No full textPhosphate ore from Parc W, Niger, is siliceous and varies from medium to high grade (26%
-35 % P70,). Mineralogicaily, the silica and phosphate combined represent 85 % -95 % of the ore ; the remainder consists mainly of clays and micas. The rocks are metasediments that contain angular-to-rounded phosphate pellets. The phosphate and detrital quartz are tightly cemented by a cherty-quartz matrix. The francolites also show low carbonate-for-phosphate substitution. The compact textures and the small size of the phosphate cause liberation from the silica to occur at small particle sizes (75-150 pm). Flotation of the Parc W rock (28 % P -O .) produced concentrates containing 30 % -32 % P2O5 an< recovery of 70%
-80 %.Le minerai de phosphate du Parc du W au Niger est siliceux et sa teneur en P2O5 est de moyenne à élevée (26 % -35 %). Du point de vue minéralogique, silice et phosphate représentent à eux seuls 85 % à 95 % du minerai ; le reste est surtout constitué de minéraux argileux et de micas. Les roches sont des métasédiments contenant des grains de phosphate angulaires à arrondis. Phosphate et quartz détritique sont totalement cimentés par une matrice cherto-quartzeuse. Les francolites présentent une faible substitution du phosphate par du carbonate. A cause des textures compactes et de la petite taille des phosphates, la séparation d'avec la silice ne peut être faite qu'à des tailles granulométriques faibles (75 -150 pm). La fiottation de la roche à 28'% P- ?Oc fournit un concentré à 30 % -32 % avec une récupération
de 70 % -80 %.McClellan Guerry, Cooper Michelle, Lawendy Talaat, Anazia Ibezim. Some characterization and beneficiation data on phosphorites from Parc-W, Niger. In: Phosphorites. Sixth International Field-Workshop and Seminar on Phosphorites. I.G.C.P. 156. Maroc-Sénégal, oct.-nov. 1983. Strasbourg : Institut de Géologie – Université Louis-Pasteur, 1985. pp. 135-141. (Sciences Géologiques. Mémoire, 77
Some characterization, calcination and beneficiation data on a phosphorite from the Kaiyang area of Guizhou, China
No full textThe Kaiyang ore is a mixture (nearly 1 : 1) of phosphate (francolite) and dolomite. The francoli-te occurs as pellets (100-350 цт) and massive irregular bands in a dolomitic matrix.
Calcination was used to decompose the dolomite to CaO and MgO, which were then removed by slaking and attrition scrubbing. The MgO content as reduced from 12.3 % in the ore to 2.6 % in the product. The P2O5 rac'e increased from 17.6 % in the ore to 34.8 % in the product with a 76 % phosphate recovery.
Removal of the dolomite from the Kaiyang ore by flotation yielded concentrates assaying 35.6 % P -Cb and 1.1 % MgO (from deslimed flotation feed of 23.9 % P2O5 and 7.5 % MgO) with 60 % -70 % phosphate recovery.Le minerai de Kaiyang est un mélange à parts pratiquement égales de phosphate (francolite) et de dolomite. La francolite se présente sous forme de grains (100 -350 pm) et en lits massifs irréguliers dans une matrice dolomitique.
Par calcination on a décomposé la dolomite en CaO et MgO, qui ont été ensuite séparés par hydratation et lavage en suspension dans l'eau. La teneur en MgO a été réduite de 12.3 % dans le minerai à 2.6 % dans le produit calciné. La teneur en P2O5 a augmenté de 17.6 % dans le minerai à 34.8 % dans le produit final, avec un taux de récupération du phospnate de 76 %.
L'élimination par flottation de la dolomite du minerai de Kaiyang a produit des concentrés titrant 35.6 % de P2O5 et 1,1 % de MgO (à partir d'une alimentation en produit débourbé à 23,9 % P2C5 et 7, 5 % MgO), avec un taux de récupération de phosphate de 60 à 70 %.McClellan Guerry, Roy Amitava, Lawendy Talaat, Chen Ming-Rei. Some characterization, calcination and beneficiation data on a phosphorite from the Kaiyang area of Guizhou, China. In: Phosphorites. Sixth International Field-Workshop and Seminar on Phosphorites. I.G.C.P. 156. Maroc-Sénégal, oct.-nov. 1983. Strasbourg : Institut de Géologie – Université Louis-Pasteur, 1985. pp. 125-134. (Sciences Géologiques. Mémoire, 77
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
Petrology of Attapulgus Clay in North Florida and Southwest Georgia
No full textMade available in DSpace on 2014-12-09T20:34:13Z (GMT). No. of bitstreams: 1
6503634.pdf: 4244599 bytes, checksum: d740862c2d6e45fb138c9e4c3c907269 (MD5)
Previous issue date: 1964Embargo set by: Seth Robbins for item 61584
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only127 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1964
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