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An Investigation of Chrysocolla Flotation Using N-Octanohydroxamate Collector
No full textThis thesis presents the results of an investigation of chrysocolla flotation using n-octanohydroxamate collector. The complex formation and bonding behaviour of copper (II) hydroxamate and iron (III) hydroxamate were investigated. Acid-base titration analyses indicated that copper acetohydroxamate and copper octanohydroxamate complexes formed with a 1: 1 (copper: hydroxamate) stoichiometry. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and Atomic absorption spectroscopy (AAS) analyses were in agreement with the result. For the copper benzohydroxamate complex, acid-base titration analyses indicated a 1: 2 (copper: hydroxamate) stoichiometry. AAS analyses confirmed the stoichiometric ratio of 1: 2 (copper: hydroxamate). Raman and FTIR analyses were consistent with the results from the titration and AAS analyses.
Iron (III) complexes with acetohydroxamate, benzohydroxamate and n-octanohydroxamate were characterised by using acid-base titrations. The titration graph results from the three complexes indicated a 1: 3 (iron: hydroxamate) stoichiometry. AAS analyses indicated the same result. Raman and FTIR analyses exhibited the molecular structure which supported a 1: 3 (iron: hydroxamate) stoichiometry.Thesis (PhD Doctorate)Doctor of Philosophy (PhD)School of Biomolecular and Physical SciencesScience, Environment, Engineering and TechnologyFull Tex
Binary skeletal copper-cobalt catalysts
Get PDFBinary skeletal metal catalysts were made by starting with a ternary alloy. The precursor alloys and catalysts were characterised using Optical Microscopy, X-ray Diffractometer, Scanning Electron Microscopy, Inductively Coupled Plasma (ICP) and BET surface area in term of morphologies, phase identification, surface area and pore structure.
Skeletal copper catalyst presented high surface areas and consisted primarily of CuAl2 grains, with small well-dispersed areas of the Al-CuAl2 eutectic. The CuAl2 phase, which represented a tetragonal structure, showed large cell volumes resulted in a fine skeleton structure. Binary nickel-copper catalyst composed of three majority phases including Ni2Al3, Cu4NiAl7 and Al. The Cu4NiAl7 was found to be a caustic resistant phase which led to low surface area in the nickel-copper catalyst
In terms of the selective removal of aluminium from the copper-cobalt-aluminium alloy to create the binary copper-cobalt catalyst, 11 alloy samples with various compositions were produced following the ternary phase diagram. The surface area and pore size of these catalysts was dependant on the crystal structure of the phases present and the amount of remaining Al. Electrochemical glucose oxidation and carbon dioxide reduction activity have been used for testing the catalyst performance.
The electrochemical oxidation of glucose experiment using 11 samples of skeletal Cu-Co catalyst as an electrode showed the results that the significant oxidation peaks were observed in sample 1, 4, 8, 9 and the small oxidation humps were observed in other sample except sample 2. These small peaks resulted from that the glucose molecule had difficulty to absorb on the surface area of the skeletal Cu-Co catalysts electrode. The difficulty may results from very fine pore volume and pore size of the catalysts. In term of assessing the skeletal Cu-Co catalyst with electrochemical reduction of carbon dioxide experiment, the skeletal Cu-Co catalyst sample 7 which presented the highest surface area was selected as an electrode to compare with Cu foil electrode. The result of using skeletal Cu-Co as an electrode indicated significantly higher current. This results from that a skeletal Cu-Co catalyst electrode presented an actual high surface area which leads to more adsorbed regions
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
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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